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1.
Laryngoscope ; 131(2): E452-E458, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32396214

RESUMEN

OBJECTIVES/HYPOTHESIS: Squamous cell carcinoma of the hypopharynx (SCCHP) is associated with worse survival compared to other head and neck subsites. This report quantifies the impact of technological improvements in radiotherapy (RT) on outcomes over 6 decades. METHODS: Patients with SCCHP receiving curative-intent treatment between 1962 and 2015 were retrospectively reviewed. Kaplan-Meier analyses of freedom from local recurrence (FFLR), progression-free survival (PFS), and overall survival (OS) were compared across treatment eras and radiation techniques. Multivariable Cox proportional hazards modeling was performed to specify the effect of RT technique. RESULTS: One hundred thirty-four patients had a median follow-up of 17 months (IQR = 9-38). There were no differences in staging or use of surgery over time, but use of chemotherapy concurrent with RT increased (P < .001) beginning in the 2000s. The 24-month FFLR using two-dimensional RT (2D-RT), three-dimensional conformal RT (3D-CRT), and intensity-modulated RT (IMRT) was 52%, 55%, and 80%, respectively; 24-month PFS was 39%, 46%, and 73%, respectively; and 24-month OS was 27%, 40%, and 68%, respectively. OS (P = .01), PFS (P = .03), and FFLR (P = 0.02) were improved with IMRT over 2D-RT, and FFLR appeared to be improved over 3D-CRT (P = .06). Controlling for chemotherapy use and other major variables, IMRT produced a strong influence over FFLR (adjusted hazard ratio [HR] = 0.2, 95% confidence interval [CI]: 0.0-1.2, P = .08) and a benefit in OS (adjusted HR = 0.1, 95% CI: 0.0-0.4, P = .005). CONCLUSIONS: Across 6 decades, patient and tumor characteristics remained similar whereas use of chemoradiation increased and IMRT was adopted. The introduction of IMRT was associated with improved FFLR, PFS, and OS, and a reduction in acute toxicity as compared to earlier radiation technologies. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E452-E458, 2021.


Asunto(s)
Carcinoma de Células Escamosas/radioterapia , Neoplasias Hipofaríngeas/radioterapia , Carcinoma de Células Escamosas/mortalidad , Femenino , Humanos , Neoplasias Hipofaríngeas/mortalidad , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/epidemiología , Supervivencia sin Progresión , Mejoramiento de la Calidad , Estudios Retrospectivos , Análisis de Supervivencia
2.
Am J Ophthalmol Case Rep ; 19: 100787, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32760850

RESUMEN

PURPOSE: To describe the first series of six young uveal melanoma (UM) patients with oral isotretinoin and/or topical retinoid therapy prior to diagnosis. OBSERVATIONS: The case series is based on clinical observations at our UM quaternary referral center. Six UM patient cases are reported, ages 16-44 years old. All had been using either oral (isotretinoin) and/or topical (tretinoin or tazarotene) retinoid treatment (3 months-~10 years) prior to or at the time of diagnosis (3 of 6 cases). All patients had ocular complaints on presentation, and the onset of certain symptoms corresponded with the course of retinoids. Other potential risk factors or relevant history included Caucasian background, cone-rod dystrophy and active smoker status (Case 2), family history of UM and pregnancy at time of diagnosis (Case 3), past smoking and possible secondary Chernobyl exposure as a baby (Case 5). All patients were treated with proton beam radiotherapy and currently have no sign of recurrent or metastatic disease. CONCLUSIONS AND IMPORTANCE: Retinoid therapy has been linked to various benign and/or reversible effects on the anterior and posterior eye, though pathophysiology remains not well understood. Uveal melanoma (UM) is a rare cancer diagnosis in young adults. We report here the first case series of young UM patients with a history of retinoid use and ocular complaints. No causal link is claimed and further systematic epidemiologic and biologic study of retinoid therapy and ocular impact may provide additional relevant data, particularly in young ocular melanoma patients.

3.
Radiother Oncol ; 90(2): 213-20, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18926579

RESUMEN

PURPOSE: To determine the radiation dose to the carotid artery in nasopharyngeal cancer patients treated with intensity-modulated radiotherapy (IMRT) and to compare it to the dose delivered by a conventional three-field (3F) technique. MATERIALS AND METHODS: Sixteen patients with nasopharyngeal cancer who were treated at UCSF with IMRT were selected for this analysis. 3F plans were reconstructed for comparison. The carotid arteries were retrospectively contoured, and the dose received by each of the 32 carotid arteries was determined for both IMRT and 3F plans. A subset of 8 patients with N0/N1 nodal disease was selected for IMRT replanning using additional constraints to reduce the dose to the arteries. RESULTS: Using the standard prescription doses for IMRT and 3F plans, the dose delivered to 95% of the tumor volume was significantly higher in the IMRT plans, reflecting the greater conformality of this technique. The median mean dose to the carotid arteries was 65.7Gy with IMRT vs. 58.4Gy with 3F (p<0.001). After the application of dose constraints to the carotid arteries, it was possible to reduce the mean carotid dose to 54Gy in the IMRT replans. CONCLUSIONS: IMRT achieves a higher tumoricidal dose and superior clinical target volume coverage, but results in an increase in the carotid artery dose as compared to conventional 3F technique. With careful IMRT planning, it is possible to constrain the carotid dose for a subset of patients with low-risk neck disease. Further study is necessary to quantify the long-term clinical impact of this intervention.


Asunto(s)
Arterias Carótidas/efectos de la radiación , Neoplasias Nasofaríngeas/radioterapia , Dosis de Radiación , Radioterapia de Intensidad Modulada , Humanos , Planificación de la Radioterapia Asistida por Computador
4.
Med Phys ; 45(3): 1036-1039, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29377168

RESUMEN

PURPOSE: The purpose of this study is to explore the feasibility of the use of titanium fiducial markers to minimize the metallic artifact seen with tantalum markers which causes significant distortion on postoperative orbital CT scans. METHOD: We designed and constructed the titanium markers in the shop of Crocker Nuclear Laboratory, UC Davis, CA. The markers were placed on an eyeball phantom. The eyeball was inserted into the Rando phantom in the orbital space. The Rando phantom was imaged with coplanar x rays on Nucletron simulator at UCSF, on digital panel on the eye beam line at CNL eye treatment facility and on CT scanner at UCSF. RESULTS: The titanium markers can be clearly seen on the hard copy of x rays and on digital panel. The CT scan of an orbit using tantalum markers on the right eye and titanium markers on the left eye shows the metal artifact from tantalum markers. Titanium markers show very little distortion on CT images. CONCLUSION: The present study describes these markers and their relative benefit in comparison with tantalum marker, which has been used for localizing ocular tumor for decades.


Asunto(s)
Neoplasias de la Coroides/radioterapia , Marcadores Fiduciales , Melanoma/radioterapia , Terapia de Protones , Titanio , Neoplasias de la Coroides/diagnóstico por imagen , Estudios de Factibilidad , Humanos , Melanoma/diagnóstico por imagen , Tomografía Computarizada por Rayos X
5.
Int J Radiat Oncol Biol Phys ; 67(1): 138-43, 2007 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-17049183

RESUMEN

PURPOSE: To evaluate the impact of postoperative radiation therapy on the clinical course of patients with carcinoma ex pleomorphic adenoma of the parotid gland. METHODS AND MATERIALS: Between 1960 and 2004, 63 patients were treated with definitive surgery for carcinoma ex pleomorphic adenoma of the parotid gland. Forty patients (63%) received postoperative radiation therapy to a median dose of 60 Gy (range, 45-71 Gy). Adenocarcinoma (29 patients), salivary duct carcinoma (16 patients), and adenoid cystic carcinoma (9 patients) were the most common malignant subtypes. Pathologic T -stage was: 16% T1, 33% T2, 32% T3, and 19% T4. Twenty-one patients (33%) had microscopically positive margins and 39 (62%) had perineural invasion. Median follow-up was 50 months (range, 2-96 months). RESULTS: The use of postoperative therapy significantly improved 5-year local control from 49% to 75% (p = 0.005) and was associated with an improvement in survival among patients without evidence of cervical lymph node metastasis (p = 0.01). A Cox proportional hazard model identified pathologic involvement of cervical lymph nodes as an independent predictor of overall survival. Overall survival was 16% for patients with pathologic N-positive disease compared with 67% for those whose lymph node status was negative or unknown (p = 0.001). CONCLUSION: Surgery followed by postoperative radiation should be considered the standard of care for patients with carcinoma ex pleomorphic adenoma.


Asunto(s)
Adenoma Pleomórfico/radioterapia , Neoplasias de la Parótida/radioterapia , Adenocarcinoma/mortalidad , Adenocarcinoma/radioterapia , Adenocarcinoma/cirugía , Adenoma Pleomórfico/mortalidad , Adenoma Pleomórfico/cirugía , Adulto , Anciano , Carcinoma Adenoide Quístico/mortalidad , Carcinoma Adenoide Quístico/radioterapia , Carcinoma Adenoide Quístico/cirugía , Terapia Combinada/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias de la Parótida/mortalidad , Neoplasias de la Parótida/cirugía , Periodo Posoperatorio , Dosificación Radioterapéutica , Conductos Salivales , Neoplasias de las Glándulas Salivales/mortalidad , Neoplasias de las Glándulas Salivales/radioterapia , Neoplasias de las Glándulas Salivales/cirugía
6.
Int J Radiat Oncol Biol Phys ; 68(3): 809-16, 2007 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-17363191

RESUMEN

PURPOSE: The optimal strategy for treating locally advanced pancreatic cancer remains controversial, including the respective roles and timing of chemotherapy and radiation. We conducted a Phase II nonrandomized trial to evaluate sequential chemotherapy followed by chemoradiation in this patient population. METHODS AND MATERIALS: Chemotherapy naive patients with locally advanced pancreatic adenocarcinoma were treated with fixed-dose rate gemcitabine (1,000 mg/m(2) at 10 mg/m(2)/min) plus cisplatin 20 mg/m(2) on Days 1 and 15 of a 28-day cycle. Those without evidence of extrapancreatic metastases after six cycles of chemotherapy received radiation (5,040 cGy over 28 fractions) with concurrent capecitabine (800 mg/m(2) orally twice daily on the day of radiation) as a radiosensitizer. RESULTS: A total of 25 patients were enrolled with a median follow-up time of 656 days. Twelve patients (48%) successfully received all six cycles of chemotherapy plus chemoradiation. Eight patients (32%) progressed during chemotherapy, including 7 with extrapancreatic metastases. Grade 3/4 hematologic toxicities were uncommon. Two patients sustained myocardial infarctions during chemotherapy, and 4 were hospitalized for infectious complications, although none in the setting of neutropenia. Median time to progression was 10.5 months and median survival was 13.5 months, with an estimated 1-year survival rate of 62%. Patients receiving all components of therapy had a median survival of 17.0 months. CONCLUSIONS: A strategy of initial fixed-dose rate gemcitabine-based chemotherapy, followed by chemoradiation, shows promising efficacy for treatment of locally advanced disease. A substantial proportion of patients will be identified early on as having extrapancreatic disease and spared the potential toxicities associated with radiation.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Recurrencia Local de Neoplasia/mortalidad , Neoplasias Pancreáticas/mortalidad , Neoplasias Pancreáticas/terapia , Traumatismos por Radiación/epidemiología , Radioterapia Adyuvante/mortalidad , Adulto , Anciano , Anciano de 80 o más Años , Antimetabolitos Antineoplásicos/administración & dosificación , California/epidemiología , Cisplatino/administración & dosificación , Comorbilidad , Desoxicitidina/administración & dosificación , Desoxicitidina/análogos & derivados , Relación Dosis-Respuesta a Droga , Femenino , Enfermedades Gastrointestinales/epidemiología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/prevención & control , Neoplasias Pancreáticas/cirugía , Pronóstico , Fármacos Sensibilizantes a Radiaciones/administración & dosificación , Medición de Riesgo/métodos , Factores de Riesgo , Análisis de Supervivencia , Tasa de Supervivencia , Resultado del Tratamiento , Gemcitabina
7.
Int J Radiat Oncol Biol Phys ; 69(1): 141-7, 2007 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-17459609

RESUMEN

PURPOSE: To compare clinical outcomes of patients with carcinomas of the paranasal sinuses and nasal cavity according to decade of radiation treatment. METHODS AND MATERIALS: Between 1960 and 2005, 127 patients with sinonasal carcinoma underwent radiotherapy with planning and delivery techniques available at the time of treatment. Fifty-nine patients were treated by conventional radiotherapy; 45 patients by three-dimensional conformal radiotherapy; and 23 patients by intensity-modulated radiotherapy. Eighty-two patients (65%) were treated with radiotherapy after gross total tumor resection. Nineteen patients (15%) received chemotherapy. The most common histology was squamous cell carcinoma (83 patients). RESULTS: The 5-year estimates of overall survival, local control, and disease-free survival for the entire patient population were 52%, 62%, and 54%, respectively. There were no significant differences in any of these endpoints with respect to decade of treatment or radiotherapy technique (p > 0.05, for all). The 5-year overall survival rate for patients treated in the 1960s, 1970s, 1980s, 1990s, and 2000s was 46%, 56%, 51%, 53%, and 49%, respectively (p = 0.23). The observed incidence of severe (Grade 3 or 4) late toxicity was 53%, 45%, 39%, 28%, and 16% among patients treated in the 1960s, 1970s, 1980s, 1990s, and 2000s, respectively (p = 0.01). CONCLUSION: Although we did not detect improvements in disease control or overall survival for patients treated over time, the incidence of complications has significantly declined, thereby resulting in an improved therapeutic ratio for patients with carcinomas of the paranasal sinuses and nasal cavity.


Asunto(s)
Cavidad Nasal , Neoplasias Nasales/radioterapia , Neoplasias de los Senos Paranasales/radioterapia , Adenocarcinoma/mortalidad , Adenocarcinoma/radioterapia , Adenocarcinoma/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Adenoide Quístico/mortalidad , Carcinoma Adenoide Quístico/radioterapia , Carcinoma Adenoide Quístico/cirugía , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/radioterapia , Carcinoma de Células Escamosas/cirugía , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Neoplasias Nasales/mortalidad , Neoplasias Nasales/cirugía , Neoplasias de los Senos Paranasales/mortalidad , Neoplasias de los Senos Paranasales/cirugía , Traumatismos por Radiación/prevención & control , Radioterapia/efectos adversos , Radioterapia/tendencias , Radioterapia Conformacional/efectos adversos , Radioterapia de Intensidad Modulada/efectos adversos , Factores de Tiempo , Resultado del Tratamiento
8.
Med Phys ; 34(8): 3233-42, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17879786

RESUMEN

Accuracy of treatment setup for head and neck patients undergoing intensity-modulated radiation therapy is of paramount importance. The conventional method using orthogonal portal images can only detect translational setup errors while the most frequent setup errors for head and neck patients could be rotational errors. With the rapid development of image-guided radiotherapy, three-dimensional images are readily acquired and can be used to detect both translational and rotational setup errors. The purpose of this study is to determine the significance of rotational variations between two planning CT scans acquired for each of eight head and neck patients, who experienced substantial weight loss or tumor shrinkage. To this end, using a rigid body assumption, we developed an in-house computer program that utilizes matrix transformations to align point bony landmarks with an incremental best-fit routine. The program returns the quantified translational and rotational shifts needed to align the scans of each patient. The program was tested using a phantom for a set of known translational and rotational shifts. For comparison, a commercial treatment planning system was used to register the two CT scans and estimate the translational errors for these patients. For the eight patients, we found that the average magnitudes and standard deviations of the rotational shifts about the transverse, anterior-posterior, and longitudinal axes were 1.7 +/- 2.3 degrees, 0.8 +/- 0.7 degrees, and 1.8 +/- 1.1 degrees, respectively. The average magnitudes and standard deviations of the translational shifts were 2.5 +/- 2.6 mm, 2.9 +/- 2.8 mm, 2.7 +/- 1.7 mm while the differences detected between our program and the CT-CT fusion method were 1.8 +/- 1.3 mm, 3.3 +/- 5.4 mm, and 3.0 +/- 3.4 mm in the left-right, anterior-posterior, and superior-inferior directions, respectively. A trend of larger rotational errors resulting in larger translational differences between the two methods was observed. In conclusion, conventional methods used for verifying patient positioning may misinterpret rotational shifts as translational shifts, and our study demonstrated that rotational errors may be significant in the treatment of head and neck cancer.


Asunto(s)
Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Neoplasias de Cabeza y Cuello/diagnóstico , Planificación de la Radioterapia Asistida por Computador/métodos , Tomografía Computarizada por Rayos X/métodos , Algoritmos , Análisis de Falla de Equipo , Humanos , Imagenología Tridimensional , Modelos Estadísticos , Fantasmas de Imagen , Dosificación Radioterapéutica , Radioterapia de Intensidad Modulada/métodos , Reproducibilidad de los Resultados , Tomógrafos Computarizados por Rayos X
9.
J Appl Clin Med Phys ; 8(2): 26-36, 2007 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-17592464

RESUMEN

The first aim of the present study was to investigate the feasibility of using fewer beam angles to improve delivery efficiency for the treatment of oropharyngeal cancer (OPC) with inverse-planned intensity-modulated radiation therapy (IP-IMRT). A secondary aim was to evaluate whether the simplified IP-IMRT plans could reduce the indirect radiation dose. The treatment plans for 5 consecutive OPC patients previously treated with a forward-planned IMRT (FP-IMRT) technique were selected as benchmarks for this study. The initial treatment goal for these patients was to deliver 70 Gy to > or = 95% of the planning gross tumor volume (PTV-70) and 59.4 Gy to > or = 95% of the planning clinical tumor volume (PTV-59.4) simultaneously. Each case was re-planned using IP-IMRT with multiple beam-angle arrangements, including four complex IP-IMRT plans using 7 or more beam angles, and one simple IMRT plan using 5 beam angles. The complex IP-IMRT plans and simple IP-IMRT plans were compared to each other and to the FPIMRT plans by analyzing the dose coverage of the target volumes, the plan homogeneity, the dose-volume histograms of critical structures, and the treatment delivery parameters including delivery time and the total number of monitor units (MUs). When comparing the plans, we found no significant difference between the complex IP-IMRT, simple IP-IMRT, and FP-IMRT plans for tumor target coverage (PTV-70: p = 0.56; PTV-59.4: p = 0.20). The plan homogeneity, measured by the mean percentage isodose, did not significantly differ between the IP-IMRT and FP-IMRT plans (p = 0.08), although we observed a trend toward greater inhomogeneity of dose in the simple IP-IMRT plans. All IP-IMRT plans either met or exceeded the quality of the FP-IMRT plans in terms of dose to adjacent critical structures, including the parotids, spinal cord, and brainstem. As compared with the complex IP-IMRT plans, the simple IP-IMRT plans significantly reduced the mean treatment time (maximum probability for four pairwise comparisons: p = 0.0003). In conclusion, our study demonstrates that, as compared with complex IP-IMRT, simple IP-IMRT can significantly improve treatment delivery efficiency while maintaining similar target coverage and sparing of critical structures. However, the improved efficiency does not significantly reduce the total number of MUs nor the indirect radiation dose.


Asunto(s)
Modelos Biológicos , Neoplasias Orofaríngeas/radioterapia , Radiometría/métodos , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia Conformacional/métodos , Carga Corporal (Radioterapia) , Simulación por Computador , Humanos , Dosificación Radioterapéutica , Efectividad Biológica Relativa
10.
Int J Radiat Oncol Biol Phys ; 97(1): 91-97, 2017 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-27838186

RESUMEN

PURPOSE: To perform an in-depth temporal analysis of visual acuity (VA) outcomes after proton beam radiation therapy (PBRT) in a large, uniformly treated cohort of uveal melanoma (UM) patients, to determine trends in VA evolution depending on pretreatment and temporally defined posttreatment VA measurements; and to investigate the relevance of specific patient, tumor and dose-volume parameters to posttreatment vision loss. METHODS AND MATERIALS: Uveal melanoma patients receiving PBRT were identified from a prospectively maintained database. Included patients (n=645) received 56 GyE in 4 fractions, had pretreatment best corrected VA (BCVA) in the affected eye of count fingers (CF) or better, with posttreatment VA assessment at specified post-PBRT time point(s). Patients were grouped according to the pretreatment BCVA into favorable (≥20/40) or unfavorable (20/50-20/400) and poor (CF) strata. Temporal analysis of BCVA changes was described, and univariate and forward stepwise multivariate logistic regression analyses were performed to identify predictors for VA loss. RESULTS: Median VA follow-up was 53 months (range, 3-213 months). At 60-month follow up, among evaluable treated eyes with favorable pretreatment BCVA, 45% retained BCVA ≥20/40, whereas among evaluable treated eyes with initially unfavorable/poor BCVA, 21% had vision ≥20/100. Among those with a favorable initial BCVA, attaining BCVA of ≥20/40 at any posttreatment time point was associated with subsequent maintenance of excellent BCVA. Multivariate analysis identified volume of the macula receiving 28GyE (P<.0001) and optic nerve (P=.0004) as independent dose-volume histogram predictors of 48-month post-PBRT vision loss among initially favorable treated eyes. CONCLUSIONS: Approximately half of PBRT-treated UM eyes with excellent pretreatment BCVA assessed at 5 years after treatment will retain excellent long-term vision. 28GyE macula and optic nerve dose-volume histogram parameters allow for rational treatment planning optimization that may lead to improved visual outcomes. The detailed temporal analysis with intermediate as well as long-term functional prognosis, and the relationship of outcomes with clinical and treatment planning parameters, is critical for informed care of UM patients before and after PBRT.


Asunto(s)
Melanoma/radioterapia , Tratamientos Conservadores del Órgano/métodos , Terapia de Protones/métodos , Neoplasias de la Úvea/radioterapia , Agudeza Visual/efectos de la radiación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Fraccionamiento de la Dosis de Radiación , Femenino , Estudios de Seguimiento , Humanos , Mácula Lútea/efectos de la radiación , Masculino , Persona de Mediana Edad , Nervio Óptico/efectos de la radiación , Terapia de Protones/efectos adversos , Dosificación Radioterapéutica , Análisis de Regresión , Factores de Tiempo , Resultado del Tratamiento , Trastornos de la Visión/etiología , Trastornos de la Visión/prevención & control , Agudeza Visual/fisiología
11.
Int J Radiat Oncol Biol Phys ; 64(2): 355-62, 2006 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-16256277

RESUMEN

PURPOSE: Many patients with head-and-neck (H&N) cancer have tumor shrinkage and/or weight loss during the course of radiotherapy. We conducted this retrospective study to determine the dosimetric effects of repeat computed tomography (CT) imaging and replanning during the course of intensity-modulated radiotherapy (IMRT) on both normal tissues and target volumes. METHODS AND MATERIALS: A retrospective chart review identified 13 patients with H&N cancer treated with IMRT who had repeat CT imaging and replanning during the course of radiotherapy. The first IMRT plan for each patient was generated based on the original planning CT scan acquired before the start of treatment. Because of tumor shrinkage or weight loss during radiotherapy, a second CT scan was acquired, and a new plan was generated and used to complete the course of IMRT. CT-CT fusion was used to correct patient positioning differences between the scans. By using a commercial inverse IMRT planning system, a hybrid IMRT plan was generated for each patient by applying the beam configurations of the first IMRT plan (including the intensity profile of each beam) to the anatomy of the second CT scan. The dose-volume histograms of the actual and hybrid IMRT plans were compared using analysis of variance methods for repeated measures. RESULTS: All patients had locally advanced, nonmetastatic Stage III or IV disease, including 6 nasopharynx, 6 oropharynx, and 1 unknown primary site. All patients were treated with concurrent platinum-based chemotherapy. When replanning vs. not replanning was compared, the hybrid IMRT plans (without replanning) demonstrated reduced doses to target volumes and increased doses to critical structures. The doses to 95% (D95) of the planning target volumes of the gross tumor volume (PTVGTV) and the clinical target volume (PTVCTV) were reduced in 92% of patients, by 0.8-6.3 Gy (p=0.02) and 0.2-7.4 Gy (p=0.003), respectively. The maximum dose (Dmax) to the spinal cord increased in all patients (range, 0.2-15.4 Gy; p=0.003) and the brainstem Dmax increased in 85% of patients without replanning (range, 0.6-8.1 Gy; p=0.007). CONCLUSIONS: Repeat CT imaging and replanning during the course of IMRT for selected patients with H&N cancer is essential to identify dosimetric changes and to ensure adequate doses to target volumes and safe doses to normal tissues. Future prospective studies with larger sample sizes will help to determine criteria for repeat CT imaging and IMRT replanning for H&N cancer patients undergoing radiotherapy.


Asunto(s)
Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Neoplasias de Cabeza y Cuello/radioterapia , Radioterapia de Intensidad Modulada/métodos , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Tronco Encefálico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Nasofaríngeas/diagnóstico por imagen , Neoplasias Nasofaríngeas/radioterapia , Neoplasias Orofaríngeas/diagnóstico por imagen , Neoplasias Orofaríngeas/radioterapia , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador , Estudios Retrospectivos , Médula Espinal , Estadísticas no Paramétricas , Pérdida de Peso
12.
Int J Radiat Oncol Biol Phys ; 66(1): 152-9, 2006 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-16904520

RESUMEN

PURPOSE: This study sought to review a single-institution experience with the management of adenoid cystic carcinoma of the head and neck. METHODS AND MATERIALS: Between 1960 and 2004, 140 patients with adenoid cystic carcinoma of the head and neck were treated with definitive surgery. Ninety patients (64%) received postoperative radiation to a median dose of 64 Gy (range, 54-71 Gy). Distribution of T stage was: 26% T1, 28% T2, 20% T3, and 26% T4. Seventy-eight patients (56%) had microscopically positive margins. Median follow-up was 66 months (range, 7-267 months). RESULTS: The 5- and 10-year rate estimates of local control were 88% and 77%, respectively. A Cox proportional hazards model identified T4 disease (p = 0.0001), perineural invasion (p = 0.008), omission of postoperative radiation (p = 0.007), and major nerve involvement (p = 0.02) as independent predictors of local recurrence. Radiation dose lower than 60 Gy (p = 0.0004), T4 disease (p = 0.005), and major nerve involvement (p = 0.02) were predictors of local recurrence among those treated with surgery and postoperative radiation. The 10-year overall survival and distant metastasis-free survival were 64% and 66%, respectively. CONCLUSION: Combined-modality therapy with surgery followed by radiation to doses in excess of 60 Gy should be considered the standard of care for adenoid cystic carcinoma of the head and neck.


Asunto(s)
Carcinoma Adenoide Quístico/radioterapia , Carcinoma Adenoide Quístico/cirugía , Neoplasias de Cabeza y Cuello/radioterapia , Neoplasias de Cabeza y Cuello/cirugía , Recurrencia Local de Neoplasia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Adenoide Quístico/secundario , Niño , Terapia Combinada , Supervivencia sin Enfermedad , Femenino , Neoplasias de Cabeza y Cuello/patología , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Modelos de Riesgos Proporcionales , Dosificación Radioterapéutica , Estudios Retrospectivos
13.
J Med Imaging Radiat Oncol ; 60(4): 560-7, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27020481

RESUMEN

INTRODUCTION: Due to complex multimodal treatments and a lengthy natural history of disease, the impact of radiation therapy for well-differentiated thyroid cancer (WDTC) is challenging to evaluate. We analysed the effect of dose escalation, as enabled by intensity-modulated radiation therapy (IMRT), on preventing local-regional failure (LRF) of microscopic and macroscopic WDTC. METHOD: We performed a retrospective review of WDTC patients treated with IMRT from 1998-2011. Diagnostic imaging demonstrating first LRF was registered to the simulation CT containing the treated radiation isodose volumes. Areas of disease progression were contoured and the relationships of LRFs with isodose volumes were recorded. RESULTS: Thirty patients had a median follow-up of 56 months (range = 1-139). Seventeen (57%) had gross residual, five (17%) had microscopic residual and eight (27%) had clear margins at the time of IMRT. Nine patients (30%) developed LRF, at a median time of 44 months (range = 0-116). Of these, six (67%) had been radiated to gross disease and one (11%) had microscopic residual. In the seven analysable cases, only one (14%) LRF occurred within the 70 Gy isodose volume. Marginal LRFs were: four (57%) outside 70 Gy, one (14%) outside 60 Gy and one (14%) outside 50 Gy. All but one recurrence (86%) occurred in the perioesophageal region. CONCLUSIONS: Local-regional failure was seen most in patients who had gross disease at the time of IMRT, almost always occurred outside of the 70 Gy volume and was frequently in the area of oesophageal sparing. Meticulous surgical dissection, especially in the perioesophageal region, should be prioritised to prevent long-term LRF.


Asunto(s)
Recurrencia Local de Neoplasia/epidemiología , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia de Intensidad Modulada/métodos , Neoplasias de la Tiroides/epidemiología , Neoplasias de la Tiroides/radioterapia , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico por imagen , Dosificación Radioterapéutica , Estudios Retrospectivos , Glándula Tiroides/diagnóstico por imagen , Neoplasias de la Tiroides/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Insuficiencia del Tratamiento , Adulto Joven
14.
Radiat Oncol ; 11(1): 127, 2016 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-27671196

RESUMEN

BACKGROUND: There is a lack of data on quality of life in long-term survivors of nasopharyngeal carcinoma (NPC) who have been treated with intensity-modulated radiation therapy (IMRT). We characterized long-term disease-specific and cognitive QoL in NPC survivors after IMRT. METHODS: We conducted a cross-sectional study of surviving patients diagnosed and treated for NPC at our center with curative-intent IMRT, with or without chemotherapy. Patients who were deceased, still undergoing treatment, with known recurrent disease, or treated with RT modality other than IMRT were excluded. QoL was measured by FACT-NP and FACT-Cog. RESULTS: Between May and November 2013, 44 patients completed cognitive (FACT-Cog), general (FACT-G), and NPC-specific (NPCS) QoL assessments. Patients were categorized into 4 cohorts based on duration since IMRT (≤2.5, >2.5-6, >6-10, and >10-16 years). There was no significant difference in age (p = 0.20) or stage ((I/II vs III/IV: p = 0.78) among the cohorts. The 4 cohorts differed overall for all QoL measures (ANOVA: p < 0.02 for each), due to improved scores >2.5-6 years post-IMRT compared with ≤2.5 years post-IMRT (post hoc tests: p ≤ 0.04 for each). No differences were observed between >2.5-6 and >6-10 years post-IMRT, but lower mean FACT-Cog and NPCS scores were observed for >10 years compared to >2.5-6 years post-IMRT (post hoc: p < 0.05 for each). CONCLUSIONS: All QoL measures were low during the initial recovery period (≤2.5 years) and were higher by 6 years post-IMRT. At >10 years post-IMRT, lower scores were observed in the domains of NPC-specific and cognitive QoL. Survivors of NPC, even if treated with IMRT, are at risk for detriment in domain-specific QoL measures at very long-term follow-up.

15.
Int J Radiat Oncol Biol Phys ; 62(3): 925-32, 2005 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-15936579

RESUMEN

PURPOSE: To propose a modified equivalent uniform dose (mEUD) to account for dose fractionation using the biologically effective dose without losing the advantages of the generalized equivalent uniform dose (gEUD) and to report the calculated mEUD and gEUD in clinically used intensity-modulated radiotherapy (IMRT) plans. METHODS AND MATERIALS: The proposed mEUD replaces the dose to each voxel in the gEUD formulation by a biologically effective dose with a normalization factor. We propose to use the term mEUD(D(o))(/n(o)) that includes the total dose (D(o)) and number of fractions (n(o)) and to use the term mEUD(o) that includes the same total dose but a standard fraction size of 2 Gy. A total of 41 IMRT plans for patients with nasopharyngeal cancer treated at our institution between October 1997 and March 2002 were selected for the study. The gEUD and mEUD were calculated for the planning gross tumor volume (pGTV), planning clinical tumor volume (pCTV), parotid glands, and spinal cord. The prescription dose for these patients was 70 Gy to >95% of the pGTV and 59.4 Gy to >95% of the pCTV in 33 fractions. RESULTS: The calculated average gEUD was 72.2 +/- 2.4 Gy for the pGTV, 54.2 +/- 7.1 Gy for the pCTV, 26.7 +/- 4.2 Gy for the parotid glands, and 34.1 +/- 6.8 Gy for the spinal cord. The calculated average mEUD(D(o))(/n(o)) using 33 fractions was 71.7 +/- 3.5 Gy for mEUD(70/33) of the pGTV, 49.9 +/- 7.9 Gy for mEUD(59.5/33) of the pCTV, 27.6 +/- 4.8 Gy for mEUD(26/33) of the parotid glands, and 32.7 +/- 7.8 Gy for mEUD(45/33) of the spinal cord. CONCLUSION: The proposed mEUD, combining the gEUD with the biologically effective dose, preserves all advantages of the gEUD while reflecting the fractionation effects and linear and quadratic survival characteristics.


Asunto(s)
Algoritmos , Fraccionamiento de la Dosis de Radiación , Neoplasias Nasofaríngeas/radioterapia , Radioterapia Conformacional/métodos , Efectividad Biológica Relativa , Humanos , Planificación de la Radioterapia Asistida por Computador/métodos , Terminología como Asunto
16.
Int J Radiat Oncol Biol Phys ; 92(2): 376-83, 2015 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-25841624

RESUMEN

PURPOSE: Relevant clinical data are needed given the increasing national interest in charged particle radiation therapy (CPT) programs. Here we report long-term outcomes from the only randomized, stratified trial comparing CPT with iodine-125 plaque therapy for choroidal and ciliary body melanoma. METHODS AND MATERIALS: From 1985 to 1991, 184 patients met eligibility criteria and were randomized to receive particle (86 patients) or plaque therapy (98 patients). Patients were stratified by tumor diameter, thickness, distance to disc/fovea, anterior extension, and visual acuity. Tumors close to the optic disc were included. Local tumor control, as well as eye preservation, metastases due to melanoma, and survival were evaluated. RESULTS: Median follow-up times for particle and plaque arm patients were 14.6 years and 12.3 years, respectively (P=.22), and for those alive at last follow-up, 18.5 and 16.5 years, respectively (P=.81). Local control (LC) for particle versus plaque treatment was 100% versus 84% at 5 years, and 98% versus 79% at 12 years, respectively (log rank: P=.0006). If patients with tumors close to the disc (<2 mm) were excluded, CPT still resulted in significantly improved LC: 100% versus 90% at 5 years and 98% versus 86% at 12 years, respectively (log rank: P=.048). Enucleation rate was lower after CPT: 11% versus 22% at 5 years and 17% versus 37% at 12 years, respectively (log rank: P=.01). Using Cox regression model, likelihood ratio test, treatment was the most important predictor of LC (P=.0002) and eye preservation (P=.01). CPT was a significant predictor of prolonged disease-free survival (log rank: P=.001). CONCLUSIONS: Particle therapy resulted in significantly improved local control, eye preservation, and disease-free survival as confirmed by long-term outcomes from the only randomized study available to date comparing radiation modalities in choroidal and ciliary body melanoma.


Asunto(s)
Neoplasias de la Coroides/radioterapia , Cuerpo Ciliar , Helio/uso terapéutico , Radioisótopos de Yodo/uso terapéutico , Melanoma/radioterapia , Neoplasias de la Úvea/radioterapia , Adulto , Anciano , Anciano de 80 o más Años , Braquiterapia/métodos , Neoplasias de la Coroides/mortalidad , Neoplasias de la Coroides/patología , Cuerpo Ciliar/patología , Supervivencia sin Enfermedad , Enucleación del Ojo/estadística & datos numéricos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Melanoma/mortalidad , Melanoma/patología , Persona de Mediana Edad , Tratamientos Conservadores del Órgano , Dosificación Radioterapéutica , Factores de Tiempo , Neoplasias de la Úvea/mortalidad , Neoplasias de la Úvea/patología , Adulto Joven
17.
Int J Radiat Oncol Biol Phys ; 56(2): 544-55, 2003 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-12738332

RESUMEN

PURPOSE: This article presents the American Brachytherapy Society (ABS) guidelines for the use of brachytherapy for patients with choroidal melanomas. METHODS: Members of the ABS with expertise in choroidal melanoma formulated brachytherapy guidelines based upon their clinical experience and a review of the literature. The Board of Directors of the ABS approved the final report. RESULTS: Episcleral plaque brachytherapy is a complex procedure and should only be undertaken in specialized medical centers with expertise in this sophisticated treatment program. Recommendations were made for patient selection, techniques, dose rates, and dosages. Most patients with very small uveal melanomas (<2.5 mm height and <10 mm in largest basal dimension) should be observed for tumor growth before treatment. Patients with a clinical diagnosis of medium-sized choroidal melanoma (between 2.5 and 10 mm in height and <16 mm basal diameter) are candidates for episcleral plaques if the patient is otherwise healthy and without metastatic disease. A histopathologic verification is not required. Small melanomas may be candidates if there is documented growth; some patients with large melanomas (>10 mm height or >16 mm basal diameter) may also be candidates. Patients with large tumors or with tumors at peripapillary and macular locations have a poorer visual outcome and lower local control that must be taken into account in the patient decision-making process. Patients with gross extrascleral extension, ring melanoma, and tumor involvement of more than half of the ciliary body are not suitable for plaque therapy. For plaque fabrication, the ophthalmologist must provide the tumor size (including basal diameters and tumor height) and a detailed fundus diagram. The ABS recommends a minimum tumor (125)I dose of 85 Gy at a dose rate of 0.60-1.05 Gy/h using AAPM TG-43 formalism for the calculation of dose. NRC or state licensing guidelines regarding procedures for handling of radioisotopes must be followed. CONCLUSIONS: Brachytherapy represents an effective means of treating patients with choroidal melanomas. Guidelines are established for the use of brachytherapy in the treatment of choroidal melanomas. Practitioners and cooperative groups are encouraged to use these guidelines to formulate their treatment and dose reporting policies. These guidelines will be modified as further clinical results become available.


Asunto(s)
Braquiterapia/normas , Melanoma/radioterapia , Neoplasias de la Úvea/radioterapia , Neoplasias de la Coroides/patología , Neoplasias de la Coroides/radioterapia , Neoplasias de la Coroides/cirugía , Enucleación del Ojo , Predicción , Humanos , Radioisótopos de Yodo/uso terapéutico , Melanoma/patología , Melanoma/cirugía , Paladio/uso terapéutico , Radioisótopos/uso terapéutico , Dosificación Radioterapéutica , Radioisótopos de Rutenio/uso terapéutico , Neoplasias de la Úvea/patología , Neoplasias de la Úvea/cirugía
18.
Int J Radiat Oncol Biol Phys ; 59(2): 584-94, 2004 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-15145180

RESUMEN

PURPOSE: To describe in detail a forward-planned multisegment technique (FPMS) as an alternative treatment method for patients who are not suitable for inverse-planned intensity-modulated radiation therapy (IP-IMRT), or for situations where IP-IMRT is not available in a medical clinic. METHODS AND MATERIALS: Between April 1995 and February 2002, 38 primary head-and-neck patients were treated using the FPMS technique, which has evolved over the past 7 years at our medical center. In the most recent version of the FPMS technique, which includes 5 patients examined in this analysis, the primary tumor and the upper neck nodes were treated with 7 gantry angles, including an anterior, 2 lateral, 2 anterior oblique, and 2 posterior oblique beams with a total of 13 beam shapes formed by multileaf collimators (MLC), called MLC segments. The shape of each MLC segment was carefully designed, and the associated weights were optimized through manual iterations. The lower neck nodes and the supraclavicular nodes were treated with a split-beam anterior field, matched to the inferior border of the FPMS plan at the isocenter. With an autosequencing delivery system, all fields, including dynamic wedges, can be automatically treated. The dosimetric accuracy of this technique was verified with a phantom plan and measured with an ionization chamber, as well as film dosimetry. A sample FPMS plan is described in detail, and the average results for the 5 patients treated with FPMS are retrospectively compared to results for similar patients treated with IP-IMRT. RESULTS: The gross tumor volume was prescribed to 70 Gy (2.12 Gy/fraction) at the 88% isodose line, whereas the clinical target volume received a dose of 59.4 Gy (1.8 Gy/fraction) at the 75% isodose line. The maximum dose to the brainstem and spinal cord was below 54 and 45 Gy, respectively, comparable to IP-IMRT. The mean dose to the parotid glands was 32 Gy with FPMS vs. 26 Gy with IP-IMRT. Average delivery time was shorter for FPMS (15 min) than IP-IMRT (30 min), whereas the planning time depended on the expertise of the planner. Dosimetric accuracy for FPMS and IP-IMRT plans using phantom measurements was similar, within 1% of the phantom plan. With a median follow-up of 31 months, there was no local-regional recurrence, and the incidence of xerostomia is reduced compared to conventional techniques. CONCLUSION: FPMS achieved plans comparable to those for IP-IMRT and is an ideal alternative treatment technique for a center without the capabilities of IP-IMRT or for a patient who is not a suitable candidate, because of prolonged treatment time. The treatment outcomes from our clinical experience indicate that FPMS can achieve excellent local freedom from progression rates without causing excessive toxicity. Lastly, IP-IMRT plans should be comparable to, if not better than, FPMS plans in the treatment of head-and-neck cancer.


Asunto(s)
Neoplasias de Cabeza y Cuello/radioterapia , Tronco Encefálico , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Humanos , Irradiación Linfática/métodos , Fantasmas de Imagen , Radiografía , Radioterapia/métodos , Dosificación Radioterapéutica , Estudios Retrospectivos , Médula Espinal
19.
Int J Radiat Oncol Biol Phys ; 57(1): 49-60, 2003 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-12909215

RESUMEN

PURPOSE: To review the University of California-San Francisco (UCSF) experience of using intensity-modulated radiation therapy (IMRT) to treat head-and-neck cancer focusing on the importance of target volume delineation and adequate target volume coverage. METHODS AND MATERIALS: Between April 1995 and January 2002, 150 histologically confirmed patients underwent IMRT for their head-and-neck cancer at our institution. Sites included were nasopharynx 86, oropharynx 22, paranasal sinus 22, thyroid 6, oral tongue 3, nasal cavity 2, salivary 2, larynx 2, hypopharynx 1, lacrimal gland 1, skin 1, temporal bone 1, and trachea 1. One hundred seven patients were treated definitively with IMRT +/- concurrent platinum chemotherapy (92/107), whereas 43 patients underwent gross surgical resection followed by postoperative IMRT +/- concurrent platinum chemotherapy (15/43). IMRT was delivered using three different techniques: 1) manually cut partial transmission blocks, 2) computer-controlled auto-sequencing segmental multileaf collimator, and 3) sequential tomotherapy using dynamic multivane intensity-modulating collimator. Forty-two patients were treated with a forward plan, 102 patients with an inverse plan, and 6 patients with both forward and inverse plans. The gross target volume (GTV) was defined as tumor detected on physical examination or imaging studies. In postoperative cases, the GTV was defined as the preoperative gross tumor volume. The clinical target volume (CTV) included all potential areas at risk for microscopic tumor involvement by either direct extension or nodal spread including a margin for patient motion and setup errors. The average prescription doses to the GTV were 70 Gy and 66 Gy for the primary and the postoperative cases, respectively. The site of recurrence was determined by the diagnostic neuroradiologist to be either within the GTV or the CTV volume by comparison of the treatment planning computed tomography with posttreatment imaging studies. RESULTS: For the primary definitive cases with a median follow-up of 25 months (range 6 to 78 months), 4 patients failed in the GTV. The 2- and 3-year local freedom from progression (LFFP) rates were 97% and 95%. With a median follow-up of 17 months (range 8 to 56 months), 7 patients failed in the postoperative setting. The 2-year LFFP rate was 83%. For the primary group, the average maximum, mean, and minimum doses delivered were 80 Gy, 74 Gy, 56 Gy to the GTV, and 80 Gy, 69 Gy, 33 Gy to the CTV. An average of only 3% of the GTV and 3% of the CTV received less than 95% of the prescribed dose. For the postoperative group, the average maximum, mean, and minimum doses delivered were 79 Gy, 71 Gy, 37 Gy to the GTV and 79 Gy, 66 Gy, 21 Gy to the CTV. An average of only 6% of the GTV and 6% of the CTV received less than 95% of the prescribed dose. CONCLUSION: Accurate target volume delineation in IMRT treatment for head-and-neck cancer is essential. Our multidisciplinary approach in target volume definition resulted in few recurrences with excellent LFFP rates and no marginal failures. Higher treatment failure rates were noted in the postoperative setting in which lower doses were prescribed. Potential dose escalation studies may further improve the local control rates in the postoperative setting.


Asunto(s)
Neoplasias de Cabeza y Cuello/epidemiología , Neoplasias de Cabeza y Cuello/radioterapia , Imagenología Tridimensional/métodos , Recurrencia Local de Neoplasia/epidemiología , Planificación de la Radioterapia Asistida por Computador/métodos , Centros Médicos Académicos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , California/epidemiología , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias/métodos , Radiografía , Radioterapia Conformacional/métodos , Análisis de Supervivencia , Resultado del Tratamiento
20.
Int J Radiat Oncol Biol Phys ; 53(1): 12-22, 2002 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-12007936

RESUMEN

PURPOSE: To update our experience with intensity-modulated radiotherapy (IMRT) in the treatment of nasopharyngeal carcinoma (NPC). METHODS AND MATERIALS: Between April 1995 and October 2000, 67 patients underwent IMRT for NPC at the University of California-San Francisco (UCSF). There were 20 females and 47 males, with a mean age of 49 (range 17-82). The disease was Stage I in 8 (12%), Stage II in 12 (18%), Stage III in 22 (33%), and Stage IV in 25 (37%). IMRT was delivered using three different techniques: 1) manually cut partial transmission blocks, 2) computer-controlled auto-sequencing segmental multileaf collimator (SMLC), and 3) sequential tomotherapy using a dynamic multivane intensity modulating collimator (MIMiC). Fifty patients received concomitant cisplatinum and adjuvant cisplatinum and 5-FU chemotherapy according to the Intergroup 0099 trial. Twenty-six patients had fractionated high-dose-rate intracavitary brachytherapy boost and 1 patient had gamma knife radiosurgery boost after external beam radiotherapy. The prescribed dose was 65-70 Gy to the gross tumor volume (GTV) and positive neck nodes, 60 Gy to the clinical target volume (CTV), 50-60 Gy to the clinically negative neck, and 5-7 Gy in 2 fractions for the intracavitary brachytherapy boost. Acute and late normal tissue effects were graded according to the Radiation Therapy Oncology Group (RTOG) radiation morbidity scoring criteria. The local progression-free, local-regional progression-free, distant metastasis-free rates, and the overall survival were calculated using the Kaplan-Meier method. RESULTS: With a median follow-up of 31 months (range 7 to 72 months), there has been one local recurrence at the primary site. One patient failed in the neck. Seventeen patients developed distant metastases; 5 of these patients have died. The 4-year estimates of local progression-free, local-regional progression-free, and distant metastases-free rates were 97%, 98%, and 66% respectively. The 4-year estimate of overall survival was 88%. The worst acute toxicity documented was as follows: Grade 1 or 2 in 51 patients, Grade 3 in 15 patients, and Grade 4 in 1 patient. The worst late toxicity was Grade 1 in 20 patients, Grade 2 in 15 patients, Grade 3 in 7 patients, and Grade 4 in 1 patient. At 3 months after IMRT, 64% of the patients had Grade 2, 28% had Grade 1, and 8% had Grade 0 xerostomia. Xerostomia decreased with time. At 24 months, only one of the 41 evaluable patients had Grade 2, 32% had Grade 1, and 66% had Grade 0 or no xerostomia. Analysis of the dose-volume histograms (DVHs) showed that the average maximum, mean, and minimum dose delivered were 79.3 Gy, 74.5 Gy, and 49.4 Gy to the GTV, and 78.9 Gy, 68.7 Gy, and 36.8 Gy to the CTV. An average of only 3% of the GTV and 3% of the CTV received less than 95% of the prescribed dose. CONCLUSION: Excellent local-regional control for NPC was achieved with IMRT. IMRT provided excellent tumor target coverage and allowed the delivery of a high dose to the target with significant sparing of the salivary glands and other nearby critical normal tissues.


Asunto(s)
Neoplasias Nasofaríngeas/radioterapia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Nasofaríngeas/patología , Estadificación de Neoplasias , Dosificación Radioterapéutica , Resultado del Tratamiento
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