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1.
Pract Radiat Oncol ; 11(3): 177-184, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33640315

RESUMEN

PURPOSE: Radiation treatment planning for head and neck cancer is a complex process with much variability; automated treatment planning is a promising option to improve plan quality and efficiency. This study compared radiation plans generated from a fully automated radiation treatment planning system to plans generated manually that had been clinically approved and delivered. METHODS AND MATERIALS: The study cohort consisted of 50 patients treated by a specialized head and neck cancer team at a tertiary care center. An automated radiation treatment planning system, the Radiation Planning Assistant, was used to create autoplans for all patients using their original, approved contours. Common dose-volume histogram (DVH) criteria were used to compare the quality of autoplans to the clinical plans. Fourteen radiation oncologists, each from a different institution, then reviewed and compared the autoplans and clinical plans in a blinded fashion. RESULTS: Autoplans and clinical plans were very similar with regard to DVH metrics for coverage and critical structure constraints. Physician reviewers found both the clinical plans and autoplans acceptable for use; overall, 78% of the clinical plans and 88% of the autoplans were found to be usable as is (without any edits). When asked to choose which plan would be preferred for approval, 27% of physician reviewers selected the clinical plan, 47% selected the autoplan, 25% said both were equivalent, and 0% said neither. Hence, overall, 72% of physician reviewers believed the autoplan or either the clinical or autoplan was preferable. CONCLUSIONS: Automated radiation treatment planning creates consistent, clinically acceptable treatment plans that meet DVH criteria and are found to be appropriate on physician review.


Asunto(s)
Neoplasias de Cabeza y Cuello , Planificación de la Radioterapia Asistida por Computador , Radioterapia de Intensidad Modulada , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Neoplasias de Cabeza y Cuello/radioterapia , Humanos , Órganos en Riesgo , Dosificación Radioterapéutica
2.
OTO Open ; 4(3): 2473974X20938313, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32671318

RESUMEN

By 2030, 70% of cancers will occur in developing countries. Head and neck cancers are primarily a developing world disease. While anatomical location and the extent of cancers are central to defining prognosis and staging, the American Joint Committee on Cancer (AJCC)/International Union Against Cancer (UICC) have incorporated nonanatomic factors that correlate with prognosis into staging (eg, p16 status of oropharyngeal cancers). However, 16 of 17 head and neck surgeons from 13 African countries cannot routinely test for p16 status and hence can no longer apply AJCC/UICC staging to oropharyngeal cancer. While the AJCC/UICC should continue to refine staging that best reflects treatment outcomes and prognosis by incorporating new nonanatomical factors, they should also retain and refine anatomically based staging to serve the needs of clinicians and their patients in resource-constrained settings. Not to do so would diminish their global relevance and in so doing also disadvantage most of the world's cancer patients.

3.
J Glob Oncol ; 4: 1-11, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-30110221

RESUMEN

Purpose We assessed automated contouring of normal structures for patients with head-and-neck cancer (HNC) using a multiatlas deformable-image-registration algorithm to better provide a fully automated radiation treatment planning solution for low- and middle-income countries, provide quantitative analysis, and determine acceptability worldwide. Methods Autocontours of eight normal structures (brain, brainstem, cochleae, eyes, lungs, mandible, parotid glands, and spinal cord) from 128 patients with HNC were retrospectively scored by a dedicated HNC radiation oncologist. Contours from a 10-patient subset were evaluated by five additional radiation oncologists from international partner institutions, and interphysician variability was assessed. Quantitative agreement of autocontours with independently physician-drawn structures was assessed using the Dice similarity coefficient and mean surface and Hausdorff distances. Automated contouring was then implemented clinically and has been used for 166 patients, and contours were quantitatively compared with the physician-edited autocontours using the same metrics. Results Retrospectively, 87% of normal structure contours were rated as acceptable for use in dose-volume-histogram-based planning without edit. Upon clinical implementation, 50% of contours were not edited for use in treatment planning. The mean (± standard deviation) Dice similarity coefficient of autocontours compared with physician-edited autocontours for parotid glands (0.92 ± 0.10), brainstem (0.95 ± 0.09), and spinal cord (0.92 ± 0.12) indicate that only minor edits were performed. The average mean surface and Hausdorff distances for all structures were less than 0.15 mm and 1.8 mm, respectively. Conclusion Automated contouring of normal structures generates reliable contours that require only minimal editing, as judged by retrospective ratings from multiple international centers and clinical integration. Autocontours are acceptable for treatment planning with no or, at most, minor edits, suggesting that automated contouring is feasible for clinical use and in the ongoing development of automated radiation treatment planning algorithms.


Asunto(s)
Neoplasias de Cabeza y Cuello/radioterapia , Cabeza/anatomía & histología , Cuello/anatomía & histología , Pobreza/tendencias , Anciano , Femenino , Neoplasias de Cabeza y Cuello/patología , Humanos , Masculino , Órganos en Riesgo , Estudios Retrospectivos
4.
Br J Ophthalmol ; 99(9): 1158-61, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25784215

RESUMEN

BACKGROUND: This study explores the safety and efficacy of strontium 90 (Sr-90) brachytherapy as the sole adjuvant therapy for carcinoma in situ (CIS) and squamous cell carcinoma (SCC) of the conjunctiva in a high HIV prevalent area. METHODS: This is a retrospective case review of patients treated with 60 Gray Sr-90 brachytherapy in four divided doses after resection with a 2 mm margin and histological confirmation. Cryotherapy or alcohol debridement was not performed at the time of excision due to limited resources. Two plaque sizes, 8.5 mm and 18 mm, were used. RESULTS: Sixty-nine patients were treated and had a median follow-up of 27 months (range 6-127). Thirty-three (47.8%) were HIV-positive. CIS was present in 40.6% and SCC in 59.4%. The surgical margins were positive in 39 (56.5%). Twenty patients (29.0%) were treated with the 18 mm plaque and 49 (71.0%) with the 8.5 mm plaque. Eight (11.6%) patients developed a recurrence at a median of 5 months (range 2-40). Recurrences only occurred in patients treated with the 8.5 mm plaque (p=0.094). There was no significant effect of HIV status, positive margins or staging on the number of recurrences. Treatment side effects were a dry eye in five patients which was successfully managed with topical lubricants, and induced astigmatism of 1 dioptre of cylinder in one patient. CONCLUSIONS: Sr-90 brachytherapy is safe and effective in preventing recurrences in ocular surface squamous neoplasia in a high HIV prevalent setting. The 18 mm plaque size is superior to the 8.5 mm plaque size.


Asunto(s)
Braquiterapia/métodos , Carcinoma in Situ/radioterapia , Carcinoma de Células Escamosas/radioterapia , Neoplasias de la Conjuntiva/radioterapia , Infecciones por VIH , Radioisótopos de Estroncio/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma in Situ/cirugía , Carcinoma de Células Escamosas/cirugía , Terapia Combinada , Neoplasias de la Conjuntiva/cirugía , Fraccionamiento de la Dosis de Radiación , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Estudios Retrospectivos , Adulto Joven
5.
Brachytherapy ; 13(4): 405-12, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24818781

RESUMEN

PURPOSE: Brachytherapy is an acknowledged modality for treating head and neck cancers and has moved from low-dose-rate (LDR) to high-dose-rate remote afterloading to reduce staff exposure. Iodine-125 ((125)I) is a low-energy source and can be used for LDR brachytherapy with minimal staff exposure. The results of treating with this isotope at Groote Schuur Hospital, Cape Town, are reported here. METHODS AND MATERIALS: (125)I brachytherapy was used to treat 114 tumors from 1994 to 2010. Brachytherapy alone was used for 72 tumors, 39 postsurgery and 33 de novo. A brachytherapy boost together with external beam radiotherapy was used for 42 tumors, eight postsurgery and 34 de novo. Tumors were in the tongue, floor of mouth, soft palate, and tonsil, and mainly T1 or T2 classification. Brachytherapy was administered via an applicator or in plastic tubes implanted into the soft tissues or through the submandibular region. RESULTS: Local control rates of 80.7% at 5 years and 80% at 10 years were comparable to LDR, pulsed-dose-rate, and high-dose-rate results with iridium-192, likewise the 5- and 10-year disease-specific survival rate of 74.3%. Complications of soft tissue ulceration occurred in 21 patients (18.4%) and healed spontaneously in 20 patients. There was no mandibular necrosis. CONCLUSIONS: (125)I can be used as the sole treatment or as a boost to external beam radiotherapy, with or without surgery for early mouth cancer. It combines the radiobiological advantages of LDR brachytherapy with minimum staff exposure. It is a flexible system. Local control is excellent with acceptable morbidity, and the treatment time is short.


Asunto(s)
Braquiterapia/métodos , Carcinoma de Células Escamosas/radioterapia , Neoplasias de la Boca/radioterapia , Neoplasias Orofaríngeas/radioterapia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Braquiterapia/efectos adversos , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/cirugía , Niño , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Radioisótopos de Yodo/uso terapéutico , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/mortalidad , Neoplasias de la Boca/cirugía , Neoplasias Orofaríngeas/mortalidad , Neoplasias Orofaríngeas/cirugía , Radiofármacos/uso terapéutico , Radioterapia Adyuvante , Estudios Retrospectivos , Tasa de Supervivencia , Resultado del Tratamiento , Adulto Joven
6.
Artículo en Inglés | MEDLINE | ID: mdl-22668708

RESUMEN

OBJECTIVES: The aim of this study was to evaluate a cost-effective oral liquid-based cytology screening test, Shandon Papspin (PS). STUDY DESIGN: We compared the diagnostic accuracy of PS with surgical biopsy in 69 patients. Transepithelial cytology specimens were obtained with the use of cervical cytobrushes. Cytology specimens were graded and scored by using a novel oral cytologic grading and scoring system. RESULTS: Histologic diagnosis of dysplasia or malignancy was made in 51/69 cases, and cytology identified 49/51 cases, with a sensitivity of 96% and specificity of 100%. The best cutoff value for distinguishing reactive/mildly dysplastic lesions from high grade/invasive squamous cell carcinoma was determined to be a cytologic score of 3, representing a sensitivity of 95% and specificity of 96%. CONCLUSIONS: PS appears to be an accurate and economical test for detection of high-risk dysplasias and cancers, but the real significance of this method will be its diagnostic accuracy in studies focusing strictly on lesions with a low level of clinical concern.


Asunto(s)
Carcinoma de Células Escamosas/patología , Centrifugación , Citodiagnóstico/métodos , Células Epiteliales/patología , Indicadores y Reactivos , Mucosa Bucal/patología , Neoplasias de la Boca/patología , Biopsia/métodos , Análisis Costo-Beneficio , Citodiagnóstico/instrumentación , Humanos , Tamizaje Masivo/métodos , Clasificación del Tumor/métodos , Neoplasias Orofaríngeas/patología , Sensibilidad y Especificidad
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