Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
1.
Pract Radiat Oncol ; 14(2): e117-e131, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37661040

RESUMO

Traditionally, external beam radiotherapy (EBRT) for localized prostate cancer (PCa) involved lengthy courses with low daily doses. However, advancements in radiation delivery and a better understanding of prostate radiobiology have enabled the development of shorter courses of EBRT. Ultrahypofractionated radiotherapy, administering doses greater than 5 Gy per fraction, is now considered a standard of care regimen for localized PCa, particularly for intermediate-risk disease. Stereotactic body radiotherapy (SBRT), a specific type of ultrahypofractionated radiotherapy employing advanced planning, imaging, and treatment technology to deliver in five or fewer fractions, is gaining prominence as a cost-effective, convenient, and safe alternative to longer radiotherapy courses. It is crucial to address practical considerations related to patient selection, fractionation scheme, target delineation, and planning objectives. This is especially important in challenging clinical situations where clear evidence for guidance may be lacking. The Radiosurgery Society endorses this case-based guide with the aim of providing a practical framework for delivering SBRT to the intact prostate, exemplified by two case studies. The article will explore common SBRT dose/fractionation schemes and dose constraints for organs-at-risk. Additionally, it will review existing evidence and expert opinions on topics such as SBRT dose escalation, the use of rectal spacers, the role of androgen deprivation therapy in the context of SBRT, SBRT in special patient populations (e.g., high-risk disease, large prostate, high baseline urinary symptom burdens, and inflammatory bowel disease), as well as new imaging-guidance techniques like Magnetic Resonance Imaging for SBRT delivery.


Assuntos
Neoplasias da Próstata , Radioterapia (Especialidade) , Radiocirurgia , Masculino , Humanos , Neoplasias da Próstata/radioterapia , Antagonistas de Androgênios , Próstata
2.
J Racial Ethn Health Disparities ; 10(2): 501-508, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35064522

RESUMO

PURPOSE: Reduced access and utilization of radiation therapy (RT) is a well-documented healthcare disparity observed among racial and ethnic minority groups in the USA and a contributor to the inferior health outcomes observed among Black, Hispanic, and Native American patient groups. What is less understood are the points during the process of care following RT consultation at which patients either fail to complete their prescribed treatment or encounter delays. Identification of those points where significant differences exist among different patient groups may help identify opportunities to close gaps in the access of clinically indicated RT. METHODS AND MATERIALS: This analysis examines 261,559 RT episodes abstracted from Medicare claims and beneficiary data between 2016 and 2018 to determine rates of treatment initiation following planning and timeliness of treatment completion for different racial groups. RESULTS: Failure to initiate treatment was observed to be 29.3% relatively greater for Black, Hispanic, and Native American patients than for White and Asian patients. Among episodes for which treatment was initiated, Black and Hispanic patients were observed to require a significantly greater number of calendar days (when adjusted for fraction number) for completion than for White, Asian, and Native American patients. CONCLUSIONS: There appears to be a patient cohort for which RT disparities may be more marginal in their effects-allowing for access to consultation and treatment prescription but not for treatment initiation or timely completion of treatment-and may therefore permit effective solutions to help address current differences in cancer outcomes.


Assuntos
Etnicidade , Medicare , Humanos , Idoso , Estados Unidos , Revisão da Utilização de Seguros , Grupos Minoritários , Grupos Raciais
3.
J Am Coll Radiol ; 19(1 Pt A): 53-60, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34762833

RESUMO

Radiation oncology reimbursement methodology has been largely unchanged over the past 30 years, and new approaches are of great interest to practicing radiation oncologists and other health care stakeholders. Traditional radiation oncology reimbursement is based on a series of individual codes for evaluation and management (professional) and technical services, yielding a complex reimbursement system. In an attempt to move toward a simpler, episodic payment model, bundling all of the codes into a single payment, an alternative payment model for radiation oncology was developed. The radiation oncology alternative payment model is a revolutionary change in how radiation oncologic services will be reimbursed and has potential to affect all aspects of radiation oncologic care. Here, the authors review the origin of the currently proposed radiation oncology model and discuss potential implications of this model on the provision of care, especially as it relates to rural practices and other underserved and vulnerable patient populations.


Assuntos
Radioterapia (Especialidade) , Atenção à Saúde , Humanos , Oncologia , Mecanismo de Reembolso , Estados Unidos , Populações Vulneráveis
4.
JCO Oncol Pract ; 17(12): 777-781, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34524836

RESUMO

In its current form, the Radiation Oncology Model (RO Model) prioritizes payment cuts over true value-based payment transformation. With significant modifications to the payment methodology, the reporting requirements, and recognition of the unique challenges faced by disadvantaged populations, the RO Model can protect patient access to care, preserve the physician-patient decision-making process, and ensure the delivery of high-quality, efficient radiation therapy treatment. The American Society for Radiation Oncology has spent several years advocating for a meaningful alternative payment model for radiation oncology and continues to push The Center for Medicare and Medicaid Innovation for changes to the RO Model that will recognize these key outcomes.


Assuntos
Medicare , Radioterapia (Especialidade) , Idoso , Humanos , Medicaid , Estados Unidos
5.
J Sex Med ; 6(4): 1135-1140, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19210713

RESUMO

INTRODUCTION: Phosphodiesterase type 5 inhibitor (PDE5) use is a treatment strategy for prostate cancer patients with post-radiation therapy (RT) erectile dysfunction (ED). AIM: To define the predictors of sildenafil response in men treated with RT for prostate cancer. MAIN OUTCOME MEASURES: International Index of Erectile Function (IIEF). METHODS: Patients were enrolled prospectively if they met the following criteria: (i) either a three-dimensional conformal external beam (EBRT) or brachytherapy (BT) with or without androgen deprivation (AD) for prostate cancer; (ii) self-reported ability to have sexual intercourse prior to RT; (iii) experienced onset of ED following RT; (iv) candidates for sildenafil citrate use; (v) followed-up periodically; and (vi) completed the IIEF at least 12 months after RT. Failure to respond to sildenafil was defined as IIEF-erectile function (EF) domain score of <22. RESULTS: One hundred fifty-two patients met all the criteria: 110 in the EBRT group and 42 in the BT group. Mean age was 62 years. The mean follow-up was 38 months. Mean radiation dose for EBRT was 78 Gy and for BT was 101 Gy. Thirty-five patients received AD, 25% of EBRT, and 62% of BT patients. Sixty-one percent of the patients receiving AD had exposure only pre-RT, whereas 39% had pre- and post-RT AD exposure. The mean duration of AD was 4.6 months. Post-RT IIEF-EF domain score at >24 months was 17. Successful response to sildenafil occurred in 68% of men at 12 months after RT, 50% at 24 months, and 36% at 36 months. On multivariable analysis, predictors of failure to respond to sildenafil were: older age, longer time after RT, AD > 4 months duration, and RT dose > 85 Gy. Modality of radiation delivery was not predictive of sildenafil failure. CONCLUSIONS: A steady decrease in sildenafil response was seen with increasing duration after RT. Several factors were predictive of sildenafil failure.


Assuntos
Disfunção Erétil/tratamento farmacológico , Disfunção Erétil/etiologia , Inibidores da Fosfodiesterase 5 , Inibidores de Fosfodiesterase/uso terapêutico , Piperazinas/uso terapêutico , Neoplasias da Próstata/complicações , Neoplasias da Próstata/radioterapia , Sulfonas/uso terapêutico , Relação Dose-Resposta à Radiação , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Purinas/uso terapêutico , Dosagem Radioterapêutica , Índice de Gravidade de Doença , Citrato de Sildenafila , Fatores de Tempo
6.
Int J Radiat Oncol Biol Phys ; 102(2): 296-303, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30191864

RESUMO

PURPOSE: The radiobiology of prostate cancer may favor the extreme hypofractionation inherent in stereotactic body radiation therapy (SBRT); however, data from a large multicenter study are lacking. We therefore examined the hypothesis that dose-escalated SBRT can be safely administered across multiple institutions, with favorable 5-year disease-free survival (DFS) rates compared with historical controls. METHODS AND MATERIALS: Twenty-one centers enrolled 309 patients with prostate adenocarcinoma: 172 with low-risk (LR) and 137 with intermediate-risk (IR) disease. All were treated with a non-coplanar robotic SBRT platform using real-time tracking of implanted fiducials. The prostate was prescribed 40 Gy in 5 fractions of 8 Gy. We assessed toxicities using Common Terminology Criteria for Adverse Events (CTCAE) version 3 and biochemical failure using the "nadir + 2" definition. The study population yielded 90% power to identify excessive (>10%) rates of grade ≥3 genitourinary (GU) or gastrointestinal toxicities and, in the LR group, 80% power to show superiority in DFS over a 93% historical comparison rate. RESULTS: At a median follow-up of 61 months, 2 LR patients (1.2%) and 2 IR patients (1.5%) experienced grade 3 GU toxicities, far below the 10% toxicity rate deemed excessive (upper limits of 95% confidence interval, 3.5% and 4.3%, respectively). No grade 4 or 5 toxicities occurred. All grade 3 toxicities were GU, occurring 11 to 51 months after treatment. For the entire group, the actuarial 5-year overall survival rate was 95.6% and the DFS rate was 97.1%. The 5-year DFS rate was 97.3% for LR patients (superior to the 93% DFS rate for historical controls; P = .0008; lower limit of 95% confidence interval, 94.6%) and 97.1% for IR patients. CONCLUSIONS: Dose-escalated prostate SBRT was administered with minimal toxicity in this multi-institutional study. Relapse rates compared favorably with historical controls. SBRT is a suitable option for LR and IR prostate cancer.


Assuntos
Adenocarcinoma/mortalidade , Adenocarcinoma/radioterapia , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/radioterapia , Radiocirurgia/efeitos adversos , Radiocirurgia/mortalidade , Adenocarcinoma/sangue , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Humanos , Masculino , Pessoa de Meia-Idade , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Neoplasias da Próstata/patologia , Radiocirurgia/métodos , Dosagem Radioterapêutica , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Procedimentos Cirúrgicos Robóticos/métodos , Procedimentos Cirúrgicos Robóticos/mortalidade
7.
Int J Radiat Oncol Biol Phys ; 67(3): 834-40, 2007 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-17293236

RESUMO

PURPOSE: To evaluate the long-term failure patterns in patients who underwent an (111)In-capromab pendetide (ProstaScint) scan as part of their pretreatment assessment for a rising prostate-specific antigen (PSA) level after prostatectomy and subsequently received local radiotherapy (RT) to the prostate bed. METHODS: Fifty-eight patients were referred for evaluation of a rising PSA level after radical prostatectomy. All patients had negative findings for metastatic disease after abdominal/pelvis imaging with CT and isotope bone scans. All patients underwent a capromab pendetide scan, and the sites of uptake were noted. All patients were treated with local prostate bed RT (median dose 66.6 Gy). RESULTS: Of the 58 patients, 20 had biochemical failure (post-RT PSA level >0.2 ng/mL or a rise to greater than the nadir PSA), including 6 patients with positive uptake outside the bed (positive elsewhere). The 4-year biochemical relapse-free survival (bRFS) rates for patients with negative (53%), positive in the prostate bed alone (45%), or positive elsewhere (74%) scan findings did not differ significantly (p = 0.51). The positive predictive value of the capromab pendetide scan in detecting disease outside the bed was 27%. The capromab pendetide scan status had no effect on bRFS. Those with a pre-RT PSA level of <1 ng/mL had improved bRFS (p = 0.003). CONCLUSION: The capromab pendetide scan has a low positive predictive value in patients with positive elsewhere uptake and the 4-year bRFS was similar to that for those who did not exhibit positive elsewhere uptake. Therefore, patients with a postprostatectomy rising PSA level should considered for local RT on the basis of clinicopathologic factors.


Assuntos
Anticorpos Monoclonais , Indicadores e Reagentes , Radioisótopos de Índio , Recidiva Local de Neoplasia/diagnóstico por imagem , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/sangue , Recidiva Local de Neoplasia/radioterapia , Prostatectomia , Neoplasias da Próstata/sangue , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/cirurgia , Cintilografia , Estudos Retrospectivos , Terapia de Salvação
8.
J Urol ; 178(6): 2521-5, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17937948

RESUMO

PURPOSE: Radiation therapy is a widely accepted strategy for prostate cancer. Erectile dysfunction is a common complication of radiation therapy. Adjuvant androgen deprivation was shown to prolong survival in select patients. There is controversy regarding the impact of androgen deprivation on erectile function. We defined the impact of androgen deprivation on the sildenafil response in patients with erectile dysfunction following radiation therapy. MATERIALS AND METHODS: Patients were enrolled prospectively if they underwent radiation therapy in the form of 3-dimensional conformal external beam or brachytherapy with or without androgen deprivation, reported functional erections before radiation therapy, experienced the onset of erectile dysfunction following the completion of radiation therapy, had comprehensive erectile dysfunction evaluation, including a thorough history and physical examination, attempted sildenafil periodically and completed the International Index of Erectile Function on at least 2 occasions throughout the first 3 years following the completion of radiation therapy. RESULTS: A total of 152 patients were enrolled. Mean age +/- SD was 62 +/- 14 years. No significant difference existed in age or radiation dose between patients with and without androgen deprivation exposure. Mean androgen deprivation duration was 3.8 +/- 1.8 months. For patients with conformal external beam and brachytherapy the sildenafil response, mean erectile function domain score and percent who experienced erectile function domain normalization at each time point were lower in those with vs without androgen deprivation. CONCLUSIONS: Androgen deprivation seems to exert a deleterious effect on erectile function in men undergoing radiation therapy for prostate cancer. This was observed in men treated with conformal external beam and brachytherapy at short-term, medium term and long-term followup.


Assuntos
Antagonistas de Androgênios/administração & dosagem , Braquiterapia/efeitos adversos , Disfunção Erétil/tratamento farmacológico , Piperazinas/administração & dosagem , Neoplasias da Próstata/radioterapia , Radioterapia Conformacional/efeitos adversos , Sulfonas/administração & dosagem , Idoso , Braquiterapia/métodos , Disfunção Erétil/etiologia , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Pênis/irrigação sanguínea , Pênis/efeitos dos fármacos , Inibidores de Fosfodiesterase/administração & dosagem , Estudos Prospectivos , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/mortalidade , Purinas/administração & dosagem , Radioterapia Conformacional/métodos , Medição de Risco , Citrato de Sildenafila , Estatísticas não Paramétricas , Resultado do Tratamento
9.
Int J Radiat Oncol Biol Phys ; 62(1): 3-19, 2005 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-15850897

RESUMO

PURPOSE: To perform a systematic review of the evidence to determine the efficacy and effectiveness of three-dimensional conformal radiotherapy (3D-CRT) for localized prostate cancer; provide a clear presentation of the key clinical outcome questions related to the use of 3D-CRT in the treatment of localized prostate cancer that may be answered by a formal literature review; and provide concise information on whether 3D-CRT improves the clinical outcomes in the treatment of localized prostate cancer compared with conventional RT. METHODS AND MATERIALS: We performed a systematic review of the literature through a structured process developed by the American Society for Therapeutic Radiology and Oncology's Outcomes Committee that involved the creation of a multidisciplinary task force, development of clinical outcome questions, a formal literature review and data abstraction, data review, and outside peer review. RESULTS: Seven key clinical questions were identified. The results and task force conclusions of the literature review for each question are reported. CONCLUSION: The technological goals of reducing morbidity with 3D-CRT have been achieved. Randomized trials and follow-up of completed trials remain necessary to address these clinical outcomes specifically with regard to patient subsets and the use of hormonal therapy.


Assuntos
Neoplasias da Próstata/radioterapia , Radioterapia Conformacional/métodos , Intervalo Livre de Doença , Medicina Baseada em Evidências , Humanos , Masculino , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/patologia , Lesões por Radiação/prevenção & controle , Radioterapia (Especialidade) , Resultado do Tratamento
11.
Int J Radiat Oncol Biol Phys ; 55(4): 970-8, 2003 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-12605975

RESUMO

PURPOSE: In three-dimensional conformal radiotherapy (3D-CRT), penile tissues adjacent to the prostate are exposed to significant doses of radiation. This is likely to be a factor in development of posttreatment erectile dysfunction. In this study, we investigate whether intensity-modulated radiation therapy (IMRT) leads to lower radiation exposure to proximal penile tissues (PPT) when compared with 3D-CRT. MATERIALS AND METHODS: Ten randomly selected patients with clinically localized prostate cancer constituted the study group. Using identical structure sets, 3D-CRT and IMRT plans were designed for each patient. For IMRT, both tomographic (TOMO) and step-and-shoot (SS) techniques were used. Treatment plans were developed using 18 MV photons for 3D-CRT, 6 MV photons for TOMO, and 6 MV and 18 MV photons for SS plans. The PPT up to the beginning of the penile shaft (usually measuring 2-3 cm) was outlined by a team composed of a board-certified urologist and a radiation oncologist. The outlined PPT was subdivided into three segments (P1, P2, P3), and the radiation dose to each segment and to the entire structure was calculated. In addition, PPT was subdivided into corporal cavernosa (CC) and corpus spongiosum (bulb). The prostate dose was escalated from 73.8 Gy to 81 Gy to 90 Gy. Target D(95) (dose to 95% volume), critical structure D(5) (dose to 5% volume), and D(mean) (mean dose) were used in the comparison among treatment plans. Because 3D-CRT uses larger field margins than does IMRT, target and critical structure doses were recalculated in 3D-CRT plans employing field margins obtained from IMRT plans. Planning target volumes in original and modified 3D-CRT plans were the same. RESULTS: Compared with 3D-CRT plans, the mean PPT doses were reduced by 40.2%, 43.6%, and 46.2%, respectively, at the three prescription dose levels in TOMO plans. The average D(mean) for CC was lower by 46.4%, 48.4%, and 51.4%, whereas the average bulb D(mean) was reduced by 44.2%, 44.9%, and 47.9%, respectively. There was also considerable sparing of P1, with a reduction in average D(mean) of 41.9%, 45.5%, and 48.5% compared with 3D-CRT. All differences between 3D-CRT and IMRT doses were statistically significant (p < 0.001). Similar improvements were noticed in maximum doses (D(5)) for penile structures. The percent dose reduction with IMRT plans improved as prostate dose was escalated. When compared with 3D-CRT plans with reduced fields, IMRT plans showed slightly smaller but still significant improvements in critical structure doses (p < 0.001). Compared with SS plans, TOMO plans produced improved sparing of dose to critical structures. CONCLUSIONS: IMRT allows for dose escalation in prostate cancer while keeping penile tissue doses significantly lower compared to conformal radiotherapy. This may result in improved potency rates over current results observed with 3D-CRT.


Assuntos
Doenças do Pênis/prevenção & controle , Neoplasias da Próstata/radioterapia , Lesões por Radiação/prevenção & controle , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Humanos , Masculino , Dosagem Radioterapêutica , Tomografia Computadorizada por Raios X/métodos
12.
Int J Radiat Oncol Biol Phys ; 56(2): 427-35, 2003 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-12738317

RESUMO

BACKGROUND: Literature regarding incidence of site-specific second cancers after laryngeal cancer is limited. Risk factors associated with second primaries are unknown. METHODS: Second primaries after laryngeal cancer in the SEER database (1973-1996) were analyzed for incidence, relative risk compared with the general population, and potential risk factors, including radiotherapy. Information on chemotherapy and tobacco smoking was not available in the SEER database. RESULTS: Of 20,074 laryngeal cancer patients surviving at least 3 months, 3533 (17.6%) developed second cancers. The cumulative risk of developing a second cancer was 26% at 10 years and 47% at 20 years. Compared with age-adjusted, gender, and tumor-specific rates in the general population, laryngeal cancer patients had higher risks of second cancers overall (observed-to-expected ratio [O/E] = 1.68, 95% confidence interval [CI] = 1.58-1.79), head-and-neck (4.81 [4.31-5.58]), esophageal (3.99 [3.29-4.83]), and lung (3.56 [3.34-3.79]) cancer. Advanced age at initial diagnosis was associated with increased risks of second cancers (p = 0.0001). Radiotherapy was associated with increased risk of second cancers overall (relative risk [RR] = 1.10 [1.02-1.18], p = 0.012), especially second cancers of the lung (RR = 1.18, [1.05-1.33], p = 0.006) and possibly second cancers of the head and neck (RR = 1.26, [0.99-1.60], p = 0.061). Radiotherapy was associated with a 68% excess risk (RR = 1.68, [1.16-2.43], p = 0.007) of developing a second head-and-neck cancer in patients who survived more than 5 years. Second primary was associated with a poor survival (p = 0.0001). CONCLUSIONS: Second cancers after laryngeal cancer are common, especially for long-term survivors. Radiotherapy was associated with a small increased risk of developing second cancers overall and long-term risk of head-and-neck cancers. This data should be interpreted with caution in light of the lack of information on chemotherapy and tobacco smoking in the SEER database. Prevention and early detection are indicated.


Assuntos
Carcinoma de Células Escamosas/epidemiologia , Neoplasias Laríngeas/epidemiologia , Segunda Neoplasia Primária/epidemiologia , Análise de Variância , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/radioterapia , Intervalos de Confiança , Feminino , Humanos , Neoplasias Laríngeas/mortalidade , Neoplasias Laríngeas/radioterapia , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Risco , Taxa de Sobrevida , Sobreviventes
13.
Int J Radiat Oncol Biol Phys ; 53(2): 483-9, 2002 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-12023153

RESUMO

PURPOSE: To investigate the magnitude of edema after prostate brachytherapy and its effect on the CT-based postimplant dosimetry based on the sequential CT scans using dose-volume histograms, dose conformity, and homogeneity indices in patients with prostate cancer. METHODS AND MATERIALS: CT scans were obtained for 25 patients who underwent prostate brachytherapy with 125I or 103Pd before implant and postimplant Day 1, Day 7, and Day 28. The prostate, rectum, and bladder volumes on each scan were contoured by the same physician. Posttreatment dose distributions were generated using FOCUS (CMS Inc., St. Louis, MO) brachytherapy planning software. Dose calculations were based on TG43 formalism. Dose-volume histograms for target, rectum, and bladder were created for all patients, and the quality of the implants was analyzed using the dose conformity indices: CT-based target volumes ratios, TVR(1) and TVR(2); dose homogeneity indices, DHI(1), DHI(2), and DNR; dose coverage index, CI; the percentage of the prostate volume enclosed by 100%, 90%, and 80% of the prescription dose: V(100), V(90), and V(80); the volume of the rectum covered by 100%, 80%, and 70% of the prescription dose; and the dose covering 90% of the prostate volume (D(90)). RESULTS: The prostate volume increased between the prescan and the implant Day 1 scans and then decreased between Day 1 and Day 28 scans. The average increase in prostate volume was 30% between the prescan and implant Day 1 scans for the 25 cases evaluated. The prostate volume decreased 20% between the Day 1 and Day 28 scans. The preplan dose coverage to the periphery of the prostate was 100% for all cases evaluated. V(100) increased from an average of 77% to 85% between the Day 1 and Day 28 scans, respectively. On average, D(90) increased from 84% for Day 1 to 93% for Day 28. The average TVR(1), TVR(2), and CI were 1.99, 2.28, and 0.87, respectively, based on the Day 28 scans. The average DHI(1), DHI(2), and DNR were 0.52, 0.46, and 0.48, respectively, based on the Day 28 scans. CONCLUSIONS: The decrease in prostate volume from Day 1 to Day 28 after the implant markedly improved the prescription dose covering the prostate from 77% to 85%. Day 28 prostate volumes were still about 10% larger than the preimplant CT volumes for the 25 cases evaluated. Postimplant dosimetry using dose conformity and homogeneity indices is dependent on the timing of CT studies, as a result of changing prostate volumes from edema.


Assuntos
Braquiterapia/efeitos adversos , Edema/diagnóstico por imagem , Doenças Prostáticas/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Edema/etiologia , Edema/patologia , Humanos , Radioisótopos do Iodo/uso terapêutico , Masculino , Paládio/uso terapêutico , Fenômenos Físicos , Física , Doenças Prostáticas/etiologia , Doenças Prostáticas/patologia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Radioisótopos/uso terapêutico , Dosagem Radioterapêutica , Reto/diagnóstico por imagem , Reto/patologia , Tomografia Computadorizada por Raios X , Bexiga Urinária/diagnóstico por imagem , Bexiga Urinária/patologia
14.
Int J Radiat Oncol Biol Phys ; 57(5): 1480-91, 2003 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-14630288

RESUMO

PURPOSE: Because of biologic, medical, and sometimes logistic reasons, patients may be treated with 3D conformal therapy or intensity-modulated radiation therapy (IMRT) for the initial treatment volume (PTV(1)) followed by a sequential IMRT boost dose delivered to the boost volume (PTV(2)). In some patients, both PTV(1) and PTV(2) may be simultaneously treated by IMRT (simultaneous integrated boost technique). The purpose of this work was to assess the sequential and simultaneous integrated boost IMRT delivery techniques on target coverage and normal-tissue sparing. MATERIALS AND METHODS: Fifteen patients with head-and-neck (H&N), lung, and prostate cancer were selected for this comparative study. Each site included 5 patients. In all patients, the target consisted of PTV(1) and PTV(2). The prescription doses to PTV(1) and PTV(2) were 46 Gy and 66 Gy (H&N cases), 45 Gy and 66.6 Gy (lung cases), 50 Gy and 78 Gy (prostate cases), respectively. The critical structures included the following: spinal cord, parotid glands, and brainstem (H&N structures); spinal cord, esophagus, lungs, and heart (lung structures); and bladder, rectum, femurs (prostate structures). For all cases, three IMRT plans were created: (1) 3D conformal therapy to PTV(1) followed by sequential IMRT boost to PTV(2) (sequential-IMRT(1)), (2) IMRT to PTV(1) followed by sequential IMRT boost to PTV(2) (sequential-IMRT(2)), and (3) Simultaneous integrated IMRT boost to both PTV(1) and PTV(2) (SIB-IMRT). The treatment plans were compared in terms of their dose-volume histograms, target volume covered by 100% of the prescription dose (D(100%)), and maximum and mean structure doses (D(max) and D(mean)). RESULTS: H&N cases: SIB-IMRT produced better sparing of both parotids than sequential-IMRT(1), although sequential-IMRT(2) also provided adequate parotid sparing. On average, the mean cord dose for sequential-IMRT(1) was 29 Gy. The mean cord dose was reduced to approximately 20 Gy with both sequential-IMRT(2) and SIB-IMRT. Prostate cases: The volume of rectum receiving 70 Gy or more (V(>70 Gy)) was reduced to 18.6 Gy with SIB-IMRT from 22.2 Gy with sequential-IMRT(2). SIB-IMRT reduced the mean doses to both bladder and rectum by approximately 10% and approximately 7%, respectively, as compared to sequential-IMRT(2). The mean left and right femur doses with SIB-IMRT were approximately 32% lower than obtained with sequential-IMRT(1). Lung cases: The mean heart dose was reduced by approximately 33% with SIB-IMRT as compared to sequential-IMRT(1). The mean esophagus dose was also reduced by approximately 10% using SIB-IMRT as compared to sequential-IMRT(1). The percentage of the lung volume receiving 20 Gy (V(20 Gy)) was reduced to 26% by SIB-IMRT from 30.6% with sequential-IMRT(1). CONCLUSIONS: For equal PTV coverage, both sequential-IMRT techniques demonstrated moderately improved sparing of the critical structures. SIB-IMRT, however, markedly reduced doses to the critical structures for most of the cases considered in this study. The conformality of the SIB-IMRT plans was also much superior to that obtained with both sequential-IMRT techniques. The improved conformality gained with SIB-IMRT may suggest that the dose to nontarget tissues will be lower.


Assuntos
Neoplasias de Cabeça e Pescoço/radioterapia , Neoplasias Pulmonares/radioterapia , Neoplasias da Próstata/radioterapia , Radioterapia Conformacional/métodos , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Humanos , Imageamento Tridimensional , Neoplasias Pulmonares/diagnóstico por imagem , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Eficiência Biológica Relativa , Tomografia Computadorizada por Raios X
15.
Arch Surg ; 139(5): 532-8; discussion 538-9, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15136354

RESUMO

HYPOTHESIS: Patients receiving neoadjuvant chemoradiotherapy followed by surgery (CRS) undergo downstaging of their tumor and have improved survival when compared with patients undergoing surgery followed by adjuvant chemoradiotherapy (SCR). DESIGN: Retrospective study. SETTING: Tertiary-care university medical center. PATIENTS: One hundred twenty-three patients with squamous cell carcinoma and adenocarcinoma of the esophagus underwent Ivor-Lewis esophagectomy from January 1, 1990, through December 31, 2001. Of these, 31 received CRS; 27, SCR; and 65, surgery alone. INTERVENTIONS: Patients were candidates for neoadjuvant or adjuvant therapy if they had locally advanced disease (T3/T4 N0 or any T stage with N1). Neoadjuvant and adjuvant therapies were nonrandomized and based on the preference of the treating oncologist and surgeon. MAIN OUTCOME MEASUREMENTS: Pathological downstaging was analyzed in the patients receiving CRS. Operative mortality, postoperative morbidity, median survival, and overall survival were compared between the CRS and SCR groups. RESULTS: Pathological downstaging (as characterized by TNM staging) was observed in 20 (64%) of the patients receiving CRS. Complete pathological responses occurred in 5 (16%) of the patients undergoing CRS. No 30-day mortality was observed in either treatment group. No statistical difference in survival was observed between groups, although a trend suggested improved survival with neoadjuvant therapy (3-year survival in CRS and SCR groups was 45% and 22%, respectively; P =.15). Complete pathological responders in the CRS group had a 1-year survival of 80% compared with 29% in nonresponders (P =.25). No statistical differences were observed between groups in relation to blood loss, length of hospital stay, mortality, or morbidity. CONCLUSIONS: Neoadjuvant chemoradiotherapy effectively downstages cancer in patients with locally advanced esophageal disease. Morbidity and operative mortality were not significantly different between patients receiving neoadjuvant and adjuvant therapy. The difference in overall survival between the 2 groups did not reach statistical significance, although a trend at 3 years was observed.


Assuntos
Adenocarcinoma/mortalidade , Adenocarcinoma/cirurgia , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/cirurgia , Terapia Neoadjuvante , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/radioterapia , Idoso , Carcinoma de Células Pequenas/mortalidade , Carcinoma de Células Pequenas/cirurgia , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/radioterapia , Carcinoma de Células Escamosas/cirurgia , Quimioterapia Adjuvante , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/radioterapia , Esofagectomia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Radioterapia Adjuvante , Estudos Retrospectivos , Análise de Sobrevida
16.
Brachytherapy ; 1(4): 195-203, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-15062167

RESUMO

PURPOSE: (125)I permanent seed brachytherapy for prostate cancer produces good clinical outcomes and limits radiation exposure to medical staff and patients' families. However, (125)I seeds cost thousands of dollars per implant. An encapsulated (192)Ir permanent seed possibly could cost less than 10 dollars. Could inexpensive permanent (192)Ir seeds be used for prostate implants? METHODS AND MATERIALS: We review the radiobiology of permanent implants, calculate the (192)Ir permanent seed air kerma strength (activity) required, simulate (125)I and (192)Ir seed implants and mixtures thereof, calculate exposure rates near simulated (192)Ir prostate patients, calculate potential radiation exposure to medical staff and family members, review patient release regulations, and analyze the potential cost benefits of using (192)Ir permanent seed implants. RESULTS: Low air kerma strength (<0.4 microGy m(2)/h/seed) [activity < 0.1-mCi/seed; <0.0558 mg Ra eq/seed] permanent (192)Ir seed implants yield more uniform prostate doses than (125)I seed implants and acceptable urethra, bladder, and rectal doses. The (192)Ir 73.83-day half-life allows mixing (192)Ir seeds and (125)I seeds. CONCLUSIONS: We believe medical staff could safely implant 40 microGy m(2)/h [10-mCi; 5.58 mg Ra eq] (192)Ir per case. Occupancy factors (1/8, 1/16) could acceptably limit families' exposures. Seed costs could be reduced markedly. With adequate protection of medical staff and proper instructions to patients post-implant, low air kerma strength (<0.4 microGy m(2)/h/seed) [activity <0.1-mCi/seed; <0.0558 mg Ra eq/seed] (192)Ir permanent seed implants are feasible in large patients, with mixed ((125)I, (92)Ir) seed implants feasible for modest size patients. Such implants could be useful in populous countries (China, India, Brazil) and for others who find (125)I seed implants too expensive to perform.


Assuntos
Braquiterapia/métodos , Radioisótopos de Irídio/uso terapêutico , Neoplasias da Próstata/radioterapia , Braquiterapia/efeitos adversos , Braquiterapia/economia , Custos e Análise de Custo , Saúde da Família , Estudos de Viabilidade , Humanos , Masculino , Exposição Ocupacional , Radiobiologia , Radiologia , Dosagem Radioterapêutica
18.
Pract Radiat Oncol ; 2(3): 210-225, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-25925626

RESUMO

PURPOSE: To systematically review the evidence for the radiotherapeutic and surgical management of patients newly diagnosed with intraparenchymal brain metastases. METHODS AND MATERIALS: Key clinical questions to be addressed in this evidence-based Guideline were identified. Fully published randomized controlled trials dealing with the management of newly diagnosed intraparenchymal brain metastases were searched systematically and reviewed. The U.S. Preventative Services Task Force levels of evidence were used to classify various options of management. RESULTS: The choice of management in patients with newly diagnosed single or multiple brain metastases depends on estimated prognosis and the aims of treatment (survival, local treated lesion control, distant brain control, neurocognitive preservation). Single brain metastasis and good prognosis (expected survival 3 months or more): For a single brain metastasis larger than 3 to 4 cm and amenable to safe complete resection, whole brain radiotherapy (WBRT) and surgery (level 1) should be considered. Another alternative is surgery and radiosurgery/radiation boost to the resection cavity (level 3). For single metastasis less than 3 to 4 cm, radiosurgery alone or WBRT and radiosurgery or WBRT and surgery (all based on level 1 evidence) should be considered. Another alternative is surgery and radiosurgery or radiation boost to the resection cavity (level 3). For single brain metastasis (less than 3 to 4 cm) that is not resectable or incompletely resected, WBRT and radiosurgery, or radiosurgery alone should be considered (level 1). For nonresectable single brain metastasis (larger than 3 to 4 cm), WBRT should be considered (level 3). Multiple brain metastases and good prognosis (expected survival 3 months or more): For selected patients with multiple brain metastases (all less than 3 to 4 cm), radiosurgery alone, WBRT and radiosurgery, or WBRT alone should be considered, based on level 1 evidence. Safe resection of a brain metastasis or metastases causing significant mass effect and postoperative WBRT may also be considered (level 3). Patients with poor prognosis (expected survival less than 3 months): Patients with either single or multiple brain metastases with poor prognosis should be considered for palliative care with or without WBRT (level 3). It should be recognized, however, that there are limitations in the ability of physicians to accurately predict patient survival. Prognostic systems such as recursive partitioning analysis, and diagnosis-specific graded prognostic assessment may be helpful. CONCLUSIONS: Radiotherapeutic intervention (WBRT or radiosurgery) is associated with improved brain control. In selected patients with single brain metastasis, radiosurgery or surgery has been found to improve survival and locally treated metastasis control (compared with WBRT alone).

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA