RESUMO
In 1998, an editorial from the International Journal of Radiation Oncology - Biology - Physics (IJROBP) on the occasion of the publication of Phase I by Zelefsky et al. on 3D radiotherapy dose escalation asked the question: "will more prove better?". More than 20 years later, several prospective studies have supported the authors' conclusions, making dose escalation a new standard in prostate cancer. The data from prospective randomized studies were ultimately disappointing in that they failed to show an overall survival benefit from dose escalation. However, there is a clear and consistent benefit in biochemical recurrence-free survival, which must be weighed on an individual patient basis against the potential additional toxicity of dose escalation. Techniques and concepts have become more and more precise, such as intensity modulated irradiation, simultaneous integrated boost, hypofractionated dose-escalation, pelvic irradiation with involved node boost or focal dose-escalation on gross recurrence after prostatectomy. The objective here was to summarize the prospective data on dose escalation in prostate cancer and in particular on recent advances in the field. In 2022, can we finally say that more has proven better?
Assuntos
Braquiterapia , Neoplasias da Próstata , Radioterapia de Intensidade Modulada , Braquiterapia/métodos , Humanos , Masculino , Estudos Prospectivos , Prostatectomia , Neoplasias da Próstata/tratamento farmacológico , Radioterapia de Intensidade Modulada/métodos , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Because of the physical properties of proton beam radiation therapy (PT), which allows energy to be deposited at a specific depth with a rapid energy fall-off beyond that depth, PT has several theoretical advantages over photon radiation therapy for esophageal cancer (EC). Protons have the potential to reduce the dose to healthy tissue and to more safely allow treatment of tumors near critical organs, dose escalation, trimodal treatment, and re-irradiation. In recent years, larger multicenter retrospective studies have been published showing excellent survival rates, lower than expected toxicities and even better outcomes with PT than with photon radiotherapy even using IMRT or VMAT techniques. Although PT was associated with reduced toxicities, postoperative complications, and hospital stays compared to photon radiation therapy, these studies all had inherent biases in relation with patient selection for PT. These observations were recently confirmed by a randomized phase II study in locally advanced EC that showed significantly reduced toxicities with protons compared with IMRT. Currently, two randomized phase III trials (NRG-GI006 in the US and PROTECT in Europe) are being conducted to confirm whether protons could become the standard of care in locally advanced and resectable esophageal cancers.
Assuntos
Neoplasias Esofágicas , Terapia com Prótons , Radioterapia de Intensidade Modulada , Reirradiação , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/radioterapia , Humanos , Terapia com Prótons/efeitos adversos , Prótons , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Estudos RetrospectivosAssuntos
Adenocarcinoma/secundário , Ácidos Carboxílicos , Ciclobutanos , Radioisótopos de Flúor , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Neoplasias da Próstata/patologia , Compostos Radiofarmacêuticos , Radiocirurgia , Radioterapia Guiada por Imagem , Neoplasias da Coluna Vertebral/secundário , Vértebras Torácicas/diagnóstico por imagem , Adenocarcinoma/sangue , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/radioterapia , Idoso , Diagnóstico Diferencial , Humanos , Calicreínas/sangue , Imageamento por Ressonância Magnética , Masculino , Antígeno Prostático Específico/sangue , Prostatectomia , Neoplasias da Próstata/sangue , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/cirurgia , Terapia de Salvação , Neoplasias da Coluna Vertebral/sangue , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Neoplasias da Coluna Vertebral/radioterapiaRESUMO
Whole-breast normofractionated irradiation following breast-conserving surgery is the reference treatment. It delivers a dose of 50Gy in 25 fractions of 2Gy to the reference point, and, in some patients, an additional dose of 16Gy in 8 fractions of 2Gy in the tumor bed. Long-term results and toxicity of this irradiation scheme was prospectively evaluated in several randomised trials and meta-analyses, in invasive cancers as well as in ductal carcinoma in situ. The average 10-year rate of in breast recurrences was 6 % in these trials, with limited cardiac and pulmonary toxicity and limited rate of severe fibrosis. Identification of risk factors of recurrences may help to design new irradiation schemes adapted to tumor biology. The new irradiation schemes must be rigorously evaluated in the long-term in the frame of prospective clinical trials, in order to validate them as new standards of treatment.