RESUMO
PURPOSE OF INVESTIGATION: To add to the existing outcome data regarding radical radiotherapy (RT) for FIGO Stage I and II cervical cancer in a mono-institutional series and to evaluate the cost-benefit ratio of the addition of brachytherapy (BRA) to external-beam radiotherapy (EBRT). MATERIALS AND METHODS: The authors report on 240 patients (pts) with FIGO Stage I and II cervical cancer, consecutively treated with radical RT from 1990 through 2009 at the Istituto del Radio "O. Alberti" (EBRT alone, 32, EBRT and BRA, 189, BRA alone, 19). BRA was delivered with low dose rate (LDR, 133.64%) until 2003 and then with high dose rate (HDR, 75.36%). RT was associated with concomitant chemotherapy (CHT), mainly weekly cisplatin 40 mg/m2, in 87 pts, mostly after 2000. The Chi-square test was used to compare the different variables, the Log-Rank test to compare the actuarial survival values, and the Cox-model for the multivariate analysis. RESULTS: Five-year actuarial overall survival (OS) equalled 65%, disease specific survival (DSS) 77%. Regardless of disease stage, better DSS was evident in pts treated with EBRT and BRA compared with those treated with EBRT alone (82% and 58% respectively, p = 0.005); pts treated with concomitant CHT (dose intensity > or = 50%) and higher RT doses (RT cumulative EQD2 > or = 75 Gy) obtained better DSS. Complete response (CR) rate approached 88.4% (206/233 evaluable pts) and more than half of the subsequent failures (21/36) were in distant sites. Older patients and those given BRA had better OS and DSS, while BRA dose rate did not result related with these outcomes. Chronic G3/G4 toxicity involved more frequently the intestinal/rectal tract than other organs at risk. Rectal and vaginal serious chronic sequelae developed mainly in pts treated with EBRT and BRA and suggest the need for more advanced treatment techniques. CONCLUSIONS: the present mono-institutional analysis confirms the efficacy of radical RT for the treatment of cervical cancer and provides support to the role of BRA to obtain better outcomes. An effort to reduce long-term toxicity of the treatment is needed.
Assuntos
Adenocarcinoma/radioterapia , Carcinoma Adenoescamoso/radioterapia , Carcinoma de Células Escamosas/radioterapia , Neoplasias do Colo do Útero/radioterapia , Braquiterapia/métodos , Quimioterapia Adjuvante , Terapia Combinada , Intervalo Livre de Doença , Feminino , Humanos , Pessoa de Meia-Idade , Análise Multivariada , Modelos de Riscos Proporcionais , Radioterapia/métodos , Estudos Retrospectivos , Resultado do Tratamento , Neoplasias do Colo do Útero/tratamento farmacológicoRESUMO
Lipowitz's metal is widely employed in radiotherapy to create shielding blocks and compensators for X- and gamma-rays. Its effect in modifying radiation beams cannot be evaluated in a simple manner: therefore, in our opinion, an experimental approach to the problem is the most suitable one. Attenuation for Lipowitz's metal and lead was measured in some different geometrical setups, for a 5 MV linac and a 60Co unit. Transmitted fraction vs attenuator thickness curves were obtained. The influence of attenuators on depth-dose curves in a phantom was also evaluated: the results confirm the need to use data obtained in conditions as close as possible to the operative ones, in treatment planning as well as in studying and realizing calculation models.