Long term results of definitive radiotherapy for cervical carcinoma using four applications of high dose rate afterloading.

Abstract

In definitive radiotherapy for cervical carcinoma, combined modality treatment using external beam radiotherapy and brachytherapy is standard. Although the optimal number of afterloading applications is controversial, the majority of authors recommend three applications. In this study, the authors investigated the use of 4 applications with iridium-192 afterloading with a dose of 7.5 grays (Gy). Standardized radiotherapy doses were adapted to the individual tumor anatomy using a prospective schedule. In the 73 study patients, actuarial and tumor-related 5-year survival rates by T classification were: T1b: 30% (100% cause specific survival); T2a: 55% (76% cause specific survival); T2b: 50% (60% cause specific survival); T3a: 50% (67% cause specific survival); T3b: 39% (50% cause specific survival); and T4a: 40% (40% cause specific survival). Morbidity, graded according to the National Cancer Institute's Common Toxicity Criteria (CTC) were low: CTC Grade 1: 7 patients (7.6%); CTC Grade 2: 7 patients (7.6%); CTC Grade 3: 1 patient (1.4%); and CTC Grade 4: 1 patient (1.4%). In a multivariate analysis, the T classification was the only significant independent prognostic factor for actuarial survival, tumor related (cause specific) survival, local tumor control and freedom of metastatic disease. The number of afterloading applications was an independent prognostic factor for local tumor control. Based on the long term results of the current study, external beam radiotherapy combined with 4 afterloading high dose rate applications (total of 30 Gy) appears to be clinically feasible and results in satisfactory survival rates and few side effects.