Relapse and gastrointestinal toxicity associated with radiotherapy treatment in stage I seminoma patients

Abstract

Background

The results preceding this study documented that patients with early stage classical seminoma treated with radiotherapy in the Hospital General de Mexico, using doses of 30 Gy in 15 fractions using the modified dog-leg technique have lower gastrointestinal toxicity than the conventional dog-leg technique, but with no difference in overall survival and disease-free survival, both resulting in 100% 60 month-survival.

Objective

To determine the results of treatment in terms of relapse and gastrointestinal toxicity, comparing radiotherapy with conventional dog-leg, modified dog-leg and inverted-Y techniques.

Material and methods

retrospective, observational, comparative, analytical, retrolective study; 40 patients were analysed, all diagnosed with stage I seminoma treated at the RT Hospital General de Mexico between October 2009 and May 2016.

Results

The age of the patients was 33 ± 8 years; 32 (80%) were treated in Accelerator linear and 8 patients (20%) in cobalt-60. The modified dog-leg technique was used in 24 patients (60%), conventional dog-leg technique in 12 patients (30%), and inverted-Y technique in 4 patients (10%). The radiation dose in 87% of patients was 25.2 Gy. The most commonly found acute gastrointestinal toxicity was grade 2, present in 22% with modified dog-leg technique, 13% conventional dog-leg technique, and 3% for the inverted-Y technique (p = 0.95). There was one relapse associated with the modified dog-leg technique; predicting factors for relapse including rete testis invasion, trans-scrotal violation, and lymphovascular invasion had no statistically significant impact.

Conclusions

Radiotherapy continues to be the treatment of choice in patients with early stage seminoma, with a low probability of relapse and acceptable gastrointestinal toxicity. There is no difference in relapse or gastrointestinal toxicity associated with the different radiation techniques in patients with stage I seminoma, therefore the modified dog-leg technique is recommended as the field of irradiation is already reduced without a negative impact on relapse.