ESTRO 2024 - Abstract Book

S2497

Clinical - Urology

ESTRO 2024

2087

Digital Poster

ADJUVANT THERAPY FOR CLASSICAL SEMINOMA: A RETROSPECTIVE COHORT OF RADIOTHERAPY VERSUS CHEMOTHERAPY

Dayane Innocente Souza

Barretos Cancer Hospital, Radiotherapy, Barretos, Brazil

Purpose/Objective:

Pure seminoma has high survival rates, and the adjuvant treatment modality as well as its long term-related events can affect the clinical outcomes. Although chemotherapy (CHT) is the current standard treatment after surgery, radiotherapy (RT) successfully been used in the adjuvant phase for decades. Both modalities are efficient, but there are concerns about the acute and late toxicity related to ionizing radiation. in addition to the potential risk of a second radiation-induced neoplasia. Here we present a 10 years retrospective analysis comparing adjuvant CHT and RT, for classical seminoma in a single institution.

Material/Methods:

In this retrospective cohort, data from the medical records of 86 patients with classic seminoma, EC I-IIB, who underwent adjuvant treatment between 2000 and 2019 were analyzed. All patients underwent surgery and adjuvant treatment at a single institution.

Results:

The median age was 36 years, with a higher proportion of T1-2 (93%) and N0-1 staging (93%). With a median follow up of 131 months, overall survival (OS) at 5 years was 98.8%. 56 patients had indication for RT, predominantly treated with the 2D technique (39 patients, 75%) and with a median dose of 25,50 Gy in 17 fractions until 2014. CHT was established as the standard in the subsequent years. Carboplatin was the main choice for CHT (15 patients, 32.8%). The univariate analysis showed no difference in OS between RT and adjuvant CHT (p= 0.757). Progression free survival for RT was 100% and 96.9% for CHT (p=0.195), with 1.9% regional failure. There was no distant failure for RT or CHT. The univariate analysis did not identify any variables as worse prognostic factors. Specific cancer survival was 100% for both RT and CHT. The CHT group had grade 3 or higher toxicity of 3.4%, insufficient erection at 28.6%, and impaired fertility at 50% compared to RT at 33.4%. No additional toxicities were found for RT group. There were no cases of second primary tumor in the irradiated field.

Conclusion:

The analysis of institutional experience showed that radiotherapy remains a safe and effective treatment option for classic seminoma, offering effective clinical results, with no increase in treatment-related events when compared to chemotherapy