Oncological Outcomes and Toxicities of Brachytherapy for Carcinomas of the Penis: A Bi-Centric Study by the SFRO Brachytherapy Group

• Published in: International journal of radiation oncology, biology, physics Vol. 120; no. 2; p. S75
• Main Authors: KA, K., Schiappa, R., Espenel, S., Hannoun-Levi, J.M., Chargari, C.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.10.2024
• ISSN: 0360-3016
• DOI: 10.1016/j.ijrobp.2024.07.130

Total glansectomy and brachytherapy represent therapeutic choices for penile cancers. However, to avoid the functional sequelae associated with surgery, organic preservation via brachytherapy presents itself as an alternative. In this study, we present the results of the GC-SFRO cohort, highlighting the oncological efficacy and toxicity profiles in patients who opted for brachytherapy in the treatment of penile cancers. Patients with histological evidence of localized prostate cancers were included. All patients underwent brachytherapy treatment using different techniques at different centers. Oncological results at 5 years and toxicity were assessed. Different survival criteria were considered, such as local relapse-free survival (LRFS), metastatic relapse-free survival (MDFS), penectomy-free survival, which includes local relapse and/or severe complication requiring penile removal, and overall survival (OS), which includes death from any other cause. Survival data were presented graphically using Kaplan-Meier curves. The Log-Rank test was used to compare these curves. In order to identify prognostic factors influencing oncological outcome, univariate and multivariate Cox models were planned. All statistical analyses were performed using R software version 3.6.1. Over the period 1970-2020, there were 296 patients who underwent brachytherapy, divided into 56.3% LDR, 9.9% HDR and 33.8% PDR. The average age of patients was 62 years (standard deviation = 12.7). The majority of patients (81.9%) had a mean lesion diameter of 30 mm or less, and 80.9% were classified as N0. Twenty patients (9.76%) required external lymph node radiotherapy, with a mean dose of 45.1 Gy (SD = 10.4). After a mean follow-up of 87.7 months (SD = 76.8), 70 relapses (30.3%) were observed, of which 17.8% were local, 15.2% lymph node and 9.52% metastatic. At 5 years, progression-free survival (PFS), local relapse-free survival (LRFS), overall survival (OS) and penectomy-free survival were 77% (71-83), 82% (77-88), 78% (72-84) and 80% (75-87) respectively. In bivariate analysis, tumor size greater than 3 cm was a factor influencing PFS (P = 0.02) and penectomy-free survival (P = 0.001), while a history of precancerous lesion was associated with OS (P = 0.03). In bivariate and multivariate analysis, the presence of inguinal nodes was significantly associated with PFS and metastatic relapse-free survival (MRFS), with HRs of 4.37 (CI = 1.61-11.86) and 6.07 (CI = 1.01-36.60) respectively. Acute toxicity grade ≥ 2 was 37.7%, urethral stricture 23.8% and painful ulceration 19.9%. Only 15 patients, or 7.4%, required surgery for complications. The GC-SFRO cohort of brachytherapy patients with cancer of the penis is the largest to date. Brachytherapy is an important option for organ preservation in penile cancer, with good oncological and functional results.