High-dose rate brachytherapy in localized penile cancer: 5-Year clinical outcome analysis

PURPOSE: To analyze the oncological outcome and toxicity profile after conservative treatment based on multicatheter interstitial high-dose rate brachytherapy (MHB) for patients presenting a localized penile cancer. MATERIALS AND METHODS: Patients with histologically proven, non-metastatic (T1-T2 N0-N2 M0) localized penile cancer were treated with MHB. Needles were placed under general anesthesia into the target volume using a dedicated template. Treatment planning was performed using a post-implant CT-scan to deliver 35 Gy or 39 Gy (9f, 5d) for adjuvant or definitive treatment respectively. Five-year oncological outcome was evaluated with local relapse-free (LRFS), regional relapse-free (RRFS), and metastasis-free survival (MFS), specific (SS) and overall survival (OS). In pre-treatment and follow-up consultations, skin, urinary and sexual toxicities were investigated using CTCAEv4.0 classification, International Prostate Symptom Score (IPSS) and International Index of Erectile Function 5-items (IIEF-5). Dosimetry data were also analyzed. RESULTS: From 03/2006 to 05/2020, with a median follow-up of 72.4 months [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], 29 pts, mainly T1 (75.9%) and N0 (89.7%), underwent MHB. Eleven (38%) and 18 pts (62%) received MHB as adjuvant or definitive treatment respectively. Five-year LRFS, RRFS, MFS, SS and OS were 82%, 82%, 89%, 88% and 73% respectively. Six patients (20.7%) experienced local relapse and underwent salvage penectomy leading to a penile preservation rate of 79.3%. Acute skin toxicity was reported 1 month after MHB, with 28% G1, 66% G2 and 6% G3. Late skin complications were telangiectasia for 5 pts (17%) and necrosis for 3 pts (10.3% requiring hyperbaric oxygen therapy). Comparing pre- and post-treatment status, no significant change was observed for skin appearance, IPSS and IIEF-5. CONCLUSION: MHB represents an efficient first line conservative treatment option for early penile cancers. Oncological outcome and late toxicity profile appear encouraging. However, larger-scale cohorts with longer follow-up are needed to more accurately precise the features of the best candidate to MHB.