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.
Keywords: ABS, American Brachytherapy Society; Brachytherapy; CCAFU, Cancer Committee of the French Association of Urology; CT, computerized tomography; CTCAE, common terminology criteria for adverse events; CTV, clinical target volume; Conservative treatment; DFS, disease-free survival; DNR, dose non-homogenity ratio; EAU, European Association of Urology; EBRT, external beam radiotherapy; EQD2, equivalent dose in 2Gy fractions; GC-SFRO, Groupe Curiethérapie/Société Française de Radiothérapie Oncologique; GEC-ESTRO, Groupe Européen de Curiethérapie/European Society for Therapeutic Radiation and Oncology; HDB, high-dose brachytherapy; IIEF, international index of erectile function; IPSS, international prostate symptom score; LC, local control; LDR, low-dose rate; MDFS, metastatic disease-free survival; MFU, median follow-up; MHB, multicatheter interstitial high-dose rate brachytherapy; MMS, Mohs micrographic surgery; MRI, magnetic resonance imaging; NCCN, national comprehensive cancer network; OS, overall survival; PDR, pulse-dose rate; PET, positron emission tomography; PP, penile preservation; Penectomy; Penile cancer; RC, regional control; SCC, squamous cell carcinoma; SFRO, Société Française de Radiothérapie Oncologique; SS, specific survival; TNM, tumor node metastasis.
© 2021 The Author(s).