High-dose-rate brachytherapy for facial skin cancer: Outcome and toxicity assessment for 71 cases.

PURPOSE: In France, the reference technique for skin cancer was low-dose-rate brachytherapy (BT) delivered via iridium wire. At the end of their commercialization in 2015 we have replaced them by high-dose-rate (HDR) BT via interstitial catheters. We assessed efficacy and tolerance as soon as this technique was implemented. METHODS AND MATERIALS: Patients received 7 Gy on the first day, followed by 8 × 4 Gy over the next 4 days for exclusive BT and 9 × 4 Gy over 5 days for post-operative BT. RESULTS: Sixty-six patients of median age 81 years received a total of 58 primary BT and 13 post-operative BT for non-melanoma facial skin cancers. Implantation was without difficulty. Median follow up was 15.3 months. Two patients died of intercurrent diseases before first follow up. For the others, 98.5% showed complete response and 3% local recurrence after a median of 20.5 months. Four patients had grade 3 acute dermatitis and three patients had grade 3 mucositis. All the Grade 3 toxicities were resolved within 3 months. A late significant hypopigmentation occurred in 4 patients. CONCLUSIONS: HDR BT is efficient and well-tolerated with good cosmetic results. HDR catheters are similar with iridium wires in terms of technical difficulty.

Effect of bladder distension on doses to organs at risk in Pulsed-Dose-Rate 3D image-guided adaptive brachytherapy for locally advanced cervical cancer.

PURPOSE: To evaluate the impact of bladder distension on doses to organs at risk in patients treated with 3D image-guided adaptive pulsed-dose-rate (PDR) brachytherapy (BT) for locally advanced cervical cancer. METHODS AND MATERIALS: Twenty-two patients who had previously been treated by external beam radiation therapy (EBRT), underwent BT treatment planning to a pelvic MRI (or a CT scan in case of contraindication) after their bladder was filled with 100 cc of physiological saline (full bladder). This was immediately followed by a CT scan after emptying of the bladder. A fusion of these two examinations was conducted, and the dosimetry was duplicated for the study with an empty bladder. Equieffective doses of 2 Gy per fraction from EBRT and BT of bladder/rectum/sigmoid colon/small bowel were compared. RESULTS: A full bladder condition was found to be non-inferior in terms of the bladder D2cc (a difference of -0.9 Gy; 97.5% CI [-∞; 2.6]), and it resulted in a reduction in the bladder D0.1cc (p = 0.038). Bladder expansion resulted in a significant reduction of maximum doses received by the small bowel, both in terms of the D0.1cc (51.2 Gy vs. 63.4 Gy, p < 0.001) and the D2cc (48.5 Gy vs. 53.6 Gy, p < 0.001). A negative correlation was seen between the difference in the small bowel D2cc and the body mass index; (r = -0.55; p = 0.008). No differences were noted in regard to doses to the rectum and sigmoid colon. CONCLUSIONS: Bladder distension with 100 cc of physiological saline can reduce maximum doses received by the small bowel without the alteration of the doses received by the other organs at risk during a 3D image-guided adaptive PDR BT for locally advanced cervical cancer. However, the maintenance of a predefined bladder volume is difficult to achieve with PDR BT, whereas it could be easily managed before each session in case of high-dose-rate BT.