Personalized High-Dose-Rate Brachytherapy with Non-Sealed Rhenium-188 in Non-Melanoma Skin Cancer

Abstract

Objectives: Most non-melanoma skin tumors are treated with conventional methods, being the most common surgery. However, satisfactory surgical treatment can be very challenging for patients with large or multiple lesions. In cases where the tumor is located on the face, hands or genital areas, the results may be suboptimal in terms of aesthetics and/or function. A high dose-rate brachytherapy using non-sealed Rhenium-188 was developed to offer a personalized solution for these cases as well as cases where a surgical approach was not preferred. Here we show a retrospective analysis of 43 patients treated with this technique.

Methods: The technique, called dermatological high-dose-rate beta-brachytherapy (DBBR), is a brachytherapy based on a non-sealed beta-emitter embedded in a complex specially-designed acrylic matrix. We use Rhenium-188 as the beta-emitter. This matrix is applied over the tumor, which is protected by a special thin plastic foil avoiding any direct physical contact of the radioisotope with the skin. After the calculated required amount of time, the protective foil with the applied radioactive acrylic matrix is removed. 43 patients (basal/squamous cell carcinomas, BCCs and SCCs) were treated with this technique after histological confirmation of the non-melanoma skin tumor. Patients were then followed up, to evaluate wound healing as well as potential side-effects and recurrences.

Results: 29 BCC and 14 SCC patients were treated with DBBR. 36/42 achieved complete clinical remission with only 1 application (24 BCC, 12 SCC) and 6/42 with 2 applications (4 BCC, 2 SCC); 1 BCC patient was lost to follow-up before wound closing. In 4 of the 6 patients (3 BCC, 1 SCC) treated twice the second treatment was planned due to the thickness of the tumor; in the remaining 2 patients (1 BCC, 1 SCC) the second treatment was needed to treat a recurrence at the border of the previously treated area. No side effects were reported. Wound healing was complete in 34-180 days (average 65 days, median 53) for all 42 patients that were followed-up. An average follow-up of 288 days (after one or two treatments) showed no single recurrence (42 patients).

Conclusions: DBBR is a very promising alternative for treatment of BCCs and SCCs for all cases in which a surgical approach is not recommended or accepted by the patient.