Abstract
Objective: The first clinical trial in humans with skin and oral cavity squamous cell carcinoma (SCC) was performed in order to evaluate the effect of a unique intratumoral alpha radiation-based tumor ablation treatment termed Diffusing Alpha-emitters Radiation Therapy (DaRT).
Methods: Radium-224 loaded sources (DaRT seeds) were inserted into solid tumors and released by recoil short-lived alpha-emitting atoms (Rn-220, Po-216, Pb-212, Bi-212, Po-212, Tl-208). These atoms disperse in the tumor and spray it with highly destructive alpha radiation. The decay products diffuse in the tumor mass to a distance of at least 5 mm.
Results: A feasibility and safety clinical study is ongoing and currently 28 patients were treated at the Rabin Medical Center (Israel) and IRST (Italy). Patients with histopathologic confirmed skin or head and neck SCC, and tumor size ≤5 centimeters in the largest diameter, were enrolled. Treatment was delivered based on a CT-simulation pretreatment plan. The seeds (1 cm long and 0.7 mm in diameter), each carrying a dose of 2 μCi, were placed up to 5 millimeters from each other. CT was used in order to confirm the position of the radioactive seeds. Two weeks after implantation the seeds were removed, and six weeks after treatment a CT scan was performed to assess the effect of treatment. Study results are available for 18 cases that were treated per protocol and reached the 30-day follow-up period. Age of the patients ranged from 60 to 102 years (median 80 years). Ten patients had oral cavity SCC and 18 were diagnosed with cutaneous SCC. Thirteen subjects were treated within prior radiation failure fields (radiation dosage >60Gy). All tumors responded to the treatment; 13 tumors exhibited a complete response and five tumors showed partial response. No major toxicity was noted.
Conclusions: In this first feasibility and safety human study we demonstrated that alpha-based treatment (DaRT) resulted in enhanced radiobiologic potential. Furthermore, the treatment was effective against radioresistant SCC tumors without any major side effects.
Citation Format: Aviram Mizrachi, Aron Popovtzer, Eli Rosenfeld, Ran Ben-Hur, Itzhak Kelson, Yona Keisari. Treatment of squamous cell carcinoma by alpha radiation-based brachytherapy (Alpha DaRT) [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr A10.
RSS Feeds