A. Popovtzer1, Y. Fleissig2, N. Kurman3, A. Mizrachi4, E. Rosenfeld3, G. Feliciani5, S. R. Bellia6, D. Silvern3, A. Sarnelli5, J. Feldman1, J. Elia2, N. Hirshoren2, and R. Den7; 1Hadassah Medical Center, Jerusalem 91120, Israel, 2Hadassah Medical Center, Jerusalem, Israel, 3Rabin Medical Center, Petach Tikva, Israel, 4Department of Head and Neck Surgery , Rabin Medical Center, Beilinson Campus, Petah Tikva, Israel, 5ISTITUTO SCIENTIFICO ROMAGNOLO PER LO STUDIO E LA CURA DEI TUMORI- IRST, MEDICAL PHYSICS DEPARTMENT, Meldola (FC), Italy, 6IRCCS - ISTITUTO SCIENTIFICO ROMAGNOLO PER LO STUDIO E LA CURA DEI TUMORI- IRST, RADIOTHERAPY DEPARTMENT,, Meldola (FC), Italy, 7Alpha Tau Medical, Jerusalem, Israel
Purpose/Objective(s): The standard treatment for oral cavity squamous cell carcinoma (OSCC) has remained surgery for decades and the accepted approaches are often challenging in older patients. The present research evaluated the efficacy and safety of Diffusing Alpha-Emitter Radiation Therapy (DaRT) as a novel method of treating these solid tumors using alpha-particle interstitial radiotherapy. Materials/
Methods: Data from patients with OSCC were collected from three prospective clinical trials at multiple medical centers in Israel and Italy. Tumor response was determined by Response Evaluation Criteria in Solid Tumors guidelines (RECIST v1.1). Safety was assessed according to Common Terminology Criteria for Adverse Events (CTCAE) V5.0. Results: Twenty-three patients (11 female and 12 male) were treated with DaRT for OSCC across the participating clinical sites. Subjects were elderly, with a mean age of 85 (range 60-102), with 78% having a cardiovascular history and 43% with diabetes. Tumor locations included the lip, tongue and buccal mucosa, with mean baseline tumor volume of 3.1 cubic cm. All procedures were performed under local anesthesia in an outpatient setting. The objective response rate was 100% for the 19 tumors which were evaluated (the remaining cases were withdrawn prior to evaluation due to unrelated serious adverse events, withdrawal of consent or election to proceed with alternative therapy), with 18 (95%) showing a complete response and 1 (5%) a partial response. All related adverse events were Grade 1 or 2. Conclusion: All patients tolerated DaRT therapy with 95% complete response rate and favorable safety profile. DaRT has the potential to serve as a treatment for OSCC, particularly in the elderly population.
