Tu1188 EFFICACY OF PHOTODYNAMIC THERAPY WITH A NEW PHOTOSENSITIZER (TALAPORFIN SODIUM) AS A SALVAGE TREATMENT FOR LOCAL FAILURE AFTER DEFINITIVE CHEMORADIOTHERAPY FOR ESOPHAGEAL CANCER.

Abstract

Esophageal cancer is one of the most common cancers worldwide. Chemoradiotherapy (CRT) is one of the curative treatments for esophageal cancer in patients with unresectable tumors or those who refuse surgery. However, local failure after CRT is a problem. An alternate treatment in such patients is photodynamic therapy (PDT). Talaporfin sodium, a second-generation photosensitizer, is rapidly cleared from the skin and requires a shorter sun-shade period (2 weeks). Furthermore, the depth of effect is expected to extend to deeper layers of the muscularis propria because of the excitation wavelength of the diode laser. In this study, we evaluated the efficacy of PDT with talaporfin sodium for local failure after CRT for esophageal cancer. Patients with histologically proven local failure limited within the muscularis propria after radiotherapy (RT) of 50 Gy or more for esophageal cancer were eligible.The PDT procedure commenced with intravenous administration of a 40 mg/m2-dose of talaporfin sodium, followed by laser irradiation at a 664-nm wavelength 4 to 6 hours after administration. The fluence of the diode laser was set at 100 J/cm2. The local efficacy was classified based on endoscopic evaluation as local complete response (L-CR). The L-CR rate per patients was the primary endpoint of this study. The secondary endpoints were local progression-free survival (L-PFS), and overall survival (OS). 14 patients with a total of 20 lesions received additional laser irradiation. The median total laser exposure dose was 210 (range: 100–800) J. 11 patients with a total of 16 lesions achieved L-CR after PDT (L-CR rate: 80.0%). The L-CR rate of T1 failure lesions was 92.3% (12/13), whereas the L-CR rate of T2 failure lesions was 57.1% (4/7). The median follow up period was 11.6 months (range: 1.3-38). 3 non-CR patients with PDT developed progression and one of them died at 697 days after PDT. 1 CR patient developed local recurrence 94 days after PDT and received salvage surgery. The other 2 patients died due to other cancers at 113 days, and 326 days after PDT. Therefore, 6 events were confirmed for the L-PFS curve at present, and the median L-PFS was 326 days. As for OS, only 3 events described earlier were observed, and thus the median survival is undefined for this follow up period. Chest pain was occurred in 4 patients (28.6%), while fever (38°C) occurred in 2 patients (14.3%). No skin phototoxicity was observed. 2 patients (14.3%) developed an esophageal perforation and were managed with non-surgical measures. There was no case of treatment-related death. PDT using talaporfin sodium and a diode laser is a safe and curative salvage treatment for local failure after CRT for patients with esophageal cancer. The possibility of esophageal perforation after PDT should be considered for longer than 1 month post-therapy.