Is tumor necrosis necessary to achieve a response in refractory tumors treated with intralesionally photoactivated talaporfin sodium (IPTS)?

Abstract

8238 Background: Response to IPTS therapy, an investigational method proposed for treating refractory, bulky tumors, may differ from the typical necrosis pattern seen with radio-frequency ablation. To determine whether tumor necrosis is required to achieve a response to IPTS therapy, I performed the following analysis of the CT imaging findings from a Phase I safety study of IPTS. Methods: 21 patients with refractory, bulky tumors of varying histologic types were treated with IPTS by means of a light-emitting diode (LED) array placed percutaneously using CT guidance. The treatment zone was limited to a region within the tumor border. Contrast-enhanced CT studies were acquired on days 0, 7, 14, and 42. 19 of the 21 patients (90%) enrolled completed the study. Each tumor was assessed serially by measuring its longest dimension and by noting the extent of tumor necrosis as compared with the baseline measurement. Assessments were performed jointly by the principal investigator (PI) and a radiologist at each s...