RTHP-01. PENTOXIFYLLINE AND VITAMIN E FOR THE TREATMENT OF RADIATION NECROSIS AFTER STEREOTACTIC RADIOSURGERY

Abstract

Abstract BACKGROUND The combination of oral pentoxifylline (Ptx) and vitamin E (VitE) has been used to treat radiation-induced fibrosis and soft tissue injury. A 2008 study showed an average decrease in edema with the use of Ptx + VitE in 11 patients with suspected radiation necrosis after stereotactic radiosurgery (SRS). Here we review outcomes in patients prescribed Ptx + VitE at our institution for the treatment of radiation necrosis. METHODS 48 patients were included in this analysis. All patients were treated with SRS, had evidence of radiation necrosis, and had MR imaging before and after starting Ptx + VitE. The radiation oncologist’s impression of the imaging in the electronic medical record was used to score response to treatment. Official radiology reports were also reviewed. RESULTS 43.8% of patients showed evidence of improvement, 18.8% showed no change, and 25% showed worsening radiation necrosis on imaging after starting Ptx + VitE. One patient had a mixed response; 5 patients (10.4%) had disease progression. The median time to response assessment after starting Ptx + Vit E was 3.17 months. 9 patients progressed significantly on Ptx + VitE and required Bevacizumab, hyperbaric oxygen therapy or surgery. Patients who had multiple lesions treated with SRS were less likely to show improvement on imaging after Ptx + VitE (p=0.037). 34 patients were also prescribed dexamethasone, either before (7), with (16), or after starting (11) Ptx + VitE. Use of dexamethasone was not associated with improved response to Ptx + VitE (p=0.471). 3 patients stopped Ptx + VitE due to reported side effects. CONCLUSION Ptx + VitE appears safe for the treatment of radiation necrosis, but randomized data are needed to assess efficacy.