Photodynamic therapy for management of refractory hemorrhagic radiation proctitis

Background: Radiation proctitis can result in transfusion-dependent bleeding refractory to topical or conventional cautery therapies. Surgical intervention carries considerable morbidity and mortality. Photodynamic therapy (PDT) is an attractive alternative modality whereby injection of a photosensitizing drug preferentially targets aberrant blood vessels. Subsequently, light activation of the drug results in thrombosis and obliteration of the neovessels. Aim: To assess the efficacy of PDT in the management of transfusion-dependent hemorrhagic radiation proctitis. Methods: PDT was applied to 3 male patients (ages 69, 76, and 82) s/p radiotherapy for prostate cancer. All were chronically anemic, transfusion-dependent, with radiation-induced telangiectasias and stigmata of recent bleed from radiation proctitis. All had failed traditional therapies including Nd:YAG laser, argon laser, heater probe and even experimental topical formalin therapy. Mean duration of bleeding before PDT was 13 months (range 8-22). A photosensitizing drug, hematoporphyrin derivative, was injected i.v. at a dosage of 1.75-2.0 mg/kg. Forty-eight hrs later, phototherapy was conducted on the telangiectatic areas using a cylindrical diffusing fiber passing through a flexible sigmoidoscope. A light dose of 180 J/cm² was delivered at an output of 400 mW and wavelength of 630 nm produced from an argon-pumped tunable dye laser. Endoscopy was repeated 24 hrs post PDT to assess the degree of telangiectatic obliteration. Mean follow-up was 5 months (range 2-8). Results: Endoscopy 24 hrs post PDT demonstrated at least 50% obliteration of telangiectasias in all patients. A significant reduction in quantity and frequency of bleeding was observed. The mean hemoglobin level pre and post PDT was 8.2±0.4 g/dl and 11.1±0.6 g/dl respectively. Pre PDT, these patients required on average 1-2 units of blood monthly. Post PDT, 2 patients have been free of transfusions for a follow-up period of 5-8 months. One patient requiring blood transfusions every 2 weeks pre PDT has received a single transfusion 3 days post PDT and none since for a follow-up period of 2 months. All patients subjectively reported an improvement in quality of life in view of minimal bleeding, reduction or elimination of blood transfusions, and enhanced stamina. Conclusions: PDT appears to be effective in controlling bleeding in patients with severe refractory radiation proctitis. In these challenging cases, PDT may be an alternative to surgical intervention. This study continues to enroll patients to evaluate long term benefits and risks.