HPPH and PDT for Pleural Malignancy

Photodynamic therapy (PDT) is an experimental treatment that uses a drug called a photosensitizer or photosensitizing agent and light to kill cells. When photosensitizers are exposed to a specific wavelength of light, they produce a form of oxygen that kills hearby cells. The appeal o PDT in oncology has been that the photosensitizer is retained in tumor tissue for longer periods of time compared to normal tissues. This reported differential of photosensitizer retention in tumor compared to normal tissues provides the potential for an enhanced therapeutic index minimizing normal tissue toxicity has prompted an interest in studying PDT as a cancer treatment and is a proposed treatment for a variety of malignancies and pre-malignant conditions. The proposed study is a Phase I trial of photodynamic therapy (PDT) for the treatment of patients with pleural malignancies. To participate patients must be 18 years of age or older, must have a histological diagnosis of pleural malignancy, must have disease limited to the hemithorax (one side of the chest), must be medically suitable for resection, and must have a ECOG performance status of 0-2. Patients who have received prior surgery, gene therapy, or combination chemotherapy will also be permitted if it has been at least 30 days since the last treatment. Patients will be given HPPH, by intravenous injection prior to surgery. HPPH is a chlorine based photosensitizer used along with PDT to prevent recurrence of tumors following surgical removal. After successful tumor removal light from a tunable dye laser or diode laser will be administered. The starting dose of PDT will ve administered 24 or 48 hours prior to surgical resection. Red light will be used to illuminate the entire thoracic cavity. If adequate removal of the tumor cannot be performed , the patient will not be eligible to receive light therapy. In parallel laboratory studies, biopsies of tumor and normal tissues will be taken from the resection specimens. Uptake of HPPH will be measured in tumor and normal tissues and tumor to normal tissue ratios of HPPH will be determined. Assessment of molecular signaling including EGFR, Akt, and MAPK will be made in tumor prior to and after light delivery. Patients will simultaneously be enrolled on a companion protocol in which the 2-nitroimidazole, EF5 will be administered to determine tumor oxygen concentration. Finally, non-invasive measurements of optical properties, tissue oxygenation, photosensitizer uptake, and blood flow will be made intraoperatively. After hospital discharge patients will be seen routinely in outpatient Thoracic Surgery and Radiation Oncology Department clinics. These follow visits will occur one month., two months later and every three months of the first 24 months to assess treatment related toxicities. A history and physical examination, laboratory and a CT or MRI of the chest will be performed every 3 months. A follow-up chest x-ray will be obtained as clinically indicated. An assessment of toxicity will be made at each follow-up visit. After 24 months, follow-up should be scheduled as clinically indicated.