Treatment of Primary Breast Cancer Using PDT

This is a phase I / IIa study recruiting patients diagnosed with primary breast cancer. Patients who have chosen mastectomy or wide local excision as their surgical option will be included. Patients will have a pre therapy MRI followed by photodynamic therapy. PDT involves intravenously injecting the photosensitizer Verteporfin (Visudyne) drug. This drug makes the tumour sensitive to light. A non-thermal light will then be shone in the tumour which brings about tissue necrosis (destruction). Although the drug dose will remain the same, the light dose will be escalated depending on patient response in accordance to a predefined algorithm (see section) to achieve a zone of necrosis of 12mm or a plateau of necrosis with incremental increase in light dose. An MRI will be performed immediately prior to the scheduled surgery. Pre and post PDT MRI changes will be correlated with the histological findings on the excised breast specimen. Should the minimum light dose for 12mm necrosis be established recruitment will continue until 12 patients have received this dose. These 12 patients will provide sample data on the size of tumour and area of necrosis detected by MRI and histology to enable sample size (power) calculations for future studies of PDT in primary breast cancer. This is a dose escalation study involving a minimum of twelve and a maximum of forty patients.