Photodynamic therapy for sarcoma pulmonary metastases: a preclinical toxicity study.

BACKGROUND

Intraoperative pleural and interstitial PDT accompanying resection may reduce peripheral micrometastatic foci and preclude lobectomy when applied to hilar lesions.

MATERIALS AND

METHODS

Fourteen beagles were used to determine the safety and histologic changes resulting from PDT. Photosensitizers HPPH (0.3 mg/kg) or Photofrin (2.0 mg/kg) were administered i.v. 48 hours prior to thoracotomy and light delivery. At thoracotomy interstitial or pleural light was given. They underwent necropsy at eight and 30 days.

RESULTS

The significant toxicitities occurred with pleural PDT using high dose HPPH (15 & 30 J/cm2) including pyrexia, elevated WBC and CPK, and respiratory distress. However, using single beam pleural surface treatment all light doses for HPPH and Photofrin (5-40 J/cm2) were tolerated with depths of treatment effect up to 10 mm with HPPH.

CONCLUSION

Histologic and clinical changes associated with interstitial and pleural PDT were acceptable after dosimetry was adjusted. PDT holds promise as an adjuvant treatment for sarcoma pulmonary metastases.