Tumor fixation of bleomycin labeled with 57 cobalt before and after cryotherapy of bronchial carcinoma.

The combined effect of cryotherapy and chemotherapy was studied in 12 patients with bronchial carcinoma. Radiolabeled (57 Co) Bleomycin (BLM) was injected intravenously and initial detection was carried out with a gamma-camera. Plasma half-life and clearance of 57 Co-BLM, as well as tumor/normal tissues ratios were calculated. The same protocol was performed 15 days later immediately after cryotherapy. A mean increase of 30% of radiolabeled BLM was found in the tumor area after cryotherapy, and pharmacokinetic data were significantly different after cryotherapy. The vascular component of cryodestruction offers an explanation for these results, with trapping of the anticancer drug in the tumor and immediately surrounding area due to vascular stasis. It seems that chemotherapy may be more effective after cryotherapy, and a multicenter study is in progress to evaluate the association of cryo-chemotherapy in France.