INTERSTITIAL LASER TREATMENT OF MALIGNANT-TUMORS - INITIAL EXPERIENCE

This is a prospective pilot investigation of interstitial laser treatm ent, Twelve patients mere treated at 13 sites: seven patients had meta static or primary liver cancer (with a total of 21 tumour nodules), tw o had pancreatic carcinoma and four patients had disease at other site s, Treatments were performed with an Nd-YAG laser, using a high power (6 or 10 W), short-time (5 min) technique or a feedback system for tem perature regulation at low power (3 W) for 12-16 min, Treatment with h igh power invariably resulted in rapid carbonization of tissue, which may have contributed to the post-operative death in one patient, The l ocal effect of treatment could be evaluated in 13 hepatic tumours (1.0 -10 cm in diameter): 100% necrosis was seen in five and >50% necrosis in the remaining eight, Two tumours mere eradicated, five became small er, and six remained unchanged in size or showed continued growth, Tre atment removed or alleviated symptoms in 7/8 symptomatic patients. The feedback system made it possible to avoid carbonization and allowed b etter control of the tissue temperature, The main problem with either method was to monitor tissue changes in real time, and ultrasonography was found to be of little help in this respect. It is concluded that interstitial laser treatment is a promising method for treatment of tu mours, Further development should focus on real-time monitoring and in creased volume effect without carbonization.