[The interstitial photocoagulation with laser light of liver tumors]

Interstitial laser photocoagulation (ILP) is a recent interventional procedure performed under US or CT guidance which is capable of inducing thermal necrosis in solid tumors. We have used this technique for about 2 years to treat primary and secondary liver cancers.

Thirty-five patients, 20 of them with liver metastases and 15 with HCC, have been examined: 59 lesions in all, ranging in diameter 10 to 65 mm. Forty-nine lesions have been followed-up for at least 2 months and 25 for at least 6 months. The treatment was performed positioning one to six (18-21 G) modified Chiba needles in the lesions to be treated, according to their sizes, under US or CT guidance. The optical fibers (400-800 mu) were then inserted and the Laser was fired to administer 1,000 Joule/session, with 5-10 W power range. The US and CT patterns of the ILP-treated lesions are reported.

Dynamic CT examinations 2 months after treatment showed complete tumor destruction in 77.5% of the lesions. The best results were obtained in the lesions < 3 cm phi; in particular, 32/38 lesions (84.2%) < 3 cm and with at least 2 months' follow-up exhibited complete necrosis, as did 6 of 11 lesions (54.6%) over 3 cm phi. When residual tumor tissue was demonstrated, further ILP sessions were useless. We observed only few complications which resolved spontaneously in all cases.

At present, ILP remains an experimental procedure: further studies on larger series of patients and comparison with the results of other interventional procedures are needed to confirm its efficacy in treating primary and secondary liver cancers.