Abstract
Nineteen patients were treated for carcinoma of the alimentary tract by Nd : YAG laser photocoagulation for one of various reasons. Palliative treatment aiming at relief of a carcinoma-induced stenosis was performed in one patient with esophageal carcinoma and in three patients with gastric carcinoma. Although satisfactory relief of the stenosis was achieved in only one of the four patients, we would like to think that no definite conclusion can be drawn from such a small number of cases. In another patient with Borrmann I-type rectal carcinoma, curative treatment by Nd : YAG laser was deployed along with piecemeal polypectomy for tumor reduction. The laser treatment proved on autopsy-the patient having deceased due to cerebral infarction four months later-to have effected a radical cure. Endoscopic Nd : YAG laser treatment was selected rather than surgery on the grounds of the small size of one elevated early esophageal carcinoma and one ha-type early gastric carcinoma. In both these cases local cure was effected as was proven by follow-up endoscopic biopsies which showed no malignant cells at 12 and 18 months, respectively, after laser therapy. Four cases of elevated and eight of depressed early gastric carcinoma were treated by Nd : YAG laser rather than surgically for reasons of either the high operative risk involved or the patient's having refused to undergo an operation. Local cure seems to have been achieved in the four former and three of the latter cases on the evidence of biopsies taken from the sites of the healed laser-induced ulcers, which showed no carcinomatous cells at 12 to 18 months. The five remaining cases with depressed early carcinoma did, however, within six months of follow-up, reveal evidence of carcinomatous growth and required additional treatment. That carcinomatous cells appear during followup would seem to suggest their inadequate elimination by laser irradiation. Possible causes for this are 1) insufficient laser radiation of the lesion, 2) failure to determine the exact extent of the lesion during laser endoscopy, and 3) difficulty in aiming the laser at lesions on the posterior wall of the gastric body. The first cause we consider to be a merely technical error. The second is an as yet unresolved problem of Nd : YAG laser technology which is moreover not compensated by a specific anti-tumor effect as in the case of the HPD-Argon dye laser system. The third we consider to be an urgent technical problem calling for a speedy solution-namely the improvement of endoscopes used in laser treatment and/ or the development of a still finer optical fiber for introducing the laser beam into the GI-tract.
