胃癌に対する HpD 光化学治療の適応と限界

抄録

Thirty-eight early gastric cancer in 35 patients and two advanced ones considered poor risks for surgery were treated with HpD photodynamic therapy (HpD-PDT). The stage and depth of cancer was assessed by endoscopy. These 37 patients are consist of 26 males and 11 females. The distribution of ago was from 54 to 87 with a mean of 71 years old. Their follow-up periods ranged from one year to seven years and one month (Table 1) Three mg/kg of Photofrin I or 1.3-2.5mg/kg of Photofrin II was in jected intravenously, and about 50 hours later, the entire lesion plus a 5mm width of marginal mucosa was irradiated with an argon dye later through a single quartz fiber. The irradiation was delivered at 300mW·5 minutes/cm², which gave a total dosage of 90 joule/cm²(Table 2 and Fig.1). Among these 38 early gastric cancers, 36 were treated with HpD-PDT alone, and local cure was obtained in 13 (59%) out of 22 mucosal carcinomas, and in 8 (57%) out of 14 submucosal ones (Table 8). The lesions which could not be cured with the initial HpD-PDT were t rooted with hot biopsy with electrodiathermy for a small remnant of cancer, or were repeat ed HpD-PDT once more for a wide one. The other two cancers out of 38 were done with HpD-PDT plus hot biopsy in an initial treatment, and local cure were obtained in both. The final cure rate ac cording to the depth of cancer, was 20 (90%) out of 22 in mucosal cancer, and was 10 (63%) out of 16 in the submucosal ones (Table 5). The advanced ones could not be cured with this therapy. Acording to the size of lesion scaled by cm2, the final cure rate of the size of smaller than 3 was 18 (90%) out of 20, that of 3 to 10 was 10 (71%) out of 14, and that of bigger than 10 was two out of four (Table 4). Looking over them by the gross type, the cure rate in elevated type was 7 (88%) out of 8, that of depressed type without ulceration was 11(73%) out of 15 and that of depressed type with ulceration was 12(80%) out of 15 (Table 6). The use of HpD-PDT should be confined t o an early stage, especially the depressed type and the assembled from of superficial elevated type. The protruding type and solitary elevated type can be cured by other methods such as electrodiathermy, Nd: YAG laser with little difficulty. Concerning the relation between dose and response, local cure was obtained with a dosage of more than 60 joule/cm² in mucosal carcinoma, and with that of more than 72 joule/ cm² in submucosal one (Fig. 2). The indication of HpD-PDT is firstly early gastric cancer in poor risk cases, secondly the superficial depressed type and assembled form of superficial elevated type, and thirdly the size of which should be smaller than 10 cm²(Table 8).