[Pion radiotherapy of unresectable soft tissue XXXX at the Swiss Institute for Nuclear Research].

@entity1 @entity242 @entity5 @entity3 @entity299
The Swiss Institute for Nuclear Research SIN at Villigen is one of the three centres in the world (LAMPF, Los Alamos; TRIUMF, Vancouver) where pion therapy is possible. A dynamic, @entity5 conforming spot scan technique for the treatment of @entity5 has been in use since November 1981. With this technique with a favorable integral dose distribution, curative irradiation also of advanced @entity5 in the retroperitoneum and pelvis is possible. Only at SIN, the treatment of non-resectable soft tissue @entity242 with pions is part of the clinical program. Between 1983 and 1985 totally nine @entity1 were treated, 1/9 with three manifestations, 1/9 with palliative intent. In 20 fractions over five weeks (four fractions a week) total doses of 30 to 36 Gy (90% isodose) were applied. In a follow-up period of eleven to 43 months (median 18 months) only 1/10 @entity5 manifestations treated with greater than or equal to 30 Gy failed locally. The two-year survival rate (Kaplan-Meier) is 56%. @entity3 were the cause of death in 3/5 @entity1 , 1/5 @entity299 , 1/5 local @entity5 progression. Even though 9/11 @entity5 were located in the retroperitoneum or pelvis, no radiogenic morbidity of the bowel was found. These preliminary results stimulate the intensification of this clinical program. 1986 the same number of @entity1 with non-resectable soft tissue @entity242 was treated as in the whole period 1982 to 1985 before.
