Results of d + T fast neutron irradiation on advanced tumors of bladder and rectum.
From November, 1975 to November, 1981, around 400 patients were irradiated with 14 MeV d + T fast neutrons at the Antoni van Leeuwenhoek Hospital in Amsterdam. Special interest was focused on inoperable tumors of bladder and rectum. During the pilot phase of the study 47 patients were treated, mostly via two parallel opposed ports with dosages that ranged from 18 to more than 22 Gy. Although persistent local control was achieved in 23 patients (48%), 14 patients (29%) died of severe complications. By the introduction of a six field technique, the fatal complication rate could be reduced significantly. Since May 1978 patients were randomized in a three arm trial, using two dose levels on the neutron site. The preliminary results of a group of 91 patients show a similar survival in the three treatment arms with a somewhat better local control rate for high dose neutrons. An attempt was made to estimate RBE values for tumor control and normal tissue reactions by comparing the data for neutron irradiation with the data obtained with photons on a similar group of patients. From the values derived it must be concluded that the gain for neutron irradiation on these tumors in the pelvis will be negligible.
D002986:Clinical Trials as Topic; D005214:Fast Neutrons; D005720:Gamma Rays; D006801:Humans; D009502:Neutrons; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy; D012004:Rectal Neoplasms / Q000532:radiotherapy*; D012062:Relative Biological Effectiveness; D001749:Urinary Bladder Neoplasms / Q000532:radiotherapy*; D014965:X-Rays