Unconventional fractionation in clinical radiotherapy

Radiotherapy with decreasing individual tumour doses has been used in treatment of lung metastases and carcinomas. Treatment given with this unconventional schedule is more effective than conventional radiotherapy based upon equal doses and equal intervals. Tumours could be classified into 2 groups according to the shrinkage rate. In the group shrinking more rapidly, tumours totally disappeared in most instances; furthermore in most instances, tumours in this more responsive group could be identified because in the week after the first fraction they had already started to shrink.