The Cure of Rhabdomyosarcoma BA 1112 with Fractionated Radiotherapy

The experimentally determined time-dose isoeffect relationship for cure of the rat rhabdomyosarcoma BA 1112 is presented. In marked contrast to what might be anticipated for a tumor of cells showing unusually prominent Elkind-type recovery (Dq = 870 rads for hypoxic cells), there is little change in the TCD50 for fractionation courses of as many as ten separate treatments. A mathematical model making use of the previously established radiobiological parameters of this tumor and containing a provision for reoxygenation of initially hypoxic tumor cells during the fractionated treatment successfully predicts the observed time-dose relationship.