Quantification of subcutaneous fibrosis after combined photon neutron therapy

Subcutaneous fibrosis is intensified for neutron therapy compared with photon irradiation. It can be a dose limiting factor. Quantification of subcutaneous fibrosis is possible using CT scans and measuring the tissue density in Hounsfield units. With this technique the time dependent development of fibrosis after neutron irradiation was determined in ten patients, who had been treated for recurrent recto-sigmoidal tumors.