Malignant masses in the therapeutically irradiated breast

Mammography is of value in following the response of malignant masses after radiation therapy. Clinical error in evaluating mass size may be considerable, particularly in large breasts or breasts that are contracted and firm. Mammograms of 40 patients treated primarily with irradiation for breast cancer, taken from 3 weeks to 130 months after treatment, were reviewed. The malignant mass markedly diminished or disappeared after radiation therapy in most patients. The rate at which such changes occur is temporally related to the irradiation. Residual radiographically or clinically identifiable mass may persist even in sterilized cancers. Scarring and/or distortion occur frequently. The necessity for mammographic evaluation to determine tumor response and possible recurrence is emphasized, and a mammographic schedule is suggested to facilitate follow-up.