Malignant Intracranial Neoplasms Following Radiation Therapy for Acromegaly

In a review of the records of 104 acromegalic patients, 4 cases of malignant intracranial neoplasms were found, all of which had arisen within or adjacent to tissues exposed to irradiation during treatment. This study was initiated to determine, if possible, the role of irradiation in the evolution of these malignant tumors. Material All the 104 patients (59 women; 45 men) with acromegaly, whose records were reviewed, were seen between 1931 and 1961: 100 at the University of California Medical Center and 4 privately (M.B.G.). Treatment consisting of irradiation, surgical procedures, or both had been carried out at the Medical Center in most instances. A few patients had been treated elsewhere; several, in whom the process was inactive, required no therapy other than hormone replacement for deficiencies of target organs. Suppressive hormone therapy was attempted in a few cases. The length of follow-up observation totalled 750 patient years (Table I). At the beginning of 1961, 37 patients were known to be dead, 48 were living, and the status of 19 was unknown. Of the 104 patients, 75 received irradiation to the pituitary. Figure 1 summarizes the data on these 75. The sex, approximate age at onset, duration of disease, time of irradiation and years of follow-up observation are noted for each. Similar data on the 29 patients not irradiated are summarized in Figure 2. Case Reports Case I:2 A 24-year-old woman was first seen in January 1922 with complaints of headaches and increase in the size of the hands and feet. Menses had ceased two years previously. Acromegalic facial changes, exophthalmos, diminished visual acuity, bilateral optic atrophy, and bitemporal hemianopsia were apparent. The sella turcica was enlarged and the posterior clinoid processes were eroded. Because of acute deterioration of vision, a transsphenoidal hypophysectomy was performed (1922).3 Vision improved temporarily, but within a few months became worse. The size of the sella and the visual field defect increased further. A mass 2 cm. in diameter was removed by a second transsphenoidal hypophysectomy.3 In 1931 the headaches returned and vision further diminished. Except for a questionable episode in 1942, the acromegaly was quiescent from 1935 on. Radiation therapy was administered from 1922 to 1942, either in repeated single treatments or in short courses. Through 1925, no information is available regarding the quality of the radiation or the dose delivered. Most of the subsequent therapy was given with 250-kvp equipment. Through 1925, it was given via bilateral temporal fields. Later, temporal, nasal, occipital, and vertex fields were alternated. Although no visible skin change developed in the other areas, the temporal fields eventually showed marked atrophy of the skin and subcutaneous layers. The accumulated dose to the temporal fields cannot be estimated but must have been very large. A soft-tissue mass appeared near the right mastoid process in February 1952.