Fetal Tolerance to Roentgen Rays

Susceptibility of the human fetus to the harmful effects of radiation has long been a matter of conjecture. Recorded observations indicate that the result of heavy dosage is unpredictable but may be disastrous. The occasional opinion that the small dose customarily used in diagnostic roentgenology may be harmful has not been confirmed by clinical experience. While there are extensive reports as to the harmful effects of large dosage, we are seldom presented with evidence that such effect is not inevitable. The case to be reported here is that of a human fetus subjected to a large dose of roentgen rays without apparent damage. Mrs. G. E., aged 29, discovered a slightly painful small hard mass in her left breast on July 5, 1944, attributed to injury sustained on July 4. A radical mastectomy was performed on Aug. 19, and the anatomical diagnosis was adenocarcinoma. The regional nodes were involved, and surgery was followed by irradiation of the tumor bed, axilla, and neck. The family history was negative for neoplastic disease or mental deficiency. During a ten-year period the patient had had six normal pregnancies, with all children living and well, ranging in age from nine to two years. She was again pregnant, the calculated approximate date of conception being June 1. At the time of mastectomy, therapeutic abortion was urged but was declined. Low-back pain, beginning late in September, soon became severe and continuous. A roentgenogram made on Oct. 14 demonstrated an osteolytic lesion in the sacrum and right ilium. Surgical interruption of the existing pregnancy was again recommended and refused. It was considered that survival of the maternal patient for the full period of gestation was unlikely without treatment, or would be attended with too great distress. From Oct. 14 to Oct. 27, a dose of 1,500 r, measured in air, was delivered to each of two 15-cm. portals. The beams were directed dorsoventrally and ventrodorsally, respectively, with a half-value layer of 0.9 mm. of copper. The calculated mid-pelvic depth dose was 900 r. Not only was the pain poorly controlled, but the bone lesion actually increased in size during and after treatment (Figs. 1 and 2). From Jan. 13 to Jan. 17, 1945, additional radiation was directed to the dorsal field, thereby adding 375 r at the center of the pelvis. On Feb. 16, pregnancy was terminated with the delivery by cesarean section of a male child having an entirely healthy appearance. Soon thereafter the osteolytic lesion in the pelvis of the mother healed; other lesions appeared in the skull and bones of the upper extremities, and these responded well to small x-ray doses. From May until October 1945, the patient was free from pain, was able to resume physical activity, and seemed well. In November there was evident liver metastasis and death occurred on Jan. 5, 1946.