A follow-up examination of 444 persons treated with x-rays for tuberculous cervical adenitis was performed to determine if the risk for hyperparathyroidism (HIT) following radiation exposure can be related to the age at treatment, the dose of x-rays, or the sex of the patient. The overall incidence of H I T was 14%. There was no definite age-dependent difference in 'susceptibility to the induction of HIT. The doses of radiation among the 63 subjects who developed HPT ranged from 0.6 to 45.7 Cy (604570 rad). There was a statistically significant positive correlation between the dose of radiation and the probability of developing HPT. After doses of 14 Cy (1400 rad) or more 29% of the subjects had developed HIT. After neck irradiation women had twice the relative risk of men of developing HIT. This sex ratio was lower than in the series of nonirradiated HPT patients treated at the same institution during the time of the Cancer 56:1529-1533, 1985. follow-up study.
T HAS BEEN demonstrated that there is an increased in-I cidence of hyperparathyroidism (HPT) following external irradiation of the neck region.'** The results of a previous study suggested a correlation between the dose of radiation and the risk of developing HPT. That series was too small to allow statistical analyses.'
In a series of 391 patients surgically treated for HPT between 1974 and 198 1, we found the sex ratio of women to men among irradiated HPT patients, excluding those traced by follow-up, to be 6: 1, and 3.4: 1 in nonirradiated patient^.^ The irradiated patients in that series had been treated at many institutions for various disorders. As we do not know the sex distribution of the irradiated populations from which these patients were derived, the series does not allow any conclusions to be drawn about the sex-related risk of developing HPT after neck irradiation.
We have now collected data from 444 subjects, 281 women and 163 men, who had been irradiated for cervical tuberculous adenitis at one institution. This large series permits statistical analyses of the correlation between the radiation dose, age at treatment, sex of the patient, and the probability of developing HPT after neck irradiation.