1996 San Juan de Dios radiotherapy accident

The radiotherapy accident in Costa Rica occurred within the Alcyon II radiotherapy unit at San Juan de Dios Hospital in San José, Costa Rica.

An accidental overexposure of radiotherapy patients treated during August and September 1996 was detected.

During the calibration process done after the change of 60Co source on 22 August 1996, a mistake was made in calculating the dose rate, leading to severe overexposure of patients.

In the course of the accident, 114 patients received an overdose of radiation and 13 died of radiation-related injuries.

[1][2] In 2001, the radiophysicist whose mistake caused the radiation overdoses was charged with 16 culpable homicides and sentenced to six years in prison.