Therapeutic exposures were ascertained through abstraction of medical and radiation therapy records of each participant by using a standardized protocol. For patients who received radiation therapy, the full therapy records were copied and sent to the Radiation Dosimetry Center to allow for detailed dosimetry in selected studies. For external-beam treatments, the following details were abstracted from the records: dates of the beginning and end of each course of radiation therapy records of each participant by using a standardized protocol. For patients who received radiation therapy, sent to the Radiation Dosimetry Center to allow for detailed dosimetry in selected studies. For external-beam treatments, dates of the beginning and end of each course of radiation therapy, type of machine, energy of radiation, anatomic location of treatment fields, blocking used (if applicable), and radiation dose delivered to the tumor. For brachytherapy treatments,the treatment time, anatomic location of radiation sources, and dose delivered to the tumor. For each patient in a study, we estimated the absorbed dose at the organ or site of interest for the at-risk time period appropriate to the study outcome. Dose calculations were based on a three-dimensional mathematical phantom using measurements in a water phantom