[Patient #1], with localized prostate cancer, had an ultrasound directed transperineal implant with 60
I-125 seeds on 1/12/2010. The total activity implanted was 20.4 mCi. Final dosimetry was based on a
CT scan performed on 2/16/2010. This revealed a D90 of 8400 cGy which was lower than the prescribed dose of 14500 cGy. The patient and referring physician were notified and the patient then received supplemental external beam irradiation of the prostate with 3000 cGy delivered between 3/11/2010 and 4/08/2010. The patient is currently doing well with minimal treatment related symptoms.
[Patient #2], with localized prostate cancer, had an ultrasound directed transperineal implant with 66 Cs-131 seeds on 1/12/2010. The total activity implanted was 186 mCi. Final dosimetry was based on a CT scan performed on 2/16/2010. This revealed a D90 of 6500 cGy which was lower than the prescribed dose of 11000 cGy. All seeds were accounted for in the final review. However, careful review of the isodose lines revealed adequate coverage of the involved areas of the prostate. The patient and referring physician were notified and the prescribing physician indicated that additional treatment was not necessary.
[Both] events occurred due to unexpected displacement of the seeds in an inferior (caudal) direction.
[The licensee] continues to use preplanning for all prostate brachytherapy patients with careful direct supervision of needle and seed placement. Six (6) patients have been treated with brachytherapy at Bristol Hospital since January 2010 and the final dosimetry has been acceptable for all.
A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.