Radiation Safety Observations Associated with 177Lu Dotatate Patients.

Lutetium-177 dotatate, marketed under the name Lutathera®, is proving to be a valuable tool for physicians treating patients with neuroendocrine somatostatin-receptive tumors. Treatment consists of four cycles of 7.4 GBq of Lu dotatate infused intravenously over 30 to 40 minutes. This paper focuses on the radiation safety implications of patients undergoing Lu dotatate treatments at two large medical centers in the United States under the manufacturer's Expanded Access Protocol. Radiation safety precautions are described for the treatment of patients to control for radiation exposure and potential contamination. Ideally, the room used for administration should have a toilet, or one that is in close proximity, and covering should be provided to minimize contamination and clean up. The patient will meet the requirements in 10 CFR Part 35.75 for immediate release based on administered activity or measured exposure rate, but will need to be provided with written instruction on how to keep doses to other individuals ALARA. Disposal of the radioactive waste from Lu dotatate therapy can present some hazard control issues due to the long-lived Lu contaminant.Based on our experience, Lu dotatate therapy is an effective outpatient procedure that can safely occur in any hospital procedural room without the need for additional local shielding. Administration can be accomplished safely with attention paid to the administration set-up and proper administration procedures. Exposure to staff or to adjacent areas is minimal.

Lifetime attributable risk of cancer from CT among patients surviving severe traumatic brain injury.

OBJECTIVE: The purpose of this study was to determine the lifetime attributable risk of cancer from CT among patients surviving severe traumatic brain injury. MATERIALS AND METHODS: A retrospective cross-sectional study was conducted with prospectively collected data on patients 16 years old and older admitted with a Glasgow coma scale score of 8 or less to a single level 1 trauma center from 2007 to 2010. The effective dose of each CT examination the patients underwent was predicted with literature-accepted effective dose values of standard helical CT protocols. The lifetime attributable risk of cancer and related mortality incurred as a result of CT were estimated with the cumulative effective dose incurred from the time of injury to a 1-year follow-up evaluation and with the approach established by the Biologic Effects of Ionizing Radiation VII report. RESULTS: The average patient was a 34-year-old man. The median number of CT examinations received during the first 12 months after injury was 20, and the average cumulative effective dose was 87 ± 45 mSv. This resulted in increases in the lifetime incidence of all cancer types from 45.5% to 46.3% and in the lifetime incidence of cancer-related mortality from 22.1% to 22.5%. CONCLUSION: Radiation exposure from the use of CT in the evaluation and management of severe traumatic brain injury causes negligible increases in lifetime attributable risk of cancer and cancer-related mortality. Treating physicians should not allow the concern for future risk of radiation-induced cancer to influence decisions regarding radiographic evaluation in the acute treatment of traumatic brain injury.

Patient release criteria for low dose rate brachytherapy implants.

A lack of consensus regarding a model governing the release of patients following sealed source brachytherapy has led to a set of patient release policies that vary from institution to institution. The U.S. Nuclear Regulatory Commission has issued regulatory guidance on patient release in NUREG 1556, Volume 9, Rev. 2, Appendix U, which allows calculation of release limits following implant brachytherapy. While the formalism presented in NUREG is meaningful for the calculation of release limits in the context of relatively high energy gamma emitters, it does not estimate accurately the effective dose equivalent for the common low dose rate brachytherapy sources Cs, I, and Pd. NUREG 1556 states that patient release may be based on patient-specific calculations as long as the calculation is documented. This work is intended to provide a format for patient-specific calculations to be used for the consideration of patients' release following the implantation of certain low dose rate brachytherapy isotopes.