Nelson, Kevin L.

Abstract 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 177 Lu dotatate infused intravenously over 30 to 40 minutes. This paper focuses on the radiation safety implications of patients undergoing 177 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 177 Lu dotatate therapy can present some hazard control issues due to the long-lived 177m Lu contaminant. Based on our experience, 177 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.

Object Surgeon and operating room (OR) staff radiation exposure during spinal surgery is a concern, especially with the increasing use of multiplanar fluoroscopy in minimally invasive spinal surgery procedures. Cone beam computed tomography (cbCT)–based, 3D image guidance does not involve the use of active fluoroscopy during instrumentation placement and therefore decreases radiation exposure for the surgeon and OR staff during spinal fusion procedures. However, the radiation scatter of a cbCT device can be similar to that of a standard 64-slice CT scanner and thus could expose the surgeon and OR staff to radiation during image acquisition. The purpose of the present study was to measure radiation exposure at several unshielded locations in the OR when using cbCT in conjunction with 3D image-guided spinal surgery in 25 spinal surgery cases. Methods Five unshielded badge dosimeters were placed at set locations in the OR during 25 spinal surgery cases in which cbCT-based, 3D image guidance was used. The cbCT device (O-ARM) was used in conjunction with the Stealth S7 image-guided platform. The radiology department analyzed the badge dosimeters after completion of the last case. Results Fifty high-definition O-ARM spins were performed in 25 patients for spinal registration and to check instrumentation placement. Image-guided placement of 124 screws from C-2 to the ileum was accomplished without complication. Badge dosimetry analysis revealed minimal radiation exposure for the badges 6 feet from the gantry in the area of the anesthesiology equipment, as well as for the badges located 10–13 feet from the gantry on each side of the room (mean 0.7–3.6 mrem/spin). The greatest radiation exposure occurred on the badge attached to the OR table within the gantry (mean 176.9 mrem/spin), as well as on the control panel adjacent to the gantry (mean 128.0 mrem/spin). Conclusions Radiation scatter from the O-ARM was minimal at various distances outside of and not adjacent to the gantry. Although the average radiation exposure at these locations was low, an earlier study, undertaken in a similar fashion, revealed no radiation exposure when the surgeon stood behind a lead shield. This simple precaution can eliminate the small amount of radiation exposure to OR staff in cases in which the O-ARM is used.

AbstractBackgroundRadiation exposure to the surgeon is a concern in spinal surgery, especially with the increasing popularity of minimally invasive spinal surgery techniques. Three‐dimensional (3D) image guidance used in conjunction with cone beam computed tomography (cbCT) has a theoretical advantage of decreased radiation exposure to the surgeon and operating room (OR) staff. Radiation scatter to the environment immediately surrounding a CT scanner during acquisition of a CT scan is a known entity. This in vivo study measures the radiation exposure to the surgeon when using cbCT registration in 3D image‐guided spinal surgery.MethodsTwo badge dosimeters were worn by the surgeon (EWN), one on the right waistband of the surgeon's scrubs and the other located over the thyroid area during 25 consecutive spinal surgery cases in which cbCT was used in conjunction with 3D image guidance. No lead protection was worn by the surgeon. The cbCT device was used for registration of the anatomy and to confirm adequate instrumentation placement. The surgeon stood behind a clear lead shield in the same location during every spin of the cbCT device. After the 25th case, the badge dosimeters were sent to the radiology department for analysis.ResultsOverall, 63 cbCT spins were accomplished in 25 patients. A total of 228 screws were placed into spinal levels spanning from C2 to the ileum. No complications resulted from instrumentation placement or the use of image guidance.Analysis of both badge dosimeters revealed 0 millirem (mRem) exposure.ConclusionsOur study demonstrates that no radiation exposure to the surgeon occurs in cbCT‐based, 3D image‐guided spinal surgery procedures. Additionally, radiation scatter does not result in surgeon radiation exposure during patient registration if the surgeon stands behind a lead shield 10 feet from the cbCT device and not in direct line with the opening of the cbCT tube. Copyright © 2011 John Wiley & Sons, Ltd.