Initial experience and lessons learned with implementing Lutetium-177-dotatate radiopharmaceutical therapy in a radiation oncology-based program.

PURPOSE: To assist radiation oncology centers in implementing Lutetium-177-dotatate (177Lu) radiopharmaceutical therapy for midgut neuroendocrine tumors. Here we describe our workflow and how it was revised based on our initial experience on an expanded access protocol (EAP). METHODS: A treatment team/area was identified. An IV-pump-based infusion technique was implemented. Exposure-based techniques were implemented to determine completion of administration, administered activity, and patient releasability. Acute toxicities were assessed at each fraction. A workflow failure modes and effects analysis (FMEA) was performed. RESULTS: A total of 22 patients were treated: 11 patients during EAP (36 administrations) and 11 patients after EAP (44 administrations). Mean 177Lu infusion time was 37 min (range 26-65 min). Mean administered activity was 97% (range 90-99%). Mean patient exposures at 1 m were 1.9 mR/h (range 1.0-4.1 mR/h) post-177Lu and 0.9 mR/h (range 0.4-1.8 mR/h) at discharge, rendering patients releasable with instructions. Treatment area was decontaminated and released same day. All patients in the EAP experienced nausea, and nearly half experienced emesis despite premedication with antiemetics. Peripheral IV-line complications occurred in six treatments (16.7%), halting administration in 2 cases (5.6%). We transitioned to peripherally inserted central catheter (PICC)-lines and revised amino acid formulary after the EAP. The second cohort of 11 patients after EAP were analyzed for PICC-line complications and acute toxicity. Nausea and emesis rates decreased (nausea G1+ 61%-27%; emesis G1+ 23%-7%), and no PICC complications were observed. FMEA revealed that a failure in amino acid preparation was the highest risk. CONCLUSION: 177Lu-dotatate can be administered safely in an outpatient radiation oncology department.

Calibration setting numbers for dose calibrators for the PET isotopes (52)Mn, (64)Cu, (76)Br, (86)Y, (89)Zr, (124)I.

For PET radionuclides, the radioactivity of a sample can be conveniently measured by a dose calibrator. These devices depend on a "calibration setting number", but many recommended settings from manuals were interpolated based on standard sources of other radionuclide(s). We conducted HPGe gamma-ray spectroscopy, resulting in a reference for determining settings in two types of vessels containing one of several PET radionuclides. Our results reiterate the notion that in-house, experimental calibrations are recommended for different radionuclides and vessels.