Efficient clinical workflow for intraoperative electron radiation therapy with a mobile electron accelerator

Intraoperative radiotherapy (IORT) is designed to deliver a precise dose of ionizing radiation to a tumor or tumor bed after surgical resection. The IORT procedure can deliver targeted radiation to the tumor with increased normal tissue sparing, hence improving the efficacy of the procedure when nearby organs at risk (OAR) can be mobilized out of the field thus maximizing the therapeutic ratio. This report presents the institutional experience of establishing the IORT program, highlighting our workflow improvement, quality assurance (QA), and dosimetric practices. The IntraOp® Mobetron® 2000 can be used to irradiate a target using megavoltage (MV) electron beams of energies 6 MeV, 9 MeV, and 12 MeV at a high dose rate of 1000 cGy/minute. Mayo Clinic Florida (MCF) has a dedicated and well-shielded QA suite adjacent to the operating room (OR) for both treatment preparation and daily QA purposes. The Mobetron is docked over the target assembly with the help of the autodocking software. The IORT workflow in the OR is assisted by the Mobility (IntraOp Medical Corp., Sunnyvale, CA) system which ensures safe and efficient maneuvering of the Mobetron. The treatment planning and beam control using the treatment console is done from inside the shielded QA room. Since its commissioning in 2016, 138 patients have been treated with IORT using the Mobetron ® 2000, at MCF. The efficacy of IORT has been utilized in the treatment of locally advanced and recurrent sites like pancreas, rectum, retroperitoneal sarcoma and some gynecologic cases. A well-planned housing of the Mobetron, adjacent to the OR, and its timely upgrades has resulted in an efficient and safe IORT workflow.