A Novel Form of Breast Intraoperative Radiation Therapy With CT-Guided High-Dose-Rate Brachytherapy: Results of a Prospective Phase 1 Clinical Trial

Utility of CT imaging in a novel form of high‐dose‐rate intraoperative breast radiation therapy

“…We evaluated the utility of CT imaging use during PB‐IORT for the treatment of breast cancer and found that the use of cross‐sectional imaging resulted in applicator repositioning and/or dose modifications in the majority of patients. The incorporation of intraoperative CT in PB‐IORT allows for surgical adjustment and subsequent confirmation of appropriate applicator placement as well as three‐dimensional treatment planning . This is in contrast to the methods of CB‐IORT utilized in the TARGIT and ELIOT trials, which did not employ routine intraoperative imaging.…”

“…Importantly, at both locations, the CT images were used by the radiation oncology teams to calculate the dose and optimize customized delivery of 12.5 Gy in a single fraction to the planning target volume (distance of 1 cm around the balloon surface) with an iridium 192 HDR brachytherapy source. This dose was selected to increase the dose at a depth of 1 cm as compared to alternative low‐energy kV IORT techniques while maintaining an acceptable dose at the surface of the applicator . This dose was tumoricidal to a depth of 1 cm from the applicator surface.…”

“…This novel breast IORT technique delivers high‐dose‐rate (HDR) brachytherapy through a multi‐lumen applicator placed into the lumpectomy bed at time of breast conserving surgery. Computed tomography (CT) is obtained, allowing the surgeon to alter placement of the applicator within the cavity while also facilitating treatment planning by the radiation oncologist . The use of HDR brachytherapy allows for the delivery of 12.5 Gy to tissue 1 cm from the applicator's surface, which is significantly higher than the 5–7 Gy delivered during CB‐IORT .…”

“…The use of HDR brachytherapy allows for the delivery of 12.5 Gy to tissue 1 cm from the applicator's surface, which is significantly higher than the 5–7 Gy delivered during CB‐IORT . A 28‐patient phase I safety and feasibility trial was completed, and 75 patients have been accrued into the ongoing phase II trial which was designed to evaluate the long‐term efficacy of PB‐IORT . The purpose of the current study was to report on the utility of CT imaging in PB‐IORT, both in regard to surgical applicator placement and in adjustments to dosimetry planning, for the first 103 patients treated in these prospective trials.…”

Intraoperative radiation therapy for breast cancer patients: current perspectives

“…PB-IORT combines high dose rate brachytherapy and CT imaging to deliver a single dose of customized radiation at the time of lumpectomy and has been shown to be safe and feasible 12. An ongoing Phase II trial has been designed to assess the efficacy in comparison to conventional TARGIT style IORT.…”