The CivaSheet: The new frontier of intraoperative radiation therapy or a pricier alternative to LDR brachytherapy?

When defining the balance between tumor control and toxicities, considerable caution must be exercised near organs with serial functional subunits, such as the spinal cord and named nerves, because of the potential for irreversible damage. In such challenging clinical scenarios, the highly targeted nature of intraoperative radiation therapy (IORT) may offer a viable option to improve patient outcomes. Traditionally, IORT refers to the delivery of focused radiation immediately after surgical resection via intraoperative electron beam, superficial x-ray, or highor low-dose rate (HDR; LDR) mesh techniques. Although these methods provide a theoretical benefit because of their capacity for precise radiation delivery through a single procedure, several disadvantages have limited their use in clinical practice. Both electron and x-ray IORT require the costly installation of an intraoperative linear accelerator. The large size and customization limitations of currently available IORT electron cones make targeting of complex anatomic surfaces difficult. HDR IORT requires the use of an HDR remote after-loader and a shielded operating room. When using LDR mesh, source orientation and spacing can be difficult to maintain during mesh customization, leading to large dose inhomogeneities. The CivaSheet (CivaTech Oncology Inc., Durham, NC), an implantable unidirectional palladium-103 (Pd-103) planar low-dose brachytherapy device, overcomes many of these shortcomings and offers a novel radiation delivery approach in sites with close proximity to organs at risk. The CivaSheet consists of individual Pd-103 sources encapsulated in an organic polymer and embedded within an 8 mm × 8 mm grid that consists of a flexible bio-absorbable substrate. The sources are shielded on one side with gold to attenuate the dose to only one tenth of the total dose. The CivaSheet received approval from the U.S. Food and Drug Administration in 2014 for planar LDR brachytherapy. A recent abstract demonstrated that, in a patient with a pelvic side wall malignancy, the device offered significant reductions in dosage to critical structures, such as the bowel and bladder, compared with conventional LDR. Here we describe the case of a 78-year-old man with persistent squamous cell carcinoma of the left axilla after external beam radiation therapy (EBRT) who underwent surgical resection and CivaSheet implantation.