According to the Skin Cancer Foundation, more than 3.5 million cases of nonmelanoma skin cancers (NMSCs) are treated in the United States annually, making it the most commonly encountered malignancy.
Ajay Bhatnagar, MD, MBA,
According to the Skin Cancer Foundation, more than 3.5 million cases of nonmelanoma skin cancers (NMSCs) are treated in the United States annually, making it the most commonly encountered malignancy.1Historically, treatment has involved surgical excision, radiation, and/or topical chemotherapy, which can require many treatments and can sometimes be disfiguring. A new portable electronic brachytherapy (EBT) device is now providing patients with a noninvasive, outpatient treatment option that has been associated with fewer treatments and excellent response and cosmesis.2
“The primary treatment option for basal cell carcinoma and squamous cell carcinoma is surgery, however, there are segments of the NMSC population for whom EBT is a good alternative,” said Ajay Bhatnagar, MD, MBA, medical director, 21st Century Oncology of Arizona, toTargeted Oncology. “Specifically, it is a good alternative for patients with lesions in anatomically challenging locations, such as the ears, nose, scalp, and neck; patients who are on blood thinning medications; and patients who may have conditions that can cause difficulties in wound healing,” he added.
The EBT device, known as the Xoft Electronic Brachytherapy (eBx) System, enables the clinician to administer surface brachytherapy without using radioactive isotopes or requiring a megavoltage linear accelerator; thus, it can be used in any clinical setting under the supervision of a radiation oncologist, and it can be easily transported within a facility or between multiple locations, including rooms without a vault. Unlike traditional radiation therapy, which can require daily treatments for up to 6 weeks, eBx requires only two visits a week for 4 weeks, and patients can resume normal activities immediately after treatment.
The system improves tumor targeting using a lightweight (>150 g) direct contact surface applicator and a flexible clamp, enabling the applicator to be oriented to the desired location on the target lesion. Use of a low-energy miniaturized X-ray source minimizes exposure to healthy adjacent tissues, and reduced shielding requirements enable healthcare providers to remain near the patient during treatment. Furthermore, the faster fall-off rate spares patients’ healthy tissue and organs.
“The Xoft System is the only FDA-cleared electronic brachytherapy system that has been used to treat more than 10,000 NMSC patients and is supported by positive 4-year clinical data,” said Bhatnagar, who recently presented data on Xoft’s eBx System at the American Academy of Dermatology Annual Meeting.
Dr. Bhatnagar’s study included 200 patients (mean age, 77 years; range, 52 to 102 years) with 297 NMSCs who were treated with eBx between July 2009 and June 2014. Treatment involved placing a thermoplastic mask around the lesions to protect adjacent healthy tissue and then holding the eBx’s surface applicator above the lesion to deliver radiation. Healthcare providers could select between 10-, 20-, 35-, and 50-mm surface applicators, enabling use of an applicator that would allow for complete coverage of the target lesion while providing an acceptable margin. All patients received same-dose fractionation (ie, 40.0 Gy at 2 fractions per week) at a prescription depth of 3-mm for most lesions; if a thick lesion was identified, computed tomography scanning was used to determine prescription depth.
After a mean follow-up of 16.5 months (range, 1-63 months), all 297 lesions showed a complete response, with only one recurrence. Cosmesis was also excellent for more than 90% of lesions, and no patients experienced poor cosmesis. The most commonly reported acute toxicities at 1 month included rash dermatitis (82%), pruritus (27%), and hyperpigmentation (2%), all of which resolved within 1 year. The only late toxicity, occurring at or after 12 months, was hyperpigmentation (2%), with no grade 3 or higher toxicities observed.
The eBx system is also being used to treat breast and gynecologic cancers. More information on using EBT to treat these cancers and NMSCs can be found at theXoft website.