By Dr. Ajay Bhatnagar
Bhatnagar A. Electronic Brachytherapy for the Treatment of Nonmelanoma Skin Cancer: Results at 3 Years. Int J Radiat Oncol Biol Phys 2013;87:S65.
By Dr. Ajay Bhatnagar
Brachytherapy 12 (2013)
Skin Surgery Medical Group, Inc.
San Diego, CA
Cancer Treatment Services Arizona
Casa Grande, AZ
Xoft Skin eBx
Why Xoft Skin eBx?
The Xoft® Electronic Brachytherapy (eBx®) System® enables the clinician to administer surface brachytherapy without the use of a radioactive isotope or a megavoltage linear accelerator, making surface treatments more accessible at locations where no vault exists and eliminating treatment delays by expanding access to radiation therapy.
eBx simplifies the surface radiation process with improved targeting of the tumor site using a direct contact applicator and a flexible clamp. The lightweight surface applicator (less than 150g) can be precisely oriented to the desired location on the patient (target lesion). With the reduced shielding requirement of eBx, the physician can remain near the patient. Furthermore, faster dose fall-off of the low-energy miniaturized X-ray source minimizes exposure to healthy adjacent tissues.
- Targeted non-melanoma skin cancer (NMSC) treatment results in excellent (>90%) cosmesis¹
- Painless, non-invasive option for select patients
- Ideal for challenging anatomic locations
Compared to electron beam therapy, the Xoft System surface brachytherapy system allows a more precise set-up with continuous monitoring, which might allow smaller margins with smaller treatment fields, potentially leading to fewer treatments of higher doses with similar cosmetic results. The delivered field with the Xoft System source has sharp fall-off edges (the 80–20 penumbral transition width is under 3 mm versus 10–12 mm of MeV electrons)1, which allows field sizes as small as 1 cm in diameter. The applicator has been designed to deliver homogenous dose over 90% of the target area. With the ability to plan the field accurately within 1 mm of the desired treatment site, a smaller area can be used to deliver the treatment dose. A target area between 1 cm and 5 cm in diameter over a range of treatments allows for optimal dose application. With the combination of ease of placement, precision of dose delivery and small applicator size, almost any externally accessible area on the body can be treated (for example buccal mucosa of the oral cavity)2.
Treating with eBx
eBx is administered under the direction of a radiation oncologist. In cooperation with the dermatologist, the radiation oncologist will determine the amount of radiation needed and the physicist will ensure that the radiation is delivered as prescribed. eBxcan be delivered on an outpatient basis in a room with reduced shielding requirements. Treatment regimen and prescription depend on tumor size, type, depth, patient age, prior treatments and other criteria. During radiation therapy, the surface applicator is connected to the Xoft System Controller. The treatment site is prepared with a flexible shield that is cut to shape to surround the target area and protect the adjacent non-target tissues. A miniaturized X-ray source is placed in the applicator and energized to deliver radiation for a few minutes. At the completion of the treatment, the X-ray source is turned off. All devices are removed in between treatment fractions.
Xoft Skin eBx
Xoft Skin eBx is a scalable and modular solution that streamlines implementation and management of a skin electronic brachytherapy program. This unique end-to-end offering provides practices with all the components necessary to perform skin
eBx treatments. Comprised of hardware, software, management services and support, Xoft eBx provides radiation oncologists with state-of-the-art technology, expert clinical guidance, and unparalleled customer support - all from the market leader in electronic brachytherapy.
The modular design of the Xoft Skin eBx solution allows practices to customize the comprehensive set of products and services to best fit their needs. Hardware components may be acquired through standalone purchase, or integrated as part of a more comprehensive services program.
Axxent SPX Controller: Specifically designed for surface treatments, this highly mobile, easily transported unit features a streamlined design for improved patient positioning and comfort. FDA cleared for multiple indications; the SPX controller can be retrofitted to accommodate practice growth into other indications such as breast IORT and vaginal brachytherapy.
Axxent X-ray Source: Proprietary isotope-free source technology allows surface treatments in virtually any setting with minimal shielding. The fast dose fall-off of the 50 kV source minimizes exposure to adjacent healthy tissues and organs and allows medical personnel to remain in the room with the patient.
Axxent Surface Applicators: With sizes ranging from 10mm to 50mm, Xoft offers the widest range of applicators on the market, providing clinicians with maximum flexibility in treating a variety of lesion sizes. In addition, the proprietary flattening filter at the apex of the cone ensures even dose distribution across the lesion surface.
Axxent Hub: This cloud-based platform software solution allows clinicians to manage patient volumes and treatments, organize patient dose prescriptions for multiple lesions, and develop best practices, policies and procedures for a skin eBx program. The Axxent Hub is a repository that enables documentation, quality assurance and source management to improve efficiency and reduce risk of systematic errors in patient care. Superbills and daily Charge Capture summary reports streamline billing and office workflow.
Xoft Skin eBx assists practices with the management services necessary to successfully implement a skin eBx program, including:
- Technical staff
- Program management and operational logistics
- X-ray Source calibration as required
- Documentation and billing support compliance and improve workflow efficiency
- Regular Quality Reviews to maintain highest level of patient care
Xoft is committed to providing Skin eBx customers with industry-leading customer service and support. Our professional services
organization guides each practice through the program development process from beginning to end, including:
- IT/Technical Support and integration with existing systems
- Management of annual hardware and software maintenance contracts
- Source contract administration
- Training of office staff and clinicians
Facts About Skin Indications
One in six Americans develops skin cancer at some point with over a million cases annually in the U.S.3,4 Most patients are diagnosed with non-melanoma skin cancer (NMSC) with basal cell carcinoma being the most common in 80% and squamous cell carcinoma representing 20%. The majority of lesions are located on sun-exposed areas like face, backs of hands and neck. According to the NCCN guidelines5 radiation therapy is a treatment option for primary NMSC treatment or secondary in case of positive margins post-surgical. Keloid scarring is another indication that is most suitable for surface brachytherapy. Surgical excision of keloid formation is usually only effective 20–50% of the time with surgery alone. With combined surgery and radiation therapy, the treatment is successful over 80% of the time.6
1 Perez CA, Brady LW. Principles and Practice of Radiation Oncology. Third edition. Lippincott, Williams & Wilkins: 1998.
2 Sabbas AM, et al. HDR Brachytherapy with Surface Applicators: Technical Considerations and Dosimetry. Technology in Cancer Research & Treatment 2004. Vol 3(3); 259–267.
3 National Cancer Institute 2008: http://www.cancer.gov/cancertopics/types/skin
4 American Cancer Society, Cancer Facts and Figures 2008: http://www.cancer.org/downloads/STT/2008CAFFfinalsecured.pdf
5 National Comprehensive Cancer Network: http://www.nccn.org/professionals/physician_gls/f_guidelines.asp
6 Lawrence WT. In search of the optimal treatment of keloids: report of a series and a review of the literature. Ann Plast Surg 1991;27:164–78.