IGSRT should become a first-line recommendation for patients with early stage NMSCs, particularly for individuals who are poor candidates for or who refuse surgical resection.

Image-guided superficial radiation therapy (Image-Guided SRT, or IGSRT), bested Mohs micrographic surgery (MMS) for individuals with early stage nonmelanoma skin cancers (NMSCs).

The study, which is the first to directly compare two-year recurrence probabilities of image-guided SRT to Mohs,  appears in Clinical and Translational Radiation Oncology and will be featured at the American Society for Radiation Oncology (ASTRO) annual meeting in San Diego.

"The major finding demonstrating a statistically significant improvement in 2-year recurrence probabilities of NMSCs when treated primarily with IGSRT compared to MMS, is a big win for the modern-day Mohs surgeon and the dermatology profession,” says Dr. Daniel J. Ladd, Jr., Mohs surgeon and Chief Medical Officer of SkinCure Oncology, in a news release. “This was observed both in pooled NMSC data and when stratified by histological type ((basal cell carcinoma (BCC), squamous cell carcinoma (SCC)). This suggests that IGSRT should become a first-line recommendation for patients with early stage NMSCs, like BCCs and SCCs, particularly for individuals who are poor candidates for, or who refuse surgical resection. As a physician, having image-guided SRT and Mohs micrographic surgery for patients allows me to offer a comprehensive approach to fully informed consent and medical decision making. After all, it is all about our patients." 

The retrospective cohort study compared the 2-year recurrence probability of early stage NMSCs treated by IGSRT (2,286 lesions) to data on NMSCs treated by MMS (5,391 lesions) via one sample proportion tests. Medical Subject Headings were used to search PubMed for reports of 2-year recurrence probability rates of NMSCs treated by MMS.

IGSRT is well tolerated, and each procedure visit is relatively short. IGSRT results in favorable cosmetic outcomes; reconstructive/scar revision procedures are avoided,  and it eliminates post-surgical complications. It is an option for patients with contraindications to surgery, like certain cardiac conditions or coagulopathies; and, treatment with IGSRT, which is performed by a radiation therapist with physician supervision, can include up to four lesions at one time, and is not constrained by anatomy, the study authors conclude.

"Because IGSRT is noninvasive," Dr. Ladd notes, "it results in favorable cosmetic outcomes with no scarring or need for reconstructive surgery. As reported, this is particularly important, as the greatest incidence of NMSC occurs on sun-exposed areas such as the head and neck, which are cosmetically sensitive."

The authors observe that prior to the invention of Mohs surgery, superficial radiation therapy (SRT) was a standard therapy offered by dermatologists for nonmelanoma skin cancer. It offered excellent toxicity profiles and, at the time, equivalent oncologic outcomes to resection. With the advent of Mohs, however, SRT oncologic outcomes fell significantly behind, and SRT fell out of favor. IGSRT was developed in 2016, and since then, this technology and treatment paradigm has seen a resurgence. Initial results have suggested outcomes that are far improved over SRT, warranting the currently reported robust statistical comparison of IGSRT to Mohs.