LCD L40189: Superficial Radiation Therapy (SRT) for the Treatment of Nonmelanoma Skin Cancers (NMSC)

Compliance with the provisions in this LCD may be monitored and addressed through post payment data analysis and subsequent medical review audits.

History/Background and General Information

Nonmelanoma skin cancers (NMSC) such as squamous cell carcinoma (SCC) or basal cell carcinoma (BCC) are a type of keratinocyte carcinoma and are the most common malignancies reported in the United States of America(U.S.). 1-3 In 2015, Rogers et al. analyzed claims data from 2006 through 2012 for total claims filed in both the Total Claims Data Set and the Medicare Limited Data Set and found that NMSC was the most common malignancy treated based upon CPT codes. In addition, they noted that the incidence of diagnosed NMSC increased 35% from 2006 through 2012. 2 Unfortunately, the prevalence of NMSC is generally not reported or tracked by national cancer registries. 3 However, the total number of procedures for skin cancer treatment in the Medicare population increased by 13% from 2,048,517 in 2006 to 2,321,058 in 2012. 2 Even though the exact prevalence of NMSC may be unknown, the American Cancer Society estimates that 5.4 million basal and squamous cell skin cancers are diagnosed each year in the U.S. occurring in approximately 3.3 million people. 3

There are multiple modalities available for the treatment of cutaneous NMSCs. Predication of treatment is often based upon the most reasonable alternative that will give the highest likelihood of cure with the least associated morbidity. Such treatment options include electrodessication and curettage, topical chemotherapeutic agents, simple surgical excision, complex surgical excision with or without frozen section, micrographically oriented histographic surgery (Mohs), external beam radiation therapy (EBRT), and SRT including electronic brachytherapy (EBT). 4,5,7-13 More recently, there have been some reports of combining the use of high-resolution ultrasound (HRUS) imaging with SRT or EBT in order to guide delivery and assess lesion reduction; the effectiveness of this additional modality is currently under active investigation. 14-19

According to the National Comprehensive Cancer Network ® (NCCN ® ) and the American Academy of Dermatology Association (AAD) guidelines, treatment is based upon the stratification of SCC and BCC into risk factors based upon the likelihood of recurrence. 4,5,8,9 Per NCCN ® guidelines for BCC, 4 the stratification elucidated below should be used to determine the treatment for local BCC based on the following risk factors for recurrence (any high-risk factor places the patient into the high-risk stratification group): low-risk BCC and high-risk BCC.

Similarly, NCCN ® stratification guidelines for local SCC or SCC in situ are based on risk factors for recurrence and are stratified into low-risk, high-risk and very high-risk. 5 Risk category assignment should be based on the highest risk factor present. The high-risk group has elevated risk of local recurrence; the very-high-risk group has elevated risk of local recurrence and elevated risk of metastasis. Deep invasion for SCC is defined as invasion beyond the subcutaneous fat OR >6 mm (as measured from the granular layer of adjacent normal epidermis to the base of the tumor, consistent with the American Joint Committee on Cancer (AJCC) Staging Manual, 8th Edition). 20 The very high-risk SCC is not amenable to SRT, and the depth is measured before any preoperative curettage or other treatment to the lesion.

Narrow excision margins, due to anatomic and functional constraints, are associated with increased recurrence rates with standard histologic processing. Complete margin assessment such as with Mohs or peripheral and deep en face margin assessment (PDEMA) is recommended for optimal tumor clearance and maximal tissue conservation per NCCN ® guidelines for both SCC and BCC. 4,5 Very high-risk SCC should be treated with surgical excision with PDEMA or Mohs micrographic surgery (MMS) with/without adjuvant RT based upon consultation with a radiation oncologist per NCCN ® guidelines OR EBRT. 5

Current published and recommended guidelines exist from NCCN ® , AAD, the American Society of Radiation Oncology (ASTRO), and the American Brachytherapy Society (ABS). Recommended treatment of cutaneous NMSC is based upon a consortium of experts and peer-reviewed literature. 4-11

The focus of this LCD will pull information from literature including published societal guidelines and published peer-reviewed articles. No changes are recommended for currently approved indications for EBRT and MMS for the treatment of NMSC. Peer-reviewed, published evidence on SRT and the subset on EBT will be utilized to help establish coverage limitations for these modalities in the Medicare population.

BCC is the most common form of human cancer with a continued increase in annual incidence and is closely followed by SCC in the U.S. 1-3,8,9 While several options for treatment exist, the majority of NMSCs are treated surgically, either with a traditional surgical excision or MMS.

SRT has also been a long-standing, optional treatment by dermatologists and radiation therapists but had been relegated to a second line treatment option for patients who were not surgical candidates or who refused surgical treatment. In addition, there are no prospective or randomized clinical trials (RCTs) in the peer-reviewed literature that compare the outcomes in recurrence rates (long-term 5 years or more, short-term less than 2 years) between MMS or surgical excisions and SRT. In addition, with the advent of newer SRT technology, the reported recurrence rates have improved and are near the MMS rates although there is no consistent reporting of the histology sub-types and comparison of sub-groups with the higher risk NMSCs that are typical of MMS procedures. 10-15,21-24 Furthermore, several authors have purported to using HRUS guided SRT and HRUS guided EBT as being more effective than SRT or EBT alone, although there are no randomized clinical studies or prospective studies to show that the additional use of high-resolution ultrasound guidance (HRUS) improves the short-term and long-term recurrence rates. 14-16

SRT utilizes x-rays or photons to deliver electromagnetic energy to cells that are rapidly dividing in order to stop mitosis. SRT machines deliver low energy Kilovoltage (kV) in the range of 50 to 150 kV per treatment. The machines used to deliver superficial treatment spare the deeper structures and are ideal for treating cutaneous malignancies. 13 EBT is a variation of SRT except that a high dose x-ray source is placed directly into a skin applicator close to the surface and provides a homogenous dose pattern in the treatment area to a specified depth. EBT also delivers low-energy radiation at a high dose rate through an application that is placed on the skin typically less than 120 kilovoltage photons (kVp) as compared to traditional brachytherapy. 13,25 Traditional isotope-based brachytherapy administers radiation therapy within or in contact with the body. EBT does not require the application of a radioactive source. Both SRT and EBT can be produced by commercially available devices 10,13 and are being used in the outpatient dermatology office or radiation oncology setting.

Covered Indications

The medical record documentation must support the medical necessity for the use of SRT as the primary modality for treatment of the NMSC.

If the beneficiary meets all the criteria as outlined in the LCD, the use of SRT is considered reasonable and necessary for the following conditions:

• The presence of a low-risk cutaneous BCC or high-risk BCC as per NCCN ® , ASTRO, and AAD guidelines with documentation that the patient is a nonsurgical candidate, 4,8,10 OR

• The presence of a low-risk cutaneous SCC or high-risk SCC as per NCCN ® , ASTRO, and AAD guidelines with documentation that the patient is a nonsurgical candidate, 5,9,10 OR

• The presence of a cutaneous SCC in situ as per NCCN ® , ASTRO and AAD guidelines with documentation that the patient is a nonsurgical candidate. 5,9,10

Examples of nonsurgical candidates are patients where the surgery would cause loss of function, would result in significant morbidity, poor cosmesis in an anatomically sensitive area (e.g., ears, nose, lips, or eyelids), or when after documentation of shared decision making the patient refuses surgery as a treatment option.

Limitations

• Use of HRUS to guide SRT delivery and to assess lesion reduction during the superficial radiation treatment protocol is not considered reasonable and necessary and is not supported by literature. 10

• Based upon the consensus of the literature and the recommendations of the AAD, ASTRO and ABS, the use of EBT for the treatment of NMSCs is not considered reasonable and necessary at this time. There is insufficient long-term efficacy and safety data to support the use of electronic surface brachytherapy. 12,13,26

Limitations for SRT

The following are considered not reasonable and necessary:

• First line treatment option in surgical candidates.

• The use of SRT for the treatment of advanced BCC and SCC.

• The use of SRT for the treatment of patients with NMSCs who have contraindications to RT.

• Cutaneous tumors arising in previously irradiated fields or where overlapping fields would be expected.

• Cutaneous SCC with size greater than 4 cm. 5

• Cutaneous BCC with size greater than 4 cm. 14

• Cutaneous NMSCs with depth greater than 6 mm. 5,14,19

• Cutaneous NMSCs with aggressive morphology. 2 7,28

• Cutaneous tumors with perineural or perivascular invasion as sole treatment option. 4,5,10

• Very high-risk SCC. 5-7,9,10

Provider Qualifications

For purposes of Centers for Medicare and Medicaid Services (CMS) reasonable and necessary services are ordered and furnished by qualified personnel. Services will be considered medically reasonable and necessary only if performed by appropriately trained providers.

A qualified physician for this service is defined as follows: training and expertise must have been acquired within the framework of an accredited residency and/or fellowship program in the applicable specialty/subspecialty (i.e., Radiation Oncology OR by a qualified dermatology program and the dermatologist has didactic training and clinical experience in radiation treatment).

Free standing facilities (office or clinic), hospital-based practices and mobile delivery units affiliated with a Place of Service (POS) must meet federal and state local radiation protection guidelines in regard to patient safety and quality assurance as well as the physician supervision requirements. It is expected that all personnel (e.g., radiation oncologist, other qualified physician, radiation/medical physicist, radiation technologist and radiation assistant) involved in administering, supervising, and treating patients for the indications outlined in this LCD meet the regulations set forth for the state, for Medicare and the Nuclear Regulatory Commission (NRC), as applicable.

A literature search was conducted using the following key terms: SCC, BCC, SRT, EBT, RT, Mohs, surgical excision of skin cancer, IGSRT, IGEBT, recurrence rates and societal guidelines including NCCN ® , AAD, American College of Mohs Surgery (ACMS), ASTRO and ABS. Additional sources included PubMed and ECRI datasets. The literature search included published peer-reviewed literature and published societal guidelines within the last 25-30 years with greater emphasis placed upon literature from the last 15 years. Retrospective studies involving larger sample were included in order to gather as much evidence as possible, although RCTs and prospective RCTs were more useful in the analysis of current evidence. Case reports and case series were excluded due to low quality of evidence. Poster presentations and unpublished reports were not included in the analysis. Published societal guidelines and recommendations were considered in the analysis as supported by the literature.

Introduction:

NMSCs or keratinocyte carcinomas are predominantly BCCs and SCCs. There are numerous treatment options available to treat these cutaneous malignancies including electrodessication and curettage, topical immunomodulators or chemotherapeutic agents, photodynamic therapy, surgical excision with and without frozen section diagnosis, MMS, RT as primary or adjuvant therapy and multi-modality therapy for advanced or systemic disease. Untreated or recurrent cutaneous malignancies can result in significant morbidity and mortality upon further progression of disease. The goal of therapy is to minimize recurrence(s) while taking into consideration associated comorbidities, size and location of the lesion(s), histology of the lesion(s) and ultimate outcome whether it be surgical or nonsurgical treatment. 4-9

Evidence-Based Guidelines for Standard of Care