We performed a retrospective chart review of 68 patients with 93 BCCs who had been treated with nonablative laser therapy as an alternative to surgery at the Mount Sinai Faculty Practice Associates between February 2011 and December 2018. Patients were followed throughout this period for assessment of clinical and subclinical recurrence. The Icahn School of Medicine at Mount Sinai Program for the Protection of Human Subjects provided institutional review board approval.
Inclusion criteria included the following: (1) BCC diagnosed by biopsy (see eTable 1 for subtypes) and (2) treated with a nonablative laser due to patient preference and eligibility by the principal investigator (PI). As a retrospective study, lesions were included irrespective of tumor subtype or size. Although the risk for perineural invasion (PNI) is extremely low with BCC (<0.2%), none of the cases demonstrated PNI on diagnostic biopsy and none exhibited clinical evidence of PNI, such as paresthesia, pain, facial paralysis, or diplopia.24
Eligibility determined by the PI included limited clinical ulceration or bleeding, or both, and a safe distance from the eye when wearing an external eye shield (ie, outside the orbital rim). Patients who had Mohs micrographic surgery (MMS) or excision (or both) with recurrence at the treatment site were included. Detailed and thorough clinical and dermoscopic skin examination was critical in early detection of these cancers, allowing for treatment of less advanced tumors. The PI’s diagnostic approach utilized the published diagnostic color wheel algorithm,25 which encompasses both clinical and dermoscopic colors and patterns for early diagnosis (ie, ulceration, pink-white to white shiny areas, absence of pigmented network, leaflike structures, large blue-gray ovoid nests or globular structures, spoke wheel structures, a crystalline pattern, a singular vascular pattern of arborizing vessels), combined with OCT or RCM, when necessary.26 All lesions were imaged with OCT prior to laser treatment to confirm residual tumor following biopsy.
Although postsurgical patients were included, lesions receiving concurrent or prior nonsurgical therapy, such as a topical immunomodulator or oral hedgehog inhibitor (eg, vismodegib), were excluded.
All patients received thorough information about the treatment, treatment alternatives, and potential adverse effects and complications. Lesions were selected based on clinical and dermoscopic findings and were biopsy confirmed. Clinical and dermoscopic photographs were taken at every visit. A camera was used for clinical photographs and a dermatoscope was attached for all contact polarized dermoscopic images. All lesions were imaged with OCT prior to laser therapy to delineate tumor margins and to confirm residual disease following biopsy to preclude biopsy-mediated regression.
Laser treatment consisted of a 595-nm PDL followed by fractional laser treatment with the 1927-nm setting. The range of PDL settings was similar to published studies of PDL for BCC (spot size, 7–10 mm; fluence, 6–15 J/cm2; pulse duration, 0.45–3 milliseconds).3-8 The fractional laser also was used at settings similar to earlier studies for actinic keratosis (fluence, 5–20 mJ; treatment density, 40%–70%).27 Laser treatment was performed by 1 of 5 medically trained providers who were fellows supervised by the PI.
All tumors received 1 to 7 treatments (average, 2.89) at 1- to 2-month intervals. Treatment end point (complete clearance) was judged on the absence of skin cancer clinically, dermoscopically on OCT, or histologically by biopsy, or a combination of these modalities. Recurrence was defined as a new histologically confirmed BCC occurring in an area that was previously documented as clear. Patients returned for follow-up 1 to 2 months after the final treatment to monitor tumor clearance and subsequently every 6 to 12 months for tumor recurrence. Posttreatment care included application of a thick emollient, such as a petrolatum-based product, until the area completely healed.
Clinical photographs, dermoscopic photographs, OCT scans, RCM scans, and biopsy reports were reviewed for each patient, as applicable. All patients were given an unidentifiable number; no protected health information was recorded. Data recorded for each patient included age, tumor subtype and location, tumor size, classification of the tumor as primary or a recurrence, number of treatments, treatment duration, lesion clearance, and length of follow-up.