The Treatment of Non-Melanoma Skin Cancer with Image-Guided Superficial Radiation Therapy: An Analysis of 2917 Invasive and In Situ Keratinocytic Carcinoma Lesions

Abstract

Introduction An image-guided form of superficial ionizing radiation therapy (IGSRT) is becoming a commonly used alternative to surgery for non-melanoma skin cancer (NMSC). However, there is little literature evidence evaluating the efficacy and safety of this approach. This study evaluates the efficacy and safety of IGSRT in treating a large number of patients with NMSC. Methods The medical records of 1632 stage 0–II patients with 2917 invasive and in situ NMSC lesions treated from years 2017 to 2020 were reviewed. No patients had clinical evidence of regional lymph node or distant disease at presentation. Results Treatment, guided by pre-treatment ultrasound imaging to adjust radiation energy and dose, combined with a fractionation treatment schedule of 20 or more treatment fractions, was safe and well tolerated. Of 2917 NMSC lesions treated, local tumor control was achieved in 2897 lesions, representing a 99.3% rate of control. Conclusion IGSRT should be considered as a first-line option for treating NMSC tumors in suitable early stage patients. Cure rates observed in this initial period of follow-up are similar, and potentially superior with further follow-up, to traditional superficial radiation therapy (SRT) and surgical options. Supplementary Information The online version contains supplementary material available at 10.1007/s40487-021-00138-4.

High resolution dermal ultrasound (US) combined with superficial radiation therapy (SRT) versus non-image guided SRT or external beam radiotherapy (XRT) in early-stage epithelial cancer: a comparison of studies

“…B Minor differences may be present in the raw numbers of each histologic subtype [BCC, SCC, SCCIS] used in the original analysis by Yu et al and the raw numbers used in this analysis. 8 These differences can be attributed to variations in data filtering.…”

“…Absolute and relative contraindications to IGSRT include lesion invasion to underlying bone or muscle, thickness > 6mm, previous radiation to the same lesion site, ataxia telangiectasia, active connective tissue disease, lupus or rheumatologic disease, concomitant management with radiation sensitizing chemotherapy agent, T4 stage, and node positive status. 8 IGSRT could be considered the preferred standard non-surgical radiotherapeutic treatment modality for appropriate patients with early-stage NMSC (BCC, SCC, SCCIS) with comparable LC to MMS without the drawbacks of surgery. At the minimum, patients should be presented with the option to have their NMSC treated with IGSRT.…”

“…This has led to the development of image-guided superficial radiation therapy (IGSRT) commercial units in 2013 that allow for lesion visualization prior to, during, and after treatment. 8 A recently published study by Yu et al . using IGSRT to treat 2917 early-stage keratinocytic cancers yielded a high local control (LC) rate of 99·3%.…”

“…This has led to the development of image-guided superficial radiation therapy (IGSRT) commercial units in 2013 that allow for lesion visualization prior to, during, and after treatment. 8 A recently published study by Yu et al using IGSRT to treat 2917 early-stage keratinocytic cancers yielded a high local control (LC) rate of 99•3%. 8 An updated abstract that added 93 patients and 133 lesions for a total of 1725 patients with 3050 early-stage keratinocytic lesions showed a continued high local control (LC) of 99•2%.…”

Analysis of Image-Guided Superficial Radiation Therapy (IGSRT) on the Treatment of Early Stage Non-Melanoma Skin Cancer (NMSC) in the Outpatient Dermatology Setting

“…The tumor depth is used to correlate with the percentage depth dose (PDD), which determines the selection of energy (50, 70, or 100 kV) delivered, and adjustments can be made during the treatment. The most recent and largest modern study (2917 cases of early-stage SCCIS, T1 and T2 NMSC) conducted by Yu and colleagues in 2021 demonstrated that IGSRT had an absolute local control rate of 99.3%, which was stably unchanged at the follow-up intervals of greater than one year to a max of 4 years [24].…”