Radiotherapy for Keloids

The purpose of this pilot study is to evaluate the safety and efficacy of radiation therapy (RT) in the treatment of unresected keloids.

This will be a single-institution pilot study to evaluate the safety and efficacy of radiation therapy (RT) for the treatment of unresected keloids. The primary endpoint will be toxicity within 10 weeks of follow-up. Secondary endpoints will include cessation of growth or shrinkage of keloids, symptomatic response, and impact on quality of life. Primary Objective -evaluate feasibility and safety of radiation therapy only for the treatment of unresected keloids. Secondary Objectives: To evaluate toxicity of RT for the treatment of unresected keloids. To evaluate response of keloids, either stability or decrease in size, after primary RT. To evaluate symptomatic response of unresected keloids to primary RT. To assess the effect on quality of life of primary RT for unresected keloids After review of the literature on the use of RT for the treatment of keloids, both resected and unresected, as well as input of expert opinion and clinical experience by the study's radiation oncologists, the RT prescription dose for this study was selected to be 15 Gy, which will be divided into 5 Gy fractions delivered daily over on 3 consecutive days. Patients will receive RT using external beam radiotherapy (EBRT), delivered via either electrons or megavoltage photons, or brachytherapy; RT modality will be based on the judgment of the treating radiation oncologist. We estimate we will be able to recruit 15- 20 patients in 6-12 months, thus we are aiming for a sample size of 15 patients. In successive intervals of enrollment and treatment of 5 patients (i.e. after 5, 10, and 15 patients have been enrolled), the study team will meet and perform interim analysis to evaluate the safety and efficacy of treatment. Investigators will discuss rates of toxicity and symptom management observed up to that point and determine if the study dose or protocol needs to be altered. Patients will be evaluated frequently (see study calendar) for treatment-related toxicities using CTCAE v5.0 up to 1 year after completion of RT. Any adverse event will be considered by the study investigators to evaluate the safety of the protocol and to determine whether changes to the dosing regimen are required.

Patients will be seen by a treating radiation oncologist and treatment with the assigned dose schedule will be planned using either EBRT with electrons or high dose-rate radiotherapy (HDR) brachytherapy as deemed appropriate by the treating radiation oncologist. The treatment dose of 15 Gy in 3 fractions will be prescribed to the 90% isodose line.

Incidence of adverse events as assessed by skin and subcutaneous tissue disorders grade 2 or higher using CTCAE criteria

incidence of grade 2 or higher skin AEs using CTCAE criteria at each study visit (before RT, at week 2, week 6, week 10, month 6, 9 and 12)

Inclusion Criteria: Clinically diagnosed keloid -Surgical excision of keloid is either contraindicated or patient has declined treatment with surgical excision. Note: patients with keloids that recurred after previous resection are eligible, as long as the current keloid is either unresectable or patient has decline resection. Age ≥18 Study specific informed consent provided Exclusion Criteria: Prior RT to the area of interest that would result in overlap of radiation therapy fields Females of child bearing age without a negative serum pregnancy test prior to initiation of RT or unwilling to use contraception prior to and during the radiation course Keloids in areas where radiation therapy introduces unacceptable high risk of toxicity as determined by the treating radiation oncologist Uncontrolled intercurrent illness (e.g. symptomatic congestive heart failure, uncontrolled cardiac arrhythmia, or psychiatric situation) that would limit compliance with study requirements as judged by the treatment physicians