Radiotherapy for symptomatic knuckle pads/Garrod’s nodes associated with palmar fibromatosis/Dupuytren’s disease: Report of a case series

Summary: Knuckle pads, or Garrod’s nodes, have been associated with various conditions but are most often diagnosed in patients with palmar fibromatosis also called Dupuytren’s disease. The reported incidence in patients with palmar or plantar fibromatosis varies between 2.4% and nearly 50%. The diagnosis is typically made clinically, presenting as thickened subcutaneous tissue on the extensor side of the proximal interphalangeal (PIP) joint. The nodule is mobile over the joint and adheres to the skin with no sign of synovitis. All fingers can be involved, predominately the index finger, whereas the thumb is typically not affected. Symptoms can include pain, cosmetic concerns, limited range of motion, and restriction of daily activities, and often persist into adulthood. At present, no widely accepted treatment for knuckle pads has been established. While knuckle pads might have been included in previous radiotherapy (RT) series, no dedicated report on the outcome of RT for symptomatic knuckle pads is available to the best of our knowledge. Here we describe the outcomes of nine patients with knuckle pads at the PIP joint treated with RT at our institution over 12 years. After IRB approval, we identified eligible patients who had received RT for knuckle pads between 2012 and 2024, and then obtained their informed consent to be contacted regarding outcomes. Patients completed a questionnaire at time of consult and at periodic intervals following treatment completion. We then analyzed and reported on patient demographics, treatment plans, time since treatment, patient satisfaction, and knuckle pad response to RT. 9 Caucasian patients, ages 42-63 years old, including 7 females and 2 males, completed radiation to knuckle pads and completed the questionnaire at time of follow-up. One patient had received prior RT near the involved knuckle pad. 8 patients received simultaneous RT to the palms and/or soles. Time since treatment ranged from 3-12 years. Treatment included a split course prescription to 30 Gy in 10 daily fractions with a 6-8 week mid treatment break. Electron beams ranged from 6-12 MeV prescribed to the 90-100% isodose line using 1cm-1.5cm bolus. Regarding treatment response, 7 patients (77.8%) reported improved symptoms since RT, 1 (11.1%) reported stable (no progression) disease, and 1 (11.1%) reported worse/no improvement. Minimal acute and chronic toxicity was reported. Regarding patient satisfaction, 8 patients reported favorable outcomes. Our study details the treatment response of 9 patients with knuckle pads to RT. Patients tolerated treatment well, with the majority reporting symptomatic and physical improvement, as well as favorable satisfaction with outcomes. This study demonstrates the safety, tolerability, and efficacy of RT for treatment of knuckle pads, with a dose of 30 Gy providing durable disease control, and suggests it is a safe and effective treatment option for knuckle pads. Amanda Stark (she/her/hers), Dr (Presenting Author) - Massey Comprehensive Cancer Center at VCU Health System; Elisabeth Weiss, MD (Co-Author) - Massey Comprehensive Cancer Center at VCU