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CASE REPORT article

Front. Oncol.
Sec. Cancer Immunity and Immunotherapy
Volume 15 - 2025 | doi: 10.3389/fonc.2025.1483117

Low Dose Radiation Reverses Pembrolizumab Resistance in Melanoma: Case Report

Provisionally accepted
Ka Hey Agnes Fong Ka Hey Agnes Fong 1Isaac Ho Isaac Ho 2Tsz Him So Tsz Him So 3*
  • 1 Princess Margaret Hospital, Kowloon, Hong Kong, SAR China
  • 2 Queen Mary Hospital, Hong Kong, Hong Kong, SAR China
  • 3 The University of Hong Kong, Pokfulam, Hong Kong, SAR China

The final, formatted version of the article will be published soon.

    Immunotherapy has been the mainstay of the initial systemic treatment for metastatic melanoma regardless of the tumour's genetic mutation status (Atkins et al., 2022). It is known to offer long-term overall and treatment-free survival benefits, also with generally tolerable side effect profiles. However, upon disease progression on first-and second-line immunotherapy, further systemic treatment options are limited especially for cases without actionable molecular alterations.With emerging evidence suggesting that radiotherapy can enhance the efficacy of immunotherapy via various mechanisms, together with its potential abscopal effect, the possibility of overcoming immunotherapy resistance with radiotherapy is theoretically sound. We report a case of metastatic melanoma which demonstrated reversal of immunotherapy resistance after addition of low-dose radiotherapy to progressive tumour. Complete metabolic remission is achieved with durable response observed.

    Keywords: Melanoma, Low dose radiation (LDR), Immunotherapy, Pembrolizumab, Radiation

    Received: 19 Aug 2024; Accepted: 13 Jan 2025.

    Copyright: © 2025 Fong, Ho and So. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Tsz Him So, The University of Hong Kong, Pokfulam, Hong Kong, SAR China

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