Unconventional radiotherapy to enhance immunotherapy efficacy in bulky tumors: a case report

Immunotherapy. 2021 Dec;13(18):1457-1463. doi: 10.2217/imt-2020-0289. Epub 2021 Oct 19.


Determining the most appropriate management strategy for patients with large tumor masses is a very challenging issue. Unconventional radiotherapy modalities, such as spatially fractionated radiation therapy (SFRT), are associated with dramatic responses. Recent studies have suggested that systemic immune activation may be triggered by SFRT delivery to primary tumor lesion. This report describes the case of a patient treated with a novel form of immune-sparing partially ablative irradiation (ISPART) for a bulky peritoneal metastasis from renal cell cancer, refractory to anti-PD-1 therapy (nivolumab) as third-line therapy after sequential therapy with sunitinib and cabozantinib. The observed response suggests that there may be a synergistic effect between ISPART and immunotherapy. This case report supports the inclusion of ISPART in patients presenting with bulky lesions treated with checkpoint inhibitors .

Keywords: immunoradiotherapy; immunotherapy; magnetic resonance-guided radiation therapy; spatially fractionated radiation therapy; unconventional radiation therapy.

Plain language summary

Lay abstract Managing large tumor masses is a very challenging issue. In recent years, radiotherapy methods have been linked with good responses, which may be due to the activation of immune mechanisms. We describe the case of a patient with a large tumor mass from renal cell cancer. The patient had already been treated with anti-PD-1 therapy, after treatment with sunitinib and cabozantinib, along with radiotherapy. The results suggest that radiotherapy together with immunotherapy is very effective in enhancing immune response.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anilides / administration & dosage
  • Antineoplastic Combined Chemotherapy Protocols / administration & dosage*
  • Carcinoma, Renal Cell* / immunology
  • Carcinoma, Renal Cell* / pathology
  • Carcinoma, Renal Cell* / therapy
  • Dose Fractionation, Radiation*
  • Female
  • Humans
  • Immunotherapy*
  • Kidney Neoplasms* / immunology
  • Kidney Neoplasms* / pathology
  • Kidney Neoplasms* / therapy
  • Middle Aged
  • Neoplasm Metastasis
  • Nivolumab / administration & dosage
  • Peritoneal Neoplasms* / immunology
  • Peritoneal Neoplasms* / pathology
  • Peritoneal Neoplasms* / therapy
  • Pyridines / administration & dosage
  • Sunitinib / administration & dosage


  • Anilides
  • Pyridines
  • cabozantinib
  • Nivolumab
  • Sunitinib