A Systematic Review on the Impact of Hypofractionated and Stereotactic Radiotherapy on Immune Cell Subpopulations in Cancer Patients

Abstract

We investigated how hypofractionated radiotherapy (HFRT) and stereotactic body radiotherapy (SBRT) may impact immune cells in different type of tumors. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The PubMed, Embase and Cochrane databases were searched. Overall, 11 studies met the inclusion criteria and were eligible for the present analysis. Both HFRT and SBRT have different impact on lymphocyte subpopulations, confirming their immunomodulatory effect which may have a crucial role in future combined treatment with new emergent therapies such as immunotherapy. Further studies are needed to shed more light on this emerging topic to ultimately improve patient care, treatment and clinical benefits for cancer patients.

Cytokine Release Syndrome in a Patient With Metastatic Triple-Negative Breast Cancer Treated With Hypofractionated Radiation Therapy, Who Had Previously Undergone Immunotherapy: A Case Report

“…Preliminary studies have demonstrated a significant modification of both the tumor immune environment and the peripheral immune cell landscape after hypofractionated and stereotactic regimens. 16 This is exemplified by a recent randomized phase 2 trial, where the combination of stereotactic ablative RT with immunotherapy showed a notable improvement in event-free survival in early-stage non-small-cell lung cancer. 17 Exploring the combination of hypofractionated or stereotactic ablative RT with immunotherapy holds promise, crucial for revealing RT's immunomodulatory impacts and enhancing our grasp of its therapeutic possibilities.…”

Impact of Radiotherapy on Circulating Regulatory T-Cell Levels in Melanoma Patients

“…Previous research has shown that radiation-induced immune modulation is governed by various factors, such as dose, fractionation, sequencing with other therapies, and intrinsic radiosensitivity [30,31]. Hypofractionated high-dose regimens appear to elicit abscopal responses more readily than conventional fractionation [32]. This difference may be related to differences in lymphocyte apoptosis induction between regimens.…”

Financial Toxicity in Radiation Oncology

“…Fewer appointments and/or shorter treatment courses provide numerous opportunities for patients to decrease spending and time away from work [13]. Hypofractionated regimens are being increasingly used both for curative as well as palliative treatments in brain malignancies, head and neck cancers, thoracic cancers, colorectal cancers, pancreatic cancers, gynecological cancers, skin cancers, and palliation, among others [14]. We discuss a few recent examples of the cost-effectiveness of hypofractionated short-course radiation.…”