Systematic review of brachytherapy for symptom palliation

Abstract

Purpose: Brachytherapy is most often applied in the curative or salvage setting, but many forms of brachytherapy can be helpful for symptom palliation. Declining utilization is seen, for multiple reasons, such as lack of awareness, insufficient expertise, or poor access to equipment. High level evidence for many types of palliative brachytherapy has been lacking. The objective of the current study was to review the evidence for utilization and efficacy of brachytherapy to palliate symptoms from cancer.

Materials and methods: We performed a systematic search in EMBASE and MEDLINE for English-language articles published from January 1980 to May 2022 that described brachytherapy used for a palliative indication in adults with a diagnosis of cancer (any subtype) and at least one symptom related outcome. Individual case reports and conference abstracts were excluded. All publications were independently screened by two investigators for eligibility.

Results: The initial search identified 3637 abstracts of which 129 were selected for in-depth review. The number of studies (total number of patients) included in the final analysis varied widely by tumor site with the majority (68.2%) involving either lung or esophageal cancer. Despite a limited number of prospective trials that assessed the efficacy of brachytherapy for symptom management, there was a positive effect on palliation of symptoms across all tumor types. There was no clear trend in the number of publications over time. The most commonly cited symptom indications for palliation by brachytherapy were dysphagia, dyspnea, pain and bleeding.

Conclusions: Brachytherapy can provide palliation for patients with advanced cancer, across different tumor sites and clinical scenarios. However, high level evidence in the literature to support palliative applications of brachytherapy is lacking or limited for many tumor sites. There appears to be a strong publication bias towards positive studies in favor of brachytherapy. Beyond anecdotal reports and individual practices, outcomes research can further our understanding of the role of brachytherapy in palliating advanced cancers of all types, and should be encouraged.

Keywords: Brachytherapy; Cancer; Palliative; Symptom control; Systematic review.