A comprehensive analysis of brachytherapy clinical trials over the past 15 years

Abstract

Purpose: Clinical trials (CTs) involving brachytherapy (BT) are crucial in establishing the role of BT in the evolving landscape of cancer treatment. An analysis of BT trials is warranted to understand the factors driving their success and the future direction of the field.

Methods and materials: We queried the clinicaltrials.gov website using the search terms: Radiation Therapy, Brachytherapy, and associated terms. This yielded 10,417 CTs between 2000 and 2015. Trials not using BT were excluded; yielding 319 CTs. Characteristics of individual CTs were obtained. Least squared linear regression, χ² analysis, and logistic regression were used to evaluate trial characteristics.

Results: The majority of the CTs were phase II (37%), involving interstitial BT (45%), and treating the prostate (36%). Nongovernmental institutions (NGIs) have funded the greatest number of CTs. New CTs involving radiotherapy of all types showed increase over time (p < 0.05), whereas no corresponding increase was seen in BT trials. New BT trials independently funded by industry have declined (p = 0.01). Collaboration between industry and NGIs was associated with greater likelihood of trial completion. Industry funding was associated with Phase IV trials, usage of surface BT, among others. NIH/government funding was associated with Phase I trials, intracavitary BT, trials focused on systemic therapy, among others.

Conclusions: Trials examining radiotherapy have increased, whereas trials incorporating BT have remained unchanged. Collaboration between industry and NGIs was associated with a greater likelihood for successful trial completion. The role of BT can be better realized with greater incorporation into CTs.

Keywords: Brachytherapy; Clinical trials.