Perpetual role of brachytherapy in organ-sparing treatment for bladder cancer: a historical review

Brachytherapy-based radiotherapy has been applied for decades in the curative treatment for solitary, ≤ 5 cm bladder tumors. This review provides a historical perspective of this organ sparing approach. A systematic search of the published literature between 1900 and 2019 was performed on the subject of bladder brachytherapy using PubMed, with digitally retrievable articles being supplemented with articles from the personal collection of the authors. The articles were divided into consecutive time periods, each reflecting the impact of authors on the development of brachytherapy treatment: the time of pioneers, early innovators, modifiers, and recent innovators. Three case-controlled studies comparing brachytherapy-based organ-sparing treatment with cystectomy, demonstrated similarity between the two approaches in terms of disease-free and overall survival, whereas brachytherapy-based approach offered the advantage of at least 80% chance of bladder preservation. The overview was organized in a chronological order, starting from the evolution of brachytherapy from radium, followed by remote afterloading and dose-rate adjustments, and closing with modern era of high-dose-rate and image-guided brachytherapy. Importantly, we demonstrated how essential and beneficial for the patients is a close collaboration between radiation oncologists and urologists, and how adopting a modern surgical development, i.e. the laparoscopic implantation technique, which later became robot-assisted, contributed to the success of this multidisciplinary brachytherapy treatment. We concluded that this highly effective brachytherapy method with very limited toxicity deserves more worldwide popularity.