Brachytherapy in the treatment of invasive bladder cancer

Abstract

Organ preservation has been in the forefront of modern cancer treatment for the last few decades. Conservative treatment is now standard of care for numerous malignancies including breast cancer, laryngeal cancer, anal cancer, and soft-tissue sarcomas of the extremities. For patients with muscle-invasive bladder cancer, radical cystectomy with a pelvic lymph node dissection is still considered the standard treatment. Certainly since orthotopic bladder substitution has become available, many urologists prefer early definitive therapy with continent urinary diversion. Lately also for the bladder, organ-preserving strategies have gained renewed interest. Bladder preservation to the patient means less surgery, no need for a urinary diversion, and the possibility of a normal sexual life. Modern sophisticated techniques for urinary diversion have not altered the fact that cystectomy is still associated with physical and psychological limitations. 1 The discussion of bladder-sparing strategies has mainly focused on combinations of cisplatin-containing chemotherapy and external beam radiotherapy (EBRT) after transurethral resection (TUR) of the bladder tumor. 2-5 . In the discussion, the option of treatment with brachytherapy after TUR and EBRT (further addressed as brachytherapy) seems to be largely overlooked. All reports addressing this approach consistently mention high cure rates (70 to 90%) with excellent maintenance of bladder function. 6-11 Regardless of this favorable outcome, brachytherapy for bladder cancer remains a seldom performed procedure, only performed in a few specialized centers, mainly in France and the Netherlands. Brachytherapy for bladder cancer was developed in the first half of the 20th century and existed as the permanent implantation of radon seeds or the temporary implant of radium/cobalt needles or iridium wires. 12-14 Although effective, this form of treatment resulted in radiation exposure to the medical and nursing staff. Patients had to be treated for several days in shielded rooms often far away from the wards with experienced staff. Moreover the implantation of radioactive needles caused urinary leakage and wound infections in many patients, resulting in a mean hospitalization of more than a month. 15 Therefore it is not surprising that the treatment of bladder cancer with brachytherapy became increasingly unpopular. However, since then substantial progress has been made. In the 1980s, after-loading techniques were introduced, which eliminated the radiation exposure to the staff and significantly reduced the complication rate. 7,8 In the 1990s, pulsed dose rate (PDR) and high-dose rate brachytherapy(HDR)machineswithasingleiridiumsourcebecame available. The introduction of these techniques in bladder cancer will reduce the treatment time and thus be a major step forward in treatment logistics. With the fractionated brachytherapy machines, 3D CT scan based planning software became available, allowing dose distribution optimization and integration of brachytherapy with external beam radiotherapy (EBRT) planning. With these improvements, brachytherapy for bladder cancer deserves a second chance.