Research Research themes Urological cancers Radiofrequency-induced chemohyperthermia for non-muscle-invasive bladder cancer

Non-muscle-invasive bladder cancer (NMIBC) is a very common disease with a high incidence and, due to relatively low mortality rates and high recurrence rates, also with a high prevalence. Unfortunately, there is a risk of progression to muscle-invasive disease, which results in a mortality rate of about 30% in 5 years. As a result, NMIBC patients undergo regular follow-up cystoscopies, which are bothersome, costly, and invasive. Therefore, ways to improve the NMIBC disease management are being investigated.
Typically, intravesical instillations with chemotherapy or Bacillus Calmette-Guérin (BCG) immunotherapy are given to prevent recurrence and progression after trans-urethral resection of the bladder tumor (TURBT). However, efficacy can still be improved. In 2001, the Urology department of the Radboudumc started a research program on a new device-assisted approach to treat NMIBC: radiofrequency-induced chemohyperthermia (RF-CHT), also known as Synergo® or radiofrequency-induced thermal effect (RITE). This technique combines conventional chemotherapy with intravesical heating of the bladder wall. Since 2001, multiple PhD candidates have been assigned to evaluate this technique, showing that (i) the RF-CHT concept works, both in vitro and in vivo (Int J Hyperthermia 2016), (ii) why it works (Int J Hyperthermia 2017), and (iii) how well, and in which patient groups it works best (Eur Urol 2016). To date, the theme has moved RF-CHT further into clinical practice, in which RF-CHT is now being used in several international centers for NMIBC patients who are at the highest risk of disease recurrence and progression. As one of the potential alternative options to BCG – which may have severe systemic side-effects and has a restricted availability – and offering a chance on bladder preservation, RF-CHT has been incorporated in the NMIBC guideline of the European Association of Urology (Eur Urol 2017). Our research on this technique paved the way for device-assisted and combined therapies in NMIBC. Further evidence of its efficacy is awaited and needed to implement this technique more widespread.