BWT - UniThermia

BWT treats non-muscle invasive bladder cancer (NMIBC).

BWT provides bladder wall thermo-chemotherapy with uniform hyperthermia all over the bladder by high flow of a heated Mitomycin-C solution.

BWT is based on conductive-heat which is better controlled in the bladder than microwave. In BWT, heat administered  precisely and uniformly all over the bladder without burns ("hot spots”) or ineffective low heating ("cold spots”).

Bladder chemotherapy instillation (usually mitomycin C – MMC) combined with hyperthermia (temperature range 40^ºC-45^ºC) called "bladder thermo-chemotherapy” and its efficacy is due to the synergy between two independent phenomena:

 -  Hyperthermia enhances drug uptake by cells and, independently,
 -  Hyperthermia selectively damages cancer cells and not the healthy tissue.

Efficacy of thermo-chemotherapy is temperature dependent
Efficacy of bladder thermo-chemotherapy instillations in NMIBC is temperature dependent as proved in a very large cohort of patients treated with 42^ºC targeted temperature with a microwave system.
This large group of patients was divided retrospectively to two groups:
- Patients that their treatments performed above 42^ºC
- Patients that their treatments performed below 42^ºC

Comparison of the resulted efficacy by the two ranges of temperatures showed 44% increase in efficacy in the group treated above 42^ºC vs. the group treated below 42^ºC. 
A closer analysis of the treatment efficacy in these patients showed that efficacy is improving with higher temperatures along the whole range of hyperthermia.

Bladder Wall Thermo-chemotherapy (BWT)
BWT provides chemotherapy instillation at a uniform and precise 44.5^ºC over the entire bladder lumen. Yet, with no burns what-so-ever. 
To secure drug stability and achieve an exact and uniform temperature, BWT uses a carefully heated (to an exact temperature) mitomycin C (MMC) solution which circulates through the bladder at a high flow and the whole bladder content is replaced 5 times per minute. 

Sound principles
BWT is unique due to the fact that the heat content of the circulating drug solution exceeds what is required to transfer to the thermally conductive bladder wall. Plenty of heat at a constant non-ablative temperature assures best efficacy with
no burn what-so-ever because the bladder lumen temperature is less than 45^ºC at any time.
These simple principles enable precise and uniform highest hyperthermia over the entire bladder lumen regardless of the fact that different patients have different blood perfusion and different tissue properties. Moreover, this simple controlled mechanism compensates easily for dynamic changes that occur over time (such as vasodilation) with no need for manual or software adjustments. 
This sophisticated simplicity is a key factor for BWT inherent best efficacy, best economics and for being the best user-friendly thermo-chemotherapy.

BWT (Bladder cancer) for NMIBC performed in two protocols

• Prophylaxis protocol: a 50 minutes procedure with uniform 44°C on bladder wall, in which 40mg Mitomycin-C dissolved in 50ml distilled water.
  6 weekly induction instillations followed by 6 monthly maintenance instillations.
• Ablation protocol: a 50 minutes procedure with uniform 44°C on bladder wall, in which 80mg Mitomycin-C dissolved in 50ml distilled water.
  6 weekly induction instillations followed by 10 monthly maintenance instillations.
  

• The better controlled conductive heat leads to better drug stability.
• The high rate circulation in the bladder continuously brings "fresh" heated drug in contact with all bladder wall.
• Uniform and precise bladder wall temperature maintained all over the bladder while there are:
• No "hot spots" (burns in posterior bladder wall), and
• No "cold spots" (ineffective low heating near the bladder dome or trigone).
The uniform and precise temperature enables increase of the targeted temperature to 44°C without adverse events.
• The absence of burns leads to increased patient tolerability to the treatment.
• Non-traumatic insertion of the 16Fr flexible catheter which has no rigid parts.