Office-based thermal-treatments for unmet urological diseases in women and men (Bladder  cancer Prostatitis)

Hot solutions for Bladder cancer & Prostatitis

 

  Technology:

 Bladder wall thermo-chemotherapy (BWT) provides chemotherapy instillation at a uniform and precise 44OC-44.5OC over the entire bladder lumen. To secure drug stability and achieve an exact and uniform temperature, BWT uses a carefully heated mitomycin C (MMC) solution at a pre-determined hyperthermia temperature which circulates through the bladder in a high flow where the whole bladder content is replaced 4-5 times per minute. The uniqueness of BWT is that the heat content of the circulating solution exceeds what is required to transfer to the thermally conductive bladder wall.

The use of conductive-heat at constant temperature assures no burn what-so-ever (because the bladder lumen temperature is less than 45OC at any time). From there, bio-physics allows moderate temperature gradient that enables 42OC 4mm deep in the bladder wall. These simple principles enable precise and uniform temperature regardless the fact that different patients have different blood perfusion and different tissue properties. Moreover, this naturally controlled mechanism compensates easily for dynamic changes that occur over time such as vasodilation, with no need for irrelevant adjustments.



                         Circulation of drug-solution in the bladder

  

Combination of heat and drug has synergy between two phenomena:

a) Heat selectively damages the cancer tissue
    (neoplastic tissue) and, independently,

b) Heat increases tissue drug uptake by 3 mechanisms:
     - Heat increases blood flow   

        (more drug available to the tissue)

      - Heat increases cell membrane  

        permeability to the drug

      - Heat accelerates drug metabolism 

        (with every one centigrade over 37 centigrade

        metabolism increased about 50%) 

 

BWT vs. Other technologies heating:

Contrary to the simplicity of the conductive-heat mechanism, the "sophisticated” heating is notoriously known to be non-homogeneous with "hot spots”– burns (in the bladder, at the posterior bladder wall), and "cold spots” - places of ineffective heating (in the bladder, at the dome and near the trigone). The claim to fame of the "other" thermo-chemotherapy for NMIBC is the use of cooled drug that is not heated while the energy is used to heat only the bladder wall. This claim is misleading as the precooled drug solution is well heated in two places during circulation: in the catheter were the drug flows very slowly in the same lumen where the very hot radiating antenna resides and in the bladder where the drug stays for a long time close to the catheter with the radiating antenna. Due to the slow flow in the microwave system, bladder content replaced every 12-20 minutes – about 60 times slower than in BWT. In the microwave system, the bladder wall tissue temperature is measured on the surface of bladder lumen, at the drug-tissue interface. According to physics, with that slow flow, it is impossible that at this interface the drug is "cold” and the tissue is "hot” as these two temperatures should be very close to each other.In a standard microwave procedure this temperature does not exceed 42oC.

 

Considerations in bladder thermo-chemotherapy:

Treatment temperature

Efficacy of bladder thermo-chemotherapy in NMIBC is temperature dependent as proved by a microwave system (Synergo®, targeted treatment temperature 42oC), where treatments performed above 42oC compared to those performed below 42oC showed 44% increase in efficacy. Because "heat is heat", efficacy is independent of the heat source as long as the heat is uniform and does not affect the drug. Compared to microwave, BWT is performed at a higher uniform temperature (range 44oC-44.5oC).

 

Temperatures in the system:

Large surface area of the unique conical heat exchanger and the high flow circulation allow a small temperature delta of only 2OC above the treatment temperature in the bladder which means that the drug is exposed to very moderate temperature to maintain its potency. Due to the high flow, the temperature gradient between entry and exit of the catheter is only 0.8OC to 1.2OC. Therefore, the uniform temperature inside the bladder is 0.4OC to 0.6OC below the temperature measured at the entry of the catheter and measuring the temperature inside the bladder is not required.

From bladder surface down to the bladder wall, bio-physics allows moderate temperature gradient to about 42OC at 4mm depth (about 0.6OC per 1mm).


 

 

 


®   Drug exposure to temperature

The indifference to the heat source is valid as long as the drug is not exposed to a too high temperature which damages it. In BWT, due to the high-flow circulation of the carefully heated drug solution, only a small temperature gradient between heat-source and treatment-site is required to induce an effective heating of the bladder wall. In the microwave system, the drug is exposed to a very high temperature in the catheter and high temperature in the bladder. 

®   Drug concentration

Efficacy of thermo-chemotherapy in NMIBC is also drug-concentration dependent and it is agreed that higher drug concentration results in better efficacy. In microwave procedure (which comprises 2 sub-sessions lasting 30 minutes each), the full dose 40mg or 80mg MMC is divided into two half doses of 20mg or 40mg MMC and each half dissolved in 50ml water. In contrast, BWT is a 50 minute continuous session where the full dose 40mg or 80mg MMC dissolved in 50ml water.

®   Adverse events and patients’ tolerance

BWT provides better patients’ tolerance and less adverse events than microwave due to the absence of "hot” spots and to the non-traumatic insertion of the BWT flexible catheter (which does not include any rigid part).

®   Ease of operation

Compared to microwave, BWT is easier to perform as no adjustments required during the procedure. 

®   Economics

BWT is much more economic than microwave where the BWT console costs only a fraction of the microwave console and the disposable set is 50%-70% less than the cost of the microwave one.  

 

 Office-based procedures with best patient's tolerance:

· No pain; performed with topical anesthesia only.

· No post-procedure Catheter.

· No rectal, bladder or tissue temperature probes.

· Patient returns back to normal activities the same day.

 

 

 

 

 

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