numerical study of the effect of urine presence and convection on magnetic nanoparticle hyperthermia in the treatment of bladder cancer

Magnetic nanoparticle hyperthermia is a preclinical treatment for bladder cancer that employs ferromagnetic nanoparticles exposed to an external alternating magnetic field to elevate the temperature within the tumor. in this study, magnetic hyperthermia using fe3o4 nanoparticles was simulated for t1 non-muscle-invasive bladder cancer and t2 muscle-invasive bladder cancer, investigating the effect of presence of urine and its convection within the bladder in this treatment method. for this purpose, simulations for both stages of bladder cancer were conducted for three cases. first, the bladder without urine was modeled as a homogeneous solid muscle tissue. next, to investigate the effect of the absence of perfusion, the bladder containing urine was modeled, but the effect of convection was neglected. finally, the bladder containing urine was modeled, incorporating the effect of convection. the distribution of the volumetric heat generation rate due to induction heating, the volumetric power dissipation of the magnetic nanoparticles, and the temperature are presented for three simulation cases and two stages of bladder cancer. pennes and navier-stokes equations were used to obtain the temperature distribution in solid tissues and fluid, respectively. the equations were solved using the finite element method in two dimensions. the results demonstrate that in magnetic nanoparticle hyperthermia, convection within urine increases heat generation, reduces temperature, and creates a non-uniform temperature distribution in the tumor for both stages of bladder cancer. additionally, the more uniform temperature distribution in t1 compared to t2 suggests that this treatment is more effective for non-muscle-invasive bladder cancer than for muscle-invasive bladder cancer.