Simulation of dose enhancement in radiotherapy caused by cisplatin

Abstract

This research considers potential dose increase in target due to cisplatin (Pt) concentration and radiation type. Cisplatin concentrations from 0.003 to 120 mM were used. Monte-Carlo simulation of Linear accelerator (Elekta Synergy) and X-ray tube (Xstrahl300) was carried out using Geant4 and PClab. As the first step of this research, we performed simulation of energy spectrum from radiotherapy units (spectrum model). The next step was the modeling of linear accelerator head and X-ray tube, and the distribution of dose in the water phantom (PDD model). At the second stage, dose changes were investigated in the presence of cisplatin in the target (CIS model). The simulation results showed that the dose escalation can be caused by photon-capture therapy (PCT). There is a dose enhancement in the volume where cisplatin is accumulated. Then higher is concentration, then higher is the effect. However, the photon energy increase from 60 to 250 kV and increase of depth of target reduces the effect of PCT due the decrease of the photoelectric effect cross-section. Should be noticed, that the orthovoltage X-rays energy, listed in the table with results shows higher dose enhancement, than the megavoltage photon beam generated from linear acceleration sources. In addition, that the dose enhancement factors (DEF) are higher in linac without flattening filter, than in linac with flattening filter.

Natural Baicalein-Rich Fraction as Radiosensitizer in Combination with Bismuth Oxide Nanoparticles and Cisplatin for Clinical Radiotherapy

“…53 Meanwhile, a Monte Carlo analysis on the water with 3% Cis for brachytherapy yielded a DEF of 1.07, and a Geant4 simulation with 12 mM of Cis for 6 MV energy yielded a DEF of 1.0047 to 1.0141. 109,110 The current study's theoretical DEF for the individual BiONPs and Cis differed from the studies described above. However, it could be considered consistent because the difference was less than 10%.…”

“… 53 The variance in DEF might be attributed to differences in component concentration and target location depth. 24 , 110 …”

“…53 The variance in DEF might be attributed to differences in component concentration and target location depth. 24,110 Meanwhile, when the BCB combination was present during brachytherapy, the experimental SER in NIH/3T3 normal cells was greater than the theoretical DEF, demonstrating that radiosensitization's physical, chemical, and biological routes might influence the healthy tissues surrounding the cancer sites. Nonetheless, these toxicity effects may be as minimal as the side effects of concurrent CRT in clinical research.…”

Accessing radiation damage to biomolecules on the nanoscale by particle-scattering simulations

“…Due to their action on the molecular scale, less MCS based studies are present in the literature with respect to cisplatin. Hereby the study by López-Laurrabaquio et al [262] used TOPAS-nBio to analyse ROS yields from secondary and Auger electrons scattering with cisplatin, while Baulin et al [263] quantified DEF from cisplatin interaction under x-ray irradiation. Furthermore, for appropriate MCS based studies of halogenated nucleotides future extensions of the simulation toolkits would need to incorporate related scattering cross sections and chemical reaction pathways for the involved molecular groups.…”