Tehran University Medical Journal

Today, nanoscience has grown and developed in various medical and therapeutic areas, including cancer treatment. On the other hand, cancer and its types have been rumored and inclusive and many people suffer from this fatal and deadly disease. Currently, existing therapeutic method, including chemotherapy, radiotherapy, and etc., along with the therapeutic effect, cause complications that are unpleasant for patients. Hence, scientists and researchers are looking to develop and improve treatment options and methods to deal with this serious disease. Today, nanoscience and nanotechnology have become widespread, and its various fields, including nanoparticles, are widely used for a variety of applications, especially for delivery of drugs and diagnostic items and imaging cases. Nanotechnology-based release systems have a significant impact on the release of cancer drugs. Advances in bio-materials and bio-engineering are contributing to new approaches to nanoparticles that may create a new way for the improvement of cancer patients. Nano-technology in the drug release system has had a great impact on the selection of cancer cells, the release of a targeted drug, and overcoming the limitations of conventional chemotherapy. At the present many drug delivery systems are now made of nanoparticles, and various substances have been used as drug-stimulating agents or as a reinforcing agent to improve the efficacy of the treatment and durability and stability and also the safety of anticancer drugs. The materials used to release cancer drugs are divided into various categories such as polymer, magnetic, biomolecules. In the meantime, polymer nanoparticles have been organized in the carriers of anti-cancer nanoparticles due to the process of easy production, biocompatibility, and biodegradability. Although the loading of hydrophilic compounds is still confronted with limitations, due to the diversity of nanoparticle structures, it is possible to encapsulate various molecules. Also, surface changes and modification such as binding to antibodies and target ligands can also be applied to these materials, to act as target drug delivery to increase the effectiveness of treatment process. In this article, we will have an overview of cancer disease and cancer drugs and also nanoparticles and their contribution to cancer treatment.

Background: Recent advances in modern radiotherapy techniques such as Intensity-Modulated Radiation Therapy (IMRT) and Stereotactic Radiosurgery (SRS) have significantly increased the need for accurate and reliable dosimetry in radiation therapy. Accurate dose delivery is particularly critical in small electron fields, which are increasingly used in targeted treatments. However, these fields pose unique challenges due to factors such as electron disequilibrium, increased lateral scatter, and steep dose gradients. These physical characteristics can introduce significant uncertainties in dose distribution, thereby reducing the effectiveness and safety of the treatment if not properly accounted for. Traditional dosimeters often struggle to maintain accuracy under such conditions. The aim of this study was to evaluate the performance of MAGIC polymer gel as a three-dimensional (3D) dosimeter in small electron fields and to compare its dosimetric characteristics with standard dosimeters including diode, semiflex, and pinpoint. Methods: This experimental and applied study was conducted at the Radiotherapy Department of Imam Reza Hospital, Kermanshah, Iran, over a one-year period from December 2022 to December 2023. Five electron field sizes (2×2, 2.5×2.5, 3×3, 4×4, and 5×5 cm²) were generated using an Elekta linear accelerator at two electron beam energies of 6 and 9 MeV. MAGIC polymer gel phantoms were irradiated accordingly and scanned with a 1.5 Tesla MRI system to obtain three-dimensional dose distributions. These were compared to measurements obtained from diode, semiflex, and pinpoint dosimeters. Results: The depth dose curves of MAGIC gel exhibited greater agreement with diode measurements compared to those from semiflex and pinpoint detectors. As field size decreased and beam energy increased, discrepancies in absorbed dose readings between different dosimeters became more apparent. These results underscore the importance of selecting appropriate dosimetric tools for accurate dose evaluation in small-field electron beams. Conclusion: MAGIC polymer gel demonstrated strong potential as a reliable 3D dosimeter for small electron field dosimetry, showing the highest compatibility with the diode dosimeter.