Browsing by Author "K. Mondal"

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Enhancing Fricke Xylenol Gel Dosimeter’s Response to Radiation with Optimized Preparation Methods
(Mashhad University of Medical Sciences, 2025) Shajid Syed Mohamed; Abhijit Mandal; K. Mondal; Gogul Priean V; Bratindranath Mukherjee; Praveen Chandra Pandey; Himanshu Mishra; Ritusha Mishra; Ganeshkumar Patel; Ankur Mourya; Lalit Mohan Mohan Aggarwal; Sunil Choudhary
Introduction: The fundamental principle of the Fricke gel dosimeter involves the oxidation of ferric ions upon exposure to radiation. However, a significant limitation of this dosimeter is the post-irradiation diffusion of ferric ions, which can result in the degradation of spatial dose information. Material and Methods: Gels were prepared using 300 bloom gelatin, deionized water, sulfuric acid, ferrous ammonium sulfate, and xylenol orange dye (Sigma-Aldrich). The solution was then poured into 10 ml plastic cuvettes. The gel samples were refrigerated at various temperatures for 1 to 10 days and irradiated within a water bath environment utilizing a telecobalt unit (Phoenix, Theratronics) employing parallel opposed beams. Spectrophotometric analysis at a wavelength of 585 nm was used to measured optical density changes with dose. This procedure was repeated across gel formulations prepared under differing pH conditions. Results: The gel’s optimum pH value, which was stored for 10 days at 5° C, showed a linear response up to 10 Gy, although the storage time was longer than that of the gels with low (0.3) and high pH (1.3). The auto oxidation rate was determined and found to be less for non-irradiated gel batches stored at 5° C in relation to the gel samples at room temperature and freezing temperature. Conclusion: The dose response of the dosimeter is highly dependent on its pH, composition, alkaline residuals, and pre-irradiation storing conditions. We observed the optimum pH is 1, at which the dosimeter shows a maximum response. Storing gel samples at 5°C notably reduces the Fe2+ to Fe3+ auto-oxidation rate. © (2025), (Mashhad University of Medical Sciences). All rights reserved.
Plan quality score to evaluate the dwell time deviation restricted inverse planning by simulated annealing and graphically optimized treatment plans for template based interstitial brachytherapy; [Score de qualité du plan pour évaluer l’écart de temps d'arrêt de la source en planification inverse restreinte par recuit simulé et plans de traitement optimisés graphiquement pour la curiethérapie interstitielle basée sur un modèle]
(Elsevier Masson s.r.l., 2023) K. Mondal; Muskaan; A. Mourya; S. Choudhary; A. Mandal; A. Singh; L.M. Aggarwal
Purpose: To evaluate the impact of dwell time deviation constraint (DTDC) on the quality of IPSA-optimized treatment plans in comparison with graphical plans using plan quality scores (PQS). Material and methods: Seventy optimized plans (graphical & IPSA with different DTDC values) of ten cervical cancer patients were generated. Various DVH parameters like D90, V100, V150, V200, V300 were compared to evaluate the impact of DTDC on target coverage and high dose regions inside target for different plans. Similarly, for the OAR dose, values of D2cc were compared. Various planning parameters like CI, COIN, DHI, DNR, ODI, EI and gain factor (GF) for different OARs were calculated. Based on these indices a plan quality score (PQS) was formulated and calculated. PQS values were used to see the impact of DTDC on plan quality of IPSA in comparison with dosimetric quality of graphical plan. Results: We have found that target coverage is similar for IPSA and graphically optimized treatment plans. However, dose homogeneity was improved in IPSA compared to graphical optimization whereas conformality was better in graphically optimized plans. OAR dose was less in IPSA plans. High-dose regions inside the target were also reduced in IPSA comparatively. However, IPSA plans optimized with various values of DTDC did not necessarily reduce high-dose regions beyond 0.6. Plan quality scores (PQS) were 6.31, 6.31, 6.34, and 6.17 for the graphically optimized plan, IPSA with DTDC values of 0.0, 0.4, and 1.0 respectively. Conclusion: We found that IPSA is dosimetrically advantageous over graphical optimization. IPSA with a DTDC value of 0.4 improved overall plan quality. However, DTDC value beyond 0.6 produces dosimetrically sub-optimal plans hence the use of DTDC should be very selective and limited. © 2023 Société française de radiothérapie oncologique (SFRO)