Search

Byline: Bharath. Pandu, D. Khanna, P. Mohandass, Hima. Ninan, Rajadurai. Elavarasan, Saro. Jacob, Goutham. Sunny Purpose: The aim of the current study is to commission compensator-based total body irradiation (TBI) [...]

Byline: Raghavendra. Holla, D. Khanna, Bhaskaran. Pillai, K. Jafar Ali, P. Renil Mon, C. Clinto, Tharmarnadar. Ganesh Purpose: An experimental method using the linear portion of the relative film dose-response [...]

Byline: Raghavendra. Holla, D. Khanna, Shubhangi. Barsing, Bhaskaran. Pillai, Tharmarnadar. Ganesh Aims and Objectives: The influence of target motion on the reconstructed internal target volume (ITV) for device-based (DB) external [...]

Objective: The aim of this study is to implement a new treatment technique in total body irradiation (TBI) using the manual field-in-field-TBI (MFIF-TBI) technique and dosimetrically verifying its results with respect to compensator-based TBI (CB-TBI) and open field TBI technique. Materials and Methods: A rice flour phantom (RFP) was placed on TBI couch with knee bent position at 385 cm source to surface distance. Midplane depth (MPD) was calculated for skull, umbilicus, and calf regions by measuring separations. Three subfields were opened manually for different regions using the multi-leaf collimator and jaws. The treatment Monitor unit (MU) was calculated based on each subfield size. In the CB-TBI technique, Perspex was used as a compensator. Treatment MU was calculated using MPD of umbilicus region and the required compensator thickness was calculated. For open field TBI, treatment MU was calculated using MPD of umbilicus region, and the treatment was executed without placing compensator. The diodes were placed on the surface of RFP to measure the delivered dose and the results were compared. Results: The MFIF-TBI results showed that the deviation was within ± 3.0% for the different regions, except for the neck for which the deviation was 8.72%. In the CB-TBI delivery, the dose deviation was ± 3.0% for different regions in the RFP. The open field TBI results showed that the dose deviation was not within the limit ± 10.0%. Conclusion: The MFIF-TBI technique can be implemented for TBI treatment as no TPS is required, and laborious process of making a compensator can be avoided while ensuring that the dose uniformity in all the regions within the tolerance limit. [ABSTRACT FROM AUTHOR]

Byline: P. Mohandass, D. Khanna, T. Kumar, T. Thiyagaraj, C. Saravanan, Narendra. Bhalla, Abhishek. PuriPurpose: This study compared three different methods used in registering cone-beam computed tomography (CBCT) image set [...]

Byline: P. Mohandass, D. Khanna, D. Manigandan, Narendra. Bhalla, Abhishek. Puri Purpose: Validation of a new software version of a Monte Carlo treatment planning system through comparing plans generated by [...]

Purpose: Validation of a new software version of a Monte Carlo treatment planning system through comparing plans generated by two software versions in volumetric-modulated arc therapy (VMAT) for lung cancer. Materials and Methods: Three patients who were treated with 60 Gy/30 fractions in Elekta Synergy™ linear accelerator by VMAT technique with 2% statistical uncertainty (SU) were chosen for the study. Multiple VMAT plans were generated using two different software versions of Monaco treatment planning system TPS (V5.10.02 and V5.11). By keeping all other parameters constant, originally accepted plans were recalculated for the SUs of 0.5%, 1%, 2%, 3%, 4%, and 5%. For plan evaluation, the metrics compared were conformity Index (CI), homogeneity Index (HI), dose coverage to planning target volume (PTV), organ at risk (OAR) doses to spinal cord, pericardium, bilateral lungs-PTV, esophagus, liver, normal tissue integral dose (NTID), volumes receiving dose >5 and >10 Gy, calculation time (tCT), and gamma pass rates. Results: In both versions, CI and HI improved as the SU increased from 0.5% to 5%. No significant dose difference was observed in Dmean to PTV, bilateral lungs-PTV, pericardium, esophagus, liver, normal tissue volume receiving >5, and >10 Gy and NTID. It was observed that while the tCT and gamma pass rates decreased, the maximum dose to PTV increased as the SU increased. No other significant dose differences were observed between the two MC versions compared. Conclusion: For lung VMAT plans, in both versions, SU could be accepted up to 3% per plan with reduced tCT without compromising plan quality and deliverability by accepting variations in point dose and an inhomogeneous dose within the target. The plan quality of Monaco™V5.10.02 was similar to Monaco™TPS-V5.11 except for tCT. [ABSTRACT FROM AUTHOR]