Comparison between In-house developed and Diamond commercial software for patient specific independent monitor unit calculation and verification with heterogeneity corrections.

The study was aimed to compare two different monitor unit (MU) or dose verification software in volumetric modulated arc therapy (VMAT) using modified Clarkson's integration technique for 6 MV photons beams. In-house Excel Spreadsheet based monitor unit verification calculation (MUVC) program and PTW's DIAMOND secondary check software (SCS), version-6 were used as a secondary check to verify the monitor unit (MU) or dose calculated by treatment planning system (TPS). In this study 180 patients were grouped into 61 head and neck, 39 thorax and 80 pelvic sites. Verification plans are created using PTW OCTAVIUS-4D phantom and also measured using 729 detector chamber and array with isocentre as the suitable point of measurement for each field. In the analysis of 154 clinically approved VMAT plans with isocentre at a region above -350 HU, using heterogeneity corrections, In-house Spreadsheet based MUVC program and Diamond SCS showed good agreement TPS. The overall percentage average deviations for all sites were (-0.93% + 1.59%) and (1.37% + 2.72%) for In-house Excel Spreadsheet based MUVC program and Diamond SCS respectively. For 26 clinically approved VMAT plans with isocentre at a region below -350 HU showed higher variations for both In-house Spreadsheet based MUVC program and Diamond SCS. It can be concluded that for patient specific quality assurance (QA), the In-house Excel Spreadsheet based MUVC program and Diamond SCS can be used as a simple and fast accompanying to measurement based verification for plans with isocentre at a region above -350 HU.

Kuppusamy V ，Nagarajan V ，Jeevanandam P ，Murugan L ... -  《-》

In-house spread sheet based monitor unit verification program for volumetric modulated arc therapy.

Independent monitor unit verification calculation (MUVC) has been recommended by several authors for intensity modulated radiotherapy (IMRT) as a patient specific quality assurance tool. Aim of the present work is to develop an in-house excel spread sheet based MUVC program for volumetric modulated arc therapy (VMAT) using Clarkson's integration technique. Total scatter factor (S(c,p)) and tissue maximum ratio (TMR) for circular fields obtained from Treatment planning system (TPS) were used for the calculation. Multileaf collimator (MLC) interleaf leakage, MLC round edge transmission and tongue and groove effect were accounted. MUVC calculation was performed for 58 patients both for patient anatomy and for homogenous cylindrical phantom. Radiological path lengths were used as water equivalent depths (WED) for calculations using patient anatomy. Monitor unit (MU) discrepancies between -2.60% and 0.28% with mean deviation of -0.92% ± 0.75% were obtained for homogenous cylindrical phantom calculations. MUVC for patient anatomy resulted in large variations between -19.02% and 0.67% for 14 plans where isocenter was at a region below -350 HU. But For 44 plans where the isocenter was at a region above -350 HU, variations between -3.44% and 0.48% were obtained with mean deviation of -1.73% ± 1.12%. For VMAT patient specific quality assurance, the independent MUVC algorithm can be used as an easy and quick auxiliary to measurement based verification for plans with isocenter at a region above -350 HU.

Jeevanandam P ，Rajasekaran D ，Sukumar P ，Nagarajan V ... -  《-》

Validation and clinical implementation of commercial secondary check software with heterogeneity corrections.

Kuppusamy V ，Nagarajan V ，Murugan L 《-》

Time-resolved dosimetry using a pinpoint ionization chamber as quality assurance for IMRT and VMAT.

Louwe RJ ，Wendling M ，Monshouwer R ，Satherley T ，Day RA ，Greig L ... -  《-》

Patient-specific IMRT verification using independent fluence-based dose calculation software: experimental benchmarking and initial clinical experience.

Georg D ，Stock M ，Kroupa B ，Olofsson J ，Nyholm T ，Ahnesjö A ，Karlsson M ... -  《PHYSICS IN MEDICINE AND BIOLOGY》