Comparison of dose calculated by an intensity modulated radiotherapy treatment planning system and an independent monitor unit verification program.

A comparison of isocenter dose calculated by a commercial intensity modulated radiation therapy treatment planning system and independent monitor unit verification calculation (MUVC) software was made. The percent disparity between the treatment plan and MUVC doses were calculated for 507 treatments (head and neck, prostate, abdomen, female pelvis, rectum and anus, and miscellaneous) from 303 patients. The MUVC calculated dose was, on average, 1.4% higher than the treatment planning dose, with a 1.2% standard deviation. The distribution of the disparities appeared to be Gaussian in shape with some variation by treatment site. Based on our analysis, disparities outside the range of +/-3% about the mean value should be checked and resolved prior to treatment delivery.

Haslam JJ ，Bonta DV ，Lujan AE ，Rash C ，Jackson W ，Roeske JC ... -  《Journal of Applied Clinical Medical Physics》

Comparison of monitor units calculated by radiotherapy treatment planning system and an independent monitor unit verification software.

In radiation therapy, the monitor units (MU) needed to deliver a treatment plan are calculated by treatment planning systems (TPS). The essential part of quality assurance is to verify the MU with independent monitor unit calculation to correct any potential errors prior to the start of treatment. In this study, we have compared the MU calculated by TPS and by independent MU verification software. The MU verification software was commissioned and tested for the data integrity to ensure that the correct beam data was considered for MU calculations. The accuracy of the calculations was tested by creating a series of test plans and comparing them with ion chamber measurements. The results show that there is good agreement between the two. The MU difference (MUdiff) between the monitor unit calculations of TPS and independent MU verification system was calculated for 623 fields from 245 patients and was analyzed by treatment site for head & neck, thorax, breast, abdomen and pelvis. The mean MUdiff of -0.838% with a standard deviation of 3.04% was observed for all 623 fields. The site specific standard deviation of MUdiff was as follows: abdomen and pelvis (<1.75%), head & neck (2.5%), thorax (2.32%) and breast (6.01%). The disparities were analyzed and different correction methods were used to reduce the disparity.

Sellakumar P ，Arun C ，Sanjay SS ，Ramesh SB ... -  《-》

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 ... -  《-》

Comparison of monitor unit calculations performed with a 3D computerized planning system and independent "hand" calculations: results of three years clinical experience.

Chan J ，Russell D ，Peters VG ，Farrell TJ ... -  《Journal of Applied Clinical Medical Physics》

A simple theoretical verification of monitor unit calculation for intensity modulated beams using dynamic mini-multileaf collimation.

Linthout N ，Verellen D ，Van Acker S ，Storme G ... -  《RADIOTHERAPY AND ONCOLOGY》