Comparison of Elekta VMAT with helical tomotherapy and fixed field IMRT: Plan quality, delivery efficiency and accuracy

The purpose of this study was to evaluate and quantify the planning performance of SmartArc‐based volumetric‐modulated arc radiotherapy (VMAT) versus fixed‐beam intensity‐modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC) using a sequential mode treatment plan. The plan quality and performance of dual arc‐VMAT (DA‐VMAT) using the Pinnacle3 Smart‐Arc system (clinical version 9.0; Philips, Fitchburg, WI, USA) were evaluated and compared with those of seven‐field (7F)‐IMRT in 18 consecutive NPC patients. Analysis parameters included the conformity index (CI) and homogeneity index (HI) for the planning target volume (PTV), maximum and mean dose, normal tissue complication probability (NTCP) for the specified organs at risk (OARs), and comprehensive quality index (CQI) for an overall evaluation in the 11 OARs. Treatment delivery time, monitor units per fraction (MU/fr), and gamma (Γ3mm,3%) evaluations were also analyzed. DA‐VMAT achieved similar target coverage and slightly better homogeneity than conventional 7F‐IMRT with a similar CI and HI. NTCP values were only significantly lower in the left parotid gland (for xerostomia) for DA‐VMAT plans. The mean value of CQI at 0.98±0.02 indicated a 2% benefit in sparing OARs by DA‐VMAT. The MU/fr used and average delivery times appeared to show improved efficiencies in DA‐VMAT. Each technique demonstrated high accuracy in dose delivery in terms of a high‐quality assurance (QA) passing rate (>98%) of the (Γ3mm,3%) criterion. The major difference between DA‐VMAT and 7F‐IMRT using a sequential mode for treating NPC cases appears to be improved efficiency, resulting in a faster delivery time and the use of fewer MU/fr.PACS number: 87.53.Tf, 87.55.x, 87.55.D, 87.55.dk

Section: Methodsmentioning

confidence: 99%

Comparative analysis of SmartArc‐based dual arc volumetric‐modulated arc radiotherapy (VMAT) versus intensity‐modulated radiotherapy (IMRT) for nasopharyngeal carcinoma

Lee

Chao

Ting

et al. 2011

“…With regard to both improving tumor control by increase prescription target dose and reducing genitourinary and gastrointestinal toxicity by reducing the volumes of the rectal and bladder walls exposed to high‐dose levels, IMRT becomes the standard technique to deliver external beam radiation therapy treatment to the prostate 6 , 7 . Among IMRT techniques, fixed field IMRT (shorten for IMRT) is the most common radiotherapy technique for its accurate output dose 8 , 9 and easy quality assurance (10) …”

Section: Introductionmentioning

confidence: 99%

Dosimetric comparison of intensity‐modulated radiotherapy and volumetric‐modulated arc radiotherapy in patients with prostate cancer: a meta‐analysis

Ren

Sun

Liu

et al. 2016

Intensity‐modulated radiotherapy (IMRT) and volumetric‐modulated arc therapy (VMAT) are two main radiotherapy techniques. The aim of this study is to explore which is the preferred technique in prostate treatment through the related publications and meta‐analysis. Two authors independently identified all relevant articles available regarding eligibility criteria on PubMed, Embase, and Cochrane Library databases until December 2015. Publication bias was evaluated with funnel plot, and statistical analyses were performed with Stata software. P<0.05 was thought statistically significant. Ten studies comprised a total of 110 patients; in total 110 IMRT plans and 110 VMAT plans that were included in this study. V40, V60, and V70 of rectum were significantly decreased in VMAT than in IMRT. However, V50 of rectum and V40, V50, V60, V70 of bladder had no statistical differences between IMRI and VMAT plans. Compared with IMRT, the treatment time and MUs of VMAT were significantly lower. VMAT protects rectum better than IMRT and improves the delivery efficiency. VMAT may be the preferred modality for treating prostate cancer.PACS number(s): 87.55. D‐

“…A number of studies have investigated whether more advanced radiotherapy techniques, such as IMRT, would lead to better local control and lower doses to organs at risk (OARs) than standard RT. VMAT is a next generation of IMRT technique that can decrease treatment delivery times with similar or better plan quality for different treatment sites 2 , 3 , 4 , 5 …”

Section: Introductionmentioning

confidence: 99%

A pilot study of volumetric‐modulated arc therapy for malignant pleural mesothelioma

Cao

Wang

2016

Malignant pleural mesothelioma (MPM) is an extremely difficult disease to treat. This pilot study investigates the feasibility of using volumetric‐modulated arc therapy (VMAT) for malignant pleural mesothelioma (MPM), and compares VMAT to static field intensity‐modulated radiotherapy (IMRT) for five patients. To identify the best treatment technique for MPM, in five patients, we made a representative comparative analysis of two kinds of techniques for radiation therapy planning: IMRT and VMAT. The plans were created for an Elekta Synergy linear accelerator with 6 MV photons using Oncentra version 4.3 treatment planning system. Dose prescription was 50 Gy to the average of the planning target volume (PTV). PTV coverage and homogeneity, dose of organs at risk, numbers of segments, MUs, and delivery time were evaluated for all techniques. VMAT allowed better homogeneous and conformity indices compared with IMRT (HI=0.17 vs. 0.12, CI=0.64 vs. 0.77, respectively, p<0.05). VMAT plan had a significantly shorter delivery time (326 s) compared with in IMRT plans (510 s), (p<0.05). In the dose verification, an average of 93.16% of the detector points passed the 3%/3 mmγ criterion for VMAT plans, while in IMRT plans the dose verification was 95.12%.(p>0.05).PACS number(s): 87.55.D, 87.55.km, 87.56.Fc