SU-GG-T-146: Volumetric Modulated Arc Therapy (VMAT) for GBM Boost: The Impact of Multileaf Collimator Leaf Width and Calculation Grid on Planning Quality and Delivery Efficiency

2010 ◽  
Vol 37 (6Part17) ◽  
pp. 3218-3218
Author(s):  
D Schifter ◽  
S Al Ani ◽  
B Corn
Keyword(s):  
Volumetric Modulated Arc Therapy ◽  
Leaf Width ◽  
Multileaf Collimator ◽  
Arc Therapy ◽  
The Impact ◽  
Delivery Efficiency ◽  
Calculation Grid

Choice of appropriate beam model and gantry rotational angle for low-dose gradient-based craniospinal irradiation using volumetric-modulated arc therapy

2016 ◽  
Vol 16 (1) ◽  
pp. 53-64 ◽  
Author(s):  
Biplab Sarkar ◽  
Anirudh Pradhan
Keyword(s):  
Low Dose ◽  
Volumetric Modulated Arc Therapy ◽  
Craniospinal Irradiation ◽  
Leaf Width ◽  
Beam Model ◽  
Significant Difference ◽  
Arc Therapy ◽  
Prescription Dose ◽  
Flat Beam ◽  
The Impact

AbstractObjectivesWe aimed to assess the impact of advanced multileaf collimator (MLC) models and flattening filter-free (3F) beam in volumetric-modulated arc therapy (VMAT)-based craniospinal irradiation (CSI).MethodsCT scans of five medulloblastoma patients who previously received CSI at our hospital were used for the present study. Patients were planned for a prescription dose of 35 Gy to craniospinal axis. A three-dimensional conformal radiotherapy (3DCRT) plan and a VMAT plan using 1 cm MLC leaf width were generated as the gold standard (reference arm). Test VMAT plans were generated using Agility MLC model (MLC leaf width 5 mm) for various combinations of flattened beam (F) and 3F beam for treating the brain and spine planning target volume (PTV). Organs at risks (OARs) were analysed for dose 5, 50, 75 and 90% volumes, mean dose and maximum dose.ResultsAll 3DCRT plans and VMAT plans were aimed to cover 95% of PTV by at least 95% prescription dose. VMAT demonstrated lesser dose spillage than 3DCRT to body volume minus PTV (NTID: non tumor integral dose) for a dose threshold above 7·5 Gy. For the low-dose range (1–7 Gy), variation between the dose coverage between all VMAT plans (for either spine or brain PTV) was <1%. Intra-VMAT plan dose variation for all OAR’s for all tested parameters was <1 Gy. Average monitor unit (MU) difference among different VMAT plans ranged between 1·52 and 2·13 when normalised to 3DCRT MU. For VMAT plans, flat beam with 1 cm MLC showed the highest MU, whereas Agility MLC with 3F beam had the least MU values for intra-VMAT plans. No statistical significance variation (p) was observed in between reference arm and test arm plans except for mean dose and V107% for PTV spine. When compared between reference arm 3DCRT and test arm VMAT plans. For OAR’s, no statistical difference was observed between reference and test arm VMAT plans.ConclusionsReference arm plans and test arm plans exhibit no statistically significant difference. However, as compared with 3DCRT, VMAT plans are more conformal and produce lesser dose to OAR at the cost of higher delivered MU. 3F beams or finer width MLC’s (width <5 mm) have no advantage over the conventional 1 cm MLC and flat beam except that 3F beams have a shorter beam delivery time. This study demonstrate a significantly lesser spillage dose to NTID/body that of the reported literature, which is attributed to limited rotational arc length used for VMAT plans.

scholarly journals The impact of leaf width and plan complexity on DMLC tracking of prostate intensity modulated arc therapy

2013 ◽  
Vol 40 (11) ◽  
pp. 111717 ◽  
Author(s):  
Tobias Pommer ◽  
Marianne Falk ◽  
Per Rugaard Poulsen ◽  
Paul J. Keall ◽  
Ricky T. O’Brien ◽  
...  
Keyword(s):  
Leaf Width ◽  
Intensity Modulated ◽  
Arc Therapy ◽  
The Impact

Evaluation of the Impact of the Linac MLC and Gantry Sag in volumetric modulated arc therapy

2019 ◽  
Vol 46 (5) ◽  
pp. 1984-1994
Author(s):  
Thomas Milan ◽  
Garry Grogan ◽  
Martin A. Ebert ◽  
Pejman Rowshanfarzad
Keyword(s):  
Volumetric Modulated Arc Therapy ◽  
Arc Therapy ◽  
The Impact

scholarly journals Adjuvant volumetric modulated arc therapy compared to 3D conformal radiation therapy for newly diagnosed soft tissue sarcoma of the extremities: outcome and toxicity evaluation

2019 ◽  
Vol 92 (1102) ◽  
pp. 20190252 ◽  
Author(s):  
Lucia Di Brina ◽  
Antonella Fogliata ◽  
Pierina Navarria ◽  
Giuseppe D'Agostino ◽  
Ciro Franzese ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Soft Tissue ◽  
Soft Tissue Sarcoma ◽  
Total Dose ◽  
Surgical Resection ◽  
Local Control ◽  
Volumetric Modulated Arc Therapy ◽  
Conformal Radiation Therapy ◽  
Arc Therapy ◽  
The Impact

Objective: To assess the impact of adjuvant volumetric modulated arc therapy (VMAT) compared with three-dimensional conformal radiation therapy (3DCRT) in terms of toxicity and local control (LC) in patients with soft tissue sarcoma of the extremities. Methods: From 2004 to 2016, 109 patients were treated, initially using 3DCRT and subsequently with VMAT. Clinical outcome was evaluated by contrast-enhanced MRI, thoracic and abdominal CT 3 months after treatments and then every 6 months. Toxicity was evaluated with Common Terminology Criteria for Adverse Events scale v. 4.3. Results: Patients presented Stage III soft tissue sarcoma disease (77%), localized tumor (95%) at the lower extremity (87%), adipocytic histotype (46%). Surgical resection was performed in all patients, followed by adjuvant 3DCRT in 38, and VMAT in 71. The median total dose was 66 Gy/33 fractions (range 60–70 Gy;25–35 fractions). More successful bone sparing was recorded using VMAT (p < 0.001). Median follow-up was 61 months, 93 and 58 months for 3DCRT and VMAT group, respectively. The 2- and 5 year LC were 95.3±2.1%, and 87.4±3.4% for the whole cohort, 92.0±4.5%, 82.9±6.4% for 3DCRT, 97.1±2.0%, 89.6±4.1% for VMAT (p = 0.150). On univariate and multivariate analysis the factors recorded as conditioning LC were the status of the surgical resection margins (p = 0.028) and the total dose delivered (p = 0.013). Conclusion: The availability of modern radiotherapy technique permit a better conformity on the target with maximum sparing of normal tissue and acceptable side-effects. VMAT is a safe and feasible treatment with limited rate of toxicity, compared to 3DCRT. Results on LC of VMAT are encouraging. Advances in knowledge: Soft tissue sarcoma of the extremities can benefit from the use of VMAT, with a reduction of the high dose to bones to avoid radiation osteonecrosis. An adequate total dose of at least 66 Gy and a radical surgical margin allow a good local control.

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