Volumetric modulated arc therapy for delivery of hypofractionated stereotactic lung radiotherapy: A dosimetric and treatment efficiency analysis
| Autor: | Inga S. Grills, Alvaro Martinez, Di Yan, Larry L. Kestin, Samuel McGrath, Martha M. Matuszak |
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| Rok vydání: | 2009 |
| Předmět: |
Male
Lung Neoplasms medicine.medical_treatment Planning target volume Imaging phantom Carcinoma Non-Small-Cell Lung Medicine Humans Radiology Nuclear Medicine and imaging Lung cancer Neoplasm Staging Lung business.industry Radiotherapy Planning Computer-Assisted Dose fractionation Hematology medicine.disease Volumetric modulated arc therapy Radiation therapy medicine.anatomical_structure Treatment Outcome Oncology Female Dose Fractionation Radiation Radiotherapy Intensity-Modulated business Nuclear medicine Dose rate |
| Zdroj: | Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. 95(2) |
| ISSN: | 1879-0887 |
| Popis: | Purpose/objective(s) Volumetric modulated arc therapy (VMAT) allows for intensity-modulated radiation delivery during gantry rotation with dynamic MLC motion, variable dose rates and gantry speed modulation. We compared VMAT plans with 3D-CRT for hypofractionated lung radiotherapy. Materials/methods Twenty-one 3D-CRT plans for Stage IA lung cancer previously treated stereotactically were selected. VMAT plans were generated by optimizing machine aperture shape and radiation intensity at 10° intervals. A partial arc range of 180° was manually selected to coincide with tumor location. The arc was resampled down to 5° intervals to ensure dose calculation accuracy. Identical planning objectives were used for VMAT/3D-CRT. Parameters assessed included dose to PTV and organs-at-risk (OAR), monitor units, and multiple conformity and homogeneity indices. Plans were delivered to a phantom for time comparison. Results Lung V20/12.5/10/5 were less with VMAT (relative reduction 4.5%, p = .02; 3.2%, p = .01; 2.6%, p = .01; 4.2%, p = .03, respectively). Mean/maximum-doses to PTV, dose to additional OARs, 95% isodose line conformity, and target volume homogeneity were equivalent. VMAT improved conformity at both the 80% (1.87 vs. 1.93, p = .08) and 50% isodose lines (5.19 vs. 5.65, p = .01). Treatment times were reduced significantly with VMAT (mean 6.1 vs. 11.9 min, p Conclusions Single arc VMAT planning achieves highly conformal dose distributions while controlling dose to critical structures, including significant reduction in lung dose volume parameters. Employing a VMAT technique decreases treatment times by 37–63%, reducing the chance of error introduced by intrafraction variation. The quality and efficiency of VMAT is ideally suited for stereotactic lung radiotherapy delivery. |
| Databáze: | OpenAIRE |
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