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Title: SU-E-T-139: Dynamic Conformal Arcs Vs. VMAT for Stereotactic Lung Target Treatment Planning

Purpose: To investigate if Dynamic Conformal Arcs (DCA) can be used to achieve similar target coverage and conformality as that of using VMAT for Stereotactic Body Radiation Therapy (SBRT) for Lung cases. Methods: We retrospectively re-planned 11 patients that were treated with SBRT for lung tumors using only a single conformal arc, broken into three or four arc segments and weighted differentially in order to achieve the dosimetric constraints as outlined in RTOG 0915 protocol. These re-plans of using DCA were compared with those of using VMAT in terms of the Planning Tumor Volume (PTV) coverage goals, Maximum Dose 2 cm away (D {sub 2}cm), High Dose Spillage, Intermediate Dose Spillage, Lung volume getting 5 Gy (V{sub 5}), and number of monitor units (MU). Results: Of the 11 cases, only three DCA plans failed the D{sub 2}cm parameter, and one VMAT plan failed. None of the 11 patients failed the High Dose Spillage in either technique. For Intermediate Dose Spillage, one DCA plan failed and none failed for VMAT plans. The average V{sub 5} for DCA was 10.5 percent, with VMAT reporting 11.7 percent. The average number of MU for DCA and VMAT were 2605 and 3451, respectively. Conclusion: DCAmore » is able to achieve very similar treatment planning goals as that of using VMAT in treating SBRT Lung tumors in most cases with simplicity. In addition, the DCA technique produces an acceptable plan with lower V{sub 5} in less MU when dose to OAR concerns are at minimum. However, DCA has shown its limitations when the target is close to multiple OAR.« less
Authors:
; ;  [1]
  1. Vanderbilt University, Nashville, TN (United States)
Publication Date:
OSTI Identifier:
22339893
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 41; Journal Issue: 6; Other Information: (c) 2014 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; CASE METHOD; COMPARATIVE EVALUATIONS; LIMITING VALUES; LUNGS; NEOPLASMS; PATIENTS; PLANNING; RADIATION DOSES; RADIATION MONITORS; RADIOTHERAPY