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Author Disclosure: B. Armbruster, None; A. de la Zerda, None; L. Xing, None. 2852 Optimizing Head and Neck Radiation Treatment Planning Using an IMRT Monoisocentric Technique with a Static Low Anterior Neck Field J. E. Kanke, M. A. Amin, P. Wong, K. K. Ang, A. S. Garden, W. H. Morrison, K. S. C. Chao, D. Rosenthal, P. Allen, S. J. Frank M.D. Anderson Cancer Center, Houston, TX Purpose/Objective(s): To evaluate and define the most appropriate head and neck treatment planning optimization method using an IMRT monoisocentric technique with a static low anterior neck field (LAN). Materials/Methods: Nodal levels IB -V were contoured as a clinical target volume (CTV) according to the RTOG head and neck atlas on the head and neck CT scan of ten patients at 3 mm intervals. Four millimeters of margin were added to the CTV to form a planning target volume (PTV) for treatment planning purposes prior to optimization. The isocenter on each plan was marked above the arytenoids on each patient’s CT scan, and half-beam asymmetric jaws were created for a match line with the LAN. The prescribed dose was 50 Gy. Each IMRT treatment plan was optimized a total of ten times; with the PTV on the CAX, and the PTV 3 mm, 6 mm, 9 mm, and 12mm above the CAX. The optimization was run with and without the LAN for each of the specified PTV volumes. Nine equal spaced treatment fields were used with Philips ADAC Pinnacle treatment planning system version 7.6 for IMRT planning assuming a Varian 120 multi-leaf collimator. Statistical analysis with Stata 9.1 was performed using the paired t-test, the nonparametric Wilcoxon matched-pairs signed-rank test, and the sign test to assess the equality of means. Results: The mean percent differences optimizing with the LAN “On” or “Off” for the right IB nodal region with PTV on CAX, 3 mm, 6 mm, 9 mm, and 12 mm above CAX were 12.4%, 2.2%, 1.5%, -0.1%, and 1.8% (p0.01, 0.04, 0.04, 0.72, and 0.01, respectively). The left level IB nodal regions mean percentage differences were 2.5%, 2.7%, 1.3%, 0.6%, and 1.6% (p0.02, 0.02, 0.09, 0.39, 0.02, respectively). The right level II nodal regions mean percentage differences with PTV on CAX, 3 mm, 6 mm, 9 mm, and 12 mm above CAX were 3.8%, 2.9%, 1.9%, 0.98%, and 2.33% (0.01, 0.01, 0.01, 0.04, and 0.01, respectively). The left level II nodal regions mean percentage differences were 4.0%, 3.0%, 1.9%, 1.3%, and 2.4% (p0.01, 0.01, 0.02, 0.02, and 0.01, respectively). The right level III nodal regions mean percentage differences with PTV on CAX, 3 mm, 6 mm, 9 mm, and 12 mm above CAX were 11.5%, 4.5%, 2.9%, 0.2%, and -0.01% (p0.01, 0.01, 0.01, 0.07, and 0.07, respectively). The left level III nodal regions mean percentage differences were 9.9%, 4.8%, 2.9%, 0.4%, and 0.2% (p0.03, 0.01, 0.001, 0.66, and 0.83, respectively). The mean percentage differences for both right and left level IV nodal regions were consistantly 1% for any optimization with the PTV above CAX. The right level V nodal regions mean percentage differences with PTV on CAX, 3 mm, 6 mm, 9 mm, and 12 mm above CAX were 6.7%, 10.8%, 1.0%, -0.7%, and 0.01% (p0.01, 0.01, 0.01, 0.07, and 0.07, respectively). The left level V nodal regions mean percentage differences were -5.2%, 11.8%, 1.0%, -0.4%, and 0.2% (p0.07, 0.01, 0.01, 0.07, and 0.07, respectively). Conclusions: Head and neck cancer treatment planning using an IMRT monoisocentric technique is best optimized by including the static LAN with the PTV removed at CAX and one CT slice above CAX. Optimization with the PTV starting at 6 –9 mm above the CAX results in the most homogeneous isodose distribution. Author Disclosure: J.E. Kanke, None; M.A. Amin, None; P. Wong, None; K.K. Ang, None; A.S. Garden, None; W.H. Morrison, None; K.S.C. Chao, None; D. Rosenthal, None; P. Allen, None; S.J. Frank, None. 2853 Dose Painting Using Energy and Intensity Modulated Proton Therapy J. Fan, J. Li, W. Luo, T. Lin, Z. Chen, C. Ma Fox Chase Cancer Center, Philadelphia, PA Purpose/Objective(s): Dose painting, the ability to identify sub-volumes of the treatment target that contain clonogenic and/or hypoxic tumor cells and then deliver some additional dose restricted to those volumes, is becoming possible by incorporating S691 Proceedings of the 48th Annual ASTRO Meeting
Transcript of 2852
Author Disclosure: B. Armbruster, None; A. de la Zerda, None; L. Xing, None.
2852 Optimizing Head and Neck Radiation Treatment Planning Using an IMRT Monoisocentric Techniquewith a Static Low Anterior Neck Field
J. E. Kanke, M. A. Amin, P. Wong, K. K. Ang, A. S. Garden, W. H. Morrison, K. S. C. Chao, D. Rosenthal, P. Allen,S. J. Frank
M.D. Anderson Cancer Center, Houston, TX
Purpose/Objective(s): To evaluate and define the most appropriate head and neck treatment planning optimization methodusing an IMRT monoisocentric technique with a static low anterior neck field (LAN).
Materials/Methods: Nodal levels IB -V were contoured as a clinical target volume (CTV) according to the RTOG head andneck atlas on the head and neck CT scan of ten patients at 3 mm intervals. Four millimeters of margin were added to the CTVto form a planning target volume (PTV) for treatment planning purposes prior to optimization. The isocenter on each plan wasmarked above the arytenoids on each patient’s CT scan, and half-beam asymmetric jaws were created for a match line with theLAN. The prescribed dose was 50 Gy. Each IMRT treatment plan was optimized a total of ten times; with the PTV on the CAX,and the PTV 3 mm, 6 mm, 9 mm, and 12mm above the CAX. The optimization was run with and without the LAN for eachof the specified PTV volumes. Nine equal spaced treatment fields were used with Philips ADAC Pinnacle treatment planningsystem version 7.6 for IMRT planning assuming a Varian 120 multi-leaf collimator. Statistical analysis with Stata 9.1 wasperformed using the paired t-test, the nonparametric Wilcoxon matched-pairs signed-rank test, and the sign test to assess theequality of means.
Results: The mean percent differences optimizing with the LAN “On” or “Off” for the right IB nodal region with PTV on CAX,3 mm, 6 mm, 9 mm, and 12 mm above CAX were 12.4%, 2.2%, 1.5%, -0.1%, and 1.8% (p�0.01, 0.04, 0.04, 0.72, and 0.01,respectively). The left level IB nodal regions mean percentage differences were 2.5%, 2.7%, 1.3%, 0.6%, and 1.6% (p�0.02,0.02, 0.09, 0.39, 0.02, respectively). The right level II nodal regions mean percentage differences with PTV on CAX, 3 mm,6 mm, 9 mm, and 12 mm above CAX were 3.8%, 2.9%, 1.9%, 0.98%, and 2.33% (0.01, 0.01, 0.01, 0.04, and 0.01, respectively).The left level II nodal regions mean percentage differences were 4.0%, 3.0%, 1.9%, 1.3%, and 2.4% (p�0.01, 0.01, 0.02, 0.02,and 0.01, respectively). The right level III nodal regions mean percentage differences with PTV on CAX, 3 mm, 6 mm, 9 mm,and 12 mm above CAX were 11.5%, 4.5%, 2.9%, 0.2%, and -0.01% (p�0.01, 0.01, 0.01, 0.07, and 0.07, respectively). Theleft level III nodal regions mean percentage differences were 9.9%, 4.8%, 2.9%, 0.4%, and 0.2% (p�0.03, 0.01, �0.001, 0.66,and 0.83, respectively). The mean percentage differences for both right and left level IV nodal regions were consistantly � 1%for any optimization with the PTV above CAX. The right level V nodal regions mean percentage differences with PTV on CAX,3 mm, 6 mm, 9 mm, and 12 mm above CAX were 6.7%, 10.8%, 1.0%, -0.7%, and 0.01% (p�0.01, 0.01, 0.01, 0.07, and 0.07,respectively). The left level V nodal regions mean percentage differences were -5.2%, 11.8%, 1.0%, -0.4%, and 0.2% (p�0.07,0.01, 0.01, 0.07, and 0.07, respectively).
Conclusions: Head and neck cancer treatment planning using an IMRT monoisocentric technique is best optimized byincluding the static LAN with the PTV removed at CAX and one CT slice above CAX. Optimization with the PTV starting at6–9 mm above the CAX results in the most homogeneous isodose distribution.
Author Disclosure: J.E. Kanke, None; M.A. Amin, None; P. Wong, None; K.K. Ang, None; A.S. Garden, None; W.H.Morrison, None; K.S.C. Chao, None; D. Rosenthal, None; P. Allen, None; S.J. Frank, None.
2853 Dose Painting Using Energy and Intensity Modulated Proton Therapy
J. Fan, J. Li, W. Luo, T. Lin, Z. Chen, C. Ma
Fox Chase Cancer Center, Philadelphia, PA
Purpose/Objective(s): Dose painting, the ability to identify sub-volumes of the treatment target that contain clonogenic and/orhypoxic tumor cells and then deliver some additional dose restricted to those volumes, is becoming possible by incorporating
S691Proceedings of the 48th Annual ASTRO Meeting
