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Program Information

Robust Planning Techniques Using Pinnacle3 TPS IMPT Module


K Jordan

K Jordan1*, (1) Philips Healthcare, Fitchburg, WI

Presentations

MO-RPM-GePD-TT-5 (Monday, July 31, 2017) 3:45 PM - 4:15 PM Room: Therapy ePoster Theater


Purpose: To identify qualitative & quantitative methods & results for planning & planning robustly with Pinnacle3 TPS IMPT module.

Methods: Pinnacle3 TPS IMPT planning is now available in P16 release. The P16 proton licensing also features robust analyis, robust optimization & it's own proprietary optimizer. This poster looks to identify techniques for qualitatively & quantitatively utilizing these tools for improved planning.

Results: Using robust analysis tool correctly provides qualitative feedback using 4 available variables: range uncertainty, and x, y, & z certainty; thus creating 9 plans (+/- each variable & the nominal scenario). The 2up viewer qualitatively & correctly provides user feedback to make plan assessment on PTVs & OARs on a voxel level and the DVH tool allows for qualitative assessment. For example, 3% range error for an AP beam can be found to modulate 3% over/under with respect to PTV and he 2up viewer quickly shows this result. Quantitatively, for example 32cm range nominal beam will look to show 97% x 32 = 31.04cm and 103% x 32 = 32.96cm. A prostate case at 60Gy/20# with parallel opposed Lateral beams with 3% range error will show 59.86Gy(RBE) nominal mean dose to PTV60, while 3% overshoot will provide 67.14Gy(RBE) mean dose and 3% undershoot will provide 51.09Gy(RBE) mean dose respectively. By applying RO, the nominal will show 60.26Gy(RBE), the 3% overshoot will show 61Gy(RBE), and the 3% undershoot will show 57.00Gy(RBE) all with respect to PTV60; thus tightening the gap between nominal & range uncertainties and providing confidence in prescribed dose under this error example. The bladder & rectum OARs have acceptable statistics for all scenarios without RO and thus provide further confidence to planner using RO.

Conclusion: Robust techniques in Pinnacle3 TPS adequately provide feedback using robust analysis tool and closed loop application using robust optimization.

Funding Support, Disclosures, and Conflict of Interest: I am a physicist employed by Philips Healthcare


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