- Email: [email protected]
Current STAT Clinical Workflow and Proposed 30 Minute Scan, Plan, Treat STAT-RAD Workflow
S868
International Journal of Radiation Oncology Biology Physics
Conclusions: Field timeout automation is practicable and fits well into a clinical workflow. It improves patient throughput and is expected to improve patient safety. Author Disclosure: P. Sansourekidou: None. D. Pavord: None. V. Stakhursky: None. I. Lysiuk: O. Patent/License Fee/Copyright; Provisional patent application is submitted to United States Patent and Trademark Office. S. Kriminski: O. Patent/License Fee/Copyright; Provisional patent application is submitted to United States Patent and Trademark Office.
Conclusion: Our data shows that it is feasible to scan, plan, and begin treatment in 30 minutes with our proposed STAT-RAD workflow, and further innovation is underway to improve the quality of each step of the process. Author Disclosure: L. Handsfield: None. Q. Chen: None. S.H. Benedict: None. P.W. Read: None.
3723 Current STAT Clinical Workflow and Proposed 30 Minute Scan, Plan, Treat STAT-RAD Workflow L. Handsfield, Q. Chen, S.H. Benedict, and P.W. Read; University of Virginia, Charlottesville, VA Purpose/Objective(s): In the current external beam radiation oncology treatment process, a patient starts with a simulation CT and begins treatment about a week later. For Tomotherapy treatments, time is typically allotted to allow the beamlets to batch overnight and for the physicist to perform QA testing. One of our departmental goals is to develop an expedited treatment preparation workflow in which patients in pain or who have traveled long distances may receive treatment on their first day in the clinic. We currently have a phase II clinical trial open examining the implementation of a same-day treatment workflow for patients with painful osseous metastatic disease being treated on TomoTherapy. Here we present a workflow timeline comparison of our current one day STAT method and our proposed 30 minute method. Materials/Methods: Our current STAT workflow consists of performing all the necessary steps from patient CT to treatment in one day. In our proposed 30 minute STAT-RAD workflow, several of the steps are altered or replaced. A Tomotherapy MVCT is used for treatment planning instead of a conventional kV CT simulation to eliminate a step. Structures are transferred to the MVCT from a recent precontoured diagnostic MRI. The plan is calculated on a Tomotherapy GPU planning station which eliminates the time typically spent batching beamlets. Infrared cameras are employed to monitor the patient’s skin surface and any movement during treatment delivery. The novel expedited approach for pretreatment delivery QA includes an integrated strategy of MVCT exit detectors that perform a mini-fraction in-air QA while the patient is still on the table but outside of the bore. Measured or calculated time for MVCT, image fusion, and contour transfer are presented. A time comparison of the planning setup, optimization, and final calculation time for standard Tomotherapy planning versus a GPU based planning station was also preformed. Results: The MVCT image acquisition time was calculated to be approximately 10.7 minutes to cover the PTV plus an additional margin for planning. We were able to export the MVCT to a third party fusion and contouring software in approximately 32 seconds. It took an average of 6.5 minutes to register the MRI to the MVCT and only a few seconds to copy structures to the MVCT. For the six patients on trial, the average optimization time was 3 minutes and final calculation time was 42 seconds using a newly developed GPU treatment planning station, which is approximately 6-7 times faster than the standard planning times.
Poster Viewing Abstract 3724; Table
3724 Facilitating 3D Image Guided Treatment Planning of Shielded Tandem and Ovoid-based, Gynecological Brachytherapy Utilizing MVCT J. Kemp,1 M.J. Price,2,1 K.A. Gifford,3 B.C. Parker,4 B. Mason,5 L. Rechner,5 D. Neck,1 K. Ferachi,1 J. Gibbons,1 and K. Matthews6; 1Mary Bird Perkins Cancer Center, Baton Rouge, LA, 2University of North Carolina School of Medicine, Chapel Hill, NC, 3M.D. Anderson Cancer Center, Houston, TX, 4The University of Texas Medical Branch, Galveston, TX, 5MD Anderson, Houston, TX, 6Louisiana State University, Baton Rouge, LA Purpose/Objective(s): A drawback of tandem and ovoid (T&O) ICBT is exposure of the posterior bladder and anterior rectal walls to relatively high isodoses. To mitigate this effect, intra-ovoid shielding may be used to reduce dose to these OARs. However, metal artifacts present in images acquired via kVCT make anatomy segmentation and catheter localization difficult for the purpose of 3D treatment planning. We present a method that combines MVCT-based imaging and applicator modeling to increase the quality of 3D treatment plans for shielded T&O ICBT. Materials/Methods: Using the TPS, 9 medical physicists from multiple institutions performed organ segmentation and catheter reconstruction for KVCT and MVCT data sets acquired of a water phantom containing bladder and rectum surrogate structures and various HDR T&O applicators: CT/MR compatible (CTMR), shielded Fletcher Williamson (FW) and (3) shielded Fletcher-Suit-Delclos style (FSD). The dimensions of OAR structures were determined using in-air kVCT and physical measurements. By comparing the 3D volumes and point-to-perimeter (P2P) measurements of individual OAR contours, segmentation accuracy was assessed in regions exhibiting artifact under kVCT (1cm superior and inferior to shielding). Comparing the TPS-defined coordinate of the most distal dwell position to that of the true position (determined using radiographs of a fiducial affixed to the applicators), assessed catheter reconstruction accuracy. For some devices, this metric was also quantified using an applicator-model for localization. Results: Per the Table, the percentage of points (for P2P measurements) that differ from the true contour extents decrease under MVCT for the shielded T&Os (38.5 vs. 18.5%), while the converse is observed for the CTMR. Similarly, the volume of the OAR surrogates follows the same trend. This is attributed to the lack of metal artifacts as well as the decrease in the contrast of low Z materials observed when utilizing MVCT. Catheter reconstruction accuracy improved by 10% under MVCT for the CTMR, invariant for shielded T&Os and within 1.85mm of the true position using applicator modeling. Conclusions: Compared to kVCT, the quality of MVCT 3D ICBT treatment plans of shielded T&O is improved. Further improvements were observed when using an applicator model for catheter reconstruction.
Organ segmentation and catheter reconstruction results
Organ segmentation 2D/3D [0-2mm/0-10cc] CTMR-kV 85%/70% CTMR-MV 70%/60% FW-kV 62%/60% FW-MV 79%/50% FSD-kV 61%/50% FSD-MV 84%/50% Applicator modeling
Dwell localization in artifact region
[>2-3mm/>10-15cc]
[>3-5mm/>15-20cc]
[>5mm/>20cc]
[0-2mm]
[>2-3mm]
[>3-5mm]
[>5-10mm]
[>10mm]
13%/10% 16%/30% 11%/20% 11%/10% 16%/20% 6%/0% CTMR-kV/MV
2%/10% 6%/0% 6%/20% 8%/20% 17%/30% 4%/30% AVG (mm) Max (mm)
0%/10% 8%/40% 21%/0% 2%/20% 6%/0% 6%/20% 0.44/1.03 0.9/1.85
70% 90% 60% 50% 50% 50% FW-kV/MV
20% 10% 0% 20% 0% 20% AVG (mm) Max (mm)
0% 0% 30% 10% 30% 10% 0.58/0.52 1.49/1.32
10% 0% 10% 20% 10% 20%
0% 0% 0% 0% 10% 0%
International Journal of Radiation Oncology Biology Physics
Conclusions: Field timeout automation is practicable and fits well into a clinical workflow. It improves patient throughput and is expected to improve patient safety. Author Disclosure: P. Sansourekidou: None. D. Pavord: None. V. Stakhursky: None. I. Lysiuk: O. Patent/License Fee/Copyright; Provisional patent application is submitted to United States Patent and Trademark Office. S. Kriminski: O. Patent/License Fee/Copyright; Provisional patent application is submitted to United States Patent and Trademark Office.
Conclusion: Our data shows that it is feasible to scan, plan, and begin treatment in 30 minutes with our proposed STAT-RAD workflow, and further innovation is underway to improve the quality of each step of the process. Author Disclosure: L. Handsfield: None. Q. Chen: None. S.H. Benedict: None. P.W. Read: None.
3723 Current STAT Clinical Workflow and Proposed 30 Minute Scan, Plan, Treat STAT-RAD Workflow L. Handsfield, Q. Chen, S.H. Benedict, and P.W. Read; University of Virginia, Charlottesville, VA Purpose/Objective(s): In the current external beam radiation oncology treatment process, a patient starts with a simulation CT and begins treatment about a week later. For Tomotherapy treatments, time is typically allotted to allow the beamlets to batch overnight and for the physicist to perform QA testing. One of our departmental goals is to develop an expedited treatment preparation workflow in which patients in pain or who have traveled long distances may receive treatment on their first day in the clinic. We currently have a phase II clinical trial open examining the implementation of a same-day treatment workflow for patients with painful osseous metastatic disease being treated on TomoTherapy. Here we present a workflow timeline comparison of our current one day STAT method and our proposed 30 minute method. Materials/Methods: Our current STAT workflow consists of performing all the necessary steps from patient CT to treatment in one day. In our proposed 30 minute STAT-RAD workflow, several of the steps are altered or replaced. A Tomotherapy MVCT is used for treatment planning instead of a conventional kV CT simulation to eliminate a step. Structures are transferred to the MVCT from a recent precontoured diagnostic MRI. The plan is calculated on a Tomotherapy GPU planning station which eliminates the time typically spent batching beamlets. Infrared cameras are employed to monitor the patient’s skin surface and any movement during treatment delivery. The novel expedited approach for pretreatment delivery QA includes an integrated strategy of MVCT exit detectors that perform a mini-fraction in-air QA while the patient is still on the table but outside of the bore. Measured or calculated time for MVCT, image fusion, and contour transfer are presented. A time comparison of the planning setup, optimization, and final calculation time for standard Tomotherapy planning versus a GPU based planning station was also preformed. Results: The MVCT image acquisition time was calculated to be approximately 10.7 minutes to cover the PTV plus an additional margin for planning. We were able to export the MVCT to a third party fusion and contouring software in approximately 32 seconds. It took an average of 6.5 minutes to register the MRI to the MVCT and only a few seconds to copy structures to the MVCT. For the six patients on trial, the average optimization time was 3 minutes and final calculation time was 42 seconds using a newly developed GPU treatment planning station, which is approximately 6-7 times faster than the standard planning times.
Poster Viewing Abstract 3724; Table
3724 Facilitating 3D Image Guided Treatment Planning of Shielded Tandem and Ovoid-based, Gynecological Brachytherapy Utilizing MVCT J. Kemp,1 M.J. Price,2,1 K.A. Gifford,3 B.C. Parker,4 B. Mason,5 L. Rechner,5 D. Neck,1 K. Ferachi,1 J. Gibbons,1 and K. Matthews6; 1Mary Bird Perkins Cancer Center, Baton Rouge, LA, 2University of North Carolina School of Medicine, Chapel Hill, NC, 3M.D. Anderson Cancer Center, Houston, TX, 4The University of Texas Medical Branch, Galveston, TX, 5MD Anderson, Houston, TX, 6Louisiana State University, Baton Rouge, LA Purpose/Objective(s): A drawback of tandem and ovoid (T&O) ICBT is exposure of the posterior bladder and anterior rectal walls to relatively high isodoses. To mitigate this effect, intra-ovoid shielding may be used to reduce dose to these OARs. However, metal artifacts present in images acquired via kVCT make anatomy segmentation and catheter localization difficult for the purpose of 3D treatment planning. We present a method that combines MVCT-based imaging and applicator modeling to increase the quality of 3D treatment plans for shielded T&O ICBT. Materials/Methods: Using the TPS, 9 medical physicists from multiple institutions performed organ segmentation and catheter reconstruction for KVCT and MVCT data sets acquired of a water phantom containing bladder and rectum surrogate structures and various HDR T&O applicators: CT/MR compatible (CTMR), shielded Fletcher Williamson (FW) and (3) shielded Fletcher-Suit-Delclos style (FSD). The dimensions of OAR structures were determined using in-air kVCT and physical measurements. By comparing the 3D volumes and point-to-perimeter (P2P) measurements of individual OAR contours, segmentation accuracy was assessed in regions exhibiting artifact under kVCT (1cm superior and inferior to shielding). Comparing the TPS-defined coordinate of the most distal dwell position to that of the true position (determined using radiographs of a fiducial affixed to the applicators), assessed catheter reconstruction accuracy. For some devices, this metric was also quantified using an applicator-model for localization. Results: Per the Table, the percentage of points (for P2P measurements) that differ from the true contour extents decrease under MVCT for the shielded T&Os (38.5 vs. 18.5%), while the converse is observed for the CTMR. Similarly, the volume of the OAR surrogates follows the same trend. This is attributed to the lack of metal artifacts as well as the decrease in the contrast of low Z materials observed when utilizing MVCT. Catheter reconstruction accuracy improved by 10% under MVCT for the CTMR, invariant for shielded T&Os and within 1.85mm of the true position using applicator modeling. Conclusions: Compared to kVCT, the quality of MVCT 3D ICBT treatment plans of shielded T&O is improved. Further improvements were observed when using an applicator model for catheter reconstruction.
Organ segmentation and catheter reconstruction results
Organ segmentation 2D/3D [0-2mm/0-10cc] CTMR-kV 85%/70% CTMR-MV 70%/60% FW-kV 62%/60% FW-MV 79%/50% FSD-kV 61%/50% FSD-MV 84%/50% Applicator modeling
Dwell localization in artifact region
[>2-3mm/>10-15cc]
[>3-5mm/>15-20cc]
[>5mm/>20cc]
[0-2mm]
[>2-3mm]
[>3-5mm]
[>5-10mm]
[>10mm]
13%/10% 16%/30% 11%/20% 11%/10% 16%/20% 6%/0% CTMR-kV/MV
2%/10% 6%/0% 6%/20% 8%/20% 17%/30% 4%/30% AVG (mm) Max (mm)
0%/10% 8%/40% 21%/0% 2%/20% 6%/0% 6%/20% 0.44/1.03 0.9/1.85
70% 90% 60% 50% 50% 50% FW-kV/MV
20% 10% 0% 20% 0% 20% AVG (mm) Max (mm)
0% 0% 30% 10% 30% 10% 0.58/0.52 1.49/1.32
10% 0% 10% 20% 10% 20%
0% 0% 0% 0% 10% 0%