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Title: Evaluation of Online/Offline Image Guidance/Adaptation Approaches for Prostate Cancer Radiation Therapy

Abstract

Purpose: To evaluate online/offline image-guided/adaptive treatment techniques for prostate cancer radiation therapy with daily cone-beam CT (CBCT) imaging. Methods and Materials: Three treatment techniques were evaluated retrospectively using daily pre- and posttreatment CBCT images on 22 prostate cancer patients. Prostate, seminal vesicles (SV), rectal wall, and bladder were delineated on all CBCT images. For each patient, a pretreatment intensity modulated radiation therapy plan with clinical target volume (CTV) = prostate + SV and planning target volume (PTV) = CTV + 3 mm was created. The 3 treatment techniques were as follows: (1) Daily Correction: The pretreatment intensity modulated radiation therapy plan was delivered after online CBCT imaging, and position correction; (2) Online Planning: Daily online inverse plans with 3-mm CTV-to-PTV margin were created using online CBCT images, and delivered; and (3) Hybrid Adaption: Daily Correction plus an offline adaptive inverse planning performed after the first week of treatment. The adaptive plan was delivered for all remaining 15 fractions. Treatment dose for each technique was constructed using the daily posttreatment CBCT images via deformable image registration. Evaluation was performed using treatment dose distribution in target and critical organs. Results: Treatment equivalent uniform dose (EUD) for the CTV was within [85.6%, 100.8%] of the pretreatment planned target EUD for Daily Correction;more » [98.7%, 103.0%] for Online Planning; and [99.2%, 103.4%] for Hybrid Adaptation. Eighteen percent of the 22 patients in Daily Correction had a target dose deficiency >5%. For rectal wall, the mean ± SD of the normalized EUD was 102.6% ± 2.7% for Daily Correction, 99.9% ± 2.5% for Online Planning, and 100.6% ± 2.1% for Hybrid Adaptation. The mean ± SD of the normalized bladder EUD was 108.7% ± 8.2% for Daily Correction, 92.7% ± 8.6% for Online Planning, and 89.4% ± 10.8% for Hybrid Adaptation. Conclusions: Both Online Planning and Hybrid Adaptation can achieve comparable target coverage and normal tissue sparing and are superior to the Daily Correction technique. The Daily Correction technique using a 3-mm target margin in the pretreatment plan is not appropriate to compensate for residual variations in CBCT image-guided prostate cancer radiation therapy.« less

Authors:
 [1];  [2];  [1];  [1]
  1. Department of Radiation Oncology, Beaumont Health System, Royal Oak, Michigan (United States)
  2. Department of Radiotherapy, Cancer Center, Sun Yat-sen University, Guangzhou (China)
Publication Date:
OSTI Identifier:
22458677
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Radiation Oncology, Biology and Physics; Journal Volume: 91; Journal Issue: 5; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; ANIMAL TISSUES; BIOMEDICAL RADIOGRAPHY; BLADDER; COMPARATIVE EVALUATIONS; COMPUTERIZED TOMOGRAPHY; CORRECTIONS; CRITICAL ORGANS; IMAGES; NEOPLASMS; PATIENTS; PLANNING; PROSTATE; RADIATION DOSE DISTRIBUTIONS; RADIATION DOSES; RADIOTHERAPY; RECTUM

Citation Formats

Qin, An, Sun, Ying, Liang, Jian, and Yan, Di, E-mail: dyan@beaumont.edu. Evaluation of Online/Offline Image Guidance/Adaptation Approaches for Prostate Cancer Radiation Therapy. United States: N. p., 2015. Web. doi:10.1016/J.IJROBP.2014.12.043.
Qin, An, Sun, Ying, Liang, Jian, & Yan, Di, E-mail: dyan@beaumont.edu. Evaluation of Online/Offline Image Guidance/Adaptation Approaches for Prostate Cancer Radiation Therapy. United States. doi:10.1016/J.IJROBP.2014.12.043.
Qin, An, Sun, Ying, Liang, Jian, and Yan, Di, E-mail: dyan@beaumont.edu. 2015. "Evaluation of Online/Offline Image Guidance/Adaptation Approaches for Prostate Cancer Radiation Therapy". United States. doi:10.1016/J.IJROBP.2014.12.043.
@article{osti_22458677,
title = {Evaluation of Online/Offline Image Guidance/Adaptation Approaches for Prostate Cancer Radiation Therapy},
author = {Qin, An and Sun, Ying and Liang, Jian and Yan, Di, E-mail: dyan@beaumont.edu},
abstractNote = {Purpose: To evaluate online/offline image-guided/adaptive treatment techniques for prostate cancer radiation therapy with daily cone-beam CT (CBCT) imaging. Methods and Materials: Three treatment techniques were evaluated retrospectively using daily pre- and posttreatment CBCT images on 22 prostate cancer patients. Prostate, seminal vesicles (SV), rectal wall, and bladder were delineated on all CBCT images. For each patient, a pretreatment intensity modulated radiation therapy plan with clinical target volume (CTV) = prostate + SV and planning target volume (PTV) = CTV + 3 mm was created. The 3 treatment techniques were as follows: (1) Daily Correction: The pretreatment intensity modulated radiation therapy plan was delivered after online CBCT imaging, and position correction; (2) Online Planning: Daily online inverse plans with 3-mm CTV-to-PTV margin were created using online CBCT images, and delivered; and (3) Hybrid Adaption: Daily Correction plus an offline adaptive inverse planning performed after the first week of treatment. The adaptive plan was delivered for all remaining 15 fractions. Treatment dose for each technique was constructed using the daily posttreatment CBCT images via deformable image registration. Evaluation was performed using treatment dose distribution in target and critical organs. Results: Treatment equivalent uniform dose (EUD) for the CTV was within [85.6%, 100.8%] of the pretreatment planned target EUD for Daily Correction; [98.7%, 103.0%] for Online Planning; and [99.2%, 103.4%] for Hybrid Adaptation. Eighteen percent of the 22 patients in Daily Correction had a target dose deficiency >5%. For rectal wall, the mean ± SD of the normalized EUD was 102.6% ± 2.7% for Daily Correction, 99.9% ± 2.5% for Online Planning, and 100.6% ± 2.1% for Hybrid Adaptation. The mean ± SD of the normalized bladder EUD was 108.7% ± 8.2% for Daily Correction, 92.7% ± 8.6% for Online Planning, and 89.4% ± 10.8% for Hybrid Adaptation. Conclusions: Both Online Planning and Hybrid Adaptation can achieve comparable target coverage and normal tissue sparing and are superior to the Daily Correction technique. The Daily Correction technique using a 3-mm target margin in the pretreatment plan is not appropriate to compensate for residual variations in CBCT image-guided prostate cancer radiation therapy.},
doi = {10.1016/J.IJROBP.2014.12.043},
journal = {International Journal of Radiation Oncology, Biology and Physics},
number = 5,
volume = 91,
place = {United States},
year = 2015,
month = 4
}
  • Purpose: To estimate the prevalence of rectal and urinary dysfunctional symptoms using image guided radiation therapy (IGRT) with fiducials and magnetic resonance planning for prostate cancer. Methods and Materials: During the implementation stages of IGRT between September 2008 and March 2010, 367 consecutive patients were treated with prostatic irradiation using 3-dimensional conformal radiation therapy with and without IGRT (non-IGRT). In November 2010, these men were asked to report their bowel and bladder symptoms using a postal questionnaire. The proportions of patients with moderate to severe symptoms in these groups were compared using logistic regression models adjusted for tumor and treatmentmore » characteristic variables. Results: Of the 282 respondents, the 154 selected for IGRT had higher stage tumors, received higher prescribed doses, and had larger volumes of rectum receiving high dosage than did the 128 selected for non-IGRT. The follow-up duration was 8 to 26 months. Compared with the non-IGRT group, improvement was noted in all dysfunctional rectal symptoms using IGRT. In multivariable analyses, IGRT improved rectal pain (odds ratio [OR] 0.07 [0.009-0.7], P=.02), urgency (OR 0.27 [0.11-0.63], P=<.01), diarrhea (OR 0.009 [0.02-0.35], P<.01), and change in bowel habits (OR 0.18 [0.06-0.52], P<.010). No correlation was observed between rectal symptom levels and dose-volume histogram data. Urinary dysfunctional symptoms were similar in both treatment groups. Conclusions: In comparison with men selected for non-IGRT, a significant reduction of bowel dysfunctional symptoms was confirmed in men selected for IGRT, even though they had larger volumes of rectum treated to higher doses.« less
  • Purpose: Kilovoltage intrafraction monitoring (KIM) is a new real-time 3-dimensional image guidance method. Unlike previous real-time image guidance methods, KIM uses a standard linear accelerator without any additional equipment needed. The first prospective clinical trial of KIM is underway for prostate cancer radiation therapy. In this paper we report on the measured motion accuracy and precision using real-time KIM-guided gating. Methods and Materials: Imaging and motion information from the first 200 fractions from 6 patient prostate cancer radiation therapy volumetric modulated arc therapy treatments were analyzed. A 3-mm/5-second action threshold was used to trigger a gating event where the beammore » is paused and the couch position adjusted to realign the prostate to the treatment isocenter. To quantify the in vivo accuracy and precision, KIM was compared with simultaneously acquired kV/MV triangulation for 187 fractions. Results: KIM was successfully used in 197 of 200 fractions. Gating events occurred in 29 fractions (14.5%). In these 29 fractions, the percentage of beam-on time, the prostate displacement was >3 mm from the isocenter position, reduced from 73% without KIM to 24% with KIM-guided gating. Displacements >5 mm were reduced from 16% without KIM to 0% with KIM. The KIM accuracy was measured at <0.3 mm in all 3 dimensions. The KIM precision was <0.6 mm in all 3 dimensions. Conclusions: Clinical implementation of real-time KIM image guidance combined with gating for prostate cancer eliminates large prostate displacements during treatment delivery. Both in vivo KIM accuracy and precision are well below 1 mm.« less
  • Purpose: To evaluate an online image-guidance strategy for conformal treatment of prostate cancer and to estimate margin-reduction benefits. Methods and Materials: Twenty-eight patients with at least 16 helical computed tomography scans were each used in this study. Two prostate soft-tissue registration methods, including sagittal rotation, were evaluated. Setup errors and rigid organ motion were corrected online; non-rigid and intrafraction motion were included in offline analysis. Various clinical target volume-planning target volume (CTV-PTV) margins were applied. Geometrical evaluations included analyses of isocenter shifts and rotations and overlap index. Dosimetric evaluations included minimum dose and equivalent uniform dose (EUD) for prostate andmore » gEUD for rectum. Results: Average isocenter shift and rotation were (dX,dY,dZ,{theta}) = (0.0 {+-} 0.7,-1.1 {+-} 4.0,-0.1 {+-} 2.5,0.7{sup o} {+-} 2.0{sup o}) mm. Prostate motion in anterior-posterior (AP) direction was significantly higher than superior-inferior and left-right (LR) directions. This observation was confirmed by isocenter shift in perspectives AP (1.8 {+-} 1.8 mm) and RL (3.7 {+-} 3.0 mm). Organ motion degrades target coverage and reduces doses to rectum. If 2% dose reduction on prostate D{sub 99} is allowed for 90% patients, then minimum 3 mm margins are necessary with ideal image registration. Conclusions: Significant margin reduction can be achieved through online image guidance. Certain margins are still required for nonrigid and intrafraction motion. To further reduce margin, a strategy that combines online geometric intervention and offline dose replanning is necessary.« less
  • Purpose: To evaluate the utility of intraprostatic markers in the treatment verification of prostate cancer radiotherapy. Specific aims were: to compare the effectiveness of offline correction protocols, either using gold markers or bony anatomy; to estimate the potential benefit of online correction protocol's using gold markers; to determine the presence and effect of intrafraction motion. Methods and Materials: Thirty patients with three gold markers inserted had pretreatment and posttreatment images acquired and were treated using an offline correction protocol and gold markers. Retrospectively, an offline protocol was applied using bony anatomy and an online protocol using gold markers. Results: Themore » systematic errors were reduced from 1.3, 1.9, and 2.5 mm to 1.1, 1.1, and 1.5 mm in the right-left (RL), superoinferior (SI), and anteroposterior (AP) directions, respectively, using the offline correction protocol and gold markers instead of bony anatomy. The subsequent decrease in margins was 1.7, 3.3, and 4 mm in the RL, SI, and AP directions, respectively. An offline correction protocol combined with an online correction protocol in the first four fractions reduced random errors further to 0.9, 1.1, and 1.0 mm in the RL, SI, and AP directions, respectively. A daily online protocol reduced all errors to <1 mm. Intrafraction motion had greater impact on the effectiveness of the online protocol than the offline protocols. Conclusions: An offline protocol using gold markers is effective in reducing the systematic error. The value of online protocols is reduced by intrafraction motion.« less
  • Purpose: To determine the target coverage for proton therapy with and without image guidance and daily prebeam reorientation. Methods and Materials: A total of 207 prostate positions were analyzed for 9 prostate cancer patients treated using our low-risk prostate proton therapy protocol (University of Florida Proton Therapy Institute 001). The planning target volume was defined as the prostate plus a 5-mm axial and 8-mm superoinferior extension. The prostate was repositioned using 5- and 10-mm shifts (anteriorly, inferiorly, posteriorly, and superiorly) and for Points A-D using a combination of 10-mm multidimensional movements (anteriorly or inferiorly; posteriorly or superiorly; and left ormore » right). The beams were then realigned using the new prostate position. The prescription dose was 78 Gray equivalent (GE) to 95% of the planning target volume. Results: For small movements in the anterior, inferior, and posterior directions within the planning target volume ({<=}5 mm), treatment realignment demonstrated small, but significant, improvements in the clinical target volume (CTV) coverage to the prescribed dose (78 GE). The anterior and posterior shifts also significantly increased the minimal CTV dose ({delta} +1.59 GE). For prostate 10-mm movements in the inferior, posterior, and superior directions, the beam realignment produced larger and significant improvements for both the CTV V{sub 78} ({delta} +6.4%) and the CTV minimal dose ({delta} +8.22 GE). For the compounded 10-mm multidimensional shifts, realignment significantly improved the CTV V{sub 78} ({delta} +11.8%) and CTV minimal dose ({delta} +23.6 GE). After realignment, the CTV minimal dose was >76.6 GE (>98%) for all points (A-D). Conclusion: Proton beam realignment after target shift will enhance CTV coverage for different prostate positions.« less