1
|
Huijskens S, Granton P, Fremeijer K, van Wanrooij C, Offereins-van Harten K, Schouwenaars-van den Beemd S, Hoogeman MS, Sattler MGA, Penninkhof J. Clinical practicality and patient performance for surface-guided automated VMAT gating for DIBH breast cancer radiotherapy. Radiother Oncol 2024; 195:110229. [PMID: 38492672 DOI: 10.1016/j.radonc.2024.110229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/11/2024] [Accepted: 03/12/2024] [Indexed: 03/18/2024]
Abstract
BACKGROUND AND PURPOSE To evaluate the performance of automated surface-guided gating for left-sided breast cancer with DIBH and VMAT. MATERIALS AND METHODS Patients treated in the first year after introduction of DIBH with VMAT were retrospectively considered for analysis. With automated surface-guided gating the beam automatically switches on/off, if the surface region of interest moved in/out the gating tolerance (±3 mm, ±3°). Patients were coached to hold their breath as long as comfortably possible. Depending on the patient's preference, patients received audio instructions during treatment delivery. Real-time positional variations of the breast/chest wall surface with respect to the reference surface were collected, for all three orthogonal directions. The durations and number of DIBHs needed to complete dose delivery, and DIBH position variations were determined. To evaluate an optimal gating window threshold, smaller tolerances of ±2.5 mm, ±2.0 mm, and ±1.5 mm were simulated. RESULTS 525 fractions from 33 patients showed that median DIBH duration was 51 s (range: 30-121 s), and median 4 DIBHs per fraction were needed to complete VMAT dose delivery. Median intra-DIBH stability and intrafractional DIBH reproducibility approximated 1.0 mm in each direction. No large differences were found between patients who preferred to perform the DIBH procedure with (n = 21) and without audio-coaching (n = 12). Simulations demonstrated that gating window tolerances could be reduced from ±3.0 mm to ±2.0 mm, without affecting beam-on status. CONCLUSION Independent of the use of audio-coaching, this study demonstrates that automated surface-guided gating with DIBH and VMAT proved highly efficient. Patients' DIBH performance far exceeded our expectations compared to earlier experiences and literature. Furthermore, gating window tolerances could be reduced.
Collapse
Affiliation(s)
- Sophie Huijskens
- Erasmus MC Cancer Institute, University Medical Center Rotterdam, Department of Radiotherapy, Rotterdam, the Netherlands.
| | - Patrick Granton
- Erasmus MC Cancer Institute, University Medical Center Rotterdam, Department of Radiotherapy, Rotterdam, the Netherlands
| | - Kimm Fremeijer
- Erasmus MC Cancer Institute, University Medical Center Rotterdam, Department of Radiotherapy, Rotterdam, the Netherlands
| | - Cynthia van Wanrooij
- Erasmus MC Cancer Institute, University Medical Center Rotterdam, Department of Radiotherapy, Rotterdam, the Netherlands
| | - Kirsten Offereins-van Harten
- Erasmus MC Cancer Institute, University Medical Center Rotterdam, Department of Radiotherapy, Rotterdam, the Netherlands
| | | | - Mischa S Hoogeman
- Erasmus MC Cancer Institute, University Medical Center Rotterdam, Department of Radiotherapy, Rotterdam, the Netherlands
| | - Margriet G A Sattler
- Erasmus MC Cancer Institute, University Medical Center Rotterdam, Department of Radiotherapy, Rotterdam, the Netherlands
| | - Joan Penninkhof
- Erasmus MC Cancer Institute, University Medical Center Rotterdam, Department of Radiotherapy, Rotterdam, the Netherlands
| |
Collapse
|
2
|
Rudat V, Shi Y, Zhao R, Yu W. Setup margins based on the inter- and intrafractional setup error of left-sided breast cancer radiotherapy using deep inspiration breath-hold technique (DIBH) and surface guided radiotherapy (SGRT). J Appl Clin Med Phys 2024; 25:e14271. [PMID: 38273673 PMCID: PMC11163505 DOI: 10.1002/acm2.14271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 10/27/2023] [Accepted: 12/29/2023] [Indexed: 01/27/2024] Open
Abstract
PURPOSE The use of volumetric modulated arc therapy (VMAT), simultaneous integrated boost (SIB), and hypofractionated regimen requires adequate patient setup accuracy to achieve an optimal outcome. The purpose of this study was to assess the setup accuracy of patients receiving left-sided breast cancer radiotherapy using deep inspiration breath-hold technique (DIBH) and surface guided radiotherapy (SGRT) and to calculate the corresponding setup margins. METHODS The patient setup accuracy between and within radiotherapy fractions was measured by comparing the 6DOF shifts made by the SGRT system AlignRT with the shifts made by kV-CBCT. Three hundred and three radiotherapy fractions of 23 left-sided breast cancer patients using DIBH and SGRT were used for the analysis. All patients received pre-treatment DIBH training and visual feedback during DIBH. An analysis of variance (ANOVA) was used to test patient setup differences for statistical significance. The corresponding setup margins were calculated using the van Herk's formula. RESULTS The intrafractional patient setup accuracy was significantly better than the interfractional setup accuracy (p < 0.001). The setup margin for the combined inter- and intrafractional setup error was 4, 6, and 4 mm in the lateral, longitudinal, and vertical directions if based on SGRT alone. The intrafractional error contributed ≤1 mm to the calculated setup margins. CONCLUSION With SGRT, excellent intrafractional and acceptable interfractional patient setup accuracy can be achieved for the radiotherapy of left-sided breast cancer using DIBH and modern radiation techniques. This allows for reducing the frequency of kV-CBCTs, thereby saving treatment time and radiation exposure.
Collapse
Affiliation(s)
- Volker Rudat
- Department of Radiation OncologyJiahui International Cancer Center Shanghai, Jiahui HealthShanghaiChina
| | - Yanyan Shi
- Department of Radiation OncologyJiahui International Cancer Center Shanghai, Jiahui HealthShanghaiChina
| | - Ruping Zhao
- Department of Radiation OncologyJiahui International Cancer Center Shanghai, Jiahui HealthShanghaiChina
| | - Wei Yu
- Department of Radiation OncologyJiahui International Cancer Center Shanghai, Jiahui HealthShanghaiChina
| |
Collapse
|
3
|
Buschmann M, Kauer-Dorner D, Konrad S, Georg D, Widder J, Knäusl B. Stereoscopic X-ray image and thermo-optical surface guidance for breast cancer radiotherapy in deep inspiration breath-hold. Strahlenther Onkol 2024; 200:306-313. [PMID: 37796341 DOI: 10.1007/s00066-023-02153-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 08/30/2023] [Indexed: 10/06/2023]
Abstract
PURPOSE To investigate the feasibility of a thermo-optical surface imaging (SGRT) system combined with room-based stereoscopic X‑ray image guidance (IGRT) in a dedicated breast deep inspiration breath-hold (DIBH) irradiation workflow. In this context, benchmarking of portal imaging (EPID) and cone-beam CT (CBCT) against stereoscopic X‑rays was performed. METHODS SGRT + IGRT data of 30 left-sided DIBH breast patients (1 patient with bilateral cancer) treated in 351 fractions using thermo-optical surface imaging and X-ray IGRT were retrospectively analysed. Patients were prepositioned based on a free-breathing surface reference derived from a CT scan. Once the DIBH was reached using visual feedback, two stereoscopic X‑ray images were acquired and registered to the digitally reconstructed radiographs derived from the DIBH CT. Based on this registration, a couch correction was performed. Positioning and monitoring by surface and X-ray imaging were verified by protocol-based EPID or CBCT imaging at selected fractions and the calculation of residual geometric deviations. RESULTS The median X‑ray-derived couch correction vector was 4.9 (interquartile range [IQR] 3.3-7.1) mm long. Verification imaging was performed for 134 fractions (216 RT field verifications) with EPID and for 37 fractions with CBCT, respectively. The median 2D/3D deviation vector length over all verification images was 2.5 (IQR 1.6-3.9) mm/3.4 (IQR 2.2-4.8) mm for EPID/CBCT, both being well within the planning target volume (PTV) margins (7 mm). A moderate correlation (0.49-0.65) was observed between the surface signal and X-ray position in DIBH. CONCLUSION DIBH treatments using thermo-optical SGRT and X-ray IGRT were feasible for breast cancer patients. Stereoscopic X‑ray positioning was successfully verified by standard IGRT techniques.
Collapse
Affiliation(s)
- Martin Buschmann
- Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/AKH Wien, Währinger Gürtel 18-20, Vienna, 1090, Austria
| | - Daniela Kauer-Dorner
- Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/AKH Wien, Währinger Gürtel 18-20, Vienna, 1090, Austria
| | - Stefan Konrad
- Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/AKH Wien, Währinger Gürtel 18-20, Vienna, 1090, Austria
| | - Dietmar Georg
- Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/AKH Wien, Währinger Gürtel 18-20, Vienna, 1090, Austria
| | - Joachim Widder
- Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/AKH Wien, Währinger Gürtel 18-20, Vienna, 1090, Austria
| | - Barbara Knäusl
- Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/AKH Wien, Währinger Gürtel 18-20, Vienna, 1090, Austria.
| |
Collapse
|
4
|
Mankinen M, Virén T, Seppälä J, Koivumäki T. Interfractional variation in whole-breast VMAT irradiation: a dosimetric study with complementary SGRT and CBCT patient setup. Radiat Oncol 2024; 19:21. [PMID: 38347554 PMCID: PMC10863193 DOI: 10.1186/s13014-024-02418-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 02/05/2024] [Indexed: 02/15/2024] Open
Abstract
BACKGROUND The dosimetric effect of setup uncertainty and tissue deformations in left-sided whole-breast irradiation with complementary surface-guided radiotherapy (SGRT) and cone-beam computed tomography (CBCT) setup was evaluated. METHOD Treatment courses of 40.05 Gy prescribed dose in 15 fractions were simulated for 29 patients by calculating the dose on deformed CT images, that were based on daily CBCT images, and deforming and accumulating the dose onto the planning CT image. Variability in clinical target volume (CTV) position and shape was assessed as the 95% Hausdorff distance (HD95) between the planning CTV and deformed CTV structures. DVH metrics were evaluated between the planned and simulated cumulative dose distributions using two treatment techniques: tangential volumetric modulated arc therapy (tVMAT) and conventional 3D-conformal radiotherapy (3D-CRT). RESULTS Based on the HD95 values, the variations in CTV shape and position were enclosed by the 5 mm CTV-PTV margin in 85% of treatment fractions using complementary CBCT and SGRT setup. A residual error of 8.6 mm was observed between the initial SGRT setup and CBCT setup. The median CTV V95% coverage was 98.1% (range 93.1-99.8%) with tVMAT and 98.2% (range 84.5-99.7%) with 3D-CRT techniques with CBCT setup. With the initial SGRT-only setup, the corresponding coverages were 96.3% (range 92.6-99.4%) and 96.6% (range 84.2-99.4%), respectively. However, a considerable bias in vertical residual error between initial SGRT setup and CBCT setup was observed. Clinically relevant changes between the planned and cumulative doses to organs-at-risk (OARs) were not observed. CONCLUSIONS The CTV-to-PTV margin should not be reduced below 5 mm even with daily CBCT setup. Both tVMAT and 3D-CRT techniques were robust in terms of dose coverage to the target and OARs. Based on the shifts between setup methods, CBCT setup is recommended as a complementary method with SGRT.
Collapse
Affiliation(s)
- M Mankinen
- Deparment of Physics, University of Jyväskylä (JYU), Survontie 9 C, 40014, Jyväskylä, Finland.
- Deparment of Medical Physics, Hospital Nova of Central Finland, Wellbeing Services County of Central Finland, Jyväskylä, Finland.
| | - T Virén
- Center of Oncology, Kuopio University Hospital (KUH), The Wellbeing Services Country of North Savo, Kuopio, Finland
| | - J Seppälä
- Center of Oncology, Kuopio University Hospital (KUH), The Wellbeing Services Country of North Savo, Kuopio, Finland
| | - T Koivumäki
- Deparment of Physics, University of Jyväskylä (JYU), Survontie 9 C, 40014, Jyväskylä, Finland
- Deparment of Medical Physics, Hospital Nova of Central Finland, Wellbeing Services County of Central Finland, Jyväskylä, Finland
| |
Collapse
|
5
|
Lu W, Hong LX, Yamada N, Berry SL, Song Y, Choi W, Cerviño LI, Tang X, Mechalakos JG, Romesser PB, Powell S, Li G. Comparison of setup accuracy of optical surface image versus orthogonal x-ray images for VMAT of the left breast using deep-inspiration breath-hold. J Appl Clin Med Phys 2023; 24:e14117. [PMID: 37535396 PMCID: PMC10691624 DOI: 10.1002/acm2.14117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/25/2023] [Accepted: 07/18/2023] [Indexed: 08/04/2023] Open
Abstract
To compare the setup accuracy of optical surface image (OSI) versus orthogonal x-ray images (2DkV) using cone beam computed tomography (CBCT) as ground truth for radiotherapy of left breast cancer in deep-inspiration breath-hold (DIBH). Ten left breast DIBH patients treated with volumetric modulated arc therapy (VMAT) were studied retrospectively. OSI, 2DkV, and CBCT were acquired weekly at treatment setup. OSI, 2DkV, and CBCT were registered to planning CT or planning DRR based on a breast surface region of interest (ROI), bony anatomy (chestwall and sternum), and both bony anatomy and breast surface, respectively. These registrations provided couch shifts for each imaging system. The setup errors, or the difference in couch shifts between OSI and CBCT were compared to those between 2DkV and CBCT. A second OSI was acquired during last beam delivery to evaluate intrafraction motion. The median absolute setup errors were (0.21, 0.27, 0.23 cm, 0.6°, 1.3°, 1.0°) for OSI, and (0.26, 0.24, 0.18 cm, 0.9°, 1.0°, 0.6°) for 2DkV in vertical, longitudinal and lateral translations, and in rotation, roll and pitch, respectively. None of the setup errors was significantly different between OSI and 2DkV. For both systems, the systematic and random setup errors were ≤0.6 cm and ≤1.5° in all directions. Nevertheless, larger setup errors were observed in some sessions in both systems. There was no correlation between OSI and CBCT whereas there was modest correlation between 2DkV and CBCT. The intrafraction motion in DIBH detected by OSI was small with median absolute translations <0.2 cm, and rotations ≤0.4°. Though OSI showed comparable and small setup errors as 2DkV, it showed no correlation with CBCT. We concluded that to achieve accurate setup for both bony anatomy and breast surface, daily 2DkV can't be omitted following OSI for left breast patients treated with DIBH VMAT.
Collapse
Affiliation(s)
- Wei Lu
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Linda X. Hong
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Nelson Yamada
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Sean L. Berry
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Yulin Song
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Wookjin Choi
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Laura I. Cerviño
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Xiaoli Tang
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - James G. Mechalakos
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Paul B. Romesser
- Department of Radiation OncologyMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Simon Powell
- Department of Radiation OncologyMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Guang Li
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| |
Collapse
|
6
|
Zeng C, Fan Q, Li X, Song Y, Kuo L, Aristophanous M, Cervino LI, Hong L, Powell S, Li G. A Potential Pitfall and Clinical Solutions in Surface-Guided Deep Inspiration Breath Hold Radiation Therapy for Left-Sided Breast Cancer. Adv Radiat Oncol 2023; 8:101276. [PMID: 38047221 PMCID: PMC10692299 DOI: 10.1016/j.adro.2023.101276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 05/18/2023] [Indexed: 12/05/2023] Open
Abstract
Purpose Deep inspiration breath hold (DIBH) is an effective technique to spare the heart in treating left-sided breast cancer. Surface-guided radiation therapy (SGRT) is increasingly applied in DIBH setup and motion monitoring. Patient-specific breathing behavior, either thoracically driven or abdominally driven (A-DIBH), should be unaltered, online identified, and monitored accordingly to ensure reproducible heart-sparing treatment. Methods and Materials Sixty patients with left-sided breast cancer treated with SGRT were analyzed: 20 A-DIBH patients with vertical chest elevation (VCE ≤ 5 mm) were prospectively identified, and 40 control patients were retrospectively and randomly selected for comparison. At simulation, both free-breathing (FB) and DIBH computed tomography (CT) were acquired, guided by a motion surrogate placed around the xiphoid process. For SGRT treatment setups, the region of interest (ROI) was defined on the CT chest surface, and the surrogate-based setup was a backup. For all 60 patients, the VCE was measured as the average of the FB-to-DIBH elevations at the breast and xiphoid process, together with abdominal elevation. In the 40-patient control group, A-DIBH patients (VCE ≤ 5 mm) were identified. Of the 20 A-DIBH patients, 10 were treated with volumetric modulated arc therapy plans, and 10 patients were treated with tangent plans. Clinical DIBH plans were recalculated on FB CT to compare maximum dose (DMax), 5% of the maximum dose (D5%), mean dose (DMean), and V30Gy, V20Gy, and V5Gy of the heart and lungs and their significance. Results In the 20 A-DIBH patients, VCE = 3 ± 2 mm, surrogate motion (9 ± 6 mm), and abdomen motion of 14 ± 5 mm are found. Heart dose reduction from FB to DIBH is significant (P < .01): ∆DMax = -8.4 ± 9.8 Gy, ∆D5% = -2.4 ± 4.4 Gy, and ∆DMean = -0.6 ± 0.9 Gy. Six out of 40 control patients (15%) are found to have VCE ≤ 5 mm. Conclusions A-DIBH (VCE ≤ 5 mm) patient population is significant (15%), and they should be identified in the SGRT workflow and monitored accordingly. A new abdominal ROI or an abdominal surrogate should be used instead of the conventional chest-only ROI. Patient-specific DIBH should be preserved for higher reproducibility to ensure heart sparing.
Collapse
Affiliation(s)
- Chuan Zeng
- Departments of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Qiyong Fan
- Departments of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Xiang Li
- Departments of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Yulin Song
- Departments of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Licheng Kuo
- Departments of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Michalis Aristophanous
- Departments of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Laura I. Cervino
- Departments of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Linda Hong
- Departments of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Simon Powell
- Departments of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Guang Li
- Departments of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| |
Collapse
|
7
|
Psarras M, Stasinou D, Stroubinis T, Protopapa M, Zygogianni A, Kouloulias V, Platoni K. Surface-Guided Radiotherapy: Can We Move on from the Era of Three-Point Markers to the New Era of Thousands of Points? Bioengineering (Basel) 2023; 10:1202. [PMID: 37892932 PMCID: PMC10604452 DOI: 10.3390/bioengineering10101202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/10/2023] [Accepted: 10/14/2023] [Indexed: 10/29/2023] Open
Abstract
The surface-guided radiotherapy (SGRT) technique improves patient positioning with submillimeter accuracy compared with the conventional positioning technique of lasers using three-point tattoos. SGRT provides solutions to considerations that arise from the conventional setup technique, such as variability in tattoo position and the psychological impact of the tattoos. Moreover, SGRT provides monitoring of intrafractional motion. PURPOSE This literature review covers the basics of SGRT systems and examines whether SGRT can replace the traditional positioning technique. In addition, it investigates SGRT's potential in reducing positioning times, factors affecting SGRT accuracy, the effectiveness of live monitoring, and the impact on patient dosage. MATERIALS AND METHODS This study focused on papers published from 2016 onward that compared SGRT with the traditional positioning technique and investigated factors affecting SGRT accuracy and effectiveness. RESULTS/CONCLUSIONS SGRT provides the same or better results regarding patient positioning. The implementation of SGRT can reduce overall treatment time. It is an effective technique for detecting intrafraction patient motion, improving treatment accuracy and precision, and creating a safe and comfortable environment for the patient during treatment.
Collapse
Affiliation(s)
- Michalis Psarras
- Medical Physics Unit, 2nd Department of Radiology, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, 124 62 Athens, Greece
- Department of Radiation Oncology and Stereotactic Radiosurgery, Mediterraneo Hospital, 166 75 Athens, Greece
| | - Despoina Stasinou
- Department of Radiation Oncology and Stereotactic Radiosurgery, Mediterraneo Hospital, 166 75 Athens, Greece
| | - Theodoros Stroubinis
- Department of Radiation Oncology and Stereotactic Radiosurgery, Mediterraneo Hospital, 166 75 Athens, Greece
| | - Maria Protopapa
- Department of Radiation Oncology and Stereotactic Radiosurgery, Mediterraneo Hospital, 166 75 Athens, Greece
| | - Anna Zygogianni
- Radiation Oncology Unit, 1st Department of Radiology, Aretaieion University Hospital, Medical School, National and Kapodistrian University of Athens, 115 28 Athens, Greece
| | - Vassilis Kouloulias
- Radiation Oncology Unit, 2nd Department of Radiology, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, 124 62 Athens, Greece
| | - Kalliopi Platoni
- Medical Physics Unit, 2nd Department of Radiology, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, 124 62 Athens, Greece
- Department of Radiation Oncology and Stereotactic Radiosurgery, Mediterraneo Hospital, 166 75 Athens, Greece
| |
Collapse
|
8
|
Zhao H, Sarkar V, Paxton A, Huang YJ, Haacke C, Price RG, Frances Su FC, Szegedi M, Rassiah P, Salter B. Technical note: Clinical evaluation of a newly released surface-guided radiation therapy system on DIBH for left breast radiation therapy. Med Phys 2023; 50:5978-5986. [PMID: 37683108 DOI: 10.1002/mp.16699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 08/08/2023] [Accepted: 08/13/2023] [Indexed: 09/10/2023] Open
Abstract
BACKGROUND It has been shown that a significant reduction of mean heart dose and left anterior descending artery (LAD) dose can be achieved through the use of DIBH for left breast radiation therapy. Surface-guided DIBH has been widely adopted during the last decade, and there are mainly three commercially available SGRT systems. The reports of the performance of a newly released SGRT system for DIBH application are currently very limited. PURPOSE To evaluate the clinical performance of a newly released SGRT system on DIBH for left breast radiation therapy. METHODS Twenty-five left breast cancer patients treated with DIBH utilizing Varian's Identify system were included (total 493-fraction treatments). Four aspects of the clinical performance were evaluated: Identify offsets of free breathing post patient setup from tattoos, Identify offsets during DIBH, Identify agreement with radiographic ports during DIBH, and DIBH reference surface re-capture post patient shifts. The systematic and random errors of free breathing Identify offsets post patient setup were calculated for each patient, as well as for offsets during DIBH. Radiographic ports were taken when the patient's DIBH position was within the clinical tolerance of (± 0.3 cm, ± 30 ), and these were then compared with treatment field DRRs. If the ports showed that the patient alignment did not agree with the DRRs within 3 mm, a patient shift was performed. A new reference surface was captured and verification ports were taken. RESULTS The all-patient average systematic and random errors of Identify offsets for free breathing were within (0.4 cm, 1.50 ) post tattoo setup. The maximum per-patient systematic and random errors were (1.1 cm, 6.20 ) and (0.9 cm, 20 ), and the maximum amplitude of Identify offsets were (2.59 cm, 90 ). All 493-fraction DIBH treatments were delivered and successfully guided by the Identify SGRT system. The systematic and random errors of Identify offsets for DIBH were within (0.2 cm, 2.30 ). Seven patients needed re-captured surface references due to surface variation or position shifts based on the ports. All patient DIBH verification ports guided by Identify were approved by attending physicians. CONCLUSION This evaluation showed that the Identify system performed effectively for surface-guided patient setup and surface-guided DIBH imaging and treatment delivery. The feature of color-coded real-time patient surface matching feedback facilitated the evaluation of the patient alignment accuracy and the adjustment of the patient position to match the reference.
Collapse
Affiliation(s)
- Hui Zhao
- Department of Radiation Oncology, University of Utah, Salt Lake City, Utah, USA
| | - Vikren Sarkar
- Department of Radiation Oncology, University of Utah, Salt Lake City, Utah, USA
| | - Adam Paxton
- Department of Radiation Oncology, University of Utah, Salt Lake City, Utah, USA
| | - Y Jessica Huang
- Department of Radiation Oncology, University of Utah, Salt Lake City, Utah, USA
| | - Christine Haacke
- Department of Radiation Oncology, University of Utah, Salt Lake City, Utah, USA
| | - Ryan G Price
- Department of Radiation Oncology, University of Utah, Salt Lake City, Utah, USA
| | - Fan-Chi Frances Su
- Department of Radiation Oncology, University of Texas Southwestern, Dallas, Texas, USA
| | - Martin Szegedi
- Department of Radiation Oncology, University of Utah, Salt Lake City, Utah, USA
| | - Prema Rassiah
- Department of Radiation Oncology, University of Utah, Salt Lake City, Utah, USA
| | - Bill Salter
- Department of Radiation Oncology, University of Utah, Salt Lake City, Utah, USA
| |
Collapse
|
9
|
Sasaki M, Matsushita N, Fujimoto T, Nakata M, Ono Y, Yoshimura M, Mizowaki T. New patient setup procedure using surface-guided imaging to reduce body touch and skin marks in whole-breast irradiation during the COVID-19 pandemic. Radiol Phys Technol 2023; 16:422-429. [PMID: 37474738 DOI: 10.1007/s12194-023-00735-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/14/2023] [Accepted: 07/15/2023] [Indexed: 07/22/2023]
Abstract
This study aimed to assess the effectiveness of a new patient-setup procedure using surface-guided imaging during the coronavirus disease 2019 (COVID-19) pandemic for left-sided whole-breast irradiation with deep inspiration breath-hold. Two setup procedures were compared regarding patient positioning accuracy for the first 22 patients. The first was a traditional setup (T-setup) procedure that used a surface-guided system after patient setup with traditional skin marks and lasers. The second procedure involved a new setup (N-setup) that used only a surface-guided system. The positioning accuracy of the remaining 23 patients was assessed using a setup that combined marker reduction and the N-setup procedure. No significant difference was observed in positioning accuracy between the two setups. The positioning accuracy of the marker-reduction setup was within 3 mm in all directions. The N-setup procedure may be a useful strategy for preventing infection during or after the COVID-19 pandemic.
Collapse
Affiliation(s)
- Makoto Sasaki
- Division of Clinical Radiology Service, Kyoto University Hospital, 54 Kawahara-Cho, Shogoin, Sakyo-Ku, Kyoto, Kyoto, 606-8507, Japan.
| | - Norimasa Matsushita
- Division of Clinical Radiology Service, Kyoto University Hospital, 54 Kawahara-Cho, Shogoin, Sakyo-Ku, Kyoto, Kyoto, 606-8507, Japan
| | - Takahiro Fujimoto
- Division of Clinical Radiology Service, Kyoto University Hospital, 54 Kawahara-Cho, Shogoin, Sakyo-Ku, Kyoto, Kyoto, 606-8507, Japan
| | - Manabu Nakata
- Division of Clinical Radiology Service, Kyoto University Hospital, 54 Kawahara-Cho, Shogoin, Sakyo-Ku, Kyoto, Kyoto, 606-8507, Japan
| | - Yuka Ono
- Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Michio Yoshimura
- Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Takashi Mizowaki
- Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| |
Collapse
|
10
|
Dekker J, Essers M, Verheij M, Kusters M, de Kruijf W. Dose coverage and breath-hold analysis of breast cancer patients treated with surface-guided radiotherapy. Radiat Oncol 2023; 18:72. [PMID: 37081477 PMCID: PMC10116713 DOI: 10.1186/s13014-023-02261-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 04/10/2023] [Indexed: 04/22/2023] Open
Abstract
BACKGROUND Surface-guided radiotherapy (SGRT) is used to ensure a reproducible patient set-up and for intra-fraction motion monitoring. The arm position of breast cancer patients is important, since this is related to the position of the surrounding lymph nodes. The aim of the study was to investigate the set-up accuracy of the arm of patients positioned using SGRT. Moreover, the actual delivered dose was investigated and an extensive breath-hold analysis was performed. METHODS 84 patients who received local or locoregional breast radiation therapy were positioned and monitored using SGRT. The accuracy of the arm position, represented by the clavicle position, was studied on the anterior-posterior kV-image. To investigate the effect of changes in anatomy and patient set-up, the actual delivered dose was calculated on cone-beam CT-scans (CBCT). A deformable registration of the CT to the CBCT was applied to deform the structures of the CT onto the CBCT. The minimum dose in percentage of the prescribed dose that was received by 98% of different CTV volumes (D98) was determined. An extensive breath-hold analysis was performed and definitions for relevant parameters were given. RESULTS The arm position of 77 out of 84 patients in total was successful, based on the clavicle rotation. The mean clavicle rotation was 0.4° (± 2.0°). For 89.8% of the patients who were irradiated on the whole-breast D98 was larger than 95% of the prescribed dose (D98 > 95%). D98 > 95% applied for 70.8% of the patients irradiated on the chest wall. Concerning the lymph node CTVs, D98 > 95% for at least 95% of the patients. The breath-hold analysis showed a mean residual setup error of - 0.015 (± 0.90), - 0.18 (± 0.82), - 0.58 (± 1.1) mm in vertical, lateral, and longitudinal direction, respectively. The reproducibility and stability of the breath-hold was good, with median 0.60 mm (95% confidence interval (CI) [0.66-0.71] mm) and 0.20 mm (95% CI 0.21-0.23] mm), respectively. CONCLUSIONS Using SGRT we were able to position breast cancer patients successfully, with focus on the arm position. The actual delivered dose calculated on the CBCT was adequate and no relation between clavicle rotation and actual delivered dose was found. Moreover, breath-hold analysis showed a good reproducibility and stability of the breath-hold. Trial registration CCMO register NL69214.028.19.
Collapse
Affiliation(s)
- Janita Dekker
- Instituut Verbeeten, Klinische fysica & instrumentatie, Postbus 90120, 5000 LA, Tilburg, The Netherlands.
| | - Marion Essers
- Instituut Verbeeten, Klinische fysica & instrumentatie, Postbus 90120, 5000 LA, Tilburg, The Netherlands
| | - Marcel Verheij
- Department of Radiation Oncology, Radboud University Medical Center, Geert Grooteplein 32, 6525 GA, Nijmegen, The Netherlands
| | - Martijn Kusters
- Department of Radiation Oncology, Radboud University Medical Center, Geert Grooteplein 32, 6525 GA, Nijmegen, The Netherlands
| | - Willy de Kruijf
- Instituut Verbeeten, Klinische fysica & instrumentatie, Postbus 90120, 5000 LA, Tilburg, The Netherlands
| |
Collapse
|
11
|
Nguyen D, Khodri M, Sporea C, Reinoso R, Jacob Y, Farah J. Investigating the robustness of the AlignRT InBore™ co-calibration process and determining the overall tracking errors. Phys Med 2023; 108:102567. [PMID: 36996575 DOI: 10.1016/j.ejmp.2023.102567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 02/05/2023] [Accepted: 03/18/2023] [Indexed: 03/30/2023] Open
Abstract
OBJECTIVE To determine the overall tracking errors inherent to the co-calibration procedure of AlignRT InBore™'s (Vision RT Ltd., London, UK) ceiling-mounted and ring-mounted cameras. METHODS Extrinsic calibration errors related to the mismatch between ceiling and InBore cameras' isocentres and treatment isocentre were determined using MV images and the SRS package and compared to traditional plate-based error. Next, using a realistic anthropomorphic female phantom, intrinsic calibration errors were determined while varying source-skin distance (80 to 100 cm), breast board inclination (0° to 12.5°), room lighting conditions (0 to 258 lx), skin colour (dark, white and natural skin colour), and pod occlusion. RESULTS MV images of the cube proved plate-based calibration to suffer from large errors especially in the vertical direction (up to 2 mm). Intrinsic calibration errors were considerably lower. Indeed, RTD values of ceiling and InBore cameras showed little variability with isocentre depth (within 1.0 mm/0.4°), surface orientation and breast board inclination (within 0.7 mm/0.3°), changing lighting conditions (within 0.1 mm/0.2°), skin colour/tone (within 0.3 mm/0.3°) and camera pod occlusion (within 0.3 mm/0.2°). CONCLUSION The use of MV-images proved critical to maintain co-calibrating errors of ceiling and InBore cameras to Halcyon's treatment isocentre below 1 mm.
Collapse
|
12
|
Nguyen D, Reinoso R, Farah J, Yossi S, Lorchel F, Passerat V, Louet E, Pouchard I, Khodri M, Barbet N. Reproducibility of surface-based deep inspiration breath-hold technique for lung stereotactic body radiotherapy on a closed-bore gantry linac. Phys Imaging Radiat Oncol 2023; 26:100448. [PMID: 37252251 PMCID: PMC10213090 DOI: 10.1016/j.phro.2023.100448] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 05/05/2023] [Accepted: 05/09/2023] [Indexed: 05/31/2023] Open
Abstract
Background and purpose Tumor motion and delivery efficiency are two main challenges of lung stereotactic body radiotherapy (SBRT). The present work implemented the deep inspiration breath hold technique (DIBH) with surface guided radiation therapy (SGRT) on closed-bore linacs and investigated the correlation between SGRT data and internal target position. Materials and methods Thirteen lung SBRT patients treated in DIBH using a closed-bore gantry linac and a ring-mounted SGRT system were retrospectively analysed. Visual coaching was used to achieve DIBH with a ± 1 mm threshold window in the anterior-posterior direction. Three kV-CBCTs were added to the treatment workflow and examined offline to verify intra-fraction tumor position. Surface-based DIBH was analysed using SGRT treatment reports and an in-house python script. Data from 73 treatment sessions and 175 kV-CBCTs were studied. Correlations between target and surface positions were studied with Linear Mixed Models. Results Median intra-fraction tumor motion was 0.8 mm (range: 0.7-1.3 mm) in the anterior-posterior direction, 1.2 mm (range: 1-1.7 mm) in the superior-inferior direction, and 1 mm (range: 0.7-1.1 mm) in the left-right direction, with rotations of <1° (range: 0.6°-1.1°) degree in all three directions. Planned target volumes and healthy lung volumes receiving 12.5 Gy and 13.5 Gy were reduced on average by 67% and 54%, respectively. Conclusions Lung SBRT in DIBH with the ring-mounted SGRT system proved reproducible. The surface monitoring provided by SGRT was found to be a reliable surrogate for internal target motion. Moreover, the implementation of DIBH technique helped reduce target volumes and lung doses.
Collapse
Affiliation(s)
- Daniel Nguyen
- ORLAM’s Group, Department of Radiation Oncology, Mâcon, Villeurbanne, Lyon, France
| | - Rebeca Reinoso
- ORLAM’s Group, Department of Radiation Oncology, Mâcon, Villeurbanne, Lyon, France
| | - Jad Farah
- Vision RT Ltd., Dove House, Arcadia Avenue, London N3 2JU, United Kingdom
| | - Sena Yossi
- ORLAM’s Group, Department of Radiation Oncology, Mâcon, Villeurbanne, Lyon, France
| | - Fabrice Lorchel
- ORLAM’s Group, Department of Radiation Oncology, Mâcon, Villeurbanne, Lyon, France
| | - Victor Passerat
- ORLAM’s Group, Department of Radiation Oncology, Mâcon, Villeurbanne, Lyon, France
| | - Estelle Louet
- ORLAM’s Group, Department of Radiation Oncology, Mâcon, Villeurbanne, Lyon, France
| | - Isabelle Pouchard
- ORLAM’s Group, Department of Radiation Oncology, Mâcon, Villeurbanne, Lyon, France
| | - Mustapha Khodri
- ORLAM’s Group, Department of Radiation Oncology, Mâcon, Villeurbanne, Lyon, France
| | - Nicolas Barbet
- ORLAM’s Group, Department of Radiation Oncology, Mâcon, Villeurbanne, Lyon, France
| |
Collapse
|
13
|
Fu M, Cui Y, Qiu W, Cui Z, Zhang Y, Wang D, Yan S, Zhao Z, Wang Y, Zhu J. In Silico Studies of the Impact of Rotational Errors on Translation Shifts and Dose Distribution in Image-Guided Radiotherapy. Technol Cancer Res Treat 2023; 22:15330338231168763. [PMID: 37050884 PMCID: PMC10102941 DOI: 10.1177/15330338231168763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023] Open
Abstract
Objective: To compare the 6-dimensional errors of different immobilization devices and body regions based on 3-dimensional cone beam computed tomography for image-guided radiotherapy and to further quantitatively evaluate the impact of rotational corrections on translational shifts and dose distribution based on anthropomorphic phantoms. Materials and Methods: Two hundred ninety patients with cone beam computed tomographies from 3835 fractions were retrospectively analyzed for brain, head & neck, chest, abdomen, pelvis, and breast cases. A phantom experiment was conducted to investigate the impact of rotational errors on translational shifts using cone beam computed tomography and the registration system. For the dosimetry study, pitch rotations were simulated by adjusting the breast bracket by ±2.5°. Roll and yaw rotations were simulated by rotating the gantry and couch in the planning system by ±3.0°, respectively. The original plan for the breast region was designed in the computed tomography image space without rotation. With the same planning parameters, the original plan was transplanted into the image space with different rotations for dose recalculation. The effect of these errors on the breast target and organs at risk was assessed by dose-volume histograms. Results: Most of the mean rotational errors in the breast region were >1°. A single uncorrected yaw of 3° caused a change of 2.9 mm in longitudinal translation. A phantom study for the breast region demonstrated that when the pitch rotations were -2.5° and 2.5° and roll and yaw were both 3°, the reductions in the planning target volumes-V50 Gy were 20.07% and 29.58% of the original values, respectively. When the pitch rotation was +2.5°, the left lung V5 Gy and heart Dmean were 7.49% and 165.76 Gy larger, respectively, than the original values. Conclusions: Uncorrected rotations may cause changes in the values and directions of translational shifts. Rotational corrections may improve the patient setup and dose distribution accuracy.
Collapse
Affiliation(s)
- Min Fu
- Department of Radiation Oncology Physics and Technology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, People's Republic of China
| | - Yanhua Cui
- Department of Radiation Oncology Physics and Technology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, People's Republic of China
| | - Wenlong Qiu
- Department of Radiation Oncology Physics and Technology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, People's Republic of China
| | - Zhen Cui
- Department of Radiation Oncology Physics and Technology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, People's Republic of China
| | - Yan Zhang
- Department of Radiation Oncology Physics and Technology, Jiangsu Cancer Hospital, Jiangsu Institute of Cancer Research and Nanjing Medical University Affiliated Cancer Hospital, Nanjing, People's Republic of China
| | - Dandan Wang
- Department of Radiation Oncology Physics and Technology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, People's Republic of China
| | - Shaojie Yan
- Department of Radiation Oncology Physics and Technology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, People's Republic of China
| | - Zengjing Zhao
- Department of Radiation Oncology Physics and Technology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, People's Republic of China
| | - Yungang Wang
- Department of Radiation Oncology Physics and Technology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, People's Republic of China
| | - Jian Zhu
- Department of Radiation Oncology Physics and Technology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, People's Republic of China
| |
Collapse
|
14
|
Vasina EN, Kong N, Greer P, Baeza Ortega J, Kron T, Ludbrook JJ, Thwaites D, Lehmann J. First clinical experience with real-time portal imaging-based breath-hold monitoring in tangential breast radiotherapy. Phys Imaging Radiat Oncol 2022; 24:1-6. [PMID: 36092771 PMCID: PMC9450128 DOI: 10.1016/j.phro.2022.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 08/09/2022] [Accepted: 08/09/2022] [Indexed: 11/28/2022] Open
Abstract
Background and purpose Real-time treatment monitoring with the electronic portal imaging device (EPID) can conceptually provide a more accurate assessment of the quality of deep inspiration breath-hold (DIBH) and patient movement during tangential breast radiotherapy (RT). A system was developed to measure two geometrical parameters, the lung depth (LD) and the irradiated width (named here skin distance, SD), along three user-selected lines in MV EPID images of breast tangents. The purpose of this study was to test the system during tangential breast RT with DIBH. Materials and methods Measurements of LDs and SDs were carried out in real time. DIBH was guided with a commercial system using a marker block. Results from 17 patients were assessed. Mean midline LDs, <mLDs>, per tangent were compared to the planned mLDs; differences between the largest and smallest observed <mLDs> (<mSDs>) per tangent were calculated. Results For 56% (162/288) of the tangents tested, <mLDs> were outside the tolerance window. All but one patient had at least one fraction showing this behaviour. The largest difference found between an <mLD> and its planned mLD was −16.9 mm. The accuracy of patient positioning and the quality of marker-block-based DIBH guidance contributed to the differences. Fractions with patient position verification using a single EPID image taken before treatment showed a lower rate (34%), suggesting reassessment of setup procedures. Conclusions Real-time treatment monitoring of the internal anatomy during DIBH delivery of tangential breast RT is feasible and useful. The new system requires no additional radiation for the patient.
Collapse
Affiliation(s)
- Elena N. Vasina
- School of Information and Physical Sciences, University of Newcastle, Newcastle, Australia
- Corresponding author at: School of Information and Physical Sciences, University of Newcastle, University Drive, Callaghan, NSW 2308, Australia.
| | - Natalie Kong
- Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, Australia
| | - Peter Greer
- School of Information and Physical Sciences, University of Newcastle, Newcastle, Australia
- Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, Australia
| | - Jose Baeza Ortega
- School of Information and Physical Sciences, University of Newcastle, Newcastle, Australia
| | - Tomas Kron
- Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - Joanna J. Ludbrook
- Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, Australia
| | - David Thwaites
- Institute of Medical Physics, School of Physics, University of Sydney, Sydney, Australia
| | - Joerg Lehmann
- School of Information and Physical Sciences, University of Newcastle, Newcastle, Australia
- Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, Australia
- Institute of Medical Physics, School of Physics, University of Sydney, Sydney, Australia
| |
Collapse
|