Surface guided radiotherapy (SGRT) improves breast cancer patient setup accuracy

Kügele, M.; Mannerberg, Annika; Bekke, Susanne Nørring; Alkner, Sara; Berg, L.; Mahmood, Faisal; Thornberg, Charlotte; Edvardsson, A.; Bäck, Sven; Behrens, C.F.; Ceberg, Sofie

doi:10.1002/acm2.12700

Cited by 81 publications

(106 citation statements)

References 16 publications

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“…There is a broad agreement on the supremacy of SGRT over 3-point laser-based patient setup, when the surface serves as a surrogate for the target positioning, i.e. breast and other skin-near targets [13,16,[21][22][23][24][25][26][27][28][29][30]. For deeper situated targets, surface imaging should be used with caution [13,22,31,32].…”

Section: Clinical Applicationsmentioning

confidence: 99%

“…In this context, it has been shown that surface-guided correction of the arm posture also improved the breast position [13,16,27,30]. Nevertheless, some factors can affect the accuracy in surface-guided patient setup, such as patient motion [35], surface shadowing [16], selection of the region-of interest (ROI) [14], absence of anatomical gradients in the patient (e.g. very flat surfaces) and anatomical changes throughout the treatment [21,28,36].…”

Section: Breast Positioningmentioning

confidence: 99%

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Recent advances in Surface Guided Radiation Therapy

et al. 2020

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The growing acceptance and recognition of Surface Guided Radiation Therapy (SGRT) as a promising imaging technique has supported its recent spread in a large number of radiation oncology facilities. Although this technology is not new, many aspects of it have only recently been exploited. This review focuses on the latest SGRT developments, both in the field of general clinical applications and special techniques. SGRT has a wide range of applications, including patient positioning with real-time feedback, patient monitoring throughout the treatment fraction, and motion management (as beam-gating in free-breathing or deep-inspiration breath-hold). Special radiotherapy modalities such as accelerated partial breast irradiation, particle radiotherapy, and pediatrics are the most recent SGRT developments. The fact that SGRT is nowadays used at various body sites has resulted in the need to adapt SGRT workflows to each body site. Current SGRT applications range from traditional breast irradiation, to thoracic, abdominal, or pelvic tumor sites, and include intracranial localizations. Following the latest SGRT applications and their specifications/requirements, a stricter quality assurance program needs to be ensured. Recent publications highlight the need to adapt quality assurance to the radiotherapy equipment type, SGRT technology, anatomic treatment sites, and clinical workflows, which results in a complex and extensive set of tests. Moreover, this review gives an outlook on the leading research trends. In particular, the potential to use deformable surfaces as motion surrogates, to use SGRT to detect anatomical variations along the treatment course, and to help in the establishment of personalized patient treatment (optimized margins and motion management strategies) are increasingly important research topics. SGRT is also emerging in the field of patient safety and integrates measures to reduce common radiotherapeutic risk events (e.g. facial and treatment accessories recognition). This review covers the latest clinical practices of SGRT and provides an outlook on potential applications of this imaging technique. It is intended to provide guidance for new users during the implementation, while triggering experienced users to further explore SGRT applications.

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Section: Clinical Applicationsmentioning

confidence: 99%

Section: Breast Positioningmentioning

confidence: 99%

Recent advances in Surface Guided Radiation Therapy

et al. 2020

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“…Currently, no guidelines exist in terms of rotational tolerances for SGRT and no recommendations are provided by the vendors. Default settings are in the range 3–5° and a value of 3° is probably more common and used in a recent study by Kügele et al . Based on our findings, clinically we now strictly enforce a 2° rotational tolerance before we start treatment to minimize vertical setup errors as a result of the rotations.…”

Section: Discussionmentioning

confidence: 87%

Characterizing a deformable registration algorithm for surface‐guided breast radiotherapy

et al. 2019

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Purpose Surface‐guided radiation therapy (SGRT) is a nonionizing imaging approach for patient setup guidance, intra‐fraction monitoring, and automated breath‐hold gating of radiation treatments. SGRT employs the premise that the external patient surface correlates to the internal anatomy, to infer the treatment isocenter position at time of treatment delivery. Deformations and posture variations are known to impact the correlation between external and internal anatomy. However, the degree, magnitude, and algorithm dependence of this impact are not intuitive and currently no methods exist to assess this relationship. The primary aim of this work was to develop a framework to investigate and understand how a commercial optical surface imaging system (C‐RAD, Uppsala, Sweden), which uses a nonrigid registration algorithm, handles rotations and surface deformations. Methods A workflow consisting of a female torso phantom and software‐introduced transformations to the corresponding digital reference surface was developed. To benchmark and validate the approach, known rigid translations and rotations were first applied. Relevant breast radiotherapy deformations related to breast size, hunching/arching back, distended/deflated abdomen, and an irregular surface to mimic a cover sheet over the lower part of the torso were investigated. The difference between rigid and deformed surfaces was evaluated as a function of isocenter location. Results For all introduced rigid body transformations, C‐RAD computed isocenter shifts were determined within 1 mm and 1˚. Additional translational shifts to correct for rotations as a function of isocenter location were determined with the same accuracy. For yaw setup errors, the difference in shift corrections between a plan with an isocenter placed in the center of the breast (BrstIso) and one located 12 cm superiorly (SCFIso) was 2.3 mm/1˚ in lateral direction. Pitch setup errors resulted in a difference of 2.1 mm/1˚ in vertical direction. For some of the deformation scenarios, much larger differences up to 16 mm and 7˚ in the calculated shifts between BrstIso and SCFIso were observed that could lead to large unintended gaps or overlap between adjacent matched fields if uncorrected. Conclusions The methodology developed lends itself well for quality assurance (QA) of SGRT systems. The deformable C‐RAD algorithm determined accurate shifts for rigid transformations, and this was independent of isocenter location. For surface deformations, the position of the isocenter had considerable impact on the registration result. It is recommended to avoid off‐axis isocenters during treatment planning to optimally utilize the capabilities of the deformable image registration algorithm, especially when multiple isocenters are used with fields that share a field edge.

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“…9 The advantage of using surface scanning is that the information from the surface can improve the patient setup compared to in-room lasers. [10][11][12] Also, a surface scan takes seconds, in comparison to minutes for MVCT. Thus, surface scanning has the potential to increase the accuracy, without substantially adding time for setup compared to setup with in-room lasers.…”

Section: Introductionmentioning

confidence: 99%

Surface‐guided tomotherapy improves positioning and reduces treatment time: A retrospective analysis of 16 835 treatment fractions

Haraldsson

Ceberg

et al. 2020

J Applied Clin Med Phys

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In this study, we have quantified the setup deviation and time gain when using fast surface scanning for daily setup/positioning with weekly megavoltage computed tomography (MVCT) and compared it to daily MVCT. Methods: A total of 16 835 treatment fractions were analyzed, treated, and positioned using our TomoTherapy HD (Accuray Inc., Madison, USA) installed with a Sentinel optical surface scanning system (C-RAD Positioning AB, Uppsala, Sweden). Patients were positioned using in-room lasers, surface scanning and MVCT for the first three fractions. For the remaining fractions, in-room laser was used for setup followed by daily surface scanning with MVCT once weekly. The three-dimensional (3D) setup correction for surface scanning was evaluated from the registration between MVCT and the planning CT. The setup correction vector for the in-room lasers was assessed from the surface scanning and the MVCT to planning CT registration. The imaging time was evaluated as the time from imaging start to beam-on. Results: We analyzed 894 TomoTherapy treatment plans from 2012 to 2018. Of all the treatment fractions performed with surface scanning, 90 % of the residual errors were within 2.3 mm for CNS (N = 284), 2.9 mm for H&N (N = 254), 8.7 mm for thorax (N = 144) and 10.9 for abdomen (N = 134) patients. The difference in residual error between surface scanning and positioning with in-room lasers was significant (P < 0.005) for all sites. The imaging time was assessed as total imaging time per treatment plan, modality, and treatment site and found that surface scanning significantly reduced patient on-couch time compared to MVCT for all treatment sites (P < 0.005). Conclusions: The results indicate that daily surface scanning with weekly MVCT can be used with the current target margins for H&N, CNS, and thorax, with reduced imaging time.

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Surface guided radiotherapy (SGRT) improves breast cancer patient setup accuracy

Cited by 81 publications

References 16 publications

Recent advances in Surface Guided Radiation Therapy

Recent advances in Surface Guided Radiation Therapy

Characterizing a deformable registration algorithm for surface‐guided breast radiotherapy

Surface‐guided tomotherapy improves positioning and reduces treatment time: A retrospective analysis of 16 835 treatment fractions

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