A retrospective comparison of setup accuracy from CBCT and SGRT data in breast cancer patients

Andrea Lastrucci; Eva Serventi; Giulio Francolini; Luisa Marciello; Luca Fedeli; Francesco Meucci; Salvino Marzano; Marco Esposito; Renzo Ricci

doi:10.1016/j.jmir.2023.10.005

A retrospective comparison of setup accuracy from CBCT and SGRT data in breast cancer patients

J Med Imaging Radiat Sci. 2024 Mar;55(1):29-36. doi: 10.1016/j.jmir.2023.10.005. Epub 2023 Nov 27.

Authors

Andrea Lastrucci¹, Eva Serventi², Giulio Francolini³, Luisa Marciello⁴, Luca Fedeli⁵, Francesco Meucci⁵, Salvino Marzano⁴, Marco Esposito⁶, Renzo Ricci⁷

Affiliations

¹ Radiation Oncology Unit, Santo Stefano Hospital, Department of Allied Health Professions, Azienda USL Toscana Centro, Prato 59100, Italy. Electronic address: andrea.lastrucci@unifi.it.
² Radiation Oncology Unit, Santo Stefano Hospital, Department of Allied Health Professions, Azienda USL Toscana Centro, Prato 59100, Italy.
³ Radiation Oncology Unit, Azienda Ospedaliero-Universitaria Careggi, 50134 Florence, Italy.
⁴ Radiation Oncology Unit, Santo Stefano Hospital, Department of Oncology, Azienda USL Toscana Centro, Prato 59100, Italy.
⁵ Medical Physics Unit, Santo Stefano Hospital, Azienda USL Toscana Centro, Prato-Pistoia 59100, Italy.
⁶ Medical Physics, The Abdus Salam International Centre for Theoretical Physics, Trieste 34151, Italy.
⁷ Department of Allied Health Professions, Azienda Ospedaliero-Universitaria Careggi, 50134 Florence, Italy.

PMID: 38016852
DOI: 10.1016/j.jmir.2023.10.005

Abstract

Introduction: Both cone-beam computed tomography (CBCT) and surface-guided radiotherapy (SGRT) are used for breast patient positioning verification before treatment delivery. SGRT may reduce treatment time and imaging dose by potentially reduce the number of CBCT needed. The aim of this study was to compare the displacements resulting in positioning from the Image Guided Radiation Therapy (IGRT) 3D and SGRT methods and to design a clinical workflow for SGRT implementation in breast radiotherapy to establish an imaging strategy based on the data obtained.

Methods: For this study 128 breast cancer patients treated with 42.5 Gy in 16 fractions using 3D conformal radiotherapy with free breathing technique were enroled. A total of 366 CBCT images were evaluated for patient setup verification and compared with SGRT. Image registrations between planning CT images and CBCT images were performed in mutual agreement and in online mode by three health professionals. Student's paired t-test was used to compare the absolute difference in vector shift, measured in mm, for each orthogonal axis (x, y, z) between SGRT and CBCT methods. The multidisciplinary team evaluated a review of the original clinical workflow for SGRT implementation and data about patients treated with the updated workflow were reported.

Results: Comparison of the shifts obtained with IGRT and SGRT for each orthogonal axis (for the x-axes the average displacement was 0.9 ± 0.7 mm, y = 1.1 ± 0.8 mm and z = 1.0 ± 0.7 mm) revealed no significant statistical differences (p > 0.05). Using the updated workflow the difference between SGRT and IGRT displacements was <3 mm in 91.4 % of patients with a reduction in total treatment time of approximately 20 %, due to the reduce frequency of the CBCT images acquisition and matching.

Conclusions: This study has shown that IGRT and SGRT agree in positioning patients with breast cancer within a millimetre tolerance. SGRT can be used for patient positioning, with the advantages of reducing radiation exposure and shorter overall treatment time.

Keywords: Breast cancer; IGRT; Radiotherapy; SGRT.

MeSH terms

Breast Neoplasms* / diagnostic imaging
Breast Neoplasms* / radiotherapy
Female
Humans
Image Processing, Computer-Assisted / methods
Radiotherapy Planning, Computer-Assisted / methods
Radiotherapy, Intensity-Modulated* / methods
Retrospective Studies
Spiral Cone-Beam Computed Tomography*