Application of Optical Laser 3D Surface imaging system (Sentinel) in breast cancer radiotherapy

Mengjiao Liu,Wenming Yin,Xiaobo Wei,Kou Wang,Wendong Gu,Changhai Cheng,Jie Chen,Yun Ding

doi:10.1038/s41598-020-64496-1

Mengjiao Liu, Wenming Yin + Show 6 more

Open Access

https://doi.org/10.1038/s41598-020-64496-1

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Abstract

It has been clearly confirmed that radiation therapy (RT) after breast conserving surgery (BCS) is an effective treatment modality comparable to mastectomy for early breast cancer. The purpose of this study was to further evaluate the accuracy of 3D surface imaging system (Sentinel) for breast cancer patients received BCS. The optical surface scans and CBCT scans were acquired before and immediately after couch movement correction. The deviation of the CBCT scans from the reference planning CT was considered an estimate for the residual errors for patient setup correction. The planning target volume (PTV) margins for treatment sessions was calculated according to the setup errors. We obtained a total of 245 sets of data collected from 49 breast cancer patients. Compared with Sentinel setup errors, the residual setup errors as determined by the CBCT scans after couch movement correction were reduced in the six directions. The PTV margins derived from the CBCT residual errors were all less than 5 mm in X, Y, and Z directions. Our results suggested that Optical surface imaging can be applied in positioning for breast cancer patient accurately without unnecessary imaging dose.

Highlights

Breast cancer is the most common cancer with the highest morbidity in females worldwide, with more than 1.2 million cases diagnosed every year, accounting for 10–12% of the global female population and killing an average of 500,000 people every year
The Σ and δ of residual errors based on the CBCT scanned after the couch movement according to SE were shown in Table 2, these errors were comparable between the two alignment methods with the differences in six directions by 0.97 mm and 0.80 mm, 0.72 mm and 0.60 mm, 1.03 mm and 0.38 mm, 0.1°and 0.2°, 0.4°and 0.1°, 0.3°and 0.2°, respectively
The results show that the AlignRT system may be affected by respiratory movements, its translational error is less than 0.5 mm compared with EPID, so it is considered that the AlignRT system can partially replace EPID in the auxiliary placement of three-dimensional conformal radiotherapy for breast cancer

Summary

Introduction

Breast cancer is the most common cancer with the highest morbidity in females worldwide, with more than 1.2 million cases diagnosed every year, accounting for 10–12% of the global female population and killing an average of 500,000 people every year. For 3D conformal and intensity modulated radiation therapy techniques (IMRT) promise the radiation dose homogeneity within the planning target volume, at the same time reduce the radiation dose delivered to the contralateral breast, which may reduce toxicity and improve local control[3]. Image-guided radiation therapy (IGRT) can improve the accuracy of positioning by reducing the distance between the clinical target volume (CTV) and the planned target volume (PTV)[4]. This technique uses ionizing radiation which increase the extra imaging dose to patients[5]. We have collected 27 cases of breast cancer patients who underwent radiation therapy after breast-conserving surgery, and analyzed the setup accuracy of optical surface imaging by the Sentinel system and its correlation with CBCT. We collected 49 breast cancer patients with the same conditions to further study the accuracy of 3D surface imaging system (Sentinel)

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