Publications by authors named "Liwan Shi"
Article Synopsis
- The study investigates the correlation between cone-beam CT (CBCT) and positioning CT (pCT) measurements of tumor characteristics in locally advanced rectal cancer and explores the possibility of using CBCT as a substitute for pCT.
- It involved 103 patients undergoing treatment, with their imaging data divided into training and validation sets, using a deep learning model to analyze tumor features.
- Results show that while the modified model performed better with pCT images, several extracted features from both imaging methods are highly correlated, highlighting the potential of CBCT in understanding cancer staging and prognosis.
Background: Volumetric modulated arc therapy (VMAT) with varied bolus thicknesses has been employed in postmastectomy radiotherapy (PMRT) of breast cancer to improve superficial target coverage. However, impact of bolus thickness on plan robustness remains unclear.
Methods: The study enrolled ten patients with left-sided breast cancer who received radiotherapy using VMAT with 5 mm and 10 mm bolus (VMAT-5B and VMAT-10B).
Purpose: The aim of this work was to demonstrate a practical and effective method to improve the performance of RapidPlan (RP) model.
Methods: 203 consecutive clinical VMAT plans (P) for cervical and endometrial cancer were used to train an RP model (M). The plans were then reoptimized by M to generate 203 new plans (P).
Background: Before generating radiotherapy plans for breast cancer patients, the choice of plan techniques (three-dimensional conformal radiation therapy (3D-CRT) and volumetric modulated arc therapy (VMAT)) should be made. This study investigated the performance of two geometric indices in aiding the choice of 3D-CRT and VMAT plans in women undergoing left-sided whole breast radiotherapy.
Materials And Methods: 119 patients, previously treated with left-sided breast radiotherapy (61 3D-CRT treatments and 58 VMAT treatments) from a single institution, were retrospectively studied.
Purpose: For whole esophagus and T-shaped field radiotherapy using intensity modulated radiotherapy (IMRT) technique in advanced esophageal cancer, lower absorbed doses to lung and heart remains a challenge. The aim of this study was to investigate the dosimetric superiority in IMRT plans with jaw tracking technique for whole esophagus radiotherapy.
Methods And Materials: Thirty-two patients with esophageal cancer were subjected to IMRT treatment plans using Eclipse treatment planning system.
Article Synopsis
- The study investigates the effectiveness of flattening filter free (FFF) beams in volumetric modulated arc therapy (VMAT) for treating single brain metastases, comparing it to traditional flattened (FF) beams.
- Involving 68 patients, the research found that while both techniques had similar conformity and monitor units used, FFF beams outperformed FF beams in terms of dose homogeneity, dose gradients, and beam efficiency.
- FFF plans reduced treatment time by 42.8% and minimized brain irradiation by approximately 2% in low-dose areas, indicating a more efficient and safer approach to stereotactic radiosurgery for brain metastases.
Article Synopsis
- Conventional volumetric modulated arc therapy (C-VMAT) for breast cancer has limitations by exposing larger areas of normal tissue to low radiation doses after radical mastectomy.
- A study involving 20 patients tested three types of VMAT plans (C-VMAT, modified-VMAT, and modified-VMAT with flattening filter-free beams) alongside 3D conformal radiotherapy to assess the impact on dose distribution and efficiency.
- Results showed that while C-VMAT was better than 3DCRT in medium to high doses, the modified plans (M-VMAT and M-VMAT-F) reduced low-dose areas and provided better protection for surrounding organs, with M-VMAT-F slightly outperforming M
Flattening filter free (FFF) may affect outcome measures of radiotherapy. The objective of this study is to compare the dosimetric parameters in three types of radiotherapy plans, three-dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT), with or without the flattening filter (FF), developed for the treatment of metastatic brain tumors from non-small cell lung cancer (NSCLC). From July 2013 to October 2013, 3D-CRT, IMRT, and VMAT treatment plans were designed using 6 MV and 10 MV, with and without FF, for 10 patients with brain metastasis from NSCLC.
View Article and Find Full Text PDFPurpose: Flattening filter free (FFF) beams show the potential for a higher dose rate and lower peripheral dose. We investigated the planning study of FFF beams with their role for volumetric modulated arc therapy (VMAT) in squamous cell carcinoma of the scalp.
Methods And Materials: One patient with squamous cell carcinoma which had involvement of entire scalp was subjected to VMAT using TrueBeam linear accelerator.