Main Session
Sep
27
PQA 02 - Pediatric Cancer, Sarcoma and Cutaneous Tumors, Medical Education & Professional Development, and Health Services Research
2396 - Clinical Application and Efficacy Observation of SGRT in Precision Radiotherapy for Extremity Malignant Tumors
Presenter(s)
Lin Yang, - Department of Radiotherapy, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi Province,
L. Yang; Department of Radiotherapy, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
Purpose/Objective(s):
Extremity malignant tumor radiotherapy is prone to set-up errors and limb movement-related dose deviation, with traditional image-guided techniques having limitations of cumulative radiation and delayed monitoring. This study explored the clinical value of Surface-Guided Radiation Therapy (SGRT) in precision radiotherapy for extremity malignant tumors, hypothesizing it could improve radiotherapy accuracy and reduce normal tissue damage.Materials/Methods:
68 patients with pathologically confirmed extremity malignant tumors who received IMRT from Jan to Dec 2025 were enrolled (43 males, 25 females; median age 46 years),all of whom were fixed with vacuum bags. SGRT was used for full-course position guidance and real-time movement monitoring (threshold: 1mm). Observation indicators included set-up errors (LR, SI, AP directions), acute adverse reactions (CTCAE v5.0), treatment efficiency, target dose distribution (CI, HI), and normal tissue irradiation dose. SPSS 26.0 was used for statistical analysis (P<0.05 significant).Results:
All 68 patients completed full-course IMRT without withdrawal. After SGRT, inter-fraction set-up errors were (0.72±0.21)mm (LR), (0.68±0.19)mm (SI), (0.75±0.23)mm (AP), significantly lower than before [(2.35±0.58)mm, (2.21±0.52)mm, (2.42±0.61)mm; all P < 0.05]. Intra-fraction errors were =1mm, and set-up qualification rate increased from 78.6% to 97.6% (P < 0.05). SGRT captured 28 cases of slight limb movement and intervened timely to avoid dose deviation. Acute skin reaction incidence was 38.1% (26/68; 24 Grade ?-?, 2 Grade ?, no Grade ?), limb edema 9.5% (6/68), neurotoxicity 7.1% (5/68)—all lower than traditional radiotherapy (P < 0.05). Normal tissue irradiation dose was lower than planned (P < 0.05). Single set-up time shortened by 45.6% (P < 0.05); target CI=0.85±0.06, HI=0.12±0.03 (meeting precision standards), dose deviation = 2%. CBCT use decreased by 60%, reducing additional radiation.
Conclusion:
SGRT in precision IMRT for extremity malignant tumors effectively corrects set-up errors and monitors limb movement in real time. It ensures target dose accuracy, reduces normal tissue irradiation and adverse reactions, optimizes workflow, improves efficiency, and decreases additional radiation; vacuum bag fixation enhances positional stability. SGRT is a safe, effective positional guidance technique with high clinical value, supporting better therapeutic effect and patient quality of life.