This prospective, open-label Phase I/II trial evaluates a PET/CT-guided planning strategy for radioactive seed implantation therapy in malignant solid tumors. The approach integrates metabolic information from PET/CT into brachytherapy planning to improve the accuracy of biological target volume delineation, enhance dose coverage, and support biologically informed dose delivery. Eligible participants are assigned to one of three arms: conventional CT-guided implantation, PET/CT-guided standard-dose implantation, or PET/CT-guided biologically optimized implantation. All participants undergo image-guided treatment followed by post-implant dosimetric verification and standardized clinical follow-up.
Primary endpoints include technical success rate, dosimetric superiority, and 6-month local control. Secondary endpoints include dosimetric indices (D90, V100, conformity index, homogeneity index), pain relief, quality of life (EORTC QLQ-C30), treatment-related adverse events (CTCAE v5.0), progression-free survival (PFS), failure-free survival (FFS), and overall survival (OS). Exploratory analyses will evaluate associations between baseline PET metabolic parameters (SUVmax, metabolic tumor volume) and clinical outcomes, assess the feasibility of SUV-guided dose painting, and compare the performance of tumor-specific tracers (such as PSMA and FAPI) with FDG for target delineation and treatment response prediction.
The central hypothesis is that PET/CT-guided planning-particularly when incorporating biological dose optimization-will achieve superior dosimetric performance and improved local control and survival outcomes compared with conventional CT-guided implantation.
Age ≥ 18 years.
Pathologically or clinically confirmed malignant tumor (solid tumor, lymphoma, or leukemia with a localized lesion suitable for radioactive seed implantation).
Tumor site accessible for image-guided implantation, with a target lesion visible on CT or PET/CT.
Life expectancy of at least 6 months.
Pregnant or breastfeeding women.
Uncontrolled infection or active systemic inflammatory disease.
Severe cardiopulmonary dysfunction that contraindicates interventional procedures (e.g., heart failure, severe COPD).
Coagulation disorders (INR > 1.5 or platelet count < 50 × 10⁹/L).
Li Min
Lead sponsor
Jinan Military General Hospital
Sponsor institution