Clinical trials

This open-label, randomized Phase II trial evaluates whether sequential iodine-125 seed implantation followed by cryoablation improves local tumor control versus single-modality local therapy (125I seeds alone or cryoablation alone) in unresectable solid tumors. The study is based on a complementary treatment rationale: cryoablation provides rapid cytoreduction of the dominant tumor component, while 125I seed brachytherapy delivers sustained low-dose-rate irradiation that may better suppress residual viable tumor at the periphery and microscopic extension zones. The trial is designed to determine whether this spatial and temporal complementarity translates into superior local disease control without unacceptable toxicity. Participants will be randomized in parallel to one of three arms: (1) sequential 125I seed implantation followed by cryoablation within a protocol-defined interval, (2) 125I seed implantation alone, or (3) cryoablation alone. Treatment assignment is open label; imaging-based efficacy endpoints will be assessed using a standard blinded assessment process (blinded evaluators), according to protocol-defined criteria. The primary endpoint is local control rate (LCR) of prespecified target lesions and progression-free survival (PFS). Key secondary endpoints are local progression-free survival (LPFS), overall survival (OS), early pain response, technical success, target-lesion re-intervention rate, and safety (including grade ≥3 treatment-emergent adverse events, CTCAE v5.0). Exploratory analyses include dosimetry-outcome associations, imaging/radiomics biomarkers, and peripheral blood biomarker dynamics.

This open-label, randomized Phase II trial evaluates whether a strategy-based, multimodal local treatment approach improves local control compared with single-modality local therapy in patients with high-burden metastatic disease characterized by multiple metastases and at least one bulky lesion. In the experimental arm, prespecified target lesions are prospectively allocated to either iodine-125 (125I) seed implantation or cryoablation using protocol-defined anatomic and technical suitability criteria, and at least one bulky index lesion is treated using a tumor-zoned approach (e.g., core debulking with cryoablation and peripheral/high-risk margin control with 125I seeds) under predefined organ-at-risk constraints. The control arm treats all prespecified target lesions with a single local modality (either 125I seed implantation alone or cryoablation alone), with standardized supportive care and follow-up. The primary objective is to determine whether the "lesion allocation plus tumor zoning" strategy can improve local control of treated target lesions with acceptable safety. Imaging-based efficacy endpoints are evaluated using protocol-defined criteria with standardized blinded independent imaging review. Key secondary endpoints include local progression-free survival of the bulky index lesion, overall response rate (RECIST), progression-free survival, time to systemic progression (including new lesions), overall survival, tumor-burden reduction metrics, technical success, and re-intervention rates. Safety is assessed throughout the study using CTCAE v5.0, including monitoring for procedure-related and radiation-related complications. Exploratory analyses assess dosimetry-outcome relationships, zonal response patterns within bulky lesions, imaging/radiomics biomarkers, and peripheral blood biomarker dynamics.

Most patients with metastatic cancer eventually develop resistance to systemic therapy. A subset of patients experience oligoprogression, characterized by progression at a limited number of lesions while other disease sites remain controlled by ongoing systemic therapy. This randomized phase 2 trial evaluates whether image-guided 125I seed implantation targeting all oligoprogressive extracranial lesions, combined with standard-of-care systemic therapy, improves progression-free survival compared with standard-of-care systemic therapy alone in patients with metastatic NSCLC or CRC.

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.

Patients with more than five and up to ten metastatic lesions often have limited tolerance for surgery, radiotherapy, or thermal ablation because of cumulative treatment burden or expected toxicity. In this setting, systemic therapy alone frequently remains the primary treatment option. This prospective, open-label, randomized phase 2 study evaluates whether image-guided iodine-125 (125I) seed implantation, when added to standard-of-care systemic therapy, can improve disease control compared with standard systemic therapy alone in patients with multiple metastatic lesions. Clinical outcomes including progression-free survival, overall survival, safety, and quality of life will be prospectively assessed.

This prospective randomized trial evaluates the efficacy and safety of combining 125I seed interstitial brachytherapy with immune checkpoint inhibitor therapy in patients with primary, recurrent, or metastatic malignant tumors. Immunotherapy has become an important systemic treatment option, yet many patients experience limited benefit due to low tumor immunogenicity, insufficient T-cell infiltration, and an immunosuppressive tumor microenvironment. 125I seed brachytherapy provides continuous low-dose-rate radiation to the tumor, promoting antigen release, enhancing dendritic cell activation, and potentially converting immunologically "cold" tumors into more responsive "hot" lesions. Integrating localized radiation with systemic immunotherapy may improve tumor response, prolong progression-free survival, and reduce recurrence. Patients will be randomized 1:1 to receive 125I seed implantation plus immunotherapy or immunotherapy alone. The primary endpoints are objective response rate (ORR) and progression-free survival (PFS). Secondary endpoints include failure-free survival (FFS), overall survival (OS), disease control rate (DCR), duration of response (DoR), local control, recurrence rate, adverse events, and quality of life. Exploratory analyses will assess radiomics features, subgroup responses, and different patterns of recurrence. This study aims to determine whether adding 125I seed brachytherapy enhances the clinical benefits of immunotherapy across diverse malignant tumors.

This prospective, open-label randomized trial evaluates a dual-simulation planning strategy that combines standard brachytherapy TPS with patient-specific biomechanical modeling for radioactive seed implantation in bone metastases. The approach aims to improve dose coverage while accounting for fracture risk, needle path stability, and seed migration. Eligible patients with painful and/or progressive bone metastases are randomized to dual-simulation planning versus conventional TPS. All undergo image-guided implantation with post-implant dosimetric verification and standardized follow-up. The primary endpoint is 3-month pain response (BPI/VAS, adjusted for analgesic use). Secondary endpoints include dosimetry (D90, V100, CI, HI), local control/progression, seed migration, skeletal-related events and fractures, SINS and functional status, quality of life, procedure-related complications (CTCAE v5.0), and procedure metrics. We hypothesize the dual-simulation strategy will enhance dosimetric quality and reduce biomechanics-related complications, improving pain and function.