BEIJING — Researchers at Peking University Cancer Hospital unveiled a new B7-H3-targeted PET imaging platform for osteosarcoma at the 2026 Society of Nuclear Medicine and Molecular Imaging Annual Meeting. The investigational platform combines a novel radiotracer and a fluorescent probe to support precise tumor detection and surgical guidance.
The platform centers on 68Ga-B7H3-BCH, the first B7-H3-targeted radiotracer, which researchers synthesized to exploit the high expression of the B7-H3 protein observed in over 80 percent of osteosarcoma cases. In preclinical studies, 68Ga-B7H3-BCH demonstrated superior diagnostic performance compared to clinically used tracers when tested in cell lines and mouse models.
Researchers integrated 68Ga-B7H3-BCH with a near-infrared B7H3 fluorescent probe to create a dual-modality system. This platform enables a full pipeline from preoperative staging through real-time surgical navigation to postoperative margin verification. 68Ga-B7H3-BCH PET/CT non-invasively and quantitatively mapped B7-H3 expression across the body, allowing precise disease staging, while the fluorescent probe provided real-time, high-resolution visualization of tumor margins during resection.
The system also incorporates a rapid pathological margin verification technique that completes assessment within 30 minutes. PET/CT mouse studies evaluated tracer uptake around surgical margins, and near-infrared fluorescence imaging was used intraoperatively to identify and confirm margins, with histological comparisons validating the platform’s accuracy. The approach can rapidly and reliably distinguish tumor tissue from normal tissue and accurately assess surgical margins in real time.
Osteosarcoma is among the most aggressive primary malignant bone tumors in children and adolescents. Current standard treatment involves chemotherapy combined with radical surgical resection, where complete tumor removal is critical—positive margins increase the risk of local recurrence and negatively impact long-term survival.
Bo Mei, PhD, of Peking University Cancer Hospital and Institute in Beijing, described the platform’s potential impact: "The development and clinical translation of this integrated platform will facilitate a paradigm shift in osteosarcoma care, from empirical 'surgery plus systemic chemotherapy' to individualized, precision, closed-loop diagnosis and treatment carrying major clinical and scientific significance." An ongoing PET imaging study has provided early feasibility evidence in patients, but the platform remains investigational. Further prospective clinical validation, safety assessment, regulatory review, and optimization of clinical workflows are required before it can be used in routine patient care.