A new end-to-end PET imaging approach for osteosarcoma can rapidly and reliably distinguish tumor tissue from normal tissue and accurately assess surgical margins in real time. The novel platform, presented at the Society of Nuclear Medicine and Molecular Imaging 2026 Annual Meeting, has the potential to fundamentally reshape surgical practice for osteosarcoma by enabling precise tumor resection, significantly reducing the risk of local recurrence, and preserving maximum limb function.
Osteosarcoma is among the most aggressive primary malignant bone tumors in children and adolescents. The current standard of care consists of chemotherapy combined with radical surgical resection. Achieving complete tumor removal is the core objective of surgical treatment, as positive margins increase the risk of local recurrence and adversely affect long-term survival.
Despite continuous advances in surgical techniques, orthopedic surgeons still face a major challenge: how to delineate tumor margins accurately during surgery so as to ensure complete tumor removal while maximizing preservation of limb function. The development of an innovative technology capable of rapidly and reliably distinguishing tumor tissue from normal tissue and accurately assessing surgical margins in real time has become an urgent clinical priority in osteosarcoma management."
Bo Mei, PhD, Peking University Cancer Hospital and Institute, Beijing, China
High expression of the protein B7‑H3 is observed in over 80 percent of osteosarcoma cases, making it an attractive target for both imaging and therapy. In the study, researchers developed and synthesized the first B7-H3-targeted radiotracer, 68Ga-B7H3-BCH. Preclinical studies were conducted to assess its ability to detect lesions in cell lines and in mouse models.
After determining that 68Ga-B7H3-BCH's diagnostic performance was significantly superior to that of clinically used tracers, researchers then established a B7-H3-targeted dual-modality integrated imaging platform. The platform combined two complementary imaging probes -- 68Ga-B7H3-BCH and a near-infrared B7H3 fluorescent probe -- to form an imaging pipeline for preoperative staging, real-time resection navigation, and postoperative margin verification. PET/CT mouse studies were conducted to determine tracer uptake around margins and near-infrared fluorescence imaging was utilized during surgical resection to identify and validate margins. Histological comparisons were used to assess the platform s accuracy.
68Ga-B7H3-BCH PET/CT non-invasively and quantitatively mapped B7-H3 expression throughout the body, enabling precise staging of osteosarcoma. The near-infrared B7H3 fluorescent probe enabled real-time, high-resolution visualization of tumor margins, and a rapid pathological margin verification technique integrated into the platform completed margin assessment within 30 minutes.
"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," said Mei.
While the platform remains investigational, an ongoing PET imaging study has provided early feasibility evidence in patients. Further prospective clinical validation, safety assessment, regulatory review, and optimization of clinical workflows are needed before this platform can be used in patients with osteosarcoma.
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