In an operating room in Beijing, surgeons now have a new ally: a real-time imaging system that can see what the human eye cannot—the precise boundary between cancerous bone tumor and healthy tissue. Researchers at Peking University Cancer Hospital have developed an integrated PET imaging platform using B7-H3-targeted radiotracers that enables surgeons to map tumor margins with unprecedented accuracy during osteosarcoma resection, a breakthrough that could reshape how this aggressive childhood cancer is treated.
Osteosarcoma ranks among the most lethal primary malignant bone tumors in children and adolescents, and the stakes of surgery are unforgiving: if even a microscopic fragment of cancer remains at the surgical margin, the risk of local recurrence climbs sharply and long-term survival suffers. Current surgical practice relies on surgeon experience and imaging obtained before the operation—tools that often fall short when the actual anatomy is exposed. "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," said Bo Mei, Ph.D., of Peking University Cancer Hospital and Institute.
The platform's breakthrough begins with a fundamental observation: over 80 percent of osteosarcoma cases show high expression of the protein B7-H3. Researchers synthesized the first B7-H3-targeted radiotracer, 68Ga-B7H3-BCH, and demonstrated in preclinical studies that its diagnostic performance significantly outpaced clinically used tracers. They then built a dual-modality integrated imaging pipeline combining two complementary probes—the 68Ga-B7H3-BCH radiotracer for whole-body staging and a near-infrared B7H3 fluorescent probe for real-time visualization during surgery itself.
The workflow moves seamlessly through three phases. First, the PET/CT radiotracer non-invasively and quantitatively maps B7-H3 expression throughout the body, enabling precise staging and surgical planning before the patient enters the operating room. Second, the near-infrared fluorescent probe activates during surgery, providing surgeons with high-resolution visualization of tumor margins in real time, allowing them to see exactly where to cut and what to preserve. Third, a rapid pathological margin verification technique completes the assessment within 30 minutes, offering immediate confirmation that resection was complete. Early feasibility evidence has already emerged from an ongoing PET imaging study in patients, demonstrating the platform's potential.
The implications extend far beyond the operating room. "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," Mei said. This shift matters: preserving limb function while ensuring complete tumor removal is the eternal tension in osteosarcoma surgery, and precision imaging offers a way to thread that needle.
The platform remains investigational, and further prospective clinical validation, safety assessment, and regulatory review lie ahead before it reaches clinical use. Yet the early evidence presented at the Society of Nuclear Medicine and Molecular Imaging 2026 Annual Meeting signals that surgeons may soon operate with a level of real-time certainty that was previously impossible—one that could reduce recurrence, save limbs, and ultimately save lives.