Boron Neutron Capture Therapy – The "Fifth Cancer Therapy" Enters Clinical Trials in China

Often called the "fifth cancer therapy" after surgery, chemotherapy, radiation therapy, and immunotherapy, boron neutron capture therapy (BNCT) is a revolutionary treatment that selectively destroys cancer cells at the cellular level. In 2026, China's first domestically developed BNCT system entered clinical trials.

I. Introduction: A New Paradigm in Cancer Treatment

Boron neutron capture therapy (BNCT) is a targeted radiation therapy that delivers a lethal radiation dose specifically to cancer cells while sparing surrounding healthy tissue. It is often described as the "fifth cancer therapy" — a completely new modality distinct from surgery, chemotherapy, conventional radiation, and immunotherapy.

The concept of BNCT has been around for decades, but it has only recently become clinically feasible due to advances in accelerator-based neutron sources, boron-10 drug delivery, and treatment planning software. China has emerged as one of the global leaders in BNCT development, with the HyBorSys® system now entering clinical trials.

II. How BNCT Works: A "Biological Missile" at the Cellular Level

BNCT is a two-step therapy:

1. Boron-10 administration: The patient receives an infusion of a boron-10-containing drug that selectively accumulates in tumor cells. The boron-10 isotope has a high neutron capture cross-section — it is designed to "wait" for neutrons.
2. Neutron irradiation: The tumor site is irradiated with a beam of low-energy (epithermal) neutrons. When these neutrons encounter boron-10 within cancer cells, they trigger a nuclear reaction that releases high-energy alpha particles and lithium nuclei — both of which have a short range (approximately 5–9 microns, about the diameter of a single cell).

The key innovation of BNCT is its cellular-level precision: the destructive radiation is released only within cells that have accumulated boron-10, which are predominantly cancer cells. Healthy cells with minimal boron uptake are largely spared.

III. HyBorSys®: China's First Domestically Produced BNCT System

The HyBorSys® system, developed by Hua-Boron Neutron Capture Technology (华硼中子), is China's first domestically produced BNCT system. In 2026, the system completed registration inspection and entered clinical trials.

Technology Components

HyBorSys® comprises a full-chain solution:

• Neutron source — an accelerator-based neutron source that produces epithermal neutrons suitable for BNCT
• Boron-10 drug — a proprietary boron-containing compound with high tumor-to-normal tissue selectivity
• Treatment planning software — a dedicated system for dose calculation and treatment optimization

Clinical Trial Progress

Clinical trials of the HyBorSys® system are being conducted at multiple Chinese centers, with initial focus on:

• Glioblastoma — an aggressive brain cancer with a median survival of just 12–15 months, even with aggressive treatment
• Recurrent head and neck cancer — patients who have failed conventional radiation therapy and have few remaining options
• Melanoma — skin cancers that are resistant to conventional therapy

Preliminary results from the first patients treated in China have been encouraging, with some patients achieving durable responses without significant toxicity.

IV. Global Context: China's Position in the BNCT Race

China joins a small group of countries actively developing BNCT, including Japan (where BNCT has been approved for certain indications), Finland, and the United States. China's advantages include:

• Fully integrated, full-chain development — from neutron source to boron drug, all developed in-house
• Accelerated regulatory pathway — BNCT systems have been accepted into NMPA's innovative device review process
• Large patient population — China's substantial cancer burden provides abundant clinical trial opportunities

V. Indications and Future Directions

While current trials focus on glioblastoma and head and neck cancer, the potential applications of BNCT are much broader:

• Brain tumors — including metastatic brain tumors
• Head and neck squamous cell carcinoma — particularly recurrent cases
• Liver cancer — using boron-10 drugs that localize in liver tumors
• Lung cancer — selected cases

VI. What This Means for International Patients

For international patients seeking BNCT treatment:

• Access to a cutting-edge therapy — BNCT is not yet widely available in most countries
• Clinical trial participation — patients may be able to access BNCT through clinical trials
• Cost advantage — BNCT in China is expected to be significantly more affordable than in other countries where the therapy is available

Conclusion

BNCT represents a completely new approach to cancer treatment — one that combines the targeting precision of immunotherapy with the cell-killing power of radiation. China's progress in developing the HyBorSys® system and advancing it into clinical trials positions the country as a global leader in this emerging field.