January 9, 2025 — A novel timing tool developed at Poland's Cyclotron Center Bronowice could allow proton beam energy to be verified just before nearly every radiotherapy session, dramatically boosting treatment precision and patient safety.
The system, unveiled today by researchers at the Institute of Nuclear Physics, Polish Academy of Sciences, measures the time it takes for individual protons to travel a fixed distance. By analyzing these flight times, clinicians can determine beam energy with high accuracy in seconds.
“This is a game-changer for quality assurance in proton therapy,” said Dr. Katarzyna Nowak, lead physicist on the project. “Previously, energy checks were done only periodically. Now we can confirm the correct dose delivery before every fraction.”
Background
Proton therapy uses high-energy protons to destroy cancer cells while sparing surrounding healthy tissue. Unlike conventional X-rays, protons deposit most of their energy at a specific depth — the Bragg peak. This makes beam energy critical: a slight deviation can miss the tumor or damage sensitive organs.
The Cyclotron Center Bronowice has been at the forefront of proton therapy research. Their existing facility treats hundreds of patients annually, but until now energy verification required time-consuming equipment setup, often performed only weekly.
The new timing apparatus, which fits inside the treatment nozzle, requires no moving parts or external calibration. It automatically records proton arrival times and computes the energy spectrum in real time.
How the Tool Works
The device uses a fast scintillator and photodetector to capture the passage of individual protons. A precise electronic clock measures the time difference between two detection points separated by about 10 centimeters.
“By knowing the distance and the measured time, we can calculate velocity and thus kinetic energy,” explained Dr. Nowak. “This gives us a direct, non-invasive check of the beam as it exits the nozzle.”
Preliminary tests show the tool can detect energy deviations as small as 0.5% — well within clinical tolerance. The system also flags beam instabilities that could affect treatment outcome.
What This Means
If implemented widely, the timing tool could enable per‑fraction energy verification for every patient, eliminating the reliance on infrequent spot checks. This would reduce the risk of under‑ or overdosing tumors, particularly in complex cases like treatment near the spinal cord or eyes.
“This technology could become a standard component of all proton therapy machines,” said Prof. Adam Wiśniewski, director of the Institute of Nuclear Physics. “It makes the treatment inherently safer and more reliable.”
The method also simplifies regulatory compliance: many health authorities require daily energy measurements for treatment units. The timing tool provides instant, automated logging of each beam pulse.
Beyond energy verification, researchers are exploring whether the tool can measure beam position and intensity simultaneously, further streamlining quality assurance.
Next Steps
The team is now working on a compact, ruggedized version suitable for commercial installation. They plan to begin clinical testing at Bronowice later this year, with partners at other proton therapy centers expressing interest.
“Our goal is to make this an integrated, plug‑and‑play solution,” Dr. Nowak said. “We want every treatment room to have this capability without adding complexity for the operators.”
Funding for the project came from the National Science Centre and the European Regional Development Fund. A patent application has been filed.
For more details on proton therapy principles, see our Background section.