Highlights:
- New configurable γ photon spectrometer developed for high-precision radioguided tumor resection.
- CMOS-based integrated circuit measuring 9.9 mm² enables sub-keV energy resolution of single γ photons.
- Innovative low-power energy spectrometry method measures signal decay time rather than direct voltage drop.
- Tested on multiple radioisotopes, achieving 1.315 MeV dynamic range and high sensitivity down to 1 µCi activity.
TLDR:
A team of researchers has developed a compact, configurable γ photon spectrometer using CMOS technology that allows surgeons to detect cancer cells with unprecedented precision during radioguided tumor resections, potentially minimizing recurrence risk.
In a significant advancement for cancer surgery technology, researchers Rahul Lall, Youngho Seo, Ali M. Niknejad, and Mekhail Anwar have unveiled a configurable γ photon spectrometer designed to enhance precision during radioguided tumor resections. Surgical oncology has long faced the challenge of fully removing malignant tissue without harming healthy margins, as microscopic cancer clusters often elude visual or manual detection. This new integrated circuit (IC)-based spectrometer, measuring just 9.9 mm², allows for the selective identification of γ photon-emitting cancer-tagged cells in real time, offering surgeons the tools to improve resection accuracy and reduce recurrence rates.
This innovative spectrometer, developed using a 180 nm CMOS process, directly measures the energy of single γ photons with sub-keV energy resolution. The system employs ultra-small 2×2 μm reverse-biased diodes characterized by low depletion region capacitance, producing millivolt-scale voltage signals when interacting with γ photon charges. The device’s unique spectrometry approach avoids traditional high-power, direct-voltage measurement techniques by instead capturing the decay time it takes for voltage signals to return to DC levels after detection events. This measurement technique significantly reduces power consumption while preserving high energy resolution, making the design particularly suited for portable, intraoperative medical instruments.
To further enhance adaptability in clinical conditions, the team implemented three distinct pixel architectures within the spectrometer. These architectures enable surgical teams to configure pixel sensitivity, energy resolution, and energy dynamic range to accommodate a wide range of tumor types and patient anatomies. During tests with three common γ-emitting radioisotopes — ⁶⁴Cu, ¹³³Ba, and ¹⁷⁷Lu — the system demonstrated its ability to resolve activity levels as low as 1 µCi, achieving a dynamic energy range up to 1.315 MeV within five-minute acquisitions. This configurable approach positions the technology as a breakthrough in the field of radioguided surgery (RGS), merging electrical engineering and oncology to empower more complete cancer resections under minimal power and compact design constraints.
Source:
Source:
https://doi.org/10.1109/TBCAS.2025.3625580