Cherenkov-excited fluorescence imaging for small-field dosimetry and SRS plan verification: a feasibility study

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Enkavi M. F., Uysal H., Oysul K., Sirin S., ERŞAN Y. Ç.

Physics in Medicine and Biology, cilt.71, sa.19, 2026 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 71 Sayı: 19
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1088/1361-6560/aea5cf
  • Dergi Adı: Physics in Medicine and Biology
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Compendex, EMBASE, INSPEC, MEDLINE, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
  • Anahtar Kelimeler: Cherenkov-excited fluorescence imaging, optical dosimetry, plan verification, small-field, stereotactic radiosurgery
  • Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
  • Hacettepe Üniversitesi Adresli: Evet

Özet

Objective. To develop a high-spatial-resolution Cherenkov-excited fluorescence dosimetry system (CEFD) with rapid optical readout using quinine sulfate solution and evaluate its feasibility for small-field dosimetry and verification of patient-derived stereotactic radiosurgery (SRS) dose distributions. Approach. A 3D-printed optical phantom containing 1 g l−1 quinine sulfate solution was imaged with a complementary metal-oxide-semiconductor camera through a 45° mirror. Sensitive-volume thicknesses of 2.5, 5, 10 and 15 mm were compared using calibration response, signal-to-noise ratio, output factors, dose-rate dependence, and small-field beam profiles benchmarked against a PTW 60023 microSilicon detector. The selected CEFD configuration was further evaluated for thermal response, repeatability, signal drift, low-MU response, and small-field gamma performance, and then used for fixed-gantry verification of 31 patient-derived SRS dose distributions. GafChromic EBT3 film was used as the high-spatial-resolution comparator. Main results. The CEFD achieved 0.065 mm pixel−1 spatial sampling. CEFD-10 showed the most balanced overall performance across sensitivity, dose-rate response, output-factor agreement, and small-field profile measurements. Dose-rate deviations remained within 1.7% at 300–1400 MU min−1. Passive heat sinking reduced the coefficient of variation from 0.26%–0.13% and limited signal drift from 4.3%–0.97% over 30 consecutive measurements. For the 0.5 × 0.5 cm2 field, the CEFD-10 central-axis dose ratio relative to the treatment planning system-projected dose remained within ±2% from 10 MU onward. For 0.5 × 0.5–3 × 3 cm2 static fields, CEFD-10 achieved 99.56%–100.0% global 2%/1 mm gamma passing rates with a 10% low-dose threshold. For patient-derived SRS verification, CEFD-10 achieved mean global gamma passing rates of 99.47 ± 1.58% and 97.53 ± 3.58% for 2%/2 mm and 2%/1 mm criteria, respectively, with mean differences from EBT3 film of −0.32% and −0.21%, respectively. Significance. This study demonstrates compact, high-spatial-resolution, rapid-readout optical dosimetry for small-field and patient-derived SRS dose patterns. Agreement with EBT3 film supports CEFD-10 as a controlled-geometry SRS dose verification.