Assessment of additional radiation exposure associated with various imaging modalities in image-guided radiation therapy
RADIATION MEASUREMENTS, cilt.197, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 197
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.radmeas.2026.107770
- Dergi Adı: RADIATION MEASUREMENTS
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Dokuz Eylül Üniversitesi Adresli: Evet
Özet
Image-guided radiation therapy (IGRT) techniques using computed tomography (CT) and cone-beam CT (CBCT) expose patients to additional radiation. While several dosimetric approaches have been used in earlier research, there is a need for a comprehensive, multi-modality evaluation of absolute organ doses that fully accounts for tissue inhomogeneities using thermoluminescent dosimeters (TLDs). This study aims to compare absolute absorbed doses to 18 critical organs using TLDs within an anthropomorphic phantom across five distinct IGRT techniques on a single platform. To evaluate the radiation doses to key organs in the head-and-neck, thorax, and pelvis, TLDs were placed inside matching anatomical areas of the phantom. For each region, CT, kV-MV port, and CBCT scans (using 200 degrees and 360 degrees, both filtered and unfiltered) were conducted with only that region's TLDs inserted. The absorbed doses were then measured for each modality and body site. Each measurement was repeated three times per technique and region, with mean values reported as the per-fraction dose. Cumulative imaging doses were estimated by multiplying these averages by standard numbers of therapeutic fractions. Dose contributions varied with imaging technique and settings, with standard deviations of per-fraction doses ranging from +0.002 to +0.049 cGy. Mean total regional absorbed doses (Dregion) for complete treatment courses across all monitored organs-at-risk were: 0.66 cGy (CT, single fraction), 1.06 cGy (kV port), 1.34 cGy (unfiltered CBCT), 46.07 cGy (filtered CBCT), and 94.53 cGy (MV port). Doses delivered to critical organs vary widely between IGRT protocols. CBCT, particularly with larger arc angles and higher mAs, delivers the largest dose. Clinical decisions should weigh the need for precise imaging against patient safety by selecting parameters consistent with the ALARA (As Low As Reasonably Achievable) principle.