| AHRQ/ASTRO review (Skelly et al. 2023) | Single fraction and multiple fraction EBRT likely have similar overall pain response; single fraction associated with higher re-irradiation |
| Randomized trials (Hartsell 2005; Chow) | 8 Gy single fraction comparable for pain relief with higher retreatment rates vs multi-fraction regimens |
| Migliorini meta-analysis (2021) | 8 Gy single fraction produced strong pain control and lower reirradiation in pooled analysis of skeletal metastases regimens |
| Breast trials (Brunt 2020; START; Whelan 2010) | Hypofractionated schedules (e.g., 26 Gy in 5 fx; 40 Gy in 15; 42.5 Gy in 16) are non-inferior with acceptable toxicity and fewer normal tissue effects |
| ASTRO PBI guidance (Shaitelman 2023) | Recommended external beam PBI regimens: 3000 cGy in 5 fractions and 4005 cGy in 15 fractions |
| NICE (2018/2024) | Recommends DIBH for left-sided breast and offers 26 Gy in 5 fractions and 40 Gy in 15 fractions in specified settings |
| RTOG/NRG lung trial (Bradley/RTOG0617 2015) | High-dose 74 Gy with concurrent chemo worse than 60 Gy; standard curative chemoradiation is 60 Gy in 2 Gy fractions |
| Prostate trials and reviews (Catton 2017; Dearnaley CHHiP 2016; HYPRO; Cochrane/Hickey 2019) | Moderate hypofractionation (e.g., 60 Gy/20 fx or 3 Gy×20) is noninferior to conventional dosing for many patients; very large fraction sizes (HYPRO 3.4 Gy) had mixed toxicity results |
| IGRT meta-analysis (Wang 2022) | IGRT reduced acute GU and GI toxicity and improved biochemical/tumor control; daily IGRT better than weekly |
| IGRT practice and outcomes studies (Kilburn 2016; Yao 2019; Lin 2012; Korreman 2012) | Evidence supports IGRT for margin reduction, improved local control in lung, reduced late toxicity in extremity sarcoma, and imaging schedule tailoring by site and BMI |
| ACR-ASTRO Practice Parameter and ASTRO guidance | IGRT increases accuracy, applicable to highly conformal modalities; recommends techniques, indications, and safety/QA processes |
| ASTRO coding/resource notes and policy coding clarifications | IGRT coding clarifications: not separately reportable with SBRT/SRS, and not for brachytherapy imaging; special services coding rules described |
| NCCN guidelines (various) | Strong recommendations for IGRT in multiple tumor sites when using RT/IMRT/SBRT to improve accuracy and reduce toxicity; daily prostate localization essential |
| ESTRO/ACROP and guideline summaries | Guidance for bone metastases fractionation (e.g., single 8 Gy or fractionated regimens) and recommendations for reirradiation contexts |
| ASTRO safety/white paper and QA guidance (Qi et al. 2023; Jaffray 2013) | IGRT is resource intensive and requires SOPs, interdisciplinary staffing, and comprehensive QA programs |
| Multiple ASTRO site-specific guideline recommendations | ASTRO recommends daily IGRT or motion management for liver, pancreas, oligometastatic NSCLC, soft tissue sarcoma, and other sites |