APBI, accelerated partial breast irradiation; ART; ART, adaptive radiotherapy; BED, biologically equivalent dose; CAGR, compound annual growth rate; CBCT, cone beam computerized tomography; Care patterns; GDPR, General Data Protection Regulation; Gy, gray; H&N, head and neck; HIPAA, Health Insurance Portability and Accountability Act; IGRT, image-guided radiation therapy; MR, magnetic resonance; MR-IGRT; MRI, magnetic resonance imaging; MRI-guided radiotherapy; MRIdian, 0.35Tesla(T)-MRgRT; MRgRT, magnetic resonance-guided radiotherapy; MVCT, mega-voltage CT; NSCLC, non-small cell lung cancer; OAR, organs at risk; On-table adaptive radiation therapy; PHI, protected health information; PTV, planning target volume; RT, radiation therapy; SABR, stereotactic ablative radiation therapy; SBRT; SBRT, stereotactic body radiotherapy; Stereotactic body radiotherapy; T, Tesla; UHfx, ultra-hypofractionated; linac, linear accelerator; oART; oART, on-table adaptive radiation therapy