Radio- KO Radiotherapy for Knee Osteoarthritis Clinical Trial

Inclusion Criteria: * age 50-85 years * ICOAP pain scale A1 at least moderate intensity or B6 at least moderate intensity * diagnosed with primary knee OA ICD-10 codes M17.x * history of morning stiffness in knees that lasts less than 30 minutes * history of crepitus without a history of warmth, redness or sudden onset of swelling * physical exam findings of medial or lateral joint line tenderness on palpation that is in the same location as the knee pain for which their primary care provider has ordered an intraarticular steroid injection into the same knee. * absence of primary knee pain in the pes anserine or hamstring or gastrocnemius tendons * radiographic Kellgren-Lawrence grade 2-3 on 4-view knee x-rays taken within the last year * ability to complete surveys in English Exclusion Criteria: * Kellgren-Lawrence grade 1 or 4 * pregnancy or women 54 years and younger with potential for pregnancy (if they or their partner have not had tubal ligation, hysterectomy, or vasectomy) * history of ipsilateral intraarticular knee surgery * use of injected corticosteroids within 3 months or hyaluronans within 6 months or within 1 month if there was no sustained improvement post-injection of either corticosteroid or hyaluronan. * history of trauma to this knee in the last year that clearly caused the pain now present * history of RA, gout, pseudogout, hemarthroses (eg, hemophilic arthropathy) or other inflammatory arthritis involving this knee * history of symptomatic hip OA * history of psychosis, personality disorder, uncontrolled affective disorder * history of fibromyalgia * malignancy requiring active treatment * current regular use of opiate analgesics, PRP, or acupuncture for the knees