Radiotherapy for Refractory Hidradenitis Suppurativa

Inclusion Criteria: * Male or female subjects between the age of 18 or older with moderate or severe HS (Hurley Stage II or III) with bilateral axillary disease of approximately equivalent disease severity will be included. * Patients on topical and/or systemic HS medications for at least 1 month will continue maintenance treatment throughout the study period as per standard of care. * Patients willing and able to provide informed consent Exclusion Criteria: * Pregnancy - Women of childbearing potential must use trial approved birth control and obtain a negative pregnancy test 7 days prior to radiotherapy CT simulation. * Severe autoimmune conditions including lupus, scleroderma and mixed connective tissue disease * Poorly controlled diabetes per physician discretion, HIV, Hepatitis B/C. * Prior therapeutic radiotherapy. * Active malignancy. * Contraindication to radiotherapy as determined by treating radiation oncologist. * Patients who began new systemic treatment for their HS \<1 month prior to enrollment in trial * History of photosensitivity disorders or prior radiation sensitization syndromes * Any contraindication to radiotherapy as determined by the treating radiation oncologist.