Radiotherapy 12Gy in 6 Fractions For Orbital Lymphoma

Inclusion Criteria: * Age ≥18 years with stage I-IV indolent NHL\* * Able to provide informed consent * Histologically confirmed indolent NHL involving one or both orbits. If bilateral, biopsy of only one orbit is permitted as long as high clinical suspicion of contralateral orbit involvement * Measurable orbital disease after biopsy, either clinically or radiographically * ECOG performance status 0-3 * Life expectancy \>12 months * Available for treatment and follow-up (including scheduled post-treatment imaging and ophthalmologic exam) * Able and willing to complete quality of life questionnaires via paper or online portal if they provide their email address on the informed consent document * Stage II-IV allowed but if systemic therapy given after RT the timing will be recorded, and subjects will be stratified according to receipt of systemic therapy Exclusion Criteria: * Aggressive NHL histology (including grade 3B follicular lymphoma) * Prior RT to orbit * Patients requiring treatments outside standard clinical hours * Systemic therapy for lymphoma is not permitted within the period of time between 2 weeks prior to RT start and 2 weeks after RT completion * Patients who are pregnant * History of other malignancy within 5 years prior to screening, with the exception of those with a negligible risk of metastasis or death and/or treated with expected curative outcome (for example, appropriately treated non-melanoma skin cancer, carcinoma in-situ of the cervix, localized prostate cancer, breast ductal carcinoma in-situ, or stage I endometrial cancer) * Any medical condition that, in the investigator's judgement, would preclude the individual's safe participation in and completion of the study, or could affect interpretation of the results (e.g. pre-existing retinopathy, active connective tissue disease) * Inability to comply with study and follow-up procedures