Salvage ultra-low-dose radiotherapy for conjunctival mantle cell lymphoma - a case report and literature review.

Orbital involvement is rare, and data on radiotherapy, particularly at ultra-low doses, remain limited.

The authors report a 64-year-old male with conjunctival mantle cell lymphoma refractory to a single cycle of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone).

He underwent salvage ultra-low-dose radiotherapy (VLDRT; 4 Gy in 2 fractions) to the left orbit using volumetric modulated arc therapy (volumetric modulated arc therapy) with 6 MV photons, daily cone beam computed tomography (cone beam computed tomography) image guidance, thermoplastic mask immobilization, and a 0.5 cm bolus.