Adjuvant radiation treatment is often offered for lacrimal sac tumors. However, due to the adjacent critical structures, conventional radiation technique may result in severe side effects. We have treated two patients with lacrimal sac tumors using optically guided stereotactic radiotherapy. One patient with lacrimal sac melanoma was treated with optical-guidance intensity-modulated radiotherapy (IMRT). The other with mixed transitional and squamous cell carcinoma was treated with optical-guidance 3-D conformal radiation. Dose volume analysis revealed excellent target coverage and sparing of critical structures. Both patients tolerated the treatment well with no significant acute or late side effects. One patient died of metastatic melanoma 30 months after radiation; another died of coexisting disease 41 months after radiation. Both had no clinical evidence of local recurrence at the time of death. Our report show that optically guided stereotactic radiotherapy is well tolerated. It offers excellent tumor coverage and sparing of critical structures. It can be used for tumors adjacent to radiation sensitive critical structures such as skull base tumors.

Key words: Lacrimal sac tumor; Radiotherapy; Stereotactic; Intensity modulated radiotherapy; and Optical guidance.