Globe-preserving surgery with PBR offers favorable long-term outcomes

The current study describes the outcomes of globe-preserving surgery combined with high-dose proton beam radiation (PBR) in treating patients with primary adenoid cystic carcinoma (ACC) of the lacrimal gland.

Study design

The authors retrospectively reviewed records from 18 patients with ACC of the lacrimal gland who underwent surgical resection and PBR. Patients were followed for a median of 12.9 years after treatment completion.

Outcomes

The study found that overall survival and disease-free survival was superior in the group that underwent globe-preserving surgery with PBR compared with historical and alternative treatment groups that underwent a mixture of exenteration, limited resection, radiation and intra-arterial chemotherapy.

Three adult patients died of metastatic disease at a median of 4.2 years after treatment, and 4 developed local recurrences. Useful vision (20/40 or better) was retained for a median 3 years. Radiation morbidity included brain injury, retinopathy, optic neuropathy, keratopathy and cataract.

Limitations

This was a retrospective study with a small sample size, which is to be expected given the rarity of this condition. Although the sample is from a single institution, it combines data from multiple surgeons who used various techniques to accomplish various goals.  Furthermore, it is difficult to classify ACC due to the heterogeneities in tumor histopathology. The tumors were grouped into reasonable categories based on an experienced pathologist's interpretation, but these groups are arbitrary. The study included 1 patient who had basaloid subtype without evidence of metastasis, but the follow-up time was only 7 months.  

Clinical significance

The authors advocate for the use of globe-preserving surgery with PBR because of the better survival and the prolongation of useful vision.