Yttrium-90 (Y) brachytherapy for squamous carcinoma: Treatment of the conjunctiva, cornea, and sclera.

Purpose: Patients with conjunctival squamous cell carcinoma that present with persisting disease or recurrence following topical chemotherapy and/or surgery especially when invading the sclera are challenging to treat. Herein, we describe the use of high-dose-rate (HDR), FDA-cleared, yttrium-90 (Y) plaque brachytherapy for such lesions.

Observation: Three cases of invasive conjunctival squamous cell carcinoma that had exhibited a poor response or recurrence following topical chemotherapy and/or surgery are described. As treatment, HDR Y beta-radiation was applied to the tumor and margins for a single, continuous duration. In contrast to low-dose-rate (LDR) plaque, HDR Y brachytherapy did not require episcleral sutures, amniotic membrane buffering of the cornea, a Gunderson flap, outpatient dwell time, or second surgery. Radiation safety was improved by eliminating LDR-implant related post-operative radiation exposure to health care personnel, the community, family, and pets. Follow-up examination at one month revealed complete tumor resolution in all patients. At last follow-up (8, 11 and 18 months) all patients remained clinically tumor-free as confirmed by slit-lamp biomicroscopy, anterior segment optical coherence tomography, and high-frequency ultrasound imaging. There were no acute complications (e.g., corneal edema, iridocyclitis, scleropathy, keratopathy or cataract).

Conclusion And Importance: Y brachytherapy demonstrated efficacy as a single-surgery, minimally invasive, outpatient irradiation for squamous carcinoma of the ocular surface. While short-term results were promising, long-term follow-up monitoring for side-effects and recurrence are essential.