Abstract
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 (90Y) plaque brachytherapy for such lesions.
Methods :
Three cases of invasive conjunctival squamous cell carcinoma that had exhibited a poor response or recurrence following topical chemotherapy and/or surgery were included.
Patient 1 had tumor dimensions of: 4.0 (length) x 3.5 mm (breadth) and 1.7mm (height).
Patient 2 had tumor dimensions of: 6.0 (length) x 5.0 mm (breadth) and 2.0 mm (height).
Patient 3 had tumor dimensions of: 5.0 (length) x 3.0 mm (breadth) and 0.8 mm (height).
HDR 90Y beta-irradiation was applied to the tumor and margins for a single, continuous duration.
Patient 1 received a HDR of 22 Gy for a total application time of 5 minutes 56 seconds.
Patient 2 received a HDR of 25 Gy for a total application time of 5 minutes 17 seconds.
Patient 3 received a HDR of 30 Gy for a total application time of 2 minutes 16 seconds.
Results :
Follow-up examination at one month revealed complete tumor resolution in all 3 patients. At their last follow-up evaluations 3, 4 and 13 months out respectively, all patients remained clinically tumor-free as confirmed by slit-lamp biomicroscopy, gonioscopy, and high-frequency ultrasound imaging. At last follow-up there were no acute complications (e.g., corneal edema, iridocyclitis, scleropathy, keratopathy or cataract). In contrast to low-dose-rate (LDR) plaque, HDR 90Y 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.
Conclusions :
HDR 90Y 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 is essential to monitor for side-effects and recurrence.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.