Importance: Conjunctival squamous cell carcinoma (SCC) is surgically managed with wide surgical excisional biopsy, superficial keratectomy, and cryotherapy. In eyes with residual tumor showing scleral invasion or intraocular involvement, enucleation is advised.
Objective: To explore the role of plaque radiotherapy for residual invasive conjunctival SCC as an alternative to enucleation.
Design, setting, and participants: Interventional case series involving 15 patients with histopathologically confirmed scleral and/or intraocular invasion of SCC at Wills Eye Hospital.
Intervention: Plaque radiotherapy.
Main outcomes and measures: Tumor control, treatment complications, and globe salvage.
Results: The primary tumor prior to excision displayed a mean basal diameter of 12.1 mm (median, 12 mm; range, 4-25 mm) and mean thickness of 2.6 mm (median, 3 mm; range, 1-5 mm). In all cases, the tumor was managed by primary surgical resection using wide excisional biopsy, limited superficial keratectomy, and cryotherapy to the remaining conjunctival margins. Histopathology confirmed conjunctival SCC in all cases with residual tumor demonstrating scleral invasion (n = 15) and/or anterior chamber invasion (n = 3). The residual tumor measured a mean basal diameter of 10.6 mm (median, 10 mm; range, 2.5-20 mm) and mean thickness of 1.5 mm (median, 1 mm; range, 1-5 mm). Plaque radiotherapy was applied in all cases for a mean apex dose of 56 Gy (median, 50 Gy; range, 50-80 Gy) over a mean of 132 hours (median, 142 hours; range, 93-170 hours). Over a mean follow-up of 41 months (median, 46 months; range, 9-96 months), local tumor control was achieved in all 15 cases (100%). However, 4 cases showed further distant conjunctival tumor recurrence remote from the site of radiotherapy with positive orbital involvement at a mean of 5 months postradiotherapy, necessitating enucleation (n = 2) or orbital exenteration (n = 2). Globe salvage was achieved in 10 cases, as 1 patient required enucleation for chronic ocular irritation. Radiation complications included cataract (n = 13), iris telangiectasia (n = 5), corneal epithelial defect (n = 4), corneal edema (n = 3), and glaucoma (n = 1). There was no evidence of metastasis.
Conclusions and relevance: Plaque radiotherapy delivered over a mean of 6 days can be an effective alternative to enucleation for residual scleral-invasive conjunctival SCC following resection. Local tumor control was achieved in all cases.