Histopathology-guided management of ocular surface squamous neoplasia with corneal stromal or scleral invasion using ruthenium-106 plaque brachytherapy.

BACKGROUND/AIM: To evaluate the safety and efficacy of ruthenium-106 (Ru-106) plaque brachytherapy in managing invasive ocular surface squamous neoplasia (OSSN).

METHODS

This is a retrospective, non-comparative, interventional case series of 42 eyes with OSSN with histopathologically-proven corneal stromal and/or scleral invasion that underwent Ru-106 plaque brachytherapy. Main outcome measures were tumour regression, eye salvage, final visual acuity, treatment complications and metastasis.

RESULTS

At presentation, the mean tumour basal diameter was 9.3 mm (range 5-26 mm) and thickness 3.1 mm (range 1.5-11 mm). Prior treatment included excision biopsy in two patients (5%), incision biopsy and topical interferon in one each (2%). Following excision with 4 mm clinically clear margins, corneal stromal and/or scleral invasion of OSSN was confirmed in all 42 cases, with the excised base showing invasive squamous cell carcinoma. A total dose of 5000 cGy over a mean duration of 19.7 hours (range 7-41 hours) was provided to an axial depth of 2 mm using Ru-106 surface plaque. Over a mean follow-up of 36.9 months (range 22.3-72 months), complete tumour regression was achieved in all eyes (100%). Two eyes (5%) showed conjunctival tumour growth remote from the site of prior treatment. Visual acuity was maintained at ≥20/200 in 35 eyes (83%), with a loss of >2 Snellen lines in 1 eye (2%). There was no evidence of regional lymph node or systemic metastasis.

CONCLUSION

Histopathology-guided use of Ru-106 surface plaque brachytherapy is a safe and an effective adjuvant therapy in the management of corneal stromal and/or scleral invasion of OSSN.