Iodine-125 plaque brachytherapy for aggressive squamous cell carcinoma with corneal and scleral invasion.

A 79-year-old Iraqi man with a history of ocular surface squamous neoplasia (OSSN) was referred for evaluation of corneal opacification in the left eye. He had been treated at an outside institution where lesion excision was twice performed – one several years earlier and another more recently a few months earlier. He described left eye progressive blurry vision, pain, and burning sensation. His medical history included myasthenia gravis with thymectomy and locally treated prostate cancer. He had no known immunocompromise and was a nonsmoker. Spectacle-corrected visual acuity was 20/30 in both eyes. Intraocular pressure was 15 mmHg in both eyes. Slit-lamp examination of the left eye [Figure 1] revealed a large temporal area of corneal stromal opacification with neovascularization and adjacent conjunctival rose bengal staining and a clear unremarkable cornea in the fellow eye. He was pseudophakic bilaterally. Ultrasound biomicroscopy [Figure 2] and anterior segment optical coherence tomography [Figure 3] showed significant corneal stromal thickening with deep corneal stromal invasion and possible involvement of the angle. He had no appreciable lymphadenopathy.

Figure 1

Slit-lamp photograph of the left eye demonstrating 6.0 mm × 10.5 mm temporal area of corneal opacification with deep stromal tumor invasion and neovascularization

Figure 2

Ultrasound biomicroscopy longitudinal 6 o’clock section demonstrating a nodular component of the intrastromal tumor causing posterior bowing of the cornea and narrowing of the angle. The thickness of the tumor was 1.53 mm

Figure 3

Anterior segment optical coherence tomography demonstrating deep stromal invasion by the tumor and abnormal hyperreflectivity in the corneal epithelium

Conjunctival biopsy histopathology was reviewed and found to show squamous cell carcinoma (SCC) with focal glandular features and negative immunohistochemical staining for BerEP4. The absence of BerEP4 immunoreactivity in the lesion made adenosquamous carcinoma less likely.[1] The patient underwent Iodine-125 (125I) plaque brachytherapy, utilizing conjunctival/scleral fixation of a 16 mm plaque to a depth of 1.6 mm, delivering 60 Gy. The plaque was removed 1 week later. The patient had regression of the tumor and vessels but residual lipid keratopathy [Figures 4 and 5], and at most recent follow-up 10 months after brachytherapy, he had visual acuity of 20/25 in the treated eye with no tumor regrowth.

Figure 4

Three months after 125I plaque radiotherapy, ultrasound biomicroscopy longitudinal 6 o’clock section. In comparison to the similarly oriented section of Figure 1b, there is interval regression of the tumor. Posterior bowing of the cornea narrowing the angle has greatly improved

Figure 5

Seven months after I125 plaque radiotherapy, posttreatment slit-lamp photograph showing regression of feeder vessels to the intrastromal tumor

This patient's residual/recurrent tumor and substantial local invasion of the cornea necessitated aggressive therapy. Although topical therapy (including mitomycin C, 5-fluorouracil, interferon alpha-2b) is the mainstay of treatment for OSSN, these agents may have inadequate tissue penetrance when there is intraocular, intracorneal, or intrascleral invasion.[23] In patients with significant ocular invasive disease and unresectable cases, enucleation and plaque radiotherapy are both indicated treatment modalities.[23] The patient should be counseled in detail about the risks and benefits of either procedure. Enucleation presents the opportunity for source control of locally invasive tumors that have not metastasized and may be especially well suited to large tumors with diffuse or extensive invasion of the globe.[24] 125I plaque radiotherapy, a globe-sparing therapy, has been shown in multiple retrospective studies to be efficacious against locally invasive OSSN.[35] In these prior studies, local control of the primary lesion was achieved in all patients, although a minority of patients later developed distal conjunctival recurrence.[35] Other potential complications of plaque radiotherapy include secondary cataracts, corneal ulceration or edema, iris telangiectasia, or glaucoma.[35] Plaque radiotherapy does not preclude future treatment with enucleation if plaque radiotherapy fails.[3] In the current case, the patient's sectoral tumor appeared well suited to local treatment with plaque radiotherapy; accordingly, globe salvage with I125 was considered preferable to enucleation, and this treatment approach was pursued in this case patient with good oncologic and visual outcome.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

This work was supported by the Grant NIH K12EY021475, Eversight Eye Bank Research Grant, and an Unrestricted Departmental Grant from the Research to Prevent Blindness.

Conflicts of interest

There are no conflicts of interest.