Karin Lecuona

Postenucleation orbits in retinoblastoma: treatment with 125I brachytherapy

PURPOSE Children with retinoblastoma that extends into or through the choroid, sclera, or optic nerve are at risk of developing orbital disease, as well as metastases. Previously, these enucleated orbits were treated with external beam radiotherapy in addition to chemotherapy. 125I brachytherapy for tumors in and around the eye was pioneered by Sealy in Cape Town, South Africa, in 1974. In 1983, he developed a technique to irradiate the contents of the orbit while limiting the dose to the bony orbit and eyelids. METHODS AND MATERIALS Six nylon tubes containing 125I seeds were implanted through the eyelids around the periphery of the orbit. Each contained a metal gutter that screens the outer part of the seeds from the bony orbit. A seventh unscreened tube was placed in the center, and a metal disc with 125I seeds on its posterior surface was secured beneath the eyelids. Between 1983 and 2000, 57 orbits were treated in 56 children with retinoblastoma. Thirty-six were treated prophylactically and 21, with tumor at the resection line of the nerve, extrascleral tumor, or metastases, were treated therapeutically. They received a median dose of 34 Gy in 70 h; 30 also received chemotherapy. Children with tumor at the resection line of the nerve also received treatment to the craniospinal axis. RESULTS The median follow-up of the 35 patients treated prophylactically was 35 months (range 0-187). Seven patients died, 6 of metastases, at a median of 10 months (range 4-29) after the implant. Eight of the 13 patients with microscopic extraocular tumor survived a median of 29 months (range 5-156). None of the 8 patients presenting with orbital tumor or metastases survived. No orbital recurrences developed in any of the patients. Cosmesis was considerably improved compared with previous forms of irradiation. CONCLUSION Orbital brachytherapy is an effective method of irradiating the orbit to prevent recurrent tumor, the treatment time is short, and the cosmesis is much more acceptable than with other forms of irradiation. No facial atrophy or second nonocular tumors have occurred.

Iodine-125 orbital brachytherapy with a prosthetic implant in situ.

AbstractPurpose: Brachytherapy is one method of irradiating the orbit after enucleation of an eye with a malignant tumor that has a potential to recur. It consists of 6 trains of I-125 seeds placed around the periphery of the orbit, a shorter central train, and a metal disc, loaded with seeds, placed beneath the eyelids. The presence of a prosthetic orbital implant requires omission of the central train and adjustment of the activity of the seeds in the anterior orbit around the prosthesis.Patients and Methods:This is a retrospective review of the technical modifications and outcome of 12 patients treated in this manner: 6 with retinoblastoma, 5 with malignant melanoma, and 1 with an intraocular rhabdomyosarcoma. The median dose was 35.5 Gy in 73 hours for retinoblastoma and 56 Gy in 141 hours for malignant melanoma. Patients with retinoblastoma and rhabdomyosarcoma also received chemotherapy.Results:The tubes can be placed satisfactorily around the prosthesis. The increased activity in the anterior half of the tubes produced comparable dose distributions. There have been no orbital recurrences, no extrusion of the prosthesis, and cosmesis is good.Conclusion:Insertion of a prosthetic implant at the time of enucleation greatly enhances the subsequent cosmetic appear-ance. This should be encouraged unless there is frank tumor in the orbit. Orbital brachytherapy without the central train continues to give excellent local control. The short treatment time and good cosmesis are added advantages. The patient is spared the expense and inconvenience of removing and replacing the prosthetic implant.ZusammenfassungHintergrund:Bei hohem intraorbitalen Rezidivrisiko nach Enukleation eines tumortragenden Auges kann die Orbita mit einer I-125 Brachytherapietechnik schonend bestrahlt werden. Dabei werden 6 I-125 Seed-trains zirkulär in der Orbita platziert, zusammen mit einem kürzeren zentralen Seed-train und einem münzförmigen Applikator hinter den Lidern, mit der strahlenden Seite in Richtung Orbita. Inzwischen wird nach Enukleation häufig ein kugelförmiges intraorbitales Implant zur Verbesserung der Kosmetik eingebracht, so dass eine Adaptation dieser Technik notwendig wird. Der zentrale Seed-train entfällt, die Aktivität der peripheren Applikatoren muss angepasst werden.Patienten und Methodik:Die technischen Modifikationen und die damit erzielten Ergebnisse bei 12 Patienten (6 Retinoblastome, 5 Aderhautmelanome, 1 Rhabdomyosarkom) werden dargestellt. Der Median der applizierten Dosis betrug in der Gruppe der Retinoblastome 35,5 Gy in 73 Stunden, bei den malignen Melanomen 56 Gy in 141 Stunden. Bei Retinoblastomen bzw. dem Rhabdomyosarkom wurde zusätzlich eine Chemotherapie gegeben.Ergebnisse:Die schlauchförmigen Applikatoren konnten problemlos um das zentrale Orbita-Implant eingesetzt werden. Durch Erhöhung der Aktivität im vorderen Abschnitt der Applikatoren ließ sich eine gute Dosisverteilung auch ohne zentralen Applikator erreichen. Es traten keine Rezidive und keine Wunddehiszenz mit Verlust des Orbita-Implants auf. Das kosmetische Ergebnis war in allen Fällen gut.Schlussfolgerung:Ein Orbita-Implant ergibt nach Enukleation ein ausgezeichnetes kosmetisches Resultat und sollte außer bei ausgedehntem Tumorbefall anderen Techniken vorgezogen werden. Die hier neu vorgestellte Technik erbringt auch ohne zentralen Applikator eine hervorragende lokale Kontrollrate und erspart dem Patienten die aufwendige und nicht immer erfolgreiche Entfernung und Wiedereinlage des Orbita-Implantats. Kurze Behandlungszeit und exzellente kosmetische Ergebnisse stellen einen weiteren Vorteil der Methode dar.

South Africa's cataract surgery rates: why are we not meeting our targets?

Cataract is the leading cause of blindness in South Africa, responsible for about 50% of the prevalence of blindness and identified as a national health priority. The cataract surgery rate (CSR) should be at least 2 000 per million population per year for elimination of cataract blindness. The national CSR target was planned to increase from 1 000 in 2005 to 2 000 in 2010, but since CSRs have failed to reach targets each year, the national target for 2010 was reduced from 2 000 to 1 500. We reviewed data from a situational analysis in 2007 of cataract surgery services to ascertain the obstacles to achieving CSR targets.

Identification of ocular surface squamous neoplasia by in vivo staining with methylene blue

Aim To evaluate the diagnostic accuracy of methylene blue used as a non-invasive in vivo stain to detect ocular surface squamous neoplasia (OSSN). Methods A test validation study was performed according to Standards for the reporting of diagnostic accuracy studies (STARD) guidelines on 75 consecutive patients who presented with ocular surface lesions suspicious of OSSN. Methylene blue 1% was instilled in vivo following local anaesthetic. Stain results were documented photographically and read by an independent observer. Lesions were excised at the same visit and evaluated histologically by pathologists who were blind to the stain results. Sensitivity, specificity, positive and negative predictive values were determined. Results Thirty-three patients had histologically malignant lesions, of which 32 stained with methylene blue, and 42 patients had benign or premalignant lesions, of which 21 stained with methylene blue. Methylene blue had a sensitivity of 97%, specificity of 50% and positive and negative predictive values of 60% and 96%, respectively. Conclusions The topical application of methylene blue is a simple, inexpensive, non-invasive diagnostic test that can be helpful in excluding malignant ocular surface lesions but cannot replace histology as gold standard for diagnosis of OSSN.

The treatment of carcinoma in situ and squamous cell carcinoma of the conjunctiva with fractionated strontium-90 radiation in a population with a high prevalence of HIV

Background This study explores the safety and efficacy of strontium 90 (Sr-90) brachytherapy as the sole adjuvant therapy for carcinoma in situ (CIS) and squamous cell carcinoma (SCC) of the conjunctiva in a high HIV prevalent area. Methods This is a retrospective case review of patients treated with 60 Gray Sr-90 brachytherapy in four divided doses after resection with a 2 mm margin and histological confirmation. Cryotherapy or alcohol debridement was not performed at the time of excision due to limited resources. Two plaque sizes, 8.5 mm and 18 mm, were used. Results Sixty-nine patients were treated and had a median follow-up of 27 months (range 6–127). Thirty-three (47.8%) were HIV-positive. CIS was present in 40.6% and SCC in 59.4%. The surgical margins were positive in 39 (56.5%). Twenty patients (29.0%) were treated with the 18 mm plaque and 49 (71.0%) with the 8.5 mm plaque. Eight (11.6%) patients developed a recurrence at a median of 5 months (range 2–40). Recurrences only occurred in patients treated with the 8.5 mm plaque (p=0.094). There was no significant effect of HIV status, positive margins or staging on the number of recurrences. Treatment side effects were a dry eye in five patients which was successfully managed with topical lubricants, and induced astigmatism of 1 dioptre of cylinder in one patient. Conclusions Sr-90 brachytherapy is safe and effective in preventing recurrences in ocular surface squamous neoplasia in a high HIV prevalent setting. The 18 mm plaque size is superior to the 8.5 mm plaque size.

Brachytherapy and endoresection for choroidal melanoma: a cohort study

Aim To report and compare the outcomes of brachytherapy and endoresection in the conservative treatment of medium sized choroidal melanoma. Methods A retrospective cohort study. Medium tumours were defined as 2.5–10 mm in height and less than 16 mm in the widest diameter. Consecutive patients undergoing brachytherapy at Groote Schuur Hospital were compared with a cohort undergoing endoresection from a national database. Results 148 brachytherapy and 22 endoresection patients were followed for a median of 55.4 and 62.4 months, respectively. Tumours undergoing endoresection were thicker (7.3 vs 4.9 mm, p<0.001, Wilcoxon rank-sum test) and further from the fovea (5.2 vs 3.7 mm, p=0.05, Wilcoxon rank-sum test) than those treated with brachytherapy. Visual acuity of 6/18 or better was maintained in 41% of the endoresection group and 35% of the brachytherapy group. The likelihood of achieving a final visual acuity of better than 2/60 was 22% higher in the endoresection group (risk ratio 1.22, 95% CI 1.02 to 1.28, p=0.034). Rates of local recurrence (18.2% vs 14.9%, p=0.75) and metastases or death (18.2% vs 14.2%, p=0.75) were higher in the endoresection group, and the enucleation rate was lower in this group (4.6% vs 10.8%, p=0.70) but these were not statistically significant. Conclusions The outcomes observed in this small cohort of endoresection patients suggest that endoresection of selected tumours may achieve better visual outcomes than brachytherapy. Rates of local recurrence, enucleation and metastases following endoresection require further research. Local recurrence is likely to be influenced by consolidation treatment methods.

Patterns of Uveitis at Two University-Based Referral Centres in Cape Town, South Africa

ABSTRACT Purpose: To analyze the pattern of uveitis at two tertiary hospitals in South Africa which has a high prevalence of HIV, TB and syphilis. Methods: Data of 198 patients were obtained retrospectively between August 2014 and August 2016, including patient demographics, clinical examination, special investigations and final diagnosis. Results: Infectious uveitis was the most common aetiological category (47%), followed by idiopathic (34.8%) and non-infectious (18.2%). Syphilis was the most common identifiable cause (16.2%). Other important causes were toxoplasmosis, herpes viruses, tuberculosis and HLA-B27. HIV positive patients, who constituted 40% of the study population, were more likely to present with a posterior or panuveitis (relative risk 1.50, 95% CI 1.19–1.89) and more likely to have an infectious cause compared to HIV negative patients (relative risk 2.47, 95% CI 1.82–3.35). Conclusions: This study emphasizes the importance of HIV testing and investigations for infectious causes of uveitis, especially syphilis, in this population.