Long-Term Results and Prognostic Factors of Fractionated Strontium-90 Eye Applicator for Pterygium

• Published in: International journal of radiation oncology, biology, physics Vol. 72; no. 4; pp. 1174 - 1179
• Main Authors: Viani, Gustavo Arruda, M.D, Stefano, Eduardo Jose, M.D, De Fendi, Ligia Issa, M.D, Fonseca, Ellen Carrara, M.D
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.11.2008
• Subjects: 90Sr; Adjuvant treatment; Adult; Aged; Aged, 80 and over; Brazil - epidemiology; CATARACTS; Comorbidity; Dose Fractionation; EYES; Female; Hematology, Oncology and Palliative Medicine; Humans; Incidence; IRRADIATION; Long-term follow-up; Longitudinal Studies; Male; Middle Aged; MULTIVARIATE ANALYSIS; PATIENTS; Prognosis; Prognostic factors; Pterygium; Pterygium - epidemiology; Pterygium - radiotherapy; RADIATION DOSES; Radiation Injuries - epidemiology; Radiology; RADIOLOGY AND NUCLEAR MEDICINE; Radiopharmaceuticals - therapeutic use; RADIOTHERAPY; Results; Risk Assessment - methods; Risk Factors; STRONTIUM 90; Strontium Radioisotopes - therapeutic use; SURGERY; TOXICITY; Treatment Outcome; ULCERS; Brazil; Pterygium; Long-term follow-up; Results; Adjuvant treatment; Strontium-90; 90Sr; Prognostic factors
• ISSN: 0360-3016; 1879-355X
• DOI: 10.1016/j.ijrobp.2008.02.075

Purpose To evaluate the long-term safety, effectiveness, and prognostic factors of fractionated postoperative β-irradiation. Methods and Materials Between 1993 and 2005, 623 patients with 737 pterygium lesions were treated with a strontium-90 eye applicator after surgical excision. The median follow-up period was 60 months (range, 6.7–139.5). Of the 737 lesions, 644 were primary and 93 were recurrences after surgical removal alone. Fractionated radiotherapy (RT) to a total dose of 35 Gy in five to seven fractions was used. Results A total of 73 local pterygium recurrences (9.9%) were noted. Of the recurrent cases, 80% were noted within 3 years after treatment. The 5- and 10-year probability of local control was 90% and 88%, respectively. The multivariate analysis for all cases demonstrated that gender, age, total radiation dose, recurrent pterygia, and interval between surgery and RT affected the overall local control rate. Late toxicities that might have been associated with strontium-90 RT included scleromalacia (scleral thinning) in nine eyes, adhesion of the eyelids in eight, cataracts in six, and scleral ulcer in five eyes. Conclusion Fractionated strontium-90 RT to a total dose of approximately 35 Gy in five to seven fractions results in a similar local control rate as higher doses in other series, with an acceptable complication rate.