Interstitial 125I radiosurgery of supratentorial de novo WHO grade 2 astrocytoma and oligoastrocytoma in adults : Long-term results and prognostic factors

• Published in: Cancer Vol. 106; no. 6; pp. 1372 - 1381
• Main Authors: KRETH, Friedrich W, FAIST, Michael, GRAU, Stefan, OSTERTAG, Christoph B
• Format: Journal Article
• Language: English
• Published: New York, NY Wiley-Liss 15-03-2006
• Subjects: Adolescent; Adult; Aged; Astrocytoma - classification; Astrocytoma - mortality; Astrocytoma - surgery; Biological and medical sciences; Cell Transformation, Neoplastic; Diseases of the nervous system; Female; Follow-Up Studies; Humans; Iodine Radioisotopes - therapeutic use; Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; Neoplasm Staging; Prognosis; Radiosurgery; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Retrospective Studies; Supratentorial Neoplasms - classification; Supratentorial Neoplasms - mortality; Supratentorial Neoplasms - surgery; Survival Rate; Tomography, X-Ray Computed; Treatment Outcome; Tumors; World Health Organization; Human; Nervous system diseases; Interstitial radiotherapy; 125I; Prognosis; Radiosurgery; prognostic factors; Radiotherapy; supratentorial; Long term; Intracranial tumor; De novo; Cerebral disorder; Cancerology; Treatment; Glioma; Central nervous system disease; WHO Grade 2 astrocytoma; Tumor; Adult; brachytherapy; Curietherapy; Astrocytoma; Low grade
• ISSN: 0008-543X; 1097-0142

Detailed long-term outcome data are not available for adult patients with World Health Organization (WHO) Grade 2 astrocytoma or oligoastrocytoma.
A previously published short-term data set of 239 adult patients with circumscribed de novo supratentorial astrocytoma (187 patients) and oligoastrocytoma (52 patients) treated with interstitial iodine-125 ((125)I) radiosurgery as primary treatment (1979-1992) was revisited. Survival, progression-free survival, functionally independent survival, postrecurrence survival, and time to malignant transformation were estimated with the Kaplan-Meier method. Prognostic factors were obtained from the Cox multivariate proportional hazards model.
Five-, 10-, and 15-year survival was 56%, 37%, and 26%, respectively (median follow-up, 10.3 yrs). Progression-free survival was 45%, 21%, and 14%, respectively. The corresponding malignant transformation rates were 33%, 54%, and 67%. No leveling off of the Kaplan-Meier curves could be observed for any of the chosen endpoints. Age > 50 years, a tumor volume > 20 mL, and/or a Karnofsky score < or = 80 were associated with decreased survival or progression-free survival. Age > 35 years and/or a tumor volume > 20 mL increased risk of malignant transformation. Prognostic factors determined subsets of patients with 10-year survival ranging from as low as 6% to as high as 55% and progression-free survival ranging 1-31%.
Long-term tumor stabilization is rare. As outcome is mainly determined by treatment-independent factors, minimization of any treatment-related risk must be considered essential.