Generation and validation of a prognostic score to predict outcome after re-irradiation of recurrent glioma.
Re-irradiation using high-precision radiation techniques has been established within the clinical routine for patients with recurrent gliomas. In the present work, we developed a practical prognostic score to predict survival outcome after re-irradiation.


METHODS
Fractionated stereotactic radiotherapy (FSRT) was applied in 233 patients. Primary histology included glioblastoma (n = 89; 38%), WHO Grade III gliomas (n = 52; 22%) and low-grade glioma (n = 92; 40%). FSRT was applied with a median dose of 36 Gy in 2 Gy single fractions. We evaluated survival after re-irradiation as well as progression-free survival after re-irradiation; prognostic factors analyzed included age, tumor volume at re-irradiation, histology, time between initial radiotherapy and re-irradiation, age and Karnofsky Performance Score.


RESULTS
Median survival after FSRT was 8 months for glioblastoma, 20 months for anaplastic gliomas, and 24 months for recurrent low-grade patients. The strongest prognostic factors significantly impacting survival after re-irradiation were histology (p < 0.0001) and age (< 50 vs. ≥ 50, p < 0.0001) at diagnosis and the time between initial radiotherapy and re-irradiation ≤ 12 vs. > 12 months (p < 0.0001). We generated a four-class prognostic score to distinguish patients with excellent (0 points), good (1 point), moderate (2 points) and poor (3-4 points) survival after re-irradiation. The difference in outcome was highly significant (p < 0.0001).


CONCLUSIONS
We generated a practical prognostic score index based on three clinically relevant factors to predict the benefit of patients from re-irradiation. This score index can be helpful in patient counseling, and for the design of further clinical trials. However, individual treatment decisions may include other patient-related factors not directly influencing outcome.
University Hospital of Heidelberg, Department of Radiation Oncology, Heidelberg, Germany. Stephanie.combs@med.uni-heidelberg.de
Stephanie E
SE
Combs
Lutz
L
Edler
Renate
R
Rausch
Thomas
T
Welzel
Wolfgang
W
Wick
Jürgen
J
Debus
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001932:Brain Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D002648:Child; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005260:Female; D005909:Glioblastoma / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D005910:Glioma / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality* / Q000532:radiotherapy*; D011379:Prognosis; D019233:Retreatment; D061665:Time-to-Treatment; D055815:Young Adult