Evaluation of five radiation schedules and prognostic factors for metastatic spinal cord compression.
OBJECTIVE
To study five radiotherapy (RT) schedules and potential prognostic factors for functional outcome in metastatic spinal cord compression (MSCC).


METHODS
One thousand three hundred four patients who were irradiated from January 1992 to December 2003 were included in this retrospective review. The schedules of 1 x 8 Gy in 1 day (n = 261), 5 x 4 Gy in 1 week (n = 279), 10 x 3 Gy in 2 weeks (n = 274), 15 x 2.5 Gy in 3 weeks (n = 233), and 20 x 2 Gy in 4 weeks (n = 257) were compared for motor function, ambulatory status, and in-field recurrences. The following potential prognostic factors were investigated: age, sex, performance status, histology, number of involved vertebra, interval from cancer diagnosis to MSCC, pretreatment ambulatory status, and time of developing motor deficits before RT. A multivariate analysis was performed with the ordered logit model.


RESULTS
Motor function improved in 26% (1 x 8 Gy), 28% (5 x 4 Gy), 27% (10 x 3 Gy), 31% (15 x 2.5 Gy), and 28% (20 x 2 Gy); and posttreatment ambulatory rates were 69%, 68%, 63%, 66%, and 74% (P = .578), respectively. On multivariate analysis, age, performance status, primary tumor, involved vertebra, interval from cancer diagnosis to MSCC, pretreatment ambulatory status, and time of developing motor deficits were significantly associated with functional outcome, whereas the RT schedule was not. Acute toxicity was mild, and late toxicity was not observed. In-field recurrence rates at 2 years were 24% (1 x 8 Gy), 26% (5 x 4 Gy), 14% (10 x 3 Gy), 9% (15 x 2.5 Gy), and 7% (20 x 2 Gy) (P < .001). Neither the difference between 1 x 8 Gy and 5 x 4 Gy (P = .44) nor between 10 x 3 Gy, 15 x 2.5 Gy, and 20 x 2 Gy (P = .71) was significant.


CONCLUSIONS
The five RT schedules provided similar functional outcome. The three more protracted schedules seemed to result in fewer in-field recurrences. To minimize treatment time, the following two schedules are recommended: 1 x 8 Gy for patients with poor predicted survival and 10 x 3 Gy for other patients. Results should be confirmed in a prospective randomized trial.
Rades
Dirk
D
Department of Radiation Oncology, University Hospital Hamburg, Martinistr. 52, D-20246 Hamburg, Germany. Rades.Dirk@gmx.net
Stalpers
Lukas J A
LJ
Veninga
Theo
T
Schulte
Rainer
R
Hoskin
Peter J
PJ
Obralic
Nermina
N
Bajrovic
Amira
A
Rudat
Volker
V
Schwarz
Rudolf
R
Hulshof
Maarten C
MC
Poortmans
Philip
P
Schild
Steven E
SE
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D018450:Disease Progression; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D011336:Probability; D011379:Prognosis; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects / Q000379:methods*; D020127:Recovery of Function; D012189:Retrospective Studies; D013117:Spinal Cord Compression / Q000209:etiology* / Q000401:mortality / Q000532:radiotherapy*; D013120:Spinal Cord Neoplasms / Q000150:complications / Q000401:mortality / Q000532:radiotherapy* / Q000556:secondary*; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome