Salvage reirradiation for recurrent glioblastoma with radiosurgery: radiographic response and improved survival.
OBJECTIVE
To determine the radiographic and clinical efficacy of stereotactic single dose radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) as salvage therapy for glioblastoma (GBM) at recurrence.


METHODS
Thirty-six patients with pathologically proven recurrent GBM were treated with salvage reirradiation by either SRS or FSRT between March of 2001 and August of 2006. Thirty-one patients had an initial diagnosis of GBM. Five patients had a malignant transformation. All patients had received radiotherapy with a dose of 50-60 Gy, a median 13.6 months prior to reirradiation (range: 0.8-119 months). At the time of recurrence, 26 patients were treated with SRS with a median dose of 18 Gy (range: 12-20 Gy). FSRT was performed in ten patients with a dose of 36 Gy in six fractions, twice weekly. Follow-up included MRI and clinical examination every 2 months.


RESULTS
Median survival time after SRS was 8.5 months, compared to 7.4 months after FSRT (P = 0.81). Of 26 patients treated with SRS, radiographic tumor response or stable disease was observed in eight (35%) patients and tumor progression was seen in 18 (65%) patients. Of 10 patients treated by FSRT, radiographic tumor response or stable disease was observed in four (40%) patients and tumor progression was observed in four (40%) patients (two lost to follow-up). Patients who responded to treatment had statistically improved survival compared to non-responders, with median survival of 15.8 vs. 7.3 months (P < 0.05).


CONCLUSIONS
Salvage reirradiation with SRS or FSRT for recurrent GBM results in radiographic response in a proportion of patients. Survival was significantly improved among patients who either responded or had stable disease after salvage reirradiation, compared to non-responders. Further study is warranted to investigate the method and time of reirradiation for recurrent GBM.
Patel
Mehul
M
Henry Ford Health System, Detroit, MI, USA. mpatel2@hfhs.org
Siddiqui
Farzan
F
Jin
Jian-Yue
JY
Mikkelsen
Tom
T
Rosenblum
Mark
M
Movsas
Benjamin
B
Ryu
Samuel
S
D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000401:mortality / Q000601:surgery*; D005260:Female; D005909:Glioblastoma / Q000401:mortality / Q000601:surgery*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000601:surgery*; D016634:Radiosurgery / Q000379:methods*; D012189:Retrospective Studies; D016879:Salvage Therapy / Q000379:methods*