Analysis Of Prognostic Factors Of Patients With Postoperative Gliomas After Fractionated Stereotactic Radiotherapy

Background and Objective: Glioma is the most common intracranialtumor, regarding 33.3％～58.9％(mean 43.5％) of all brain tumors in China. Thelong-term curative effect for most of the patients is still poor because of the glioma'sinvasive growth, which remains a challenge at present. Currently, the most popularmean of glioma's therapy is utmost resection of the tumor followed by postoperativeradiotherapy. It is difficult to achieve radical cure after this treatment, and its mediansurvival is still no more than one year. Fractionated stereotactic radiotherapy (FSRT)is a new radiotherapeutic technology and it can provide high dose of tumor, at thesame time protect the normal organs around tumor, therefore decrease the chance ofradiotherapeutic complications. Our hospital is one of the earliest hospital in Henanprovince using FSRT for gliomas. It is necessary to analyze these casesobjectively, evaluate the outcome after FSRT of patients with postoperative glioma interms of overall survival (OS), local control rate(LCR) and prognostic factors, inorder to find the factors affecting long-term survival of glioma patients and guideclinical treatment better.Materials and methods: Between October 1998 and December 2006, 82patients with histologically proven gliomas including 61 initial treatment patients and 21 recurrent patients, were treated with FSRT at our hospital. Of the 82 patients, therewere 37 with low-grade glioma(LGG, WHOⅠ,Ⅱ) and 45 with high-gradeglioma(HGG, WHOⅢ,Ⅳ). All patients included 69 patients with astrocytomas, 7patients with ependymoma and 6 patients with mesoglioma. In the initial treatmentgroup, except for 22 patients treated with FSRT alone, 39 patients were treated withFSRT for boost after conventional radiotherapy. In the recurrent group, all 21 patientswere previously treated with conventional radiotherapy or/and FSRT, with FSRTalone as salvage. The median volume of the target was 47.6cm~3 (2.7～97.6 cm~3). Themedian fractionated dose was 5.0Gy (range,4.0～8.0Gy). The median total dose was58.0Gy (range,28.8～89.5Gy).Results: With a median follow-up time of 40.3 months (range,3.5～92.7months). Of all the patients, CR11cases (13.4％), PR35cases (42.7％), NC21cases (25.6％), PD15cases (18.3％), local control rate (LCR) is 81.7％. LCR ofLGG group (100％) is higher than that of HGG group (66.7％), (P＜0.01). LCR ofgroup of FSRT target extension＞2cm(91.7％) is higher than that of FSRT targetextension≤2cm (73.9％), (P＜0.05). The: median survival time (MST) was 16.5months and the 1-, 2-, 3-, 5-year OS rates were 58.5％,45.1％,34.1％and 25.6％respectively for all patients. The MST was 57.6 months for LGG group comparedwith 9.4 months for the HGG group. There were significant differences in 1-, 2-, 3-,5- year OS rates between the two groups(100％,83.8％,59.5％,48.6％,vs. 24.4％,13.3％,13.3％,6.7％)(P＜0.01). In multivariate analysis, independently poorprognostic factors for overall survival were high-grade gliomas, more than 40 yearsold, KPS＜70, non complete resection. The rates of patients whose KPS≥70 beforeand after FSRT were 56.1％and 74.4％, (P＜0.05).Conclusion: 1. FSRT is effective in the treatment of initial and recurrentgliomas. 2. In multivariate analysis, independently poor prognostic factors for overallsurvival were high-grader gliomas, more than 40 years old, KPS＜70, non completeresection. 3. FSRT can significantly improve the living quality patients withpostoperative gliomas. 4. For patients with HGG, properly enlarging the FSTR target extension could increase the LCR, but could not benefit long-term survival.