paediatrics Brussels 17

I. J. Radiation Oncology ● Biology ● Physics

956

Volume 42, Number 5, 1998

Table 4. The effect of tumor grade on patterns of failure

Low-grade (1–2) tumors ( n 5 70) Patterns of failure

Local failure

Local control

Total

Distant failure Distant control

3 (4%)

4 (6%)

7 (10%) 63 (90%) 70 (100%)

16 (23%) 19 (27%)

47 (67%) 51 (73%)

Total

High-grade (3–4) tumors ( n 5 10) Patterns of failure

Local failure

Local control

Total

Distant failure Distant control

3 (30%) 6 (60%) 9 (90%)

0

3 (30%) 7 (70%)

1 (10%) 1 (10%)

Total

10 (100%)

All patients ( n 5 80) Patterns of failure

Local failure

Local control

Total

Distant failure Distant control

6 (7.5%)

4 (5%)

10 (12.5%) 70 (87.5%) 80 (100%)

22 (27.5%) 28 (35%)

48 (60%) 52 (65%)

Total

Patients are categorized into various groups by tumor grade and the subsequent pattern of failure, including both local failures and distant (leptomeningeal) failures.

with survival. More extensive tumor resection was associ- ated with a non-significant trend favoring survival. The 5-year survival rates were 94% for patients having gross- total resections, 76% for those having subtotal resections, and 67% for those having only biopsies ( p 5 0.2). Univariate analysis (log-rank test) revealed that the fol- lowing factors were associated with survival: tumor grade, location, and histologic type. Patients with low-grade tu- mors had a 5-year survival rate of 87% as compared to 27% for those with high-grade tumors ( p , 0.0001) (Fig. 5). Patients with tumors of the spine had a 5-year survival rate of 97% as compared to 68% for those with lesions of the infratentorial brain and 62% for those with lesions of the supratentorial brain ( p 5 0.03) (Fig. 6). Patients with the myxopapillary subtype had a 5-year survival rate of 100% as compared to 76% for patients with other histological subtypes of ependymoma ( p 5 0.02) (Figs. 7 and 8). Mul- tivariate analysis revealed that survival was independently associated with both grade ( p 5 0.0007) and histological subtype ( p 5 0.02), but not tumor location ( p 5 0.07). DISCUSSION The present analysis was performed to define the long- term outcome of patients with ependymomas. The ideal

preoperative staging work-up should include a careful his- tory and physical examination, magnetic resonance imaging (MRI) of the clinically involved CNS site, and a CSF cytology. Clinically uninvolved CNS sites should also be imaged with MRI because of the risk of meningeal seeding. In our series, 6% of patients were found to have CNS seeding prior to therapy and 16% following treatment. Prognostic factors associated with survival on univariate analysis included tumor grade, location, and histologic type (myxopapillary vs. other subtypes). Both tumor grade and histologic type were associated with survival on multivari- ate analysis. The importance of tumor grade as a determi- nant of survival has been observed by other investigators (7–13). Tumor grade is the most consistently reported prog- nostic factor in the literature. Post-operative radiotherapy resulted in a high (87%) 5-year survival rate for those with low-grade tumors. Our data suggests that survival is improved when there is resec- tion of as much tumor as is safely possible. For patients having residual disease detected intraoperatively or with a postoperative MRI scan, moderate dose radiotherapy to the tumor bed is indicated. Garrett and Simpson reported a dose-response for patients with ependymomas. Of their patients who received # 45 Gy, 5 of 18 (28%) were alive at

Fig. 4. Overall survival for the entire group of patients.

Fig. 5. Overall survival by tumor grade (1 and 2 vs. 3 and 4).