paediatrics Brussels 17

I. J. Radiation Oncology ● Biology ● Physics

1342

Volume 58, Number 5, 2004

Table 3. Five-year overall survival and progression-free survival rates for all patients ( p values are two-tailed according to log–rank test)

%PFS (95% CI)

%OS (95% CI)

n

p

p

Residual disease after surgery Absent

46 17 35 28 16 47 44 19 43 20 63

65 (49–82) 35 (10–61) 64 (45–83) 46 (25–68) 76 (52–99) 48 (30–65) 66 (50–82) 36 (11–60) 66 (50–83) 30 (5–55) 56 (41–70)

0.05

82 (69–97) 61 (36–86)

0.031

Present

Age

6 years 6 years

0.07

85 (70–100) 64 (43–84) 84 (63–100) 71 (55–87) 78 (62–94) 68 (45–91) 87 (76–99) 40 (10–69) 75 (62–88)

0.02

Site

Supratentorial Infratentorial

0.08

0.24

Ventricular shunting No

0.05

0.08

Yes

Grading

Grade 2 Grade 3

0.0008

0.0001

Total

Abbreviations: PFS progression-free survival; OS overall survival.

reported by Vanuystel and Brada (18) , concluding that the risk of spinal seeding was uninfluenced by the extent of radiotherapy volume (local vs. craniospinal radiotherapy), we opted for local radiotherapy, which has become a stan- dard postoperative treatment in the majority of institutions (14, 19, 20) Hyperfractionated radiotherapy was adopted in the attempt to increase the chances of local tumor control in both treatment groups throughout the delivery of a higher total dose (70.4 Gy) as compared with conventional treat- ments (54–56 Gy), without increasing late damages on normal brain tissues. The preliminary results reported by Needle et al . on a monoinstitutional series of 19 patients

were indeed very favorable, with a PFS of 72% at 5 years after systemic chemotherapy and HFRT at a total dose of 72 Gy (21) . As for chemotherapy, the only randomized study pub- lished to date, which adopted vincristine and lomustine, concluded that this regimen did not improve survival (22) . Among other drug combinations, the “8 in 1” regimen, MOPP and etoposide-carboplatin, have been disappointing (3, 23) , whereas the best response rate so far has been reported by Duffner et al . with the Pediatric Oncology Group (POG) “baby brain” protocol (24) : The combination of vincristine plus cyclophosphamide, alternating with eto-

Fig. 3. Overall survival (OS) and progression-free survival (PFS) at 5 years for patients with Grade 2 and Grade 3 subtypes.