paediatrics Brussels 17

Conformal RT for Pediatric Ependymoma

Fig 1. Event-free survival estimates for patients treated with postoperative conformal radiation therapy.

Fig 2. Estimated mean intelligence quotient (IQ) before and after conformal radiation therapy.

P .0031), tumor grade (differentiated versus anaplastic; 90.3% 4.6% v 43.7% 12.4%; P .0001), and history of preirradiation chemotherapy (no chemotherapy v chemo- therapy, 78.1% 6.0% v 60.0% 14.3%; P .0446).There was no difference in PFS estimates between patients older than 3 years and those younger at the time of irradiation (80.8% 7.2% v 69.5% 8.6%; P .23) or between those with infratentorial tumors and those with supratentorial tumors (74.9% 6.3% v 71.4% 13.5%; P .86). PFS estimates were not influenced by the intervals between the time of symptom appearance and diagnosis, the interval between diagnosis and the start of CRT, and the number of elapsed treatment days. High tumor grade ( P .0001) and less than gross-total resection ( P .001) negatively affected outcome and the hazard ratio for PFS in a mul- tivariate analysis. Neurocognitive Effects The patients underwent a total of 316 neurocognitive examinations to evaluate changes in intelligence quotient (IQ), memory, academic achievement, adaptive behavior, and visual-auditory learning. There was no statistically sig- nificant change in the measures of these features for patients who completed evaluation 24 months after the initiation of CRT (more than half of the cohort; Figs 2 through 4). However, patients younger than 3 years at the time of CRT had a significantly lower mean IQ at the start of CRT than did patients older than 3 years (89.7 2.8 v 98.7 3.1; P .034), but the IQ of those younger than 3 years im- proved over time. There was no statistically significant dif- ference in IQ scores for patients comparing infratentorial and supratentorial tumor location. At the most recent follow-up, mean scores on all neurocognitive outcomes were within normal limits (ie, no more than 10 points from the normative mean for the appropriate age group).

ume reduces side effects without affecting the rate of tumor control or local pattern of failure. The results of this study demonstrated a 3-year PFS estimate of 74.7% 5.7% for patients with ependymoma treated with CRT using an an- atomically confined CTV whose 10-mm margin sur- rounded the postoperative tumor bed. The rate of failure in the study is less than those of other studies, which have yielded 2- to 5-year PFS estimates of only 50% to 67%. 25-30 Of the 20 patients who experienced recurrence or progression, none had marginal failures; however, the relatively large proportion of patients experiencing re- lapse with disease in the neuraxis but not at the primary site after treatment was both disappointing and informa- tive. This proportion was higher than the expected pro- portion, which is based on lower rates reported in some series, 31 and may indicate that the overall pattern of

DISCUSSION

Fig 3. Mean Wechsler Individual Achievement Test (WIAT) scores before and after conformal radiation therapy. CVLT-C, California Verbal Learning Test: Child; VAL, visual-auditory learning test.

The purpose of this study was to test the hypothesis that irradiation of a smaller-than-conventional treatment vol-

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