Therapeutic schedules influence the pattern of intellectual decline after irradiation of posterior fossa tumors.
BACKGROUND
To evaluate intellectual decline in children with posterior fossa (PF) tumors treated with different therapeutic protocols.


METHODS
Forty children had a complete neuropsychological evaluation prospectively twice, at least 6 months year (y) after the end of their treatment. Patients were classified into four groups according to treatment schedules: Group 1 (n = 7) PF radiotherapy (PFRT) alone at 50 Gy; Group 2 (n = 13) reduced-dose cranio-spinal irradiation (CSI) at 25 Gy with a PF boost; Group 3 (n = 9) standard CSI at 35 Gy and a PF boost; and Group 4 (n = 11) high-dose chemotherapy with stem cell support followed by PFRT at 50 Gy.


RESULTS
At the first evaluation (mean interval since diagnosis 3.7 y), the mean Full-Scale Intellectual Quotient (FSIQ) was 80 (SD = 19). Only patients in Group 1 had a normal mean IQ score of 92 (SD = 14). At the second evaluation (mean interval since diagnosis 6.3 y), the mean FSIQ scores were significantly lower with a mean difference of 2.4 points, i.e., a yearly decline of one point. The magnitude of the FSIQ decline was positively correlated with the first IQ score (P = 0.0001) and inversely correlated with age at diagnosis (P = 0.0005). A FSIQ decline was observed in all treatment groups except Group 1 (P = 0.005). The differences in FSIQ observed initially between the four treatment groups persisted at the second evaluation.


CONCLUSIONS
This study shows that FSIQ continues to decline more than 4 years after the diagnosis but this yearly decline seems to decrease with time from diagnosis. Therapeutic schedules influence the magnitude of this decline. Long-term follow-up into adulthood is necessary to effectively adapt patient rehabilitation.
Kieffer-Renaux
Virginie
V
Department of Pediatric and Adolescent Oncology, Institut Gustave Roussy, Villejuif, France.
Viguier
Delphine
D
Raquin
Marie-Anne
MA
Laurent-Vannier
Anne
A
Habrand
Jean-Louis
JL
Dellatolas
Georges
G
Kalifa
Chantal
C
Hartmann
Olivier
O
Grill
Jacques
J
D000293:Adolescent; D000328:Adult; D001071:Appointments and Schedules; D002648:Child; D002675:Child, Preschool; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D003131:Combined Modality Therapy; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D015192:Infratentorial Neoplasms / Q000150:complications* / Q000532:radiotherapy*; D007360:Intelligence / Q000528:radiation effects*; D007361:Intelligence Tests; D008297:Male; D011878:Radiotherapy / Q000009:adverse effects*; D013997:Time Factors