Vertebral body growth after craniospinal irradiation.
OBJECTIVE
To estimate the effects of radiotherapy and clinical factors on vertebral growth in patients with medulloblastoma and supratentorial primitive neuroectodermal tumors treated with craniospinal irradiation (CSI) and chemotherapy.


METHODS
The height of eight individual or grouped vertebral bodies (C3, C3-C4, T4, T4-T5, C6-T3, T4-T7, L3, L1-L5) was measured before and after CSI (23.4 or 36-39.6 Gy) in 61 patients. Of the 61 patients, 40 were boys and 21 were girls (median age, 7 years; range, 3-13 years), treated between October 1996 and October 2003. Sagittal T(1)-weighted magnetic resonance images were used for the craniocaudal measurements. The measurements numbered 275 (median, 5/patient; range, 3-7). The median follow-up after CSI was 44.1 months (range, 13.8-74.9 months).


RESULTS
Significant growth was observed in all measured vertebrae. Excluding C3-C4, the growth rate of the grouped vertebrae was affected by age, gender, and CSI dose (risk classification). The risk classification alone affected the growth rates of C3 (p = 0.002) and L3 (p = 0.02). Before CSI, the length of all vertebral bodies was an increasing function of age (p <0.0001). The C3 length before CSI was affected by gender and risk classification: C3 was longer for female (p = 0.07) and high-risk (p = 0.07) patients.


CONCLUSIONS
All vertebrae grew significantly after CSI, with the vertebrae of the boys and younger patients growing at a rate greater than that of their counterparts. The effect of age was similar across all vertebrae, and gender had the greatest effect on the growth of the lower cervical and upper thoracic vertebrae. The effect of the risk classification was greatest in the lumbar spine by a factor of < or = 10.
Hartley
Katherine A
KA
Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA.
Li
Chenghong
C
Laningham
Fred H
FH
Krasin
Matthew J
MJ
Xiong
Xiaoping
X
Merchant
Thomas E
TE
D000293:Adolescent; D000367:Age Factors; D002528:Cerebellar Neoplasms / Q000188:drug therapy / Q000532:radiotherapy*; D002574:Cervical Vertebrae / Q000033:anatomy & histology / Q000254:growth & development / Q000528:radiation effects; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000033:anatomy & histology / Q000254:growth & development / Q000528:radiation effects; D008297:Male; D008527:Medulloblastoma / Q000188:drug therapy / Q000532:radiotherapy*; D018242:Neuroectodermal Tumors, Primitive / Q000188:drug therapy / Q000532:radiotherapy*; D012189:Retrospective Studies; D018570:Risk Assessment; D012737:Sex Factors; D013131:Spine / Q000033:anatomy & histology / Q000254:growth & development / Q000528:radiation effects*; D013904:Thoracic Vertebrae / Q000033:anatomy & histology / Q000254:growth & development / Q000528:radiation effects