Patterns of failure in children with medulloblastoma treated with 3D conformal radiotherapy.
OBJECTIVE
Craniospinal irradiation for medulloblastoma is one of the most complex techniques employed in radiotherapy. Many reports stress the impact of irradiation quality on survival in these patients. Our report presents the outcome and patterns of failure for 95 patients treated with 3D conformal radiotherapy (3D-CRT).


METHODS
From 1998 to 2003, 95 children with medulloblastoma received 3D conformal radiotherapy. All of them were previously treated with surgery and chemotherapy. The brain and upper spinal cord were treated with two lateral 6MV photon fields. In four patients, the cribriform plate was irradiated by the additional field. For primary tumour bed we applied two or three photon beams. Spinal cord was irradiated either with 18-20MeV electron fields or with a mixed beam.


RESULTS
With a median follow-up of 48 months, 32/95 patients suffered a multifocal (21) or isolated (11) recurrence. We evaluated every primary site of failure. In all patients, the recurrence appeared within the isodose level of 95-100%.


CONCLUSIONS
Patterns of failure in medulloblastoma patients treated with 3D conformal radiotherapy indicated that the relapse was mainly associated with poor response to pre-irradiation chemotherapy. We believe that 3D conformal radiotherapy allows avoiding failures, related to radiotherapy uncertainties.
Skowrońska-Gardas
Anna
A
Department of Radiotherapy, M.Skłodowska-Curie Memorial Cancer Centre - Institute, Warsaw, Poland. agardas@coi.waw.pl
Chojnacka
Marzanna
M
Morawska-Kaczyńska
Marzena
M
Perek
Danuta
D
Perek-Polnik
Marta
M
D002528:Cerebellar Neoplasms / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery; D002648:Child; D016371:Cranial Irradiation; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008527:Medulloblastoma / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery; D009364:Neoplasm Recurrence, Local; D011829:Radiation Dosage; D018714:Radiotherapy, Adjuvant; D020266:Radiotherapy, Conformal; D016019:Survival Analysis; D017211:Treatment Failure