Patterns of local recurrence after intraoperative radiotherapy for advanced neuroblastoma.
OBJECTIVE
The purpose of this study was to retrospectively evaluate local recurrence patterns after intraoperative radiation therapy (IORT) combined with total or subtotal resection and intensive chemotherapy for advanced neuroblastoma.


METHODS
The outcomes of 27 patients (14 boys and 13 girls) with advanced-stage neuroblastoma who received IORT as part of multimodality therapy between November 1988 and December 2006 were reviewed in order to evaluate the impact of IORT. Of particular interest was the local recurrence patterns observed.


RESULTS
Six patients relapsed in the abdominal area: three out of six relapsed adjacent to the radiation fields. Other three relapsed in the field of electron ports. Among them, one relapsed in paraspinal lymph nodes, which are behind the irradiated volume but out of the reach of the electron beam, while another relapsed in the lymph nodes of the mesocolon, which had been displaced outside the irradiation field at the time of IORT. The last case relapsed beside the vertebral column near the left ureter, which had been shielded by a lead plate. These three 'in-field' recurrences would have been irradiated if external opposite two-beam radiations had been performed, instead of electron beams.


CONCLUSIONS
In spite of a complete tumor control in the treated volume, some 'marginal' recurrences were observed. Further investigation--for example, a combination of IORT and external-beam radiotherapy--should be considered to achieve higher local control and decrease complication rates.
Kunieda
Etsuo
E
Department of Radiology, Tokyo Metropolitan Kiyose Children's Hospital, Tokyo, Japan. kunieda-mi@umin.ac.jp
Hirobe
Seiichi
S
Kaneko
Takashi
T
Nagaoka
Tomoaki
T
Kamagata
Shoichiro
S
Nishimura
Gen
G
D000230:Adenocarcinoma / Q000175:diagnosis / Q000532:radiotherapy* / Q000601:surgery; D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000175:diagnosis / Q000532:radiotherapy* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007223:Infant; D007432:Intraoperative Period; D008279:Magnetic Resonance Imaging; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000209:etiology; D009367:Neoplasm Staging; D009447:Neuroblastoma / Q000175:diagnosis / Q000532:radiotherapy* / Q000601:surgery; D012186:Retroperitoneal Neoplasms / Q000175:diagnosis / Q000532:radiotherapy* / Q000601:surgery; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome