POSTOPERATIVE SURVEILLANCE IMAGING IN CHILDREN WITH CEREBELLAR ASTROCYTOMAS

The standard follow-up care for children with cerebellar astrocytomas includes regular surveillance imaging of the brain with computerized t omography or magnetic resonance. The purpose of surveillance imaging i s to detect asymptomatic tumor recurrence at an early stage and permit safer reoperation. The authors evaluated the effectiveness of an inte nsive surveillance program for cerebellar astrocytoma and tested diffe rent models of surveillance Frequency and duration to arrive at a spec ific recommended program. Review of the records of 93 children with ty pical cerebellar astrocytomas who received follow-up care between 1975 and 1993 was performed. Immediate postoperative and surveillance imag es were classified as showing definite, equivocal, or no turner based on the radiology report at the time the image was obtained. Various su rveillance models were then tested for their predictive value for dete cting tumor recurrence. Seventeen (18%) of the 93 children had tumor r ecurrence or progression. Eleven of these rumors were asymptomatic and detected only by surveillance image. Tumor recurred in only one patie nt with a total resection, whereas tumor progression occurred in five of 21 patients with equivocal postoperative images and in 11 of 14 pat ients with residual tumor. A model in which patients with possible or definite residual tumor after surgery undergo surveillance at 12, 18, 30, 42, and 66 months, and later have one additional image, yielded op timum predictive value for recurrence and/or progression with the fewe st images. Patients with tumor recurrence were satisfactorily treated, and only one patient died. Children with totally resected cerebellar astrocytomas do not appear to benefit from routine surveillance, becau se the likelihood of recurrence is small. Surveillance is of benefit i n those who may have subtotal resection based on the immediate postope rative imaging.