Radiation Oncology/CNS/Choroid Plexus

Epidemiology 0.5% intracranial neoplasms 10-20% intracranial neoplasms in <1 y/o 70% of choroid plexus tumors occur in pts <2 y/o Histology Choroid plexus papillomas are WHO grade I. Choroid plexus carcinomas are WHO grade III. 80% of choroid plexus tumurs are papillomas. Patterns of Spread Most common site is 4th ventricle. As high as 44% of choroid plexus carcinomas can have CSF seeding. CSF seeding rare for choroid plexus papilloma. Treatment Surgical Excision Johns Hopkins, 2002 (1985-2000) 12125972 -- "Is there a requirement for adjuvant therapy for choroid plexus carcinoma that has been completely resected?" (Fitzpatrick et al., J Neurooncol. 2002; 57(2):123-6.) 75 cases of choroid plexus carcinoma described in literature. 37 had GTR, 38 had STR 84% survival if GTR vs 18% if STR Long term survival was seen in pts who received GTR and no further tx; numbers were small. Adjuvant Radiotherapy Indications for adjuvant RT positive margins positive neuraxis staging WHO grade III Indications for CSI positive margins positive neuraxis staging Deferred Radiation in Young Children Baby POG I (1986-90) Prospective. 198 children < 3 yrs (132 < 2 yrs, 66 age 2-3 yrs), bx proven malignant brain tumors (low-grade astro excluded), treated with maximal surgery, postop chemo (CTX/VCR followed by cis/etopo) for 2 yrs (if age < 2 at dx) or 1 yr (age 2-3) or until disease progression, followed by RT. Histologies: 8 pts w/ choroid plexus tumors included in Baby POG I 1993 8388548 -- "Postoperative chemotherapy and delayed radiation in children less than three years of age with malignant brain tumors." (Duffner et al., N Engl J Med. 1993; 328(24):1725-31) CR to chemo PFS comparable those with GTR PFS 1995 7619719 -- "Postoperative chemotherapy and delayed radiation in infants and very young children with choroid plexus carcinomas. The Pediatric Oncology Group." (Duffner et al., Pediatr Neurosurg. 1995; 22(4):189-96.) 8 pts w/ choroid plexus carcinoma tx'd w/ surg, prolonged chemo, delayed RT. Results suggest this approach may allow prolonged DFS in young pts.