OTHR-10. Pilocytic astrocytoma with respect to treatment

AIM: To describe the sizes of pilocytic astrocytoma with respect to treatment Methodology Pediatric pilocytic astrocytomas cases from 2001 to 2021 were retrospectively reviewed in this Institutional Review Board approved study. Imaging reports, location of tumour, maximum dimension of tumour at diagnosis, treatment given (operation/chemotherapy/ radiotherapy), degree of tumor excision were captured. RESULTS: Imaging was available in 33 with 23 centered in the posterior fossa (1 extending into thalamus), 4 in suprasellar region, 2 in cerebral hemisphere, 2 in thalamus, 1 in pineal thalamic region and 1 in cervicomedullary spine, Tumor dimension at presentation was 5.40 cm ± 2.34 cm. Tumor size at presentation did not show significant correlation with age. 30 patients underwent operation with tumours completely excised in 15 and partially excised in 14 and no postoperative information for 1. Three patients, where tumour involved the thalamus, did not have operation and were given radiotherapy, average size of tumour being 3.47 + 1.15 cm. compared to the 5.59 + 2.34 size of tumours that underwent operation (p=0.06). Completely excised tumours measured 6.29 ± 2.04 cm at presentation while incompletely excised ones measured 4.76 ± 2.53 cm, not significantly different (p=0.09). Unoperated tumours are statistically smaller than those completely excised (p=0.02). One of the completetly excised tumours was located in the parietal cerebral hemisphere with the rest of the 15 in the posterior fossa. Seven of the incompletely excised tumours were located in the posterior fossa with 4 in suprasellar region, 1 in thalamus, 1 in spine and 1 in cerebral hemisphere. 3 patients with uncompletely excised tumours (1 cerebral, 1 post fossa, 1 spine) had post-operative radiation while 2 suprasellar tumours were given post-operative chemotherapy. CONCLUSION: Completely excised tumours are mainly located in posterior fossa. Tumours not operated on are located in thalamus and significantly smaller than tumours which are completely excised.