Case 1
A 22 years old male with no addictions or comorbidities, developed complaints of weakness in right sided upper limb and face, since January 2024. Magnetic resonance imaging (MRI) brain revealed a 5.3x4.5x4.1 cm well defined lesion with solid and cystic components in his left frontoparietal lobe, heterogenous enhancement of solid component and rim enhancement of cystic component, as shown in Figure 1 . MR spectroscopy showed elevated Choline, creatinine and reduced NAA peak. The differentials as per the report included pleomorphic xanthoastrocytoma and ganglioglioma. He underwent left frontoparietal craniotomy with near total tumour decompression in the 3rd week of February 2024, at a local hospital. MRI brain was not repeated in postoperative setting. The post-operative histopathological report (HPR) indicated high-grade and poorly differentiated malignant neoplasm with possibility of high-grade glioma or high-grade embryonic neoplasm.
He presented to the Department of Radiation Oncology in the second week of March 2024, three weeks after his surgery. He had no specific complaints. On examination, he was conscious, cooperative and well oriented to time, place and person. Glasgow coma scale pupil score (GCS-P) and Karnofsky performance score (KPS) were normal, 15 and 100 respectively. The neurological examination was within normal limits and there was no focal neurological deficit; including higher mental functions (mini-mental state examination score 26), motor-sensory systems, cranial nerve examination and absence of cerebellar signs. The slide and block review done at our centre showed a markedly cellular neoplasm arranged in sheets, as illustrated in Figure 2 . Small cells with hyperchromatic nuclei, inconspicuous nucleoli and scant cytoplasm were evident, indicating malignant round cell tumour, favouring Ewing sarcoma / peripheral neuroectodermal tumour. NKX2.2, synaptophysin and FLI1 were positive while GFAP and CD99 were negative as per the IHC report. At the radiotherapy planning MRI brain, minimal solid residual lesion was identified, pointing towards a subtotal resection, as shown in Figure 3 . Cerebrospinal fluid (CSF) was found to be negative for malignant cells, ruling out CSF dissemination. PET-CT confirmed the absence of any extracranial focus of hypermetabolism, ruling out extracranial primary with intracranial metastases, as shown in Figure 4 . EWSR1 gene rearrangement testing using FISH showed split signals and/or loss of green signals only in 6% tumour cell nuclei, so in view of absence of EWSR1 gene rearrangement, it was classified as Embryonal tumour as per World health organization (WHO) Central nervous system (CNS) Tumour classification 2021 and treatment was decided upon as per High-risk MB protocol. The patient was started on craniospinal irradiation (CSI) to the entire craniospinal axis to a dose of 36 Gy in 20 fractions, 1.8 Gy per fraction by 3-dimensional conformal RT (3DCRT) technique, followed by radiotherapy boost to residual disease and tumour bed to a dose of 18 Gray (Gy) in 10 daily fractions, 1.8 Gy per fraction by volumetric arc radiotherapy (VMAT), overall treatment time being 7 weeks. The 95% target volume dose coverage for the CSI and boost plan have been illustrated in Figure 5 . Blood counts were monitored weekly throughout CSI. He received concurrent vincristine during radiotherapy, however only two cycles were received in view of depleting blood counts . The adjuvant CTRT phase concluded in 1st week of June 2024. The patient was apparently alright at RT conclusion, with recovered blood counts. He has been planned for adjuvant chemotherapy as per six-weekly Packers A regimen, consisting of lomustine, cisplatin and vincristine.