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.