A 34-year-old male patient was diagnosed with a left anterior meningeal hemangiopericytoma in 2016 and underwent surgical resection followed by adjuvant radiotherapy. Two years later, he developed a metastatic lesion at the D10 vertebra, which was treated with surgical decompression and postoperative radiotherapy. Recently, he presented with back pain at a tertiary care centre in Muscat, Oman, and underwent 68Ga-DOTATOC positron emission tomography/computed tomography (PET/CT) after a prior 18F-FDG PET/CT scan demonstrated low metabolic activity in the D10 vertebral lesion.
PET/CT imaging revealed an intensely 68Ga-DOTATOC-avid lesion at the D10 vertebra, with a maximum standardized uptake value (SUVmax) of 21.4. The corresponding CT images showed a soft tissue component encasing the prosthesis and extending into the spinal canal [Fig. 1]. Additionally, screw fixation from the D8 to D12 levels has resulted in beam-hardening artefacts at this site. The findings are consistent with tumour recurrence.
Fig. 1.
A&B: Present 68Ga-DOTATOC maximum intensity projection and transaxial PET/CT images, respectively, showing an intensely 68Ga-DOTATOC-avid lesion at the D10 vertebra with an SUVmax of 21.4 (arrow). The corresponding CT images reveal soft tissue components surrounding the prosthesis extending into the spinal canal. C: Sagittal PET/CT images demonstrating screw fixation from the D8 to D12 levels, which results in beam-hardening artefacts at this site (arrow). The SUV scale is used for reviewing and reporting PET images.
1. Comment
Hemangiopericytoma is a rare mesenchymal tumour originating from Zimmermann's pericytes, which surround capillaries and post-capillary venules.1 These tumours can arise in various locations, including the central nervous system, soft tissues and bones and have a high incidence of locoregional recurrence as well as distant metastasis, occurring in up to 50% of cases.2 Accurate diagnosis and staging are crucial for determining the appropriate treatment strategy and monitoring therapeutic response. Diagnosis and management rely on pathology and imaging modalities such as CT and magnetic resonance imaging (MRI). While MRI is essential for diagnosis and treatment planning, its accuracy may be compromised in patients with metallic implants due to artefacts and signal distortion. Moreover, MRI does not directly assess tumour metabolic activity, a key factor in treatment planning and prognosis. 3
Studies and clinical case reports indicate that hemangiopericytoma exhibit variable metabolic activity on 18F-FDG PET/CT, ranging from high to low uptake. In cases of low metabolic activity, 18F-FDG PET/CT may provide false-negative results, leading to underestimation of tumour burden.4 Somatostatin receptor scintigraphy using 68Ga-DOTA peptide PET is an established imaging modality for well-differentiated neuroendocrine tumours.5,6 Hemangiopericytomas are known to overexpress somatostatin receptors; however, the utility of 68Ga-DOTA peptide PET/CT in these tumours remains underexplored, particularly in cases with low 18F-FDG uptake.7 There is a paucity of studies, with only a few case reports demonstrating 68Ga-DOTA peptide uptake in these tumours.
This case highlights the potential of 68Ga-DOTATOC PET/CT in detecting hemangiopericytoma recurrence, especially when MRI accuracy is limited. This modality may aid in diagnosis, staging, treatment planning, and monitoring, potentially improving outcomes for these challenging vascular tumours. Additionally, it may serve as a gateway to potential 177Lu-DOTA peptide radionuclide therapy in cases with limited treatment options. Further research and clinical experience are required to fully elucidate the role of 68Ga-DOTATOC PET/CT in hemangiopericytoma management.
Authors' Contribution
Sharjeel Usmani: Conceptualization, Visualization, Writing – Original Draft, Writing – Review & Editing. Anjali Jain: Conceptualization, Writing – Review & Editing. Khulood Al Riyami: Investigation, Visualization. Syed Furqan Hashmi: Conceptualization, Writing – Original Draft, Writing – Review & Editing. Sofiullah Abubakar: Conceptualization, Visualization. Asiya Al Busaidi: Conceptualization, Visualization.
Ethics Statement
Written informed consent was obtained from the patient for publication of these images.
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