24 results on '"Thakar, Alok"'
Search Results
2. Pterygoid Base Pneumatization Simulating Residual Disease-A Pitfall of Structural Imaging in Juvenile Nasal Angiofibroma.
- Author
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Sakthivel P, Thakar A, Verma H, Bhalla AS, Arunraj ST, and Kumar R
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- Edetic Acid, Humans, Magnetic Resonance Imaging, Male, Neoplasm Recurrence, Local, Positron Emission Tomography Computed Tomography, Angiofibroma diagnostic imaging, Nasopharyngeal Neoplasms, Prostatic Neoplasms
- Abstract
Abstract: As prostate-specific membrane antigen (PSMA) expression is universal in juvenile nasopharyngeal angiofibroma, it is commonly used for specifically differentiating recurrences from surgical site reparative tissues. Postoperative contrast-enhanced MRI revealed a residual disease in the left pterygoid base, but there was no PET/CT uptake with 68Ga-labeled PSMA at the same site. In retrospect, in comparison with preoperative PET/CT, it was found that the pterygoid base pneumatization was showing enhancement in contrast-enhanced MRI and not in functional PSMA. Postoperative 68Ga-PSMA PET/CT is a useful clinical tool in ambivalent diagnostic conditions avoiding morbidities., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
3. Fusion 68Ga-DOTANOC PET/MRI in Primary Juvenile Nasal Angiofibroma.
- Author
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Sakthivel P, Thakar A, Arunraj ST, Bhalla AS, Prashanth A, and Kumar R
- Subjects
- Adolescent, Angiofibroma pathology, Humans, Male, Nose Neoplasms pathology, Angiofibroma diagnostic imaging, Magnetic Resonance Imaging, Multimodal Imaging, Nose Neoplasms diagnostic imaging, Organometallic Compounds, Positron-Emission Tomography
- Abstract
Abstract: Somatostatin cell surface receptors are expressed in many different benign and malignant tumors and are often exploited for imaging and therapy of neuroendocrine tumors. A 17-year-old adolescent boy with clinicoradiologically diagnosed JNA (juvenile nasopharyngeal angiofibroma) also underwent 68Ga-DOTANOC PET to explore somatostatin cell surface receptors' expression and its theranostic potential. Fusion PET/MRI, a novel imaging technology, exactly depicted the anatomical extensions of the tumor with avid DOTANOC uptake. This software-based fusion technique is advantageous for easy early recurrence identification, better delineation from postoperative scar tissue, for planning the exact target volumes for stereotactic radiotherapy therapy of inoperable/residual/recurrent JNAs in the future., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
4. 68 Ga DOTANOC PET/CT Scan in Primary Juvenile Nasopharyngeal Angiofibroma - A Pilot Study.
- Author
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Sakthivel P, Kumar R, Arunraj ST, Bhalla AS, Prashanth A, Kumar R, Sharma SC, and Thakar A
- Subjects
- Adolescent, Angiofibroma pathology, Angiofibroma therapy, Antineoplastic Agents, Hormonal administration & dosage, Chemotherapy, Adjuvant methods, Child, Female, Flutamide administration & dosage, Humans, Male, Molecular Imaging methods, Nasopharyngeal Neoplasms pathology, Nasopharyngeal Neoplasms therapy, Nasopharynx diagnostic imaging, Nasopharynx pathology, Nasopharynx surgery, Neoadjuvant Therapy methods, Neoplasm Staging, Organometallic Compounds pharmacokinetics, Pilot Projects, Prospective Studies, Radiopharmaceuticals pharmacokinetics, Receptors, Somatostatin metabolism, Reproducibility of Results, Young Adult, Angiofibroma diagnosis, Nasopharyngeal Neoplasms diagnosis, Organometallic Compounds administration & dosage, Positron Emission Tomography Computed Tomography methods, Radiopharmaceuticals administration & dosage
- Abstract
Objectives/hypothesis: Somatostatin receptors (SSTRs) are highly expressed in neuroendocrine tumors and is exploited for its imaging and treatment. SSTRs expression is also demonstrated in diverse benign and malignant tumor cell types and proliferating peri-tumoral vessels. Similarly, Juvenile Nasopharyngeal Angiofibroma (JNA) expresses different SSTRs and may be utilized for its imaging and treatment using DOTA, 1-Nal3-octreotide (DOTANOC)-PET/CT scan., Study Design: Prospective cohort., Methods: Nineteen clinico-radiologically diagnosed primary JNA patients underwent a
68 Ga-DOTANOC PET-CT scan. Using a dedicated PET/CT scanner, a low-dose head and neck spot CT scan was performed after 45 to 60 minutes of intravenous injection of 2 to 3 mCi(74-111 MBq) of DOTANOC. The primary objective was to assess the intensity and pattern of DOTANOC uptake in these patients., Results: DOTANOC expression was noted in all cases (n = 19) of primary JNA (100%). The mean (SD) DOTANOC SUVmax ratio of tumor and background was 6.9+/-1.4(range, 3.8-9.5). Intra-cranial extension in all 13/19 patients was prominently visualized due to the absence of DOTANOC uptake in the brain. Compared to the background all stages of JNA showed significant DOTANOC uptake (P < .0001). No difference in uptake between advanced-stage tumors and early tumors was noted (P = .47). A statistically non-significant negative trend was noted for decreasing uptake with increasing age (Spearman correlation coefficient, r = -0.19)., Conclusions: This first study of68 Ga-DOTANOC-PET/CT scan in JNA demonstrates consistent and reliable uptake activity in all patients irrespective of age and stage. This opens up possibilities to physiological diagnostic imaging with a promise of greater specificity and sensitivity and may have applications in ambivalent diagnostic situations such as the detection of recurrence., Level of Evidence: 3 Laryngoscope, 131:1509-1515, 2021., (© 2020 The American Laryngological, Rhinological and Otological Society, Inc.)- Published
- 2021
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5. Validation of Postoperative Angiofibroma Radionuclide Imaging Study (PARIS) Protocol Using PSMA PET/CT-A Proof of Concept Study.
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Thakar A, Sakthivel P, Thankarajan Arunraj S, Bhalla AS, Prashanth A, Kumar R, Sharma SC, and Kumar R
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- Aged, Angiofibroma pathology, Angiofibroma surgery, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Nasopharyngeal Neoplasms pathology, Nasopharyngeal Neoplasms surgery, Postoperative Period, Proof of Concept Study, Prospective Studies, Angiofibroma diagnostic imaging, Angiofibroma metabolism, Antigens, Surface metabolism, Glutamate Carboxypeptidase II metabolism, Nasopharyngeal Neoplasms diagnostic imaging, Nasopharyngeal Neoplasms metabolism, Positron Emission Tomography Computed Tomography
- Abstract
Objectives: Juvenile nasopharyngeal angiofibroma (JNA) expresses prostate-specific membrane antigen (PSMA), and PSMA PET/CT scan may be used for its imaging. Also, the precise diagnosis of residual/recurrent JNA after surgical treatment remains difficult with conventional contrast MRI and/or CT; functional imaging with PSMA PET/CT promises greater accuracy in the detection or exclusion of recurrent/residual JNA., Patients and Methods: In this prospective study, 22 postoperative JNA patients who underwent a PSMA PET/CT scan both preoperatively and postoperatively from January 2018 to September 2020 were included. All patients underwent a low-dose head and neck spot PET/CT imaging. Abnormal postcontrast enhancement of a definite lesion was considered residual/recurrent tumor in contrast-enhanced MRI (CEMRI). In PSMA PET/CT, any abnormal uptake apart from physiological sites in the head and neck was considered as residual lesions. Radiological results were categorized as negative, suspicious for residual lesions, or definite residual/recurrent tumors. PSMA PET/CT findings were considered as the radiological standard, and patients were managed accordingly. The sensitivity, specificity, positive predictive value, and negative predictive value were separately calculated for CEMRI and PSMA PET/CT for diagnosing residual lesions., Results: On postoperative CEMRI evaluation, 12 patients had residual tumors, 2 had normal suspicious scans, and 8 had normal postoperative scans. On PSMA PET/CT, only 7 patients had residual tumors and 15 had normal postoperative scans. In 1 patient with a residual tumor on both scans, a discrepancy was noted concerning tumor extent, and PSMA PET/CT accurately mapped the tumor. The sensitivity, specificity, positive predictive value, and negative predictive value of CEMRI were 100%, 53.33%, 41.67%, and 100%, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of PSMA PET/CT were 100% for all parameters., Conclusions: Because CEMRI is oversensitive and less specific compared with PSMA PET/CT, Postoperative Angiofibroma Radionuclide Imaging Study (PARIS) protocol should be used always. In residual tumors, PSMA PET/CT has an outright advantage over CEMRI in the diagnosis, tumor mapping, decision making, planning stereotactic radiation, and aiding in future follow-ups., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2021
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6. Clinical utility of Ga68 DOTANOC PET/CT imaging in juvenile nasal angiofibroma and the PARIS protocol: a preliminary report.
- Author
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Thakar A, Sakthivel P, Arunraj ST, Bhalla AS, Prashanth A, Kumar R, Sharma SC, and Kumar R
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- Humans, Male, Adolescent, Child, Female, Nose Neoplasms diagnostic imaging, Prospective Studies, Young Adult, Angiofibroma diagnostic imaging, Positron Emission Tomography Computed Tomography, Organometallic Compounds
- Abstract
Objectives: Juvenile nasopharyngeal angiofibroma (JNA) expresses different somatostatin cell surface receptors and Ga68 [DOTA, 1-Nal3]-octreotide (DOTANOC)-PET/computed tomography (CT) scan may be used for its imaging. Also, functional imaging with DOTANOC-PET/CT may promise of greater accuracy in the detection or exclusion of recurrent/residual JNA., Methods: In this prospective study, five JNA patients who underwent a DOTANOC-PET-CT scan both preoperatively and postoperatively during June 2018-March 2020 were included. Postcontrast enhancement of a definite lesion was considered residual/recurrent tumor in contrast-enhanced MRI (CEMRI). In DOTANOC-PET/CT, any abnormal uptake apart from physiological sites was considered as residual lesions. Radiological results were categorized as negative, suspicious or definite residual/recurrent tumors. Any discrepancy was resolved by endoscopic biopsies., Results: Preoperatively all five cases of JNA showed avid DOTANOC expression in the tumor. The mean (SD) value of DOTANOC standardised uptake value in the tumor was 4.3 (1.4) (range = 2.1-6.2). In postoperative CEMRI evaluation, three of five patients had residual tumors and two had normal scans. On DOTANOC-PET/CT, two of five patients had residual tumors and three had normal scans. In one patient with residual tumor, the discrepancy with regard to tumor extent was noted in two scans, and further biopsy confirmed the findings of DOTANOC-PET/CT as accurate., Conclusion: 68Ga-DOTANOC-PET/CT uptake is universal in JNA and appears to be more specific in the identification of residual/recurrent JNA. In residual tumors, DOTANOC-PET/CT may have an advantage over CEMRI in the diagnosis, decision making and planning stereotactic radiation. However, these findings are to be validated in studies with larger patients., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2021
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7. Advantage of 68Ga-PSMA PET/CT on Postradiotherapy Response Assessment of Juvenile Nasal Angiofibroma.
- Author
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Sakthivel P, Thakar A, Thankarajan Arunraj S, Bhalla AS, and Kumar R
- Subjects
- Adolescent, Gallium Isotopes, Gallium Radioisotopes, Humans, Magnetic Resonance Imaging, Male, Treatment Outcome, Angiofibroma diagnostic imaging, Angiofibroma radiotherapy, Membrane Glycoproteins, Nose Neoplasms diagnostic imaging, Nose Neoplasms radiotherapy, Organometallic Compounds, Positron Emission Tomography Computed Tomography
- Abstract
Abstract: Prostate-specific membrane antigen (PSMA) is universally expressed in the endothelial cells of tumor-associated neovasculature of juvenile nasopharyngeal angiofibroma. Functional 68Ga-PSMA PET/CT also enables easier differentiation of the residual tumor from postoperative changes. An 18-year-old man with the residual intracranial disease received radiotherapy after surgery. In PSMA PET/CT imaging, uptake was noted initially only in the residual disease, and the same was absent after successful response to radiotherapy, unlike contrast MRI, which showed persistent enhancement. Functional 68Ga-PSMA PET/CT may be a very useful tool clinically for identifying early responses to radiotherapy compared with conventional structural imaging., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2021
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8. Plasma ablation-assisted endoscopic excision versus traditional technique of endoscopic excision of juvenile nasopharyngeal angiofibroma.
- Author
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Jaiswal AS, Kumar R, Thakar A, Kumar R, Verma H, Bhalla AS, Kairo AK, Kakkar A, Chandra Sharma S, and Sakthivel P
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- Endoscopy, Humans, Neoplasm Recurrence, Local surgery, Prospective Studies, Retrospective Studies, Angiofibroma surgery, Nasopharyngeal Neoplasms surgery
- Abstract
Background: Juvenile nasopharyngeal angiofibroma is the vascular and locally aggressive tumor of the posterior nares and nasopharynx. Endoscopic excision is the preferred surgical modality in early Radkowski stages. The prime challenge is intraoperative bleeding. Literature is in favor of the use of plasma ablation to overcome surgical challenges., Objective: To evaluate the effectiveness of plasma ablation technique in the surgical management of juvenile nasopharyngeal angiofibroma., Materials and Methods: The current study recruited 36 patients of clinico-radiologically diagnosed cases of primary JNA of stage I and II (Modified Radkowski). In prospective arm, 18 consecutive patients were recruited, who underwent plasma ablation assisted endoscopic excision. In retrospective arm, 18 consecutive patients who underwent excision by traditional endoscopic instruments in the past two years, were recruited. Both the groups were compared for baseline characteristics, intraoperative blood loss, duration of surgery, length of hospital stay, and recurrence rates., Results: The use of plasma ablation decreased overall blood loss by 338 ml (mean difference) which was not statistically significant (p = 0.26). On subgroup analysis, the use of plasma ablation significantly decreased mean blood loss (648 ml, p = 0.046) and duration of surgery (83 min, p < 0.001) in patients who underwent embolization. No statistically significant difference was noted between two groups in length of hospital stay (p = 0.36) and recurrence rates (p = 0.64)., Conclusion: Plasma ablation is an effective technique available to decrease blood loss and duration of surgery during endoscopic excision of post embolized stage I and II patients of JNA., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
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9. Comparison of Prostate-Specific Membrane Antigen PET/CT and Contrast-Enhanced Magnetic Resonance Imaging in Follow-up Assessment of Juvenile Nasal Angiofibroma-A Novel Pilot Study.
- Author
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Thakar A, Sakthivel P, Arunraj ST, Bhalla AS, Kakkar A, Kumar R, and Kumar R
- Subjects
- Aged, Angiofibroma pathology, Biopsy, Follow-Up Studies, Humans, Male, Middle Aged, Nose Neoplasms pathology, Pilot Projects, Prospective Studies, Angiofibroma diagnostic imaging, Antigens, Surface metabolism, Contrast Media, Glutamate Carboxypeptidase II metabolism, Magnetic Resonance Imaging, Nose Neoplasms diagnostic imaging, Positron Emission Tomography Computed Tomography
- Abstract
Purpose/background: The specific identification of residual/recurrent juvenile nasal angiofibroma (JNA) following surgical treatment remains difficult. Contrast MRI and CT may not enable the differentiation of tumor from postsurgical reparative tissue. Functional imaging with prostate-specific membrane antigen (PSMA) PET/CT targeting tumor-associated neovasculature has recently demonstrated universal positive uptake in primary JNA and offers promise of greater accuracy in the detection or exclusion of recurrent/residual JNA., Methods: In this prospective study, 18 postsurgical JNA patients with high suspicion for residual disease evinced by follow-up MR scan, or nasal endoscopy, or recent epistaxis during September 2018-November 2019 were included. All patients underwent head and neck spot PSMA PET/CT imaging. Postcontrast enhancement of a definite lesion was considered as a criterion for residual/recurrent tumor in contrast-enhanced MRI (CEMRI). In PSMA PET/CT, any abnormal uptake apart from physiological sites in the head and neck was considered as residual lesions. Radiological results were categorized as negative, suspicious, and residual/recurrent tumors. Any discrepancy between CEMRI and PSMA was resolved by surgical biopsies. The sensitivity, specificity, and positive and negative predictive values were separately calculated for CEMRI and PSMA PET/CT for diagnosing residual lesions. The interrater agreement κ value was also calculated., Results: On CEMRI evaluation, 14 of 18 patients had residual tumors, 2 had suspicious residual lesions, and 2 had normal postoperative scans. On PSMA PET/CT, 12 of 18 patients had residual tumors, and 6 had normal negative scans. Surgical biopsy in all 4 discordant cases was negative for tumors and revealed only fibrosis. In 1 patient with residual tumor on both scans, discrepancy was noted with regard to tumor extent demonstrated by the 2 scans, and further surgical excision confirmed the imaging findings of PSMA PET/CT as accurate. The sensitivity, specificity, and positive and negative predictive values of CEMRI were 100%, 33.33%, and 75% and 100%, respectively. The sensitivity, specificity, and positive and negative predictive values of PSMA PET/CT were 100% for all parameters. The interrater agreement between the 2 tests (κ) is 0.5 (95% confidence interval, 0.19-0.81)., Conclusions: The Ga-PSMA PET/CT is noted as more specific than the current standard of CEMRI in the identification of residual/recurrent JNA. It is the first radionuclide imaging scan that has found application in postoperative assessment of JNA., Trial Registration: Clinical Trials Registry of India (CTRI/2018/08/015479).
- Published
- 2020
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10. Fusion 68Ga-Prostate-Specific Membrane Antigen PET/MRI on Postoperative Surveillance of Juvenile Nasal Angiofibroma.
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Sakthivel P, Thakar A, Arunraj ST, Bhalla AS, and Kumar R
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- Aged, Angiofibroma pathology, Biopsy, Gallium Isotopes, Gallium Radioisotopes, Humans, Male, Multimodal Imaging, Nasopharyngeal Neoplasms pathology, Postoperative Period, Angiofibroma diagnostic imaging, Angiofibroma surgery, Magnetic Resonance Imaging, Membrane Glycoproteins, Nasopharyngeal Neoplasms diagnostic imaging, Nasopharyngeal Neoplasms surgery, Organometallic Compounds, Positron-Emission Tomography
- Abstract
Prostate-specific membrane antigen (PSMA) is expressed universally in juvenile nasopharyngeal angiofibroma (JNA). As contrast enhancement of postoperative scar is common with contrast-enhanced MRI (CEMRI), diagnosis of residual/recurrent JNA remains perplexing. Prostate-specific membrane antigen PET targets only the neovasculature and may aid in resolving this dilemma. Positive contrast enhancement on CEMRI was noted in a patient after 30 years of initial surgery, simulating recurrence. However, there was no abnormal uptake in PSMA scan, which was confirmed by biopsy as postoperative fibrosis. Ga-PSMA PET/MRI fusion may be an easy and novel technique to aid in differentiating residual/recurrent disease from surgical site reparative tissue.
- Published
- 2020
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11. Comparison of 68Ga-PSMA PET/CT and Contrast-Enhanced MRI on Residual Disease Assessment of Juvenile Nasal Angiofibroma.
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Thakar A, Sakthivel P, Prashanth A, Bhalla AS, Sharma SC, and Kumar R
- Subjects
- Adolescent, Gallium Isotopes, Gallium Radioisotopes, Humans, Male, Membrane Glycoproteins, Organometallic Compounds, Radiopharmaceuticals, Angiofibroma diagnostic imaging, Magnetic Resonance Imaging, Positron Emission Tomography Computed Tomography
- Abstract
Prostate-specific membrane antigen (PSMA) is expressed in the endothelial cells of tumor-associated neovasculature of various nonprostatic benign and malignant neoplasms including juvenile nasopharyngeal angiofibroma (JNA). Positive uptake on PET/CT imaging with Ga-labeled PSMA is noted in a patient with residual disease after initial surgery without any abnormal uptake in postoperative fibrosis, in contrast to contrast-enhanced MRI, which was confirmed by biopsy. Ga-PSMA PET/CT may be a useful tool clinically for identifying early biochemical recurrences and in specifically differentiating recurrences from surgical site reparative tissue.
- Published
- 2020
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12. Prostate-Specific Membrane Antigen Expression in Primary Juvenile Nasal Angiofibroma-A Pilot Study.
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Sakthivel P, Thakar A, Prashanth A, Bhalla AS, Kakkar A, Sikka K, Singh CA, Kumar R, Sharma SC, and Kumar R
- Subjects
- Adolescent, Angiofibroma metabolism, Antigens, Surface genetics, Child, Edetic Acid analogs & derivatives, Edetic Acid pharmacokinetics, Gallium Isotopes, Gallium Radioisotopes, Glutamate Carboxypeptidase II genetics, Humans, Nose Neoplasms metabolism, Oligopeptides pharmacokinetics, Radiopharmaceuticals pharmacokinetics, Young Adult, Angiofibroma diagnostic imaging, Antigens, Surface metabolism, Glutamate Carboxypeptidase II metabolism, Nose Neoplasms diagnostic imaging, Positron Emission Tomography Computed Tomography
- Abstract
Purpose: Prostate-specific membrane antigen (PSMA) is highly expressed in prostate cancer cells and is exploited for imaging and treatment of patients with prostate cancer. Prostate-specific membrane antigen expression is also demonstrated in the tumor-associated neovasculature endothelium. Juvenile nasal angiofibroma (JNA), being a similar highly vascular tumor, may also demonstrate significant PSMA expression, which may be utilized for its imaging and treatment., Methods: In this prospective study, 25 clinicoradiologically diagnosed primary JNA patients underwent PSMA PET/CT scan. The scan was performed after 45 to 60 minutes of intravenous injection of 2 to 3 mCi (74-111 MBq) of Ga-PSMA-HBED-CC on a dedicated PET/CT scanner. Low-dose CT scan was acquired from vertex to sternoclavicular joint (100 mA, 20 kVp, 3-mm slice thickness, 0.8 pitch). Images were reconstructed with iterative reconstruction technique (4 iterations, 24 subsets). The objective was to assess the intensity and pattern of PSMA uptake in primary JNA patients., Results: All cases (n = 25) of primary JNA showed PSMA expression in the tumor (100%). The median PSMA SUVmax ratio of tumor to background was 4.57 (range, 2.08-7.27). Intracranial extension in 14 of 25 patients was prominently visualized because of absence of background uptake in the brain. Advanced stage tumors demonstrated greater uptake than early tumors (P = 0.011). A statistically nonsignificant trend was noted for decreasing uptake with increasing age after normalizing for stage (Spearman correlation coefficient r = -0.08)., Conclusions: Assessment of PSMA expression in JNA by PSMA PET/CT opens up a new window of opportunity with respect to its radiological staging, vascularity assessment, and molecular characterization. A potential role in identification of the difficult residual-recurrent disease is anticipated and perhaps also in radioligand therapy for residual/recurrent JNA.Clinical Trials Registry of India (CTRI/2018/08/015479).
- Published
- 2020
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13. Clinical Utility of 68Ga-Prostate-Specific Membrane Antigen PET/CT Scan on Postoperative Assessment of Juvenile Nasal Angiofibroma.
- Author
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Thakar A, Sakthivel P, Prashanth A, Kumar R, Sharma SC, and Kumar R
- Subjects
- Adolescent, Angiofibroma pathology, Gallium Isotopes, Gallium Radioisotopes, Humans, Male, Nose Neoplasms pathology, Postoperative Period, Angiofibroma diagnostic imaging, Angiofibroma surgery, Membrane Glycoproteins, Nose Neoplasms diagnostic imaging, Nose Neoplasms surgery, Organometallic Compounds, Positron Emission Tomography Computed Tomography
- Abstract
Prostate-specific membrane antigen (PSMA) is expressed on the endothelial cells of tumor-associated neovasculature of various nonprostatic benign and malignant neoplasms. Positive uptake on PET/CT imaging with Ga-labeled PSMA is noted in a patient with juvenile nasal angiofibroma, and the same is noted to be absent following complete surgical excision. Ga-PSMA PET/CT may be a useful tool for juvenile nasal angiofibroma recurrence identification and in differentiating recurrence from surgical site reparative tissue.
- Published
- 2020
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14. Juvenile Nasal Angiofibroma on 68Ga-PSMA PET/CT: Opening New Frontiers.
- Author
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Sakthivel P, Prashanth A, Thakar A, Kumar R, and Kumar R
- Subjects
- Adolescent, Angiofibroma pathology, Angiofibroma therapy, Gallium Isotopes, Gallium Radioisotopes, Humans, Male, Neoplasm Staging, Nose Neoplasms pathology, Nose Neoplasms therapy, Angiofibroma diagnostic imaging, Edetic Acid analogs & derivatives, Nose Neoplasms diagnostic imaging, Oligopeptides, Positron Emission Tomography Computed Tomography
- Abstract
The prostate-specific membrane antigen (PSMA) is highly expressed in prostatic cancer. However, PSMA expression is also noted in various benign and malignant nonprostatic neoplasms in the endothelial cells of tumor-associated neovasculature. We performed Ga-PSMA PET/CT in a 14-year-old boy with juvenile nasal angiofibroma (JNA) to explore its theranostic potential. The scan revealed high uptake in the lesion. Performance of PSMA PET/CT in JNA opens up new frontiers with respect to radiological staging, early recurrence identification, and perhaps even radioligand therapy of residual/recurrent JNAs in the future.
- Published
- 2019
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15. Cerebrospinal Fluid Leak in Juvenile Nasopharyngeal Angiofibroma-Rare Sequelae of Flutamide-Induced Tumor Shrinkage.
- Author
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Panda S, Phalak M, Thakar A, and Dharanipathy S
- Subjects
- Adolescent, Angiofibroma diagnostic imaging, Angiofibroma surgery, Antineoplastic Agents, Hormonal adverse effects, Cerebrospinal Fluid Rhinorrhea diagnostic imaging, Cerebrospinal Fluid Rhinorrhea surgery, Flutamide adverse effects, Humans, Male, Meningitis complications, Meningitis drug therapy, Nasopharyngeal Neoplasms diagnostic imaging, Nasopharyngeal Neoplasms surgery, Tumor Burden, Angiofibroma drug therapy, Antineoplastic Agents, Hormonal therapeutic use, Cerebrospinal Fluid Rhinorrhea etiology, Flutamide therapeutic use, Nasopharyngeal Neoplasms drug therapy
- Abstract
Background: Nonsteroidal androgen receptor blockers like flutamide have been described as an adjuvant treatment for preoperative shrinkage of extensive juvenile nasopharyngeal angiofibroma. We present a case of cerebrospinal fluid (CSF) leak due to flutamide-induced tumor shrinkage., Case Report: A 15-year-old male with a prior diagnosis of juvenile nasopharyngeal angiofibroma stage IIIB on preoperative flutamide for 3.5 weeks presented with altered sensorium, meningeal signs, and clear watery nasal discharge consistent with CSF leak. Computed tomogram of the head revealed air in the ventricle and repeat contrast-enhanced magnetic resonance imaging showed significant tumor shrinkage in the area of the anterior skull base. This patient had an atypical pattern of tumor extension into the anterior skull base through the roof of posterior ethmoid and sphenoid sinus, which are inherently weak areas of the skull base, thereby predisposing the CSF leak on tumor shrinkage., Conclusion: CSF leak is a rare complication following flutamide therapy, especially if large areas of the anterior skull base are involved., (Copyright © 2018 Elsevier Inc. All rights reserved.)
- Published
- 2018
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16. Overt and occult vidian canal involvement in juvenile angiofibroma and its possible impact on recurrence.
- Author
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Thakar A, Hota A, Bhalla AS, Gupta SD, Sarkar C, and Kumar R
- Subjects
- Adolescent, Adult, Angiofibroma surgery, Child, Humans, Nasopharyngeal Neoplasms, Prospective Studies, Skull Base surgery, Young Adult, Angiofibroma pathology, Neoplasm Recurrence, Local pathology, Neoplasm, Residual pathology
- Abstract
Background: Postexcision residual disease in the vidian canal is speculated to contribute to recurrence in juvenile angiofibroma., Methods: We composed a prospective cohort of 16 consecutive patients with juvenile angiofibroma (stages IIA-IIIB). The presurgical vidian canal assessment was done by contrast-enhanced CT (1.2 mm collimation). At surgery after complete tumor excision, the vidian canal tissue was sampled for histology. Postexcision drilling of the vidian canal was done in 8 of 15 patients to remove microscopic residual disease, with a 24 to 48 month follow-up period., Results: Presurgical radiology indicated ipsilateral vidian canal enlargement (≥3 mm)/destruction in 13 of 16 patients. Radiologically occult involvement was documented only by histology in another 1 of 16 patients. Postexcision sampling of the vidian canal noted microscopic residual tumor in 3 of 15 patients. No recurrences were noted in 8 cases (0 of 8) with postexcision drilling of the vidian canal and 2 recurrences in 7 cases (2 of 7) with no drilling (p = .20)., Conclusion: Vidian canal involvement in juvenile angiofibroma is almost universal (14 of 16) and may be occult to CT evaluation. The site may harbor microscopic residual tumor after seemingly complete excision. Surgical attention toward it may reduce recurrences. © 2015 Wiley Periodicals, Inc. Head Neck 38: E421-425, 2016., (© 2015 Wiley Periodicals, Inc.)
- Published
- 2016
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17. Expression of vascular endothelial growth factor in Juvenile Angiofibroma.
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Hota A, Sarkar C, Gupta SD, Kumar R, Bhalla AS, and Thakar A
- Subjects
- Adolescent, Angiofibroma surgery, Blood Loss, Surgical, Child, Endothelial Cells metabolism, Humans, Immunohistochemistry, Male, Neoplasm Staging, Puberty, Retrospective Studies, Skull Base Neoplasms surgery, Stromal Cells metabolism, Angiofibroma metabolism, Angiofibroma pathology, Neoplasm Recurrence, Local metabolism, Skull Base Neoplasms metabolism, Skull Base Neoplasms pathology, Vascular Endothelial Growth Factor A metabolism
- Abstract
Objective: To examine Juvenile Angiofibroma (JA) tissue for expression of vascular endothelial growth factor (VEGF), and to explore its relationship with puberty status, stage, recurrence and the intraoperative blood loss., Methods: Retrospective cohort study of 36 histologically proven cases of JA. Minimum follow up period was 3 years. VEGF expression on tumor cells assessed by immunohistochemistry and graded on two criteria--percentage of cells expressing positivity and the intensity of positivity. These two parameters assessed for impact on puberty status, stage, recurrence, and blood loss., Results: VEGF expression noted on the tumor endothelial cells in 36/36, and on the tumor stromal cells in 34/36. The percentage of cells expressing VEGF and the intensity of expression were not significantly related to puberty status, tumor stage, recurrence, or intra-operative blood loss (p values 0.3-1.0)., Conclusion: VEGF expression is near universal in JA. Such expression is independent of puberty status and stage, and does not impact on intra operative blood loss and recurrence., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2015
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18. Adjuvant therapy with flutamide for presurgical volume reduction in juvenile nasopharyngeal angiofibroma.
- Author
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Thakar A, Gupta G, Bhalla AS, Jain V, Sharma SC, Sharma R, Bahadur S, and Deka RC
- Subjects
- Adolescent, Adult, Angiofibroma pathology, Angiofibroma surgery, Chemotherapy, Adjuvant, Child, Humans, Male, Nasopharyngeal Neoplasms pathology, Nasopharyngeal Neoplasms surgery, Tumor Burden drug effects, Young Adult, Androgen Antagonists administration & dosage, Angiofibroma drug therapy, Flutamide administration & dosage, Nasopharyngeal Neoplasms drug therapy
- Abstract
Background: Although 2 studies totaling 11 cases have indicated some benefit of anti-androgen treatment with flutamide on juvenile nasopharyngeal angiofibroma (JNA), it is not part of contemporary practice., Methods: Our approach was through a prospective, single-arm, before-and-after study, in which 20 patients with advanced JNA (Radkowski stage IIB-IIIB) were administered flutamide (per oral: 10 mg kg(-1) day(-1) × 6 weeks) prior to surgical excision. Pretherapy and posttherapy tumor volume measurements were established by MRI. Periodic assessments were recorded of liver, kidney functions, testosterone levels, and secondary sexual characteristics., Results: Prepubertal and postpubertal cases responded differently (p < .05). Prepubertal cases had inconsistent and minimal responses; 13/15 postpubertal cases demonstrated measurable volume reduction (mean, 16.5%; maximum, 40%). Two cases with optic nerve compression had visual improvement. Volume reduction correlated with serum testosterone level (r = .53; p < .05). No significant toxicity was noted, with the exception of transient breast tenderness., Conclusions: Prepubertal and postpubertal patients differ in their response to flutamide. In postpubertal patients, 6 weeks preoperative use is safe and leads to partial tumor regression. Tumor regression from adjacent vital structures may facilitate surgical excision and limit morbidity., (Copyright © 2011 Wiley Periodicals, Inc.)
- Published
- 2011
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19. Role of CD34-immunopositive Microvascular Density in Juvenile Nasopharyngeal Angiofibroma
- Author
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Jaiswal, Avinash Shekhar, Kumar, Rakesh, Kakkar, Aanchal, Kumar, Rajeev, Verma, Hitesh, Bhalla, Ashu Seith, Kairo, Arvind Kumar, and Thakar, Alok
- Published
- 2024
- Full Text
- View/download PDF
20. Clinical Applications of 68Ga-PSMA PET/CT on Residual Disease Assessment of Juvenile Nasopharyngeal Angiofibroma (JNA)
- Author
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Sakthivel, Pirabu, Thakar, Alok, Prashanth, Arun, Angamuthu, Meivel, Sharma, Suresh Chandra, and Kumar, Rakesh
- Published
- 2020
- Full Text
- View/download PDF
21. Juvenile Nasal Angiofibroma on
- Author
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Sakthivel, Pirabu, Thakar, Alok, Prashanth, Arun, Kumar, Rakesh, and Sharma, Suresh Chandra
- Subjects
juvenile nasopharyngeal angiofibroma ,DOTANOC positron emission tomography computed tomography ,Interesting Image ,Angiofibroma - Abstract
Somatostatin (SST) cell surface receptors (SSTRs) are expressed in many different malignant, benign, and neuroendocrine tumors. SSTRs are also expressed in the endothelium of human vessels during angiogenesis and not in the nonproliferating vessels. We present a case of 19-year-old boy with juvenile nasal angiofibroma (JNA), who underwent 68Ga-DOTANOC PET/CT to explore SSTRs expression and theranostic potential. The scan revealed high uptake in the tumor, and in certain areas, the uptake was similar to that of the pituitary gland. Performance of DOTANOC PET/CT in JNA opens up new frontiers with respect to radiological staging, early recurrence identification, better delineation from postoperative scar tissue, possible preoperative treatment with SST analogs, and perhaps even radiopharmaceutical based-ligand therapy of inoperable/residual/recurrent JNAs in the future.
- Published
- 2019
22. 68Ga DOTANOC PET/CT Scan in Primary Juvenile Nasopharyngeal Angiofibroma ‐ A Pilot Study.
- Author
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Sakthivel, Pirabu, Kumar, Rakesh, Arunraj, Sreedharan Thankarajan, Bhalla, Ashu Seith, Prashanth, Arun, Sharma, Suresh Chandra, and Thakar, Alok
- Abstract
Objectives/Hypothesis: Somatostatin receptors (SSTRs) are highly expressed in neuroendocrine tumors and is exploited for its imaging and treatment. SSTRs expression is also demonstrated in diverse benign and malignant tumor cell types and proliferating peri‐tumoral vessels. Similarly, Juvenile Nasopharyngeal Angiofibroma (JNA) expresses different SSTRs and may be utilized for its imaging and treatment using DOTA, 1‐Nal3‐octreotide (DOTANOC)‐PET/CT scan. Study Design: Prospective cohort. Methods: Nineteen clinico‐radiologically diagnosed primary JNA patients underwent a 68Ga‐DOTANOC PET‐CT scan. Using a dedicated PET/CT scanner, a low‐dose head and neck spot CT scan was performed after 45 to 60 minutes of intravenous injection of 2 to 3 mCi(74–111 MBq) of DOTANOC. The primary objective was to assess the intensity and pattern of DOTANOC uptake in these patients. Results: DOTANOC expression was noted in all cases (n = 19) of primary JNA (100%). The mean (SD) DOTANOC SUVmax ratio of tumor and background was 6.9+/−1.4(range, 3.8–9.5). Intra‐cranial extension in all 13/19 patients was prominently visualized due to the absence of DOTANOC uptake in the brain. Compared to the background all stages of JNA showed significant DOTANOC uptake (P <.0001). No difference in uptake between advanced‐stage tumors and early tumors was noted (P =.47). A statistically non‐significant negative trend was noted for decreasing uptake with increasing age (Spearman correlation coefficient, r = −0.19). Conclusions: This first study of 68Ga‐DOTANOC‐PET/CT scan in JNA demonstrates consistent and reliable uptake activity in all patients irrespective of age and stage. This opens up possibilities to physiological diagnostic imaging with a promise of greater specificity and sensitivity and may have applications in ambivalent diagnostic situations such as the detection of recurrence. Level of Evidence: 3 Laryngoscope, 131:1509–1515, 2021 [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
23. Clinical Utility of 68Ga-DOTANOC Positron Emission Tomography-Computed Tomography Scan on Postoperative Assessment of Juvenile Nasal Angiofibroma.
- Author
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Sakthivel, Pirabu, Thakar, Alok, Prashanth, Arun, Arunraj, Sreedharan Thankarajan, and Kumar, Rakesh
- Subjects
- *
POSITRON emission tomography computed tomography , *CELL receptors , *SURGICAL excision , *BENIGN tumors - Abstract
Somatostatin cell surface receptors are expressed on the peritumoral vessels of various benign and malignant neoplasms including angiofibromas. Positive initial uptake on positron emission tomography-computed tomography (PET/CT) imaging with 68Ga-labeled DOTANOC is noted in a patient with juvenile nasal angiofibroma (JNA), and the same is noted to be absent following complete surgical excision. Functional 68Ga-DOTANOC PET/CT may be an early useful tool for JNA residual/recurrence identification and precise postoperative surveillance. [ABSTRACT FROM AUTHOR]
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- 2020
- Full Text
- View/download PDF
24. Juvenile Nasal Angiofibroma on 68Ga-DOTANOC PET/CT: Exploring Theranostic Avenues.
- Author
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Sakthivel, Pirabu, Thakar, Alok, Prashanth, Arun, Kumar, Rakesh, and Chandra, Suresh Chandra
- Subjects
- *
CELL receptors , *PITUITARY gland , *SCARS , *NEUROENDOCRINE tumors , *POSITRON emission tomography computed tomography - Abstract
Somatostatin (SST) cell surface receptors (SSTRs) are expressed in many different malignant, benign, and neuroendocrine tumors. SSTRs are also expressed in the endothelium of human vessels during angiogenesis and not in the nonproliferating vessels. We present a case of 19-year-old boy with juvenile nasal angiofibroma (JNA), who underwent 68Ga-DOTANOC PET/CT to explore SSTRs expression and theranostic potential. The scan revealed high uptake in the tumor, and in certain areas, the uptake was similar to that of the pituitary gland. Performance of DOTANOC PET/CT in JNA opens up new frontiers with respect to radiological staging, early recurrence identification, better delineation from postoperative scar tissue, possible preoperative treatment with SST analogs, and perhaps even radiopharmaceutical based-ligand therapy of inoperable/residual/recurrent JNAs in the future. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
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