Intense Uptake Research Articles

Gallium 68-Fibroblast Activation Protein Inhibitor: PET/CT Improves Diagnosis of Neurocysticercosis

F18-FDG (Fluorine18- fluoro-deoxyglucose) Positron emission tomography/computerized tomography scan (PET/CT Scan) scan shows intense physiologic uptake in the brain parenchyma. This prevents evaluation of small cerebral lesions. Ga-68-FAPI (Gallium68- Fibroblast activation protein inhibitor) does not localize in normal brain parenchyma. Hence, it can detect cerebral lesions which concentrate the tracer. We report a case of neurocysticercosis in a 32 years old female who presented with headache, nausea and one episode of seizure. MRI brain raised possibility of tuberculoma over neurocysticercosis. There was a hypometabolic area in the right temporal lobe as revealed by F-18-FDG PET/CT, with no FDG avid lesions or lymph nodes identified in the body. Ga68-FAPI PET/CT was performed which showed increased tracer uptake within the right temporal lobe lesion. A focal FAPI uptake was also noted in a tiny hypodense lesion in the left internal oblique muscle of abdomen, which showed signal characteristics of intramuscular cysticercosis on limited MRI study.

Amphiphysin-IgG autoimmune sciatic neuropathy and facial neuropathy related to primary central nervous system lymphoma: A case report

We reported a 61-year-old man presented with 10-month progressing left sciatic neuropathy and 10-day right facial neuropathy. Serum amphiphysin-IgG was positive. 18F-FDG PET/CT of the whole body showed no signs of malignancy. Treatment with plasma exchange and oral prednisone relieved the symptoms. Nine months later, right hemiparesis and seizure of right limbs developed. 18F-FDG and 18F-PBR06 (18 kDa translocator protein, TSPO) radioligand PET/MRI of the whole body revealed intense uptake in the intracranial lesions. Intracranial lymphoma was diagnosed by stereotactic needle brain biopsy. Mononeuropathies could be paraneoplastic syndromes. TSPO shows high uptake in intracranial lymphoma on 18F-PBR06 PET images.

Primary Pancreatic Lymphoma Masquerading as Carcinoma on 18 F-FDG PET/CT.

A 76-year-old man with yellowish discoloration of sclera and skin for 2 months was referred to 18 F-FDG PET/CT for metabolic characterization of the mass in the pancreas. The images showed intense FDG uptake in the head of the pancreas, as well as a lymph nodal mass in the hepatic hilar region, which was consistent with pancreatic malignancy. Histopathologic findings showed characteristic findings of diffuse large B-cell lymphoma with no evidence of adenocarcinoma.

Preclinical Comparison of the 64Cu- and 68Ga-Labeled GRPR-Targeted Compounds RM2 and AMTG, as Well as First-in-Humans [68Ga]Ga-AMTG PET/CT.

Despite the recent success of prostate-specific membrane antigen (PSMA)-targeted compounds for theranostic use in prostate cancer (PCa), alternative options for the detection and treatment of PSMA-negative lesions are needed. We have recently developed a novel gastrin-releasing peptide receptor (GRPR) ligand with improved metabolic stability, which might improve diagnostic and therapeutic efficacy and could be valuable for PSMA-negative PCa patients. Our aim was to examine its suitability for theranostic use. We performed a comparative preclinical study on [64Cu]Cu-/[68Ga]Ga-AMTG ([64Cu]Cu-/[68Ga]Ga-α-Me-l-Trp8-RM2) using [64Cu]Cu-/[68Ga]Ga-RM2 ([64Cu]Cu-/[68Ga]Ga-DOTA-Pip5-Phe6-Gln7-Trp8-Ala9-Val10-Gly11-His12-Sta13-Leu14-NH2) as a reference compound and investigated [68Ga]Ga-AMTG in a proof-of-concept study in a PCa patient. Methods: Peptides were labeled with 64Cu (80 °C, 1.0 M NaOAc, pH 5.50) and 68Ga (90 °C, 0.25 M NaOAc, pH 4.50). GRPR affinity (half-maximal inhibitory concentration, room temperature, 2 h) and GRPR-mediated internalization (37 °C, 60 min) were examined on PC-3 cells. Biodistribution studies were performed at 1 h after injection in PC-3 tumor-bearing mice. For a first-in-humans application, 173 MBq of [68Ga]Ga-AMTG were administered intravenously and whole-body PET/CT scans were acquired at 75 min after injection. Results: 64Cu- and 68Ga-labeling proceeded almost quantitatively (>98%). All compounds revealed similarly high GRPR affinity (half-maximal inhibitory concentration, 1.5-4.0 nM) and high receptor-bound fractions (79%-84% of cell-associated activity). In vivo, high activity levels (percentage injected dose per gram) were found in the PC-3 tumor (14.1-15.1 %ID/g) and the pancreas (12.6-30.7 %ID/g), whereas further off-target accumulation was low at 1 h after injection, except for elevated liver uptake observed for both 64Cu-labeled compounds. Overall biodistribution profiles and tumor-to-background ratios were comparable but slightly enhanced for the 68Ga-labeled analogs in most organs. [68Ga]Ga-AMTG confirmed the favorable pharmacokinetics-as evident from preclinical studies-in a patient with metastasized castration-resistant PCa showing intense uptake in several lesions. Conclusion: AMTG is eligible for theranostic use, as labeling with 64Cu and 68Ga, as well as 177Lu (known from previous study), does not have a negative influence on its favorable biodistribution pattern. For this reason, further clinical evaluation is warranted.

The potential role of 68Ga-FAPI-04 PET/CT for screening malignancy in suspected colonic lesions.

Benign colonic lesions like tubular adenoma may show intense uptake on F-18-FDG PET/CT and can be mistaken for malignancy. In this study, we evaluated the role of 68Ga-FAPI-04 PET/CT for discriminating the benign and malignant colonic lesions. Forty patients with diagnosis of colorectal cancer who had undergone 18F-FDG-PET/CT and 68Ga-FAPI-04 PET/CT for initial staging were retrospectively analyzed. The unexpected foci of uptake in colon on 18F-FDG PET/CT were compared with 68Ga-FAPI-04 PET/CT with lesion and background SUVmax. The primary colorectal lesion SUVmax on both PET/CTs was similar. A total of 9 incidental colon lesions in 7 patients were detected showing intense 18F-FDG uptake and no 68Ga-FAPI-04 uptake. All of the lesions were consistent with tubular adenoma histopathologically. 68Ga-FAPI PET/CT may have a crucial role for discrimination of benign and malignant colonic lesions and avoid the unnecessary interventions and extended surgeries in patients with colorectal cancer.

Nasal-Type Extranodal Natural Killer/T-Cell Lymphoma Recurrence at Penile Glans Masquerading Urinary Contamination on 18F-FDG PET/CT.

A 69-year-old man with a history of extranodal NK/T-Cell lymphoma, nasal type (ENKTL-NT) performed an interim 18F-FDG PET/CT for response evaluation. It showed an intense focal uptake at his penile glans, which was suspected as urinary contamination initially. However, he complained with redness and swelling of his penis during further history inquiry. After careful observation, the diagnosis of ENKTL-NT recurrence at penile glans was highly suspected. It was confirmed by percutaneous biopsy of the penile glans finally.

PD-L1 Positron Emission Tomography Imaging in Patients With Non-Small Cell Lung Cancer: Preliminary Results of the ImmunoPET Phase 0 Study

ImmunoPET is a multicenter, single arm, phase 0-1 study of 89Zr-DFO-Sq-durvalumab (89Zr-durvalumab), a novel PET tracer, designed to interrogate the expression of PD-L1 in patients with NSCLC. Clinically relevant findings from phase 0 are presented here. Phase 0 was designed to investigate tracer biodistribution and safety in patients with metastatic NSCLC with PD-L1 expression >25%. After 60MBq/70kg 89Zr-durvalumab infusion, PET/CT images were acquired at days 0, 1, 3 or 5 ± 24h. Baseline FDG PET/CT was performed prior to PD-L1 PET imaging. All five patients recruited to phase 0 completed the full imaging protocol. The only reported adverse event was a transient asymptomatic increase in respiratory rate. At the time of PD-L1 imaging, two patients were in complete remission on FDG-PET after treatment with osimertinib and pembrolizumab; neither showed PD-L1 tracer uptake in previous tumor sites. All three patients with active tumor had received radiotherapy to some or all disease sites prior to PD-L1 imaging. With the exception of a single disease site, specific uptake of 89Zr-durvalumab uptake was seen in tumours, with increasing uptake in tumor seen up to Day 5 post-injection. Patient 1, who had multiple metastases, including brain and bone, showed more intense 89Zr-durvalumab uptake in recently irradiated bone lesions than un-irradiated lesions and uptake was also observed in treated brain metastases.. One patient, who experienced rapid growth of a single lung lesion that had acquired resistance to pembrolizumab, showed no significant 89Zr-durvalumab in that lesion, despite recent radiotherapy. In patient 5, 89Zr-durvalumab uptake was observed in the viable rim of a large, recently irradiated adrenal oligometastasis. 89Zr- durvalumab imaging was safe and detected known viable tumor at multiple sites. Recently irradiated tumours showed the highest uptake and in another, a single site of immunotherapy resistant disease showed minimal tracer uptake. PD-L1 imaging may have utility in patients with NSCLC treated with radiotherapy.

Intense Splenic 99m Tc-MDP Uptake in Patient with Langerhans Cell Histiocytosis

Intense Splenic 99m Tc-MDP Uptake in Patient with Langerhans Cell Histiocytosis

Intense Brown Fat Uptake at FDG PET/CT Induced by Mirabegron.

Intense Brown Fat Uptake at FDG PET/CT Induced by Mirabegron.

Cardiac Metastasis of Malignant Melanoma Detected by 18F-FDG PET/CT.

A 63-year-old man with a history of right plantar malignant melanoma (T3bN0M0, IIb) developed multiple metastases in bilateral lungs 19 months after surgery. Subsequent 18F-FDG PET/CT revealed multiple pulmonary metastases with intense FDG uptake and detected a hypermetabolic lesion in the lateral wall of the left ventricle, which was considered to be a cardiac metastasis of malignant melanoma. This lesion was later confirmed in the dynamic myocardial perfusion MR. This case demonstrates the effectiveness of 18F-FDG PET/CT in detecting occult cardiac metastases of malignant melanoma.

Next-generation PET/CT imaging in meningioma—first clinical experiences using the novel SSTR-targeting peptide [18F]SiTATE

BackgroundSomatostatin-receptor (SSTR)-targeted PET/CT provides important clinical information in addition to standard imaging in meningioma patients. [18F]SiTATE is a novel, 18F-labeled SSTR-targeting peptide with superior imaging properties according to preliminary data. We provide the first [18F]SiTATE PET/CT data of a large cohort of meningioma patients.MethodsPatients with known or suspected meningioma undergoing [18F]SiTATE PET/CT were included. Uptake intensity (SUV) of meningiomas, non-meningioma lesions, and healthy organs were assessed using a 50% isocontour volume of interest (VOI) or a spherical VOI, respectively. Also, trans-osseous extension on PET/CT was assessed.ResultsA total of 107 patients with 117 [18F]SiTATE PET/CT scans were included. Overall, 231 meningioma lesions and 61 non-meningioma lesions (e.g., post-therapeutic changes) were analyzed. Physiological uptake was lowest in healthy brain tissue, followed by bone marrow, parotid, and pituitary (SUVmean 0.06 ± 0.04 vs. 1.4 ± 0.9 vs. 1.6 ± 1.0 vs. 9.8 ± 4.6; p < 0.001). Meningiomas showed significantly higher uptake than non-meningioma lesions (SUVmax 11.6 ± 10.6 vs. 4.0 ± 3.3, p < 0.001). Meningiomas showed significantly higher uptake than non-meningioma lesions (SUVmax 11.6±10.6 vs. 4.0±3.3, p<0.001). 93/231 (40.3%) meningiomas showed partial trans-osseous extension and 34/231 (14.7%) predominant intra-osseous extension. 59/231 (25.6%) meningioma lesions found on PET/CT had not been reported on previous standard imaging.ConclusionThis is the first PET/CT study using an 18F-labeled SSTR-ligand in meningioma patients: [18F]SiTATE provides extraordinary contrast in meningioma compared to healthy tissue and non-meningioma lesions, which leads to a high detection rate of so far unknown meningioma sites and osseous involvement. Having in mind the advantageous logistic features of 18F-labeled compared to 68Ga-labeled compounds (e.g., longer half-life and large-badge production), [18F]SiTATE has the potential to foster a widespread use of SSTR-targeted imaging in neuro-oncology.

68Ga-FAPI-04 PET/CT in Selected Breast Cancer Patients With Low FDG Affinity: A Head-to-Head Comparative Study.

In this prospective study, PET findings of 18F-FDG PET/CT in breast cancer staging were compared with 68Ga-FAP inhibitor (FAPI) 04 PET/CT findings in selected cases with relatively low 18F-FDG uptake in the primary tumor or with suspected nodal or distant metastases. Twenty-four women with a median age of 45 years (range, 36-67 years) who underwent initial staging 18F-FDG PET/CT for breast cancer underwent 68Ga-FAPI-04 PET/CT imaging within the same week. SUVmax and quantities of primary tumors and locoregional and distant metastatic lesions were recorded from both images, and these data were compared statistically. The histological subtypes of primary tumors were 11 invasive lobular, 8 invasive ductal, and 5 mucinous subtypes. More intense 68Ga-FAPI-04 uptake (mean, 17.1 ± 7.9; 7.4-38.5) was detected in all primary tumoral lesions compared with 18F-FDG (mean, 6.3 ± 3.9; 1.5-20.5) (P = <0.001, Z = 4.107). Additional lesions showing 68Ga-FAPI-04 uptake in the breast were detected in 29.2% (n = 7) of patients. In 8.3% (n = 2) of the patients, the primary lesion showed only 68Ga-FAPI-04 uptake. In 68Ga-FAPI-04 PET/CT, 25% (n = 6) of the patients showed more lymph node involvement and more intense uptake in the ipsilateral axilla. In addition, infraclavicular (level 3) lymph nodes in 4 patients (16.7%), supraclavicular lymph nodes in 1 patient, and internal mammary lymph nodes in 1 patient were detected only on 68Ga-FAPI-04 PET/CT. In a patient with lung and bone metastases, 68Ga-FAPI-04 uptake was higher, and the lung nodule showed only 68Ga-FAPI-04 uptake. In selected low-FDG-affinity breast cancer patients, 68Ga-FAPI-04 PET/CT showed the primary tumor with higher sensitivity and higher SUVmax values compared with 18F-FDG PET/CT. In addition, it is believed that this method may contribute to the management of patients' treatment by increasing the nodal stage.

Bilateral Pulmonary Enteric Adenocarcinoma on FDG PET/CT.

Pulmonary enteric adenocarcinoma(PEAC) is a rare variant of pulmonary adenocarcinoma. We herein report FDG PET/CT findings of PEAC in a 76-year-old woman. The images showed widespread opacities in both lungs with intense FDG uptake. The pathology revealed pulmonary enteric adenocarcinoma.

Differentiating primary from secondary lung cancer with FDG PET/CT and extra-pulmonary tumor grade

ObjectiveAssess feasibility of differentiating primary from secondary lung cancer in patients with a solid solitary malignant pulmonary lesion (SMPL) and a previously resected extrapulmonary tumor. MethodsPatients with pathology proven primary or secondary lung cancer from a solitary pulmonary lesion and known histopathology of extrapulmonary tumor were included. Patients with a small pulmonary lesion size, multiple malignant pulmonary nodules or an active infectious/inflammatory process were excluded. Extrapulmonary tumor grade was categorized as low, intermediate and high and was matched to FDG uptake intensity of SMPL, with FDG uptake range (SMPL/Liver SUVmax) of <0.9 for low, 0.91–1.99 for intermediate and >2.0 for high extrapulmonary tumor grade. ResultsOf 274 patients, 62 met the study criteria. 46 are primary and 16 are secondary lung cancer. There are 19 low, 27 intermediate and 16 high grade extrapulmonary tumors. Mean SMPL SUVmax is 8.2 ± 4.5 and SMPL/liver SUVmax is 2.4 ± 1.4. There are 37 cases (60%) with mismatched results (e.g., low FDG SMPL with intermediate or high grade extrapulmonary tumor or vice versa) and 25 matched cases (40%) that are inconclusive (e.g., low FDG with low tumor grade or high FDG with high tumor grade). Of the mismatched cases, we correctly predicted 30 cases (81%) as primary lung cancers. ConclusionA mismatch between the SMPL SUVmax and the extrapulmonary tumor grade could be used to differentiate a primary lung cancer from a metastasis with reasonable accuracy. Our preliminary results support the hypothesis that FDG uptake intensity of a metastatic pulmonary lesion mirrors the tumor aggressiveness of its extrapulmonary neoplasm of origin.

Potential utility of SPECT/CT with 99mTc-Tektrotyd for imaging of post-myocardial infarction inflammation.

There is a need to develop methods for post-myocardial infarction (MI) inflammation monitoring. Scintigraphy with somatostatin receptor targeted radiotracers has potential in this field. The purpose was to study the association of 99mTc-Tektrotyd uptake intensity in MI area with heart contractility indices over 6-month follow-up. Fourteen patients with acute ST-segment elevation anterior MI (STEMI) were examined with 99mTc-Tektrotyd SPECT/CT, myocardial perfusion scintigraphy (MPS) at rest, cardiac magnetic resonance imaging (cMRI) and transthoracic echocardiography (TTE). Scintigraphic results were compared with 6-month TTE indices. On the 7th day after a MI onset, cardiac 99mTc-Tektrotyd uptake was found in 7 of 14 patients. Median of 99mTc-Tektrotyd SUVmax was 1.59 (1.38; 2.83), the summed rest score (SRS) was 11 (5; 18), infarct size (by cMRI)-13.15 (3.3; 32.2) %. 99mTc-Tektrotyd SUVmax strongly correlated with 6-month heart contractility indices (r=0.81, P<0.05 for the end diastolic volume; r=0.61 P<0.05 for Δ end diastolic volume), with SRS (r=0.85, P<0.05) and infarct size (by cMRI) (r=0.79, P<0.05). The intensity (SUVmax) of 99mTc-Tektrotyd uptake in the area of recent MI directly depends on the size of ischemic myocardial injury and correlates with changes of heart contractility indexes over the 6month follow-up.

Prostate-Specific Membrane Antigen Uptake Heterogeneity in Mixed Ductal-Acinar Adenocarcinoma of the Prostate.

Prostate-specific membrane antigen (PSMA) PET findings of mixed ductal-acinar adenocarcinoma of the prostate are rarely reported. We describe 18 F-PSMA-1007 PET/CT and delayed pelvic 18 F-PSMA-1007 PET/MRI findings in a case of prostatic mixed ductal-acinar adenocarcinoma with multiple lymph node and bone metastases. The primary tumor showed heterogeneous PSMA uptake. The metastases in the right ilium and acetabulum showed intense PSMA uptake, but the pelvic lymph node and left iliac bone metastases showed no significant PSMA uptake. Knowledge of the intraprimary and intermetastatic heterogeneity of PSMA uptake in mixed ductal-acinar adenocarcinoma of the prostate may be helpful for accurate interpretation.

Primary Extraskeletal Ewing Sarcoma of the Duodenum Revealed by 18 F-FDG PET/CT.

Extraskeletal Ewing sarcoma of the duodenum is a relatively uncommon entity tumor. We report a case of extraskeletal Ewing sarcoma in a 21-year-old woman. She complained of abdomen pain and melena. 18 F-FDG PET/CT showed an intense uptake by the duodenum mass along with multiple FDG-avid enlarged lymph nodes in the mesentery, which was pathologically proven as extraskeletal Ewing sarcoma.

18F-FDG PET and CT identifiers of high-risk lesions in the stomach and esophagus.

e16036 Background: Assessing the significance of incidentally found increased 18F-FDG uptake in the stomach and esophagus on PET/CT has long been a challenge. Currently, there is no clear guideline to assist clinicians with distinguishing malignant from benign uptake. This study aims to compare various PET and CT characteristics used separately and collectively, to identify high-risk foci of uptake. Methods: 18F-FDG PET/CT images from August 2018 to October 2022 were reviewed and patients who completed a follow up EGD due to incidentally found increased gastroesophageal uptake were included in this study. To identify high-risk foci, the following PET and CT characteristics were used: 1) uptake intensity, using lesion SUVmax relative to mediastinal blood pool and liver SUVmean values (≤ blood pool = 0, &gt; blood pool but &lt; liver = 1, ≥ liver = 2); 2) uptake pattern (diffuse = 0, segmental = 1, focal = 2); 3) eccentricity (circumferential= 0, eccentric = 1); and CT correlation score (normal = 0, thickening = 1, mass = 2). Cut-off values were determined using receiver operating characteristic (ROC) curves. Benign and malignant uptake were compared to histological findings using Pearson’s chi-square test. Results: Incidental uptake in the stomach and/or esophagus were noted in 473/7805 (6.1%) patients of which 89 (18.8%) had a follow up EGD and were included in this study. Uptake intensity did not differentiate benign and malignant as SUVmax was greater than background tissues in all cases (Score =2). Uptake pattern, eccentricity, and CT-correlation of PET were significantly different between benign and malignant foci ( p &lt; 0.001, p &lt; 0.001, and p &lt; 0.001, Chi-square). Using cut-off scores from ROC curves, the predictive value of different PET/CT characteristics in identifying high-risk foci was reviewed. Conclusions: PET eccentricity along with anatomic CT correlative findings, offer similar value in predicting high-risk uptake foci to uptake pattern, eccentricity, and CT correlation combined. These are both, however, superior to other PET/CT characteristics used alone or in combination. [Table: see text]

64Cu-SAR-bisPSMA (PROPELLER) positron emission tomography (PET) imaging in patients with confirmed prostate cancer.

5039 Background: Prostate cancer (PC) is the second most frequent malignancy in men globally. Prostate-specific membrane antigen (PSMA) is a type II transmembrane glycoprotein that is overexpressed in PC. Recently, several new 68Ga- and 18F-based PSMA-targeted PET agents have been approved by the FDA to detect PC, which offer improved sensitivity and specificity compared to traditional imaging. Methods: PROPELLER (NCT04839367) investigated 64Cu-SAR-bisPSMA in 30 men with untreated, histopathologically proven, primary PC with intermediate- to high-risk features. At screening, patients completed 68Ga-PSMA-11 PET/CT at 1h post dose. Following enrollment, patients received either 100MBq, 150MBq or 200MBq of 64Cu-SAR-bisPSMA, followed by PET/CT at 2-4h post dose. Safety was evaluated before and after 64Cu-SAR-bisPSMA dosing. The 68Ga-PSMA-11 and 64Cu-SAR-bisPSMA PET/CT scans were evaluated by 2 independent, blinded central readers for image quality, PC detection, and intensity of tracer uptake in lesions (SUVmax and Tumor-to-Background Ratio [TBR]). Results: A single, Grade 1 64Cu-SAR-bisPSMA-related AE was reported in the 200MBq cohort. Both readers scored 200MBq of 64Cu-SAR-bisPSMA as the dose providing the highest image quality. In this cohort, 64Cu-SAR-bisPSMA and 68Ga-PSMA-11 was able to detect primary PC in 100% and 77.8% of patients for Reader 1 and 85.7% and 83.3% of patients for Reader 2, respectively. In the 200MBq cohort, Reader 1 identified 41 lesions with 64Cu-SAR-bisPSMA vs 36 lesions with 68Ga-PSMA-11, while Reader 2 identified 31 lesions with 64Cu-SAR-bisPSMA vs 22 lesions with 68Ga-PSMA-11. In the 200MBq cohort, 64Cu-SAR-bisPSMA consistently showed higher uptake compared to 68Ga-PSMA-11 (SUVmax: Reader 1 median [IQR]: 31.40 [27.45] vs 10.08 [13.92], p &lt; 0.001, Reader 2 median [IQR]: 41.00 [46.09] vs 14.58 [14.98], p &lt; 0.001); TBR: Reader 1 median [IQR]: 49.07 [67.69] vs 21.91 [35.71], P = 0.0015), Reader 2 median [IQR]: 76.34 [66.37] vs 23.90 [33.05], p &lt; 0.001). Conclusions: 64Cu-SAR-bisPSMA was safe and effective for detecting PSMA-expressing lesions. 200 MBq of 64Cu-SAR-bisPSMA was determined as the optimal dose for future trials. 64Cu-SAR-bisPSMA PET/CT showed a greater number of lesions and lesions exhibited significantly higher uptake when compared to 68Ga-PSMA-11 in men being with intermediate- to high-risk PC. Further studies to evaluate 64Cu-SAR-bisPSMA as an imaging agent in patients with biochemical recurrence of PC are underway. Clinical trial information: NCT04839367 .

The role of MIBG scan in the diagnosis of pheochromocytoma.

e15064 Background: Pheochromocytoma is an uncommon adrenal medulla tumor. Metaiodobenzylguanidine (MIBG) scintigraphy is the current gold standard functional imaging method for evaluating pheochromocytoma, due to its excellent 100% specificity, 80% sensitivity, and general availability. In addition to establishing an extension evaluation and monitoring medication efficacy, MIBG scintigraphy is essential to confirm the diagnosis of suspected pheochromocytoma, especially when there is a tumor-like adrenal mass whose etiology is to be determined and biopsy is contraindicated given the risk of catecholamine discharge with hypertensive flare and the risk of bleeding. Our aims are to determine the efficacy of scintigraphy in the diagnosis of pheochromocytoma by examining the epidemiological characteristic and uptake patterns of the disease. Methods: In a retrospective analysis from January 2010 to December 2020, we examined pheochromocytoma patients medical records who had been referred for MIBG scintigraphy to the regional western Algerian Nuclear Medicine department at the University Hospital Center of Tlemcen. Prior to a progressive intravenous injection of 40–80 MBq of l-MIBG, patients underwent preparation (discontinuation of interfering drugs with I-MIBG especially antihypertensive treatment, thyroid blocking, and hydration). Imaging acquisition was carried out 48 and 72 hours later. Results: Fifty patients with probable pheochromocytoma (sex ratio = 0,78; mean age = 43 [17-74] years) completed I-MIBG scintigraphy prior to adrenalectomy. The MIBG scan has a high specificity and positive predictive value (100%). It confirms the presence of pheochromocytoma in 21 cases (42%), even if the metanephrine is normal in a patient with a non-secreting pheochromocytoma. In 18 cases, the main pattern is a single, homogenous, and intense intra-abdominal uptake. For the three remaining patients, a voluminous and heterogeneous uptake with a photopenic center that was associated to a necrotic adrenal mass larger than 10 cm in size, seen on abdominal Computerized Tomography (CT). In this retrospective analysis, no cases of metastatic or multiple diseases were documented. The sensitivity and negative predictive value are 84% and 86%, respectively. In 29 patients (58%), the scan reveals no abnormalities in uptake. This is attributed, in part, to 30% false positive biology (sampling conditions of urinary and/or plasmatic metanephrines and/or normetanephrines), 20% false positive CT imaging (differential diagnosis of adrenal mass: benign or malignant adrenal nodule), and 8% false negative MIBG scintigraphy (subcentimetric, cystic and necrotic lesion). Conclusions: Due to its exceptional specificity, robust sensitivity, and whole-body staging, MIBG scintigraphy—along with biology and morphology imaging—is a crucial noninvasive diagnostic method for the management of pheochromocytoma prior to adrenalectomy.