Asia Oceania Journal of Nuclear Medicine and Biology最新文献

We present a case of metastatic prostate cancer with rare metastases involving the brain and orbit, in addition to liver, skeletal and nodal metastases. The patient had undergone prior hormonal therapy and chemotherapy and had disease progression despite 2 cycles of ¹⁷⁷Lu-Prostate specific membrane antigen (¹⁷⁷Lu-PSMA) based radioligand therapy. He had a partial response after 2 cycles of ²²⁵Ac-PSMA based targeted alpha therapy, as demonstrated on the ⁶⁸Ga-PSMA PET/CT study. However, the patient had disease progression at the end of 4 cycles of ²²⁵Ac-PSMA therapy, evident by rising prostate specific antigen levels and imaging findings. The end of treatment ⁶⁸Ga-PSMA PET/CT showed additional sites of metastases in the orbit and brain apart from overall disease progression. These are rare sites of distant spread in prostate cancer and require urgent evaluation and local treatment to prevent potential complications. The importance of detection of metastatic sites in closed cavities is because of the requirement for urgent intervention to avoid compression related complications.

A 73-year-old man with lung cancer underwent bone scintigraphy for disease staging. Diffuse myocardial technetium hydroxymethylene diphosphonate (^99mTc-HMDP) uptake was incidentally found. A diagnosis of amyloid transthyretin (ATTR) cardiac amyloidosis was suspected, although the patient had no symptoms at this time. Single-photon emission computed tomography (SPECT) showed particularly strong uptake in the ventricular septum. Cardiac magnetic resonance imaging (CMR) showed widespread subendocardial and partly transmural enhancement of the left ventricular myocardium on delayed postcontrast T1-weighted images. These findings were consistent with ATTR cardiac amyloidosis. ¹⁸F-FDG uptake in the left ventricle wall was observed on PET/CT. He was finally diagnosed with ATTR by endomyocardial biopsy. There are two major subtypes of cardiac amyloidosis: ATTR amyloidosis and amyloid light-chain (AL) amyloidosis. Endomyocardial biopsy is the gold standard for diagnosis. Recently, however, several reports have shown that bone scintigraphy using a ^99mTc-labelled bone-seeking agent can detect ATTR cardiac amyloidosis and differentiate it from AL amyloidosis. Bone scintigraphy may play an important role in the detection and differentiation of ATTR cardiac amyloidosis.

Although ¹⁸F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) is an established method for the staging of malignancies, benign lesions (e.g, active inflammatory lesions) often show increased metabolic activity. Herpes zoster is the clinical manifestation of the activation and replication of dormant varicella-zoster virus (VZV) in individuals with decreased cell-mediated immunity. Although the diagnosis of herpes zoster is clinical, it is sometimes observed incidentally during imaging for another disease. We describe the case of a 67-year-old Japanese female patient diagnosed with cervical cancer in whom FDG-PET/CT revealed herpes zoster manifestations: hypermetabolic cutaneous lesions in the buttock and pelvic lymph node involvement. The resected lymph nodes showed no malignant lesions but revealed lymphoid follicle formation, probably related to viral infection. There has been no report comparing FDG-PET findings of lymph nodes with histologic findings; the present findings are compatible with a clinically VZV-induced inflammatory reaction in regional lymph nodes, which increased FDG accumulation. Active infection with VZV displays increased FDG uptake in regional lymph nodes and may lead to incorrect malignant disease management in oncology. Misdiagnoses can be avoided by a careful interpretation by experienced nuclear medicine physicians as well as proper clinical evaluation.

Objectives: ¹⁸F-Fluorodeoxyglucose (FDG) uptake in children is different from that in adults. Physiological accumulation is known to occur in growth plates, but the pattern of distribution has not been fully investigated. Our aim was to evaluate the metabolic activity of growth plates according to age and location.

Methods: We retrospectively evaluated 89 PET/CT scans in 63 pediatric patients (male : female=25 : 38, range, 0-18 years). Patients were classified into four age groups (Group A: 0-2 years, Group B: 3-9 years, Group C: 10-14 years and Group D: 15-18 years). The maximum standardized uptake value (SUV_max) of the proximal and distal growth plates of the humerus, the forearm bones and the femur were measured. The SUV_max of each site and each age group were compared and statistically analyzed. We also examined the correlations between age and SUV_max.

Results: As for the comparison of SUV_max in each location, the SUV_max was significantly higher in the distal femur than those in the other sites (p< 0.01). SUV_max in the distal humerus and the proximal forearm bones were significantly lower than those in the other sites (p< 0.01). In the distal femur, there was large variation in SUV_max, while in the distal humerus and the proximal forearm bones, there was small variation. As for the comparison of SUV_max in each age group, the SUV_max in group D tended to be lower than those in the other groups, but in the distal femur, there was no significant difference among each age group.

Conclusion: Our data indicate that FDG uptake in growth plates varies depending on the site and age with remarkable uptake especially in the distal femur.

Brain metabolic imaging using ¹⁸F-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) with contemporaneous low-dose CT may be used to assess neurodegenerative diseases. In contrast to oncology whole-body FDG PET, qualitative assessment alone in brain FDG PET is subjective and vulnerable to visual interference due to high physiologic background activity. Therefore, mild changes in brain metabolism may be visually undetectable by qualitative interpretation alone, resulting in diagnostic inaccuracy. To overcome this, some institutions may employ an objective comparison to a normal reference database. To date, there is limited literature describing brain metabolic changes in rare genetic neurodegenerative diseases such as Niemann-Pick disease Type C, spinocerebellar ataxia and Huntington disease. In this case series, we illustrate the typical FDG PET findings in the cortex and deep grey matter for these rare diseases, utilising normal database comparison including three dimensional Stereotactic Surface Projection (3D-SSP) mapping. These comparisons can generate 3D-SSP maps where metabolic changes may be expressed in standard deviations from normal (z-score) and visually depicted in a scale of colours to improve diagnostic accuracy.

A 65-year-old man presented with intermittent abdominal pain for three months. Abdominal ultrasonography revealed a mass in the body of the pancreas. Moreover, abdominal contrast-enhancing computed tomography revealed a homogenously enhancing mass in the body of the pancreas. Scan findings were in favor of the neuroendocrine tumor, and the serum chromogranin level was slightly raised (111.9 ng/ml, normal <98). He had no history of vomiting, jaundice, melena, hematemesis, constipation, diarrhea, weight gain, weight loss, loss of appetite, and fever. He also had no symptoms related to the excessive production of catecholamines, such as hypertension. The patient was referred for Ga-68 DOTANOC positron emission tomography-computed tomography (Ga-68 DOTANOC PET-CT) for further evaluation. The scan was done to rule out metastatic disease or other synchronous lesions to plan surgical excision. The Ga-68 DOTANOC PET-CT revealed a pancreatic lesion with no other abdominal lesions. We noted multiple tracer avid soft tissue lesions on both sides of the neck that were not diagnosed previously. This case report demonstrates a rare case with multiple paragangliomas diagnosed by the Ga-68 DOTANOC PET-CT. This finding could lead to changes in patient management.

Prostate cancer is considered to be the most common solid cancer affecting men worldwide and leading to a significant morbidity and mortality. Metastases are usually seen in bone or lymph nodes. For recurrent disease, PET imaging with ⁶⁸Ga-PSMA-11 (also known as HBED-CC, Glu-urea-Lys(Ahx)-HBED-CC, and PSMA-HBED-CC) is widely used. However, preparation of ⁶⁸Ga-PSMA ligand requires the presence of radiochemistry facilities and can therefore not be utilized in centers lacking such facilities. Recently, copper labeled prostate-specific membrane antigen positron emission tomography (⁶⁴Cu-PSMA PET/CT) demonstrated promising results in patients with recurrent disease and in the primary staging of selected patients with progressive local disease. In the present case, a rare manifestation site of a metastatic lesion in a patient with advanced prostate cancer is detected by ⁶⁴Cu-PSMA PET/CT.

High-grade B-cell lymphoma, an aggressive form of Non-Hodgkin's Lymphoma, is known as a double or triple hit lymphoma based on the presence of MYC and BCL2 without or with BCL6 genetic rearrangements, respectively. It carries a poorer prognosis, compared to other variants of B-cell lymphoma, and its management also differs which requires more intensive chemotherapy in contrast to the routine regimen. Terminal deoxynucleotidyl transferase (TdT), a marker of immaturity is commonly expressed in B-cell lymphoblastic leukemia or lymphoma (B cell ALL) which is absent in mature forms of B-cell lymphoma. The TdT is expressed in high-grade B-cell lymphoma; therefore, it poses a classification and management dilemma, which should be accurately differentiated from B-cell ALL and mandates molecular analysis. Herein, we report a case of a 52-year-old female with biopsy reported as high-grade B-cell lymphoma with TdT expression. She was referred for Fluor-deoxyglucose (FDG) Positron Emission Tomography-Computed Tomography (PET/CT) scan for staging in the absence of molecular analysis for B-cell ALL. It was diagnosed as lymphoma on FDG PET/CT based on its characteristic findings of extensive extranodal involvement of multiple organs with no significant lymphadenopathy establishing the incremental value of FDG PET/CT scan, which helped the clinician to arrive at a conclusion.

This quiz is part of a series which aims to aid nuclear physicians in interpreting the computed tomography (CT) component of the single photon emission computed tomography (SPECT) and positron emission tomography (PET) studies. The current quiz includes normal and pathological axial CT images at the level of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV). The SMV is normally located to the right of the SMA and is of a larger caliber. Various pathologies such as malignancy, infection or vascular disease can alter the position and/or appearance of the SMA, SMV and the surrounding anatomical structures present at this level. Understanding how normal anatomy is altered by pathology at this level will facilitate improved interpretation of abdominal CT images.

Objectives: Combined positron emission tomography/computed tomography (PET/CT) has gradually advanced with the introduction of newly developed techniques. However, the recent status of imaging techniques (e.g., scanning range, availability of correction methods, and decisions on performing delayed scan) in oncologic PET/CT with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) in Japan is unclear. We conducted a nationwide cross-sectional survey to document ¹⁸F-FDG PET/CT protocols and clarify the recent status of imaging techniques for oncologic ¹⁸F-FDG PET/CT in Japan.

Methods: We conducted a web survey hosted by the Japanese Society of Radiological Technology between October and December 2017. The questionnaire included nine items on the demographics of the respondents, their scan protocols, and additional imaging to their routine protocols.

Results: We received responses from 119 Japanese technologists who performed ¹⁸F-FDG PET/CT in practice. Almost all the respondents stated that the scanning range was from the top of the head to the pelvis or mid-thigh region. Newly developed techniques were used by fewer than half of the respondents. Most respondents performed additional imaging in consultation with physicians, such as delayed imaging (83%) or an extended scanning range for early imaging (55%).

Conclusions: Our survey helps in clarifying the recent state of oncologic ¹⁸F-FDG PET/CT imaging techniques in Japan. Given that ¹⁸F-FDG PET/CT practices most frequently performed additional imaging along with their routine scan protocol, the practice constitutes the most varied examination performed in Japanese nuclear medicine.