Butch Magsombol

Fluorine-18-fluorodeoxyglucose PET/CT for the evaluation of suspected recurrent uterine leiomyosarcomas

Background Uterine leiomyosarcomas are rare and aggressive malignancies of the uterine corpus with high recurrence rates and poor prognoses. The current recommendation for detection of recurrent uterine leiomyosarcoma involves periodic physical examination and conventional imaging such as CT or MRI. The role of fluorine-18-fluorodeoxyglucose positron emission tomography with integrated computed tomography (FDG-PET/CT) in the detection of recurrent uterine leiomyosarcomas is not yet established. Purpose To evaluate the use of FDG-PET/CT as a single integrated modality for the evaluation of suspected recurrent uterine leiomyosarcomas. Material and Methods A retrospective study was performed on patients who underwent FDG-PET/CT scans for suspected recurrent uterine leiomyosarcoma. Only patients with follow-up data were included in the study. FDG-PET/CT was evaluated as a single integrated imaging modality. A positive lesion on FDG-PET/CT was defined as a focal abnormality detected on either the PET or CT components, or both. Results Sixteen consecutive patients over 5 years underwent FDG-PET/CT for suspected recurrent uterine leiomyosarcoma. Five patients were excluded due to incomplete follow-up data. The remaining 11 patients were aged 36–58 years (mean age 48). FDG-PET/CT had a sensitivity of 100% (95% CI 63–100) and specificity of 100% (95% CI 20–100) for the detection of recurrent uterine leiomyosarcomas. Sites of metastases include lungs, peritoneum, liver, pancreas and breast, of which lungs and peritoneum were the most common. Two (18%) patients had discordant findings: FDG-PET negative metastatic nodules in the breast and lung detected on the CT component. The maximum standardized uptake value (SUVmax) of metastatic lesions ranged from 2.0 to 16.0 (mean 7.6). Conclusion FDG-PET/CT as a single integrated modality may be a useful for the evaluation of suspected recurrent uterine leiomyosarcomas. FDG-PET negative discordant nodules detected on the CT component may represent metastases and should be followed up closely.

The potential of hybrid SPECT/CT fusion imaging to improve diagnostic accuracy in the scintigraphic quantitative functional assessment of suspected unilateral mandibular hyperactivity

BackgroundMandibular asymmetry is commonly caused by disproportionate mandibular growth due to unilateral condylar hyperactivity. The current standard for mandibular condyle bone scintigraphy uses single photon emission computed tomography (SPECT) imaging after intravenous administration of technetium-99m-labeled diphosphates. To our knowledge, the use of hybrid SPECT integrated with multidetector computed tomography (SPECT/CT) imaging in the scintigraphic quantitative functional assessment of mandibular condyle growth has not yet been described.Case reportA 22-year-old male with mandibular asymmetry due to suspected unilateral condylar hyperactivity underwent SPECT/CT imaging of the skull and facial bones after intravenous administration of technetium-99m methylene diphosphonate. Using CT to guide anatomical contouring, precise regions of interest were drawn over the mandibular condyles and clivus in adjacent SPECT/CT transaxial slices to calculate the mean radiotracer count ratios. For comparison of quantitative results, conventional SPECT images were obtained from the SPECT/CT data and processed according to conventional methods. Planar images were also obtained for visual assessment of mandibular condyle activity. All three methods, SPECT/CT, conventional SPECT, and planar imaging, found unilateral condylar hyperactivity of the left mandibular condyle. The condyles and clivus were easily and confidently identified on SPECT/CT images.DiscussionWe speculate that SPECT/CT imaging will improve the diagnostic accuracy of unilateral condylar hyperactivity. More studies are necessary to further define its role, obtain baseline reference values, and establish analysis protocols.

Intensely hypermetabolic extra-axial brainstem tumor in Erdheim-Chester disease.

Erdheim-Chester disease is a rare non-Langerhans cell histiocytosis characterized by progressive histiocytic proliferation with multiorgan involvement, typically of the kidney, skin, brain, and lung, and less frequently, the heart and retro-orbital tissue. Fluorine-18 fluorodeoxyglucose positron emission tomography (F-18 FDG PET) plays an important role in the management of this disease. It has been reported that FDG PET imaging allows accurate evaluation of the extent of the disease at baseline, as well as assessment of response to any specific therapy. In this case, a 57-year-old Chinese man presented with functional decline and a urinary tract infection. He had a prior history of xanthogranulomas of bilateral canthal masses. On imaging, he was found to have left hydronephrosis, diffuse urothelial thickening, increased density of the perinephric fat, mural thickening of the descending aorta and soft tissue masses along the posterior wall of the right atrium extending into the region of the interatrial septum and involving the right atrioventricular groove. Histopathology revealed retroperitoneal fibrosis. An IV contrast-enhanced FDG PET scan showed increased activity in a previously unidentified brain stem mass and the shafts of bilateral femora. Varying levels of FDG uptake were seen in the other lesions.

RETRACTED ARTICLE: A Case Series of Four Patients With Clinically Significant Radiomicrosphere Pneumonitis After Yttrium-90 Radioembolization from the Perspective of Lung Dosimetry

Dr. Yung Hsiang Kao, the first author and corresponding author, has retracted this case report due to honest error. The methodology used for this case report was unsuitable for the reporting of incidence rates and therefore does not accurately portray the disease incidence at the institution concerned.

Perinephric urinoma due to locally advanced recto-sigmoid tumor: incidental finding on bone scan.

We are presenting a 59 years old man with locally advanced recto-sigmoid colon cancer; complaining of left flank pain and bone scan was done to rule out bone metastases. Findings in bone scan were suggesting left renal obstruction, but further SPECT/CT imaging to localize the uptake revealed a perinephric collection likely due to leak from the left ureter close to tumor site.

Incidental detection of clinically nondiagnosed inguinal hernia in (131)I whole-body scan.

I whole-body bone scan was performed for an adult male patient after postradioactive iodine ablation of thyroid carcinoma. Besides the small thyroid remnants in the neck region, an incidental detection of left inguinal hernia was made in the scan, which was later confirmed by clinical examination. Despite the large size of the hernia, the patient was unaware of the condition. It can be concluded that, similar to other imaging procedures, incidental detection of unrelated clinical problems is possible in I scan also, and such early diagnosis prevents further complications that the patient may develop in the future.