Safety and Efficacy of 90Y Selective Internal Radiation Therapy Using Glass Microspheres in Hepatocellular Carcinoma: A Southeast Asian Single-Institution Initial Experience.

Our objective was to demonstrate primarily the safety and secondarily the efficacy of 90Y glass microspheres in selective internal radiation therapy (SIRT) for hepatocellular carcinoma (HCC) in a local Southeast Asian hospital. Methods: Eleven consecutive patients with small, unresectable, nonmetastatic HCC and referred for locoregional therapy with SIRT with a curative intention were followed up for 6 mo after the procedure by way of interviews, blood tests, and anatomic scans. Results: Although 5 patients had deranged liver function tests after the procedure, in only 1 patient did this constitute a grade 1 toxicity (in alkaline phosphatase) by the Common Terminology Criteria for Adverse Events. Half the patients showed a reduction in serum α-fetoprotein measurements, and 6 of 11 patients demonstrated an objective response (complete or partial) on imaging. Conclusion: SIRT with 90Y glass microspheres is a safe and efficacious locoregional therapy for unresectable HCC. There are similar articles published in the West; however, the patient population there comprises far fewer Asians and the underlying cause for HCC is different from that in the Asian population. Despite these differences, SIRT is an equally effective and safe option for such patients.

Personalized predictive lung dosimetry by technetium-99m macroaggregated albumin SPECT/CT for yttrium-90 radioembolization.

BACKGROUND: For yttrium-90 ((90)Y) radioembolization, the common practice of assuming a standard 1,000-g lung mass for predictive dosimetry is fundamentally incongruent with the modern philosophy of personalized medicine. We recently developed a technique of personalized predictive lung dosimetry using technetium-99m ((99m)Tc) macroaggregated albumin (MAA) single photon emission computed tomography with integrated CT (SPECT/CT) of the lung as part of our routine dosimetric protocol for (90)Y radioembolization. Its rationales are the technical superiority of SPECT/CT over planar scintigraphy, ease and convenience of lung auto-segmentation CT densitovolumetry, and dosimetric advantage of patient-specific lung parenchyma masses. METHODS: This is a retrospective study of our pulmonary clinical outcomes and comparison of lung dosimetric accuracy and precision by (99m)Tc MAA SPECT/CT versus conventional planar methodology. (90)Y resin microspheres (SIR-Spheres) were used for radioembolization. Diagnostic CT densitovolumetry was used as a reference for lung parenchyma mass. Pulmonary outcomes were based on follow-up diagnostic CT chest or X-ray. RESULTS: Thirty patients were analyzed. The mean lung parenchyma mass of our Southeast Asian cohort was 822 ± 103 g standard deviation (95% confidence interval 785 to 859 g). Patient-specific lung parenchyma mass estimation by CT densitovolumetry on (99m)Tc MAA SPECT/CT is accurate (bias -21.7 g) and moderately precise (95% limits of agreement -194.6 to +151.2 g). Lung mean radiation absorbed doses calculated by (99m)Tc MAA SPECT/CT and planar methodology are both accurate (bias <0.5 Gy), but (99m)Tc MAA SPECT/CT offers better precision over planar methodology (95% limits of agreement -1.76 to +2.40 Gy versus -3.48 to +3.31 Gy, respectively). None developed radiomicrosphere pneumonitis when treated up to a lung mean radiation absorbed dose of 18 Gy at a median follow-up of 4.4 months. CONCLUSIONS: Personalized predictive lung dosimetry by (99m)Tc MAA SPECT/CT is clinically feasible, safe, and more precise than conventional planar methodology for (90)Y radioembolization radiation planning.

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

BACKGROUND: Mandibular 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 REPORT: A 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. DISCUSSION: We 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.

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.