Utility of <Superscript>18</Superscript>F-fluoroestradiol (<Superscript>18</Superscript>F-FES) PET/CT imaging as a pharmacodynamic marker in patients with refractory estrogen receptor-positive solid tumors receiving Z-endoxifen therapy

Background

Z-endoxifen is the most potent of the metabolites of tamoxifen, and has the potential to be more effective than tamoxifen because it bypasses potential drug resistance mechanisms attributable to patient variability in the expression of the hepatic microsomal enzyme CYP2D6. ¹⁸F-FES is a positron emission tomography (PET) imaging agent which selectively binds to estrogen receptor alpha (ER-α) and has been used for non-invasive in vivo assessment of ER activity in tumors. This study utilizes ¹⁸F-FES PET imaging as a pharmacodynamic biomarker in patients with ER+ tumors treated with Z-endoxifen.

Methods

Fifteen patients were recruited from a parent therapeutic trial of Z-endoxifen and underwent imaging with ¹⁸F-FES PET at baseline. Eight had positive lesions on the baseline scan and underwent follow-up imaging with ¹⁸F-FES 1–5 days post administration of Z-endoxifen.

Results

Statistically significant changes (p?=?0.0078) in standard uptake value (SUV)-Max were observed between the baseline and follow-up scans as early as 1 day post drug administration.

Conclusion

F-FES PET imaging could serve as a pharmacodynamic biomarker for patients treated with ER-directed therapy.

     

Landing mechanics during single hop for distance in females following anterior cruciate ligament reconstruction compared to healthy controls

Purpose

To determine possible differences in single-hop kinematics and kinetics in females with anterior cruciate ligament reconstruction compared to healthy controls. A second purpose was to make comparisons between the healthy and reconstructed limbs.

Methods

Subjects were grouped based on surgical status (33 ACLR patients and 31 healthy controls). 3D motion capture synchronized with force plates was used to capture the landing phase of three successful trials of single hop for distance during a single data collection session. Peak values during the loading phase were analysed. Subjects additionally completed three successful trials of the triple hop for distance Tegner activity scale and International Knee Document Committee 2000 (IKDC).

Results

Controls demonstrated greater peak knee flexion and greater internal knee extension moment and hip extension moment than ACLR subjects. Within the ACLR group, the healthy limb exhibited greater peak knee flexion, hip flexion, hip extension moment, single hop and triple hops for distance and normalized quadriceps strength.

Conclusion

Patients who undergo anterior cruciate ligament reconstruction land in a more extended posture when compared to healthy controls and compared to their healthy limb.

Level of evidence

III.

     

Treatment-related features improve machine learning prediction of prognosis in soft tissue sarcoma patients

Background and purpose

Current prognostic models for soft tissue sarcoma (STS) patients are solely based on staging information. Treatment-related data have not been included to date. Including such information, however, could help to improve these models.

Materials and methods

A single-center retrospective cohort of 136 STS patients treated with radiotherapy (RT) was analyzed for patients’ characteristics, staging information, and treatment-related data. Therapeutic imaging studies and pathology reports of neoadjuvantly treated patients were analyzed for signs of response. Random forest machine learning-based models were used to predict patients’ death and disease progression at 2 years. Pre-treatment and treatment models were compared.

Results

The prognostic models achieved high performances. Using treatment features improved the overall performance for all three classification types: prediction of death, and of local and systemic progression (area under the receiver operatoring characteristic curve (AUC) of 0.87, 0.88, and 0.84, respectively). Overall, RT-related features, such as the planning target volume and total dose, had preeminent importance for prognostic performance. Therapy response features were selected for prediction of disease progression.

Conclusions

A machine learning-based prognostic model combining known prognostic factors with treatment- and response-related information showed high accuracy for individualized risk assessment. This model could be used for adjustments of follow-up procedures.

     

CAIPIRINHA accelerated SPACE enables 10-min isotropic 3D TSE MRI of the ankle for optimized visualization of curved and oblique ligaments and tendons

Objectives

To test the hypothesis that a fourfold CAIPIRINHA accelerated, 10-min, high-resolution, isotropic 3D TSE MRI prototype protocol of the ankle derives equal or better quality than a 20-min 2D TSE standard protocol.

Methods

Following internal review board approval and informed consent, 3-Tesla MRI of the ankle was obtained in 24 asymptomatic subjects including 10-min 3D CAIPIRINHA SPACE TSE prototype and 20-min 2D TSE standard protocols. Outcome variables included image quality and visibility of anatomical structures using 5-point Likert scales. Non-parametric statistical testing was used. P values ≤0.001 were considered significant.

Results

Edge sharpness, contrast resolution, uniformity, noise, fat suppression and magic angle effects were without statistical difference on 2D and 3D TSE images (p?>?0.035). Fluid was mildly brighter on intermediate-weighted 2D images (p?<?0.001), whereas 3D images had substantially less partial volume, chemical shift and no pulsatile-flow artifacts (p?<?0.001). Oblique and curved planar 3D images resulted in mildly-to-substantially improved visualization of joints, spring, bifurcate, syndesmotic, collateral and sinus tarsi ligaments, and tendons (p?<?0.001, respectively).

Conclusions

3D TSE MRI with CAIPIRINHA acceleration enables high-spatial resolution oblique and curved planar MRI of the ankle and visualization of ligaments, tendons and joints equally well or better than a more time-consuming anisotropic 2D TSE MRI.

Key Points

? High-resolution 3D TSE MRI improves visualization of ankle structures. ? Limitations of current 3D TSE MRI include long scan times. ? 3D CAIPIRINHA SPACE allows now a fourfold-accelerated data acquisition. ? 3D CAIPIRINHA SPACE enables high-spatial-resolution ankle MRI within 10 min. ? 10-min 3D CAIPIRINHA SPACE produces equal-or-better quality than 20-min 2D TSE.

     

Analysis of three ultrasound elastography techniques for grading liver fibrosis in patients with chronic hepatitis B

Background

Evaluation of liver fibrosis is important to assess prognosis and guide the treatment for chronic hepatitis B.

Objective

To analyze and compare transient, point, and two-dimensional (2D) shear wave elastography techniques in grading the liver fibrosis.

Methods

Based on the severity of liver inflammation and fibrosis (Scheuer criteria), 158 patients with chronic hepatitis B were assigned into group 1 (either G or S classification?<?2) or group 2 (either G or S classification?≥?2). Group 2 patients commonly require anti-viral treatment. All patients received transient (FibroScan), point (STQ), and 2D (STE) elastography examinations. Receiver operating characteristic curves were calculated from three elastography techniques in individual or in combination.

Results

A total of 158 patients were enrolled into the study, with 39.2% (62) female and mean age of 42.8 (standard deviation 19.1) years old. Transient elastography could not differentiate between group 1 and group 2 patients (P?=?0.12), whereas point and 2D elastography examinations could distinguish patients in group 1 from group 2 (P?<?0.01 for both STQ and STE). Administration of combined three elastography techniques showed the best diagnostic accuracy (90.1%) for liver fibrosis, which was confirmed with hepatic biopsy examination.

Conclusion

Point and 2D elastography were superior to transient elastography to detect liver fibrosis and guide clinical anti-viral treatment. Analysis of combined transient, point, and 2D elastography techniques showed the better diagnostic accuracy for liver fibrosis.

     

The incidence of radioepidermitis and the dose-response relationship in parotid gland cancer patients treated with 125I seed brachytherapy

Background

We studied the incidence and dose–response relationship of radioepidermitis in parotid gland carcinoma patients treated with [¹²⁵I] seed brachytherapy in the hopes of designing an optimized pre-implant treatment plan that would reduce the incidence and severity of radioepidermitis in patients receiving this therapy.

Patients and methods

Between January 2007 and May 2010, 100 parotid gland cancer patients were treated postoperatively with [¹²⁵I] seed brachytherapy. The matched peripheral dose (MPD) was 80–140 Gy, and [¹²⁵I] seed activity was 0.7–0.8 mCi. The mean dose delivered to the skin was calculated in the post-implant CT on day 0 following implantation. Grades of acute and late dermatitis were evaluated at 2, 6, 12, and 18 months post-implantation.

Results

Most patients experienced grade 0–2 acute and late skin side effects (86 and 97?%, respectively), though a small subset developed severe complications. Most grade 1–3 effects resolved within 6 months of implantation, though some grade 1–3 effects and all grade 4 effects remained unchanged throughout the 18-month follow-up period. Grade 3 and 4 effects were most prominent (75 and 25?%, respectively) with doses of 110–140 Gy; doses higher than 140 Gy produced only grade 4 effects.

Conclusion

[¹²⁵I] seed brachytherapy produced acceptable levels of acute and late radioepidermitis with a good clinical outcome. A mean dose under 100 Gy delivered to the skin was safe, though doses of 110–140 Gy should be given with caution and extra monitoring; doses greater than 140 Gy are dangerous and likely to produce grade 4–5 effects.

     

A Single Intraperitoneal Injection of Endotoxin Changes Glial Cells in Rats as Revealed by Positron Emission Tomography Using [<Superscript>11</Superscript>C]PK11195

Purpose

Intracranial administration of lipopolysaccharide (LPS) is known to elicit a rapid innate immune response, activate glial cells in the brain, and induce depression-like behavior. However, no study has focused on the changes in glial cells induced by intraperitoneal injection of LPS in vivo.

Methods

Ten adult male Fischer F344 rats underwent [¹¹C]PK11195 PET before and 2 days after intraperitoneal injection of LPS to evaluate the changes in glial cells. The difference in standardized uptake values (SUV) of [¹¹C]PK11195 between before and after injection was determined.

Results

There was a cluster of brain regions that showed significant reductions in SUV. This cluster included the bilateral striata and bilateral frontal regions, especially the somatosensory areas.

Conclusions

Changes in activity of glial cells induced by the intraperitoneal injection of LPS were detected in vivo by [¹¹C]PK11195 PET. Intraperitoneal injection of LPS is known to induce depression, and further studies with [¹¹C]PK11195 PET would clarify the relationships between neuroinflammation and depression.

     

Compared to <Superscript>123</Superscript>I-MIBG SPECT/CT, <Superscript>18</Superscript>F-DOPA PET/CT provides accurate tumor extent in patients with extra-adrenal paraganglioma

Aim

The aim of this study was to compare the accuracy of ¹²³I-MIBG SPECT/CT with that of ¹⁸F-DOPA PET/CT for staging extra-adrenal paragangliomas (PGLs) using both functional and anatomical images (i.e., combined cross-sectional imaging) as the reference standards.

Methods

Three men and seven women (age range 26–73 years) with anatomical and/or histologically proven disease were included in this study. Three patients had either metastatic head-and-neck paragangliomas (HNPGLs) or multifocal PGL, and seven patients had nonmetastatic disease. Comparative evaluation included morphological imaging with CT, functional imaging with ¹⁸F-DOPA PET, and ¹²³I-MIBG imaging including SPECT/CT. Imaging results were analyzed on a per-patient and per-lesion basis.

Results

On a per-patient basis, ¹⁸F-DOPA PET’s detection rate for both nonmetastatic and metastatic/multifocal disease was 100%, whereas that of planar ¹²³I-MIBG imaging alone was 10.0% and that of ¹²³I-MIBG SPECT/CT was 20.0%. Overall, on a per-lesion basis, ¹⁸F-DOPA PET showed a sensitivity of 69.2% (McNemar p?<?0.001) compared with anatomical imaging. Sensitivity of planar ¹²³I-MIBG scintigraphy was 5.6%, and that of SPECT/CT was 11.1% (McNemar p?<?0.0001). Overall, ¹⁸F-DOPA PET identified 18 lesions, and anatomical imaging identified 26 lesions; planar ¹²³IMIBG imaging identified only 1 lesion, and SPECT/CT, 2 lesions.

Conclusion

¹⁸F-DOPA PET is more sensitive than is ¹²³I-MIBG imaging, including SPECT/CT, for staging HNPGL. Combined functional and anatomical imaging (PET/CT) is indicated to exclude metastatic disease in extra-adrenal PGL.

     

Three-dimensional visualization of internal vertebral venous plexuses relative to dural sac and spinal nerve root of spinal canal stenosis using MRI

Purpose

The aim of this study was to introduce a new method of producing three-dimensional (3D) images of vertebral venous plexuses (VVPs) by 3D-MRI with and without contrast media, to identify pathoanatomical features that might accelerate or modify spinal canal stenosis.

Methods

We used a 1.5-T MRI unit with two different 3D sequences with and without contrast media. Multi planar reconstruction (MPR) images of VVPs could be obtained by volume image subtraction methods with a workstation for dural sac from whole 3D volume MPR without contrast media, using images before and after gadoteridol injection. Three patients with degenerative lumbar spine disease and one with cervical ossification of the posterior longitudinal ligament (OPLL) were studied with and without contrast media. As three patients underwent operations, we investigated intraoperative microscopic findings, and compared VVP images.

Results

Abundant components of internal VVPs were identified on MRI in correlation with neural tissues such as dura and nerve roots.

Conclusions

Using 3D MRI without and with gadoteridol, we can evaluate morphological changes in VVP under degenerative spinal conditions. The MR anatomy of VVPs of the spine is important, as it has been implicated in many pathophysiological mechanisms and may also cause pitfalls in MRI.

     

Predictive factors for the outcomes of initial I-131 low-dose ablation therapy to Japanese patients with differentiated thyroid cancer

Objective

To identify prognostic factors associated with a low-iodine diet (LID) and the amount of remnant thyroid tissue in Japanese patients with differentiated thyroid cancer (DTC) who received initial I-131 remnant ablation (RAI) using a fixed low dose of I-131 (1110 MBq).

Patients and methods

In this prospective study, we enrolled 45 patients. Patients were classified into a self-managed LID group and a strict LID group. We measured the urinary iodine concentration on the day of RAI after patients consumed LID for 2 weeks. Thyroid-stimulating hormone-induced thyroglobulin (Tg) levels and I-131 uptake by the remnant thyroid tissue were also evaluated. A response-evaluation whole-body scan (WBS) was performed 6–8 months after RAI to determine the outcome of the therapy.

Results

Post-LID urinary iodine levels of the strict LID group tended to be lower than those of the self-managed LID group. Twenty-five cases (56%) showed absence of uptake, whereas 20 cases (44%) showed residual uptake on the response-evaluation WBS. There were no significant differences between “absence” and “residual” groups in urinary iodine concentrations and Tg levels (p?=?0.253 and p?=?0.234, respectively). However, significant differences were observed in I-131 uptake by the thyroid bed (p?=?0.035).

Conclusions

For patients following the current Japanese method of a 2-week LID, the urinary iodine concentration was not a predictive factor for the successful outcome of RAI. In contrast, low I-131 uptake by the thyroid bed, revealed by the scintigram after RAI, may serve as a favorable predictive factor.

     

Implication of different clinical and pathological variables in patients with differentiated thyroid cancer on successful ablation for 3700 MBq <Superscript>131</Superscript>I: a single Egyptian institutional experience over 14 years

Objective

Is to investigate possible factors predicting success of ablation for 3700 MBq radioactive iodine 131 in patients with differentiated thyroid cancer (DTC) following near total thyroidectomy.

Methods

This retrospective study enrolled 272 patients between 2000 and 2014. The success or failure of ablation was assessed 6 months after given the dose and our criteria for complete successful remnant ablation defined as: Negative ¹³¹I whole body scan with no residual functioning thyroid tissue or distant functioning metastases and stimulated thyroglobulin (Tg) level less than 2 ng/ml. Different clinical and pathological factors, such as age, gender, tumor histology, grade and variants, size of primary malignant lesion, stage, and risk assessment according to the American (ATA) and European Thyroid Association (ETA) guidelines, associated pathology, tumor mutifocality, lymph node (LN) metastases and their number, invasiveness of the tumor (capsular invasion of the nodule, extra-thyroidal extension, and vascular invasion), baseline stimulated Tg level, and pre-ablative diagnostic scan were assessed.

Results

There were 185 successful ablations (68 %). The baseline-stimulated Tg measured before the ablation was the only independent predictor of ablation success in multivariate analysis (P < 0.0001) with odds ratio (OR) of 2.64 (95 % CI: 1.54–4.54) and the optimal cutoff for this was 3.8 ng/mL. On the univariate analysis, LN metastases was predictor of ablation failure (P value = 0.03).

Conclusion

Baseline-stimulated Tg level is clinically important and had a significant predictive value for successful ablation; therefore, higher pre-ablation Tg should potentially be incorporated in the decision making for ¹³¹I dosage or other treatment. In accordance with other studies, this is also applicable to cervical lymph nodal involvement and thyroid capsule invasion.

     

MRI-based high-precision irradiation in an orthotopic pancreatic tumor mouse model

Background and purpose

Recently, imaging and high-precision irradiation devices for preclinical tumor models have been developed. Image-guided radiation therapy (IGRT) including innovative treatment planning techniques comparable to patient treatment can be achieved in a translational context. The study aims to evaluate magnetic resonance imaging/computed tomography (MRI/CT)-based treatment planning with different treatment techniques for high-precision radiation therapy (RT).

Materials and methods

In an orthotopic pancreatic cancer model, MRI/CT-based radiation treatment planning was established. Three irradiation techniques (rotational, 3D multifield, stereotactic) were performed with the SARRP system (Small Animal Radiation Research Platform, Xstrahl Ltd., Camberley, UK). Dose distributions in gross tumor volume (GTV) and organs at risk (OAR) were analyzed for each treatment setting.

Results

MRI with high soft tissue contrast improved imaging of GTV and OARs. Therefore MRI-based treatment planning enables precise contouring of GTV and OARs, thus, providing a perfect basis for an improved dose distribution and coverage of the GTV for all advanced radiation techniques.

Conclusion

An MRI/CT-based treatment planning for high-precision IGRT using different techniques was established in an orthotopic pancreatic tumor model. Advanced radiation techniques allow considering perfect coverage of GTV and sparing of OARs in the preclinical setting and reflect clinical treatment plans of pancreatic cancer patients.

     

Lymphocyte function following radium-223 therapy in patients with metastasized,castration-resistant prostate cancer

Purpose

Therapy with the alpha-emitter radium-223 chloride (²²³Ra) is an innovative therapeutic option in patients with metastasized, castration-resistant prostate cancer. However, radiotherapy can lead to hematopoietic toxicity. The aim of this study was to determine if ²²³Ra therapy induces an impairment of cellular antimicrobial immune responses.

Methods

In 11 patients receiving ²²³Ra treatment, lymphocyte proliferation and the production of pro- and anti-inflammatory cytokines (interferon-γ and interleukin-10) were determined, using lymphocyte transformation testing and ELISpot, respectively. Lymphocyte function after stimulation with mitogens and microbial antigens was assessed prior to therapy and at day 1, 7 and 28 after therapy.

Results

Lymphocyte proliferation and the production of interferon-γ and interleukin-10 towards mitogens and antigens remained unchanged after therapy. Consistent with these in vitro data, we did not observe infectious complications after treatment.

Conclusions

The results argue against an impairment of lymphocyte function after ²²³Ra therapy. Thus, immune responses against pathogens should remain unaffected.

     

Sensitivity to change and association of three-dimensional meniscal measures with radiographic joint space width loss in rapid clinical progression of knee osteoarthritis

Objective

To determine whether 3D meniscal measures had similar sensitivity to longitudinal change as cartilage thickness; to what extent these measures are associated with longitudinal joint space width (JSW) change; and whether the latter associations differ between minimum (mJSW) and fixed-location JSW.

Methods

Two-year changes in medial meniscal position and morphology, cartilage thickness (MRI) and minimum and fixed-location JSW (radiography) were determined in 35 Osteoarthritis Initiative knees [12 men, age: 67 (51-77) years; 23 women, age: 65 (54-78) years], progressing from baseline Kellgren-Lawrence grade ≤2 to knee replacement within 3-5 years. Multiple linear regression assessed the features contributing to JSW change.

Results

Meniscal measures, cartilage thickness and JSW displayed similar sensitivity to change (standardised response mean≤|0.76|). Meniscal changes were strongly associated with JSW change (r≤|0.66|), adding ≤20% to its variance in addition to cartilage thickness change. Fixed-location JSW change (multiple r²=72%) was more strongly related to cartilage and meniscal change than mJSW (61%). Meniscal morphology explained more of fixed-location JSW and meniscal position more of mJSW.

Conclusion

Meniscal measures provide independent information in explaining the variance of radiographic JSW change. Fixed-location JSW appears to be more reflective of structural change than mJSW and, hence, a potentially superior measure of structural progression.

Key Points

? 3D positional/morphological meniscal measures change in rapidly progressing knees. ? Similar sensitivity to 2-year change of quantitative meniscal/cartilage measures in rapid progression. ? Changes in meniscal measures are strongly associated with radiographic JSW change. ? Meniscal change provides information to explain JSW variance independent of cartilage. ? Fixed-location JSW reflects structural disease stage more closely than minimum JSW.

     

Predictive value of primary tumor parameters using <Superscript>18</Superscript>F-FDG PET/CT for occult lymph node metastasis in breast cancer with clinically negative axillary lymph node

Objective

This study aimed to demonstrate the clinical significance of total lesion glycolysis (TLG) of primary breast cancer using ¹⁸F-FDG PET/CT to predict axillary lymph node (ALN) metastasis in invasive ductal breast cancer (IDC) with a clinically negative axillary lymph node (cN-ALN).

Methods

135 patients, newly diagnosed with IDC with _CN-ALN between July 2016 and October 2017, were retrospectively enrolled. We estimated primary tumor PET/CT parameters including the maximum standard uptake value (SUV_max), metabolic tumor volume (MTV), and TLG, as well as clinicopathologic findings. All patients received breast surgery followed by pathologic axillary lymph node examination.

Results

Of the 135 patients, 31 (23.0%) were diagnosed with pathologically proven metastatic ALN. In univariate analysis, SUV_max, MTV, and TLG of the primary breast tumor were correlated with metastatic ALN along with tumor size, lymphovascular invasion, CD34, and D2-40. On multivariate analysis, TLG (>?5.74, p?=?0.009) had independent significance for predicting ALN metastasis in IDC with cN-ALN.

Conclusion

We demonstrated that TLG of primary tumors can be useful in predicting pathologic ALN metastasis in IDC patients with cN-ALN.

     

Investigating predictors of ball-throwing velocity in team handball: the role of sex,anthropometry, and body composition

Purpose

In this work we investigated the role of sex, anthropometry and body composition in predicting ball-throwing velocity in skilled team handball players of different competitive level.

Methods

Forty-six handball players (22 males, 24 females) underwent standard anthropometry and body composition analysis using dual-energy X-ray absorptiometry. Ball-throwing velocity in standing throw from 7 m and three-step running throw from 9 m to a left and right goal was evaluated on court using a radar gun.

Results

Results showed that males throw faster than females in all types of throw, independently of several confounding variables. In both sexes, after correction for several confounding variables, bone mineral content and/or density positively correlated with ball-throwing velocity in all types of throw, but lean and fat mass did not. To minimize collinearity problems, we used the sophisticated Random Forests approach to select variables for regression analysis. In the resulting models, bone mineral content and/or density emerged as sole predictors of ball-throwing velocity to a limited (adjusted R ² = 0.10–0.36) albeit significant extent.

Conclusions

It is concluded that, besides sex, the athlete’s bone quality may affect handball-throwing performance, suggesting that specific training aimed at improving bone quality would be of use to players.

     

Antitumor effects of radionuclide treatment using α-emitting <Emphasis Type="Italic">meta</Emphasis>-<Superscript>211</Superscript>At-astato-benzylguanidine in a PC12 pheochromocytoma model

Purpose

Therapeutic options for patients with malignant pheochromocytoma are currently limited, and therefore new treatment approaches are being sought. Targeted radionuclide therapy provides tumor-specific systemic treatments. The β-emitting radiopharmaceutical meta-¹³¹I-iodo-benzylguanidine (¹³¹I-MIBG) provides limited survival benefits and has adverse effects. A new generation of radionuclides for therapy using α-particles including meta-²¹¹At-astato-benzylguanidine (²¹¹At-MABG) are expected to have strong therapeutic effects with minimal side effects. However, this possibility has not been evaluated in an animal model of pheochromocytoma. We aimed to evaluate the therapeutic effects of the α-emitter ²¹¹At-MABG in a pheochromocytoma model.

Methods

We evaluated tumor volume-reducing effects of ²¹¹At-MABG using rat pheochromocytoma cell line PC12 tumor-bearing mice. PC12 tumor-bearing mice received intravenous injections of ²¹¹At-MABG (0.28, 0.56, 1.11, 1.85, 3.70 and 5.55 MBq; five mice per group). Tumor volumes were evaluated for 8 weeks after ²¹¹At-MABG administration. The control group of ten mice received phosphate-buffered saline.

Results

The ²¹¹At-MABG-treated mice showed significantly lower relative tumor growth during the first 38 days than the control mice. The relative tumor volumes on day 21 were 509.2%?±?169.1% in the control mice and 9.6%?±?5.5% in the mice receiving 0.56 MBq (p?<?0.01). In addition, the mice treated with 0.28, 0.56 and 1.11 MBq of ²¹¹At-MABG showed only a temporary weight reduction, with recovery in weight by day 10.

Conclusion

²¹¹At-MABG exhibited a strong tumor volume-reducing effect in a mouse model of pheochromocytoma without weight reduction. Therefore, ²¹¹At-MABG might be an effective therapeutic agent for the treatment of malignant pheochromocytoma.

     

Influence of hilar deposition in the evaluation of the alveolar epithelial permeability on <Superscript>99m</Superscript>Tc-DTPA aerosol inhaled scintigraphy

Purpose

We investigated whether hilar radioaerosol deposition affects the clearance rate of technetium-99m-labeled diethylenetriaminepentaacetic acid (^99mTc-DTPA) from peripheral alveolar regions.

Materials and methods

A total of 38 patients underwent ^99mTc-DTPA inhalation lung scintigraphy. Six region of interest (ROI) patterns were adopted: ROI 1 was outlined around the entire hemithorax, and ROIs 2–6 were outlined around the hemithorax but excluded square ROIs of different size in the hilar region. Half-times (T_½) were calculated with time-activity curves using onecompartment and two-compartment analyses. The T_½ of ROIs 1–5 were plotted against the T_½ of ROI 6, and regression lines were obtained with the least-squares method. The absolute values of the differences between surveyed values and regression line were calculated. The Wilcoxon test for trend and a single linear regression model were used to determine statistical significance.

Results

There were significant reductions in the absolute values of the differences between surveyed values and regression line from ROIs 1–5 by one-component analysis and the fast component of two-compartment analysis (P < 0.001).

Conclusion

Our results suggest that the deposition of radioaerosol in the hilar region affects the clearance rate of ^99mTc-DTPA from the alveoli in damaged lungs. The hilar region should be excluded from ROIs when alveolar epithelial permeability is evaluated.

     

Coronal 2D MR cholangiography overestimates the length of the right hepatic duct in liver transplantation donors

Purpose

To compare the length of the right hepatic duct (RHD) measured on rotatory coronal 2D MR cholangiography (MRC), rotatory axial 2D MRC, and reconstructed 3D MRC.

Materials and methods

Sixty-seven donors underwent coronal and axial 2D projection MRC and 3D MRC. RHD length was measured and categorized as ultrashort (≤1 mm), short (>1-14 mm), and long (>14 mm). The measured length, frequency of overestimation, and the degree of underestimation between two 2D MRC sets were compared to 3D MRC.

Results

The length of the RHD from 3D MRC, coronal 2D MRC, and axial 2D MRC showed significant difference (p?<?0.05). RHD was frequently overestimated on the coronal than on axial 2D MRC (61.2 % vs. 9 %; p?<?.0001). On coronal 2D MRC, four (6 %) with short RHD and one (1.5 %) with ultrashort RHD were over-categorized as long RHD. On axial 2D MRC, overestimation was mostly <1 mm (83.3 %), none exceeding 3 mm or over-categorized. The degree of underestimation between the two projection planes was comparable.

Conclusion

Coronal 2D MRC overestimates the RHD in liver donors. We suggest adding axial 2D MRC to conventional coronal 2D MRC in the preoperative workup protocol for living liver donors to avoid unexpected confrontation with multiple ductal openings when harvesting the graft.

Key Points

? In living liver donors, RHD length influences the number of ductal openings. ? Coronal 2D MRC overestimates the RHD length than does axial 2D MRC. ? Adding axial 2D MRC to coronal 2D MRC may prevent overestimating RHD length.