Short-term hepatocyte function and portal hypertension outcomes of sofosbuvir/velpatasvir for decompensated hepatitis C-related cirrhosis.

BACKGROUND: It is unclear whether hepatocyte function and/or portal hypertension improves if a sustained virologic response (SVR) is achieved with direct-acting antivirals in patients with decompensated hepatitis C-related cirrhosis. METHODS: We examined the safety and efficacy of a 12-week course of sofosbuvir/velpatasvir (SOF/VEL) in 20 patients with decompensated hepatitis C-related cirrhosis. We also investigated changes in the hepatocyte receptor index (LHL15) and blood clearance index (HH15) by Tc-99 m-galactosyl human serum albumin scintigraphy, liver stiffness measurement (LSM) by transient elastography, and hepatic venous pressure gradient (HVPG) in patients who achieved an SVR at 24 weeks after treatment (SVR24). RESULTS: One patient discontinued treatment because of rectal variceal hemorrhage, and 19 patients completed treatment. SVR24 was achieved in 17 patients (89%). Median LHL15 increased from 0.72 pre-treatment to 0.82 after SVR24 (p = 0.012), and median HH15 decreased from 0.82 pre-treatment to 0.76 after SVR24 (p = 0.010). The percentage of patients with LSM ≥ 20 kPa was 90% before treatment and remained at 90% after SVR24. However, the percentage with severe portal hypertension (defined as HVPG ≥ 12 mmHg) decreased from 92% pre-treatment to 58% after SVR24 (p = 0.046). Patients with a decreased HVPG from pre-treatment to after SVR24 had a smaller pre-treatment spleen volume than those with an increased HVPG (median, 252 vs. 537 mL, p = 0.028). CONCLUSION: Achieving SVR24 with SOF/VEL treatment in patients with decompensated hepatitis C-related cirrhosis can be expected to improve hepatocyte function and portal hypertension on short-term follow-up.

[Development of Dose Management Software Using Visual Basic for Applications and Dose Evaluation in the Field of Nuclear Medicine].

PURPOSE: The purpose of this study was to develop software for smooth dose management based on the Japan diagnostic reference levels (DRLs 2020) in the field of nuclear medicine. METHOD: Using the programming language Visual Basic for Applications (VBA), we implemented a function for calculating actual doses, a function for comparing doses at one's own facility with those of DRLs 2020, a function for calculating appropriate doses for pediatric nuclear medicine examinations, and so on. In addition, we evaluated actual doses before and after the software implementation. RESULT: The software enabled easy calculation of actual doses and comparison with DRLs 2020 for smooth dose management. Furthermore, we were able to use the results of dose evaluation to determine the dosage at our facility and to use them as a reference for optimization. CONCLUSION: In the field of nuclear medicine, it is possible to manage doses in accordance with DRLs 2020 by introducing own software into our clinical practice.

Predicting the Prognosis of Prostate Cancer Bone Metastasis Using the Bone Scan Index and Hot Spots Calculated Using VSBONEⓇ Bone Scan Index from Tc-99m-Hydroxymethylene Diphosphonate Bone Scintigraphy.

INTRODUCTION: The bone scan index (BSI) is widely used as a quantitative indicator of bone metastasis, therapeutic effect assessment, and prognosis prediction in prostate cancer. However, the BONE NAVI, which calculates BSI, only supports bone scintigraphy using Tc-99m-methylene diphosphonate. We developed the VSBONEⓇ BSI, which calculates BSI from bone scintigraphy using Tc-99m-hydroxymethylene diphosphonate (HMDP). The purpose of this study was to demonstrate that the BSI calculated using VSBONEⓇ BSI and hot spots (HS), which indicates the number of abnormal accumulations, are useful prognostic factors for patients with prostate cancer bone metastasis, similar to BONE NAVI. METHODS: We analyzed 322 patients who underwent bone scintigraphy for prostate cancer bone metastasis at our hospital. Initial bone scintigraphy was performed using Tc-99m-HMDP. All cases were retrospectively examined for their outcome and time to the final outcome. The results obtained were compared with the BSI and HS calculated using VSBONEⓇ BSI. RESULTS: When the patients were divided into two groups, HS >2 and HS ≤2, the HS ≤2 group had a significantly longer survival time (p < 0.001). In addition, when divided into two groups, BSI >0.46 and BSI ≤0.46, the survival time of the BSI ≦0.46 group was significantly longer (p < 0.001). CONCLUSION: BSI and HS obtained using VSBONEⓇ BSI may be useful as prognostic predictors, similar to those obtained using BONE NAVI.

Deep learning-based detection of parathyroid adenoma by 99mTc-MIBI scintigraphy in patients with primary hyperparathyroidism.

OBJECTIVE: It is important to detect parathyroid adenomas by parathyroid scintigraphy with 99m-technetium sestamibi (99mTc-MIBI) before surgery. This study aimed to develop and validate deep learning (DL)-based models to detect parathyroid adenoma in patients with primary hyperparathyroidism, from parathyroid scintigrams with 99mTc-MIBI. METHODS: DL-based models for detecting parathyroid adenoma in early- and late-phase parathyroid scintigrams were, respectively, developed and evaluated. The training dataset used to train the models was collected from 192 patients (165 adenoma cases, mean age: 64 years ± 13, 145 women) and the validation dataset used to tune the models was collected from 45 patients (30 adenoma cases, mean age: 67 years ± 12, 37 women). The images were collected from patients who were pathologically diagnosed with parathyroid adenomas or in whom no lesions could be detected by either parathyroid scintigraphy or ultrasonography at our institution from June 2010 to March 2019. The models were tested on a dataset collected from 44 patients (30 adenoma cases, mean age: 67 years ± 12, 38 women) who took scintigraphy from April 2019 to March 2020. The models' lesion-based sensitivity and mean false positive indications per image (mFPI) were assessed with the test dataset. RESULTS: The sensitivity was 82% [95% confidence interval 72-92%] with mFPI of 0.44 for the scintigrams of the early-phase model and 83% [73-92%] with mFPI of 0.31 for the scintigrams of the delayed-phase model in the test dataset, respectively. CONCLUSIONS: The DL-based models were able to detect parathyroid adenomas with a high sensitivity using parathyroid scintigraphy with 99m-technetium sestamibi.

Extraction of metastasis hotspots in a whole-body bone scintigram based on bilateral asymmetry.

PURPOSE: A hotspot of bone metastatic lesion in a whole-body bone scintigram is often observed as left-right asymmetry. The purpose of this study is to present a network to evaluate bilateral difference of a whole-body bone scintigram, and to subsequently integrate it with our previous network that extracts the hotspot from a pair of anterior and posterior images. METHODS: Input of the proposed network is a pair of scintigrams that are the original one and the flipped version with respect to body axis. The paired scintigrams are processed by a butterfly-type network (BtrflyNet). Subsequently, the output of the network is combined with the output of another BtrflyNet for a pair of anterior and posterior scintigrams by employing a convolutional layer optimized using training images. RESULTS: We evaluated the performance of the combined networks, which comprised two BtrflyNets followed by a convolutional layer for integration, in terms of accuracy of hotspot extraction using 1330 bone scintigrams of 665 patients with prostate cancer. A threefold cross-validation experiment showed that the number of false positive regions was reduced from 4.30 to 2.13 for anterior and 4.71 to 2.62 for posterior scintigrams on average compared with our previous model. CONCLUSIONS: This study presented a network for hotspot extraction of bone metastatic lesion that evaluates bilateral difference of a whole-body bone scintigram. When combining the network with the previous network that extracts the hotspot from a pair of anterior and posterior scintigrams, the false positives were reduced by nearly half compared to our previous model.

Per-rectal portal scintigraphy as an alternative measure of hepatic venous pressure gradient in chronic liver disease: A preliminary report.

AIM: Hepatic venous pressure gradient (HVPG) measurement is a gold standard for the diagnosis of portal hypertension but can be invasive and difficult to conduct. Per-rectal portal scintigraphy (PRPS) can estimate portal haemodynamics noninvasively. However, no report to date has examined the association between HVPG and PRPS in patients with chronic liver disease, including cirrhosis. METHODS: This single-centre study included a total of 21 patients with chronic liver disease who underwent HVPG measurement and PRPS. For PRPS, the transit times from injection of the radiotracer to its inflow into the liver (TTL) and heart (TTH) were set and the time difference between TTL and TTH (TDLH) was calculated, while the shunt index (SI) was measured. RESULTS: Cirrhosis was observed in 18 cases (86%), and the median HVPG was 13 mmHg. HVPG (p = 0.028), TTL (p = 0.018), TDLH (p = 0.003) and SI (p = 0.033) were higher in patients with oesophageal varices (EV). Considering the diagnostic ability for EV, the area under the curve was 0.88 for TDLH and 0.80 for HVPG. TDLH was significantly correlated with the risk of EV rupture (p = 0.004). CONCLUSION: Patients with chronic liver disease should undergo upper gastrointestinal endoscopy when the TDLH is high.

Assessment of a software for semi-automatically calculating the bone scan index on bone scintigraphy scans.

AIMS: The incidence of bone metastases exceeds 85% in patients who die from prostate cancer. Bone scintigraphy is the most widely used method for the early detection of bone metastases in prostate cancer. We developed a software program that semi-automatically calculated the bone scan index (BSI) on technetium-99m hydroxymethylene diphosphonate bone scintigraphy scans with a computer-aided diagnosis system (CAD) and examined whether the BSI calculated using this software could replace the extent of disease (EOD) score. METHODS: The subjects were 175 patients who were diagnosed with prostate cancer at our hospital and underwent bone scintigraphy. We analyzed receiver operating characteristic curves to determine the BSI cutoff value between EOD groups. The cutoff value was determined based on the maximum value of the sum of the sensitivity and specificity. RESULTS: BSI cutoff values of 0.20, 1.56, and 4.56 were used to distinguish between EOD 0 and 1-4 (sensitivity [87.2%] and specificity [100.0%]), between EOD 0- and 2-4 (sensitivity [85.2%] and specificity [92.0%]), and between EOD 0-2 and 3-4 (sensitivity [88.4%] and specificity [99.2%]), respectively. CONCLUSION: Our results suggest that this software can calculate BSI, and the software may play a role in predicting prognosis and selecting an appropriate treatment strategy. If a sufficient number of other nuclear medicine tests are performed, creating a similar CAD system is possible.

Study of the Usefulness of Bone Scan Index Calculated From 99m-Technetium- Hydroxymethylene Diphosphonate (99mTc-HMDP) Bone Scintigraphy for Bone Metastases from Prostate Cancer Using Deep Learning Algorithms.

BACKGROUND: BSI calculated from bone scintigraphy using 99mtechnetium-methylene diphosphonate (99mTc-MDP) is used as a quantitative indicator of metastatic bone involvement in bone metastasis diagnosis, therapeutic effect assessment, and prognosis prediction. However, the BONE NAVI, which calculates BSI, only supports bone scintigraphy using 99mTc-MDP. AIMS: We developed a method in collaboration with the Tokyo University of Agriculture and Technology to calculate bone scan index (BSI) employing deep learning algorithms with bone scintigraphy images using 99mtechnetium-hydroxymethylene diphosphonate (99mTc-HMDP). We used a convolutional neural network (CNN), enabling the simultaneous processing of anterior and posterior bone scintigraphy images named CNNapis. OBJECTIVES: The purpose of this study is to investigate the usefulness of the BSI calculated by CNNapis as bone imaging and bone metabolic biomarkers in patients with bone metastases from prostate cancer. METHODS: At our hospital, 121 bone scintigraphy scans using 99mTc-HMDP were performed and analyzed to examine bone metastases from prostate cancer, revealing the abnormal accumulation of radioisotope (RI) at bone metastasis sites. Blood tests for serum prostate-specific antigen (PSA) and alkaline phosphatase (ALP) were performed concurrently. BSI values calculated by CNNapis were used to quantify the metastatic bone tumor involvement. Correlations between BSI and PSA and between BSI and ALP were calculated. Subjects were divided into four groups by BSI values (Group 1, 0 to <1; Group 2, 1 to <3; Group 3, 3 to <10; Group 4, >10), and the PSA and ALP values in each group were statistically compared. RESULTS: Patients diagnosed with bone metastases after bone scintigraphy were also diagnosed with bone metastases using CNNapis. BSI corresponding to the range of abnormal RI accumulation was calculated. PSA and BSI (r = 0.2791) and ALP and BSI (r = 0.6814) correlated positively. Significant intergroup differences in PSA between Groups 1 and 2, Groups 1 and 4, Groups 2 and 3, and Groups 3 and 4 and in ALP between Groups 1 and 4, Groups 2 and 4, and Groups 3 and 4 were found. CONCLUSION: BSI calculated using CNNapis correlated with ALP and PSA values and is useful as bone imaging and bone metabolic biomarkers, indicative of the activity and spread of bone metastases from prostate cancer.

Correction to: Automated measurement of bone scan index from a whole-body bone scintigram.

The article Automated measurement of bone scan index from a whole-body bone scintigram.

Automated measurement of bone scan index from a whole-body bone scintigram.

PURPOSE: We propose a deep learning-based image interpretation system for skeleton segmentation and extraction of hot spots of bone metastatic lesion from a whole-body bone scintigram followed by automated measurement of a bone scan index (BSI), which will be clinically useful. METHODS: The proposed system employs butterfly-type networks (BtrflyNets) for skeleton segmentation and extraction of hot spots of bone metastatic lesions, in which a pair of anterior and posterior images are processed simultaneously. BSI is then measured using the segmented bones and extracted hot spots. To further improve the networks, deep supervision (DSV) and residual learning technologies were introduced. RESULTS: We evaluated the performance of the proposed system using 246 bone scintigrams of prostate cancer in terms of accuracy of skeleton segmentation, hot spot extraction, and BSI measurement, as well as computational cost. In a threefold cross-validation experiment, the best performance was achieved by BtrflyNet with DSV for skeleton segmentation and BtrflyNet with residual blocks. The cross-correlation between the measured and true BSI was 0.9337, and the computational time for a case was 112.0 s. CONCLUSION: We proposed a deep learning-based BSI measurement system for a whole-body bone scintigram and proved its effectiveness by threefold cross-validation study using 246 whole-body bone scintigrams. The automatically measured BSI and computational time for a case are deemed clinically acceptable and reliable.

Evaluation of ablation of thyroid remnants with 1850 MBq iodine-131 in 67 patients with thyroid cancer.

BACKGROUND: Radioiodine remnant ablation (RRA) is used to destroy residual normal thyroid tissue after total thyroidectomy in differentiated thyroid carcinoma (DTC) patients. As 1850-MBq RRA is routinely performed at our facility, we evaluated the outcomes. METHODS: Sixty-seven DTC patients without macroscopic residual lesions after total thyroidectomy were evaluated. Thyroglobulin (Tg) was measured 2-3 months before RRA with thyroxin administration (pretreatment); just before ablation after a 3-week iodine intake restriction with thyroxin withdrawal (THW) (N.=16) or recombinant human thyroid-stimulating hormone (rhTSH) stimulation (N.=51); and 3 months after RRA, after a 2-week iodine intake restriction and 3-week THW (N.=57) or rhTSH stimulation (N.=10). All patients received 131I (1850 MBq) treatment followed by 131I scintigraphy about 8 days later (8.18±0.91) and 131I scintigraphy (185 MBq) after the dosage 24 hours later 3months after RRA. Initial RRA goal was defined as negatively visible uptake in 131I thyroid bed (VUT) and a Tg level of <2 ng/mL 3 months after RRA. RESULTS: Rest 60 patients whose TSH levels were below 0.5 µIU/mL of all 67 patients were evaluated. Negatively VUT on 3 months after RRA was shown in 56 out of 60 patients (93.3%). Initial RRA goal was achieved in 21 (42.0%) of 50 patients, excluding 3 patients whose Tg levels 3 months after RRA were not measured and 7 patients with anti-Tg antibodies. Pretreatment Tg levels (P=0.0003) was significant predictive factor for Initial RRA goal on multivariate logistic regression analysis. CONCLUSIONS: RRA with 1850 MBq is effective by visual diagnosis, about 40% of all intermediate or high-risk DTC patients achieved initial RRA goals by both visual and Tg levels diagnosis.

Prognostic significance of pretreatment 18F-fluorodeoxyglucose positron emission tomography evaluation using metabolic tumor volume of the primary tumor and lymph nodes in advanced hypopharyngeal cancer.

BACKGROUND: The purpose of this study was to retrospectively evaluate the usefulness of pretreatment positron emission tomography (PET) using metabolic tumor volume (MTV) of the primary tumor and lymph nodes in advanced hypopharyngeal cancer. METHODS: From June 2007 to December 2015, consecutive patients with advanced hypopharyngeal cancer who underwent PET and were treated with definitive radiation therapy were retrospectively reviewed. RESULTS: A total of 61 patients were eligible for this study. On multivariate analysis, MTV of the primary tumor (MTV-T) was significantly related to the local control rate and overall survival (OS) (P = .036 and .012, respectively). In patients with lower MTV-T, MTV of metastatic lymph nodes (MTV-N) was significantly related to disease-specific survival and OS (P = .012 and .017, respectively). CONCLUSION: MTV-T is a significant predictor in patients with advanced hypopharyngeal cancer, and MTV-N is also significant in patients with lower MTV-T.

Heterogeneous liver uptake of Tc-99m-GSA as quantified through SPECT/CT helps to evaluate the degree of liver fibrosis: A retrospective observational study.

Tc-99m-galactosyl human serum albumin (GSA) scintigraphy is used to assess the hepatic functional reserve, and allows for visual assessment of the residual hepatocyte distribution on single-photon emission computed tomography/computed tomography (SPECT/CT) images. The association between heterogeneous liver uptake of Tc-99m-GSA and liver fibrosis remains to be studied in detail. We analyzed this association.Fifty-one patients with chronic hepatobiliary disease undergoing a Tc-99m-GSA scintigraphy were included in this study. The receptor (LHL15) and blood clearance (HH15) indexes (the uptake ratios of the liver and heart) were obtained from dynamic planar images. The liver uptake count maximum-to-mean ratio (LUC Max/Mean) was calculated from single-photon emission computed tomography/computed tomography (SPECT/CT) images as an indicator of the Tc-99m-GSA liver uptake heterogeneity. We assessed the relationship between these quantified values and liver fibrosis.There were 30 Child-Pugh classification grade A patients, 16 grade B patients, and 5 grade C patients. Among the 30 patients whose liver histopathology was evaluable, those with advanced liver fibrosis (F2-4) had a lower LHL15 than those with mild liver fibrosis (F0-1) (median, 0.90 vs. 0.92, P = .04), and a higher LUC Max/Mean (median, 1.80 vs. 1.70, P = .02). The multivariate analysis identified platelets (P = .04) and the LUC Max/Mean (P = .04) as contributing factors of advanced liver fibrosis.These findings suggest that Tc-99m-GSA SPECT/CT can be used not only to assess the hepatic functional reserve, but also to evaluate a degree of liver fibrosis.

[Using Super Resolution to Denoise on PET Images].

A high-resolution display panel comes to practical use, but the resolution of the indicated contents does not change. The up-sampling processing is applied to indication of the low-resolution contents. In the up-sampling process, the super resolution enables an up-sampling process which estimates information of high frequency components lost by sampling while analyzing input images is noticed. In this paper, we aimed at reconstructing an image of normal resolution in which the influence of statistical noise is reduced by applying super resolution after down-sampling processing is applied to positron emission tomography (PET) image with many statistical noises. To evaluate the noise reduction effect, we compared it with the Gaussian filter which is frequently used to reduce the influence of the statistical noise of the PET image. A 3D Hoffman brain phantom was used to evaluate objectively by peak signal-to-noise ratio and power spectral density. The objective index of the PET image applying super resolution is positive results, suggesting the possibility of being useful as compared with the conventional method.

Scatter Correction of Septal Penetration for 123I-IMP Cerebral Blood Flow SPECT Adding Radioactivity from the Outside of Field of View-Comparison between Simulation-based and Multi-window Scatter Corrections.

PURPOSE: The N-Isopropyl-p-[123I] Iodoamphetamine (123I-IMP) SPECT imaging reduces the image quality and quantitative accuracy due to scatter and septal penetration occurred by radioactive uptake from outside of the field of view such as the lungs. We evaluated the influence of scatter and septal penetration using phantom-simulated radioactivity from outside of the field of view, and subsequently compared the effect of scatter and septal penetration corrections between the simulation-based effective scatter source estimation (ESSE) method and the multi-window method (ellipse approximation method). METHODS: We used the phantom filled with 10 and 25 kBq/mL for the brain and lung parts corresponding to radioactive concentration in the clinical study. The SPECT images were acquired with and without lung phantom using low-energy high-resolution (LEHR) and cardiac high-resolution (CHR) collimators. We quantitatively evaluated a brain phantom by count analysis and coefficient of variation as reference data without lung phantom simulated the radioactivity from outside of the field of view, and compared between two scatter corrections by each collimator. RESULTS: The brain count in cerebral base with the ESSE method using LEHR collimator was higher than that of the ellipse approximation method. The whole brain count with the ellipse approximation method using CHR collimator shows 28.8% lower than the ESSE method, so that it suggests that the ellipse approximation method for LEHR collimator and the ESSE method for CHR collimator was close to reference counts. The coefficient of variation of the ESSE method was lower than that of the ellipse approximation method for both two collimators. CONCLUSIONS: It was possible to correct the scatter and penetration from outside the field of view with high accuracy, by using the ellipse approximation method with LEHR collimator and the ESSE method with CHR collimator.

Regional Liver Disorder with Differences in the Accumulation of 99mTc-phytate and 99mTc-galactosyl Human Serum Albumin.

We report a 56-year-old woman with regional liver disorder due to acute hepatitis. Computed tomographic images showed low signal density at a plain phase and prolonged contrast effect at a late phase in the left hepatic lobe, in which an accumulation of 99mTc-phytate increased, whereas that of 99mTc-galactosyl human serum albumin (GSA) decreased. Meanwhile, in the right lobe, an accumulation of 99mTc-GSA showed more increased than that of 99mTc-phytate. Liver biopsy showed massive hepatocyte necrosis and interface hepatitis in the left lobe, and moderate hepatitis in the right lobe. Differences in the accumulation between these scintigrams were helpful for understanding rapid necrosis in the left lobe, resulting in a compensatory enlargement of the right lobe. Clinicians should be aware that some cases of acute hepatitis cause regional liver disorder although most cases show homogeneous inflammation.

Usefulness of Stereotactic Radiotherapy Using CyberKnife for Recurrent Lymph Node Metastasis of Differentiated Thyroid Cancer.

A woman in her 60s presented with a recurrent lymph node metastasis from a papillary thyroid carcinoma in the right parapharyngeal space. She had already undergone total thyroidectomy, five resections for cervical lymph node metastases, and right carotid rebuilding. Surgical resection of the current metastasis was impossible. 131I-radioiodine therapy (RIT) with 3.7 GBq 131I was not effective; therefore, stereotactic radiation therapy (SRT) using a CyberKnife radiotherapy system was scheduled. The prescription dose was 21 Gy, and a dose covering 95% of the planning target volume (PTV) in three fractions was administered. The PTV was 4,790 mm3. Follow-up magnetic resonance imaging conducted 3 and 12 months after the SRT demonstrated a remarkable and gradual reduction of the recurrent lymph node metastasis in the right parapharyngeal space and no evidence of recurrence. For multidisciplinary therapy of unresectable and/or RIT unresponsive locoregional lymph node metastases and recurrences of DTC, SRT using the CyberKnife system should be considered.

[Imaging of hyperparathyroidism-Ultrasonography and 99mTc-MIBI scintigraphy-].

Treatments for primary hyperparathyroidism due to adenoma, hyperplasia and carcinoma and secondary hyperparathyroidism are mainly surgical resections of them. Accurate imaging diagnoses of the existences and the regions are very important for reductions of invasiveness. We describe ultrasonography and (99m)Tc-MIBI scintigraphy of hyperparathyroidism. We explain an advantage, a disadvantage and diagnosability of these modalities. We mention utilities of SPECT/CT, too. We show echogram and (99m)Tc-MIBI scintigraphy images about 3 cases of hyperparathyroidism.