AIM:To elucidate correlation between signal intensity on diffusion-weighted images (SI-DWI) and clinical backgrounds for uterine adenomyosis and to compare SI-DWI of adenomyosis and malignant uterine tumors.METHODS:This study examined 46 adenomyosis patients diagnosed using magnetic resonance imaging and 25 patients with surgically confirmed malignant uterine myometrial tumor. First, adenomyosis cases were classified visually into high-intensity and low-intensity groups based on the SI-DWI compared with that of normal uterine myometrium. Secondly, correlation was assessed between SI-DWI of adenomyosis and patient clinical background information such as age, menopausal status, menstrual cycle and dysmenorrhea severity. Third, quantitative comparison was made of low-intensity adenomyosis (LIA), high-intensity adenomyosis (HIA) and malignant tumor groups for the signal intensity ratio (SIR) on DWI and the apparent diffusion coefficient (ADC). Their diagnostic performance was evaluated using logistic regression analysis and receiver operating characteristic (ROC) analysis.RESULTS:The 46 adenomyosis cases were classified as 26 low-intensity and 20 high-intensity cases. Significant correlation was found only for menstrual cycle phases. HIA had significantly lower SIR and higher ADC than malignant tumor. The ADC of HIA was significantly higher than that of LIA. The combination of SIR and ADC showed excellent diagnostic performance (area under ROC curve, 0.99).CONCLUSION:There is a variation in signal intensity on DWI of uterine adenomyosis and it is associated with menstrual cycle phase. Adenomyosis with high signal intensity on DWI can be differentiated from malignant lesions by its lower signal intensity on DWI and higher ADC than that found for malignant uterine tumors, however overlaps exist.

Purpose: To investigate the influence of microcystic, elongated and fragmented (MELF) pattern invasion on preoperative evaluation of lymph node (LN) metastasis and myometrial invasion in patients with low-grade endometrial carcinoma. Methods: The study included 192 consecutive patients with low-grade endometrial carcinoma who underwent preoperative computed tomography (CT) and magnetic resonance imaging (MRI), followed by surgery. One hundred sixty one of 192 patients underwent LN dissection and were analyzed for LN metastasis. All patients were analyzed for myometrial invasion. Presence of enlarged LN was evaluated by using size criteria on CT. Depth of myometrial invasion was evaluated on MRI using T-2-weighted imaging, diffusion-weighted imaging and contrast-enhanced T-1-weighted imaging comprehensively. Sensitivity and specificity for LN metastasis and deep myometrial invasion were evaluated for MELF group and non-MELF group. The difference of sensitivity between two groups was compared using Chi-square and Fisher's exact test. Results: MELF pattern invasion was identified in 43/192 patients (22%). LN metastases were observed in 18/39 patients in MELF group and 6/122 patients in non-MELF group for pelvic LN and 11/29 patients in MELF group and 4/57 patients in non-MELF group for para-aortic LN. Sensitivity for the detection of pelvic LN metastasis in MELF group was significantly lower than in non-MELF group (16.7% vs 66.7%). As for the assessment of the deep myometiral invasion, pathological deep myometrial invasion were found in 31/43 patients in MELF group and 32/149 patients in non-MELF group. Sensitivity in MELF group showed lower values than in non-MELF group (54.8% vs 78.1% for reader 1, 54.8% vs 62.5% for reader 2), although there was no statistically significant difference (P = 0.09 for reader 1 and P = 0.72 for reader 2). Conclusion: In case of low-grade endometrial carcinoma with MELF pattern invasion, preoperative staging by CT and MRI have a risk for underestimation.

To determine whether temporal subtraction (TS) CT obtained with non-rigid image registration improves detection of various bone metastases during serial clinical follow-up examinations by numerous radiologists. Six board-certified radiologists retrospectively scrutinized CT images for patients with history of malignancy sequentially. These radiologists selected 50 positive and 50 negative subjects with and without bone metastases, respectively. Furthermore, for each subject, they selected a pair of previous and current CT images satisfying predefined criteria by consensus. Previous images were non-rigidly transformed to match current images and subtracted from current images to automatically generate TS images. Subsequently, 18 radiologists independently interpreted the 100 CT image pairs to identify bone metastases, both without and with TS images, with each interpretation separated from the other by an interval of at least 30 days. Jackknife free-response receiver operating characteristics (JAFROC) analysis was conducted to assess observer performance. Compared with interpretation without TS images, interpretation with TS images was associated with a significantly higher mean figure of merit (0.710 vs. 0.658; JAFROC analysis, P = 0.0027). Mean sensitivity at lesion-based was significantly higher for interpretation with TS compared with that without TS (46.1% vs. 33.9%; P = 0.003). Mean false positive count per subject was also significantly higher for interpretation with TS than for that without TS (0.28 vs. 0.15; P < 0.001). At the subject-based, mean sensitivity was significantly higher for interpretation with TS images than that without TS images (73.2% vs. 65.4%; P = 0.003). There was no significant difference in mean specificity (0.93 vs. 0.95; P = 0.083). TS significantly improved overall performance in the detection of various bone metastases.

To evaluate the clinical feasibility of a newly developed mobile PET system with MR-compatibility (flexible PET; fxPET), compared with conventional PET (cPET)/CT for brain imaging. Twenty-one patients underwent cPET/CT with subsequent fxPET/MRI using 18F-FDG. As qualitative evaluation, we visually rated image quality of MR and PET images using a four-point scoring system. We evaluated overall image quality for MR, while we evaluated overall image quality, sharpness and lesion contrast. As quantitative evaluation, we compared registration accuracy between two modalities [(fxPET and MRI) and (cPET and CT)] measuring spatial coordinates. We also examined the accuracy of regional 18F-FDG uptake. All acquired images were of diagnostic quality and the number of detected lesions did not differ significantly between fxPET/MR and cPET/CT. Mean misregistration was significantly larger with fxPET/MRI than with cPET/CT. SUVmax and SUVmean for fxPET and cPET showed high correlations in the lesions (R = 0.84, 0.79; P < 0.001, P = 0.002, respectively). In normal structures, we also showed high correlations of SUVmax (R = 0.85, 0.87; P < 0.001, P < 0.001, respectively) and SUVmean (R = 0.83, 0.87; P < 0.001, P < 0.001, respectively) in bilateral caudate nuclei and a moderate correlation of SUVmax (R = 0.65) and SUVmean (R = 0.63) in vermis. The fxPET/MRI system showed image quality within the diagnostic range, registration accuracy below 3 mm and regional 18F-FDG uptake highly correlated with that of cPET/CT.

Granulocyte colony-stimulating factor (G-CSF)-producing tumors have an aggressive clinical course. Here, we report five cases of G-CSF-producing tumors and review the literature, focusing on imaging findings related to tumor-produced G-CSF. In addition to our cases, we identified 30 previous reports of G-CSF-producing tumors on which 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET)/CT, bone scintigraphy, or evaluation of bone marrow MR findings was performed. White blood cell count, serum C-reactive protein, and serum interleukin-6 were elevated in all cases for which these parameters were measured. G-CSF-producing tumors presented large necrotic masses (mean diameter 83.2 mm, range 17–195 mm) with marked FDG uptake (mean maximum standardized uptake value: 20.09). Diffuse FDG uptake into the bone marrow was shown in 28 of the 31 cases in which FDG-PET/CT was performed. The signal intensity of bone marrow suggested marrow reconversion in all seven MRI-assessable cases. Bone scintigraphy demonstrated no significant uptake, except in two cases with bone metastases. Splenic FDG uptake was increased in 8 of 10 cases in which it was evaluated. These imaging findings may reflect the effects of tumor-produced G-CSF. The presence of G-CSF-producing tumors should be considered in patients with cancer who show these imaging findings and marked inflammatory features of unknown origin.

PURPOSE:We aimed to evaluate mid- to long-term results of endovascular treatment for portal vein thrombosis (PVT) after living-donor liver transplantation (LDLT).METHODS:Thirty cases (14 males, 16 females; age range, 0.67-65 years) who underwent endovascular treatment including thrombolysis, angioplasty, stent placement, and/or collateral embolization for PVT after LDLT from 2001 to 2017 were retrospectively reviewed. Clinical and procedural data were collected and analyzed regarding the patency of the PVT site at the last follow-up date (PVT-free persistency) using Log-rank test. Results were considered statistically significant at P < 0.05.RESULTS:Median follow-up was 120 months. The technical success rate was 80% (n=24). Patency rates at 1 week and 1, 3, 6, 12, 36, and 60 months were 73%, 59%, 55%, 51%, 51%, 51%, and 51% for primary patency and 80%, 70%, 66%, 66%, 66%, 61%, and 61% for assisted patency after secondary endovascular treatment. PVT-free persistency rates regarding the subgroups were as follows: children under 12 years vs. adults, 50% vs. 68% (P = 0.42); acute vs. nonacute, 76% vs. 46% (P = 0.10); localized vs. extensive, 90% vs. 50% (P = 0.035); transileocolic approach vs. percutaneous-transhepatic approach, 71% vs. 54% (P = 0.39); and thrombolysis-based treatment vs. non-thrombolysis-based treatment, 71% vs. 44% (P = 0.12), respectively. Among technically successful cases, PVT-free persistency rate was 94% for those with hepatopetal flow in the peripheral portal vein vs. 17% for those without hepatopetal flow (P < 0.001). The only major complication occurring was pleural hemorrhage (n=1). Minor complications (i.e., fever) occurred in 18 patients (60%).CONCLUSION:In conclusion, mid- to long-term portal patency following endovascular treatment was approximately 50%-60% in PVT patients after LDLT. PVT site patency over three months after the first endovascular treatment, localized PVT, and hepatopetal flow in the peripheral portal vein were identified as key prognostic factors for mid- to long-term portal patency.

BackgroundHypothalamic–pituitary–thyroid (HPT) maturation has not been extensively evaluated using neonatal MRI, even though both structures are visualized on MRI.HypothesisThat signal intensity and volume of pituitary and thyroid (T) glands on MRI in neonates may be interrelated.Study TypeRetrospective.SubjectsIn all, 102 participants.Field Strength/Sequence3.0T, T1‐weighted pointwise encoding time reduction with radial acquisition (PETRA).AssessmentThe volume of interest of the anterior pituitary (AP), posterior pituitary (PP), and T on MRI were defined on T1‐PETRA by two radiologists, and volumes of AP (AP_vol) and thyroid (T_vol) were calculated. Gestational age (GA), chronological age (CA), GA+CA, birth weight (BW), and thyroid function were recorded. Mean and maximum signal intensities of AP, PP, and T were normalized using signals from the pons and spinal cord as follows: signal ratio of anterior pituitary/pons (AP/pons), signal ratio of posterior pituitary/pons (PP/pons), and signal ratio of thyroid/cord (T/cord) T/cord, respectively.Statistical TestsCorrelations between signal intensity and volume measures and GA, CA, GA+CA, and BW were assessed using Pearson's correlation coefficient or Spearman's rank correlation coefficient. Thyroid function analysis and Tmean/cord, Tmax/cord, and T_vol were evaluated using the Steel–Dwass test.ResultsAPmean/pons correlated positively with GA (ρ = 0.62, P < 0.001) and BW (ρ = 0.74, P < 0.001), and negatively with CA (ρ = −0.86, P < 0.001) and GA+CA (ρ = −0.46, P < 0.001). PPmean/pons correlated positively with GA (ρ = 0.49, P < 0.001) and BW (ρ = 0.63, P < 0.001), and negatively with CA (ρ = −0.70, P < 0.001) and GA+CA (r = −0.38, P < 0.001). Tmean/cord correlated positively with GA (ρ = 0.48, P < 0.001) and BW (ρ = 0.55, P < 0.001), and negatively with CA (ρ = −0.59, P < 0.001) and GA+CA (ρ = −0.22, P = 0.03). AP_vol correlated positively with GA (ρ = 0.68, P < 0.001) and BW (ρ = 0.73, P < 0.001), and negatively with CA (ρ = −0.72, P < 0.001). T_vol correlated positively with GA (ρ = 0.50, P < 0.001) and BW (ρ = 0.61, P < 0.001), and negatively with CA (ρ = −0.54, P < 0.001). APmean/pons correlated positively with Tmean/cord (ρ = 0.61, P < 0.001).Data ConclusionSignal and volume of pituitary and thyroid glands correlated positively with GA and BW, and negatively with CA in neonates.Level of Evidence4Technical Efficacy Stage5

Several studies have evaluated the usefulness of deep learning for lung segmentation using chest X‐ray (CXR) images with small‐ or medium‐sized abnormal findings. Here, we built a database including both CXR images with severe abnormalities and experts' lung segmentation results, and aimed to evaluate our network's efficacy in lung segmentation from these images. For lung segmentation, CXR images from the Japanese Society of Radiological Technology (JSRT, N = 247) and Montgomery databases (N = 138) were included, and 65 additional images depicting severe abnormalities from a public database were evaluated and annotated by a radiologist, thereby adding lung segmentation results to these images. U‐net was used to segment the lungs in images from the three databases. Subsequently, the U‐net network architecture was automatically optimized for lung segmentation from CXR images using Bayesian optimization. Dice similarity coefficient (DSC) was calculated to confirm segmentation. Our results demonstrated that using baseline U‐net yielded poorer lung segmentation results in our database than those in the JSRT and Montgomery databases, implying that robust segmentation of lungs may be difficult because of severe abnormalities. The DSC values with baseline U‐net for the JSRT, Montgomery and our databases were 0.979, 0.941, and 0.889, respectively, and with optimized U‐net, 0.976, 0.973, and 0.932, respectively. For robust lung segmentation, the U‐net architecture was optimized via Bayesian optimization, and our results demonstrate that the optimized U‐net was more robust than baseline U‐net in lung segmentation from CXR images with large‐sized abnormalities.

Pancreatic β-cell mass (BCM) has a central importance in the pathophysiology of diabetes mellitus. Recently, pancreatic β-cell-specific imaging, especially positron emission tomography (PET) with exendin-based probes, has emerged for non-invasive evaluation of BCM. We developed a novel exendin-based probe labeled with fluorine-18, [18F]FB(ePEG12)12-exendin-4 (18F-Ex4) for PET imaging. We subsequently conducted a first-in-human phase 1 study of 18F-Ex4 PET/computed tomography (CT) and investigated the safety and utility for visualizing the pancreas. Six healthy male subjects were enrolled in this study. A low dose (37.0 MBq) of 18F-Ex4 PET/CT was administered (first cohort: n = 2), and subsequently a higher dose (74.0 MBq) was administered (second cohort: n = 4). In the first and second cohorts, 38.6 ± 4.8 and 71.1 ± 4.8 MBq of 18F-Ex4 were administered, respectively. No serious adverse events were observed in both groups. Only one participant in the first cohort showed transient hypoglycemia during the PET scans. 18F-Ex4 PET/CT successfully visualized the pancreas in all participants. The mean standardized uptake value of the pancreas was found to be higher than that in the surrounding organs, except for the bladder and kidney, during the observation. Dosimetry analyses revealed the effective systemic doses of 18F-Ex4 as 0.0164 ± 0.0019 mSv/MBq (first cohort) and 0.0173 ± 0.0020 mSv/MBq (second cohort). 18F-Ex4 PET/CT demonstrated the safety and utility for non-invasive visualization of the pancreas in healthy male subjects. 18F-Ex4 is promising for clinical PET imaging targeting pancreatic β cells.

Purpose: We aimed to investigate the performance of high resolution-diffusion-weighted imaging (HR-DWI) using readout-segmented echo-planar imaging in visualizing malignant breast lesions and evaluating their extent, using pathology as a reference. Methods: This retrospective study included patients who underwent HR-DWI with surgically confirmed malignant breast lesions. Two radiologists blinded to the final diagnosis evaluated HR-DWI independently and identified the lesions, measuring their maximum diameters. Another radiologist confirmed if those lesions were identical to the pathology. The maximum diameters of the lesions between HR-DWI and pathology were compared, and their correlations were calculated using Spearman's correlation coefficient. Apparent diffusion coefficient (ADC) values of the lesions were measured. Results: Ninety-five mass/64 non-mass lesions were pathologically confirmed in 104 females. Both radiologists detected the same 93 mass lesions (97.9%). Spearman's correlation coefficient for mass lesions were 0.89 and 0.90 (P < 0.0001 and 0001) for the two radiologists, respectively. The size differences within 10 mm were 90.3% (84/93) and 94.6% (88/93) respectively. One radiologist detected 35 non-mass lesions (54.7%) and another radiologist detected 32 non-mass lesions (50.0%), of which 28 lesions were confirmed as identical. Spearman's correlation coefficient for non-mass lesions were 0.59 and 0.22 (P = 0.0002 and 0.22), respectively. The mean ADC value of mass lesions and non-mass lesions were 0.80 and 0.89 x 10(-3) mm(2)/s, respectively. Conclusion: Using HR-DWI, malignant mass lesions were depicted with excellent agreement with the pathological evaluation. Approximately half of the non-mass lesions could not be identified, suggesting a current limitation of HR-DWI.

Tumor-induced osteomalacia (TIO) is caused by typically small tumors that secrete fibroblast growth factor 23 (FGF23). As tumor resection is the only effective treatment for TIO, it is important to detect the culprit tumor. We aimed to assess the utility of 68Gallium-DOTA-D-Phe(1)-Tyr(3)-octreotide (68Ga-DOTATOC) PET/CT in TIO and the correlation between biochemical parameters and the PET/CT results. Thirty-five patients with clinically suspected TIO who had undergone 68Ga-DOTATOC PET/CT were retrospectively analyzed. 68Ga-DOTATOC PET/CT results were compared with biochemical parameters and the final diagnosis, including histopathology. 68Ga-DOTATOC PET/CT detected focal uptake consistent with TIO in 21/35 patients, one of which was considered false positive. In 16 patients, the cause of osteomalacia was confirmed histologically as phosphaturic mesenchymal tumor (n = 15) or fibrous dysplasia (n = 1). The other four patients were judged clinically as true positive by subsequent MRI and the clinical course. Overall, the detection rate of 68Ga-DOTATOC PET/CT was 57% (20/35). Median tumor maximum standardized uptake value (SUVmax) was 6.9 (range 1.5–37.7). There was no significant difference in serum intact FGF23 level between DOTATOC-positive and DOTATOC-negative cases, and no significant correlation was observed between intact FGF23 level and tumor SUVmax. 68Ga-DOTATOC PET/CT was clinically useful in detecting culprit tumors and subsequent patient management in TIO.

Predicting pathogenic germline variants (PGVs) in breast cancer patients is important for selecting optimal therapeutics and implementing risk reduction strategies. However, PGV risk factors and the performance of prediction methods in the Japanese population remain unclear. We investigated clinicopathological risk factors using the Tyrer‐Cuzick (TC) breast cancer risk evaluation tool to predict BRCA PGVs in unselected Japanese breast cancer patients (n = 1,995). Eleven breast cancer susceptibility genes were analyzed using target‐capture sequencing in a previous study; the PGV prevalence in BRCA1 , BRCA2 , and PALB2 was 0.75%, 3.1%, and 0.45%, respectively. Significant associations were found between the presence of BRCA PGVs and early disease onset, number of familial cancer cases (up to third‐degree relatives), triple‐negative breast cancer patients under the age of 60, and ovarian cancer history (all P < .0001). In total, 816 patients (40.9%) satisfied the National Comprehensive Cancer Network (NCCN) guidelines for recommending multigene testing. The sensitivity and specificity of the NCCN criteria for discriminating PGV carriers from noncarriers were 71.3% and 60.7%, respectively. The TC model showed good discrimination for predicting BRCA PGVs (area under the curve, 0.75; 95% confidence interval, 0.69‐0.81). Furthermore, use of the TC model with an optimized cutoff of TC score ≥0.16% in addition to the NCCN guidelines improved the predictive efficiency for high‐risk groups (sensitivity, 77.2%; specificity, 54.8%; about 11 genes). Given the influence of ethnic differences on prediction, we consider that further studies are warranted to elucidate the role of environmental and genetic factors for realizing precise prediction.

OBJECTIVE:To develop and evaluate a radiomics approach for classifying histological subtypes and epidermal growth factor receptor (EGFR) mutation status in lung cancer on PET/CT images.METHODS:PET/CT images of lung cancer patients were obtained from public databases and used to establish two datasets, respectively to classify histological subtypes (156 adenocarcinomas and 32 squamous cell carcinomas) and EGFR mutation status (38 mutant and 100 wild-type samples). Seven types of imaging features were obtained from PET/CT images of lung cancer. Two types of machine learning algorithms were used to predict histological subtypes and EGFR mutation status: random forest (RF) and gradient tree boosting (XGB). The classifiers used either a single type or multiple types of imaging features. In the latter case, the optimal combination of the seven types of imaging features was selected by Bayesian optimization. Receiver operating characteristic analysis, area under the curve (AUC), and tenfold cross validation were used to assess the performance of the approach.RESULTS:In the classification of histological subtypes, the AUC values of the various classifiers were as follows: RF, single type: 0.759; XGB, single type: 0.760; RF, multiple types: 0.720; XGB, multiple types: 0.843. In the classification of EGFR mutation status, the AUC values were: RF, single type: 0.625; XGB, single type: 0.617; RF, multiple types: 0.577; XGB, multiple types: 0.659.CONCLUSIONS:The radiomics approach to PET/CT images, together with XGB and Bayesian optimization, is useful for classifying histological subtypes and EGFR mutation status in lung cancer.

A 78-year-old woman was referred to the gynecologic outpatient department because she was suspected of having ovarian cancer based on an imaging study performed during a general medical examination. Further examination using(18)F-FDG PET/CT revealed a bulky mass lesion with low FDG avidity, as well as surprisingly strong bilateral breast radiotracer uptake despite the patient's age. Thus, an estrogen-producing tumor was suspected. Bilateral salpingo-oophorectomy was performed, and surgical pathology diagnosed the tumor as clear cell carcinoma of the ovary.

BackgroundUltrafast dynamic contrast‐enhanced (UF‐DCE) breast MRI is considered a promising method of accelerated breast MRI. However, the value of new kinetic parameters derived from UF‐DCE need clinical evaluation.PurposeTo evaluate the diagnostic performance of the maximum slope (MS), time to enhancement (TTE), and time interval between arterial and venous visualization (AVI) derived from UF‐DCE MRI using compressed sensing (CS).Study TypeRetrospective.PopulationSeventy‐five patients with histologically proven breast lesions. The total number of analyzed lesions was 90 (61 malignant and 29 benign).Field Strength/Sequence3T MRI with UF‐DCE MRI based on the 3D gradient‐echo volumetric interpolated breath‐hold examination (VIBE) sequence using incoherent k‐space sampling combined with a CS reconstruction followed by conventional DCE MRI.AssessmentThe diagnostic performance of the MS, TTE, AVI, and conventional kinetic analysis was analyzed and compared with histology.Statistical TestsWilcoxon rank sum test, receiver operating characteristic analysis.ResultsThe MS was larger and the TTE and AVI were smaller for malignant lesions compared with benign lesions: MS: 29.3%/s and 18.4%/s (P < 0.001), TTE: 7.0 and 12.0 seconds (P < 0.001), AVI: 2.7 and 4.4 frames (P = 0.006) for malignant and benign lesions. The discriminating power of the MS (area under the curve [AUC], 0.76) was slightly better than that of conventional kinetic analysis (AUC, 0.69) and comparable to that of the TTE and AVI (AUC, 0.78 and 0.76 for TTE and AVI, respectively). Invasive lobular carcinoma had smaller MS (21.8%/s) among malignant lesions (29.3%/s).Data ConclusionThe MS, TTE, and AVI can be used to evaluate breast lesions with clinical performance equivalent to that of conventional kinetic analysis. These parameters vary among histologies.Level of Evidence: 3Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;51:164–174.

Background Ultrasonography (US) is useful when implanting fiducial markers in the liver. However, the implant position is sometimes lost. Recently, real-time image fusion technology (Volume Navigation [V-navi]; GE Healthcare, Milwaukee, WI, USA) has been introduced as a technique for using images from different modalities, and its utility for fiducial marker implantation has been hypothesized. Purpose To evaluate the utility of US-guided fiducial marker implantation in the liver using V-navi compared to conventional US. Material and Methods We retrospectively reviewed 35 patients who underwent fiducial marker implantation for stereotactic body radiation therapy of liver tumors in 2013–2018. To avoid artifacts obscuring the tumor, the target point of implantation was set 10 mm cranial or caudal to the tumor. Marker implantation was then performed using US alone (US group, n = 24) or V-navi with computed tomography (CT) or magnetic resonance imaging (V-navi group, n = 11). Postprocedural CT was evaluated to determine technical success, distances between marker and either tumor surface or target point, and whether marker-induced artifacts obscured the tumor. Complications were also evaluated. Results were compared between groups. Results Technical success was obtained in 33 patients. Distance between the tumor and marker showed no significant difference between groups. Distance between target point and marker was shorter in the V-navi group ( P = 0.0093). Tumor-obscuring artifacts were seen in 12 patients (V-navi group, n = 1; US group, n = 11; P = 0.055). The only complication was minor bleeding in the US group (n = 1). Conclusion V-navi appears useful for US-guided fiducial marker implantation in the liver compared with conventional US.

In patients with advanced ovarian, fallopian and primary peritoneal carcinoma, complete interval debulking surgery (IDS) is often performed after neoadjuvant chemotherapy (NAC) to achieve long progression-free survival (PFS) and overall survival (OS). We aimed to investigate the utility of 2-deoxy-2-[F-18]fluoro-d-glucose (FDG) PET/CT in patients with these malignancies who underwent complete IDS. Between 2009 and 2017, twenty-two patients underwent FDG PET/CT scans before and after NAC. The highest SUVmax/peak (standardized uptake value), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) for whole lesions were defined as target SUVmax/peak, tMTV and tTLG, respectively. We also calculated these reduction rates during NAC. These parameters were compared between the groups with platinum-free interval (PFI) > 12 months (n = 10) and those with PFI ≤ 12 months (n = 12). The PFS and OS were evaluated using these quantitative parameters, and in terms of the presence of visually detectable residual lesions after NAC. The target SUVmax/peak before NAC, the reduction rates in the target SUVmax, tMTV and tTLG were significantly higher in the group with PFI > 12 months than the shorter PFI group (p < 0.05). Especially in PFS, the higher reduction rates in the target SUVmax/peak, tMTV, and tTLG had an excellent prognostic stratification (p < 0.05) and the FDG visually negative group after NAC had a significantly better prognosis than the other group (p < 0.01). The reduction rate of FDG PET-based quantitative values and visual analysis after NAC demonstrated prognostic potential, especially in PFS.