Difference in arterial FDG accumulation in healthy study participants between digital PET/CT and standard PET/CT.

OBJECTIVE: To evaluate the differences in FDG accumulation in arteries throughout the body between digital and standard PET/CT. METHODS: Forty-six people who had FDG-PET examinations with a digital PET/CT scanner for health screening between April 2020 and March 2021 and had previous examinations with a standard PET/CT scanner were the study participants. FDG accumulation in arteries throughout the body was visually assessed in each segment. Scan was considered positive when arterial FDG accumulation was equal to or greater than that of the liver. The positivity rates for general arteries and each arterial segment were compared between the two kinds of scanners. If any one of the arterial segments was considered positive, the general arteries were classified as positive. Moreover, the rate of change in results from the standard PET/CT to the digital scanner in the same individual (negative to positive, positive to negative) was examined. RESULTS: In the evaluation of general arteries, the positivity rates were 21.7% (10 cases) for the standard PET/CT, whereas positive rates were 97.8% (45 cases) for the digital PET/CT (p < 0.001). In all arterial segments, the positivity rate was significantly higher with the digital PET/CT compared to the standard PET/CT; those with the digital PET/CT were, respectively, 95.7%, 87.0%, 73.9%, 37.0%, 34.8%, and 21.7% in the femoral, brachial, aortic, subclavian, iliac, and carotid arteries. On the other hand, those with the standard PET/CT were 13.0%, 13.0%, 19.6%, 2.2%, 0%, and 4.4% in segments in the above order. Changes from negative to positive were shown in many cases; 35 cases (76.0%) of general arteries, 38 cases (82.6%) for the femoral artery, and 34 cases (73.9%) for the brachial artery. The exception was one case in which a change from positive to negative was confirmed in the carotid artery. In all arteries considered to be positive, FDG accumulation was not greater than but was equal to that in the liver with both scanners. CONCLUSIONS: Arterial FDG accumulation was significantly higher with digital PET/CT compared to conventional PET/CT. With digital PET/CT, an arterial FDG accumulation equal to the liver may not to be considered as abnormal accumulation.

Spontaneous regression of small cell lung cancer associated with Lambert-Eaton Myasthenic Syndrome: Case report.

Spontaneous regression (SR) of cancer is very rare, especially of small cell lung cancer (SCLC). Recently, an association of paraneoplastic neurological syndrome (PNS) has been reported as a cause of SR of cancer, and onconeural antibodies are a possible factor in the SR of cancer associated with PNS. We herein report the first case of SR of SCLC combined with anti-P/Q-type of voltage-gated calcium channel (VGCC) antibody-positive Lambert-Eaton myasthenic syndrome (LEMS), a subtype of PNS. This case report suggests that SCLC may be spontaneously reduced by an autoimmune response induced by VGCC antibodies associated with LEMS. Our finding may help elucidate the mechanisms that inhibit tumor growth and cause the regression of tumors.

A case of pulmonary pleomorphic carcinoma associated with cystic airspace.

Lung cancer associated with a cystic airspace is frequently misdiagnosed or overlooked. Adenocarcinoma, followed by squamous cell carcinoma, is the most typical histologic type of lung cancer connected to a cystic airspace. Here we present the rare case of lung pleomorphic carcinoma associated with a cystic airspace. We encountered a 74-year-old Japanese man diagnosed by computed tomography (CT) as having a nodule outside a cystic airspace in the lung. Several previous CT images showed that the cystic airspace preceded the nodule. Postsurgery, pathology indicated a diagnosis of pleomorphic carcinoma. Since pulmonary pleomorphic carcinomas pursue an aggressive clinical course, their early detection may contribute to an improved prognosis. Our case demonstrated that pleomorphic carcinoma can arise with cystic airspaces. For early diagnosis of those aggressive lung cancers, chest physicians should carefully examine the walls of cystic airspaces on CT.

Predicting the pathological invasiveness of early lung adenocarcinoma prior to surgery using Deauville criteria: reliability and validity.

PURPOSE: This retrospective study aimed to investigate the validity and reliability of FDG-PET/CT visual assessment using Deauville criteria to predict pathological invasiveness of early lung adenocarcinoma prior to surgery. MATERIALS AND METHODS: Between April 2020 and January 2022, 51 patients who underwent surgery for pathological stage 0/I lung adenocarcinoma were enrolled. The pulmonary lesions were divided into two groups according to pathological invasiveness: less invasive (including adenocarcinoma in situ and minimally invasive adenocarcinoma and invasive adenocarcinoma. We compared CT size (total and solid size), SUVmax, and Deauville score between the two groups. Furthermore, we investigated inter-rater and intra-rater agreements regarding the Deauville score. Receiver operating characteristic (ROC) curve analysis was performed to identify the diagnostic performance of each method. RESULTS: Based on pathologic diagnoses, 51 lesions in the 51 patients were divided into 6 less invasive and 45 invasive adenocarcinoma lesions. According to quadratic-weighted Kappa statistics, inter-rater (k = 0.93) and intra-rater (k = 0.97) agreements among all five components of the Deauville score indicated high agreement. There was a statistically significant difference in CT solid size, SUVmax, and Deauville score between the two groups. There were no significant differences between CT solid size and FDG-PET/CT assessments (AUC = 0.93 for Deauville score and SUVmax, AUC = 0.84 for CT solid size). CONCLUSION: FDG-PET/CT visual assessment using the Deauville score could assist in deciding upon minimally invasive surgery for early lung adenocarcinoma.

Perceptual and objective physical quality of chest images: a comparison between digital radiographic chest images processed for cancer screening and pneumoconiosis screening in Japan.

This study (1) evaluated the perceptual and objective physical quality of digital radiographic chest images processed for different purposes (routine hospital use, lung cancer screening, and pneumoconiosis screening), and (2) quantified objectively the quality of chest images visually graded by the Japan National Federation of Industrial Health Organization (ZENEIREN). Four observers rated the images using a visual grading score (VGS) according to ZENEIREN's quality criteria. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured. Between groups, differences were assessed using ANOVA (followed by Bonferroni multiple comparisons) or unpaired t-test. The Pearson's correlation coefficients were calculated for the correlation between perceptual quality and objective physical image quality. The image quality perceived by the observers and the SNR measurements were highest for the images generated using parameters recommended for lung cancer screening. The images processed for pneumoconiosis screening were rated poorest by the observers and showed the lowest objective physical quality measurements. The chest images rated high quality by ZENEIREN generally showed a higher objective physical image quality. The SNR correlated well with VGS, but CNR did not. Highly significant differences between the processing parameters indicate that image processing strongly influences the perceptual quality of digital radiographic chest images.

18F FDG-PET/CT analysis of spread through air spaces (STAS) in clinical stage I lung adenocarcinoma.

OBJECTIVE: The purpose of this retrospective study was to investigate the utility of F-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F FDG-PET/CT) to predict spread through air spaces (STAS) in clinical stage I lung adenocarcinoma. METHODS: Between April 2020 and January 2022, 52 patients (55 lesions) who underwent surgery for clinical stage I lung adenocarcinoma were enrolled. The lesions were divided into two groups according to the presence of STAS. 18F FDG-PET/CT parameters, specifically the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), were calculated. The SUVmax, MTV, and TLG were compared between the two groups upon surgical pathological examination. Receiver operating characteristic (ROC) curve analysis was performed to identify a cut-off value. RESULTS: Nineteen lesions (35%) were positive for STAS and 36 lesions were negative for STAS. According to the presence of STAS, significant differences were detected in the SUVmax (5.21 [range 1.52-16.50] vs. 2.42 [range 0.74-11.80], p = 0.0040) but not MTV (3.44 [range 0.65-24.36] vs. 2.95 [0.00-20.07], p = 0.20) and TLG (7.92 [range 0.93-47.82] vs. 5.63 [0.00-58.66], p = 0.14). SUVmax had an AUC value of 0.74 (95% CI 0.61-0.87) with a sensitivity of 89.5% and specificity of 52.8% at a cut-off of 2.48. CONCLUSIONS: SUVmax rather than MTV and TLG were shown to be valuable indices for the prediction of STAS in clinical stage I lung adenocarcinoma.

A case of maxillary cancer treated by intra-arterial therapy using a steerable microcatheter.

We report on a 69-year-old man with locally-advanced left maxillary sinus cancer who underwent treatment with intra-arterial chemoradiotherapy. Angiography showed that the main feeding arteries were the left maxillary artery and the ophthalmic artery, arising from the internal carotid artery. Due to acute branching of the ophthalmic artery, conventional microcatheters could not be inserted. Using a steerable microcatheter, we were able to repeatedly administer chemoradiotherapy via the ophthalmic artery. The tumor has mostly disappeared after intra-arterial chemoradiotherapy, and the patient is still alive two years after treatment. A steerable microcatheter is very useful for acute-angled vascular branches.

Pancreatic FDG uptake on follow-up PET/CT in patients with cancer.

To evaluate the breakdown of unexpected pancreatic 18F-fluorodeoxyglucose (FDG) uptake and the proportion of secondary primary pancreatic cancer on follow-up, patients with cancer underwent positron emission tomography/computed tomography (PET/CT). The participants consisted of 4,473 consecutive patients with cancer who underwent follow-up PET/CT between January 2015 and March 2019 at Kochi Medical School. Among the participants, 225 with a history of pancreatic cancer were excluded from the present study. Retrospective and blinded PET/CT evaluations of 4,248 patients were performed. In patients with pancreatic FDG uptake, the distribution of FDG uptake in the pancreas was evaluated. The final diagnosis was determined pathologically. A total of 14 (0.3%) of the 4,248 patients exhibited FDG uptake in the pancreatic area. Pancreatic abnormalities were detected in 14 patients, and included five cases of pancreatic metastases (36%), four cases of secondary primary pancreatic cancer (29%), two cases of lymph node metastases (14%), one case of malignant lymphoma (7%), one case of autoimmune pancreatitis (7%) and one case of pseudolesion (7%). One patient with early-stage secondary primary pancreatic cancer had a maximum standardized uptake value (SUVmax) <3.0. The remaining 13 patients had a SUVmax >3.0 in the pancreas. Of the 14 patients, two had multiple foci of FDG uptake in the pancreas. Patients with multiple foci of FDG uptake exhibited pancreatic metastasis from renal cell carcinoma and malignant lymphoma. In conclusion, the majority of patients with unexpected pancreatic FDG uptake on follow-up PET/CT exhibited malignancies; furthermore, ~30% of the malignancies detected in patients with pancreatic FDG uptake were secondary primary pancreatic cancers. In patients with unexpected pancreatic FDG uptake on follow-up PET/CT, primary cancer should be considered as well as metastatic tumors.

Efficacy of arterial infusion of iodized oil on CT-guided cryoablation for renal cell carcinoma.

PURPOSE: To evaluate the effectiveness of the transarterial infusion of iodized oil and gelatin particles for marking before CT-guided percutaneous cryoablation (PCA) in patients with renal cell carcinoma (RCC). MATERIAL AND METHODS: This study included ten patients (seven men, three women; mean age 53 years) with 13 RCCs between July 2016 and September 2017. The transarterial infusion of iodized oil and gelatin particles was considered successful when iodized oil accumulated in the target area on CT. CT value of the tumor before and after marking was measured and two diagnostic radiologists evaluated the visualization scores by using a five-point scale (5 = excellent to 1 = invisible). RESULTS: Preoperative marking was successful in all 13 tumors; the median visualization score was 5 post-lipiodol marking and 4 at the time of PCA. The mean CT density was 597 ± 371 Hounsfield units (HU) just after marking and 437 ± 234 HU at the time of PCA. All 13 CT-guided PCA procedures were successful. There were no significant complications. During follow-up (median 11.5 ± 7.0 months) there were no local recurrences. CONCLUSION: As the transarterial infusion of iodized oil and gelatin particles improved RCC visualization on CT, its delivery before CT-guided PCA may improve its safety and success rate in patients with RCC.

Evaluation of pleural lesions after pleurodesis with OK-432 by fluorodeoxyglucose-positron emission tomography/CT.

OBJECTIVE: This study aimed to determine changes in FDG-PET/CT after pleurodesis with OK-432 and to investigate differences in the changes between non-malignant and malignant lesions. METHODS: Study participants were 17 patients with a history of malignant chest disease who underwent FDG-PET/CT after pleurodesis using OK-432 and in whom pleural lesions were determined to be non-malignant (n = 8) or malignant (n = 9). FDG uptake (SUVmax) was counted on all pleural lesions. CT findings (CT attenuation, shape) of pleural lesions with increased FDG uptake were evaluated. RESULTS: The number of patients with increased FDG uptake in the pleura differed significantly between the non-malignant group (3/8) and malignant group (9/9) (p < 0.01) The mean SUVmax of non-malignant lesions with increased FDG uptake was 2.3 ± 0.7 vs. 6.2 ± 2.2 in malignant lesions, for a significant difference (p < 0.01). The mean CT attenuation of lesions was 36 ± 11 HU in the non-malignant group and 34 ± 14 HU in the malignant group, a difference that was not significant (p = 0.91). There was a significant difference in nodular and linear shapes between non-malignant and malignant lesions (p < 0.01). All non-malignant lesions were linear. CONCLUSIONS: Positive FDG uptake was shown in non-malignant pleural lesions as well as in malignant pleural lesions after pleurodesis using OK-432. Combined analysis of FDG accumulation and CT morphology is helpful to distinguish between benign and malignant lesions.

Time-Dependent Effects of Cryoablation for Renal Tumor on Overall and Split Renal Function.

PURPOSE: To evaluate the influence of percutaneous cryoablation for renal cell carcinoma on function of the affected kidney. MATERIALS AND METHODS: Between June 2016 and September 2017 at our institution, 12 inoperable patients underwent 15 cryoablation sessions for 17 small renal tumors. Of these, 9 patients who underwent 11 sessions of cryoablation were the focus of this study. For those patients, time-dependent changes in postoperative renal function were investigated by a retrospective review of clinical records. Evaluated were the estimated glomerular filtration rate (eGFR) and scintigraphy using 99m technetium-mercaptoacetyltriglycine (99mTc-MAG3) before and 1 week, 1-2 months, and more than 6 months after cryoablation. RESULTS: Mean baseline eGFR was 76.88 ± 29.82 mL/min/1.73 m2 (mean ± standard deviation; range, 23.4-112.5). Mean eGFR 1 week, 1-2 months, and more than 6 months after cryoablation were 74.56 ± 26.68 mL/min/1.73 m2 (21.0-101.1), 69.5 ± 25.28 mL/min/1.73 m2 (24.1-105.6), and 75.08 ± 26.25 mL/min/1.73 m2 (29.0-107.3), respectively. Changes were statistically insignificant (P = .6044, P = .6699, and P = .9038, respectively). Regarding split renal function, the mean baseline contribution of the affected kidney determined by 99mTc-MAG3 was 47.27% ± 6.14 (38.8%-57.0%). Mean contributions of the affected kidney 1 week after, 1-2 months after, and more than 6 months after cryoablation were 44.40% ± 5.37 (38.3%-53.6%), 44.57% ± 6.52 (34.35%-55.0%), and 45.41% ± 7.77 (34.4%-56.5%), respectively. Differences from baseline were significant for the earliest 2 periods (P = .0473 and P = .0334, respectively) but not the later period (P = .2532). CONCLUSIONS: Results suggested that total renal function does not worsen after cryoablation; however, function of the affected kidney worsened after cryoablation but later partially recovered.

Comparison of MRI and 123I-FP-CIT SPECT for the evaluation of MSA-P clinical severity.

The aim of the present study was to compare the efficacy of magnetic resonance imaging (MRI) and 123I-labeled 2ß-carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl)nortropane single photon emission computed tomography (123I-FP-CIT SPECT) for determining the clinical severity of patients with multiple system atrophy with Parkinsonism (MSA-P). MRI and 123I-FP-CIT SPECT images from 17 patients with MSA-P as diagnosed using the Unified MSA Rating Scale part IV (UMSARS IV) score were compared. Brain MRI scans were available for all 17 patients and 123I-FP-CIT SPECT images were available for 12 patients. Putaminal atrophy (PA), hyperintense putaminal rim (HPR), hyperintense pons (hot cross bun sign, HCB), atrophy of the cerebellar vermis and hemisphere (cerebellar atrophy, CA) and other abnormalities were evaluated in the MRI scans. Distribution of striatal uptake (SU) and the specific binding ratio (SBR) on each side of the bilateral striatum were evaluated using 123I-FP-CIT SPECT images. No significant associations were observed between HPR, HCB, CA and UMSARS IV score. However, the frequency of PA increased significantly with higher UMSARS IV score (P<0.05). No significant association was observed between UMSARS IV score and SBR. The results of the present study suggest that PA, which is known to be a diagnostic indicator for MSA-P, may be used to determine the clinical severity of MSA-P with greater efficacy than other MRI findings, including HPR, HCB and CA and 123I-FP-CIT SPECT results.

Remote effects in the ipsilateral thalamus and/or contralateral cerebellar hemisphere using FDG PET in patients with brain tumors.

PURPOSE: To evaluate reduced metabolism in the ipsilateral thalamus (TH) and/or contralateral cerebellum (CE) according to tumor localization and cortical metabolism around the tumor in patients with brain tumors based on FDG uptake. METHODS: This study investigated 48 consecutive patients with solitary cerebral hemisphere parenchymal brain tumors who underwent PET/CT and MRI. Patients were divided into 4 groups (A: reduced uptake in ipsilateral TH and contralateral CE, B: reduced uptake in ipsilateral TH only, C: reduced uptake in contralateral CE only, and D: no reduced uptake in ipsilateral TH or contralateral CE). FDG uptake and MRI findings were compared among these groups. RESULTS: Of 48 patients, group A included 24 (50%), group B included 10 (21%), group C included 0, and group D included 14 (29%). No significant tendencies were observed between the groups regarding tumor localization. However, reduced cortical metabolism around the tumor was observed in 22 patients in group A, 7 patients in group B, and 1 patient in group D. All patients in group B showed reduced metabolism from around the tumor up to the ipsilateral TH. CONCLUSION: Reduced FDG uptake in ipsilateral TH and contralateral CE usually occur simultaneously in patients with solitary brain tumors.

Prediction of the ablated area prior to radiofrequency ablation for liver tumor under CT guidance.

PURPOSE: To evaluate the usefulness of a method we developed to predict the ablation area at the time of CT guided radiofrequency (RF) ablation for liver tumors on a CT workstation. MATERIAL AND METHODS: Ten tumors (mean diameter 15.5 mm, range, 9.0-21.5 mm) in seven patients with hepatocellular carcinoma for which CT guided RF ablation was performed were subjects of this study. After advancing the electrode, plain CT was obtained. Then a simulated ball to predict the ablated area was created on the workstation. After confirming that the tumor was sufficiently within the ball, ablation was performed. The distance of the edge of the actual ablated area from that of the predicted ablated area was measured at six points in three cross-sectional directions on CT images after ablation. RESULTS: The procedures were successfully performed without complications. No local recurrence occurred. Mean absolute value of the distance of the gap between the actual and predicted ablated areas was 3.06 ± 2.18 mm (range: 0 to 9 mm). At 29 (55.8%) points, the actual ablated area was smaller than the predicted ablated area; it was larger in 17 (32.7%), and was the same in 6 (11.5%) points. CONCLUSION: Our method produces an acceptable simulation during RF ablation under CT guidance.

Use of proximal side-hole micro-balloon catheter in transcatheter hepatic arterial chemoembolization.

We report on a 70-year-old man with unresectable multiple hepatocellular carcinomas who underwent treatment with transcatheter hepatic arterial chemoembolization. In treating a tumor in segment 1 of the liver, the proximal side-hole micro-balloon catheter, which has been newly developed, was useful.