Recent progress in the applications of presynaptic dopaminergic positron emission tomography imaging in parkinsonism

Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.This review provides a comprehensive summary of the latest developments in the application of presynaptic dopaminergic positron emission tomography imaging in disorders that manifest parkinsonism.We conducted a thorough literature search using reputable databases such as PubMed and Web of Science.Selection criteria involved identifying peer-reviewed articles published within the last 5 years,with emphasis on their relevance to clinical applications.The findings from these studies highlight that presynaptic dopaminergic positron emission tomography has demonstrated potential not only in diagnosing and differentiating various Parkinsonian conditions but also in assessing disease severity and predicting prognosis.Moreover,when employed in conjunction with other imaging modalities and advanced analytical methods,presynaptic dopaminergic positron emission tomography has been validated as a reliable in vivo biomarker.This validation extends to screening and exploring potential neuropathological mechanisms associated with dopaminergic depletion.In summary,the insights gained from interpreting these studies are crucial for enhancing the effectiveness of preclinical investigations and clinical trials,ultimately advancing toward the goals of neuroregeneration in parkinsonian disorders.

Rim^(18)F-fluorodeoxyglucose uptake of hepatic cavernous hemangioma on positron emission tomography/computed tomography:A case report

BACKGROUND Peripheral FDG accumulation in a hepatic hemangioma presenting in a patient with prolonged fever is rare.Therefore,clinicians should pay close attention to patients with hepatic mass.CASE SUMMARY A 54-year-old woman with a 4-wk history of daily fevers was admitted to our hospital.A whole body^(18)-Fluordesoxyglucose(PET-FDG)positron emission tomography/computed tomography(PET/CT)was performed to elucidate the source of the fever.However,whole body^(18)-FDG PET/CT raised the suspicion of a malignant lesion because of peripheral FDG accumulation(SUVmax 3.5 g/mL)higher than that of the normal liver parenchyma(SUVmax 1.6 g/mL)surrounding a hypoactive area,and no other abnormalities were showed.Subsequently,the patient underwent liver mass resection.Histopathology showed a hepatic cavernous hemangioma with fatty infiltration around the lesion.The fever disappeared four days after surgery and the patient did not present any complications during follow-up.CONCLUSION Fatty infiltration in the peripheral parts of hepatic cavernous hemangioma may lead to subacute inflammation which further activate the Kupffer cells.This may cause prolonged fever and peripheral rim FDG accumulation on PET/CT.

Guiding function of positron emission tomographycomputed tomography examination in the diagnosis and treatment of ocular adnexal mucosa associated lymphoid tissue lymphoma

AIM:To explore the role of positron emission tomographycomputed tomography(PET-CT)examination in the diagnosis and treatment of ocular adnexal mucosa associated lymphoid tissue lymphoma(OAML).METHODS:The general clinical data,postoperative PET-CT results,treatment regimens,and the prognosis of 21 histopathologically confirmed OAML patients between October 2017 and September 2021 were collected.Among the 21 patients,five patients underwent surgical treatment alone,13 patients underwent surgical treatment combined with radiotherapy,and three patients underwent surgical treatment combined with chemotherapy.RESULTS:The follow-up period ranged from 8 to 79mo,with four cases of recurrence and no deaths.Through PETCT examination,two patients exhibited both local ocular metabolic elevation and systemic metastasis,and one of these patients had cervical lymph node metastasis,while the other had submandibular and parotid gland metastasis.Nine patients showed only local ocular metabolic elevation,while 10 patients had no abnormal metabolic activity locally.CONCLUSION:PET-CT examination plays a crucial role in detecting residual lesions and recurrence following tumor resection,aiding in precise disease staging,and facilitating the development of personalized treatment plans,ultimately improving patient prognosis.

Application of ^(18)F-fluorodeoxyglucose positron emission tomography/computed tomography imaging in recurrent anastomotic tumors after surgery in digestive tract tumors

BACKGROUND This study was to investigate the application value of whole-body dynamic ^(18)F-fluorodeoxyglucose(FDG)positron emission tomography/computed tomogra-phy(PET/CT)imaging in recurrent anastomotic tumors of digestive tract after gastric and esophageal cancer surgery.Postoperative patients with gastric and esophageal cancer have a high risk of tumor recurrence,and traditional imaging methods have certain limitations in early detection of recurrent tumors.Whole-body dynamic ^(18)F-FDG PET/CT imaging,due to its high sensitivity and specifi-city,can provide comprehensive information on tumor metabolic activity,which is expected to improve the early diagnosis rate of postoperative recurrent tumors,and provide an important reference for clinical treatment decision-making.METHODS A retrospective analysis was performed on 53 patients with upper digestive tract tumors after operation and systemic dynamic ^(18)F-FDG PET/CT imaging indi-cating abnormal FDG uptake by anastomosis,including 29 cases of gastric cancer and 24 cases of esophageal cancer.According to the follow-up results of gas-troscopy and other imaging examinations before and after PET/CT examination,the patients were divided into an anastomotic recurrence group and anastomotic inflammation group.Patlak multi-parameter analysis software was used to obtain the metabolic rate(MRFDG),volume of distribution maximum(DVmax)of anastomotic lesions,and MRmean and DVmean of normal liver tissue.The lesion/background ratio(LBR)was calculated by dividing the MRFDG and DVmax of the anastomotic lesion by the MRmean and DVmean of the normal liver tissue,respectively,to obtain LBR-MRFDG and LBR-DVmax.An independent sample t test was used for statistical analysis,and a receiver operating characteristic curve was used to analyze the differential diagnostic efficacy of each parameter for anastomotic recurrence and inflammation.RESULTS The dynamic ^(18)F-FDG PET/CT imaging parameters MRFDG,DVmax,LBR-MRFDG,and LBR-DVmax of postoperative anastomotic lesions in gastric cancer and esophageal cancer showed statistically significant differences between the recurrence group and the inflammatory group(P<0.05).The parameter LBR-MRFDG showed good diagnostic efficacy in differentiating anastomotic inflammation from recurrent lesions.In the gastric cancer group,the area under the curve(AUC)value was 0.935(0.778,0.993)when the threshold was 1.83,and in the esophageal cancer group,the AUC value was 1.When 86 is the threshold,the AUC value is 0.927(0.743,0.993).CONCLUSION Whole-body dynamic ^(18)F-FDG PET/CT imaging can accurately differentiate the diagnosis of postoperative anastomotic recurrence and inflammation of gastric cancer and esophageal cancer and has the potential to be an effective monitoring method for patients with upper digestive tract tumors after surgical treatment.

Technetium-99m-methylene diphosphonate single photon emission computed tomography/computed tomography combined with prostate-specific antigen/free prostate-specific antigen ratio for bone metastasis of prostate cancer

BACKGROUND Prostate cancer(PC)is one of the most common malignant tumors in men,and bone metastasis is one of its common complications,which seriously affects the quality of life and prognosis of patients.AIM To investigate the diagnostic value of technetium-99m-methylene diphosphonate(99mTc-MDP)single photon emission computed tomography(SPECT)/CT imaging combined with the serum prostate-specific antigen(PSA)/free PSA ratio for PC bone metastasis(PCBM).METHODS One hundred patients with PC who visited the Hospital of Chengdu University of Traditional Chinese Medicine from January 2020 to January 2022 were recruited as the experimental(Exp)group,while 30 patients with benign prostatic lesions(BPLs)were recruited as the control(Ctrl)group.All patients underwent 99mTc-MDP SPECT/CT imaging and serum PSA/fPSA testing.The SPECT/CT imaging results and serum PSA/fPSA ratios of patients were analyzed to evaluate their diagnostic values for PCBM.RESULTS The difference in general information of the patients was not obvious,showing comparability.The two methods showed no visible differences in negative predictive value and sensitivity for patients with PCBM,but had great differences in positive predictive value and specificity(P<0.05).The PSA/fPSA ratio of patients with PC in the Exp group was lower than those with BPLs,and patients with PCBM had a much lower PSA/fPSA ratio than those without PC(P<0.05).The results confirmed that the combined use of 99mTc-MDP SPECT/CT imaging and serum PSA/fPSA ratio achieved a detection rate of 95%for PCBM.CONCLUSION The combination of 99mTc-MDP SPECT/CT and PSA/fPSA ratio is accurate and reliable for the diagnosis of PCBM,which provides an important reference for clinical practice.

^(18)F-Fluorodeoxyglucose positron emission tomography/computed tomography comparison of gastric lymphoma and gastric carcinoma

AIM To compare ^(18)F-fluorodeoxyglucose positron emission tomography/computed tomography(^(18)F-FDG PET/CT) features in gastric lymphoma and gastric carcinoma.METHODS Patients with newly diagnosed gastric lymphoma or gastric carcinoma who underwent ^(18)F-FDG PET/CT prior to treatment were included in this study. We reviewed and analyzed the PET/CT features of gastric wall lesions,including FDG avidity,pattern(focal/diffuse),and intensity [maximal standard uptake value:(SUVmax)]. The correlation of SUVmax with gastricclinicopathological variables was investigated by χ~2 test,and receiver-operating characteristic(ROC) curve analysis was performed to determine the differential diagnostic value of SUVmax-associated parameters in gastric lymphoma and gastric carcinoma. RESULTS Fifty-two patients with gastric lymphoma and 73 with gastric carcinoma were included in this study. Abnormal gastric FDG accumulation was found in 49 patients(94.23%) with gastric lymphoma and 65 patients(89.04%) with gastric carcinoma. Gastric lymphoma patients predominantly presented with type Ⅰ and type Ⅱ lesions,whereas gastric carcinoma patients mainly had type Ⅲ lesions. The SUVmax(13.39 ± 9.24 vs 8.35 ± 5.80,P < 0.001) and SUVmax/THKmax(maximal thickness)(7.96 ± 4.02 vs 4.88 ± 3.32,P < 0.001) were both higher in patients with gastric lymphoma compared with gastric carcinoma. ROC curve analysis suggested a better performance of SUVmax/THKmax in the evaluation of gastric lesions between gastric lymphoma and gastric carcinoma in comparison with that of SUVmax alone.CONCLUSION PET/CT features differ between gastric lymphoma and carcinoma,which can improve PET/CT evaluation of gastric wall lesions and help differentiate gastric lymphoma from gastric carcinoma.

Clinical role of (18)~F-fluorodeoxyglucose positron emission tomography/computed tomography in post-operative follow up of gastric cancer: Initial results

AIM: To evaluate the clinical role of 18F-fluorodeo-xyglucose positron emission and computed tomography (18F-FDG PET/CT) in detection of gastric cancer recurrence after initial surgical resection. METHODS: In the period from January 2007 to May 2008, 23 patients who had previous surgical resection of histopathologically diagnosed gastric cancer underwent a total of 25 18F-FDG PET/CT scans as follow-up visits in our center. The standard of reference for tumor recurrence consisted of histopathologic confirmation or clinical follow-up information for at least 5 mo after PET/CT examinations. RESULTS: PET/CT was positive in 14 patients (61%) and negative in 9 (39%). When correlated with final diagnosis, which was confirmed by histopathologic evidence of tumor recurrence in 8 of the 23 patients (35%) and by clinical follow-up in 15 (65%), PET/CT was true positive in 12 patients, false positive in 2, true negative in 8 and false negative in 2. Overall, the accuracy of PET/CT was 82.6%, the negative predictive value (NPV) was 77.7%, and the positive predictive value (PPV) was 85.7%. The 2 false positive PET/CT findings were actually chronic inflammatory tissue lesions. For the two patients with false negativePET/CT, the f inal diagnosis was recurrence of mucinous adenocarcinoma in the anastomosis in one patient and abdominal wall metastasis in the other. Importantly, PET/CT revealed true-positive findings in 11 (47.8%) patients who had negative or no definite findings by CT. PET/CT revealed extra-abdominal metastases in 7 patients and additional esophageal carcinoma in one patient. Clinical treatment decisions were changed in 7 (30.4%) patients after introducing PET/CT into their conventional post-operative follow-up program. CONCLUSION: Whole body 18F-FDG PET/CT was highly effective in discriminating true recurrence in post-operative patients with gastric cancer and had important impacts on clinical decisions in a considerable portion of patients.

Clinical relevance of fluorodeoxyglucose positron emission tomography/computed tomography and magnifying endoscopy with narrow band imaging in decision-making regarding the treatment strategy for esophageal squamous cell carcinoma

BACKGROUND Recent advances in endoscopic technology,especially magnifying endoscopy with narrow band imaging(ME-NBI)enable us to detect superficial esophageal squamous cell carcinoma(ESCC),but determining the appropriate method of resection,endoscopic resection(ER)vs surgical resection,is often challenging.Recently,several studies have reported that 18F-fluorodeoxyglucose positron emission tomography(FDG-PET)is a useful indicator for decision-making regarding treatment for superficial ESCC.Although,there are not enough reports on association between FDG-PET uptake and clinicopathological characteristics of superficial ESCC.And,there are not enough reports on evaluating the usefulness of combination of FDG-PET and ME-NBI for determining the treatment strategy for superficial ESCC.This study evaluated clinical relevance of FDG-PET and ME-NBI in decision-making regarding the treatment strategy for ESCC.AIM To investigate the association between FDG uptake and the clinicopathological characteristics of superficial ESCC and its usefulness of combination of FDG-PET and ME-NBI for determining the treatment strategy for superficial ESCC.METHODS A database of all patients with superficial ESCC who had undergone both MENBI and FDG-PET for pre-treatment staging at Aichi Cancer Center Hospital between January 2008 and November 2018 was retrospectively analyzed.FDG uptake was defined positive or negative whether the primary lesion was visualized or could be distinguished from the background,or not.The invasion depth of ESCC was classified according to the Japan Esophageal Society.Primary endpoint is to evaluate the association between FDG uptake and clinicopathological characteristics of superficial ESCC.Secondary endpoint is to investigate the efficacy of combination of FDG-PET and ME-NBI for determining the treatment strategy for superficial ESCC.RESULTS A total of 82 lesions in 82 patients were included.FDG-PET showed positive uptake in 29(35.4%)lesions.Univariate analysis showed that uptake of FDG-PET had significant correlations with circumferential extension(P=0.014),pathological depth of tumor invasion(P<0.001),infiltrative growth pattern(P<0.001),histological grade(P=0.002),vascular invasion(P=0.001),and lymphatic invasion(P<0.001).On multivariate analysis,only depth of tumor invasion was independently correlated with FDG-PET/computed tomography visibility(P=0.018).The sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV),and accuracy of Type B2 in ME-NBI for the invasion depth of T1a muscularis mucosae and T1b upper submucosal layer were 68.4%/79.4%/50.0%/89.3%/76.8%,respectively,and those of Type B3 for the depth of T1b middle and deeper submucosal layers(SM2 and SM3)were 46.7%/100%/100%/89.3%/90.2%,respectively.On the other hand,those of FDGPET for SM2 and SM3 were 93.3%/77.6%/48.2%/98.1%/80.5%,respectively,whereas,if the combination of positive FDG uptake and type B2 and B3 was defined as an indicator for radical esophagectomy or definitive chemoradiotherapy,the sensitivity,specificity,PPV,NPV,and accuracy were 78.3%/91.5%/78.3%/91.5%/87.8%,respectively.CONCLUSION FDG uptake was correlated with the invasion depth of superficial ESCC.Combined use of FDG-PET and ME-NBI,especially with the microvascular findings of Type B2 and B3,is useful to determine whether ER is indicated for the lesion.

Early detection of response to imatinib therapy for gastrointestinal stromal tumor by using 18F-FDG-positron emission tomography and computed tomography imaging

A 41-year old female with metastatic gastrointestinal stromal tumor was referred to 18F-FDG-positron emission tomography and computed tomography （PET/CT） scan before and after one-month treatment with imatinib （Glivec, Gleevec, Novartis, Basel, Switzerland）, a tyrosine kinase inhibitor （400 mg/d）. Metabolic response was evaluated before and after one month of therapy. The decrease of the maximum standardised uptake value （SUV） was 79% （from 9.8 to 2.1）. Positron emission tomography demonstrated complete metabolic response after one-month of imatinib treatment. Additionally, the previous lesion was compared with the coronal computerized tomographic image. There was no difference in the size of the tumor before and after therapy according to CT images. However, metabolic activity was inhibited. 18F-FDG-PEr is a valuable method for the detection of response to one-month imatinib treatment in patients with gastrointestinal stromal tumors.

Diagnostic value for extrahepatic metastases of hepatocellular carcinoma in positron emission tomography/computed tomography scan

AIM: To evaluated the value of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) scan in diagnosis of hepatocellular carcinoma (HCC) and extrahepatic metastases. METHODS: A total of 138 patients with HCC who had both conventional imaging modalities and 18F-FDG PET/CT scan done between November 2006 and March 2011 were enrolled. Diagnostic value of each imaging modality for detection of extrahepatic metastases was evaluated. Clinical factors and tumor characteristics including PET imaging were analyzed as indicative factors for metastases by univariate and multivariate methods. RESULTS: The accuracy of chest CT was significantly superior compared with the accuracy of PET imaging for detecting lung metastases. The detection rate of metastatic pulmonary nodule ≥ 1 cm was 12/13 (92.3%), when < 1 cm was 2/10 (20%) in PET imaging. The accuracy of PET imaging was significantly superior compared with the accuracy of bone scan for detecting bone metastases. In multivariate analy- sis, increased tumor size (≥ 5 cm) (P = 0.042) and increased average standardized uptake value (SUV) uptake (P = 0.028) were predictive factors for extrahepatic metastases. Isometabolic HCC in PET imaging was inversely correlated in multivariate analysis (P = 0.035). According to the receiver operating characteristic curve, the optimal cutoff of average SUV to predict extrahepatic metastases was 3.4. CONCLUSION: 18F-FDG PET/CT scan is invaluable for detection of lung metastases larger than 1 cm and bone metastases. Primary HCC having larger than 5 cm and increased average SUV uptake more than 3.4 should be considered for extrahepatic metastases.

Whole Body Positron Emission Tomography/Computed Tomography （PET/CT） in the Evaluation of Ophthalmic Tumors

The clinical value of whole body positron emission tomography/computed tomography （PET/CT） as an imaging tool in diagnosis of ophthalmic tumors was investigated. The retrospective observational case series were performed on the patients with suspected ophthalmic tumors who underwent whole body PET/CT. The golden standard of diagnosis was the final pathological diagnosis or the results of long-term follow-up for patients without surgery/ biopsy. PET/CT findings were compared with the golden standard. The sensitivity, specificity, accuracy an^t positive likelihood ratio of PET/CT in the detection of ophthalmic tumors were calculated. The clinical application of PET/CT in different types of ophthalmic tumors was evaluated. The results showed that 30 patients （18 males and 12 females） with a mean age of 43.0 years （range 4-63 years） were collected. The mean sizes of orbital tumors and intraocular tumors were 26.8 mmxl7.8 mm and 11.2 minx6.1 mm, respectively. The overall sensitivity, specificity, accuracy and positive likelihood ratio of whole body PET/CT in ophthalmic tumors were 76.5%, 71.4%, 75.0% and 2.67, and were 62.5%, 100% and 70.0% in intraocular tumors, and those were 100%, 60.0% and 84.6% in orbital tumors, respectively. PET/CT findings were applied to help make appropriate treatment options in 27 out of 30 patients （90.0%）, and 12 （40.0%） patients changed the treatment strategy. False negative results in 4 cases and false positive results in 2 cases were observed in this series. It was suggested that PET/CT was an effective imaging modality in detecting, diagnosing and developing therapeutic schedule for patients with ophthalmic tumors. It was more sensitive and accurate for detecting orbital tumors than for detecting intraocular tumors.

Mediastinal node staging by positron emission tomographycomputed tomography and selective endoscopic ultrasound with fine needle aspiration for patients with upper gastrointestinal cancer:Results from a regional centre

AIM To investigate the impact of endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA) and positron emission tomography-computed tomography(PET-CT) in the nodal staging of upper gastrointestinal(GI) cancer in a tertiary referral centre.METHODS We performed a retrospective review of prospectively recorded data held on all patients with a diagnosis of upper GI cancer made between January 2009 and December 2015. Only those patients who had both a PET-CT and EUS with FNA sampling of a mediastinal node distant from the primary tumour were included. Using a positive EUS-FNA result as the gold standard for lymph node involvement, the sensitivity, specificity, positive and negative predictive values(PPV and NPV) and accuracy of PET-CT in the staging of mediastinal lymph nodes were calculated. The impact on therapeutic strategy of adding EUS-FNA to PET-CT was assessed.RESULTS One hundred and twenty one patients were included. Sixty nine patients had a diagnosis of oesophageal adenocarcinoma(Thirty one of whom were junctional), forty eight had oesophageal squamous cell carcinoma and four had gastric adenocarcinoma. The FNA results were inadequate in eleven cases and the PET-CT findings were indeterminate in two cases, therefore thirteen patients(10.7%) were excluded from further analysis. There was concordance between PET-CT and EUS-FNA findings in seventy one of the remaining one hundred and eight patients(65.7%). The sensitivity, specificity, PPV and NPV values of PET-CT were 92.5%, 50%, 52.1% and 91.9% respectively. There was discordance between PET-CT and EUS-FNA findings in thirty seven out of one hundred and eight patients(34.3%). MDT discussion led to a radical treatment pathway in twenty seven of these cases, after the final tumour stage was altered as a direct consequence of the EUS-FNA findings. Of these patients, fourteen(51.9%) experienced clinical remission of a median of nine months(range three to forty two months). CONCLUSION EUS-FNA leads to altered staging of upper GI cancer, resulting in more patients receiving radical treatment that would have been the case using PET-CT staging alone.

Incidental focal colorectal ^(18)F-fluorodeoxyglucose uptake on positron emission tomography/computed tomography

AIM: To assess the clinical significance of incidental focal colorectal 18 F-fluorodeoxyglucose ( 18 F-FDG) uptake on 18 F-FDG-positron emission tomography/computed tomography (PET/CT). METHODS: The records of all the cases which had undergone colonoscopy after PET/CT within a two weeks interval were reviewed. Adenomas were considered advanced when they were villous, ≥ 10 mm in size, or had high-grade dysplasia. Colorectal cancers and advanced adenomas are collectively referred to as advanced colorectal neoplasms. Receiver-operating characteristic curve analysis was used to determine thesignificant predictive maximum standardized uptake value (SUVmax) cutoff value for advanced colorectal neoplasms and cancer. RESULTS: Ninety-five colorectal lesions matched the site of incidental focal colorectal 18 F-FDG uptake on PET/CT and 146 did not. Colonoscopy showed advanced colorectal neoplasms corresponding to the site of 18 F-FDG uptake in 49 of the 95 (51.5%) lesions with incidental uptake. Of the lesions without incidental uptake, only 6 of 146 (4.1%) had advanced colorectal neoplasms on colonoscopy, indicating a statistically significant difference between the two groups (P < 0.001). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of incidental focal 18 F-FDG uptake in identifying advanced colorectal neoplasms were 89.1%, 75.3%, 51.6%, 95.9%, and 78.4%, respectively. In detecting only CRC, these values were 89.2%, 69.6%, 34.7%, 97.3%, and 72.6%, respectively. The significant SUVmax cutoff value for advanced colorectal neoplasms (area under the curve 0.755, P < 0.001) was 4.35, with a sensitivity, specificity, PPV, NPV, and accuracy of 75.5%, 65.2%, 69.8%, 71.4% and 70.5%, respectively. For CRC, 5.05 was the significant SUVmax cutoff value (area under the curve 0.817, P < 0.001), with a sensitivity, specificity, PPV, NPV, and accuracy of 84.8%, 71.0%, 80.9%, 89.8%, and 75.8%, respectively. CONCLUSION: The presence of incidental focal colorectal 18 F-FDG uptake on PET/CT with a SUVmax ≥ 4.35 increases the likelihood of an advanced colorectal neoplasm.

Tumor characteristics of ductal carcinoma in situ of breast visualized on [F-18] fluorodeoxyglucose-positron emission tomography/computed tomography: Results from a retrospective study

AIM To clarify clinicopathological features of ductal carcinoma in situ(DCIS) visualized on [F-18] fluorodeoxyglucosepositron emission tomography/computed tomography(FDG-PET/CT).METHODS This study retrospectively reviewed 52 consecutive tumors in 50 patients with pathologically proven pure DCIS who underwent [F-18] FDG-PET/CT before surgery. [F-18] FDG-PET/CT was performed after biopsy in all patients. The mean interval from biopsy to [F-18] FDGPET/CT was 29.2 d. [F-18] FDG uptake by visual analysis and maximum standardized uptake value(SUVmax) was compared with clinicopathological characteristics.RESULTS[F-18] FDG uptake was visualized in 28 lesions(53.8%) and the mean and standard deviation of SUVmax was 1.63 and 0.90. On univariate analysis, visual analysis and the SUVmax were associated with symptomatic presentation(P = 0.012 and 0.002, respectively), palpability(P = 0.030 and 0.024, respectively), use of core-needle biopsy(CNB)(P = 0.023 and 0.012, respectively), ultrasound-guided biopsy(P = 0.040 and 0.006, respectively), enhancing lesion ≥ 20 mm on magnetic resonance imaging(MRI)(P = 0.001 and 0.010, respectively), tumor size ≥ 20 mm on histopathology(P = 0.002 and 0.008, respectively). However, [F-18] FDG uptake parameters were not significantly associated with age, presence of calcification on mammography, mass formation on MRI, presence of comedo necrosis, hormone status(estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2), and nuclear grade. The factors significantly associated with visual analysis and SUVmax were symptomatic presentation(P = 0.019 and 0.001, respectively), use of CNB(P = 0.001 and 0.031, respectively), and enhancing lesion ≥ 20 mm on MRI(P = 0.001 and 0.049, respectively) on multivariate analysis.CONCLUSION Although DCIS of breast is generally non-avid tumor, symptomatic and large tumors(≥ 20 mm) tend to be visualized on [F-18] FDG-PET/CT.

Hepatic adenoma mimicking a metastatic lesion on computed tomography-positron emission tomography scan

Positron emission tomography (PET) using 18F-fluorodeoxyglucose ( 18F-FDG) is an imaging modality which reflects cellular glucose metabolism. Most malignant cells accumulate and trap 18F-FDG, allowing the visualisation of increased uptake. It is hence widely used to differentiate malignant from benign lesions. "False positive" findings of hepatic lesions have been described in certain instances such as hepatic abscesses, but are rare in cases involving hepatocellular adenomas. To our knowledge, there have been only 7 reports in the English literature documenting PET-avid hepatocellular adenomas; 6 of the 7 reports were published in the last 3 years with the first report by Patel et al. We report the case of a 44-year-old Chinese female patient with a history of cervical adenocarcinoma, referred for a hepatic lesion noted on a surveillance computed tomography (CT) scan. A subsequent CT-PET performed showed a hypermetabolic lesion (standardized uptake value 7.9) in segment Ⅳb of the liver. After discussion at a multidisciplinary hepato-pancreato-biliary conference, the consensus was that of a metastatic lesion from her previous cervical adenocarcinoma, and a resection of the hepatic lesion was performed. Histology revealed features consistent with a hepatocyte nuclear factor-1 α inactivated steatotic hepatocellular adenoma.

Nomogram using F-18 fluorodeoxyglucose positron emission tomography/computed tomography for preoperative prediction of lymph node metastasis in gastric cancer

BACKGROUND Lymph node(LN)metastasis is an important prognostic factor in patients with gastric cancer(GC).However,the evaluation of LN metastasis status in the preoperative setting is not accurate.Therefore,precise preoperative prediction of LN metastasis status is crucial for optimal treatment in patients with GC.AIM To develop a preoperative nomogram for LN metastasis using F-18 fluorodeoxyglucose(F-18 FDG)positron emission tomography/computed tomography(PET/CT)and preoperative laboratory test findings in GC.METHODS In this study,the data of 566 GC patients who underwent preoperative F-18 FDG PET/CT and subsequent surgical resection were analyzed.The LN metastasis prediction model was developed in the training cohort and validated in the internal validation cohort.Routine preoperative laboratory tests,including albumin and carbohydrate antigen(CA)19-9 were performed in all patients.Univariate and multivariable logistic regression was performed to validate the preoperative predictive indicators for LN metastasis.RESULTS Of the 566 patients,232(41%)had confirmed histopathologic LN metastasis.Univariate logistic regression revealed that the tumor location,blood hemoglobin,serum albumin levels,neutrophil to lymphocyte ratio,platelet to lymphocyte ratio,CA 19-9,maximum standardized uptake value(SUVmax)of the primary tumor(T_SUVmax),and SUVmax of LN(N_SUVmax)were significantly associated with LN metastasis.In multivariate analysis,T_SUVmax(OR=1.08;95%CI:1.02–1.15;P=0.011)and N_SUVmax(OR=1.49;95%CI:1.19–1.97;P=0.002)were found to be significant predictive factors for LNmetastasis.The LN metastasis prediction model using T_SUVmax,N_SUVmax,serum albumin,and CA 19-9 yielded an area under the curve(AUC)of 0.733(95%CI:0.683–0.784,P=0.025)in the training cohort and AUC of 0.756(95%CI:0.678–0.833,P<0.001)in the test cohort.CONCLUSION T_SUVmax and N_SUVmax measured by preoperative F-18 FDG PET/CT are independent predictive factors for LN metastasis in GC.

Fascioliasis presenting as colon cancer liver metastasis on 18Ffluorodeoxyglucose positron emission tomography/computed tomography: A case report

BACKGROUND Fascioliasis is caused by watercress and similar freshwater plants or drinking water or beverages contaminated with metacercariae. Fascioliasis can radiologically mimic many primary or metastatic liver tumors. Herein, we aimed to present the treatment process of a patient with fascioliasis mimicking colon cancer liver metastasis. CASE SUMMARY A 35-year-old woman who underwent right hemicolectomy due to cecum cancer was referred to our clinic for management of colon cancer liver metastasis. Both computed tomography and 18F-fluorodeoxyglucose positron emission tomography revealed several tumoral lesions localized in the right lobe of the liver. After a 6-course FOLFOX (folinic acid, fluorouracil, oxaliplatin) and bevacizumab regimen, the hypermetabolic state on both liver and abdominal lymph nodes continued, and chemotherapy was extended to a 12-course regimen. The patient was referred to our institute when the liver lesions were detected to be larger on dynamic liver magnetic resonance imaging 6 weeks after completion of chemotherapy. Right hepatectomy was performed, and histopathological examination was compatible with fascioliasis. Fasciola hepatica IgG enzyme-linked immunosorbent assay was positive. The patient was administered two doses of triclabendazole (10 mg/kg/dose) 24 h apart. During the follow-up period, dilatation was detected in the common bile duct, and Fasciola parasites were extracted from the common bile duct by endoscopic retrograde cholangiopancreatography (ERCP). Triclabendazole was administered to the patient after ERCP. CONCLUSION Parasitic diseases, such as those caused by Fasciola hepatica, should be kept in mind in the differential diagnosis of primary or metastatic liver tumors, such as colorectal cancer liver metastasis, in patients living in endemic areas.

Positron emission tomography/computed tomography with ^(18)F-fluorodeoxyglucose identifies tumor growth or thrombosis in the portal vein with hepatocellular carcinoma

Patients suffering from hepatocellular carcinoma (HCC) with tumor thrombus in the portal vein generally have a poor prognosis. Portal vein tumor thrombus must be distinguished from portal vein blood thrombus, and this identification plays a very important role in management of HCC. Conventional imaging modalities have limitations in discrimination of portal vein tumor thrombus. The application of positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) for discrimination between tumor extension and blood thrombus has been reported in few cases of HCC, while portal tumor thrombosis and portal vein clot identified by 18F-FDG PET/CT in HCC patients has not been reported so far. We present two HCC cases, one with portal vein tumor thrombus and one thrombosis who were identified with 18F-FDG PET/CT. This report illustrates the complimentary value of combining the morphological and functional imaging in achieving a correct diagnosis in such clinical situations.

Positron emission tomography and magnetic resonance imaging combined with computed tomography in tumor volume delineation: A case report

BACKGROUND Accurate delineation of the target area for patients with hypopharyngeal cancer is the key to achieving an ideal radiotherapy effect.Since computed tomography(CT)alone can no longer meet the treatment needs,fusing CT images with magnetic resonance imaging(MRI)or positron emission tomography(PET)images can overcome the disadvantages of CT.Herein,we present a clinical case of hypopharyngeal cancer to delineate the tumor volume using combined MRI-CT and PET-CT fusion images to examine if they could accurately cover the tumor volume.CASE SUMMARY A 67-year-old male patient with hypopharyngeal carcinoma could not tolerate chemotherapy and surgery due to complicated health issues such as diabetic nephropathy and other underlying diseases.After multidisciplinary consultations,clinicians eventually agreed to undergo radiotherapy to control the progression of his tumor.He was examined by CT,MRI,and 18-fluorodeoxyglucose-PET for treatment planning,and CT images were fused with PET and MRI images while delineating tumor volume.CONCLUSION The image fusion of MRI-CT and PET-CT has both advantages and disadvantages.Compared with CT images alone,the combination of MRI-CT and PET-CT fusion images can precisely cover the gross tumor volume in hypopharyngeal carcinoma and avoid overestimation or incomplete coverage of tumor volume.

Evaluation of recurrence in gastric carcinoma: Comparison of contrast-enhanced computed tomography and positron emission tomography/computed tomography

AIM To compare the value of contrast-enhanced abdominal computed tomography(CT) and fluorodeoxyglucose(FDG) positron emission tomography/computed tomography(PET/CT) for detecting gastric carcinoma recurrence.METHODS We retrospectively examined data from 2475 patients who underwent both contrast-enhanced abdominal CT and FDG PET/CT for the surveillance of gastric carcinoma curative resection. Patients had an interval of less than 1 mo between their CT and PET/CT scans. Sixty patients who had recurrence were enrolled. Among 1896 patients who did not have recurrence, 60 were selected by simple random sampling. All CT and PET/CT images were reviewed retrospectively by two reviewers blinded to all clinical and pathologic information except curative resection due to gastric carcinoma. RESULTS The pathological stage of the recurrence group was statistically significantly higher than that of the control group(P < 0.001). In the 60 patients who had recurrence, there were 79 recurrent lesions. Fortyfour patients had only one location of recurrence, 13 patients had two locations, and 3 patients had three. In the detection of patient-based overall recurrence, no statistically significant differences existed between the two modalities(P = 0.096). However, for peritoneal carcinomatosis, CT had a statistically significantly higher sensitivity compared to PET/CT(96% vs 50%, P = 0.001). Adenocarcinoma was the most common type of gastric carcinoma. On the pathology-based analysis, CT also had a statistically significantly higher sensitivity compared to PET/CT(98% vs 80%, P = 0.035).CONCLUSION Contrast-enhanced CT was superior to PET/CT in the detection of peritoneal carcinomatosis and pathologic type of adenocarcinoma.