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.

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.

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.

Utility of Preoperative Positron Emission Tomography (PET) in Localizing Perforator Vessels of Anterolateral Thigh Free Flap

Objectives: The anterolateral thigh (ALT) flap is often considered the workhorse in soft tissue reconstruction of head and neck defects secondary to trauma, infection, or tumor resection. Despite its many advantages, ALT flaps have been criticized due to variability in vasculature, which may result in inadequate or non-existent perforators. This retrospective study aims to investigate the utility and validity of positron emission tomography (PET) scan to identify the location and characteristics of perforators to the ALT flap. Methods: We performed a 10-year retrospective review of ALT flaps at our institution to identify patients with preoperative PET scans available for analysis. Three reviewers (attending physician, fellow, and resident) were asked to identify the number, location, and characteristics (myocutaneous versus septocutaneous) of ALT perforators on imaging, and reviewer agreement was assessed. Results were then compared to available operative data. Results: One hundred twenty-one patients were identified who underwent ALT free flap surgery. Thirty-eight preoperative PET scans were identified for review. At least one perforator was identified in 92.1% of scans. Agreement percentages regarding the number of perforators ranged from 53% - 61% whereas agreement regarding the location of a single perforator ranged from 79% - 90%. However, reviewers did not agree regarding the type of perforator, with agreement ranging from 34% - 53%. Poor agreement was observed when compared to intraoperative data, with the number of perforators ranging from 26% - 34% and the type of perforator 11% - 24%. These findings are likely due to insufficient data available in operative reports. Conclusion: Although initial studies suggest that PET scan shows promising evidence to support the capacity to preoperatively identify ALT perforators, future prospective studies are warranted to fully validate these findings.

Appearance of aseptic vascular grafts after endovascular aortic repair on[(18)F]fluorodeoxyglucose positron emission tomography/computed tomography

BACKGROUND Diagnosis of prosthetic vascular graft infection with[(18)F]fluorodeoxyglucose positron emission tomography/computed tomography(18F-FDG PET/CT)allows for early detection of functional changes associated with infection,based on increased glucose utilization by activated macrophages and granulocytes.Aseptic vascular grafts,like all foreign bodies,can stimulate an inflammatory response,which can present as increased activity on 18F-FDG PET/CT.Consequently,distinguishing aseptic inflammation from graft infection,though important,can be difficult.In the case of endovascular aneurysm repair(EVAR),a minimally invasive procedure involving the transfemoral insertion of an endoprosthetic stent graft,the normal postoperative appearance of these grafts on 18F-FDG PET/CT can vary over time,potentially confounding study interpretation.AIM To investigate the visual,semiquantitative,and temporal characteristics of aseptic vascular grafts in patients status post EVAR.METHODS In this observational retrospective cohort study,patients with history of EVAR who underwent 18F-FDG PET/CT for indications other than infection were identified retrospectively.All patients were asymptomatic for graft infection-no abdominal pain,fever of unknown origin,sepsis,or leukocytosis-at the time of imaging and for≥2 mo after each PET/CT.Imaging studies such as CT for each patient were also reviewed,and any patients with suspected or confirmed vascular graft infection were excluded.One hundred two scans performed on 43 patients(34 males;9 females;age=77±8 years at the time of the final PET/CT)were retrospectively reviewed.All 43 patients had an abdominal aortic(AA)vascular graft,40 patients had a right iliac(RI)limb graft,and 41 patients had a left iliac(LI)limb graft.Twentytwo patients had 1 PET/CT and 21 patients had from 2 to 9 PET/CTs.Grafts were imaged between 2 mo to 168 mo(about 14 years)post placement.Eight grafts were imaged within 6 mo of placement,including three that were imaged within three months of placement.The mean interval between graft placement and PET/CT for all 102 scans was 51±39 mo.PET/CT data was reconstructed with region-of-interest analysis of proximal,mid and distal portions of the grafts and background ascending aorta.Maximum standardized uptake value(SUVmax)was recorded for each region.SUVmax-to-background uptake ratios(URs)were calculated.Visual assessment was performed using a 2-pattern grading scale:Diffuse(homogeneous uptake less than liver uptake)and focal(one or more areas of focal uptake in any part of the graft).Statistical analysis was performed.RESULTS In total,there were 306 AA grafts,285 LI grafts,282 RI grafts,and 306 ascending aorta background SUVmax measurements.For all 102 scans,mean SUVmax values for AA grafts were 2.8-3.0 along proximal,mid,and distal segments.Mean SUVmax values for LI grafts and RI grafts were 2.7-2.8.Mean SUVmax values for background were 2.5±0.5.Mean URs were 1.1-1.2.Visual analysis of the scans reflected results of quantitative analysis.On visual inspection,98%revealed diffuse,homogeneous 18F-FDG uptake less than liver.Graft URs and visual pattern categories were significantly associated for AA graft URs(F-ratio=21.5,P<0.001),LI graft URs(F-ratio=20.4,P<0.001),and RI graft URs(F-ratio=30.4,P<0.001).Thus,visual patterns of 18F-FDG uptake corresponded statistically significantly to semiquantitative URs.The age of grafts showing focal patterns was greater than grafts showing diffuse patterns,87±89 vs 50±37 mo,respectively(P=0.02).URs were significantly associated with graft age for AA grafts(r=0.19,P=0.001).URs were also significantly associated with graft age for LI grafts(r=0.25,P<0.0001),and RI grafts(r=0.31,P<0.001).Quartiles of similar numbers of graft(n=25-27)grouped by graft age indicated that URs were significantly higher for 4th quartile vs 2nd quartile URs(F-ratio=19.5,P<0.001).When evaluating URs,graft SUVmax values within 10%-20%of the ascending aorta SUVmax is evident in aseptic grafts,except for grafts in the oldest quartiles.In this study,grafts in the oldest quartiles(>7 years post EVAR)showed SUVmax up to 30%higher than the ascending aorta SUVmax.CONCLUSION Characteristics of an aseptic vascular stent graft in the aorta and iliac vessels on 18F-FDG PET/CT include graft SUVmax values within 10%-20%of the ascending aorta background SUVmax.The SUVmax of older aseptic grafts can be as much as 30%above background.The visual uptake pattern of diffuse,homogeneous uptake less than liver was seen in 98%of aseptic vascular grafts,making this pattern particularly reassuring for clinicians.

Polyarteritis nodosa presenting as leg pain with resolution of positron emission tomography-images:A case report

BACKGROUND Although fluorodeoxyglucose-positron emission tomography/computed tomography(FDG-PET/CT)is widely used for diagnosis and follow-up of large sized vessel vasculitis,it is still not widely used for small to medium sized vessel vasculitis.CASE SUMMARY This is the case of a 68-year-old male who presented at the emergency department complaining of fever,myalgia,and bilateral leg pain of over two weeks duration,with elevated levels of C-reactive protein.He was subsequently admitted and despite the absence of clinically significant findings,the patient continued to exhibit recurrent fever.A fever of unknown origin workup,which included imaging studies using FDG-PET/CT,revealed vasculitis involving small to medium-sized vessels of both lower extremities,demonstrated by linear hypermetabolism throughout the leg muscles.The patient was treated with methylprednisolone and methotrexate after diagnosis leading to the gradual resolution of the patient’s symptoms.Three weeks later,a follow-up FDGPET/CT was performed.Previously hypermetabolic vessels were markedly improved.CONCLUSION Our case report demonstrated that FDG-PET/CT has tremendous potential to detect medium-sized vessel inflammation;it can also play a crucial role in prognosticating outcomes and monitoring therapeutic efficacy.

Evaluation of response to gemcitabine plus cisplatin-based chemotherapy using positron emission computed tomography for metastatic bladder cancer

BACKGROUND The purpose of the present study was to examine retrospectively the contribution of 18Fluorodeoxyglucose positron emission tomography computed tomography(18FDG-PET/CT)to the evaluation of response to first-line gemcitabine plus cispla-tin-based chemotherapy in patients with metastatic bladder cancer.AIM To evaluate the response to Gemcitabine plus Cisplatin-based chemotherapy using 18FDG-PET/CT imaging in patients with metastatic bladder cancer.METHODS Between July 2007 and April 2019,79 patients underwent 18FDG-PET/CT imaging with the diagnosis of Metastatic Bladder Carcinoma(M-BCa).A total of 42 pa-tients(38 male,4 female)were included in the study,and all had been admi-nistered Gemcitabine plus Cisplatin-based chemotherapy.After completion of the therapy,the patients underwent a repeat 18FDG-PET/CT scan and the results were compared with the PET/CT findings before chemotherapy according to European Organisation for the Research and treatment of cancer criteria.Mean age was 66.1 years and standard deviation was 10.7 years(range:41–84 years).RESULTS Of the patients,seven(16.6%)were in complete remission,17(40.5%)were in partial remission,six(14.3%)had a stable disease,and 12(28.6%)had a pro-gressive disease.The overall response rate was 57.1 percent.CONCLUSION 18FDG-PET/CT can be considered as a successful imaging tool in evaluating response to first-line chemotherapy for metastatic bladder cancer.Anatomical and functional data obtained from PET/CT scans may be useful in the planning of secondline and thirdline chemotherapy.

Impact of random and scattered coincidences from outside of field of view on positron emission tomography/computed tomography imaging with different reconstruction protocols

Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outside the field of view(FOV)on PET image quality for different reconstruction protocols.Imaging was performed on the Discovery 690 PET/CT scanner,using experimental configurations including the NEMA phantom(a body phantom,with six spheres of different sizes)with a signal background ratio of 4:1.The NEMA phantom(phantom I)was scanned separately in a one-bed position.To simulate the effect of random and scatter coincidences from outside the FOV,six cylindrical phantoms with various diameters were added to the NEMA phantom(phantom II).The 18 emission datasets with mean intervals of 15 min were acquired(3 min/scan).The emission data were reconstructed using different techniques.The image quality parameters were evaluated by both phantoms.Variations in the signal-to-noise ratio(SNR)in a 28-mm(10-mm)sphere of phantom II were 37.9%(86.5%)for ordered-subset expectation maximization(OSEM-only),36.8%(81.5%)for point spread function(PSF),32.7%(80.7%)for time of flight(TOF),and 31.5%(77.8%)for OSEM+PSF+TOF,respectively,indicating that OSEM+PSF+TOF reconstruction had the lowest noise levels and lowest coefficient of variation(COV)values.Random and scatter coincidences from outside the FOV induced lower SNR,lower contrast,and higher COV values,indicating image deterioration and significantly impacting smaller sphere sizes.Amongst reconstruction protocols,OSEM+PSF+TOF and OSEM+PSF showed higher contrast values for sphere sizes of 22,28,and 37 mm and higher contrast recovery coefficient values for smaller sphere sizes of 10 and 13 mm.

Role of 18F-fluorodeoxyglucose positron emission tomography imaging in surgery for pancreatic cancer

AIM： To evaluate the role of positron emission tomography using 18F-fluorodeoxyglucose （FDG-PET） in the surgical management of patients with pancreatic cancer, including the diagnosis, staging, and selection of patients for the subsequent surgical treatment. METHODS： This study involved 53 patients with proven primary pancreatic cancer. The sensitivity of diagnosing the primary cancer was examined for FDG-PET CT, cytological examination of the bile or pancreatic juice, and the serum levels of carcinoembrionic antigens （CEA） and carbohydrate antigen 19-9 （CA29-9）. Next, the accuracy of staging was compared between FDG-PET and CT. Finally, FDG-PET was analyzed semiquantitatively using the standard uptake value （SUV）. The impact of the SUV on patient management was evaluated by examining the correlations between the SUV and the histological findings of cancer. RESULTS： The sensitivity of FDG-PET, CT, cytological examination of the bile or pancreatic juice, and the serum levels of CEA and CA19-9 were 92.5%, 88.7%, 46.4%, 37.7% and 69.8%, respectively. In staging, FDG-PET was superior to CT only in diagnosing distant disease （bone metastasis）. For local staging, the sensitivity of CT was better than that of FDG-PEr. The SUV did not correlate with the pTNM stage, grades, invasions to the vessels and nerve, or with the size of the tumor. However, there was a statistically significant difference （4.6 ± 2.9 vs 7.8 ± 4.5, P = 0.024） in the SUV between patients with respectable and unresectable disease. CONCLUSION： FDG-PET is thus considered to be useful in the diagnosis of pancreatic cancer. However, regarding the staging of the disease, FDG-PET is not considered to be a sufficiently accurate diagnostic modality. Although the SUV does not correlate with the patho-histological prognostic factors, it may be useful in selecting patients who should undergo subsequent surgical treatment.

Utility of positron emission tomography-magnetic resonance imaging in musculoskeletal imaging

Differentiation between neoplastic and nonneoplastic conditions magnetic resonance imaging(MRI) has established itself as one of the key clinical tools in evaluation of musculoskeletal pathology. However, MRI still has several key limitations which require supplemental information from additional modalities to complete evaluation of various disorders. This has led to the development hybrid positron emission tomography(PET)-MRI which is rapidly evolving to address key clinical questions by using the morphological strengths of MRI and functional information of PET imaging. In this article, we aim to review physical principles and techniques of PET-MRI and discuss clinical utility of functional information obtained from PET imaging and structural information obtained from MRI imaging for the evaluation of musculoskeletal pathology. More specifically, this review highlights the role of PET-MRI in musculoskeletal oncology including initial diagnosis and staging, treatment planning and posttreatment follow-up. Also we will review utility of PET-MRI in evaluating musculoskeletal infections(especially in the immunocompromised and diabetics) and inflammatory condition. Additionally, common pitfalls of PET-MRI will be addressed.

^(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 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.

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.

Prognostic value of pre-and post-transplantation 18F-fluorodeoxyglucose positron emission tomography results in non-Hodgkin lymphoma patients receiving autologous stem cell transplantation

Objective： High-dose chemotherapy （HDC） followed by autologous stem cell transplantation （ASCT） is the standard of care in the upfront or relapsed/refractory setting in some patients with non-Hodgkin lymphoma （NHL）. However, a proportion of patients do not respond to ASCT. lSF-fluorodeoxyglueose （FDG） positron emission tomography （PET）/computed tomography （CT） has been widely used for staging, response evaluation, and prognosis prediction. Here, we investigated the prognostic role of PET/CT in NHL patients before and after ASCT. Methods： A retrospective study was conducted at Peking University Cancer Hospital. All NHL patients who underwent ASCT between March 2010 and July 2016 were identified. Patients who had PET/CT scan before and after ASCT were included. Deauville criteria （5-point scale） were used to interpret PET scans. Univariate and multivariate survival analyses were performed using Cox regression. The predictive value of PET scanning was estimated by comparing the area under the receiver operating characteristic （ROC） curve. Results： In total, 79 patients were enrolled in this study. In univariate analysis, pre- and post-ASCT PET result was identified as prognostic factors for 3-year progression-free survival （PFS） and overall survival （OS）. Patients with negative pre-ASCT PET result demonstrated significantly better PFS （84.2% vs. 54.2%） and OS （89.2% vs. 63.6%） than patients with positive pre-ASCT PET result. PFS （91.6% vs. 25.3%） and OS （96.5% vs. 36.8%） were also significantly different between patients with negative and positive post-ASCT PET result. Multivariate analysis also showed a significant association between survival and post-ASCT PET result. ROC analysis revealed that the predictive value of post-ASCT PET result was superior to that of pre-ASCT PET result alone. Combined pre- and post-ASCT PET result is better for predicting outcomes in patients with NHL receiving transplantation. Deauville criteria score 〉3 was identified as the best cutoffvalue for post-ASCT PET. Conclusions： Post-ASCT PET result was more important than pre-ASCT PET result in predicting outcomes for NHL patients who underwent ASCT. The prognostic significance can be improved when combining pre- ASCT PET result with post-ASCT PET result. Deauville criteria can be used for interpreting PET scans in this scenario.

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.

Diagnostic role of 18F-fluorodeoxyglucose positron emission tomography for follicular lymphoma with gastrointestinal involvement

AIM:To investigate the capacity for 18F-fluorodeoxyglucose(18F-FDG) positron emission tomography(PET) to evaluate patients with gastrointestinal lesions of follicular lymphoma.METHODS:This retrospective case series consisted of 41 patients with follicular lymphoma and gastrointestinal involvement who underwent 18F-FDG-PET and endoscopic evaluations at ten different institutions between November 1996 and October 2011.Data for endoscopic,radiological,and biological examinations performed were retrospectively reviewed from clinical records.A semi-quantitative analysis of 18F-FDG uptake was performed for each involved area by calculating the maximum standardized uptake value(SUVmax).Based on the positivity of 18F-FDG uptake in the gastrointestinal lesions analyzed,patients were subdivided into two groups.To identify potential predictive factors for 18F-FDG positivity,these two groups were compared with respect to gender,age at diagnosis of lymphoma,histopathological grade,pattern of follicular dendritic cells,mitotic rate,clinical stage,soluble interleukin-2 receptor levels detected by 18F-FDG-PET,lactate dehydrogenase(LDH) levels,hemoglobin levels,bone marrow involvement,detectability of gastrointestinal lesions by computed tomography(CT) scanning,and follicular lymphoma international prognostic index(FLIPI) risk.RESULTS:Involvement of follicular lymphoma in the stomach,duodenum,jejunum,ileum,cecum,colon,and rectum was identified in 1,34,6,3,2,3,and 6 patients,respectively.No patient had esophageal involvement.In total,19/41(46.3%) patients exhibited true-positive 18F-FDG uptake in the lesions present in their gastrointestinal tract.In contrast,false-negative 18F-FDG uptake was detected in 24 patients(58.5%),while false-positive 18F-FDG uptake was detected in 5 patients(12.2%).In the former case,2/19 patients had both 18F-FDG-positive lesions and 18F-FDGnegative lesions in the gastrointestinal tract.In patients with 18F-FDG avidity,the SUVmax value of the involved gastrointestinal tract ranged from 2.6 to 17.4(median:4.7).For the 18F-FDG-negative(n = 22) and-positive(n = 19) groups,there were no differences in the male to female ratios(10/12 vs 4/15,P = 0.186),patient age(63.6 ± 2.4 years vs 60.1 ± 2.6 years,P = 0.323),presence of histopathological grade 1 vs 2(20/2 and 17/2,P = 1.000),follicular dendritic cell pattern(duodenal/nodal:13/5 vs 10/3,P = 1.000),mitotic rate(low/partly high,14/1 vs 10/3,P = 0.311),clinical stage according to the Ann Arbor system(stages ⅠE and ⅡE/other,15/7 vs 15/4,P = 0.499),clinical stage according to the Lugano system(stages Ⅰ and Ⅱ-1/other,14/8 vs 14/5,P = 0.489),soluble interleukin-2 receptor levels(495 ± 78 vs 402 ± 83,P = 0.884),LDH levels(188 ± 7 vs 183 ± 8,P = 0.749),hemoglobin levels(13.5 ± 0.3 vs 12.8 ± 0.4,P = 0.197),bone marrow involvement(positive/negative,1/8 vs 1/10,P = 1.000),detectability by CT scanning(positive/negative,1/16 vs 4/13,P = 0.335),and FLIPI risk(low risk/other,16/6 vs 13/6,P = 0.763),respectively in each case.CONCLUSION:These findings indicate that it is not feasible to predict 18F-FDG-avidity.Therefore,18FFDG-PET scans represent a complementary modality for the detection of gastrointestinal involvements in follicular lymphoma patients,and surveillance of the entire gastrointestinal tract by endoscopic examinations is required.

Clinical significance of prostate 18F-labelled fluorodeoxyglucose uptake on positron emission tomography/computed tomography:A five-year review

AIM To determine the significance and need for investigation of incidental prostatic uptake in men undergoing ^(18)F-labelled fluorodeoxyglucose(^(18)F-FDG) positron emission tomography/computed tomography(PET/CT) for other indications.METHODS Hospital databases were searched over a 5-year period for patients undergoing both PET/CT and prostate magnetic resonance imaging(MRI). For the initial analysis, the prostate was divided into six sectors and suspicious or malignant sectors were identified using MRI and histopathology reports respectively. Maximum and mean ^(18)F-FDG standardised uptake values were measured in each sector by an investigator blinded to the MRI and histopathology findings. Two agematched controls were selected per case. Results were analysed using a paired t-test and one-way ANOVA. For the second analysis, PET/CT reports were searched for prostatic uptake reported incidentally and these patients were followed up. RESULTS Over a 5-year period, 15 patients underwent both PET/CT and MRI and had biopsy-proven prostate cancer.Malignant prostatic sectors had a trend to higher ^(18)F-FDG uptake than benign sectors, however this was neither clinically nor statistically significant(3.13 ±0.58 vs 2.86 ± 0.68, P > 0.05). ^(18)F-FDG uptake showed no correlation with the presence or histopathological grade of tumour. ^(18)F-FDG uptake in cases with prostate cancer was comparable to that from age-matched controls. Forty-six(1.6%) of 2846 PET/CTs over a 5-year period reported incidental prostatic uptake. Of these, 18(0.6%) were investigated by PSA, 9(0.3%)were referred to urology, with 3(0.1%) undergoing MRI and/or biopsy. No cases of prostate cancer were diagnosed in patients with incidental ^(18)F-FDG uptake in our institute over a 5-year period.CONCLUSION ^(18)F-FDG uptake overlaps significantly between malignant and benign prostatic conditions. Subsequent patient management was not affected by the reporting of incidental focal prostatic uptake in this cohort.

Congenital hyperinsulinism:Role of fluorine-18L-3, 4 hydroxyphenylalanine positron emission tomography scanning

Congenital hyperinsulinism(CHI) is a rare but complex heterogeneous disorder caused by unregulated secre-tion of insulin from the β-cells of the pancreas leading to severe hypoglycaemia and neuroglycopaenia. Swift diagnosis and institution of appropriate management is crucial to prevent or minimise adverse neurodevel-opmental outcome in children with CHI. Histologically there are two major subtypes of CHI, diffuse and focal disease and the management approach will significantly differ depending on the type of the lesion. Patients with medically unresponsive diffuse disease require a near total pancreatectomy, which then leads on to the de-velopment of iatrogenic diabetes mellitus and pancre-atic exocrine insufficiency. However patients with focaldisease only require a limited pancreatectomy to re-move only the focal lesion thus providing complete cure to the patient. Hence the preoperative differentiation of the histological subtypes of CHI becomes paramount in the management of CHI. Fluorine-18L-3, 4-hydroxy-phenylalanine positron emission tomography(18F-DOPA-PET) is now the gold standard for pre-operative differentiation of focal from diffuse disease and locali-sation of the focal lesion. The aim of this review article is to give a clinical overview of CHI, then review the role of dopamine in β-cell physiology and finally discuss the role of 18F-DOPA-PET imaging in the management of CHI.

Comparisons between glucose analogue 2-deoxy-2-(^(18)F)fluoro-D-glucose and ^(18)F-sodium fluoride positron emission tomography/computed tomography in breast cancer patients with bone lesions

AIM: To compare 2-deoxy-2-(18F)fluoro-D-glucose(18F-FDG) and 18F-sodium (18F-NaF) positron emission tomography/computed tomography (PET/CT) accuracy in breast cancer patients with clinically/radiologically suspected or known bone metastases.METHODS: A total of 45 consecutive patients with breast cancer and the presence or clinical/biochemical or radiological suspicion of bone metastatic disease underwent 18F-FDG and 18F-fluoride PET/CT. Imaging results were compared with histopathology when available, or clinical and radiological follow-up of at least 1 year. For each technique we calculated: Sensitivity (Se), specificity (Sp), overall accuracy, positive and negative predictive values, error rate, and Youden’s index. McNemar’s χ2 test was used to test the difference in sensitivity and specificity between the two diagnostic methods. All analyses were computed on a patient basis, and then on a lesion basis, with consideration ofthe density of independent lesions on the co-registered CT (sclerotic, lytic, mixed, no-lesions) and the divergent site of disease (skull, spine, ribs, extremities, pelvis). The impact of adding 18F-NaF PET/CT to the work-up of patients was also measured in terms of change in their management due to 18F-NaF PET/CT findings.RESULTS: The two imaging methods of 18F-FDG and 18F-fluoride PET/CT were significantly different at the patient-based analysis: Accuracy was 86.7% and 84.4%, respectively (McNemar’s χ2 = 6.23, df = 1, P = 0.01). Overall, 244 bone lesions were detected in our analysis. The overall accuracy of the two methods was significantly different at lesion-based analysis (McNemar’s χ2 = 93.4, df = 1, P < 0.0001). In the lesion density-based and site-based analysis, 18F-FDG PET/CT provided more accurate results in the detection of CT-negative metastasis (P < 0.002) and vertebral localizations (P < 0.002); 18F-NaF PET/CT was more accurate in detecting sclerotic (P < 0.005) and rib lesions (P < 0.04). 18F-NaF PET/CT led to a change of management in 3 of the 45 patients (6.6%) by revealing findings that were not detected at 18F-FDG PET/CT.CONCLUSION: 18F-FDG PET/CT is a reliable imaging tool in the detection of bone metastasis in most cases, with a diagnostic accuracy that is slightly, but significantly, superior to that of 18F-NaF PET/CT in the general population of breast cancer patients. However, the extremely high sensitivity of 18F-fluoride PET/CT can exploit its diagnostic potential in specific clinical settings (i.e., small CT-evident sclerotic lesions, high clinical suspicious of relapse, and negative 18F-FDG PET and conventional imaging).

Characterization of focal hypermetabolic thyroid incidentaloma: An analysis with F-18 fluorodeoxyglucose positron emission tomography/computed tomography parameters

BACKGROUND Incidentally found thyroid tumor(thyroid incidentaloma,TI)on F-18 fluorodeoxyglucose(FDG)positron emission tomography-computed tomography(PETCT)is reported in 2.5%-5%of patients being investigated for non-thyroid purposes.Up to 50%of these cases have been diagnosed to be malignant by cytological/histological results.Ultrasonography(US)and fine-needle aspiration cytology are recommended for thyroid nodules with high FDG uptake(hypermetabolism)that are 1 cm or greater in size.It is important to accurately determine whether a suspicious hypermetabolic TI is malignant or benign.AIM To distinguish malignant hypermetabolic TIs from benign disease by analyzing F-18 FDG PET-CT parameters and to identify a cut-off value.METHODS Totally,12761 images of patients who underwent F-18 FDG PET-CT for nonthyroid purposes at our hospital between January 2016 and December 2020 were retrospectively reviewed,and 339 patients[185 men(mean age:68±11.2)and 154 women(mean age:63±15.0)]were found to have abnormal,either focal or diffuse,thyroid FDG uptake.After a thorough review of their medical records,US,and cytological/histological reports,46 eligible patients with focal hypermetabolic TI were included in this study.The TIs were categorized as malignant and benign according to the cytological/histological reports,and four PET parameters[standardized uptake value(SUV)max,SUV_(peak),SUV_(mean),and metabolic tumor volume(MTV)]were measured on FDG PET-CT.Total lesion glycolysis(TLG)was calculated by multiplying the SUV_(mean) by MTV.Both parametric and non-parametric methods were used to compare the five parameters between malignant and benign lesions.Receiver operating characteristic(ROC)curve analysis was performed to identify a cut-off value.RESULTS Each of the 46 patients[12 men(26.1%;mean age:62±13.1 years)and 34 women(73.9%;mean age:60±12.0 years)]with focal hypermetabolic TIs had one focal hypermetabolic TI.Among them,26(56.5%)were malignant and 20(43.5%)were benign.SUV_(max),SUV_(peak),SUV_(mean),and TLG were all higher in malignant lesions than benign ones,but the difference was statistically significant(P=0.012)only for SUV_(max).There was a positive linear correlation(r=0.339)between SUV_(max) and the diagnosis of malignancy.ROC curve analysis for SUV_(max) revealed an area under the curve of 0.702(P<0.05,95%confidence interval:0.550-0.855)and SUV_(max) cut-off of 8.5 with a sensitivity of 0.615 and a specificity of 0.789.CONCLUSION More than half of focal hypermetabolic TIs on F-18 FDG PET-CT were revealed as malignant lesions,and SUV_(max) was the best parameter for discriminating between malignant and benign disease.Unexpected focal hypermetabolic TIs with the SUV_(max) above the cut-off value of 8.5 may have a greater than 70%chance of malignancy;therefore,further active assessment is required.