Clinical implication of FDG uptake of bone marrow on PET/CT in gastric cancer patients with surgical resection

AIM To determine the relationship between F-18 fluorodeoxyglucose(FDG) uptake of bone marrow(BM) on positron emission tomography/computed tomography(PET/CT) and clinical factors and to assess the prognostic value of FDG uptake of BM in gastric carcinoma.METHODS We retrospectively enrolled 309 gastric cancer patients who underwent staging FDG PET/CT and curative surgical resection. FDG uptake of primary tumor was visually classified as positive or negative FDG uptake. Mean FDG uptake of BM(BM SUV) and BM-to-liver uptake ratio(BLR) were measured. The relationships of BM SUV or BLR with clinical factors were evaluated. The prognostic values of BM SUV, BLR, and other clinical factors for predicting recurrence-free survival(RFS) and overall survival(OS) were assessed.RESULTS Of 309 patients, 38 patients(12.3%) experienced cancer recurrence and 18 patients(5.8%) died. Patients with advanced gastric cancer, positive FDG uptake, and recurrence had higher values of BM SUV and BLR than those with early gastric cancer, negative FDG uptake, and no recurrence(P 0.05). BM SUV and BLR were significantly correlated with hemoglobin level, neutrophil-to-lymphocyte ratio, and platelet-tolymphocyte ratio(P 0.05). On multivariate analysis, multiple tumors, T stage, lymph node metastasis, tumor involvement of resection margin, and BLR were significantly associated with RFS(P 0.05). T stage, lymph node metastasis, hemoglobin level, and BLR were significantly associated with OS(P 0.05). CONCLUSION BLR on PET/CT was an independent prognostic factor for RFS and OS in gastric cancer patients with curative surgical resection.     

Clinical role of 18F-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.     

Surgical management of patients with bowel obstructions secondary to gastric cancer

AIM: To assess whole-body fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the management of small bowel obstructions (SBOs) secondary to gastric cancer and its role in treatment strategies. METHODS: The medical records of all of the patients who were admitted for an intestinal obstruction after curative resection for gastric cancer were retrospectively reviewed. PET/CT was performed before a clinical treatment strategy was established for each patient. The patients were divided into 2 groups: patients with no evidence of a tumor recurrence and patients with evidence of a tumor recurrence. Tumor recurrences included a local recurrence, peritoneal carcinomatosis or distant metastases. The primary endpoint was the 1-year survival rate, and other variables included patient demographics, the length of hospital stay, complications, and mortality. RESULTS: The median time between a diagnosis of gastric cancer and the detection of a SBO was 1.4 years. Overall, 31 of 65 patients (47.7%) had evidence of a tumor recurrence on the PET/CT scan, which was the only factor that was associated with poor survival. Open and close surgery was the main type of surgical procedure reported for the patients with tumor recurrences. R0 resections were performed in 2 patients, including 1 who underwent combined adjacent organ resection. In the group with no evidence of a tumor recurrence on PET/CT, bowel resections were performed in 7 patients, adhesiolysis was performed in 7 patients, and a bypass was performed in 1 patient. The 1-year survival curves according to PET/CT evidence of a tumor recurrence vs no PET/CT evidence of a tumor recurrence were significantly different, and the 1-year survival rates were 8.8% vs 93.5%, respectively. There were no significant differences (P = 0.71) in the 1-year survival rates based on surgical vs nonsurgical management (0% with nonoperative treatment vs 20% after exploratory laparotomy). CONCLUSION: 18 F-FDG PET/CT can be used to identify the causes of bowel obst     

Comparison of the diagnostic value of 3-deoxy-3-18F-fluorothymidine and 18F-fluorodeoxyglucose positron emission tomography/computed tomography in the assessment of regional lymph node in thoracic esophageal squamous cell carcinoma: a pilot study

We used pathological examination as golden standard to determine whether 3-deoxy-3-(18)F-fluorothymidine positron emission tomography/computed tomography (FLT PET/CT) can detect regional lymph node metastasis in untreated thoracic esophageal squamous cell carcinoma and additionally performed (18)F-fluorodeoxyglucose (FDG) PET/CT for direct comparison with that of FLT. Twenty-two patients with thoracic esophageal squamous cell carcinoma underwent dual-tracer PET/CT examinations before surgery. The results of reviewing CT images and side-by-side FDG PET and FLT PET images for the diagnosis of locoregional lymph node metastasis were compared prospectively in relation to pathologic findings. All patients underwent esophagectomy and lymphadenectomy. Pathologic examination confirmed nodes positive for metastasis in 16 patients and 47 of 424 excised nodes. The uptake of FDG (median SUVmax, 5.4; range, 2.4-10.6) in locoregional lymph nodes metastases was significantly higher than that of FLT (median SUVmax, 2.8; range, 1.3-4.6). There were 14 false-positive nodes in FDG PET/CT and only 3 in FLT PET/CT; 8 false-negative nodes in FDG PET/CT, while there were 12 false negative nodes in FLT PET/CT. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FLT PET/CT were 74.47%, 99.20%, 96.46%, 92.11%, and 96.89%, respectively, whereas those of FDG PET/CT were 82.98%, 96.29%, 94.81%, 82.98%, and 96.29%, respectively. P-values were 0.450, 0.014, 0.313, 0.050, and 0.555, respectively. FLT uptake in regional lymph nodes of esophageal carcinoma is significantly lower compared with FDG uptake. FLT PET/CT has fewer false-positive findings and higher specificity compared with FDG PET/CT.     

Results of radio frequency ablation of primary and secondary liver tumors: long-term follow-up with computed tomography and positron emission tomography-18F-deoxyfluoroglucose scanning

BACKGROUND: In the literature, promising results have been obtained with radiofrequency ablation (RFA) of primary liver malignancies (e.g. hepatocellular carcinoma, HCC) and secondary liver malignancies (e.g. metastases of colorectal tumors). In our center, positron emission tomography with FDG (FDG-PET) and computed tomography (CT) were used for follow-up. Patient outcome was compared with that in the literature, and PET and CT were analyzed regarding positive and negative predictive values for early detection of tumor recurrence. METHODS: The data were analyzed of patients who were treated with RFA for primary or secondary liver tumors between January 1999 and December 2002. Indications for treatment with RFA were liver tumors that could not be resected owing to size, number, or tumor location. In all patients, a CT scan was performed before RFA, and follow-up was performed with a CT scan in all patients and with an additional PET scan at various intervals in 11 patients. At evaluation with PET, tumor recurrence was defined as positive uptake of tracer either at the previous RFA lesion or at a new site in the liver. RESULTS: In total, 15 patients (8 M, 7 F) were treated in 21 sessions with RFA. The mean follow-up period was 16.8 months (range: 7-42). Average age of the patients was 63 years (range: 40-74). One patient had a primary liver tumor; all other patients had metastases of the breast (1), ovary (1), renal cells (1), and colorectal carcinoma (11 patients). The mean number of tumors per patient was 2.7 (range: 1-5). No treatment-related morbidity or mortality occurred. In 4 of 11 patients evaluated with PET at a mean period of 6.8 months, positive uptake of tracer was noted. At CT evaluation, tumor recurrence was observed in 4 of these patients, at a mean time of 9.8 months. Two patients (13.3%) died of cancer recurrence during follow-up. CONCLUSIONS: Tumor recurrence is comparable with that in other studies. Centrally located tumors showed more recurrence than peripheral tumors. The use of PET in combination with CT scan at follow-up may lead to earlier detection of tumor recurrence than contrast-enhanced CT alone.     

Diagnostic and prognostic value of 18-fluorodeoxyglucose positron emission tomography in adrenocortical carcinoma: a prospective comparison with computed tomography

OBJECTIVE: Patients with adrenocortical cancer are submitted to multiple imaging procedures for diagnosis of recurrence and staging. The aim of this prospective study was to evaluate the diagnostic and prognostic values of fluorodeoxyglucose (FDG) using a combined positron emission tomography and computed tomography (PET/CT) modality, compared with thoracoabdominopelvic computed tomography (TAP-CT). METHODS: Twenty-eight consecutive patients with adrenocortical cancer referred from November 2003 to December 2004 to the Institut Gustave Roussy were included. Mean time between PET/CT and TAP-CT was 16 d. Independent readers analyzed images of each modality. The gold standard was progression on follow-up TAP-CT or pathology. RESULTS: A total of 269 lesions in 57 organs were depicted in 22 patients. The sensitivities for the detection of distinct lesions and the diagnosis of metastatic organs were 90 and 93% for PET/CT and 88 and 82% for TAP-CT, respectively. Twelve percent of the lesions were seen on PET/CT only and 10% on TAP-CT only. Eighteen percent of the metastatic organs were diagnosed with PET/CT only and 7% with TAP-CT only. Thirty-eight percent of the local relapses were seen only with PET/CT. PET/CT depicted three false-positive lesions. Treatment modalities were modified by PET/CT findings in five cases among which one was falsely positive. Tumor size and mitotic rate were significantly associated with FDG uptake. The intensity of FDG uptake (maximum standardized uptake value > 10) and the volume of FDG uptake (>150 ml) were significant prognostic factors for survival. CONCLUSIONS: We show that FDG-PET/CT is complementary to TAP-CT and of special interest in the diagnosis of local relapses.     

18FDG-positron emission tomography/computed tomography (PET/CT) scanning in thyroid nodules with nondiagnostic cytology

Objective To assess the role of positron emission tomography/computed tomography (PET/CT) scans with ¹⁸FDG (¹⁸FDG‐PET/CT) in the evaluation of thyroid nodules with nondiagnostic cytology. Subjects and methods Eighty‐eight patients with a single euthyroid nodule and repeatedly nondiagnostic ultrasound‐guided fine‐needle cytology (US‐FNC) were enrolled in the present study. Nodules concentrating ¹⁸FDG were considered positive (i.e. suspicious for malignancy). Histological findings were obtained after surgery in all patients. Results None of 41 patients with negative ¹⁸FDG‐PET/CT scan had a final histological diagnosis of malignancy (i.e. no false‐negative results). Twenty‐nine patients with final histological diagnosis of thyroid cancer had positive ¹⁸FDG‐PET/CT scan. Eighteen patients with final histological diagnosis of benign lesions (including four with follicular adenomas) also had positive ¹⁸FDG‐PET/CT scans. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were 100%, 69%, 79%, 62% and 100%, respectively. Conclusions A negative ¹⁸FDG‐PET/CT scan accurately excludes malignancy in thyroid nodules with non‐diagnostic US‐FNC procedures. Histology is still necessary to distinguish benign from malignant disease in ¹⁸FDG‐PET/CT‐positive nodules, but unnecessary surgery could have been reduced from 88 to 41 cases (46%) in our series.     

Value of positron emission tomography with 18-fluorodeoxyglucose (FDG-PET) in diagnosis of recurrent bronchial carcinoma

The aim of the present investigation was to evaluate the diagnostic accuracy of positron emission tomography with 18-fluoro-2-deoxyglucose (FDG-PET) in the detection of recurrent lung cancer. PET was performed using an ECAT ART scanner (Siemens CTI) after i.v. injection of 220 +/- 50 MBq 18FDG. PET data were analysed by visual interpretation of coronal, sagittal and transversal slices. PET scans were interpreted independently by two experienced nuclear medicine physicians without prior knowledge of the results of other imaging studies or clinical data. 40 patients (= 41 cases) who had undergone primarily curative tumour treatment, were evaluated. In 29 of 35 cases with recurrent tumour, diagnosis was verified by pathologic means. FDG-PET correctly identified tumour recurrence in 34/35 cases. In 5/6 cases without prevent tumour recurrence PET gave true negative results. The overall accuracy of FDG-PET was 39/41 = 95% (95%-confidence interval 83-99%). FDG-PET shows high diagnostic accuracy in detecting recurrent lung cancer in patients with prior curative tumour treatment, but cannot substitute the need for pathological diagnosis.     

Epidermal growth factor receptor antibody plus recombinant human endostatin in treatment of hepatic metastases after remnant gastric cancer resection

We report a 55-year-old male who developed advanced hepatic metastasis and peritoneal carcinomatosis after resection of remnant gastric cancer resection 3 mo ago. The patient only received epidermal growth factor （EGF） receptor antibody （Cetuximab） plus recombinant human endostatin （Endostar）. Anti-tumor activity was assessed by ^18F-fluorodeoxyglucose （^18F-FDG） positron emission tomography/computer tomography （PET/CT） at baseline and then every 4 wk. The case illustrates that ^18FDG-PET/CT could make an early prediction of the response to Cetuximab plus Endostar in such clinical situations. ^18FDG-PET/CT is a useful molecular imaging modality to evaluate the biological response advanced hepatic metastasis and peritoneal carcinomatosis to Cetuximab plus Endostar in patients after remnant gastric cancer resection.     

Clinical value of 18F-fluoro-dexoxyglucose positron emission tomography/computed tomography in patients with adult-onset Still's disease: A seven-case series and review of the literature

Abstract

Objectives. While there are a few reports describing 18F-fluoro-dexoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) findings in patients with adult-onset Still's disease (AOSD), no summary report has yet been published. In this study, we evaluated the usefulness of FDG-PET/CT for diagnosis and activity evaluation in patients with AOSD by summarizing the findings of our patients and those reported in the literature.

Methods. Seven consecutive AOSD patients who had undergone PET/CT at our department between 2007 and 2012 were included. We evaluated FDG uptake for characteristic findings in patients with AOSD. In addition, we reviewed the literature on seven previously reported AOSD patients who had undergone PET/CT.

Results. FDG accumulation was positive mainly in the bone marrow (100%), spleen (90.9%), lymph nodes (80.0%) and joints (75.0%). In addition, FDG uptake was positive in the pericardium, pleura, salivary glands, eyelids, muscle and major blood vessels. Six patients underwent follow-up FDG PET/CT for evaluation of treatment efficacy. Follow-up PET/CT showed diminished FDG accumulation in the bone marrow, spleen and lymph nodes, with maximum standardized uptake value (SUV_max) being substantially reduced from 4.03 ± 0.95 to 2.20 ± 0.75 (p = 0.04), 4.04 ± 1.10 to 2.55 ± 1.13 (p = 0.04) and 5.63 ± 4.99 to 2.10 ± 1.91 (p = 0.11), respectively. No significant correlation was found between SUV_max in each lesion and the laboratory data, except for a significant correlation between lactate dehydrogenase (LDH) and spleen SUV.

Conclusions. FDG-PET/CT is useful for long-term assessments of AOSD activity in individual patients. However, PET/CT findings alone are not sufficient to make a differential diagnosis of AOSD versus malignant lymphoma.     

Postradioiodine treatment whole-body scan in the era of 18-fluorodeoxyglucose positron emission tomography for differentiated thyroid carcinoma with elevated serum thyroglobulin levels

Background: Patients with differentiated thyroid cancer (DTC) who have a suspicious recurrent or persistent disease based on an elevated serum thyroglobulin (Tg) or Tg antibodies (TgAb) are usually referred for empiric radioiodine ((131)I) administration to localize and treat the disease. The aim of this retrospective monocentric study was to assess the sensitivity of postempiric (131)I whole-body scan (WBS) compared to 18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in such patients who had an initial normal postablation WBS. Methods: Among 47 consecutive patients with DTC who had a normal postablation WBS and were referred for empiric (131)I administration, 34 patients (12M, 22F; mean age 53 years) underwent FDG PET/CT and form the basis of this report: 23 patients had persistently elevated serum Tg levels, 10 had elevated Tg levels observed during follow-up after they initially became under 1?ng/mL, and 1 had appearance of TgAb during follow-up. Postempiric (131)I WBS and FDG PET/CT were analyzed by independent readers. Results: A total of 75 lesions were found in 23 patients, distributed in 36 organs. Lesions were located in the neck (30), lungs (28), mediastinum (11), and bones (6). The sensitivities for the detection of individual lesions and for the diagnosis of metastatic organs were 88% and 97% for PET/CT and 16% and 22% for WBS, respectively (p<0.01). PET/CT was abnormal in 22 patients, among which 5 also had an abnormal postempiric (131)I WBS. There was only one patient with an abnormal postempiric (131)I WBS and a normal FDG PET/CT. This patient underwent two further (131)I administrations, with the last WBS being normal and the last stimulated Tg level being undetectable. Other patients were either treated with surgery, or classified as radioactive iodine refractory and treated with levothyroxine suppressive therapy or tyrosine kinase inhibitors. Conclusion: In patients with suspicious recurrence based on the Tg level after a normal postablation WBS, FDG PET/CT is the preferred scintigraphic method to localize disease rather than postempiric (131)I WBS. Empiric (131)I administration may be used only in patients who do not have a significant FDG uptake.     

Positron emission tomography/computer tomography in guidance of extrahepatic hepatocellular carcinoma metastasis management

Hepatocellular carcinoma （HCC） is one of the most common primary cancers in the world. Surgery is the gold standard for treatment of patients with HCC. Recurrence and metastasis are the major obstacles to further improve the prognosis of HCC. Most recurrences are intrahepatic. However, 30% of the recurrences are extrahepatic. The role of resection in intrahepatic recurrences is widely accepted. The role of resection in extrahepatic HCC recurrence and metastasis is not well established. 18F fluorodeoxyglucose （18F-FDG） positron emission tomography/computer tomography （PET/CT） is useful in detecting distant metastasis from a variety of malignancies and shows superior accuracy to conventional imaging modalities in identification of intrahepatic and extrahepatic metastasis. We present one patient with one new isolated omental lymph node metastasis, who had a history of huge HCC resected six years ago. The metastatic focus was identified with 18 F-FDG PET/CT and resected. The follow-up revealed good prognosis with a long-term survival potential after resection of the omental lymphatic metastasis.     

Bone marrow 18F‐fluoro‐2‐deoxy‐d‐glucose positron emission tomography/computed tomography cannot replace bone marrow biopsy in diffuse large B‐cell lymphoma

This study aimed to investigate whether visual and quantitative ¹⁸F‐fluoro‐2‐deoxy‐d ‐glucose positron emission tomography/computed tomography (FDG‐PET/CT)‐based bone marrow assessment can replace blind bone marrow biopsy (BMB) in newly diagnosed diffuse large B‐cell lymphoma (DLBCL). This retrospective study included 78 patients with newly diagnosed DLBCL who had undergone both FDG‐PET/CT and BMB. FDG‐PET/CT images were visually evaluated for bone marrow involvement. Patient‐based sensitivity of visual FDG‐PET/CT assessment was calculated using BMB as the reference standard. Metabolically active volume, maximum standardized uptake value, 3D partial volume corrected mean standardized uptake value, and 3D partial volume corrected mean metabolic volume product (cMVP_mean) of FDG‐avid bone marrow lesions were measured. Cox regression analysis was used to determine the influence of (potential) prognostic factors (BMB status, visual [dichotomous] FDG‐PET/CT bone marrow status, metabolically active volume, maximum standardized uptake value, 3D partial volume corrected mean standardized uptake value, 3D partial volume corrected mean metabolic volume product, and International Prognostic Index score) on progression‐free survival and overall survival. FDG‐PET/CT detected bone marrow involvement in 34 (43.6%) cases and BMB in 16 (20.5%) of 78 cases, of whom 11 were also detected by FDG‐PET/CT, resulting in a patient‐based sensitivity of 68.8% (95% confidence interval = 44.2%–86.1%) for FDG‐PET/CT. In the multivariate Cox proportional hazards model, only BMB status was an independent predictive factor of progression‐free survival (P = 0.016) and overall survival (P = 0.004). In conclusion, FDG‐PET/CT misses bone marrow involvement that has been detected by BMB in a non‐negligible proportion of patients. Furthermore, both visual and quantitative FDG‐PET/CT‐based bone marrow assessments are prognostically inferior to BMB. Therefore, FDG‐PET/CT cannot replace BMB in newly diagnosed DLBCL. Am. J. Hematol. 89:726–731, 2014. © 2014 Wiley Periodicals, Inc.     

Unusual adrenal metastasis and abdominal carcinomatosis secondary to Hurthle cell carcinoma of the thyroid.

Hurthle cell carcinoma (HCC) of the thyroid is an uncommon and relatively rare differentiated thyroid neoplasm. To our knowledge, no reported case of adrenal metastases with abdominal carcinomatosis secondary to HCC of the thyroid has been demonstrated by F-18 FDG PET/CT imaging. One report of adrenal uptake on I-131 whole-body scan with HCC exists. In this case report, we describe a patient with HCC who had a left adrenal metastasis with abdominal carcinomatosis that was discovered using F-18 FDG PET/CT imaging.     

Whole-body fluorodeoxyglucose positron emission tomography/computed tomography in patients with active polymyalgia rheumatica: evidence for distinctive bursitis and large-vessel vasculitis

Objectives

To investigate fluorodeoxyglucose (FDG) accumulation in large joints, bursas, and large vessels in patients with polymyalgia rheumatica (PMR) using 18-FDG positron emission tomography/computed tomography (PET/CT) and to differentiate PMR from similar diseases.

Methods

Fourteen untreated patients with active PMR and 17 control patients with rheumatoid arthritis (n?=?11) or other active rheumatic diseases (n?=?6) underwent 18-FDG PET/CT. FDG uptake in large joints, bursas and vertebral spinous processes was evaluated by calculating maximum standardised uptake values and by visual scoring (scale 0–4). PET scan images were scored in seven vascular regions, and total vascular scores (range 0–21) were calculated.

Results

Polymyalgia rheumatica patients showed increased FDG uptake in ischial tuberosities, greater trochanters, and lumbar spinous processes. Positive results at two or more of these sites showed high sensitivity (85.7%) and specificity (88.2%) for the diagnosis of PMR, and shoulder or hip-joint involvement showed low disease specificity. High FDG accumulations were found in the aortas and subclavian arteries of two PMR patients who were asymptomatic for temporal arteritis and scanty synovium and perisynovium, based on FDG uptake. PET/CT images of the 12 PMR patients without apparent vascular involvement showed synovitis and/or perisynovitis.

Conclusions

Fluorodeoxyglucose-PET/CT may be useful for the detection of PMR lesions, which are difficult to identify using other methods.     

Clinical significance of CT-defined minimal ascites in patients with gastric cancer

AIM: To study the clinical significance of minimal ascites, which was only defined by the CT and whose nature was not determined preoperatively, in the relationship with the peritoneal carcinomatosis. METHODS: The medical records and the dynamic CT films of 118 patients with gastric cancer were reviewed. Factors associated with peritoneal carcinomatosis were analyzed in 40 patients who had CT-defined ascites of which the nature was surgically confirmed. RESULTS: Only 12.5-25% of the CT-defined minimal ascites, whose volume was estimated to be less than 50 mL, were associated with peritoneal carcinomatosis. When the estimated CT-defined ascitic volume was 50 mL or more, peritoneal carcinomatosis was identified in 75-100%. When CT-defined lymph node enlargements were not found beyond the regional gastric area, perigastric invasions were not suspected, and the size of tumor was less than 3 cm, peritoneal carcinomatosis seemed significantly less accompanied at the univariate analysis. However, except for the minimal volume of CT-defined ascites in comparison with the mild or more, other factors were not confirmed multivariately. CONCLUSION: In the patients with gastric cancer, CT-defined minimal ascites alone is rarely associated with peritoneal carcinomatosis, if it does not accompany other signs suggestive of malignant seeding. Therefore, consideration of active curative resection should not be hesitated, if CT-defined minimal ascites is the only delusive sign.     

Whole-body fluorodeoxyglucose positron emission tomography/computed tomography in patients with active polymyalgia rheumatica: evidence for distinctive bursitis and large-vessel vasculitis

Abstract

Objectives To investigate fluorodeoxyglucose (FDG) accumulation in large joints, bursas, and large vessels in patients with polymyalgia rheumatica (PMR) using 18-FDG positron emission tomography/computed tomography (PET/CT) and to differentiate PMR from similar diseases.

Methods Fourteen untreated patients with active PMR and 17 control patients with rheumatoid arthritis (n = 11) or other active rheumatic diseases (n = 6) underwent 18-FDG PET/CT. FDG uptake in large joints, bursas and vertebral spinous processes was evaluated by calculating maximum standardised uptake values and by visual scoring (scale 0–4). PET scan images were scored in seven vascular regions, and total vascular scores (range 0–21) were calculated.

Results Polymyalgia rheumatica patients showed increased FDG uptake in ischial tuberosities, greater trochanters, and lumbar spinous processes. Positive results at two or more of these sites showed high sensitivity (85.7%) and specificity (88.2%) for the diagnosis of PMR, and shoulder or hip-joint involvement showed low disease specificity. High FDG accumulations were found in the aortas and subclavian arteries of two PMR patients who were asymptomatic for temporal arteritis and scanty synovium and perisynovium, based on FDG uptake. PET/CT images of the 12 PMR patients without apparent vascular involvement showed synovitis and/or perisynovitis.

Conclusions Fluorodeoxyglucose-PET/CT may be useful for the detection of PMR lesions, which are difficult to identify using other methods.     

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 analysis, 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.     

Comparison of sestamibi single-photon emission computed tomography with positron emission tomography for estimating left ventricular myocarclial viability

Technetium-99m methoxyisobutyl isonitrile (technetium-99m sestamibi [MIBI]) is distributed in the myocardium according to blood flow. Reports comparing stress rest sestamibi protocols with reinfection thallium or resting fluorodeoxyglucose (FDG), or both, in patients with coronary artery disease have shown appreciable discordance regarding myocardial viability in these settings. We performed this analysis with regard to regional comparisons within discordant segments and made comparisons in a subset of patients who underwent revascularization. Thirty-seven patients with coronary artery disease had single-photon emission computed tomography MIBI, N-13 ammonia/¹⁸FDG positron emission tomography (PET), and radionuclide ventriculography performed at rest. One hundred two segments were viable and 29 were nonviable by both MIBI and FDG. The concordance was 71%. In MIBI nonviable/ FDG viable segments, most of the discordance was in the inferior wall. In MIBI nonviable discordant segments, FDG accurately predicted an increase in percent regional ejection fraction (preoperative 36% [± 5 SE] to postoperative 48% [± 5.5 SE] [p < 0.0006]). MIBI underestimates myocardial viability as assessed by PET. Seventy-one percent of myocardial segments were concordant by both quantitative sestamibi single-photon emission computed tomography and FDG PET. Discordance in MIBI nonviable segments was predominantly in the inferior wall. PET can be helpful in detecting myocardial viability in patients suspected of having had MIBI nonviability in the inferior wall.     

Thyroid-stimulating hormone-stimulated fused positron emission tomography/computed tomography in the evaluation of recurrence in 131I-negative papillary thyroid carcinoma.

Fluorine-18 2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) detects recurrence of papillary thyroid carcinoma (PTC) in thyroidectomized patients with elevated thyroglobulin (Tg) levels and negative (131)I-whole-body scans. This paper describes the utility of thyroid-stimulating hormone (TSH)-stimulated fused FDG-PET/computed tomography (CT) scanning on our first 15 patients of this population. METHODS: Patients were prepared for PET/CT imaging with thyroid hormone withdrawal (n = 7) or recombinant human TSH (n = 8). All other imaging before the PET/CT did not demonstrate evidence of recurrence. RESULTS: PET/CT scans revealed active foci in 9 patients, 4 prepared with hypothyroidism, and 5 with exogenous TSH. Positive results were demonstrated even in those with relatively low stimulated-TSH Tg values (13 and 14 microg/L). Six patients with positive PET/CT scans were treated surgically, yielding malignant tissue for 5 of those patients. CONCLUSION: PET/CT scans performed under TSH stimulation are an effective method of detecting of recurrence of PTC and direct surgical interventions, even in those with persistently elevated but relatively low Tg levels.