Retroperitoneal Bronchogenic Cyst Presenting Paraadrenal Tumor Incidentally Detected by 18F-FDG PET/CT

A follow-up ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET/CT scan of a 57-year-old asymptomatic male who had undergone total thyroidectomy for thyroid cancer revealed a 5.0 × 4.0-cm, well-defined, ovoid-shaped mass around the left adrenal gland without definite FDG uptake. On the adrenal CT scan, the left paraadrenal tumor showed high attenuation on the precontrast scan without enhancement. The average Hounsfield unit (HU) was 58.1 on the precontrast scan and 58.4 on the postcontrast scan. The patient underwent laparoscopic adrenalectomy for resection of the left paraadrenal tumor. The final histopathologic examination revealed a bronchogenic cyst. Although retroperitoneal bronchogenic cysts are rare, they should be considered in the differential diagnosis of retroperitoneal cystic tumors. The preoperative diagnosis is difficult, but a contrast-enhanced CT scan or ¹⁸F-FDG PET/CT scan may be useful for differentiating hyperattenuated cysts from other soft tissue masses.     

Primary Malignant Fibrous Histiocytoma in Mediastinum: Imaging with 18F-FDG PET/CT

Malignant fibrous histiocytoma (MFH) is the most common soft tissue tumor which often occurs in the extremities and the retroperitoneum. Primary mediastinal MFH is rare; thus, findings on ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) of mediastinal MFH have not been reported yet. We report herein the case of a 64-year-old man who was presented with a superior mediastinal mass. The mass showed intense ¹⁸F-FDG uptake with central metabolic defect on PET/CT. The maximum standardized uptake value was 17.4. After tumor removal via median sternotomy, an MFH of the storiform-pleomorphic type was diagnosed on histopathologic examination. We present the first report of ¹⁸F-FDG PET/CT imaging of MFH in the superior mediastinum.     

(18)F-FDG PET versus (18)F-FDG PET/CT for adrenal gland lesion characterization: a comparison of diagnostic efficacy in lung cancer patients.

OBJECTIVE: The aim of this study was to assess the diagnostic efficacy of integrated PET/CT using fluorodeoxyglucose (FDG) for the differentiation of benign and metastatic adrenal gland lesions in patients with lung cancer and to compare the diagnostic efficacy with the use of PET alone. MATERIALS AND METHODS: Sixty-one adrenal lesions (size range, 5-104 mm; mean size, 16 mm) were evaluated retrospectively in 42 lung cancer patients. Both PET images alone and integrated PET/CT images were assessed, respectively, at two-month intervals. PET findings were interpreted as positive if the FDG uptake of adrenal lesions was greater than or equal to that of the liver, and the PET/CT findings were interpreted as positive if an adrenal lesion show attenuation > 10 HU and showed increased FDG uptake. Final diagnoses of adrenal gland lesions were made at clinical follow-up (n = 52) or by a biopsy (n = 9) when available. The diagnostic accuracies of PET and PET/CT for the characterization of adrenal lesions were compared using the McNemar test. RESULTS: Thirty-five (57%) of the 61 adrenal lesions were metastatic and the remaining 26 lesions were benign. For the depiction of adrenal gland metastasis, the sensitivity, specificity, and accuracy of PET were 74%, 73%, and 74%, respectively, whereas those of integrated PET/CT were 80%, 89%, and 84%, respectively (p values; 0.5, 0.125, and 0.031, respectively). CONCLUSION: The use of integrated PET/CT is more accurate than the use of PET alone for differentiating benign and metastatic adrenal gland lesions in lung cancer patients.     

Breast Sparganosis Incidentally Detected by FDG PET/CT

Sparganosis is a rare, parasitic infection that is caused by the plercercoid tapeworm larvae of the genus Spirometra. Sparganosis is transmitted by ingestion of larvae-containing water or intermediate hosts, such as raw amphibians, and usually presented with a subcutaneous nodule in the abdominal wall, extremities, and genital organs. Among the various involved organs, the breast is a seldom encountered site for sparganosis. However, breast sparganosis has clinical importance, since it is generally presented with an indolent palpable mass that mimics malignancy, even without evidence of inflammation. Herein, we report a case of breast sparganosis that was detected incidentally by FDG PET/CT during staging work ups in a patient with gall bladder cancer.     

18F-FDG Uptake of Human Testis on PET/CT: Correlation with Age,Sex Hormones,and Vasectomy

Purpose

The purpose of this study was to evaluate glucose metabolism of normal human testis on ¹⁸F-FDG PET/CT and to assess possible correlations among age, the serum levels of sex hormones, and vasectomy.

Methods

¹⁸F-FDG PET/CT was performed in 66 normal healthy men (50.8 ± 13.6 years, range 22–81), and mean standard uptake values (SUV) of ¹⁸F-FDG in testis and adductor muscle were measured. Testis-muscle SUV ratios (T/M ratios) were calculated. Serum levels of total testosterone, free testosterone, estradiol, and of sex-hormone binding globulin (SHBG) were measured. We searched for correlations between T/M ratios and age and the serum concentrations of sex hormones. ¹⁸F-FDG PET/CT was also performed in 32 vasectomized men (55.7 ± 7.8 years, range 38–71) and 52 nonvasectomized men (55.4 ± 11.6 years, range 37–72). Mean SUVs of testis and adductor muscle were measured, and T/M ratios were calculated.

Results

A significant age-related decline was found in T/M ratio (r = −0.509, p < 0.0001). Serum levels of total testosterone and free testosterone were also found to be positively correlated with T/M ratio (r = 0.427, p = 0.0003; r = 0.435, p = 0.0003, respectively). The mean SUV and T/M ratio of vasectomized men were significantly lower than those of nonvasectomized men (p < 0.0378 and p = 0.0001, respectively).

Conclusions

Glucose metabolism in the testis in an adult population was found to be correlated with age, serum sex hormone level, and vasectomy history. These results indicate that testicular ¹⁸F-FDG uptake may have attributed to testicular function and testicular histology. Our findings may have important implications for the interpretation of testicular ¹⁸F-FDG uptake in the normal adult population.     

The Prognostic Value of 18F-FDG PET/CT for Early Recurrence in Operable Breast Cancer: Comparison with TNM Stage

Purpose

We evaluated whether the maximum standardized uptake values (SUV_max) of primary tumor from the initial staging by ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) of patients with breast cancer could identify patients at risk for early recurrence within 2 years, particularly in comparison to the American Joint Committee on Cancer (AJCC) stage.

Methods

We reviewed the staging ¹⁸F-FDG PET/CT images of patients with primary breast cancer and their medical records. The SUV_max of the primary tumor was measured. The presence or absence of FDG uptake in the axillary lymph node (ALN) was also assessed. The patient’s pathologic primary tumor stage (pT), pathologic regional lymph node stage (pN), stage grouping, age, estrogen receptor (ER) and progesterone receptor (PR) status, and neoadjuvant chemotherapy history were evaluated with the FDG uptake parameters for recurrence within 2 years following the end of first-line therapy.

Results

Recurrence within 2 years was present in 9.1 % (n = 40) out of the 441 patients assessed. The FDG uptake in ALN, pT, pN, stage grouping and neoadjuvant chemotherapy history were prognostic for early recurrence, while primary tumor SUV_max, age, and ER or PR status were not significant on logistic regression. On multivariate analysis, only the stage grouping (odds ratio 2.79; 95 % CI 1.73, 4.48; p < 0.0001) and neoadjuvant chemotherapy history (odds ratio 2.70; 95 % CI 1.22, 5.98; p = 0.0141) could identify patients at increased risk for recurrence within 2 years.

Conclusions

Primary tumor FDG uptake measured by SUV_max, and visual assessment of FDG uptake in the ALN in the initial staging PET/CT of patients with breast cancer may not have additional prognostic value compared with the AJCC stage grouping for early recurrence.     

Nonfunctioning endocrine pancreatic tumor examined with 18F-FDG PET/CT

A 71-year-old woman with type 2 diabetes mellitus complained of generalized fatigue. A 36-mm tumor in the pancreatic tail was detected with ultrasonography. The tumor was found to have marked hypervascularity with contrast-enhanced computed tomography (CT) and magnetic resonance. Combined ¹⁸F-fluorodeoxyglucose positron emission tomography and CT (¹⁸F-FDG PET/CT) showed ¹⁸F-FDG by the tumor with a maximal standardized uptake value of 2.98 at 50 min and 3.29 at 100 min following injection of ¹⁸F-FDG. ¹⁸F-FDG PET/CT suggested no extrapancreatic spread of the tumor. The patient had no pancreatic hormone-associated symptoms. Distal pancreatectomy was performed, and a well-differentiated endocrine tumor was diagnosed. The resected specimen showed neither infiltration of adjacent structures nor metastasis to regional lymph nodes. The present case suggests that ¹⁸F-FDG PET/CT is a reliable modality for staging endocrine pancreatic tumors.     

Pulmonary Actinomycosis Imitating Lung Cancer on 18F-FDG PET/CT: A Case Report and Literature Review

Here we report a case of 41-year-old man with a soft tissue density mass at right upper lung and palpable abscesses at right upper backside and right wrist. ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography demonstrated a 7.8 × 5.0 cm mass with soft-tissue density in the upper lobe of the right lung with high metabolic activity. The infiltrative mass extended to adjacent chest wall soft tissue. Final diagnosis of pulmonary actinomycosis with multiple abscesses was made. The patient responded well to antibiotics treatment.     

Primary Pulmonary Low-Grade Angiosarcoma Characterized by Mismatch between 18F-FDG PET and Dynamic Contrast-Enhanced CT

We report a rare case of primary pulmonary low-grade angiosarcoma on dynamic contrast-enhanced CT and ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT imaging. A 38-year-old, asymptomatic woman was hospitalized because of an abnormality on chest radiography. A dynamic contrast-enhanced chest CT showed a 1.2 cm-sized irregular-margined nodule with strong and persistent enhancement in the right lower lobe. The lesion had low metabolic activity on an ¹⁸F-FDG PET/CT scan. The patient underwent a wedge resection for the lesion, and pathology revealed a primary pulmonary low-grade angiosarcoma.     

Imaging Findings and Literature Review of 18F-FDG PET/CT in Primary Systemic AL Amyloidosis

Purpose

Although several case reports and case series have described ¹⁸F-FDG PET/CT in amyloidosis, the value of ¹⁸F-FDG PET/CT for diagnosing amyloidosis has not been clarified. We investigated the imaging findings of ¹⁸F-FDG PET/CT in patients with primary systemic AL amyloidosis.

Methods

Subjects were 15 patients (M:F = 12:3; age, 61.5 ± 7.4 years) with histologically confirmed primary systemic AL amyloidosis who underwent pretreatment ¹⁸F-FDG PET/CT to rule out the possibility of malignancy or for initial workup of alleged cancer. For involved organs, visual and semiquantitative analyses were performed on ¹⁸F-FDG PET/CT images. In total, 22 organs (10 hearts, 5 kidneys, 2 stomachs, 2 colons, 1 ileum, 1 pancreas, and 1 liver) were histologically confirmed to have primary systemic AL amyloidosis.

Results

F-FDG uptake was significantly increased in 15 of the 22 organs (68.2 %; 10 hearts, 2 kidneys, 1 colon, 1 ileum, and 1 liver; SUVmax = 7.0 ± 3.2, range 2.1–14.1). However, in 11 of 15 PET-positive organs (78.6 %; 10 hearts and the ileum), it was difficult to differentiate pathological uptake from physiological uptake. Definitely abnormal ¹⁸F-FDG uptake was found in only 4 of the 22 organs (18.2 %; 2 kidneys, 1 colon, and the liver). ¹⁸F-FDG uptake was negative for pancreas and gastric lesions.

Conclusions

Although ¹⁸F-FDG PET/CT showed high uptake in two-thirds of the organs involving primary systemic AL amyloidosis, its sensitivity appeared to be low to make differentiation of pathological uptake from physiological uptake. However, due to the small number of cases, further study for the role of ¹⁸F-FDG PET/CT in amyloidosis will be warranted.     

Peliosis Hepatis Shows Isometabolism on 18F-FDG PET/CT: Two Case Reports

Peliosis hepatis (PH) is a rare benign disease that is characterized by multiple blood-filled cystic spaces in the hepatic parenchyma. It is also characterized by a range of radiologic findings that might mimic various diseases, including metastatic liver disease and hepatocellular carcinoma. The findings of PH on ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) are not well reported. We here report two cases of biopsy-proven PH. Both patients had been treated for cancer (advanced gastric carcinoma and rectal adenocarcinoma), and follow-up CT of both cases revealed hepatic lesions with the possibility of metastasis. Examination of ¹⁸F-FDG PET/CT images suggested that the lesions were isometabolic, having metabolism similar to that of adjacent hepatic parenchyma. The outcomes of hepatic core-needle biopsies were consistent with peliosis hepatis.     

多发性骨髓瘤的18F-FDGPET/CT诊断

目的:多发性骨髓瘤是一种浆细胞恶性增殖性疾病,大约有80％的患者存在骨骼侵犯.本文探讨多发性骨髓瘤的18F-fluorodexoxyglucose(18F-FDG)PET/CT表现特点,提高对多发性骨髓瘤的认识.方法:26例按2001年WHO诊断标准确诊为多发性骨髓瘤的患者,均在治疗前行18F-FDG PET/CT显像.所有患者均依赖骨髓穿刺或活检取得明确病理学诊断.结果:26名患者均出现不同程度的骨质疏松.25例患者出现多发性骨质破坏,占总数的96.2％;其中11例患者出现颅骨破坏,占42.3％;25例出现脊柱骨质破坏,占96.2％;15例出现胸骨骨质破坏,占57.7％;21例出现肋骨骨质破坏,占80.8％;21例出现骨盆骨质破坏,占80.8％.部分骨破坏病灶呈18F-FDG高代谢灶.结论:多发性骨髓瘤的18F-FDG PET/CT表现具有一定特征,结合临床、影像、实验室和病理学检查能提高本病的诊断率.     

18F-FDG PET/CT in Primary AL Hepatic Amyloidosis Associated with Multiple Myeloma

We report here on a rare case of primary AL hepatic amyloidosis associated with multiple myeloma in a 64-year-old woman. The patient was referred for evaluating her progressive jaundice and right upper quadrant pain. ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) showed diffusely and markedly increased ¹⁸F-FDG uptake in the liver. Although there have been several case studies showing positive ¹⁸F-FDG uptake in pulmonary amyloidosis, to the best of our knowledge, the ¹⁸F-FDG PET/CT findings of hepatic amyloidosis or primary hepatic amyloidosis associated with multiple myeloma have not been reported previously.     

Prognostic Significance of Volume-based Metabolic Parameters by 18F-FDG PET/CT in Gallbladder Carcinoma

Purpose

We investigated the prognostic values of volume-based metabolic parameters by ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) in gallbladder carcinoma patients and compared them with other prognostic parameters.

Materials and Methods

We enrolled 44 patients, who were initially diagnosed with gallbladder carcinoma and undergoing ¹⁸F-FDG PET/CT. Various metabolic volume-based PET parameters of primary tumors, including maximum and average standardized uptake values (SUV_max, SUV_avg), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), were measured in gallbladder carcinoma patients using mediastinal blood pool activity as a threshold SUV for determining the tumor boundaries. Overall survival analysis was performed using the Kaplan-Meier method with PET parameters and other clinical variables. For determining independent prognostic factors, Cox proportional hazards regression analysis was performed.

Results

Of the 44 enrolled patients, cancer- or treatment-related death occurred in 30 (68.2 %). The mean clinical follow-up period was 22.2 ± 10.4 m (range, 0.6-35.9 m). Univariate analysis demonstrated that clinical or pathologic TNM stage (P < 0.001), treatment modality (P < 0.001), MTV (cutoff = 135 cm³, P = 0.001), and TLG (cutoff = 7,090, P < 0.05) were significant prognostic factors. In multivariate analysis, both clinical or pathologic TNM stage [hazard ratio (HR) = 2.019 (I vs II), 21.287 (I vs III), and 24.354 (I vs IV); P = 0.001) and TLG (HR = 2.930; P < 0.05) were independent prognostic factors for predicting overall survival.

Conclusions

In gallbladder cancer, TLG of the primary tumor, a volume-based metabolic parameter, is a significant independent prognostic factor for overall survival in conjunction with the clinical or pathological TNM stage.     

18F-FDOPA与18F-FDG PET/CT诊断脑肿瘤的系统评价

目的 系统评价18F-FDOPA与18F-FDG PET/CT显像在脑肿瘤诊断中的临床价值.方法 采用Meta分析与直接比较方法.使用计算机检索中国期刊全文数据库、中文科技期刊数据库、万方数据库、中国生物医学文献数据库、PubMed、Embase、The Cochrane Library,从建库至2016年10月,搜索直接比较18F-FDOPA与18F-FDG PET/CT诊断脑肿瘤的诊断性试验.用Meta-Disc 1.4软件进行分析,计算两种不同显像剂的合并敏感度(sensitivity,SEN)、合并特异度(specificity,SPE)、合并阳性似然比(positive likelihood ratio,+LR)、合并阴性似然比(negative likelihood ratio,-LR)、诊断优势比(diagnostic odds ratio,DOR),并绘制综合受试者工作特征曲线计算曲线下面积(area under curve,AUC)与Q*值.结果 最终共纳入4篇文章,Meta 分析结果显示,18F-FDOPA PET/CT对脑肿瘤诊断的合并SEN为0.97(95％ CI =0.90 ～ 1.00),SPE为0.67(95％ CI =0.45 ～0.84),+LR为2.31 (95％ CI=1.40 ～3.81),-LR为0.07 (95％ CI =0.02～ 0.24),DOR为39.72(95％ CI=8.94～176.48),AUC为0.9725,Q*为0.9239.18F-FDG PET/CT对脑肿瘤诊断的合并SEN为0.51(95％CI=0.39～0.63),SPE为0.75(95％ CI=0.53 ～0.90,+LR为l.59(95％ CI=0.70 ～ 3.61),-LR为0.63(95％ CI =0.47 ～0.86),DOR为2.55(95％ CI =0.82 ～7.92),AUC为0.5848,Q*为0.5638.结论 18F-FDOPA PET/CT显像诊断脑肿瘤的敏感性比18F-FDG高,对脑肿瘤具有良好的诊断价值,可作为脑肿瘤诊断的方法之一.     

Evaluation of gross tumor size using CT, 18F-FDG PET, integrated 18F-FDG PET/CT and pathological analysis in non-small cell lung cancer

Purpose

The correlation of gross tumor sizes between combined ¹⁸F-FDG PET/CT images and macroscopic surgical samples has not yet been studied in detail. In the present study, we compared CT, ¹⁸F-FDG PET and combined ¹⁸F-FDG PET/CT for the delineation of gross tumor volume (GTV) and validated the results through examination of the macroscopic surgical specimen.

Methods

Fifty-two operable non-small cell lung cancer (NSCLC) patients had integrated ¹⁸F-FDG PET/CT scans preoperatively and pathological examination post-operation. Four separate maximal tumor sizes at X (lateral direction), Y (ventro-dorsal direction) and Z (cranio-caudal direction) axis were measured on ¹⁸F-FDG PET, CT, combined ¹⁸F-FDG PET/CT and surgical specimen, respectively. Linear regression was calculated for each of the three imaging measurements versus pathological measurement.

Results

No significant differences were observed among the tumor sizes measured by three images and pathological method. Compared with pathological measurement, CT size at X, Y, Z axis was larger, whereas combined ¹⁸F-FDG PET/CT and ¹⁸F-FDG PET size were smaller. Combined ¹⁸F-FDG PET/CT size was more similar to the pathological size than that of ¹⁸F-FDG PET or CT. Results of linear regressions showed that integrated ¹⁸F-FDG PET/CT was the most accurate modality in measuring the size of cancer.

Conclusions

¹⁸F-FDG PET/CT correlates more faithfully with pathological findings than ¹⁸F-FDG PET or CT. Integrated ¹⁸F-FDG PET/CT is an effective tool to define the target of GTV in radiotherapy.     

Prospective assessment of 18F-FDG PET/CT in detection of recurrent ovarian cancer

Objective

To assess the use of positron emission tomography (PET)/computed tomography (CT) in patients with suspected ovarian cancer recurrence and describe the distribution of metastasis.

Patients and methods

This study included (39) patients suspected to have recurrent ovarian malignancy. This suspicion was either clinically, radiologically or due to raised CA-125 levels. All patients underwent 18F-FDG PET/CT, surgery was performed within 8 weeks of imaging studies. Surgical and/or histopathological examinations were available in 31 patients, and clinical, radiological and CA 125 serum level follow up in 8 patients.

Results

The overall lesion-based sensitivity, specificity, and accuracy of PET/CT for revealing recurrent ovarian carcinoma were 90%, 98% and 97%, respectively. The patient – based sensitivity, specificity, and accuracy of PET/CT were 97%, 75% and 95%, respectively.

Conclusion

18F-FDG PET/CT is a useful tool for evaluating the recurrence of ovarian cancer after first-line therapy in patients with a high risk of relapse, equivocal radiologic findings, increased or normal levels of serum CA-125. It can more accurately diagnose and localize recurrence, hence decreasing the rate of second look surgery and changing treatment plan.     

Diagnostic Performance of 68Ga-DOTATATE PET/CT, 18F-FDG PET/CT and 131I-MIBG Scintigraphy in Mapping Metastatic Pheochromocytoma and Paraganglioma

Purpose

To evaluate the diagnostic performance of ⁶⁸Ga-DOTATATE ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT), ¹⁸F-FDG PET/CT and ¹³¹I-MIBG scintigraphy in the mapping of metastatic pheochromocytoma and paraganglioma.

Materials and Methods

Seventeen patients (male = 8, female = 9; age range, 13–68 years) with clinically proven or suspicious metastatic pheochromocytoma or paraganglioma were included in this prospective study. Twelve patients underwent all three modalities, whereas five patients underwent ⁶⁸Ga-DOTATATE and ¹³¹I-MIBG without ¹⁸F-FDG. A composite reference standard derived from anatomical and functional imaging findings, along with histopathological information, was used to validate the findings. Results were analysed on a per-patient and on per-lesion basis. Sensitivity and accuracy were assessed using McNemar’s test.

Results

On a per-patient basis, 14/17 patients were detected in ⁶⁸Ga-DOTATATE, 7/17 patients in ¹³¹I-MIBG, and 10/12 patients in ¹⁸F-FDG. The sensitivity and accuracy of ⁶⁸Ga-DOTATATE, ¹³¹I-MIBG and ¹⁸F-FDG were (93.3 %, 94.1 %), (46.7 %, 52.9 %) and (90.9 %, 91.7 %) respectively. On a per-lesion basis, an overall of 472 positive lesions were detected; of which 432/472 were identified by ⁶⁸Ga-DOTATATE, 74/472 by ¹³¹I-MIBG, and 154/300 (patient, n = 12) by ¹⁸F-FDG. The sensitivity and accuracy of ⁶⁸Ga-DOTATATE, ¹³¹I-MIBG and ¹⁸F-FDG were (91.5 %, 92.6 % p < 0.0001), (15.7 %, 26.0 % p < 0.0001) and (51.3 %, 57.8 % p < 0.0001) respectively. Discordant lesions were demonstrated on ⁶⁸Ga-DOTATATE, ¹³¹I-MIBG and ¹⁸F-FDG.

Conclusions

Ga-DOTATATE PET/CT shows high diagnostic accuracy than ¹³¹I-MIBG scintigraphy and ¹⁸F-FDG PET/ CT in mapping metastatic pheochromocytoma and paraganglioma.     

Impact of Nonosseous Findings on 18F-NaF PET/CT in a Patient with Ductal Breast Carcinoma

¹⁸F-NaF was used as a bone-seeking PET tracer for skeletal imaging until the introduction of the widely available ^99mTc-labeled bone agents. However, there is renewed clinical interest in ¹⁸F-NaF since prior technical and logistic limitations to its routine use are no longer present, and, as a consequence, it is likely that uptake unrelated to bone and non-osseous findings will be encountered more frequently. As a result of tumoral necrosis, soft tissue metastases may demonstrate ¹⁸F-NaF avidity due to dystrophic calcification. On the other hand, all non-osseous findings, whether ¹⁸F-NaF avid or not, may provide important diagnostic information that may alter the course of the disease, including treatment options. Herein we present a patient with ductal carcinoma of the breast in whom findings unrelated to the skeletal system in ¹⁸F-NaF PET/CT altered the treatment strategy.     

Prognostic Value of Volume-Based Metabolic Parameters Measured by 18F-FDG PET/CT of Pancreatic Neuroendocrine Tumors

Purpose

To date, the prognostic value of ¹⁸F-FDG PET/CT for patients with pancreatic neuroendocrine tumors (PNETs) has not been well characterized. We investigated the prognostic value of volumetric parameters using ¹⁸F-FDG PET/CT in this patient population.

Methods

We retrospectively reviewed 20 cases of pathologically proven PNET in patients who had undergone pre-therapeutic ¹⁸F-FDG PET/CT. PET parameters including maximum and average standardized uptake values (SUV_max, SUV_ave), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary tumor were measured using a threshold SUV to determine the boundaries of the tumors. Univariate and multivariate survival analyses were performed with adjustments for PET parameters and other clinical values.

Results

The median clinical follow-up was 22.3 (range, 1.2–95.4) months. Cancer-related death occurred in 5 of 20 patients (25 %). Patients had clinical or pathological stages of I in seven patients, II in six patients, III in three patient, and IV in four patients. According to the WHO histological classification of subtypes, 3 patients exhibited well-differentiated PNETs, 13 patients had well-differentiated endocrine carcinomas, and 4 had poorly differentiatedendocrine carcinomas. Univariate analysis showed that tumor size (p = 0.028), AJCC stage (p = 0.009), T stage (p = 0.028), M stage (p = 0.029), treatment modality (p = 0.045), MTV (p = 0.003) and TLG (p = 0.027) were significant predictors of overall survival. On multivariate analysis, MTV (HR = 10.859, p = 0.031) was a significant independent predictor of overall survival along with the AJCC stage (HR = 11.556, p = 0.027).

Conclusion

In patients with PNETs, the MTV of the primary tumor as measured by ¹⁸F-FDG PET/CT along with the AJCC stage may be a significant independent prognostic factor for overall survival.