Role of 18F-FDG PET/CT, 123I-MIBG SPECT,and CT in Restaging Patients Affected by Malignant Pheochromocytoma

Purpose

Pheochromocytoma (PH) is a rare catecholamine-secreting tumor that arises from chromaffin tissue within the adrenal medulla and extra-adrenal sites; commonly it is sporadic, and malignant PH accounts for about 10% of all cases. Several imaging modalities have been used for the diagnosis and staging of this tumor: functional imaging using radio-labelled metaiodobenzylguanidine and, more recently, ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET/CT), which offers substantial sensitivity and specificity to correctly detect metastatic PH and helps to identify patients suitable for treatment with radiopharmaceuticals. The aim of our study was to compare CT, ¹⁸F-FDG PET/CT, and ¹²³I-metaiodobenzylguanidine single photon emission tomography (¹²³I-MIBG SPECT) as feasible methods to restage patients diagnosed histologically with PH.

Methods

We retrospectively evaluated 38 patients (27 females and 11 males; mean age: 44 ± 15 years) with malignant PH documented histologically after surgical intervention. These patients underwent CT, ¹⁸F-FDG PET/CT, and ¹²³I-MIBG SPECT.

Results

¹⁸F-FDG PET/CT showed positive results for neoplastic tissue in 33/38 patients (86.8%) and negative in 5/38 (13.2%), in concordance with CT alone. ¹²³I-MIBG SPECT was positive in 30/38 patients (78,9%) and negative in 8/38 (21.1%). No differences in lesion numbers were found between ¹⁸F-FDG PET/CT and CT, whereas a difference could be demonstrated between ¹⁸F-FDG PET/CT and ¹²³I-MIBG SPECT.

Conclusion

¹⁸F-FDG PET/CT could more accurately restage patients with PH than CT and ¹²³I-MIBG SPECT, also in the absence of a staging study.     

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.     

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.     

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.     

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.     

Multifocal Colonic Lesions Detected by 18F-FDG PET/CT: Correlation with Histopathology and Gross Specimen

A 73-year-old man underwent ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) for the staging of colon cancer. The ¹⁸F-FDG PET/CT revealed three colonic lesions. The histopathologic examination of the postoperative gross specimen revealed a tubular adenoma, a tubulovillous adenoma and an adenocarinoma. The maximal standardized uptake value (SUVmax) of a tubulovillous adenoma was much higher than that of adenocarcinoma. This patient could be considered as a representative case highlighting that SUVmax is not a reliable indicator for discriminating colon cancer from colonic adenomas.     

Comparison between 18F-FDG PET/CT and EMG Mapping for Identifying Dystonic Superficial Muscles in Primary Cervical Dystonia: Preliminary Results

Purpose

This study was conducted to compare ¹⁸F-FDG PET/CT and electromyography (EMG) mapping in patients with primary cervical dystonia (PCD) to find dystonic superficial cervical muscles.

Methods

Ten consecutive patients with PCD (M:F = 5:5, age 44 ± 13 years) whose dystonic posture was not relieved with conventional muscle relaxant therapy were included. Target cervical muscles for the comparison between ¹⁸F-FDG PET/CT and EMG mapping were four representative superficial bilateral cervical muscles: splenius capitis muscle, sternocleidomstoid muscle, upper trapezius muscle, and leavator scapulae muscle. The diagnostic efficacy was compared between ¹⁸F-FDG PET/CT and EMG mapping using physical exam and measurement of rotation angle as the gold standard.

Results

Among 80 muscles evaluated, there were 21 (26%) dystonic superficial cervical muscles assessed with physical exam and motion analysis. The sensitivity, specificity, and accuracy for localizing dystonic muscles were 76, 92, and 88% for ¹⁸F-FDG PET/CT, and 95, 66, and 74% for EMG mapping, respectively. The sensitivity of EMG mapping was significantly higher than that of ¹⁸F-FDG PET/CT. In contrast, ¹⁸F-FDG PET/CT was significantly superior to EMG mapping for specificity and accuracy.

Conclusions

¹⁸F-FDG PET/CT is more specific and accurate than EMG mapping for finding superficial dystonic cervical muscles. The high sensitivity of EMG mapping suggests that ¹⁸F-FDG PET/CT and EMG mapping are complementary for finding dystonic superficial cervical muscles.     

Small Cell Carcinoma of the Gallbladder: 18F-FDG PET/CT Imaging Features—A Case Report

The diagnostic role of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) for gallbladder small cell carcinoma has not been reported. A knowledge of the imaging characteristic features of this malignancy can be useful. Here we report a rare case of a patient who had various diagnostic imaging modalities, including ¹⁸F-FDG PET/CT.     

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 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.     

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.     

Usefulness of <Superscript>18</Superscript>F-FDG PET/CT to Detect Metastatic Mucinous Adenocarcinoma Within an Inguinal Hernia

Metastatic mucinous adenocarcinoma in an inguinal hernia is a rare disease and the image findings of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) are little known. Here, we introduce a 57-year-old man with metastatic mucinous adenocarcinoma in an inguinal hernia. On initial ¹⁸F-FDG PET/CT, hypermetabolism was observed in mucinous adenocarcinoma of the cecum, and adenocarcinomas of the transverse and ascending colon, respectively. Follow-up ¹⁸F-FDG PET/CT revealed newly developed multiple hypermetabolism in peritoneal seeding masses and nodules in the pelvic cavity and scrotum. Peritoneal carcinomatosis in the right pelvic side wall was extended to the incarcerated peritoneum and mesentery in the right inguinoscrotal hernia.¹⁸F-FDG PET/CT was useful to reveal unexpected peritoneal seeding within the inguinal hernia. Also, this case demonstrated that metastatic mucinous adenocarcinomas had variably intense FDG uptake.     

Metastatic urinary bladder paraganglioma on Ga-68 DOTATATE PET/CT

Paragangliomas are extra-adrenal catecholamine-secreting neuroendocrine tumors that can present with adrenergic signs and symptoms. The urinary bladder is a rare location for a paraganglioma, and these tumors must be distinguished from other more common bladder neoplasms. In this case report, we discuss a 59 year-old woman who initially presented with tachycardia, palpitations, chest tightness, shortness of breath, and weight loss. Laboratory evaluation showed significantly elevated catecholamines in the plasma and urine. A CT (Computed Tomography) scan of the abdomen and pelvis revealed an enhancing mass arising from the urinary bladder and an enlarged right pelvic lymph node. A follow up Ga-68 DOTATATE PET/CT (Positron Emission Tomography and/or Computed Tomography) showed increased uptake in the primary bladder mass, right pelvic lymph node, numerous skeletal lesions, and pulmonary nodules, consistent with metastatic paraganglioma of the urinary bladder. This case report demonstrates the radiological findings of metastatic urinary bladder paraganglioma and highlights the importance of skull base to mid-thigh PET/CT using Ga-68 DOTATATE. It is crucial for the radiologist to be familiar with the characteristics of urinary bladder paragangliomas and identify these tumors on imaging to allow prompt initiation of surgical resection and/or systemic therapy.     

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.     

18F-FDG PET/CT在鼻咽癌中的诊断价值

目的 探讨18F-FDG PET/CT在鼻咽癌中的诊断价值.方法 回顾性分析我院2007年3月～2010年3月以鼻咽部肿块就诊的36例患者资料,所有患者均行鼻咽部18F-FDG PET/CT检查及鼻内镜下取材病检确诊.结果 24例病检后确诊为鼻咽癌患者,18F-FDG PET/CT检查均为局限性高代谢灶;12例病检后确诊为鼻咽部炎性肿块患者中,8例18F-FDG PET/CT检查均为鼻咽部局限性低代谢灶,考虑炎症,有4例18F-FDG PET/CT检查为鼻咽部局限性高代谢灶,误诊为鼻咽癌.结论 18F-FDG PET/CT检查是诊断鼻咽癌的较好方法,结合患者临床症状,可以为鼻咽部肿块的良恶性鉴别提供可靠依据.     

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.     

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.