Usefulness of 18F-fluoride PET/CT in Breast Cancer Patients with Osteosclerotic Bone Metastases

Purpose

Bone metastasis is an important factor for the treatment and prognosis of breast cancer patients. Whole-body bone scintigraphy (WBBS) can evaluate skeletal metastases, and ¹⁸F-FDG PET/CT seems to exhibit high specificity and accuracy in detecting bone metastases. However, there is a limitation of ¹⁸F-FDG PET in assessing sclerotic bone metastases because some lesions may be undetectable. Recent studies showed that ¹⁸F-fluoride PET/CT is more sensitive than WBBS in detecting bone metastases. This study aims to evaluate the usefulness of ¹⁸F-fluoride PET/CT by comparing it with WBBS and ¹⁸F-FDG PET/CT in breast cancer patients with osteosclerotic skeletal metastases.

Materials and Methods

Nine breast cancer patients with suspected bone metastases (9 females; mean age ± SD, 55.6 ± 10.0 years) underwent ^99mTc-MDP WBBS, ¹⁸F-FDG PET/CT and ¹⁸F-fluoride PET/CT. Lesion-based analysis of five regions of the skeletons (skull, vertebral column, thoracic cage, pelvic bones and long bones of extremities) and patient-based analysis were performed.

Results

¹⁸F-fluoride PET/CT, ¹⁸F-FDG PET/CT and WBBS detected 49, 20 and 25 true metastases, respectively. Sensitivity, specificity, positive predictive value and negative predictive value of ¹⁸F-fluoride PET/CT were 94.2 %, 46.3 %, 57.7 % and 91.2 %, respectively. Most true metastatic lesions on ¹⁸F-fluoride PET/CT had osteosclerotic change (45/49, 91.8 %), and only four lesions showed osteolytic change. Most lesions on ¹⁸F-FDG PET/CT also demonstrated osteosclerotic change (17/20, 85.0 %) with three osteolytic lesions. All true metastatic lesions detected on WBBS and ¹⁸F-FDG PET/CT were identified on ¹⁸F-fluoride PET/CT.

Conclusion

¹⁸F-fluoride PET/CT is superior to WBBS or ¹⁸F-FDG PET/CT in detecting osteosclerotic metastatic lesions. ¹⁸F-fluoride PET/CT might be useful in evaluating osteosclerotic metastases in breast cancer patients.     

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.     

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.     

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.     

Late Port Site Metastasis from Occult Gall Bladder Carcinoma After Laparoscopic Cholecystectomy for Cholelithiasis: The Role of 18F-FDG PET/CT

Late port site metastasis of gall bladder carcinoma (GBC) after laparoscopic cholecystectomy is a rare finding. Rarer still is such a presentation where the GBC remained occult at histopathology. ¹⁸F-flurodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) can play an important role in this setting by supporting the diagnosis of port site metastasis, by demonstrating additional sites of metastasis, if any, and by ruling out any other primary site. We here present two such patients with late port site metastasis of occult GBC after laparoscopic cholecystectomy for cholelithiasis and discuss the role of ¹⁸F-FDG PET/CT in this setting.     

Comparison of diagnostic ability between 99mTc-MDP bone scan and 18F-FDG PET/CT for bone metastasis in patients with small cell lung cancer

Objective

The aim of this study was to compare the diagnostic ability of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) with that of ^99mTc-methylene diphosphonate (^99mTc-MDP) bone scan for bone metastasis in staging patients with small cell lung cancer (SCLC).

Methods

Ninety-five patients with SCLC who underwent both ¹⁸F-FDG PET/CT and ^99mTc-MDP bone scan for initial staging work-up were retrospectively enrolled. All ¹⁸F-FDG PET/CT and bone scan images were visually assessed. Bone metastasis was confirmed by histopathological results and all available clinical information.

Results

Of 95 patients with SCLC, metastatic bone lesions were found in 30 patients, and 84 metastatic lesions were evaluated on a lesion-basis analysis. The sensitivity of ¹⁸F-FDG PET/CT was 100?% on a per-patient basis and 87?% on a per-lesion basis, and there was no false-positive lesion on PET/CT images. In contrast, the sensitivity of the bone scan was 37?% on a per-patient basis and 29?% on a per-lesion basis. The bone scan showed 11 false-positive lesions. The bone scan detected two metastatic lesions that were not detected by PET/CT, which were outside the region scanned by PET/CT. On follow-up bone scan, 21 lesions that were not detected by the initial bone scan but were detected by PET/CT were newly detected.

Conclusions

In patients with SCLC, ¹⁸F-FDG PET/CT showed higher detection rate of bone metastasis than ^99mTc-MDP bone scan. Thus, ¹⁸F-FDG PET/CT can replace bone scan in staging patients with SCLC.     

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.     

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.     

Opportunities for 2-[18F] Fluoro-2-Deoxy-D-Glucose PET/CT in Cervical-Vaginal Neuroendocrine Carcinoma: Case Series and Literature Review

Objective

Neuroendocrine cervical carcinoma is a rare subtype of cervical cancer. These tumors exhibit an aggressive behavior with early regional lymph node and distant metastases. The purpose of our study was to describe five cases of neuroendocrine cervical-vaginal carcinoma and to discuss the potential of the 2-[¹⁸F] fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) scan for the detection of this rare malignancy.

Materials and Methods

Five cases of cervical-vaginal neuroendocrine tumor were retrospectively collected, during a two year (from September 2009 to August 2011) period in our hospital. The clinical staging distributions were International Federation of Gynecology and Obstetrics (FIGO) stage IB2 (1 of 5), stage IIA (3 of 5) and stage IVA (1 of 5).

Results

Two cases (cases 1 and 4) were restaged after ¹⁸F-FDG PET/CT scan in the initial staging process. Post-treatment ¹⁸F-FDG PET/CT scans, in three patients, revealed positive findings for tumor recurrence or lymph node metastases. Two patients (cases 2 and 3) died of tumor within two years.

Conclusion

¹⁸F-FDG PET/CT scan is a useful tool in cervical-vaginal neuroendocrine tumor. In its initial staging, the ¹⁸F-FDG PET/CT scan may help assess the possible nodal involvement or early hematogeneous spreading. We can also use the ¹⁸F-FDG PET/CT to detect local recurrence and to evaluate the treatment response after clinical manipulation.     

Comparisons between glucose analogue 2-deoxy-2-(18F)fluoro-D-glucose and 18F-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).     

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.     

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.     

Radiography,Bone Scan,and F-18 FDG PET/CT Imaging Findings in a Patient with Paget’s Disease

Background

A 52-year-old female patient sought evaluation at our hospital for an incidental abnormal finding on an abdominal radiograph.

Methods

The initial radiograph showed irregular sclerotic changes involving the right pelvic bone. At the same time, bone scintigraphy showed intense hot uptake in the right iliac and pubic bones. CT images showed characteristic thickening of the pelvic brim, suggesting the mixed phase of Paget’s disease.

Results

The level of alkaline phosphatase (ALP) was 266 IU/l. ¹⁸F-FDG PET/CT images also showed diffusely increased ¹⁸F-FDG uptake in the right pelvic bone. However, the findings of ¹⁸F-FDG PET/CT were less notable than those of bone scintigraphy.

Conclusion

We report the imaging findings of a patient with Paget’s disease evaluated by radiography, bone scintigraphy, and ¹⁸F-FDG PET/CT.     

Using 18F-FDG PET/CT to Detect an Occult Mesenchymal Tumor Causing Oncogenic Osteomalacia

Oncogenic osteomalacia is a rare paraneoplastic syndrome characterized by renal phosphate excretion, hypophosphatemia, and osteomalacia. This syndrome is often caused by tumors of mesenchymal origin. Patients with oncogenic osteomalacia have abnormal bone mineralization, resulting in a high frequency of fractures. Tumor resection is the treatment of choice, as it will often correct the metabolic imbalance. Although oncogenic osteomalacia is a potentially curable disease, diagnosis is difficult and often delayed because of the small size and sporadic location of the tumor. Bone scintigraphy and radiography best characterize osteomalacia; magnetic resonance imaging findings are nonspecific. Here, we report a case of oncogenic osteomalacia secondary to a phosphaturic mesenchymal tumor that was successfully detected by ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT). This case illustrates the advantages of ¹⁸F-FDG PET/CT in detecting the occult mesenchymal tumor that causes oncogenic osteomalacia.     

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.     

A first described chest wall metastasis from colon cancer demonstrated with (18)F-FDG PET/CT

It is well known that, haematogenous colon cancer metastases are most commonly found in the liver, less likely in the lungs through the paravertebral venous system and rarely in other organs. Sporadic clinical cases of colon cancer metastases to the abdominal wall, the thyroid or the adrenal glands have been reported. Here, we present an uncommon case of chest wall metastasis from colon cancer demonstrated with 2-fluoro [fluorine-18]-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT). A 52 years old female patient was examined after she felt a swelling mass above her left breast. Tumor makers, such as serum cancer embryonic antigen (CEA) 146.22kU/L (normal range:0.00~37.0kU/L) and CA19-9 (258.16μg/L (normal range:0.00~10.0μg/L) and neuron-specific enolase (NSE) 78.2 (normal range: 0.00~17.00) were abnormally high. Chest CT revealed the soft tissue density mass on the left anterior chest wall with invasion of left 4th rib, and CT-guided biopsy showed a poorly differentiated adenocarcinoma of unkown origin. The patient was then referred for the (18)F-FDG-PET scan which was performed one hour after the intravenous injection of 370MBq of (18)F-FDG (Discovery Camera, VCT, GE, USA) and showed in addition to the chest mass, abnormal (18)F-FDG accumulation in both lungs, left supraclavicular and peritoneal lymph nodes. Furthermore, high (18)F-FDG uptake was detected in the sigmoid. Pathology findings from colonoscopy confirmed that this was a sigmoid colon adenocarcinoma. So far, chest wall metastasis from colon cancer as an initial finding has not been reported. Usually, an initial chest wall mass is hardly suspected to be a colon cancer metastasis. Abnormal serum tumor markers such as CEA and CA19-9 supported the diagnosis of a gastrointestinal adenocarcinoma. In our case, we found high serum NSE and normal findings of bowel wall on the CT scan, thus without the positive (18)F-FDG findings, one would probably consider as first diagnosis: chest wall metastasis from lung cancer, or a neuroendocrine tumor. The unusual finding in this case was that on the CT images there was no obvious local density of the intestine, no bowel wall thickening, or suspicious nodular lesions. Segmental (18)F-FDG accumulation seen in the sigmoid colon had early maximum standardized uptake value (SUV(max)) 7.3 and in 1h delayed estimation, 8.1. Colonoscopy showed that the (18)F-FDG-avid area at the colon was circular and thickened. "Hot" lesions found in both lungs, the supraclavicular and retroperitoneal lymph nodes by (18)F-FDG PET/CT scan were considered to be most probably metastases from colon adenocarcinoma. In conclusion, PET as a rather simple procedure and less dependent on bowel preparation diagnosed the primary colon cancer, its metastases and specifically a first described chest wall metastasis, while CT alone did not show the primary tumor.     

Usefulness of 18F-FDG PET/CT for the Evaluation of Bone Marrow Involvement in Patients with High-Grade Non-Hodgkin’s Lymphoma

Purpose

To assess the usefulness of ¹⁸F-fluorodeoxyglucose PET/CT in the detection of bone marrow (BM) involvement of high-grade non-Hodgkin’s lymphoma (NHL).

Methods

One hundred twenty patients with newly diagnosed diffuse large B-cell lymphoma or peripheral T-cell lymphoma between January 2007 and June 2011, who received BM trephine biopsy and ¹⁸F-FDG PET/CT before chemotherapy, were included in this retrospective study. We reviewed their ¹⁸F-FDG PET/CT images and bone marrow biopsy (BMB) results. After reviewing the images, we reviewed the medical records and radiological findings of interesting patients.

Results

There were 23 ¹⁸F-FDG PET/CT scans in which the marrow was considered to be abnormal (either positive or equivocal), and 97 ¹⁸F-FDG PET/CT scans were regarded as having negative FDG uptake. Of 120 patients, 100 (83.3 %) had a concordant result of BM interpretation between ¹⁸F-FDG PET/CT and BMB, and the remaining 20 patients had discordant results. Among 23 patients with either positive or equivocal ¹⁸F-FDG PET/CT scans, 1 of 12 patients with ‘positive’ ¹⁸F-FDG PET/CT had a lymphomatous involvement on BMB. In contrast, 10 of 11 patients with ‘equivocal’ BM hypermetabolism were reported as having positive involvement by BMB. Patients with abnormal ¹⁸F-FDG PET/CT had significantly higher mSUV_highest than those with normal FDG-PET/CT.

Conclusions

¹⁸F-FDG PET/CT and BMB are complementary techniques in assessing the presence of BM involvement in patients with high-grade NHL. The increasing availability of ¹⁸F-FDG PET/CT will raise the need for additional biopsy for FDG-avid lesions, especially in patients with negative standard BMBs. ¹⁸F-FDG PET/CT can be useful as a decision-making tool for determining whether to perform a standard BMB or targeted biopsy to the FDG-avid lesion as an initial staging procedure. A direct bone biopsy for FDGpositive bone lesions should be included in staging guidelines in future. In ¹⁸F-FDG PET/CT-negative cases, BMB is still a powerful procedure, but BMB alone is insufficient for full evaluation of BM.     

<Superscript>18</Superscript>F-fluorodeoxyglucose positron emission tomography in uterine carcinosarcoma

Purpose Uterine carcinosarcomas clinically confined to the uterus usually harbor occult metastases. We conducted a pilot study to evaluate the value of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in uterine carcinosarcoma. Methods Patients with histologically confirmed uterine carcinosarcoma were enrolled. Abdominal and pelvic magnetic resonance imaging (MRI)/whole-body computed tomography (CT) scan, and whole-body ¹⁸F-FDG PET or PET/CT were undertaken for primary staging, evaluating response, and restaging/post-therapy surveillance. The clinical impact of ¹⁸F-FDG PET was determined on a scan basis. Results A total of 19 patients were recruited and 31 ¹⁸F-FDG PET scans (including 8 scans performed on a PET/CT scanner) were performed. Positive impacts of scans were found in 36.8% (7/19) for primary staging, 66.7% (2/3) for monitoring response, and 11.1% (1/9) for restaging/post-therapy surveillance. PET excluded falsely inoperable disease defined by MRI in two patients. Aggressive treatment applying to three patients with PET-defined resectable stage IVB disease seemed futile. Two patients died of disease shortly after salvage therapy restaged by PET. With PET monitoring, one stage IVB patient treated by targeted therapy only was alive with good performance. Using PET did not lead to improvement of overall survival of this series compared with the historical control (n = 35) (P = 0.779). Conclusions The preliminary results suggest that ¹⁸F-FDG PET is beneficial in excluding falsely inoperable disease for curative therapy and in making a decision on palliation for better quality of life instead of aggressive treatment under the guidance of PET. PET seems to have limited value in post-therapy surveillance or restaging after failure.     

A case of renal pelvic tumor visualized by<Superscript>18</Superscript>F-FDG-PET imaging

18F fluorodeoxyglucose positron emission tomography (18F-FDG PET) imaging is a useful modality in detecting various tumors, including renal cell carcinoma. We evaluated a patient with renal pelvic tumor (transitional cell carcinoma) with multiple metastases using 18F-FDG PET imaging and detected abnormal increased uptake of a right renal pelvic tumor extending to the renal cortex with liver metastasis and paraaortic lymph node metastases. These results suggest that 18F-FDG PET imaging may be useful in detecting primary and metastatic lesions of renal pelvic tumor (transitional cell carcinoma).