11C-choline positron emission tomography/computerized tomography for tumor localization of primary prostate cancer in comparison with 12-core biopsy

PURPOSE: (11)C-choline positron emission tomography is an innovative imaging technique for prostate cancer. We assessed the sensitivity of positron emission tomography used together with computerized tomography for intraprostatic localization of primary prostate cancer on a nodule-by-nodule basis, and compared its performance with 12-core transrectal biopsy. MATERIALS AND METHODS: In 43 patients with known prostate cancer who had received positron emission tomography/computerized tomography before initial biopsy, we assessed sensitivity of positron emission tomography/computerized tomography for localization of nodules 5 mm or greater (those theoretically large enough for visualization) using radical prostatectomy histopathology as the reference standard. Comparison with transrectal ultrasound guided biopsy was based on sextant assessment of all cancer foci following sextant-by-sextant matching and reconstruction. Sensitivity/specificity of positron emission tomography/computerized tomography and magnetic resonance imaging for prediction of extraprostatic extension was also assessed. RESULTS: Positron emission tomography/computerized tomography showed 83% sensitivity for localization of nodules 5 mm or greater. At logistic regression analysis only nodule size appeared to influence sensitivity. At sextant assessment positron emission tomography/computerized tomography had slightly better sensitivity than transrectal ultrasound guided biopsy (66% vs 61%, p = 0.434) but was less specific (84% vs 97%, p = 0.008). For assessment of extraprostatic extension, sensitivity of PET/CT was low in comparison with magnetic resonance imaging (22% vs 63%, p <0.001). CONCLUSIONS: Positron emission tomography/computerized tomography has good sensitivity for intraprostatic localization of primary prostate cancer nodules 5 mm or greater. Positron emission tomography/computerized tomography and transrectal ultrasound guided biopsy show similar sensitivity for localization of any cancer focus. Positron emission tomography/computerized tomography does not seem to have any role in extraprostatic extension detection. Studies of diagnostic accuracy (as opposed to tumor localization) are needed in patients with suspected prostate cancer to see whether positron emission tomography/computerized tomography could have a role in not selected patients.     

The clinical advances of fluorine‐2‐D‐deoxyglucose – positron emission tomography/computed tomography in urological cancers

Fluorine‐18 labeled fluorine‐2‐D‐deoxyglucose (FDG) is the most frequently used positron emission tomography (PET) probe but it has certain limitations when used in urological cancers. The introduction of co‐registered PET and computed tomography (PET/CT) represents a major advance in technology and FDG‐PET/CT has now become the new standard. The diagnostic performance of FDG‐PET and PET/CT depends on the metabolic activity of tumor tissue, which is generally low in primary renal cell and prostate cancers and often in their metastatic deposits. In contrast, both seminomatous and nonseminomatous germ cell tumors are characterized by upregulated glucose metabolism with subsequently increased FDG uptake in tumor sites. Generally, the metabolic activity provides accurate information regarding the presence of a viable tumor, except in patients with residual mature teratoma. Although bladder cancer demonstrates sufficiently increased FDG uptake, primary tumors are difficult to identify due to the renal excretion of FDG. The accuracy of FDG‐PET/CT in metabolically active metastases is generally higher compared to conventional CT except for identifying small lung deposits. With disease progression and subsequent de‐differentiation of prostate cancer, castrate resistant disease is more likely to present with lesions that have increased glucose metabolism.     

Results of the American College of Surgeons Oncology Group Z0050 trial: the utility of positron emission tomography in staging potentially operable non-small cell lung cancer

OBJECTIVES: The American College of Surgeons Oncology Group undertook a trial to ascertain whether positron emission tomography with 18F-fluorodeoxyglucose could detect lesions that would preclude pulmonary resection in a group of patients with documented or suspected non-small cell lung cancer found to be surgical candidates by routine staging procedures. METHODS: A total of 303 eligible patients registered from 22 institutions underwent positron emission tomography after routine staging (computed tomography of chest and upper abdomen, bone scintigraphy, and brain imaging) had deemed their tumors resectable. Positive findings required confirmatory procedures. RESULTS: Positron emission tomography was significantly better than computed tomography for the detection of N1 and N2/N3 disease (42% vs 13%, P =.0177, and 58% vs 32%, P =.0041, respectively). The negative predictive value of positron emission tomography for mediastinal node disease was 87%. Unsuspected metastatic disease or second primary malignancy was identified in 18 of 287 patients (6.3%). Distant metastatic disease indicated in 19 of 287 patients (6.6%) was subsequently shown to be benign. By correctly identifying advanced disease (stages IIIA, IIIB, and IV) or benign lesions, positron emission tomography potentially avoided unnecessary thoracotomy in 1 of 5 patients. CONCLUSIONS: In patients with suspected or proven non-small cell lung cancer considered resectable by standard staging procedures, positron emission tomography can prevent nontherapeutic thoracotomy in a significant number of cases. Use of positron emission tomography for mediastinal staging should not be relied on as a sole staging modality, and positive findings should be confirmed by mediastinoscopy. Metastatic disease, especially a single site, identified by positron emission tomography requires further confirmatory evaluation.     

Positron emission tomography in the initial staging of esophageal cancer

OBJECTIVE: To assess the value of positron emission tomography (PET) compared with computed tomography (CT) in the initial staging of esophageal cancer. DESIGN: Case series. SETTING: Tertiary care veterans hospital. PATIENTS: Patients with newly diagnosed esophageal cancers from January 1996 through May 2001 who underwent both CT and PET scanning within 4 weeks were included in the study (n = 24). Only patients who underwent pathological or radiographic follow-up were included. MAIN OUTCOME MEASURES: The sensitivity, specificity, and negative and positive predictive values of CT and PET were determined based on a criterion standard of pathological staging in 16 patients (67%) and follow-up imaging in 8 patients (33%). RESULTS: For staging regional lymph node involvement, CT and PET scans showed no statistically significant difference in sensitivity (57% and 71%, respectively) and specificity (71% and 86%, respectively). For detection of metastatic disease, CT and PET showed no significant difference in sensitivity (83% and 67%, respectively) and specificity (75% and 92%, respectively). There was no significant difference in clinical decision making when the results of both tests were discordant. CONCLUSIONS: There was no significant difference between the 2 imaging modalities in the initial staging of esophageal cancer. The CT scan was a sensitive indicator of distant metastases, whereas PET was more specific. It is unclear what additional role PET scanning should have in the initial screening of patients.     

Role of PET/CT in muscle-invasive bladder cancer

The purpose of this study covered the diagnostic accuracy and usefulness of positron emission tomography/computed tomography (PET/CT) imaging in muscle invasive bladder cancer patients through previously published literature. Through 30 September, 2019, the PubMed database was searched for eligible articles that evaluated PET/CT imaging in bladder cancer patients. In general, FDG PET/CT, the most commonly used PET/CT imaging, does not show good performance for the detection of primary lesions; however, according to the literature it could accurately assess pelvic lymph node (LN) status better than other imaging technologies and it was especially helpful in determining extra-pelvic recurrences. More recently, non-FDG PET/CT imaging, such as C-11 acetate and C-11 choline, has been introduced. Although further research is required, preliminary results show the potential of these techniques to overcome the drawbacks of FDG. This concise study will overview the role of PET/CT when treating muscle-invasive bladder cancer (MIBC).     

Positron emission tomography is superior to computed tomography for metastatic detection in melanoma patients

BACKGROUND: Whole-body positron emission tomography (PET) provides diagnostic information not currently available with traditional imaging and may improve the accuracy of staging melanoma patients. METHODS: A retrospective cohort review was performed of 104 patients with primary or recurrent melanoma who underwent PET to determine sensitivity/specificity for metastatic detection compared with body computed tomography (CT). One hundred fifty-seven PET and 70 CT scans were analyzed, with a median patient follow-up of 24 months. Metastases were confirmed with positive histology (87.5%) or documented disease progression (12.5%). Fifty-three patients prospectively underwent consecutive studies within a mean 3-week interval for direct comparative analysis. RESULTS: PET demonstrated 84% sensitivity (95% confidence interval [CI],.78 to.89) and 97% specificity (95% CI,.91 to.99), whereas CT showed 58% sensitivity (95% CI,.49 to.66) and 70% specificity (95% CI,.51 to.84). Exclusion of areas not evaluated on CT (head, neck/supraclavicular, extremities) increased CT sensitivity to 69% (95% CI,.59 to.77). Sixty-six consecutive PET and CT scans were performed with 81% and 57% of metastases detected, respectively. CONCLUSIONS: PET is more sensitive and specific than CT for detection of melanoma metastasis and should be considered the primary staging study for recurrent disease. PET shows greater ability to detect soft tissue, small-bowel, and lymph node metastasis that do not meet criteria designated as abnormal by CT. PET is superior to CT even when sites not routinely evaluated by CT are excluded from comparative analysis.     

PET和CT对结直肠癌复发、转移诊断价值的评估

目的：评价PET和CT诊断复发转移性结直肠癌的价值。方法：结直肠癌病人94例行PET检查，其中67例同时行CT检查。以病理或随访为最后诊断，平均随访时间为21个月。^18F-FDG-PET的诊断结果基于医师的肉眼判断、SUV值（the standard uptake value）和CT图像三者结果而得出的。结果：PET和CT检查真阳性分别为46例和32例，真阴性25例和14例，假阳性5例和7例，假阴性4例和10例。PET和CT的符合率88．75％和73．02％、灵敏度92．00％和76．19％，特异性83．33％和66．67％，阳性预测值90．20％和82．05％，阴性预测值86．21％和58.33％。两者诊断符合率和灵敏度差异具有统计学意义P值分别为0．015和0．034。PET对临床处理的影响率为12．5％（n=10）。结论：PET结合常规诊断方法可有效地提高结直肠癌复发转移病灶诊断的准确性。     

18F] 3-deoxy-3'-fluorothymidine positron emission tomography: alternative or diagnostic adjunct to 2-[18f]-fluoro-2-deoxy-D-glucose positron emission tomography in the workup of suspicious central focal lesions?

BACKGROUND: 2-[(18)F]-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography has been established as a standard diagnostic imaging method in the preoperative workup of suspicious pulmonary focal lesions, showing a sensitivity of more than 90% and a specificity of about 80%. Determination of malignant pulmonary lesions with FDG positron emission tomography depends on the assessment of glucose metabolism. However, false-positive findings can occur in inflammatory processes, such as sarcoidosis or pneumonia. The thymidine analogue 3-deoxy-3[(18)F]-fluorothymidine (FLT) is a new positron emission tomography tracer that more specifically targets proliferative activity of malignant lesions. The objective of this study was to determine whether FLT positron emission tomography, in comparison with FDG positron emission tomography, provides additional information in the preoperative workup of central pulmonary focal lesions. METHODS: In this prospective study FLT and FDG positron emission tomography examinations were performed as a part of the preoperative workup in 20 patients with histologically confirmed bronchial carcinoma, 7 patients with benign lesions, and 1 patient with an atypical carcinoid. Results were compared with final pathologic findings. RESULTS: For staging of the primary tumor, FLT positron emission tomography revealed a sensitivity of 86% and a specificity of 100% compared with a sensitivity of 95% and a specificity of 73% for FDG positron emission tomography. For N staging, the sensitivity of FLT positron emission tomography was 57% and the specificity was 100%, and for FDG positron emission tomography, the sensitivity was 86% and the specificity was 100%, respectively. CONCLUSIONS: Our preliminary findings indicate specific FLT uptake in malignant lesions. The number of false-positive findings in FDG positron emission tomography might be reduced with FLT positron emission tomography. Therefore positron emission tomography imaging with FLT represents a useful supplement to FDG in assessing the malignancy of central pulmonary focal lesions.     

High-resolution fluorodeoxyglucose positron emission tomography with compression ("positron emission mammography") is highly accurate in depicting primary breast cancer

We sought to prospectively assess the diagnostic performance of a high-resolution positron emission tomography (PET) scanner using mild breast compression (positron emission mammography [PEM]). Data were collected on concomitant medical conditions to assess potential confounding factors. At four centers, 94 consecutive women with known breast cancer or suspicious breast lesions received 18F-fluorodeoxyglucose (FDG) intravenously, followed by PEM scans. Readers were provided clinical histories and x-ray mammograms (when available). After excluding inevaluable cases and two cases of lymphoma, PEM readings were correlated with histopathology for 92 lesions in 77 women: 77 index lesions (42 malignant), 3 ipsilateral lesions (3 malignant), and 12 contralateral lesions (3 malignant). Of 48 cancers, 16 (33%) were clinically evident; 11 (23%) were ductal carcinoma in situ (DCIS), and 37 (77%) were invasive (30 ductal, 4 lobular, and 3 mixed; median size 21 mm). PEM depicted 10 of 11 (91%) DCIS and 33 of 37 (89%) invasive cancers. PEM was positive in 1 of 2 T1a tumors, 4 of 6 T1b tumors, 7 of 7 T1c tumors, and 4 of 4 cases where tumor size was not available (e.g., no surgical follow-up). PEM sensitivity for detecting cancer was 90%, specificity 86%, positive predictive value (PPV) 88%, negative predictive value (NPV) 88%, accuracy 88%, and area under the receiver-operating characteristic curve (Az) 0.918. In three patients, cancer foci were identified only on PEM, significantly changing patient management. Excluding eight diabetic subjects and eight subjects whose lesions were characterized as clearly benign with conventional imaging, PEM sensitivity was 91%, specificity 93%, PPV 95%, NPV 88%, accuracy 92%, and Az 0.949 when interpreted with mammographic and clinical findings. FDG PEM has high diagnostic accuracy for breast lesions, including DCIS.     

Evaluation of fluorodeoxyglucose positron‐emission tomography with computed tomography for staging of urothelial carcinoma

Study Type – Diagnostic (case series)
Level of Evidence 4

OBJECTIVE

To investigate the role of ¹⁸F‐fluorodeoxyglusose positron‐emission tomography (FDG‐PET), combined with computed tomography (CT) and forced diuresis, in the staging and follow‐up of urothelial carcinoma (UC).

PATIENTS AND METHODS

We recruited 44 patients with muscle‐invasive urothelial bladder cancer (UBC) before radical cystectomy (RC), 19 under follow‐up after RC and seven after systemic chemotherapy. For those who had RC, histopathology was used as the reference standard to compare the sensitivity and specificity of FDG‐PET/CT and standard CT in detecting UBC and pelvic lymph node metastasis. Furthermore, 36 patients with ≥6 months of follow‐up imaging were considered to describe the progression of UC and extrapelvic positive FDG‐PET/CT images.

RESULTS

For the detection of primary UBC, FDG‐PET/CT was slightly more sensitive than CT (85% vs 77%) but less specific (25% vs 50%). For the detection of pelvic node metastasis FDG‐PET/CT was more sensitive than CT (57% vs 33%) with a specificity of 100% for both imaging techniques. In 20 patients, extrapelvic FDG‐PET/CT images showed suspected disease at the first evaluation. UC progressed in nine of the 10 patients who had synchronous multiple PET‐positive retroperitoneal or mediastinal lymph nodes, and in only two of the nine with unique hyperactive lesions in the lung. FDG‐PET/CT also detected a pT1G3 UC of the renal pelvis and all bone metastases detected by bone scintigraphy.

CONCLUSIONS

FDG‐PET/CT could replace standard CT and bone scintigraphy in the presurgical staging and monitoring of patients with UC after surgery or chemotherapy.     

Update on positron emission tomography for imaging of prostate cancer

Prostate cancer is the most common non‐cutaneous malignancy among men in the Western world, and continues to be a major health problem. Imaging has recently become more important in the clinical management of prostate cancer patients, including diagnosis, staging, choice of optimal treatment strategy, treatment follow up and restaging. Positron emission tomography, a functional and molecular imaging technique, has opened a new field in clinical oncological imaging. The most common positron emission tomography radiotracer, ¹⁸F‐fluorodeoxyglucose, has been limited in imaging of prostate cancer. Recently, however, other positron emission tomography tracers, such as ¹¹C‐acetate and ¹¹C‐ or ¹⁸F‐choline, have shown promising results. In the present review article, we overview the potential and current use of positron emission tomography or positron emission tomography/computed tomography imaging employing the four most commonly used positron emission tomography radiotracers, ¹⁸F‐fluorodeoxyglucose, ¹¹C‐acetate and ¹¹C‐ or ¹⁸F‐choline, for imaging evaluation of prostate cancer.     

Clinical use of fluorodeoxyglucose F 18 positron emission tomography for detection of renal cell carcinoma

PURPOSE: We evaluate the role of fluorodeoxyglucose F 18 positron emission tomography (PET) in patients with renal cell carcinoma (RCC) by retrospective review. To our knowledge this series is the largest reviewing the use of PET in patients with RCC. MATERIALS AND METHODS: A total of 66 patients who underwent 90 PET scans for suspected or known RCC were identified. Dictated reports of PET, chest computerized tomography (CT), abdominal/pelvic CT and bone scan were examined with confirmation of results by histopathology or followup of at least 1 year. The accuracies of PET and conventional imaging modalities were compared. RESULTS: PET exhibited a sensitivity of 60% and specificity of 100% for primary RCC tumors (abdominal CT demonstrated 91.7% sensitivity and 100% specificity). For retroperitoneal lymph node metastases and/or renal bed recurrence, PET was 75.0% sensitive and 100.0% specific (92.6% sensitivity and 98.1% specificity for abdominal CT). PET had a sensitivity of 75.0% and a specificity of 97.1% for metastases to the lung parenchyma compared to 91.1% and 73.1%, respectively, for chest CT. PET had a sensitivity of 77.3% and specificity of 100.0% for bone metastases, compared to 93.8% and 87.2% for combined CT and bone scan. In 39 scans (32 patients) PET failed to detect RCC lesions identified by conventional imaging. CONCLUSIONS: The role of fluorodeoxyglucose F 18 PET in the detection of RCC is limited by low sensitivity. With superior specificity PET may have a complementary role as a problem solving tool in cases that are equivocal on conventional imaging.     

Impact of F18-fluorodeoxyglycose positron emission tomography/computed tomography on the management of resectable pancreatic tumours

Background: Positron emission tomography/computed tomography (PET/CT) using F18‐fluorodeoxyglucose has been shown to be valuable in the management of malignant disease. The aim of this study is to investigate the impact of this technique on the management of patients with resectable pancreatic tumours. Methods: Thirty‐six patients with 37 potentially resectable pancreatic tumours on diagnostic CT imaging underwent PET/CT scans. Operative findings, histological reports and/or clinical follow‐up served as standard of reference. The impact of PET/CT on patient management was estimated by calculating the percentage of patients whose treatment plan was altered due to PET/CT. Results: Pancreatic adenocarcinoma was diagnosed in 30 patients, neuroendocrine tumours in 3, mass‐forming pancreatitis in 3 and serous cystadenoma in 1. The median standard uptake (max) value was 5.0 (range 2.2–12.0). Sensitivity and specificity of detecting extrapancreatic metastatic disease were 73% and 100%, respectively. Three occult liver metastases were detected at laparotomy following negative PET/CT. PET/CT findings influenced the management of 8 (22%) patients – 3 with liver metastases, 3 with bone metastases, 1 with lymph node metastases and 1 by identifying the benign appearance of the pancreatic tumour. Conclusion: PET/CT achieves a significant diagnostic impact in detecting extrapancreatic metastatic disease. F18‐fluorodeoxyglucose PET/CT appears to be useful in assessing suspicious pancreatic masses.     

Fluorodeoxyglucose positron emission tomography for detection of recurrent or metastatic breast cancer

Fluorodeoxyglucose-positron emission tomography (FDG-PET) is a noninvasive imaging technique capable of identifying primary tumors and metastases with high sensitivity and accuracy. The aim of this study was to evaluate the diagnostic accuracy of whole-body FDG-PET imaging for the detection of recurrent or metastatic breast cancer after surgery. Whole-body FDG-PET imaging was performed on 27 patients with suspected recurrent breast carcinoma. PET images were evaluated qualitatively for each patient and lesion. FDG-PET scans showed that there were 61 reference sites of malignant or benign lesions in 27 patients. In a patient-based analysis, FDG-PET scans correctly identified 16 of 17 patients with recurrent or metastatic disease and 8 of 10 without recurrence, resulting in a sensitivity, specificity, and accuracy of 94%, 80%, and 89%, respectively. In a lesion-based analysis, FDG-PET scans correctly identified 46 of 48 lesion sites with recurrent or metastatic disease and 11 of 13 without recurrence. The overall sensitivity, specificity, and accuracy for all lesion sites were 96%, 85%, and 93%, respectively. FDG-PET scans revealed unsuspected recurrent or metastatic diseases in 8 of 27 (30%) of patients and 11 of 20 (55%) distant metastatic lesions. In 13 patients treatment was altered by the outcome of the PET scan. We concluded that whole-body FDG-PET scan is a useful diagnostic imaging modality for detecting recurrent or metastatic breast carcinoma in patients suspected of having recurrent disease after primary surgery.     

Combined contrast-enhanced computed tomography and 18-fluoro-2-deoxy-D-glucose-positron emission tomography in the diagnosis and staging of non-small cell lung cancer

We present the current optimal uses and limitations of positron emission tomography/computed tomography (PET/CT) as it relates to the diagnosis and staging of non-small cell lung cancer (NSCLC). PET/CT demonstrates increased accuracy in the workup of solitary pulmonary nodules for malignancy compared with CT alone, and we discuss its benefits and limitations. We review pitfalls in measured standardized uptake values of lung lesions caused by respiratory artifacts, the lower sensitivity for detection of small lung nodules on non-breath-hold CT, and the benefits of obtaining an additional diagnostic CT for the maximum sensitivity of lung nodule detection. There are limitations of quantitatively comparing separate PET/CT examinations from different facilities with standardized uptake values. As for staging, we describe how PET/CT supplements clinical tumor-nodes-metastases (ie, TNM) staging, as well as mediastinoscopy, endobronchial ultrasound, and endoscopic ultrasound, which are the gold standard pathologic staging methods. We touch on the 7th edition TNM staging system based on the work by the International Association for the Study of Lung Cancer, an anatomically based staging method.     

The size of metastatic foci and lymph nodes yielding false-negative and false-positive lymph node staging with positron emission tomography in patients with lung cancer

BACKGROUND: We examined the sizes of lymph nodes and metastatic foci within the lymph nodes that affect false-positive and false-negative lymph node staging by positron emission tomography in lung cancer. METHODS: Preoperative positron emission tomography and computed tomography scans were performed for 564 lymph node stations in 80 patients with peripheral-type lung cancer. The sizes of both the lymph nodes and the metastatic foci within the lymph nodes were measured, and these measurements were compared with those obtained with positron emission tomography scanning. To establish general sizes of metastatic foci within the lymph nodes, 277 metastatic lymph nodes in operative specimens previously resected from another 111 patients with lung cancer were examined as a control. RESULTS: The sensitivity was significantly higher for positron emission tomography than for computed tomographic scanning (P =.026). The sizes of metastatic foci within lymph nodes that showed false-negative (n = 8) and true-positive (n = 28) with positron emission tomography ranged from 0.5 to 9 mm (3 +/- 1 mm) and from 4 to 18 mm (10 +/- 3 mm), respectively (P <.001). None of the metastatic foci smaller than 4 mm could be detected with positron emission tomography scanning. The review of the 277 previously resected metastatic lymph nodes showed that 89 (32%) had metastatic foci smaller than 4 mm. The sizes of true-positive (n = 28) and false-positive (n = 10) lymph nodes ranged from 6 to 15 mm (10 +/- 2 mm) and from 9 to 16 mm (12 +/- 2 mm), respectively (P <.01). None of the false-positive lymph nodes was smaller than 9 mm. CONCLUSIONS: Although positron emission tomography was superior to computed tomography scanning in lymph node staging in lung cancer, positron emission tomography was unable to distinguish metastatic foci smaller than 4 mm, which were not unusual sizes for lymph node metastases in lung cancer. Positive lymph nodes with positron emission tomography smaller than 9 mm are likely to be true-positive rather than false-positive.     

Contribution of 11C-choline positron emission tomography/computerized tomography to preoperative staging of advanced transitional cell carcinoma

PURPOSE: Current imaging modalities for preoperative staging of advanced transitional cell carcinoma of the bladder or upper urinary tract are not sensitive for detection of metastases. This study examines the contribution of 11C-choline positron emission tomography/computerized tomography to preoperative staging of transitional cell carcinoma. MATERIALS AND METHODS: We prospectively evaluated 18 patients with 19 advanced transitional cell carcinomas (17 bladder tumors and 2 upper tract transitional cell carcinomas). All patients had computerized tomography of the chest, abdomen and pelvis negative for metastases. 11C-choline positron emission tomography/computerized tomography was performed on a Discovery ST(R) positron emission tomography/computerized tomography system. Finally 16 patients underwent radical surgery and positron emission tomography/computerized tomography images were compared to histopathological findings. Two patients were not operated on due to the findings on 11C-choline positron emission tomography/computerized tomography. RESULTS: 11C-choline uptake was found in all primary transitional cell carcinomas, with a maximum standardized uptake value of 7.3 +/- 3.2 (mean +/- SD). The series included 3 patients with refractory bladder carcinoma in situ, which was visualized in all 3, with a standardized uptake value of 6.9 +/- 5.6. In 6 patients uptake of 11C-choline in lymph nodes as small as 5 mm was visualized (standardized uptake value 3.8 +/- 1.4). Of these patients 4 underwent surgery and histopathology confirmed malignancy in 3 of 4. No additional patients with positive lymph nodes were found on histopathology. Metastases were visualized in bones with normal architecture on computerized tomography in 4 patients (standardized uptake value 5.2 +/- 1.1) and were confirmed by followup computerized tomography. CONCLUSIONS: In this small series 11C-choline positron emission tomography/computerized tomography was highly sensitive for primary and metastatic transitional cell carcinoma. Carcinoma in situ, lymph node metastases and early bony metastases were visualized. 11C-choline positron emission tomography/computerized tomography is a promising tool for preoperative staging of advanced transitional cell carcinoma.     

Fluorodeoxyglucose positron emission tomography integrated with computed tomography to determine resectability of primary lung cancer

PURPOSE: Fluorodeoxyglucose positron emission tomography integrated with computed tomography (FDGPET/CT) was evaluated as a routine staging technique for primary lung cancer. MATERIALS AND METHODS: We prospectively compared FDG-PET/CT in determining clinical stage and surgical indication with conventional staging not including positron emission tomography (PET). A total of 50 consecutive patients diagnosed with primary lung cancer by cytological or histological examination were studied; 20 of them underwent surgery. RESULTS: Discrepancies between the two staging methods were observed in 14 patients (28%). The stage assigned by PET increased in 12 cases (24%) and decreased in 2 (4%). PET staging was accurate in eight cases with otherwise undetected distant metastases (M1) but was incorrect in six cases, including five where it overdiagnosed nodal metastases (N). Two clinical N3 patients (4%) would have missed a chance of surgery if the surgical indication had been determined by PET staging alone. According to our criteria for surgery, other patients were assigned correctly to surgery by PET staging. The maximum standard uptake value (maxSUV) of all primary lesions ranged from 0 to 23.0 (mean +/- SD, 8.0 +/- 4.4). The mean maxSUV among surgical cases (5.8 +/- 3.6) was significantly smaller than among nonsurgical cases (9.5 +/- 4.2) (P < 0.05). CONCLUSION: Staging examination including FDG-PET/CT and brain magnetic resonance imaging ordinarily can determine the clinical stage and resectability of primary lung cancer. False-positive findings in regional lymph nodes, possibly reflecting past infectious disease, are the most important remaining problem.     

Usefulness of single photon emission computed tomography imaging in the detection of lumbar vertebral metastases from prostate cancer

Objective:   To determine whether single photon emission computed tomography (SPECT) is useful in the detection of prostate cancer bone metastases in the lumbar vertebrae.
Methods:   Thirty-nine patients (12 with benign prostatic hyperplasia, 27 with prostate cancer) were considered and submitted to bone SPECT. All of them had increased uptake in lumbar vertebrae on bone scintigraphy. In those with prostate cancer, definitive diagnosis of bone metastases was established by magnetic resonance imaging (MRI). SPECT axial images were classified into five accumulation patterns: mosaic, large hot, diffuse, peripheral, and articular (or pediculate). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of bone SPECT were calculated.
Results:   Overall, 116 vertebral lesions (49 metastatic, 67 degenerative) were studied. Mosaic, large hot and diffuse patterns were more frequently associated with metastatic lesions (84.2%, 70.3%, and 63.1% of the cases, respectively). On the other hand, peripheral and articular (or pediculate) patterns were mostly ascribed to degenerative lesions (100% and 87.5% of the cases, respectively). Sensitivity, specificity, PPV and NPV of bone SPECT were 95.9% (47/49), 73.1% (49/67), 72.3% (47/65), and 96.1% (49/51), respectively.
Conclusions:   Bone SPECT provides better accuracy than bone scintigraphy in differential diagnosis of lumbar vertebral lesions from prostate cancer.     

Evaluation of fluorodeoxyglucose positron emission tomography imaging in metastatic transitional cell carcinoma with and without prior chemotherapy

INTRODUCTION: This study was designed to determine the value of fluorodeoxyglucose (FDG) positron emission tomography (PET) in the evaluation of metastatic transitional cell carcinoma (TCC). METHODS: Fifty-eight FDG PET scans were performed on 46 consecutive patients with TCC. Results were correlated with radiologic, pathologic, and histologic findings in these patients and the sensitivity of PET for detecting malignancy in untreated TCC patients (n = 48) was compared to the sensitivity in patients who had undergone prior chemotherapy (n = 10). RESULTS: Of 48 scans in patients who had no prior systemic chemotherapy, 10 had increased uptake in proven metastatic TCC lesions and 3 PET studies failed to reveal metastatic TCC (sensitivity 76.9%). In patients free of metastatic disease, 33 revealed no abnormal uptake and 1 study revealed a suspicious area in a patient free of metastases (specificity = 97.1%). However, in 10 patients imaged after receiving chemotherapy, the sensitivity fell to 50% for the detection of histologically confirmed residual/recurrent tumor by PET. CONCLUSIONS: FDG PET detects increased metabolic activity. After chemotherapy, viable cancer cells may still be present but with a diminished metabolic rate. As a result, PET imaging is often useful in the evaluation of untreated metastatic TCC metastasis but should be interpreted with caution in patients who have received prior chemotherapy.