Biomedical subjects

Hilmar Kuehl

Publications and source records attributed to Hilmar Kuehl.

At least 19 recordsLinked to original sources

PubMed2007

Can PET/CT replace separate diagnostic CT for cancer imaging? Optimizing CT protocols for imaging cancers of the chest and abdomen.

Stage-adapted treatment in oncology relies on correct tumor staging for patients with malignant diseases. To ensure accurate assessment of the tumor stage in thoracic and abdominal diseases by PET/CT, both CT and PET need to be optimized. In this setting, different malignant diseases require customized imaging protocols. Although in the clinical setting of therapy assessment, PET/CT with integration of low-dose, nonenhanced CT may be sufficient, tumor staging may require a more sophisticated CT protocol. This review focuses on potential CT protocols for imaging cancers of the chest and abdomen. Examples of CT protocols are presented and discussed for non-small cell lung cancer, breast cancer, colorectal cancer, gastrointestinal stromal tumors, and interventional liver therapy.

Abdominal Neoplasms↗

PubMed2006

Diagnostic accuracy of colorectal cancer staging with whole-body PET/CT colonography.

CONTEXT: Staging of patients with colorectal cancer often requires a multimodality, multistep imaging approach. Colonography composed of a combined modality of positron emission tomography (PET) and computed tomography (CT) provides whole-body tumor staging in a single session. OBJECTIVES: To determine the staging accuracy of whole-body PET/CT colonography compared with the staging accuracies of CT followed by PET (CT + PET) and CT alone and to evaluate the effect of PET/CT colonography on therapy planning compared with conventional staging (CT of the abdomen and thorax and optical colonoscopy). DESIGN, SETTING, AND PATIENTS: Prospective study of 47 patients enrolled between May 2004 and June 2006 with clinical findings and optical colonoscopy that suggested primary colorectal cancer (mean [SD] age, 71 [11] years; range, 47-92 years). Patients underwent whole-body PET/CT colonography 1 day after colonoscopy. The study was conducted at a university hospital with a mean (SD) follow-up of 447 (140) days (range, 232-653 days). MAIN OUTCOME MEASURES: Correct classification of overall TNM stage using PET/CT colonography compared with CT + PET and CT alone. Secondary outcome measures were the accurate assessment of T-stage, N-stage, and M-stage by PET/CT colonography compared with CT + PET and CT alone and the effect of PET/CT colonography on therapy planning. RESULTS: Of the 47 patients with a total of 50 lesions, the overall TNM stage was correctly determined for 37 lesions with PET/CT colonography (74%; 95% confidence interval [CI], 60%-85%), 32 lesions with CT + PET (64%; 95% CI, 49%-77%), and 26 lesions with CT alone with a 0.7-cm node threshold (52%; 95% CI, 37%-66%). Compared with optimized abdominal CT staging alone, PET/CT colonography was significantly more accurate in defining TNM stage (difference, 22%; 95% CI, 9%-36%; P=.003), which was mainly based on a more accurate definition of the T-stage. Differences were not detected for defining N-stage between PET/CT colonography and CT alone with a threshold of 0.7 cm for malignant nodes but were detected with a threshold of 1 cm. Differences were not detected in defining M-stage separately or when comparing the accuracies of PET/CT colonography with CT + PET. PET/CT colonography affected consecutive therapy decisions in 4 patients (9%; 95% CI, 2.4%-20.4%) compared with conventional staging (CT alone and colonoscopy). CONCLUSIONS: In this preliminary study, PET/CT colonography is at least equivalent to CT + PET for tumor staging in patients with colorectal cancer. Thus, PET/CT colonography in conjunction with optical colonoscopy may be a suitable concept of tumor staging for patients with colorectal cancer.

Aged↗

PubMed2006

Accuracy of combined PET/CT in image-guided interventions of liver lesions: an ex-vivo study.

AIM: Positioning of interventional devices in liver lesions is a challenging task if only CT is available. We investigated the potential benefit of combined PET/CT images for localization of interventional devices in interventional liver studies. METHODS: Thirty lesions each of hyperdense, isodense and hypodense attenuation compared to normal liver parenchyma were injected into 15 ex-vivo pig livers. All lesions were composed of the same amounts of gelatine containing 0.5 MBq of (18)F-FDG. Following lesion insertion, an interventional needle was placed in each lesion under CT-guidance solely. After that, a PET/CT study was performed. The localization of the needle within the lesion was assessed for CT alone and PET/CT and the root mean square (RMS) was calculated. Results were compared with macroscopic measurements after lesion dissection serving as the standard of reference. RESULTS: In hypo- and isodense lesions PET/CT proved more accurate in defining the position of the interventional device when compared with CT alone. The mean RMS for CT and PET/CT differed significantly in isodense and hypodense lesions. No significant difference was found for hyperdense lesions. CONCLUSION: Combined FDG-PET/CT imaging provides more accurate information than CT alone concerning the needle position in FDG-PET positive liver lesions. Therefore combined PET/CT might be potentially beneficial not only for localization of an interventional device, but may also be beneficial for guidance in interventional liver procedures.

Animals↗

PubMed2006

Prevalence of pulmonary hypertension associated with severe acute respiratory distress syndrome: predictive value of computed tomography.

OBJECTIVE: To evaluate the prevalence of pulmonary hypertension associated with severe acute respiratory distress syndrome (ARDS) and to asses the value of pulmonary artery trunk diameter (PAT) to predict pulmonary hypertension. DESIGN: Prospective study SETTING: University teaching hospital and ARDS referral center. PATIENTS: 103 patients with ARDS, who received both right heart catheterization and chest computed tomography. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: 95 patients (92.2%) with ARDS had pulmonary artery hypertension, 16 of them (16.8%) mild, 72 (75.8%) moderate, and 7 (7.4%) severe, as assessed by right heart catheterization. Of the patients with moderate and severe pulmonary hypertension, 43 had a pulmonary artery trunk diameter >or=29 mm yielding a sensitivity of 0.54 and a specificity of 0.63. Pulmonary artery trunk diameter correlated significantly but weakly with mean pulmonary artery pressure (r=0.34, p=0.0004). The positive predictive value was 0.83, and the negative predictive value was 0.28. The diagnosis of pulmonary hypertension by PAT diameter measurements was incorrect in 43.7% of patients with ARDS. CONCLUSIONS: Pulmonary artery hypertension has a high prevalence in patients with severe ARDS. Measurement of PAT diameter on admission CT scan is an unreliable tool for identification of ARDS patients with pulmonary hypertension.

Comorbidity↗

PubMed2006

Lymph node staging with dual-modality PET/CT: enhancing the diagnostic accuracy in oncology.

Lymph node staging according to the TNM criteria is an essential part of tumor evaluation. Several morphological and functional imaging procedures are used complementarily in this setting. Dual-modality PET/CT scanners are able to provide anatomical and functional data sets in a single session with accurate image co-registration. Comparative studies between morphological imaging procedures, such as MRI and CT, with co-registered PET/CT demonstrated significantly better lymph node staging with PET/CT than with anatomical procedures alone, regardless of the staged body compartment (head and neck, thorax or abdominal area). Based on more accurate staging results, PET/CT was able to alter the patients' therapy in a significant number of studies. Functional imaging with FDG-PET ([(18)F]-2-fluoro-2-desoxy-D-glucose-positron emission tomography) demonstrated outstanding results in lymph node staging of different tumor diseases. By adding anatomical information to PET, PET/CT outperforms PET alone when assessing the TNM-stage of different malignant diseases. This paper provides an overview concerning the performance of PET/CT in staging lymph nodes for malignant spread and points out benefits and limitations of this new imaging modality.

Contrast Media↗

PubMed2006

Evaluation of living liver donors with an all-inclusive 3D multi-detector row CT protocol.

PURPOSE: To prospectively assess parenchymal, vascular, and biliary anatomy of potential living liver donors with an all-inclusive multi-detector row computed tomographic (CT) approach. MATERIALS AND METHODS: A total of 250 potential living liver donors (112 women, 138 men; mean age, 37 years) underwent three-phase, dual-enhancement multi-detector row CT to delineate biliary, vascular, and parenchymal morphology according to an institutional review board-approved protocol. Informed consent was obtained from all subjects. For display of the biliary system, the first CT image set was collected after the infusion of a biliary contrast agent. CT angiography was subsequently performed, after automated injection of a conventional iodinated contrast agent, to display the arterial and portal-hepatic venous systems. All data sets were reconstructed in 1-mm sections. Data analysis was based on source images, multiplanar reconstructions, and three-dimensional postprocessing images; was performed in consensus by two radiologists; and was focused on the detection of biliary and vascular variants, exclusion of focal liver lesions, and determination of hepatic volumes. Preoperative findings were correlated with intraoperative findings (available in 62 subjects). RESULTS: Technical failures were experienced in 10 of 250 examinations. Twenty-seven subjects had moderate adverse reactions related to the biliary contrast agent. Benign hepatic lesions were detected in 61 candidates; one candidate had a renal cell carcinoma. Underlying biliary and vascular anatomy was displayed at least to the second intrahepatic branch in all but seven patients. Detected anatomic variants involved the biliary (38.8%), arterial (40.0%), portal venous (21.4%), and hepatic venous (43.5%) systems. Correlation with intraoperative findings was excellent. Some biliary (n = 4), arterial (n = 5), portal venous (n = 1), and hepatic venous (n = 6) variants were missed or misinterpreted at initial reading of preoperative data; however, variants could be retrospectively depicted in all but one biliary case and one hepatic venous case. CONCLUSION: The outlined three-phase, dual-enhancement multi-detector row CT protocol represents an all-inclusive approach to evaluate potential living liver donors in a single diagnostic step.

Adolescent↗

PubMed2006

Underlying aortic pathology and clinical health status determine success of endovascular stent-grafting for descending thoracic aortic disease.

Despite advances in medical and surgical treatment, acute as well as chronic diseases of the thoracic aorta are still associated with a high mortality. For the descending thoracic aorta, endovascular stent-graft placement competes with surgical therapy for clinical outcome. From July 1999 till December 2004, a total of 84 patients (64 +/- 14 years) with aortic disease of the descending thoracic aorta were treated. Nine patients had acute (AAD) and 35 chronic aortic dissection (AD), 16 had thoracic aortic aneurysms (TAA), 21 had penetrating aortic ulcer (PAU), and 3 patients had traumatic dissection (trans). Initial clinical status was assessed using the American Society of Anesthesiologists (ASA) classification. Fifty-three patients were in class 2, 16 in class 3, 8 in class 4, and 7 in class 5. Stent-graft placement was performed in the cardiac catheterization laboratory with the patient under general anesthesia. Technical success was obtained in 81/84 patients (96%). Within 30 days, seven patients (8%) died, four of them due to aortic rupture. In 14 patients, additional stent-grafts had to be implanted due to type I endovascular leakage (n = 5) or additional entry site adding up to a total of 107 implanted stent-grafts. During a follow-up period of 21 +/- 18 months, 17 additional patients died (22%). In 10 patients, death was disease- or procedure-related (13%). This long-term mortality depended on the underlying disease and was highest in the group with TAA (45%) followed by AAD (38%) and AD (18%). Patients in ASA class 4 and 5 had a significantly worse outcome. No aortic-related death occurred among patients with PAU or traumatic transsections. Overall, there was only one transient neurological deficit. Endovascular stent-graft placement has acceptable results in the treatment of patients with disease of the descending thoracic aorta. The outcome strongly depends on the underlying aortic pathology and the clinical health status of the patients. Randomized trials are necessary in order to establish the exact value of this new therapeutic option.

Adult↗

PubMed2005

Magnetic resonance imaging of autologous fat grafting.

A 30-year-old female patient with isolated facial lipodystrophy underwent two sessions of fat injection. MR signals of injected fat at different injection ages were compared to native fat. Native T1 signal was smaller for transplant fat, probably due to a slightly lower fat content and/or fibrosis or due to higher perfusion. T2 signal of transplants was significantly higher than that of native fat. T1 post-contrast was also higher, and contrast uptake of transplanted fat increased slightly with transplant age, which could be explained by an increasing perfusion. This study demonstrates the differences and MR signal time changes of native and transplanted fat.

Adipose Tissue↗

PubMed2005

Detection of residual tumor after radiofrequency ablation of liver metastasis with dual-modality PET/CT: initial results.

The aim of this study was to determine the accuracy of dual-modality positron emission tomography(PET)/computed tomography (CT) in the detection of residual tumor after radiofrequency ablation (RFA) of liver metastasis of colorectal cancer. Eleven patients with 16 hepatic metastases (mean size 2.9 cm) from colorectal cancer were enrolled in this study, and 19 RFA procedures and 32 PET/CT examinations were performed. The patients had PET/CT before and after RFA using [18F]-2-fluoro-2-deoxy-D: -glucose. CT images alone were read by two radiologists, PET images alone were evaluated by two nuclear physicians. Fused images were read by one physician of each speciality in consensus. The accuracy for detection of residual tumor by the different imaging modalities following RFA was assessed. Eleven patients with a mean age of 63 (range 55-71) years were evaluated. The mean follow-up period was 393 days. The overall procedure-based sensitivity for detection of residual tumor was 65% for PET and PET/CT and 44% for CT alone. The accuracies were 68% and 47%, respectively. Four patients had residual tumor after RFA, six patients total developed local recurrence. PET/CT therefore possibly proved superior to CT alone when assessing the liver for residual tumor after RFA.

Aged↗

PubMed2005

Interventional magnetic resonance angiography with no strings attached: wireless active catheter visualization.

Active instrument visualization strategies for interventional MR angiography (MRA) require vascular instruments to be equipped with some type of radiofrequency (RF) coil or dipole RF antenna for MR signal detection. Such visualization strategies traditionally necessitate a connection to the scanner with either coaxial cable or laser fibers. In order to eliminate any wire connection, RF resonators that inductively couple their signal to MR surface coils were implemented into catheters to enable wireless active instrument visualization. Instrument background to contrast-to-noise ratio was systematically investigated as a function of the excitation flip angle. Signal coupling between the catheter RF coil and surface RF coils was evaluated qualitatively and quantitatively as a function of the catheter position and orientation with regard to the static magnetic field B0 and to the surface coils. In vivo evaluation of the instruments was performed in interventional MRA procedures on five pigs under MR guidance. Cartesian and projection reconstruction TrueFISP imaging enabled simultaneous visualization of the instruments and vascular morphology in real time. The implementation of RF resonators enabled robust visualization of the catheter curvature to the very tip. Additionally, the active visualization strategy does not require any wire connection to the scanner and thus does not hamper the interventionalist during the course of an intervention.

Animals↗

PubMed2005

Nonoperative management of tracheobronchial injuries in severely injured patients.

PURPOSE: A rupture of the airway due to blunt chest trauma is rare, and treatment can prove challenging. Many surgeons suggest operative management for these kinds of injuries. Nonoperative therapy is reported only in exceptional cases. But there is still a lack of evidence from which to recommend surgical repair of these injuries as the first choice procedure. METHODS: We retrospectively analyzed the records of 92 multiple injured patients admitted to our trauma department between July 2002 and July 2003 for the incidence and management of tracheobronchial rupture (TBR). RESULTS: Five (5.4%) of 92 patients suffered from tracheobronchial injuries. The mean injury severity score was 38. There were three male and two female patients, with a mean age of 23 years. All patients had lesions <2 cm in size and were treated nonoperatively. One patient died from multiorgan failure, but the others recovered from TBR uneventfully. One patient developed acute pneumonia as a result of respirator therapy, but none of the patients had mediastinitis or tracheal stenosis within 3 months after injury. CONCLUSION: We believe that surgical treatment is not mandatory in patients with small to moderate ruptures, and such aggressive treatment may even have adverse effects, especially in patients with multiple injuries.

Adolescent↗

PubMed2005

Evaluation of integrated whole-body PET/CT in the detection of recurrent ovarian cancer.

PURPOSE: To assess the usefulness and reliability of integrated whole-body positron emission tomography/computed tomography (PET/CT) in patients in whom recurrent ovarian cancer is suspected. METHODS: Integrated whole-body PET/CT imaging was performed in 19 patients with suspected ovarian cancer recurrence. CT, PET and fused PET/CT images were evaluated separately and imaging results were compared with pathological findings and clinical follow-up after 6 months. RESULTS: Of the 19 patients studied, 11 were found to have recurrent cancer. In 8 of these 11 patients, recurrence was diagnosed by CT, PET and fused PET/CT. In the remaining three patients, only PET and PET/CT showed a recurrent tumour, while CT was negative. Twelve localisations of ovarian cancer recurrence could be detected by CT, 17 by PET and 18 by PET/CT. In one patient with pulmonary metastases in CT and in the CT component of PET/CT, PET was negative. In the case of three metastases in the diaphragm, the spleen and the thoracic wall, respectively, the determination of the exact localisation was only possible by fused PET/CT. CONCLUSION: In patients with recurrent ovarian cancer, PET/CT detects more lesions than PET or CT alone. PET/CT permits the exact anatomical localisation of pathologic tracer uptake and can thus direct further treatment to the precise site of tumour recurrence. Hence, PET/CT should be considered for follow-up of patients with ovarian cancer.

Aged↗

PubMed2005

Assessment of liver tissue after radiofrequency ablation: findings with different imaging procedures.

UNLABELLED: Our goal was to assess the typical appearance of normal liver tissue immediately after radiofrequency ablation (RF-ablation) when imaged with contrast-enhanced ultrasound, CT, MRI, 18F-FDG PET, and PET/CT. METHODS: Nineteen RF-ablation sessions were performed on nontumorous liver tissue of 10 Göttingen Mini Pigs. CT, ultrasound, MRI, 18F-FDG PET, and PET/CT were performed immediately after the intervention. All imaging procedures were evaluated qualitatively for areas of increased contrast enhancement (morphologic imaging) and regions of elevated tracer uptake (functional imaging). Images were assessed quantitatively by determination of ratios (r(p/p)) comparing contrast enhancement/tracer uptake in the periphery of the necrosis with contrast enhancement/tracer uptake of normal liver parenchyma. RESULTS: On morphologic imaging, an increase in contrast enhancement surrounding the ablative necrosis was detected in all lesions. Quantification of this area of increased contrast enhancement revealed ratios of r(p/p) = 1.57 +/- 0.2 for CT and r(p/p) = 1.57 +/- 0.19 for MRI. On PET and PET/CT, homogeneous tracer utilization was found surrounding all lesions. There were no areas of a focal or rim-like increase in glucose metabolism. The ratio r(p/p) was found to be 1.05 +/- 0.08 for functional data. Histologic examination revealed pooling of blood in the sinusoids of the lesion's periphery that was caused by outflow obstruction due to the central necrosis. CONCLUSION: On morphologic imaging, a rim-like increase of contrast enhancement was found immediately after RF-ablation resembling peripheral hyperperfusion. This area of contrast enhancement may hamper detection of residual tumor. On the basis of homogeneous tracer distribution surrounding the area of necrosis, PET and PET/CT may serve for early assessment of patients after RF-ablation.

Animals↗

PubMed2004

Accuracy of whole-body dual-modality fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography and computed tomography (FDG-PET/CT) for tumor staging in solid tumors: comparison with CT and PET.

PURPOSE: To assess the accuracy of positron emission tomography/computed tomography (PET/CT) when staging different malignant diseases. PATIENTS AND METHODS: This was a retrospective, blinded, investigator-initiated study of 260 patients with various oncological diseases who underwent fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT for tumor staging. CT images alone, PET images alone, PET + CT data viewed side by side, and fused PET/CT images were evaluated separately according to the tumor-node-metastasis system. One hundred forty patients with tumors not staged according to the tumor-node-metastasis system or a lack of reference standard were excluded from data analysis; 260 patients were included. Diagnostic accuracies were determined for each of the four image sets. Histopathology and a clinical follow-up of 311 (+/- 125) days served as standards of reference. RESULTS: PET/CT proved significantly more accurate in assessing tumor-node-metastasis system stage compared with CT alone, PET alone, and side-by-side PET + CT (P < .0001). Of 260 patients, 218 (84%; 95% CI, 79% to 88%) were correctly staged with PET/CT, 197 (76%; 95% CI, 70% to 81%) with side-by-side PET + CT, 163 (63%; 95% CI, 57% to 69%) with CT alone, and 166 (64%; 95% CI, 58% to 70%) with PET alone. Combined PET/CT had an impact on the treatment plan in 16, 39, and 43 patients when compared with PET + CT, CT alone, and PET alone, respectively. CONCLUSION: Tumor staging with PET/CT is significantly more accurate than CT alone, PET alone, and side-by-side PET + CT. This diagnostic advantage translates into treatment plan changes in a substantial number of patients.

Adolescent↗

PubMed2004

Intraoperative radiation therapy in liver tissue in a pig model: monitoring with dual-modality PET/CT.

PURPOSE: To assess, in a pig model, the value of dual-modality positron emission tomography (PET)/computed tomography (CT) for monitoring radiation therapy. MATERIALS AND METHODS: Central bile duct resection followed by creation of a biliodigestive anastomosis was performed in nine pigs. Six of these pigs were also treated with intraoperative radiation therapy (IORT) (20 Gy) in the area of the anastomosis. Two, 4, and 8 weeks postoperatively, contrast material-enhanced fluorine 18 fluorodeoxyglucose (FDG) PET/CT of the liver was performed in all of the animals. The radioactive tracer concentration in the region of the anastomosis was quantified, and the values were compared intraindividually with the values at the liver periphery. Histologic evaluation of the liver was performed 8 weeks postoperatively. The PET/CT images were assessed for changes in liver volume and bile duct diameter over time. RESULTS: In all nine pigs, the region of the anastomosis could be clearly defined on the fused PET/CT images. PET/CT revealed a decreased concentration of FDG in the irradiated field 2 and 4 weeks after IORT. At 8 weeks, however, the distribution of the tracer in the irradiated pigs did not differ from that in the nonirradiated pigs. Homogeneous tracer uptake in all liver regions was observed in the nonirradiated animals. The CT images showed an increase in liver volume in all pigs and bile duct dilatation that increased over time in the irradiated pigs. CONCLUSION: The morphologic and functional changes due to IORT in liver tissue can be accurately monitored with dual-modality PET/CT. By enabling the integration of functional and morphologic data, PET/CT may have an important role in monitoring radiation treatment.

Anastomosis, Roux-en-Y↗

PubMed2004

Dual-modality PET/CT scanning with negative oral contrast agent to avoid artifacts: introduction and evaluation.

The authors qualitatively and quantitatively assessed a solution containing 0.2% locust bean gum (LBG) and 2.5% mannitol (mannitol-LBG) dissolved in water to provide a negative oral contrast material in dual-modality positron emission tomography (PET)/computed tomography (CT) scanning. PET/CT was performed in 60 patients with cancer after oral administration of barium, water, or mannitol-LBG. Qualitative and quantitative analyses were conducted to determine bowel distention and a potential influence of the contrast agents on the PET data. Intestinal distention with mannitol-LBG proved superior to that with water or barium. Findings at both quantitative and qualitative analysis revealed apparently increased tracer uptake in the small bowel with barium in comparison to that with mannitol-LBG or water. Mannitol-LBG may, therefore, be used as a negative oral contrast agent at PET/CT scanning because it provides excellent bowel distention while avoiding contrast material-induced PET artifacts.

Administration, Oral↗

PubMed2004

Comparison of PET, CT, and dual-modality PET/CT imaging for monitoring of imatinib (STI571) therapy in patients with gastrointestinal stromal tumors.

UNLABELLED: This study was implemented to compare the value of PET, CT, and dual-modality PET/CT imaging for assessing gastrointestinal stromal tumor (GIST) response to imatinib therapy. METHODS: Twenty patients with histologically proven GIST underwent (18)F-FDG PET/CT imaging before and 1, 3, and 6 mo after the start of imatinib therapy. Separate PET and CT datasets, side-by-side PET and CT datasets, and fused PET/CT images were evaluated according to World Health Organization, Response Evaluation Criteria in Solid Tumors, and European Organisation for Research and Treatment of Cancer criteria for therapy response. Hounsfield units (HU) were assessed on CT images. A mean follow-up period of 381 +/- 134 d served as the standard of reference. RESULTS: The numbers of lesions detected in all patients were 135 with PET, 249 with CT, 279 on side-by-side evaluation, and 282 on fused PET/CT images. Tumor response was correctly characterized in 95% of patients after 1 mo and 100% after 3 and 6 mo with PET/CT. PET and CT images viewed side by side were correct in 90% of patients at 1 mo and 100% at 3 and 6 mo. PET accurately diagnosed tumor response in 85% of patients at 1 mo and 100% at 3 and 6 mo. CT was found to be accurate in 44% of patients at 1 mo, 60% at 3 mo, and 57% at 6 mo. HU were found to decrease by at least 25% in 12 of 14 responders after 1 mo. CONCLUSION: Tumor response to imatinib should be assessed with a combination of morphologic and functional imaging. Image fusion with combined PET/CT can provide additional information in individual cases when compared with side-by-side PET and CT.

Adult↗

PubMed2003

Non-small cell lung cancer: dual-modality PET/CT in preoperative staging.

PURPOSE: To determine the accuracy of dual-modality positron emission tomographic (PET)-computed tomographic (CT) imaging, as compared with PET alone and CT alone, in the staging of non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Twenty-seven patients with NSCLC underwent staging with combined fluorine 18 fluorodeoxyglucose PET and CT. CT, PET, and coregistered PET/CT images were evaluated separately by two different physicians for each imaging modality, and disease stage was determined by using TNM and American Joint Committee on Cancer staging systems. Histopathologic results served as the reference standard. The statistical significance of differences among CT, PET, and PET/CT was determined by using the McNemar test. RESULTS: Overall tumor stage was correctly classified as 0-IV with CT in 19 patients, with PET in 20 patients, and with PET/CT in 26 patients. PET/CT findings when compared with PET findings led to a treatment change for four patients (15%) and when compared with CT findings led to a treatment change for five patients (19%). Differences in the accuracy of overall tumor staging between PET/CT and CT (P =.008) and between PET/CT and PET (P =.031) were significant. Primary tumor stage was correctly determined in more patients with PET/CT than with either PET alone or CT alone. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of regional lymph node staging, respectively, were 89%, 94%, 89%, 94%, and 93%, with PET/CT; 89%, 89%, 80%, 94%, and 89% with PET; and 70%, 59%, 50%, 77%, and 63% with CT. Fourteen distant metastases were detected in four patients with CT, four were detected in two patients with PET, and 17 were detected in four patients with PET/CT. CONCLUSION: Use of dual-modality PET/CT significantly increases the number of patients with correctly staged NSCLC and thus has a positive effect on treatment.

Adult↗