Higher SUVmax Values Research Articles

Increased FDG uptake in breast cancer is associated with prognostic factors

To evaluate the relationship between FDG uptake and prognostic factors of breast cancer such as hormone receptors (estrogen and progesterone), expression of c-erbB-2, axillary lymph node status, tumor histology, grade and size. Between May 2009 and February 2011; 79 patients (mean age ± SD: 52.9 ± 13.9 years) with biopsy proven breast cancer underwent F-18 FDG PET/CT scanning for staging. Patients with excisional biopsy or neoadjuvant chemotherapy were excluded from the study. Histological types included were invasive ductal carcinoma (n = 68), invasive lobular carcinoma (n = 2), and invasive ductal plus lobular mixed carcinoma (n = 9). Maximum standardized uptake values (SUVmax) were compared with estrogen (ER) and progesterone receptors (PR), expression of c-erbB-2, as well as tumor grade and tumor size. For the evaluation of relationship between tumor SUVmax values and prognosticators such as hormone receptors, tumor histologic grade, and tumor size, statistical analyses were performed using Student t test, Mann-Whitney U Test and Pearson correlation coefficient and p values of less than 0.05 were considered to indicate statistically significant differences. All primary breast neoplasms were detected by PET/CT scanner. The mean SUVmax values and breast cancer tumor sizes ranged from 2.09 to 39.0 and 0.7 to 10 cm, respectively. Tumors with negative ER [(n = 19); SUVmax median (min-max): 15 (2.09-39.0)] were associated with higher SUVmax values (p = 0.01). Tumors with overexpression of C-erbB-2 [(n = 28); SUVmax median (min-max): 16.0 (5.0-39.0)]; tumor grade 3 [(n = 25); SUVmax median (min-max): 15 (6.43-39)]; axillary lymph node involvement [(n = 60); SUVmax median (min-max): 13.61 (4.0-39.0)]; tumor histopathology and increased tumor size were associated with higher maximum standardized uptake values. However, PR did not show any relationship with SUVmax values. In the present report, strong relationships were detected between the negativity of ER, overexpression of c-erbB-2, tumor grade, tumor size, histopathology, axillary lymph node involvement and SUVmax values. Accordingly, we believe that SUVmax values obtained with (18)F-FDG PET/CT may provide some information about tumor biology of breast cancer.

Can the Pathology of a Thyroid Nodule Be Determined by Positron Emission Tomography Uptake?

To determine if standardized uptake values (SUV) on positron emission tomography (PET) are predictive of thyroid pathology and the significance of serial SUV measurements of thyroid nodules over time. Case series with chart review. Academic health center. In total, 23,384 PET and PET/computed tomography (CT) scans were performed between December 2001 and April 2011. Patients with incidental thyroid uptake were identified. SUV(max), age, sex, size of thyroid lesion, indication for PET scan, and cytology/pathology were collected. Incidental thyroid uptake was noted in 1309 PET scans (5.60%), focal uptake in 690 (2.95%), and diffuse uptake in 619 (2.65%). Complete data were available for 359 PET scans from 103 patients. Malignancy was identified in 28 patients (27%). Twenty-five of the 28 lesions (89%) were primary thyroid malignancies. A significant difference between malignant SUV(max) and benign SUV(max) was found (mean ± SD, 7.04 ± 7.88 for malignancies vs 3.85 ± 3.06 for benign tumors, P = .0292). Receiver operating characteristics curves were constructed on patients with PET data within 3 months of diagnosis and indicated that a SUV(max) of 4.2 differentiated maximally between benign and malignant lesions. Serial SUV uptake had no significant change over time. All thyroid nodules with focal uptake on (18)F-fluorodeoxyglucose-PET/CT should be considered at higher risk of malignancy than those discovered incidentally by other imaging modalities. Higher SUV(max) values are more indicative of malignant lesions. All lesions should be evaluated with ultrasonography ± fine-needle aspiration if no clinical contraindications exist. Size of the primary nodule does not influence SUV(max) uptake.

Current status of Radiologic Diagnosis for Mediastinal Lymph Node Metastases of Non-Small-Cell Lung Cancer: Retrospective Study of pN2 Cases

Objective: Advances in diagnostic imaging techniques, such as 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), have led to greater accuracy in preoperative mediastinal staging for patients with non-small-cell lung cancer (NSCLC), but surgical staging remains the “gold standard” for diagnosis. A proper understanding of the current accuracy of diagnostic imaging is needed for further improvements. Methods: Forty-three patients who underwent resection for NSCLC involving mediastinal lymph node (MLN) metastasis at our hospital between June 2003 and May 2011 were enrolled in this study. We conducted a retrospective study of the radiological and pathological findings for 53 metastatic MLNs in the 43 patients. Results: The preoperative imaging modality was computed tomography (CT) alone for 18 patients (22 MLNs) and CT and FDG-PET for 25 patients (31 MLNs). The sensitivities of CT and FDG-PET were 41.5% and 58.0%, respectively. The sensitivity of CT did not differ according to any clinicopathological factors, but the sensitivity of FDG-PET tended to be higher for primary tumors with high SUVmax values and for non-adenocarcinomas. In the lymph nodes, all micrometastatic foci ≤ 2 mm were PET-negative, but 4 lymph nodes with metastatic foci larger than 10 mm were also PET-negative. Conclusions: For the diagnostic imaging of MLN, FDG-PET has a greater sensitivity than contrast-enhanced CT based on “size criteria”, but it is still not sufficiently sensitive and is influenced by various factors. At present, histological confirmation of MLNs is necessary when making decisions regarding treatment plans and the type of surgical procedure that should be performed.

The Role of PET-CT in Evaluation of Solitary Pulmonary Nodules

Introduction: The solitary pulmonary nodule (SPN) may be an early sign of lung cancer. Due to the difficulties of radiological imaging techniques in differentiation of benign/malignant nodules, functional imaging techniques like PET-CT are required in patients diagnosed with SPN. The aim of this study was the evaluation of the role of PET-CT in differentiation of malignant/benign SPN by some characteristic findings in PET-CT. Moreover, among the nodules with histopathologically diagnosed as benign, malignant or metastatic, the SUVmax and Hounsfield Units (HU) of PET-CT imaging were also aimed to be compared to assess the role of PET-CT in discrimination of malignant/ benign SPN. Material and Method: Among the patients evaluated with PET-CT with the pre-diagnosis of pulmonary nodule or non-pulmonary malignancies, between July 2010 and January 2012, in Konya University Meram Medical School Nuclear Medicine Department, 241 patients (167 male, 74 female) diagnosed with pulmonary nodule were enrolled in the study. In visual evaluation of PET-CT of all patients, there was only one nodule in lung parenchyma. The diameter in cm, location as central or peripheral, regularity of borders, presence of calcification and HU and Maximum standardized uptake values (SUVmax) values with quantitative analysis of all nodules was recorded. The histopathological evaluation of nodules was available in 91 of those 241 patients and they were also recorded. Results: In comparison of mean SUVmax values in regards to the characteristic findings of nodules in PET-CT, the mean SUVmax value of patients was statistically significantly higher in patients with the nodule diameter ≥ 1cm, centrally located nodules, or nodules with irregular borders. Conclusion: In malignant/benign differentiation of solitary pulmonary nodules with the diameter of higher than 1 cm, PET-CT plays an essential role; however, for the nodules smaller than 1 cm in diameter, in small, single metastatic nodules and some benign nodules with high SUVmax values, PET-CT may be unsatisfactory. However, it is clear that, in especially undetermined nodules, PET-CT is an important complementary tool in diagnosis.

Imaging Findings of Invasive Micropapillary Carcinoma of the Breast

PurposeThe purpose of this study is to evaluate imaging and histopathologic findings including the immunohistochemical characteristics of invasive micropapillary carcinoma (IMPC) of the breast.MethodsTwenty-nine patients diagnosed with IMPC were included in the present study. Mammographic, sonographic, and magnetic resonance imaging (MRI) findings were analyzed retrospectively according to the American College of Radiology Breast Imaging Reporting and Data System lexicon. 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) findings were also evaluated. Microscopic slides of surgical specimens were reviewed in consensus by two pathologists with a specialty in breast pathology.ResultsMost IMPCs presented as a high density irregular mass with a non-circumscribed margin associated with microcalcifications on mammography, as an irregular hypoechoic mass with a spiculated margin on ultrasound, and as irregular spiculated masses with washout patterns on MRI. PET-CT showed a high maximum standardized uptake value (SUVmax) (mean, 11.2). Axillary nodal metastases were identified in 65.5% of the patients. Immunohistochemical studies showed high positivities for estrogen receptor and c-erbB-2 (93.1% and 51.7µ, respectively).ConclusionEven though the imaging characteristics of IMPCs are not distinguishable from typical invasive ductal carcinomas, this tumor type frequently results in nodal metastases and high positivities for both estrogen receptor and c-erbB-2. The high SUVmax value that is apparent on PET-CT might be helpful in the diagnosis of IMPC.

Detection of incidental colorectal tumours with 18F-labelled 2-fluoro-2-deoxyglucose positron emission tomography/computed tomography scans: results of a prospective study

This study assessed the clinical significance of incidental colorectal 2-fluoro-2-deoxyglucose (FDG) uptake using (18) F-FDG positron emission tomography/computed tomography (PET/CT) scans and evaluated the importance of colonoscopy when incidental colorectal FDG uptake was observed. A prospective study was designed and conducted at a single institution over a 2-year period. In patients undergoing PET/CT scans, all with FDG uptake in the colorectum were assigned to have colonoscopy and biopsy. The value of PET/CT scanning was studied by comparison with the colonoscopy and biopsy results. Among 10,978 PET/CT scans, one or more focal uptakes of FDG in the colorectum were observed in 148 (1.35%) patients. In 136 valid patients, malignant colorectal tumours and polyps were found in 23.5% and 20.5%, respectively,, while the colon in the other 56% was normal. A higher false-positive rate was found in the right colon compared with the distal colorectum (66.2%vs 36.7%, P = 0.004). A significant increase of the maximum standardized uptake (SUVmax) value was found among normal, polyps and cancer groups. Multivariate analysis revealed that SUVmax was the risk factor for predicting colorectal cancer or polyps and FDG uptake in the right colon was a negative predictive factor for finding cancers or polyps. Our study proves the necessity of colonoscopy when incidental FDG uptake is found on PET/CT imaging. The false-positive FDG uptake is more commonly observed in the right colon. Although the SUVmax value is higher in cancer patients, a high SUVmax value does not necessarily result in malignancies.

18F-FDG PET patterns and BAL cell profiles in pulmonary sarcoidosis

Bronchoalveolar lavage (BAL) and (18)F-fluorodeoxyglucose ((18)F-FDG) PET can both demonstrate sarcoid activity. To assess whether metabolic activity imaged by (18)F-FDG PET represents signs of disease activity as reflected by BAL, (18)F-FDG PET patterns were compared with BAL cell profiles. In this retrospective analysis, 77 newly diagnosed pulmonary sarcoidosis patients underwent BAL and (18)F-FDG PET. Based on (18)F-FDG PET, patients were diagnosed with exclusively mediastinal/hilar activity (group A) and activity in the lung parenchyma (group B). Per group, BAL lymphocytes (%), CD4/CD8 ratio, CD103(+)CD4(+)/CD4(+) ratio and neutrophils (%) were compared with the extent of metabolic activity expressed as the maximum standardized uptake value (SUV(max)). Additionally, SUV(max) and BAL parameters per radiographic stage were analysed. Overall, the SUV(max) in the lung parenchyma correlated with neutrophils and SUV(max) of the mediastinum/hila correlated with the CD4/CD8 ratio. In both groups, a significant, negative correlation between the SUV(max) of the mediastinum/hila and the CD103(+)CD4(+)/CD4(+) ratio was found. In group B, the SUV(max) of the mediastinum/hila correlated with the CD4/CD8 ratio, while the SUV(max) in the lung parenchyma correlated with the CD103(+)CD4(+)/CD4(+) ratio and neutrophils. Significant differences were found in the SUV(max), CD4/CD8 ratio, CD103(+)CD4(+)/CD4(+) ratio and neutrophils between the radiographic stages. The SUV(max) of the lung parenchyma was positively related to the radiographic stage, while the SUV(max) of the mediastinum/hila and CD4/CD8 ratio were inversely related. (18)F-FDG PET correlates with the CD4/CD8 ratio and neutrophils, suggesting that (18)F-FDG PET represents this specific cell profile in BAL. High SUV(max) values of the lung parenchyma may therefore correlate with more severe parenchymal involvement, particularly when accompanied by a low SUV(max) of the mediastinum/hila.

Tumor necrosis in osteosarcoma: inclusion of the point of greatest metabolic activity from F-18 FDG PET/CT in the histopathologic analysis.

To determine if the location of the point of maximum standardized uptake value (SUVmax) being included in or not included in the histopathologic slab section corresponded to tumor necrosis or survival. Twenty-nine osteosarcoma patients underwent post-chemotherapy [fluorine-18]-fluoro-2-deoxy-D: -glucose (FDG) positron-emission tomography-computed tomography (PET/CT) prior to resection. PET/CT images were correlated with slab-section location as determined by photographs or knowledge of specimen processing. The location of the point of SUVmax was then assigned as being 'in' or 'out' of the slab section. Cox's proportional hazard regression was used to evaluate relationships between the location and value of SUVmax and survival. Logistic regression was employed to evaluate tumor necrosis. No correlation was found between the SUVmax location and survival or tumor necrosis. High SUVmax correlated to poor survival. High SUVmax value correlated to poor survival. Minimal viable tumor (> 10%) following chemotherapy is a known indicator of poor survival. No correlation was found between the location of SUVmax and survival or tumor necrosis. Therefore, the SUVmax value either does not correspond to a sufficient number of tumor cells to influence tumor necrosis measurement or it was included in the out-of-slab samples that were directed to viable-appearing areas of the gross specimen. Since high SUVmax has been previously found to correspond to poor tumor necrosis, and tumor necrosis is simply an estimate of the amount of viable tumor, SUVmax likely represents many viable tumor cells. Therefore, when not in the slab section, SUVmax was likely included in the tumor necrosis measurement through directed sampling, validating our current method of osteosarcoma specimen analysis.

Comparison of primary tumor maximal standardized uptake value (SUVmax) on preoperative [18F]fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and histological subtype in patients with non-small cell lung cancer (NSCLC)

7571 Background: The routine preoperative use of PET/CT in patients with potentially resectable NSCLC is rapidly expanding. The SUVmax is a semiquantitative measure of metabolic activity that can distinguish benign from malignant tissue but published data are conflicting regarding its ability to discriminate between major histological subtypes. Methods: Pathology and PET/CT reports of 39 NSCLC patients who underwent a preoperative scan and curative resection at the McGill University Health Centre were reviewed. Only patients with Adenocarcinoma (AC), Squamous Cell carcinoma (SC), or Large Cell carcinoma (LC), and definitive pathological staging, were included. The SUVmax values for each histological subtype, along with primary tumor sizes, were compared using F test and t-test analyses. Results: The 15 patients with SC and 5 with LC histology were found to have significantly greater preoperative SUVmax values than the 19 patients with AC (mean 12.7 and 17.2 vs. 9.4, respectively, P < 0.05), despite the fact that no significant differences in tumor size were observed between histological subtypes. Patients with LC histology displayed higher SUVmax values than patients with SC histology, but this was not found to be significant (P = 0.057).Conclusions: These data suggest that SC pulmonary tumors have significantly greater uptake on PET/CT than AC tumors. This finding may be helpful in the future when sufficient tissue cannot be obtained for pathological diagnosis or to identify the predominant pathology of mixed tumors. Larger studies are required to confirm our results. [Table: see text] No significant financial relationships to disclose.

Prospective Evaluation of FDG-PET Imaging of Treatment Response in Relapsed Follicular Lymphoma.

Follicular lymphoma is the most common low-grade lymphoma and incurable with conventional therapies. In recent years, increased use of FDG-PET (PET) scanning in aggressive lymphomas has led to its application in follicular lymphoma, despite a lack of information on its predictive value. We undertook a prospective study to evaluate PET scanning prior to and following therapy (tx) in relapsed follicular lymphoma patients. Eligibility criteria included follicular grade I or II disease in 1st or 2nd relapse, with planned tx for at least stage 2 disease. Pre- and post-tx PET and CT scans were read by different blinded radiologists. 24 pts were enrolled; of these, two were ineligible and one was later found to have lung cancer. 21 pts were therefore analyzed. The median age at diagnosis was 57 (34–72), with a median time from diagnosis to pre-treatment PET scan of 2.8 yrs (0.6–9.0); 15 pts were in 1st relapse (71%), and 13 had follicular grade 1 (62%). By clinical staging, 4 were stage 2 (19%), 8 stage 3 (38%) and 9 stage 4 (43%). PET resulted in upstaging compared to CT in 5 pts (24%), 3 due to bone lesions and 2 due to nodal sites; however 3 of these 5 pts were also upstaged by bone marrow biopsy. The median of the highest SUVmax on the pre-tx PET scans was 12.1 (1.9–20.7). The mean SUVmax of all identified lesions on each pre-tx PET scan had a median value of 5.7 (1.9–8.4). A trend toward a correlation between the highest SUVmax on the initial PET scan and the bidimensional area of the largest CT lesion was observed (p=0.059). The tx received during the study included chemotherapy for 8 pts (38%) and antibody tx for 13 pts (62%). The objective response rate using Cheson criteria was 52%, with 5 CR/CRu, 6 PR, 7 SD and 3 PD. Using EORTC PET response criteria, 4 CR, 12 PR, 1 SD and 1 PD were observed. Thus 84% had evidence of response by PET, but 79% remained PET positive on their post-tx scan. The median value of the highest residual SUVmax on the post-tx scans was 5.13 (0.5–18.1); no correlation of residual SUVmax and bidimensional area of the largest residual CT lesion was observed. At 1-year follow-up, 48% of pts have relapsed, with a median time to relapse of 0.7 years (0.07–1.6). No pt who was PET negative on the post-tx scan has relapsed; of these 4 pts, 3 were also CRs by CT, and one had SD by CT criteria. PFS was not predicted by age, stage, or follicular subtype; a trend toward shorter PFS for pts in 2nd relapse was observed (p=0.055). Of CT and PET measures on initial and post-tx scans, only a residual SUVmax ≥ 5 predicted shorter PFS (p=0.0009); bidimensional area of the largest residual CT lesion was not predictive of PFS. Among pts with PR by PET criteria, CT responses by Cheson criteria (CRu, PR, SD) were not predictive of PFS (p=0.18). We conclude that PET imaging is highly sensitive for detection of follicular lymphoma, which commonly has high SUVmax values. A large fraction of relapsed follicular NHL pts who respond to tx by standard criteria have evidence of residual disease on FDG-PET, and positive lesions with SUVmax ≥ 5 are associated with a shorter PFS. The overall value of FDG-PET imaging in the management of pts with relapsed follicular lymphoma remains to be determined.