Initial Standardized Uptake Value Research Articles

18F-FDG PET imaging for treatment response assessment and management guidance in patients with skull base osteomyelitis.

The objective of this study is to evaluate the role of hybrid 18F-FDG PET for treatment response assessment and management guidance in patients with skull base osteomyelitis. Retrospectively, 33 patients, with at least a baseline and follow-up PET (computed tomography/MRI) scan, were included. Parameters like standardized uptake value (SUV) max, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) (initial, follow-up, percentage change) were analysed and outcomes based on 18F-FDG PET reports were classified into resolution (a), partial response (b), progression (c) and stable disease (d). The clinical course and response on anatomical imaging were also compared with 18F-FDG PET. There was mild correlation between initial SUV with ESR (0.338) and CRP (0.384). Moderate correlation was seen between follow-up SUV and CRP (0.619), percentage change in SUV max (PC SUV) with percentage change in ESR (0.456) and CRP (0.668). Mean PC SUV was 70% (a), 35% (b), -40% (c) and -18% (d), respectively. 48% (16/33) (resolution, progression, stable disease) patients had clear management change with 18F-FDG PET with either escalation or stopping of antibiotics/antifungals. Management decision in partial response group (52%, 17/33) was taken clinically. On retrospective PC SUV analysis, treatment continuation group (8 patients) showed 20% decrease, whereas the group that was only monitored further (9 patients) had 48% reduction in SUV. 18F-FDG PET showed a moderate association with clinical markers used in follow-up of patients with skull base osteomyelitis and is a reliable investigation for assessment of disease status. This can be used as a guide along with clinical evaluation for de-escalation of treatment.

Evaluating Treatment Response of Radioembolization in Intermediate-Stage Hepatocellular Carcinoma Patients Using 18F-Fluoroethylcholine PET/CT.

The aim of this study was to evaluate (18)F-fluoroethylcholine PET/CT as a metabolic imaging technique for the assessment of treatment response to (90)Y radioembolization in patients with locally advanced hepatocellular carcinoma (HCC). Thirty-four HCC patients undergoing 78 (18)F-fluoroethylcholine PET/CT scans were identified for this study. Patients with initial or follow-up metastastic disease (n = 9) were excluded at the time point of the metastatic occurrence as well as patients with negative α-fetoprotein (AFP; n = 1), resulting in 24 patients and 57 scans that were eligible. All patients were scheduled for radioembolization and underwent 1 pretherapeutic and at least 1 posttherapeutic (18)F-fluoroethylcholine PET/CT scan. Volume-of-interest analysis and volume-of-interest subtractions were performed. Maximum, mean, and peak standardized uptake value (SUV) analysis was performed, and the total intrahepatic (18)F-fluoroethylcholine positive tumor volume (FEC-PTV) and tumor-to-background ratio were assessed. Statistical analysis was performed using a decreasing AFP of at least 20% as a standard of reference for therapy response including receiver-operating-characteristic analyses as well as descriptive and correlation analyses and multiple logistic regression. Fourteen follow-up examinations were categorized as responder and 19 follow-up examinations as nonresponder. Absolute AFP values did not correlate with SUV parameters (P = 0.055). In receiver-operating-characteristic analyses, the initial mean SUV, Δmaximum SUV, and Δtumor-to-background ratio demonstrated the highest area under the curve, 0.84 (P = 0.009), 0.83 (P = 0.011), and 0.83 (P = 0.012), respectively, resulting in a positive prediction of 82%, 83%, and 91% at the respective cutoff points. When multiple logistic regression analysis was applied, this resulted in an area under the curve of 0.90 (P = 0.001), with a positive prediction of 94% and a sensitivity of 94%. The FEC-PTV did not reach significance in the presented dataset. (18)F-fluoroethylcholine PET/CT demonstrates a high potential for follow-up assessment in the context of radioembolization in patients with locally advanced, but nonmetastatic, HCC and initially elevated AFP, possibly enabling early therapy monitoring independent of morphology.

Initial Standardized Uptake Value of Positron Emission Tomography Influences the Prognosis of Patients with Localized Gastric Adenocarcinoma Treated Preoperatively

Background: In patients with localized gastric adenocarcinoma (LGAC) who receive preoperative therapy, tools to predict response or prognosticate outcome before therapy are lacking. We used initial standardized uptake value (iSUV) of positron emission tomography (PET) to evaluate its association with overall survival (OS). Methods: We identified 60 patients with confirmed LGAC who were treated with preoperative chemoradiation and had a baseline PET in addition to other routine staging. Fisher's exact test and Wilcoxon's rank sum test were used to determine the association between iSUV and other variables, and the log-rank test and Cox proportional hazards model were used for survival analysis. Results: The median iSUV was 6 (range, 0-28). The presence of signet ring cells in pretreatment biopsies correlated highly with low iSUV (≤6; p = 0.0017). Patients with a high iSUV (>6) had a longer OS compared to those with a low iSUV (≤6; p = 0.0344). iSUV was not an independent predictor (p = 0.12); however, the risk of death was reduced for patients with an iSUV >6 (hazard ratio = 0.26). Conclusion: Our novel findings show that among LGAC patients treated with preoperative chemoradiation and surgery, those with a high iSUV have longer OS than patients with a low iSUV. iSUV appears to have a predictive role in patients with LGAC when treated with preoperative chemoradiation.

2254 Initial standardized uptake value (iSUV) of positron emission tomography (PET) influences prognosis of patients with localized gastric adenocarcinoma treated preoperatively

2254 Initial standardized uptake value (iSUV) of positron emission tomography (PET) influences prognosis of patients with localized gastric adenocarcinoma treated preoperatively

18F]fluorodeoxyglucose uptake as a predictor of large joint destruction in patients with rheumatoid arthritis.

The present retrospective study investigated the relationship between [(18)F]fluorodeoxyglucose-positron emission tomography (FDG-PET) findings and subsequent progression of joint destruction on plain X-ray. Nineteen rheumatoid arthritis (RA) patients (59 joints) who underwent FDG-PET and whose joints could be evaluated on plain X-ray 5 years later were included in this retrospective investigation. The relationship between the standardized uptake value (SUV) on FDG-PET and Larsen grade progression on plain X-ray was investigated for each joint. Factors related to progression of joint destruction were also investigated. Joints with advanced joint destruction (Larsen grades IV and V) on X-ray imaging at the time of FDG-PET were excluded. On initial plain X-ray images taken at the time of FDG-PET, a significant correlation was observed between the initial SUV of each joint and the progression of joint destruction 5 years later (R = 0.47, P < 0.01). Significant correlations between the SUV and progression of joint destruction were observed in both load-bearing (R = 0.52, P < 0.01) and non-load-bearing joints (R = 0.52, P < 0.01). On logistic regression analysis, higher SUV and lower prednisolone dose were associated with greater risk of progressive joint destruction (P < 0.05). On receiver operating characteristics curve analysis, the optimum threshold for identifying preceding joint destruction was an SUVmean of 1.33. In RA joints, FDG uptake was seen mostly by inflammatory cells; therefore, FDG uptake reflected joint inflammation. Additionally, the activity seen on FDG-PET might be associated with future radiographic changes in RA patients.

Clinical parameters’ model for predicting distant metastasis (DM) following definitive therapy in patients with localized esophageal and esophagogastric junction (E-EGJ) cancer.

89 Background: For localized E-EGJ cancer patients, chemoradiation followed by surgery (trimodality therapy [TMT]) or definitive chemoradiation (bimodality therapy [BMT]) are considered the standard of care. However, ˜30-40 % of patients with localized E-EGJ cancer develop DM. We hypothesized that a clinical parameters’ model can be established to predict DM. Methods: We analyzed E-EGJ cancer patients who completed TMT or BMT from our prospectively maintained database. Logistic regression models were used for analysis. Overall survival (OS) was estimated by the Kaplan-Meier method. We used the AJCC 6th edition. Results: Between 2002 and 2013, 356 TMT patients and 273 BMT patients were analyzed. 33% (119/356) of TMT patients and 40% (109/273) of BMT developed DM as a first relapse. The median OS from DM were 10.2 months (95% CI: 7.8-12.7) for TMT patients and 7.8 months (95% CI: 5.7-9.9) for BMT patients. In a logistic regression analysis for all patients, the following parameters were associated with a significantly increased risk of DM: age (odds ratio [OR]: 0.97 [95% CI: 0.96-0.99]), initial standardized uptake value (iSUV) of PET (OR: 1.02 [95% CI: 1.00-1.04]), Stage III/IVa (vs. I/II) (OR: 2.43 [95% CI 1.65-3.57]) and male (vs. female) (OR 3.99 [95% CI: 1.89-8.42]). For TMT patients, baseline T3/T4 (vs. T1/T2) (OR 2.75 [95%CI 1.10-6.86]), baseline N1 (vs. N0) (OR: 1.69 [95% CI: 1.03-2.77]), and poorly differentiated cancer (vs. well/moderately differentiated) (OR 1.78 [95% CI: 1.13-2.82]) were significantly associated with DM. Conclusions: Our data suggest that younger men with Stage III/IVa cancer and high iSUV are at risk for DM irrespective of local therapy (TMT or BMT). A nomogram to predict DM will be developed with a larger cohort. Supported by UT M. D. Anderson Cancer Center Multidisciplinary Research Grants, CA138671, CA172741, CA129926 from NCI (JAA) and Generous Donors.

Results of the baseline positron emission tomography can customize therapy of localized esophageal adenocarcinoma patients who achieve a clinical complete response after chemoradiation

BackgroundPatients with localized esophageal adenocarcinoma (EAC) who achieve a clinical complete response (clinCR) after preoperative chemoradiation (trimodality therapy; TMT) or definitive chemoradiation (bimodality therapy; BMT) live longer than those who achieve a <clinCR (Suzuki A, Xiao LC, Hayashi Y et al. Prognostic significance of baseline positron emission tomography and importance of clinical complete response in patients with esophageal or gastroesophageal junction cancer treated with definitive chemoradiotherapy. Cancer 2011; 117: 4823–4833; Cheedella NK, Suzuki A, Xiao L et al. Association between clinical complete response and pathological complete response after preoperative chemoradiation in patients with gastroesophageal cancer: analysis in a large cohort. Ann Oncol 2013; 24: 1262–1266; Ajani JA, Correa AM, Hofstetter WL et al. Clinical parameters model for predicting pathologic complete response following preoperative chemoradiation in patients with esophageal cancer. Ann Oncol 2012; 23: 2638–2642). We hypothesized that the initial standardized uptake value (iSUV) of positron emission tomography will define novel subsets of clinCR patients. MethodsWe analyzed 323 EAC patients, from our prospective database, who achieved a clinCR. Various statistical methods were used to assess the influence of iSUV on patient outcome. ResultsThe median follow-up of 323 patients was 40.8 months [95% confidence interval (CI) 35.6–47.3 months]. Two hundred six (63.8%) patients had TMT and 117 (36.2%) had BMT. If iSUV was ≥6, TMT patients had a longer median OS (94.8 months; 95% CI 66.07–NA) than BMT patients (31.4 months; 95% CI 21.7–42.1; P ≤ 0.001). However, if iSUV was <6, the median OS of TMT and BMT patients was similar (P = 0.62). iSVU did not influence the pathologic complete response rate in TMT patients (P = 0.85). ConclusionclinCR patients with iSUV of <6 are identified as a new subset that fared equally well when treated with TMT or BMT. Future esophageal preservation strategy may be best suited for this newly identified subset of EAC patients.

Breast Cancer Synchronism With Lung Cryptococcosis: A Case Report

Pulmonary metastasis is common among patients with breast cancer, and 18-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) is a useful diagnostic tool for identifying breast cancer with metastatic lesions. However, inflammation or infection can often interfere with diagnosis. We report on a 53-year-old female whose diagnosis included malignant breast cancer concurrent with lung cryptococcosis. A PET retention index greater than 10% has been used as a cutoff for malignancy; however, the retention index is not useful for differentiation if the initial standard uptake value is low. As such, a pathologic diagnosis should be considered. J Med Cases. 2013;4(9):605-607 doi: http://dx.doi.org/10.4021/jmc1406w

Positron Emission Tomography as a Surrogate Marker for Evaluation of Treatment Response in Patients with Desmoid Tumors under Therapy with Imatinib

We used 2-deoxy-2-[18F] fluoro-D-glucose (FDG) positron emission tomography (PET) to evaluate patients with desmoid tumors undergoing therapy with imatinib. The study included 22 patients with progressive disease (PD) of a biopsy proven desmoid tumor treated orally with imatinib 800 mg daily. Patients were examined using PET prior to onset of therapy and during treatment. Restaging was performed in parallel using computed tomography (CT) and/or magnetic resonance imaging (MRI). Outcome of 22 evaluable patients was as follows: five patients with partial response (PR); twelve patients with stable disease (SD) accounting for 77% with non-progressive disease; five patients showed PD. A 30% decrease of the mean average standardized uptake value (SUV) of sequential PET examinations could be demonstrated; no patient demonstrated a substantial increase in SUV. Patients with PR/SD were matched to a group of nonprogressive disease and tested versus PD. The initial average SUV and SUVmax seem to be candidates for a response prediction with an approximate P-value of 0.06553 and 0.07785, respectively. This is the first larger series of desmoid patients monitored using PET showing that early SUV changes may help to discriminate responders from nonresponders and, thus, to decide whether imatinib therapy should be continued.

FDG-PET/CT Metabolic Tumor Volume: A New Prognostic Marker in Hodgkin Lymphoma?

AbstractAbstract 3632 Introduction:Although Hodgkin Lymphoma (HL) is highly curable, about 15% of patients (pts) are refractory or relapsed after first line treatment. Classic prognostic scores (e.g. IPS) are useful for identifying high risk pts, who need intensive treatment, and low risk pts, who beneficiate de-escalation to minimize side effects. However, they are not enough suitable to predict outcomes. Consequently, finding new complementary tools for detecting refractory or relapsing pts, remains a challenge. Fluorodeoxyglucose (FDG)-PET/CT involvement in initial staging has been widely studied. Although clinical or CT tumor volume is an important prognostic factor, metabolic tumor volume (MTV) is not enough explored. We performed a study to 1) determine whether MTV and maximum standardized uptake value (SUV) max could be new prognostic markers and 2) compare metabolic tissue heterogeneity with CD68 expression, a promising new prognostic factor linked with inflammatory microenvironment. Patients and methods:Among 456 histologically proven HL pts registered in the Regional Lymphoma database of Limousin (SRRLL, France) since 1990’s, 158 have an available sample for CD68 staining. Among the 106 pts who have undergone FDG-PET, 43 pts have available quantitative initial and early response (post-C2) SUV FDG-PET/CT data. The median follow-up was 21 months (6–72.5). Pts were classified following Ann Arbor stages I: 4 pts, II: 17 pts, III: 9 pts, IV: 13 pts. FDG-PET/CT exams were performed with a biograph6 Siemens® device and analyzed with Siemens MI® application. MTV was computed for all pts with a 2D delineation technique and using a thresholding method. The threshold (T) corresponds to mean liver SUV (+3 sd) calculated into 50 cm3 of normal liver. All the tumor voxels (3D pixels) equal or greater than the T belong to MTV. MTV per pathological area (MTVa) was also analyzed. Pts with spleen lesions have an increased volume compared to the others. To minimize spleen’s impact, MTV was calculated without spleen (MTVws). Quantitative FDG uptake is routinely measured by SUVmax. The mean SUVmax was also worked out into 1 cm3 around the tumor SUVmax. ROC curves were plotted for continuous variables such as age, erythrocyte sedimentation rate (ESR), MTV, SUVmax and mean SUVmax. CD68, tumor associated macrophage expression, was tested with a 25% threshold for positivity. Significant factors allowed dividing pts into favorable and unfavorable groups. Event free survival (EFS) studies were carried out for all binary variables using COX model. A univariate regression analysis was performed. Variables with a p<0.20 were included in multivariate analysis. Results:Median age and sex ratio (n=43) were respectively 29 y-o (16–77) and 0.87. ROC and univariate analysis showed that MTV, MTVa and MTVws were significant predictors for absence of complete remission (CR) at post-C2 and EFS. Cut-off values for prognosis (Cp) were 310 cm3 for MTV or MTVws and 53 cm3 for MTVa (p<0.001). Cut-off values for post-C2 were 244 cm3 for MTV or MTVws and 62 cm3 for MTVa (p<0.007). For pts with a large tumor volume (MTV, MTVws or MTVa > Cp), 1 and 2 years EFS were shorter (figure1). Two years EFS for MTV, MTVa and MTVws are respectively: 40%, 50% and 21% for large tumor volume and 87%, 86% and 89% for small tumor volume (p= 0.004, p=0.01 and p=0.0003). The mean SUVmax and heterogeneity were significant in univariate analysis (p=0.01 and p=0.04) but not in ROC analysis. Heterogeneity level was not correlated with CD68 expression. Each new parameter was compared, in multivariate analysis, to ESR, stages, B symptoms, bulky, age. MTV was an independent factor for predicting outcomes and post-C2 results (p<0.01) and better than mean SUV max. Similar results were found for MTVa and MTVws (p<0.02 and p<0.01). Discussion:In spite of limited number of pts and short follow-up, prognostic value of MTV is very significant. Those data are in accordance with the few results previously reported (Hutchings et al. Int J Radiat Oncol Biol Phys, 2005). Song et al. (Cancer Science, 2012) also highlighted that MTV was better predictor than SUVmax in DLBCL. Conclusion:Large MTV seems to be a potential predictive marker for adverse post-C2 results and EFS. These data need further studies to confirm, in larger cohort, these first promising results to establish a better initial risk stratification of pts, leading to optimal adaptive therapy strategy. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

O2-037 - Initial Standardized Uptake Value (ISUV) of 18F-Fluorodeoxyglucose PET can Customize Treatment of Esophageal Adenocarcinoma (EAC) Patients who Achieve Clinical Complete Response (CCR) after Chemoradiation

ABSTRACT Background Patients with localized esophageal adenocarcinoma (EAC) receive preoperative chemoradiation followed by surgery (trimodality [TM] therapy) or definitive chemoradiotherapy (bimodality [BM] therapy) based on comorbidities and tumor geography. However, we cannot individualize recommendations beyond these parameters. We hypothesized that iSUV could customize therapy. Methods Data source was our prospective database of fully staged EAC patients (2002–2010). All patients had a cCR (post-chemoradiation negative biopsy and post-chemoradiation physiologic uptake on PET). iSUV cut-point was derived by recursive partitioning. Results For 323 cCR patients, the median follow-up was 40.8 months. 206 (63.8%) patients had TM and 117 (36.2%) had BM therapy. Median OS of TM patients and BM patients were 94.8 months (95% CI; NA–NA) and 36.5 months (95% CI; 30.5–42.4; P Conclusion Our unique data provide an insight into the fate of cCR EAC patients by iSUV. Patient with iSUV ≥6 dramatically benefit from surgery and TM therapy is encouraged. iSUV and pathCR do not correlate. iSUV can customize therapy of localized EAC patients.

Customization of treatment for patients with esophageal adenocarcinoma (EAC) who achieve clinical complete response (cCR) after chemoradiation using initial standardized uptake value (iSUV) of 18f-fluorodeoxyglucose PET.

4069 Background: Patients with localized esophageal adenocarcinoma (EAC) receive preoperative chemoradiation followed by surgery (trimodality [TM] therapy) or definitive chemoradiotherapy (bimodality [BM] therapy) based on comorbidities and tumor geography. However, we cannot individualize recommendations beyond these parameters. We hypothesized that iSUV could customize therapy. Methods: Data source was our prospective database of fully staged EAC patients (2002-2010). All patients had a cCR (post-chemoradiation negative biopsy and post-chemoradiation physiologic uptake on PET). iSUV cut-point was derived by recursive partitioning. Results: For 323 cCR patients, the median follow-up was 40.8 months. 206 (63.8%) patients had TM and 117 (36.2%) had BM therapy. Median OS of TM patients and BM patients were 94.8 months (95 % CI; NA-NA) and 36.5 months (95% CI; 30.5-42.4; p&lt;0.001), respectively. Similar differences were observed in RFS (p&lt;0.001). The median iSUV was 9.4 (range, 0-58.0). Intriguingly, TM patients with iSUV of &gt;6 had a better OS (94.8 months; 95% CI; 39.1-150.5) and RFS (94.8 months; 95% CI; 18.2-171.4) compared to BM patients with iSUV of &gt;6 OS (31.4 months; 95% CI; 21.0-41.9; p=&lt;0.001) and RFS (17.2 months; 95% CI; 14.5-19.8; p&lt;0.001). However, the prognosis of TM and BM cCR patients with iSUV &lt;6 was similar (OS, p=0.62 and RFS, p=0.46). The pathological CR (pathCR) rate in TM patients was similar irrespective of iSUV of ≥6 (27.1%) vs. iSUV &lt;6 (28.6%; p=0.85). Conclusions: Our unique data provide an insight into the fate of cCR EAC patients by iSUV. Patient with iSUV ≥6 dramatically benefit from surgery and TM therapy is encouraged. iSUV and pathCR do not correlate. iSUV can customize therapy of localized EAC patients.

Nomograms for Prognostication of Outcome in Patients with Esophageal and Gastroesophageal Carcinoma Undergoing Definitive Chemoradiotherapy

Introduction: Level-1 evidence for definitive chemoradiotherapy (bimodality therapy or BM therapy) has been established for patients with esophageal and gastroesophageal junction cancers (EGEJC) who otherwise do not qualify for surgery; however, tools to estimate individual patient prognosis are unavailable. We used a number of clinical pre- and post-treatment parameters to establish two nomograms: for overall survival (OS) and relapse-free survival (RFS). Methods: From 2002 through 2010, 257 consecutive patients with EGEJC who received BM therapy and had pre- and post-treatment positron emission tomography (PET) and post-treatment endoscopic biopsies among other assessments were analyzed from a prospectively maintained database. Standard statistical methods were used to generate the nomograms. Results: None of the 257 patients underwent surgery. Persistent or recurrent cancer was documented in 187 (72.8%) patients. The estimated median survival duration for all 257 patients was 21.1 months (95% CI, 18.9-27.1) and the median RFS duration was 11.6 months (95% CI, 9.43-15.0). After BM therapy, 155 (60.3%) patients achieved a clinical complete response (cCR). In multivariate analyses, maximum initial standardized uptake value and cCR were independent prognostic variables for OS (p = 0.038, p < 0.001). Nomogram concordance indices of 0.70 for OS and 0.77 for RFS were established by 200 cycles of bootstrap resampling for each of the two outcomes. Conclusion: Our data suggest that, in patients with EGEJC, pre- and post-treatment clinical parameters contribute to the establishment of prognostic nomograms of OS and RFS. Upon validation, these nomograms could prove useful in the clinic to individualize therapy.

Nomograms for prognostication of patients with esophageal and gastroesophageal carcinoma undergoing definitive chemoradiotherapy.

82 Background: Level-1 evidence for definitive chemoradiotherapy (bimodality therapy or BM therapy) has been established for patients with esophageal and gastroesophageal junction cancers (EGEJC) who otherwise do not qualify for surgery; however, tools to estimate individual patient’s prognosis are unavailable. We used a number of clinical pre-treatment and post-treatment parameters to establish two nomograms (for overall survival [OS] and relapse-free survival [RFS]). Methods: From 2002 through 2010, 257 consecutive patients with EGJEC who received BM therapy and had pre- and post-treatment positron emission tomography (PET) and post-treatment endoscopic biopsies among other assessments were analyzed from a prospectively maintained database. Standard statistical methods were used to generate the nomograms. Results: The median follow -up time was 39.2 months (95% confidence interval [CI], 35.7 – 50.1). None of 257 patients underwent surgery. Persistent or recurrent cancer was documented in 187 (72.8%) patients. The estimated median survival duration for all 257 patients was 21.1 months (95% CI, 18.9-27.1) and median RFS duration was 11.6 months (95% CI, 9.43-15.0). The estimated OS and RFS rates at 3 years were 37.3% (95% CI, 31.2%-44.7%) and 25.1% (95% CI, 19.9%-31.6%), respectively. After BM therapy, 155 (60.3%) patients achieved a clinical complete response (cCR). In the multivariate analyses, initial standardized uptake value maximum and cCR were independent prognostic variables for OS (P=0.038, P&lt;0.001). Nomogram concordance indices of 0.70 for OS and 0.77 for RFS were established by 200 bootstrap resampling for each of the two outcomes. Conclusions: Our data suggest that in patients with EGEJC, pre- and post-treatment clinical parameters contribute to the establishment of OS and RFS prognostic nomograms. Upon validated, these nomograms could prove useful in the clinic to individualize therapy.

The value of delayed (18)F FDG-PET imaging in diagnosis of solitary pulmonary nodules: A preliminary study on 28 patients.

The aim of this study was to investigate whether adding delayed phase imaging can improve diagnostic ability of (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) in evaluating solitary pulmonary nodules (SPNs). 28 patients with SPNs received dual-phase (18)F-FDG PET at 1h and 2h after (18)F-FDG injection during Feb 2009 to Jun 2011were included in this retrospective study. Their final diagnosis was confirmed by pathological examination in 27 cases and clinical follow-up in 1 case. The standardized uptake value (SUV) of early and delayed phases of all lesions was measured. The 28 SPNs included 9 benign lesions and 19 malignant lesions. Using SUV ≥2.5 as a criteria for malignancy, the sensitivity, specificity, and accuracy were 52.6%, 55.6% and 53.6% respectively at early phase; 68.4%, 55.6% and 64.3% respectively at early and delayed phases combined. Combined early and delayed phase scans combined picked up 3 additional malignant lesions from the 14 lesions with an initial SUV value less than 2.5, and there was no additional false positive result with the benign lesions. Adding delayed phase scanning resulted in correct diagnosis of three malignant lesions with an initial SUV value less than 2.5. Delayed phase scanning can be recommended in the SPNs with SUV less than 2.5 at early phase.

Early metabolic response using FDG PET/CT and molecular phenotypes of breast cancer treated with neoadjuvant chemotherapy

BackgroundThis study was aimed 1) to investigate the predictive value of FDG PET/CT (fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography) for histopathologic response and 2) to explore the results of FDG PET/CT by molecular phenotypes of breast cancer patients who received neoadjuvant chemotherapy.MethodsSeventy-eight stage II or III breast cancer patients who received neoadjuvant docetaxel/doxorubicin chemotherapy were enrolled in this study. FDG PET/CTs were acquired before chemotherapy and after the first cycle of chemotherapy for evaluating early metabolic response.ResultsThe mean pre- and post-chemotherapy standard uptake value (SUV) were 7.5 and 3.9, respectively. The early metabolic response provided by FDG PET/CT after one cycle of neoadjuvant chemotherapy was correlated with the histopathologic response after completion of neoadjuvant chemotherapy (P = 0.002). Sensitivity and negative predictive value were 85.7% and 95.1%, respectively. The estrogen receptor negative phenotype had a higher pre-chemotherapy SUV (8.6 vs. 6.4, P = 0.047) and percent change in SUV (48% vs. 30%, P = 0.038). In triple negative breast cancer (TNBC), the pre-chemotherapy SUV was higher than in non-TNBC (9.8 vs. 6.4, P = 0.008).ConclusionsThe early metabolic response using FDG PET/CT could have a predictive value for the assessment of histopathologic non-response of stage II/III breast cancer treated with neoadjuvant chemotherapy. Our findings suggest that the initial SUV and the decline in SUV differed based on the molecular phenotype.Trial RegistrationClinicalTrials.gov: NCT01396655

Molecular Imaging of Proliferation and Glucose Utilization: Utility for Monitoring Response and Prognosis after Neoadjuvant Therapy in Locally Advanced Gastric Cancer

Metabolic imaging of gastric cancer is limited due to the 30% of primary tumors that are not (18)F-fluorodeoxyglucose (FDG) avid. In contrast, the proliferation marker (18)F-fluorothymidine (FLT) has been shown to visualize also non-FDG-avid gastric tumors. In this study we tested whether FLT-positron emission tomography (PET) can improve the predictive potential of molecular imaging for assessing response to neoadjuvant therapy in gastric cancer compared with FDG-PET. 45 patients with gastric cancer underwent FDG- and FLT-PET before and 2 weeks after initiation of chemotherapy. FDG/FLT-PET findings and Ki67 immunohistochemistry were correlated with clinical and histopathological response and survival. 14 patients had non-FDG-avid tumors, whereas all tumors could be visualized by FLT-PET. No significant association of clinical or histopathological response with any of the analyzed metabolic parameters [initial standardized uptake value (SUV), SUV after 2 weeks, change of SUV for FDG/FLT] was found. Univariate Cox regression analysis for Ki67 and metabolic parameters revealed significant prognostic impact for survival only for FLT SUV(mean) day 14 (p=0.048) and Ki67 (p=0.006). Multivariate Cox regression analysis (including clinical response, Lauren type, ypN category, and FLT SUV(mean) day 14) revealed Lauren type and FLT SUV(mean) day 14 as the only significant prognostic factors (p=0.006, p=0.002). FLT uptake 2 weeks after initiation of therapy was shown to be the only imaging parameter with significant prognostic impact. Neither FLT-PET nor FDG-PET were correlated with histopathological or clinical response. However, these data must be interpreted with caution due to the single-center trial study design, relatively short follow-up, poor response rates, and unfavorable prognosis.

Prognostic significance of baseline positron emission tomography and importance of clinical complete response in patients with esophageal or gastroesophageal junction cancer treated with definitive chemoradiotherapy

Metabolic imaging is of interest in esophageal cancer; however, the usefulness of initial standardized uptake value (SUV) in positron emission tomography (PET) is unknown in patients with esophageal or gastroesophageal carcinoma treated with definitive chemoradiotherapy. The authors hypothesized that initial SUV would correlate with patient outcome. The authors retrospectively analyzed esophageal or gastroesophageal carcinoma patients who had baseline PET and endoscopic ultrasonography in addition to other routine staging. All patients received definitive chemoradiotherapy. Multiple statistical methods were used. The authors analyzed 209 consecutive esophageal or gastroesophageal carcinoma patients treated with definitive chemoradiation for outcome; of these, 180 had baseline PET for additional analyses. The median overall survival (OS) for all patients was 20.7 months (95% confidence interval, 18.8-26.3). Patients with clinical complete response (CR) lived longer than those with less than clinical CR (P < .0001). The median initial SUV was 12.7 (range, 0-51). Higher initial SUV was associated with longer tumors (P = .0001), higher T-stage status (P < .0001), positive N-stage status (P = .0001), higher overall stage (P < .0001), lack of clinical CR (P = .0002), and squamous cell histology (P < .0001). In the univariate analysis, initial SUV was associated with OS (Cox model, P = .016; log-rank test, P = .002). In the multivariate analysis, initial SUV dichotomized by the median value (P = .024) and tumor grade (P = .016) proved to be independent OS prognosticators. Median initial SUV for clinical CR patients was 10.2, compared with 15.3 for less than clinical CR patients (P = .0058). The data indicate that a higher initial SUV is associated with poorer OS in patients with esophageal or gastroesophageal carcinoma receiving definitive chemoradiation. Upon validation, baseline PET may become a useful stratification factor in randomized trials and for individualizing therapy.

Value of the primary tumor initial standardized uptake value (iSUV) of 18F-fluorodeoxyglucose positron emission tomography (PET) to predict overall survival (OS) in patients with esophageal or gastroesophageal junction carcinoma undergoing definitive chemoradiotherapy.

82 Background: The value of iSUV of PET for predicting OS is unclear in patients with advanced esophageal or gastroesophageal carcinoma treated with definitive chemoradiotherapy. We tested the hypothesis that iSUV would correlate with OS and recurrence free survival (RFS). Methods: We performed retrospective analysis, selecting patients with esophageal or gastroesophageal carcinoma who had a pretreatment PET and endoscopic ultrasonography (EUS) and who received definitive chemoradiotherapy from 2002 to 2008. Correlations were performed with continuous and dichotomized iSUV, baseline EUS results, OS, and RFS. Results: Two hundred and nine patients were analyzed. The median OS time was 20.7 months (95% CI: 18.8-26.3 months) and the median RFS time was 11.2 months (95% CI: 9.44, 14.34). OS rate and RFS rate at 3 years were 35.7% (95% CI: 29.0-43.9%) and 24.8% (95 % CI: 19.1–32.1 %). The median iSUV was 12.7 (range: 0–51). In univariate analysis, iSUV was associated with OS (Cox model, P = 0.012; log-rank test, P = 0.002) and RFS (Cox model, P = 0.0003; log-rank test, P &lt; 0.0001). In multivariate analysis, dichotomized iSUV cut off by median was associated with OS (P = 0.024) but not RFS (P = 0.11). Conclusions: Data from our study suggests that higher iSUV is associated with poor survival. Baseline PET may become a useful stratification factor in randomized trials and for individualized therapy. No significant financial relationships to disclose.

The role of dual time point FDG PET imaging in the evaluation of solitary pulmonary nodules with an initial standard uptake value less than 2.5

To evaluate the accuracy of dual time point 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET) imaging in the evaluation of the mildly metabolic solitary pulmonary nodule (SPN) and to assess whether accuracy could be improved by delaying second image acquisition to 180 minutes. Fifty-four patients were included in the study. Thirty-six had an SUV(max) <2.5 at 60 min. For these patients, two methods of interpreting the subsequent delayed FDG PET imaging at 180 min were investigated. The first method analysed the SUV(max) of SPNs on delayed imaging, in which an SUV(max) of 2.5 or more was regarded as a criterion for malignancy. The second method was retention index (RI) analysis, in which an increase of 10% or more in SUV(max) between the initial and delayed images, was regarded as an indication of malignancy. For the group as a whole (n=54), the sensitivity, specificity and accuracy of using an SUV(max) of 2.5 or more as an indication of malignancy at the time of initial image acquisition (60 min) was 58, 89, and 74%, respectively. For SPNs that had an initial SUV(max) <2.5 (n=36), the sensitivity, specificity, and accuracy of using an SUV(max) of 2.5 or more as a criterion for malignancy on the delayed image acquisition (180 min), was 36, 96, and 78% respectively. However, if an RI of >10% was used as a criterion for malignancy between the initial and delayed images, the sensitivity, specificity, and accuracy was 73, 80, and 78%, respectively. These results are similar to a recent paper, where image acquisition occurred at 60 and 120 min post-tracer injection. Dual time point FDG PET imaging with RI analysis, is a useful technique in evaluating SPN with an initial SUV(max) <2.5. Prolonging second image acquisition from 120 to 180 min does not appear to improve the accuracy of this technique. However, given that maximal FDG uptake by lung carcinomas is thought to be in the region of 5h, it may be that improving the accuracy of dual time point FDG PET imaging requires a more significant delay in second image acquisition in this specific subgroup.