Metabolic Tumor Burden Predicts for Disease Progression and Death in Lung Cancer

Prognostic significance of preoperative metabolic tumour volume and total lesion glycolysis measured by (18)F-FDG PET/CT in squamous cell carcinoma of the oral cavity

PURPOSE

Metabolic tumour volume (MTV) and total lesion glycolysis (TLG) from (18)F-FDG PET/CT are emerging prognostic biomarkers in human solid cancers; yet few studies have investigated their clinical and prognostic significance in oral cavity squamous cell carcinoma (OSCC). The present retrospective study evaluated the utility of pretreatment MTV and TLG measured by (18)F-FDG PET/CT to predict survival and occult metastasis (OM) in OSCC.

METHODS

Of 162 patients with OSCC evaluated preoperatively by (18)F-FDG PET/CT, 105 who underwent definitive surgery with or without adjuvant therapy were eligible. Maximum standardized uptake value (SUVmax), MTV and TLG were measured. For calculation of MTV, 3-D regions of interest were drawn and a SUV threshold of 2.5 was used for defining regions. Univariate and multivariate analyses identified clinicopathological and imaging variables associated with OM, disease-free survival (DFS) and overall survival (OS).

RESULTS

The median (range) SUVmax, MTV and TLG were 7.3 (0.7-41.9), 4.5 ml (0.7-115.1 ml) and 18.3 g (2.4-224.1 g), respectively. Of 53 patients with clinically negative lymph nodes, OM was detected in 19 (36%). By univariate and multivariate analyses, MTV (P = 0.018) and TLG (P = 0.011) were both independent predictive factors for OM, although they were not independent of each other. The 4-year DFS and OS rates were 53.0% and 62.0%, respectively. Univariate and multivariate analyses revealed that MTV (P = 0.001) and TLG (P = 0.006), with different cut-off levels, were both independent predictive factors for DFS, although they were not independent of each other, and MTV (P = 0.001), TLG (P = 0.002) and the involved resection margin (P = 0.007) were independent predictive factors for OS.

CONCLUSION

Pretreatment MTV and TLG may be useful in stratifying the likelihood of survival and predicting OM in OSCC.

Prediction for recurrence using F-18 FDG PET/CT in pathologic N0 lung adenocarcinoma after curative surgery

BACKGROUND

The aim of this study was to investigate risk factors for recurrence in patients with lung adenocarcinoma (LAD) who were pathologically N0 (pN0) after curative surgical resection.

METHODS

A total of 102 LAD patients (M/F = 55/47, mean age, 62.6 ± 9.4 years) diagnosed as pN0 after curative surgery were included in this study. Clinical, biochemical, radiologic, and pathologic findings were reviewed and analyzed for recurrence. Metabolic parameters [SUVmax, metabolic tumor volume (MTV), total lesion glycolysis (TLG)] on pretreatment F-18 FDG PET/CT were also obtained and analyzed for recurrence.

RESULTS

Of 102 patients, 38 (37.3%) were found to experience recurrence for 33.6 ± 16.3 months. SUVmax, MTV, and TLG were significantly higher in patients with recurrence. The optimal cutoff values determined using a receiver-operating characteristic curve were 6.90 for SUVmax, 10.78 cm(3) for MTV, and 39.68 for TLG. Univariate analysis showed that tumor size, tumor marker, SUVmax, MTV, and TLG were prognostic factors for recurrence. In multivariate analyses, after adjusting for age, sex, tumor size, pathologic T stage, and tumor marker, high SUVmax, MTV, and TLG showed an association with an increased risk of recurrence.

CONCLUSIONS

Metabolic parameters on pretreatment F-18 FDG PET/CT can predict recurrence in pN0 LAD patients who underwent curative surgery. Therefore, patients with high metabolic parameters on PET can be considered as candidates for adjuvant therapy to reduce recurrence and should be monitored carefully for early detection of possible recurrence.

Baseline tumour measurements predict survival in advanced non-small cell lung cancer

BACKGROUND

The association between tumour measurements and survival has been studied extensively in early-stage and locally advanced non-small cell lung cancer (NSCLC). We analysed these factors in patients with advanced NSCLC.

METHODS

Data were derived from the E4599 trial of paclitaxel-carboplatin±bevacizumab. Associations between the Response Evaluation Criteria in Solid Tumors (RECIST) baseline sum longest diameter (BSLD), response rate, progression-free survival (PFS) and overall survival (OS) were evaluated using univariate and multivariable Cox regression models.

RESULTS

A total of 759 of the 850 patients (89%) in the E4599 trial had measurable diseases and were included in this analysis. The median BSLD was 7.5 cm. BSLD predicted OS (hazard ratio (HR) 1.41; P<0.001) and had a trend towards association with PFS (HR 1.14; P=0.08). The median OS was 12.6 months for patients with BSLD <7.5 cm compared with 9.5 months for BSLD ≥ 7.5 cm. This association persisted in a multivariable model controlling multiple prognostic factors, including the presence and sites of extrathoracic disease (HR 1.24; P=0.01). There was no association between BSLD and response rate.

CONCLUSION

Tumour measurements are associated with survival in the E4599 trial. If validated in other populations, this parameter may provide important prognostic information to patients and clinicians.

Prediction of survival by [18F]fluorodeoxyglucose positron emission tomography in patients with locally advanced non-small-cell lung cancer undergoing definitive chemoradiation therapy: results of the ACRIN 6668/RTOG 0235 trial

PURPOSE

In this prospective National Cancer Institute-funded American College of Radiology Imaging Network/Radiation Therapy Oncology Group cooperative group trial, we hypothesized that standardized uptake value (SUV) on post-treatment [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) correlates with survival in stage III non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients received conventional concurrent platinum-based chemoradiotherapy without surgery; postradiotherapy consolidation chemotherapy was allowed. Post-treatment FDG-PET was performed at approximately 14 weeks after radiotherapy. SUVs were analyzed both as peak SUV (SUVpeak) and maximum SUV (SUVmax; both institutional and central review readings), with institutional SUVpeak as the primary end point. Relationships between the continuous and categorical (cutoff) SUVs and survival were analyzed using Cox proportional hazards multivariate models.

RESULTS

Of 250 enrolled patients (226 were evaluable for pretreatment SUV), 173 patients were evaluable for post-treatment SUV analyses. The 2-year survival rate for the entire population was 42.5%. Pretreatment SUVpeak and SUVmax (mean, 10.3 and 13.1, respectively) were not associated with survival. Mean post-treatment SUVpeak and SUVmax were 3.2 and 4.0, respectively. Post-treatment SUVpeak was associated with survival in a continuous variable model (hazard ratio, 1.087; 95% CI, 1.014 to 1.166; P = .020). When analyzed as a prespecified binary value (≤ v > 3.5), there was no association with survival. However, in exploratory analyses, significant results for survival were found using an SUVpeak cutoff of 5.0 (P = .041) or 7.0 (P < .001). All results were similar when SUVmax was used in univariate and multivariate models in place of SUVpeak.

CONCLUSION

Higher post-treatment tumor SUV (SUVpeak or SUVmax) is associated with worse survival in stage III NSCLC, although a clear cutoff value for routine clinical use as a prognostic factor is uncertain at this time.

Prognostic value of preoperative metabolic tumor volume and total lesion glycolysis measured by 18F-FDG PET/CT in salivary gland carcinomas

Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) from (18)F-FDG PET/CT are emerging prognostic biomarkers in various human cancers. This study examined the prognostic value of these metabolic tumor parameters measured by pretreatment (18)F-FDG PET/CT in patients with salivary gland carcinomas.

METHODS

Forty-nine patients with intermediate- or high-grade salivary gland carcinomas who underwent definitive surgery with or without radiotherapy or chemoradiotherapy were evaluated preoperatively by (18)F-FDG PET/CT. Maximum standardized uptake values (SUV max), MTV, and TLG were measured for each patient. Univariate and multivariate analyses were used to identify clinicopathologic and imaging variables associated with progression-free survival (PFS) and overall survival (OS). Univariate analyses included the following variables: age, sex, pT and pN classifications, overall pTNM stage, histologic grade, resection margin, tumor lymphovascular invasion and perineural invasion, postoperative adjuvant therapy, gross total volume, SUV max, MTV, and TLG.

RESULTS

The 3-y PFS and OS rates for all study patients were 66.9% and 81.6%, respectively. The median SUV max, MTV, and TLG were 5.1 (range, 1.7-21.5), 16.2 mL (1.0-115.1 mL), and 24.4 g (2.1-224.4 g), respectively. Univariate analyses showed that there were significant correlations between pT classification, pN classification, MTV, and TLG and both PFS and OS (P < 0.05). However, SUV max was not associated with either PFS (P = 0.111) or OS (P = 0.316). Multivariate analyses revealed that MTV (P = 0.011; hazard ratio, 11.50; 95% confidence interval, 1.45-91.01) and TLG (P = 0.038; hazard ratio, 3.55; 95% confidence interval, 1.07-11.76) were independent variables for PFS.

CONCLUSION

Pretreatment values of MTV and TLG are independent prognostic factors in patients with intermediate or high-grade salivary gland carcinomas.

PET/CT in Oncology: Current Status and Perspectives

The discovery of the Warburg effect in the early twentieth century followed by the development of the fluorinated glucose analogue 18F-fluorodeoxyglucose (18F-FDG) and the invention of positron emission tomographs laid the foundation of clinical PET/CT. This review discusses the challenges and obstacles in clinical adoption of this technique. We then discuss advances in instrumentation, including the critically important introduction of PET/CT and current PET/CT protocols. Moreover, we provide evidence for the clinical utility of PET/CT for patient management and its potential impact on patient outcome, and address its cost and cost-effectiveness. Although this review largely focuses on 18F-FDG imaging, we also discuss a variety of additional molecular imaging approaches that can be used for cancer phenotyping with PET. Throughout this review we emphasize the critical contributions of CT to the strength of PET/CT.

PET-based primary tumor volumetric parameters and survival of patients with non-small cell lung carcinoma

OBJECTIVE

The purpose of the study was to assess metabolic tumor volume and total glycolytic activity of the primary tumor as prognostic parameters for outcome in patients with non-small cell lung carcinoma (NSCLC).

MATERIALS AND METHODS

Thirty-nine patients who had undergone a baseline staging PET/CT examination at our institution for the diagnosis of NSCLC were retrospectively identified. The maximum standardized uptake value (SUV(max)), metabolic tumor volume, and total glycolytic activity were segmented from PET using the gradient method; 12-month survival and overall survival at the end of follow-up were used as outcome measures. Multivariate logistic regression, receiver operating characteristic curve analysis, and Kaplan-Meier curves for survival analysis were generated and compared using the Mantel-Cox log-rank test.

RESULTS

The mean gradient-based metabolic tumor volume and gradient-based total glycolytic activity were significantly greater in the patients who died (93.3 mL and 597.5 g) than in those who survived (19.3 mL and 193.9 g, respectively) (p < 0.003 and p < 0.031). There was no statistically significant difference in the mean SUV(max) between the patients who survived (12.7) at 12 months and those who had died (13.1) (p = 0.85). On multivariate analysis, gradient-based metabolic tumor volume was the only variable associated with 12-month mortality when adjusted for all other factors.(.) The area under the curve (AUC) for gradient-based metabolic tumor volume was 0.77 (p < 0.006). A significant difference in the time to survival was observed between high and low gradient-based metabolic tumor volume (log-rank p < 0.05) cohorts using the median gradient-based metabolic tumor volume (9.7 mL) as the cut point.

CONCLUSION

PET-based volumetric imaging parameters are potential prognostic markers of outcome in patients with NSCLC.

Causes of death of patients with lung cancer

CONTEXT

The causes of death for patients with lung cancer are inadequately described.

OBJECTIVE

To categorize the immediate and contributing causes of death for patients with lung cancer.

DESIGN

The autopsies from 100 patients who died of lung cancer between 1990 and February 2011 were analyzed.

RESULTS

Tumor burden was judged the immediate cause of death in 30 cases, including 26 cases of extensive metastases and 4 cases with wholly or primarily lung tumor burden (causing respiratory failure). Infection was the immediate cause of death for 20 patients, including 8 with sepsis and 12 with pneumonia. Complications of metastatic disease were the immediate causes of death in 18 cases, including 6 cases of hemopericardium from pericardial metastases, 3 from myocardial metastases, 3 from liver metastases, and 3 from brain metastases. Other immediate causes of death were pulmonary hemorrhage (12 cases), pulmonary embolism (10 cases, 2 tumor emboli), and pulmonary diffuse alveolar damage (7 cases). From a functional (pathophysiologic) perspective, respiratory failure could be regarded as the immediate cause of death (or mechanism of death) in 38 cases, usually because of a combination of lung conditions, including emphysema, airway obstruction, pneumonia, hemorrhage, embolism, resection, and lung injury in addition to the tumor. For 94 of the 100 patients, there were contributing causes of death, with an average of 2.5 contributing causes and up to 6 contributing causes of death.

CONCLUSIONS

The numerous and complex ways lung cancer kills patients pose a challenge for efforts to extend and improve their lives.

Prognostic implications of volume-based measurements on FDG PET/CT in stage III non-small-cell lung cancer after induction chemotherapy

PURPOSE

We sought to determine whether metabolic volume-based measurements on FDG PET/CT scans could provide additional information for predicting outcome in patients with stage III non-small-cell lung cancer (NSCLC) treated with induction chemotherapy.

METHODS

Included in the study were 32 patients with stage III NSCLC who were treated with induction platinum-based chemotherapy followed in 21 by surgery. All patients had an FDG PET/CT scan before and after the induction chemotherapy. Tumours were delineated using adaptive threshold methods. The SUVmax, SUVpeak, SUVmean, tumour volume (TV), total lesion glycolysis (TLG), and volume and largest diameter on the CT images (CTV and CTD, respectively) were calculated. Index ratios of the primary tumour were calculated by dividing the follow-up measurements by the baseline measurements. The prognostic value of each parameter for event-free survival (EFS) was determined using Cox regression models.

RESULTS

The median follow-up time was 19 months (range 6-43 months). Baseline PET and CT parameters were not significant prognostic factors. After induction therapy, only SUVmax, SUVpeak, SUVmean, TV, TLG and CTV were prognostic factors for EFS, in contrast to CTD. Of the index ratios, only TV and TLG ratios were prognostic factors for EFS. Patients with a TLG ratio <0.48 had a longer EFS than those with a TLG ratio >0.48 (13.9 vs. 9.2 months, p = 0.04). After adjustment for the effect of surgical treatment, all the parameters significantly correlated with EFS remained significant.

CONCLUSION

SUV, metabolic volume-based indices, and CTV after induction chemotherapy give independent prognostic information in stage III NSCLC. However, changes in metabolic TV and TLG under induction treatment provide more accurate prognostic information than SUV alone, and CTD and CTV.

Feasibility of perfusion CT technique integrated into conventional 18FDG/PET-CT studies in lung cancer patients: clinical staging and functional information in a single study

PURPOSE

To assess the additional functional vascular information and the relationship between perfusion measurements and glucose metabolism (SUVmax) obtained by including a perfusion CT study in a whole-body contrast-enhanced PET/CT protocol in primary lung cancer lesions.

METHODS

Enrolled in this prospective study were 34 consecutive patients with a biopsy-proven diagnosis of lung cancer who were referred for contrast-enhanced PET/CT staging. This prospective study was approved by our institutional review board, and informed consent was obtained from all patients. Perfusion CT was performed with the following parameters: 80 kV, 200 mAs, 30 scans during intravenous injection of 50 ml contrast agent, flow rate 5 ml/s. Another bolus of contrast medium (3.5 ml/s, 80 ml, 60-s delay) was administered to ensure a full diagnostic contrast-enhanced CT scan for clinical staging. The perfusion CT data were used to calculate a range of tumour vascularity parameters (blood flow, blood volume and mean transit time), and tumour FDG uptake (SUVmax) was used as a metabolic indicator. Quantitative and functional parameters were compared and in relation to location, histology and tumour size. The nonparametric Kruskal-Wallis rank sum test was used for statistical analysis.

RESULTS

A cut-off value of 3 cm was used according to the TNM classification to discriminate between T1 and T2 tumours (i.e. T1b vs. T2a). There were significant perfusion differences (lower blood volumes and higher mean transit time) between tumours with diameter >30 mm and tumours with diameter <30 mm (p < 0.05; blood volume 5.6 vs. 7.1 ml/100 g, mean transit time 8.6 vs. 3.9 s, respectively). Also there was a trend for blood flow to be lower in larger lesions (p < 0.053; blood flow 153.1 vs. 98.3 ml/100 g tissue/min). Significant inverse correlations (linear regression) were found between blood volume and SUVmax in tumours with diameter >30 mm in diameter.

CONCLUSION

Perfusion CT combined with PET/CT is feasible technique that may provide additional functional information about vascularity and tumour aggressiveness as a result of lower perfusion and higher metabolism shown by larger lesions.

Prognostic value of metabolic tumor burden from (18)F-FDG PET in surgical patients with non-small-cell lung cancer

OBJECTIVE

To assess the prognostic value of metabolic tumor burden as measured with metabolic tumor volume (MTV) and total lesion glycolysis (TLG) on 2-deoxy-2-((18)F)fluoro-D-glucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT), independent of current Union Internacional Contra la Cancrum/American Joint Committee on Cancer tumor, node, and metastasis (TNM) stage; in comparison with that of standardized uptake value (SUV) in surgical patients with non-small-cell lung cancer (NSCLC).

MATERIAL AND METHODS

This study retrospectively reviewed 104 consecutive surgical patients (47 males, 57 females, median age at PET/CT scan of 67.92 years) with diagnosed stage I to IV NSCLC who had baseline (18)F-FDG PET/CT scans. The (18)F-FDG PET/CT scans were performed in accordance with National Cancer Institute guidelines. The MTV of tumors in the whole body (MTV(WB)), TLG of tumors in the whole body (TLG(WB)), the maximum standardized uptake value of tumors in the whole body (SUV(maxWB)) as well as the mean standardized uptake value of tumor in the whole body (SUV(meanWB)) were measured. The median follow-up among 67 survivors was 42.07 months from the PET/CT (range 2.82-80.95 months). Statistical methods included Kaplan-Meier curves, Cox regression, and C-statistics. The interobserver variability of SUV(maxWB), SUV(meanWB), MTV(WB), and TLG(WB) between two observers was analyzed using concordance correlation coefficients (CCCs).

RESULTS

The interobserver variability of SUV(maxWB), SUV(meanWB), MTV(WB) and TLG(WB) was very low with CCCs greater than 0.882. There was a statistically significant association of stage with overall survival (OS). The hazard ratio (HR) of stage III and stage IV as compared with stage I was 3.60 (P = .001) and 4.00 (P = .013), respectively. The MTV(WB) was significantly associated with OS with a HR for 1-unit increase of ln(MTV(WB)) of 1.40/1.32 (P = .004/.039), before/after adjusting for stage and other prognostic factors including chemoradiation therapy, and surgical procedure, respectively. TLG(WB) had a statistically significant association with OS before and after adjusting for stage and the other prognostic factors. The HR for 1-unit increase in ln(TLG(WB)) was 1.26 (P = .011) and 1.25 (P = .031), before and after the adjustment, respectively. Subjects with conditions that led to pneumonectomy (HR = 2.82, P = .035) or segmental resection (HR = 3.44, P = .044) had significantly worse survival than those needing lobectomy. There was no statistically significant association between OS and age, gender, tumor histology, ln(SUV(maxWB)), and ln(SUV(meanWB)) (all P > .05). There were 37 deaths during follow-up.

CONCLUSION

Baseline whole-body metabolic tumor burden as measured with MTV(WB) and TLG(WB) on FDG PET is a prognostic measure independent of clinical stage and other prognostic factors including chemoradiation therapy and surgical procedure with low interobserver variability and may be used to further risk stratify surgical patients with NSCLC. This study also suggests that MTV and TLG are better prognostic measures than SUV(max) and SUV(mean). These results will need to be validated in larger cohorts in a prospective study.

Prognostic significance of volume-based PET parameters in cancer patients

Accurate prediction of cancer prognosis before the start of treatment is important since these predictions often affect the choice of treatment. Prognosis is usually based on anatomical staging and other clinical factors. However, the conventional system is not sufficient to accurately and reliably determine prognosis. Metabolic parameters measured by ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) have the potential to provide valuable information regarding prognosis and treatment response evaluation in cancer patients. Among these parameters, volume-based PET parameters such as metabolic tumor volume and total lesion glycolysis are especially promising. However, the measurement of these parameters is significantly affected by the imaging methodology and specific image characteristics, and a standard method for these parameters has not been established. This review introduces volume-based PET parameters as potential prognostic indicators, and highlights methodological considerations for measurement, potential implications, and prospects for further studies.

Metabolic tumor volume predicts disease progression and survival in patients with squamous cell carcinoma of the anal canal

PET imaging has become a useful diagnostic tool in patients with anal cancer. We evaluated the prognostic value of metabolic tumor volume (MTV) in patients with anal cancer treated with definitive chemoradiotherapy.

METHODS

Patients with anal cancer who underwent PET imaging for pretreatment staging or radiation therapy planning from 2003 to 2011 were included. PET parameters included MTV and maximum standardized uptake value (SUVmax). Total MTV (MTV-T) was defined as the sum of the volumes above a standardized uptake value 50% of the SUVmax within the primary tumor and involved nodes. Kaplan-Meier and Cox regression models were used to test for associations between metabolic or clinical endpoints and overall survival (OS), progression-free survival (PFS), and event-free survival (EFS).

RESULTS

Thirty-nine patients were included. Median follow-up for the cohort was 22 mo. Overall, 6 patients died and 9 patients had disease progression. The 2-y OS, PFS, and EFS for the entire cohort were 88%, 74%, and 69%, respectively. Higher MTV-T was associated with worse OS (P = 0.04), PFS (P = 0.004), and EFS (P = 0.002) on univariate analysis. Patients with an MTV greater than 26 cm(3) had worse PFS than did those with an MTV of 26 cm(3) or less (33% vs. 82%, P = 0.003). SUVmax was not prognostic for any outcome. Higher T classification (T3/T4 vs. T1/T2) was associated with worse PFS and EFS. When adjusting for T classification, MTV-T remained a significant predictor for PFS (P = 0.01) and EFS (P = 0.02).

CONCLUSION

MTV-T yields prognostic information on PFS and EFS beyond that of established prognostic factors in patients with anal cancer.

Predictive and prognostic value of metabolic tumour volume and total lesion glycolysis in solid tumours

Data available in patients suffering from squamous cell carcinoma of the head and neck, lung carcinoma, oesophageal carcinoma and gynaecological malignancies suggest that metabolic tumour volume and to a lesser extent total lesion glycolysis have the potential to become valuable in the imaging of human solid tumours as prognostic biomarkers for short- to intermediate-term survival outcomes, adding value to clinical staging, for assessment of response to treatment with neoadjuvant and concurrent chemotherapy, and for treatment optimization; for example, based on early treatment response assessment using changes in metabolic tumour volume over time, it might be possible to select patients who require a more aggressive treatment to improve their outcome. Prospective studies enrolling consecutive patients, adopting standardized protocols for FDG PET acquisition and processing, adjusting for potential confounders in the analysis (tumour size and origin) and determining the optimal methodology for determination of these novel markers are mandatory.

Metabolic tumor volume assessed by 18F-FDG PET/CT for the prediction of outcome in patients with multiple myeloma

(18)F-FDG PET/CT allows the direct measurement of metabolic tumor burden in a variety of different malignancies. The aim of this study was to assess whether metabolic tumor volume (MTV) determined by (18)F-FDG PET/CT could be used in the prediction of progression-free and overall survival in multiple myeloma patients.

METHODS

Forty-seven patients (18 women, 29 men; mean age ± SD, 63 ± 11 y) with stage IIIA disease who had undergone whole-body (18)F-FDG PET/CT were retrospectively evaluated. Images underwent a 3-dimensional region-of-interest analysis including all focal lesions with a maximum standardized uptake value > 2.5. The MTV of each lesion was calculated using an automated contouring program based on the standardized uptake value and developed with a threshold of 40% of the maximum standardized uptake value. The total MTV of each patient was defined as the sum of metabolic volume of all focal lesions. Patients were treated and then subjected to a mean follow-up period of 24 mo.

RESULTS

In the 47 patients studied, MTV range was 1.3-316.3 mL, with a median of 23.7 mL. A direct, significant correlation was found between MTV and the percentage of diffuse infiltration of bone marrow by plasma cells (r = 0.46, P = 0.006), whereas hemoglobin levels were inversely correlated with MTV (r = -0.56, P = 0.0001). At follow-up, patients who developed progressive disease (n = 18) showed a significantly higher MTV (74.7 ± 19.3 vs. 29.8 ± 5.1 mL, P = 0.009) than patients without progressive disease (n = 29). Furthermore, patients who died of myeloma (n = 9) had a significantly higher MTV (123.2 ± 30.6 vs. 28.9 ± 4.2 mL, P = 0.0001) than survivors (n = 38). No differences in age, plasma cell infiltration, M protein, albumin, β2-microglobulin, performance status, International Staging System score, and presence or absence of a bone marrow transplant were found between groups. The MTV cutoff level was determined by receiver-operating-characteristic curve analysis, and the best discriminative value found for predicting progression-free and overall survival was 42.2 and 77.6 mL, respectively. By Kaplan-Meier analysis and log-rank testing, progression-free and overall survival at follow-up were significantly better in patients showing an MTV lower than the cutoff than in those having an MTV higher than the cutoff (χ(2) = 3.9, P = 0.04, and χ(2) = 56.3, P < 0.0001, respectively).

CONCLUSION

The direct measurement of tumor burden obtained by calculating MTV on (18)F-FDG PET/CT images may be used in the prediction of progression-free and overall survival in myeloma patients.

Prognostic value of volume-based (18)F-fluorodeoxyglucose PET/CT parameters in patients with clinically node-negative oral tongue squamous cell carcinoma

Objective

To evaluate the prognostic value of volume-based metabolic parameters measured with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) in patients with clinically node-negative (cN0) oral tongue squamous cell carcinoma (OTSCC) as compared with other prognostic factors.

Materials and Methods

In this study, we included a total of 57 patients who had been diagnosed with cN0 tongue cancer by radiologic, ¹⁸F-FDG PET/CT, and physical examinations. The maximum standardized uptake value (SUV_max), average SUV (SUV_avg), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for primary tumors were measured with ¹⁸F-FDG PET. The prognostic significances of these parameters and other clinical variables were assessed by Cox proportional hazards regression analysis.

Results

In the univariate analysis, pathological node (pN) stage, American Joint Committee on Cancer (AJCC) stage, SUV_max, SUV_avg, MTV, and TLG were significant predictors for survival. On a multivariate analysis, pN stage (hazard ratio = 10.555, p = 0.049), AJCC stage (hazard ratio = 13.220, p = 0.045), and MTV (hazard ratio = 2.698, p = 0.033) were significant prognostic factors in cN0 OTSCC patients. The patients with MTV ≥ 7.78 cm³ showed a worse prognosis than those with MTV < 7.78 cm³ (p = 0.037).

Conclusion

The MTV of primary tumor as a volumetric parameter of ¹⁸F-FDG PET, in addition to pN stage and AJCC stage, is an independent prognostic factor for survival in cN0 OTSCC.

Oesophageal squamous cell carcinoma: relationship between fluorine-18 fludeoxyglucose positron emission tomography CT maximum standardised uptake value, metabolic tumour volume, and tumour, node and metastasis classification

OBJECTIVES

We aimed to evaluate the relationships between primary tumour, maximum standardised uptake value, metabolic tumour volume and seventh edition American Joint Committee on Cancer (AJCC) classification in oesophageal squamous cell carcinoma (OSCC) patients.

METHODS

Fluorine-18 fludeoxyglucose ((18)F-FDG) positron emission tomography (PET)-CT scans of 41 consecutive newly diagnosed OSCC patients were retrospectively reviewed. Maximum standard uptake value (SUV(max)) and metabolic tumour volume (MTV) were recorded. Two-tailed Spearman's correlation was used to analyse the relationships between the metabolic parameters and the AJCC staging system.

RESULTS

Positive correlations were observed between SUV(max), MTV and tumour (T) stage, in addition to node (N) stage and AJCC stage. Both metabolic parameters were independent variables that significantly affected the N stage and AJCC stage, and SUV(max) was the only independent variable that significantly affected the T stage.

CONCLUSION

The metabolic parameters derived from (18)F-FDG PET-CT were positively correlated with T, N and AJCC stage in primary OSCC. Our findings may suggest a complementary role of these parameters to seventh-edition AJCC staging in the prognostication of OSCC patients.

Metabolic imaging metrics correlate with survival in early stage lung cancer treated with stereotactic ablative radiotherapy

BACKGROUND AND PURPOSE

To test whether (18)F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) imaging metrics correlate with outcomes in patients with stage I non-small cell lung cancer (NSCLC) treated with stereotactic ablative radiotherapy (SABR).

MATERIAL AND METHODS

Fifty-four patients with stage I NSCLC underwent pre-SABR PET at simulation and/or post-SABR PET within 6 months. We analyzed maximum standardized uptake value (SUV(max)) and metabolic tumor volume defined using several thresholds (MTV50%, or MTV2, 4, 7, and 10). Endpoints included primary tumor control (PTC), progression-free survival (PFS), overall survival (OS) and cancer-specific survival (CSS). We performed Kaplan-Meier, competing risk, and Cox proportional hazards survival analyses.

RESULTS

Patients received 25-60 Gy in 1 to 5 fractions. Median follow-up time was 13.2 months. The 1-year estimated PTC, PFS, OS and CSS were 100, 83, 87 and 94%, respectively. Pre-treatment SUV(max) (p=0.014), MTV(7) (p=0.0077), and MTV(10) (p=0.0039) correlated significantly with OS. In the low-MTV(7)vs. high-MTV(7) sub-groups, 1-year estimated OS was 100 vs. 78% (p=0.0077) and CSS was 100 vs. 88% (p=0.082).

CONCLUSIONS

In this hypothesis-generating study we identified multiple pre-treatment PET-CT metrics as potential predictors of OS and CSS in patients with NSCLC treated with SABR. These could aid risk-stratification and treatment individualization if validated prospectively.

Prognostic value of volumetric parameters measured by F-18 FDG PET/CT in surgically resected non-small-cell lung cancer

OBJECTIVES

The aim of this study was to evaluate the usefulness of the tumor burden as characterized by the metabolic tumor volume (MTV) and total lesion glycolysis (TLG) measured by F-18 fluoro-2-deoxyglucose (F-18 FDG) PET-computed tomography (CT) in predicting recurrence-free survival (RFS) and overall survival (OS) in surgically resected non-small-cell lung cancer (NSCLC) patients.

METHODS

We retrospectively reviewed 91 patients with pathologically documented stages I-IIIA NSCLC. MTV and TLG were obtained according to various thresholds of the standard uptake value (SUV) of primary tumor using preoperative F-18 FDG PET-CT. We used comparison receiver-operating characteristic curve analysis to test the statistical significance of the differences among the multiple volumetric parameters calculated by various SUV cutoff values. RFS and OS were evaluated with the Kaplan-Meier method and Cox regression analysis.

RESULTS

On comparison receiver-operating characteristic curve analysis, no significant difference was found among the volumetric parameters calculated using various thresholds of SUV. Regardless of the thresholds, patients with smaller MTV and lower TLG showed longer RFS and OS. MTV and TLG measured by F-18 FDG PET-CT were found to have better predictive performance than SUVmax for recurrence and death. According to multivariate analyses, MTV2.5 was revealed as a significant prognostic factor for RFS. Tumor size over 3 cm was selected as a significant prognostic indicator of OS.

CONCLUSION

Volume-based parameters of F-18 FDG PET-CT may have a role in providing prognostic information in NSCLC patients who have received surgical treatment.

Prognostic ability of 18F-FDG PET/CT in the assessment of colorectal liver metastases

Modern multidisciplinary therapy for colorectal liver metastases (CRLM) is associated with significant morbidity and must be adapted to the patient's relative risk. The tools currently available to risk-stratify patients are limited. This study assessed the prognostic utility of metabolic measurements derived from(18)F-FDG PET compared with previously proposed prognostic scoring systems.

METHODS

Preoperative (18)F-FDG PET/CT studies from a series of 30 patients who underwent liver resection for CRLM after neoadjuvant chemotherapy were evaluated. Quantitative (18)F-FDG PET analysis calculated the maximum and mean standardized uptake value, metabolic tumor volume (MTV), and tumor glycolytic volume (TGV) as measures of the metabolic activity of tumors. The predictive value of these parameters was compared with that of 4 prognostic scores developed by Fong, Iwatsuki, Nordlinger, and Rees.

RESULTS

High MTV and TGV in patients before metastasectomy were significantly associated with poorer overall survival (MTV: P = 0.001; TGV: P = 0.004) and recurrence-free survival (MTV: P = 0.001, TGV; P = 0.002). Maximum and mean standardized uptake value did not show any significant predictive ability. Of the prognostic scores, prediction of outcome was most accurate using the Basingstoke index (area under the curve, 0.898).

CONCLUSION

Assessment of metabolic tumor burden with volumetric (18)F-FDG PET parameters appears to be a valuable adjunct in determining the biology of CRLM before surgical resection and may enable better risk stratification of patients.

¹⁸F-FDG PET-CT during chemo-radiotherapy in patients with non-small cell lung cancer: the early metabolic response correlates with the delivered radiation dose

Background

To evaluate the metabolic changes on ¹⁸ F-fluoro-2-deoxyglucose positron emission tomography integrated with computed tomography (¹⁸ F-FDG PET-CT) performed before, during and after concurrent chemo-radiotherapy in patients with locally advanced non-small cell lung cancer (NSCLC); to correlate the metabolic response with the delivered radiation dose and with the clinical outcome.

Methods

Twenty-five NSCLC patients candidates for concurrent chemo-radiotherapy underwent ¹⁸ F-FDG PET-CT before treatment (pre-RT PET-CT), during the third week (during-RT PET-CT) of chemo-radiotherapy, and 4 weeks from the end of chemo-radiotherapy (post-RT PET-CT). The parameters evaluated were: the maximum standardized uptake value (SUVmax) of the primary tumor, the SUVmax of the lymph nodes, and the Metabolic Tumor Volume (MTV).

Results

SUVmax of the tumor and MTV significantly (p=0.0001, p=0.002, respectively) decreased earlier during the third week of chemo-radiotherapy, with a further reduction 4 weeks from the end of treatment (p<0.0000, p<0.0002, respectively). SUVmax of lymph nodes showed a trend towards a reduction during chemo-radiotherapy (p=0.06) and decreased significantly (p=0.0006) at the end of treatment. There was a significant correlation (r=0.53, p=0.001) between SUVmax of the tumor measured at during-RT PET-CT and the total dose of radiotherapy reached at the moment of the scan. Disease progression free survival was significantly (p=0.01) longer in patients with complete metabolic response measured at post-RT PET-CT.

Conclusions

In patients with locally advanced NSCLC, ¹⁸ F-FDG PET-CT performed during and after treatment allows early metabolic modifications to be detected, and for this SUVmax is the more sensitive parameter. Further studies are needed to investigate the correlation between the metabolic modifications during therapy and the clinical outcome in order to optimize the therapeutic strategy. Since the metabolic activity during chemo-radiotherapy correlates with the cumulative dose of fractionated radiotherapy delivered at the moment of the scan, special attention should be paid to methodological aspects, such as the radiation dose reached at the time of PET.

Prognostic value of whole-body total lesion glycolysis at pretreatment FDG PET/CT in non-small cell lung cancer

PURPOSE

To determine whether whole-body total lesion glycolysis (TLG), which combines volumetric and metabolic information from fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT), can provide a better evaluation of the prognosis for non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

The institutional review board approved this retrospective study, and the requirement to obtain informed consent was waived. The authors identified 105 consecutive patients with NSCLC who underwent staging FDG PET/CT before any therapy. These patients were free of brain metastasis and underwent standard treatment and subsequent clinical follow-up. Metabolic tumor volume (MTV), mean standardized uptake value (SUV), and maximum SUV of each tumor over the whole body were determined. Whole-body MTV and whole-body TLG are the summation of all the MTVs and summation of individual tumor volume multiplied by its mean SUV, respectively. Univariate and multivariate analyses were performed to assess the prognostic significance of whole-body TLG and other factors, including whole-body MTV, lung TLG, lung MTV, maximum SUV, sex, age, performance status, histologic subtype, T stage, N stage, clinical stage, and treatment method.

RESULTS

The median follow-up time was 3.1 years. The estimated median progression-free survival (PFS) and overall survival (OS) for the cohort was 10.8 months and 2.8 years, respectively. The 1-year PFS was 0.0% for patients with high whole-body TLG (>655) and 50.0% for those with low whole-body TLG (≤655). The 1-year OS was 58.8% for patients with high whole-body TLG and 84.1% for those with low whole-body TLG. Univariate analysis showed that whole-body TLG, whole-body MTV, lung TLG, lung MTV, maximum SUV, performance status, T stage, N stage, clinical stage, and treatment type (surgery vs other) were significant prognostic factors for PFS (P < .01 for all). With use of the forward stepwise multivariate Cox proportional hazards model, whole-body TLG (hazard ratio = 2.92; 95% confidence interval: 1.62, 5.26; P < .01) and surgical treatment (hazard ratio = 4.24; 95% confidence interval: 2.54, 7.07; P < .01) remained significant in PFS.

CONCLUSION

Whole-body TLG is of prognostic value for NSCLC. It may be a promising tool for stratifying patients with NSCLC for risk-adapted therapies.

Prognostic value of tumor burden measurement using the number of tumors in non-surgical patients with non-small cell lung cancer

BACKGROUND

No study to test the feasibility and prognostic value of the number of primary tumors, the number of positive lymph nodes, and the total number of tumors in the whole body as tumor burden measurements on FDG PET/CT imaging has been reported.

PURPOSE

To determine whether the number of tumors seen in 18F-FDG PET scans can be a prognostic factor in non-surgical patients with non-small cell lung cancer (NSCLC).

MATERIAL AND METHODS

One hundred and forty patients with histologically proven NSCLC and baseline 18F-FDG PET scan before therapy were identified in this retrospective analysis. The total number of tumors (TTn) in the whole body, the number of primary tumors (Tn), positive lymph nodes (Nn), and distant metastases (Mn), along with the maximum standardized uptake values (SUV(max)) of the tumors were measured. Inter-observer variability of the total number of tumors, counted by two radiologists, was assessed. Survival analyses were performed to determine the prognostic value of the number of tumors.

RESULTS

Concordance correlation coefficients for the TTn, Tn, Nn, and Mn were all greater than 0.85. TTn and Nn were strong prognostic factors of NSCLC patients' overall survival (OS). In univariate Cox regression models, gender, stage, TTn, Nn, and Mn were statistically significant factors (P = 0.016, 0.032, <0.001, <0.001, and 0.006, respectively). In multivariate Cox regression models, TTn and Nn remained as statistically significant predictors for survival with hazard ratios (HR) of 1.06 (P = 0.001) and 1.11 (P = 0.002), respectively, after adjusting for clinical stage based 7th edition of TNM staging system, age, gender, and SUV(max). Patients with a TTn ≤4 (cutpoint based on median value) had a median OS of 15.2 months compared with 9.0 months for those with TTn >4.

CONCLUSION

Measuring the number of tumors on FDG PET imaging is easy to perform with minimal inter-observer variability. The total number of tumors and number of nodal metastases, as metabolic tumor burden measurements in 18F-FDG PET/CT, are prognostic markers independent of clinical stage, age, gender, and SUV measurement in non-surgical patients with NSCLC.

Independent prognostic value of whole-body metabolic tumor burden from FDG-PET in non-small cell lung cancer

PURPOSE

To determine whether whole-body metabolic tumor burden, measured as either metabolic tumor volume (MTVWB) or total lesion glycolysis (TLGWB), using FDG-PET/CT is an independent prognostic marker in non-small cell lung cancer (NSCLC).

METHODS

328 patients with histologically proven NSCLC were identified for this retrospective analysis. This study was approved by our Institutional Review Board. All patients underwent baseline (18)F-FDG-PET/CT scan imaging before therapy. The MTVWB, TLGWB, maximum standardized uptake value (SUVmaxWB) and mean standardized uptake value (SUVmeanWB) of tumors throughout the whole body were measured from FDG-PET images with semi-automated 3D contouring software.

RESULTS

In univariate analysis, there was a statistically significant association of overall survival (OS) with the MTVWB (hazard ratio (HR) = 1.62, p < 0.001), TLGWB (HR = 1.47, p < 0.001). The patients with a MTVWB ≤ median of 65.7 ml and TLGWB ≤ median of 205.11 SUVmean * ml had a median OS of 41.1 and 35.4 months compared with 9.5 and 9.7 months for those with a MTVWB > 65.7 ml and TLGWB > 205.11 SUVmean * ml, respectively. From a series of multivariate Cox regression models, the MTVWB and TLGWB were significantly better than SUVmaxWB and SUVmeanWB at prognostication and significantly associated with patients' OS with HRs of 1.50 (p < 0.001) and 1.42 (p < 0.001), respectively, after adjustment for patient's age, gender and treatment intent as well as the tumor SUVmaxWB, histology and stage.

CONCLUSIONS

MTVWB and TLGWB as metabolic tumor burden measurements in (18)F-FDG-PET/CT are independent prognostic markers and are significantly better than SUVmaxWB and SUVmeanWB at prognostication.

18F-FDG metabolic tumor volume and total glycolytic activity of oral cavity and oropharyngeal squamous cell cancer: adding value to clinical staging

(18)F-FDG metabolic tumor volume (MTV) and total glycolytic activity (TGA) have been proposed as potential prognostic imaging markers for patient outcome in human solid tumors. The purpose of this study was to establish whether MTV and TGA add prognostic information to clinical staging in patients with oral and oropharyngeal squamous cell carcinomas (SCCs).

METHODS

The Institutional Review Board approved this Health Insurance Portability and Accountability Act-compliant single-institution retrospective study. Forty-five patients with histologically proven oral or oropharyngeal SCC underwent PET/CT for initial cancer staging and were included in the study. MTV was measured using a gradient-based method (PET Edge) and fixed-threshold methods at 38%, 50%, and 60% of maximum standardized uptake value (SUV). The TGA is defined as MTV × mean SUV. Bland-Altman analysis was used to establish the reliability of the methods of segmentation. Outcome endpoints were overall survival (OS) and progression-free survival. Cox proportional hazards univariate and multivariate regression analyses were performed.

RESULTS

In Cox regression models, MTV and TGA were the only factors significantly associated with survival outcome after adjusting for all other covariates including American Joint Committee on Cancer (AJCC) stage, with hazards ratio of 1.06 (95% confidence interval, 1.01-1.10; P = 0.006) and 1.00 (95% confidence interval, 1.00-1.01; P = 0.02). The model fit was significantly better when MTV was added to AJCC stage in model I (χ(2) value change, 1.16-6.71; P = 0.01) and when TGA was added to AJCC stage in model II (χ(2) value change, 1.16-4.37; P = 0.04). The median cutoff point of 7.7 mL for primary tumor MTV was predictive of time to OS (log rank P = 0.04). The median cutoff point of 55 g for PET Edge primary tumor TGA was predictive of time to OS (log rank P = 0.08), though the result was not statistically significant.

CONCLUSION

Gradient-based segmentations of primary tumor MTV and TGA are potential (18)F-FDG markers for time to survival in patients with oral and oropharyngeal SCC and may provide prognostic information in addition to AJCC stage. These exploratory imaging markers need validation in larger cohort studies.

Prognostic value of 18F-FDG PET/CT in patients with squamous cell carcinoma of the tonsil: comparisons of volume-based metabolic parameters

BACKGROUND

The prognostic significance of volume-based metabolic parameters measured by (18)F-fluorodeoxyglucose positron emission tomography/CT ((18) F-FDG PET/CT) is not established. We evaluated the prognostic value of metabolic parameters in patients with squamous cell carcinoma (SCC) of the tonsil.

METHODS

We enrolled a total of 69 patients with SCC of the tonsil who underwent pretreatment (18)F-FDG PET/CT. We measured maximum standardized uptake value (SUV(max)), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and asymmetry indices (of SUV(max), MTV, and TLG). The prognostic significance of these parameters and clinical variables was assessed by Cox proportional hazards regression analysis.

RESULTS

Multivariate analyses with adjustments for age, sex, and American Joint Committee on Cancer stage showed that only TLG (hazard ratio = 1.020, 95% confidence interval 1.003-1.037, p = .023) was an independent predictive factor associated with decreased overall survival.

CONCLUSION

TLG is a significant independent metabolic prognostic factor for overall survival in patients with SCC of the tonsil.

Radiation therapy for liver metastases

Liver metastases are a common source of cancer morbidity and mortality and are often the only site of metastases. In the last 2 decades, major technological advancements in radiation treatment planning and delivery have resulted in resurgence in the use of radiation therapy (RT) as a treatment for liver tumors. With the advent of 3-dimensional conformal radiation treatment (CRT), partial liver irradiation became possible. Stereotactic body radiation therapy (SBRT) is a further enhancement, defined as highly focused, stereotactically localized and administered, high-dose RT delivered in a hypofractionated course. There is now more than a decade of experience with CRT and SBRT for the treatment of liver metastases. In selected patients, very high local control rates have been observed, with minimal toxicity. Patients most likely to benefit from RT are those with liver confined disease, focal distribution of metastases, and metastases more than 1.5 cm from luminal gastrointestinal organs. There is growing evidence that strategies using aggressive or ablative local therapies as an adjunct to systemic therapy might achieve improvements in overall outcome as long as they are administered safely.

Prognostic value of metabolic tumor volume and velocity in predicting head-and-neck cancer outcomes

PURPOSE

We previously showed that metabolic tumor volume (MTV) on positron emission tomography-computed tomography (PET-CT) predicts for disease recurrence and death in head-and-neck cancer (HNC). We hypothesized that increases in MTV over time would correlate with tumor growth and biology, and would predict outcome. We sought to examine tumor growth over time in serial pretreatment PET-CT scans.

METHODS AND MATERIALS

From 2006 to 2009, 51 patients had two PET-CT scans before receiving HNC treatment. MTV was defined as the tumor volume ≥ 50% of maximum SUV (SUV(max)). MTV was calculated for the primary tumor, nodal disease, and composite (primary tumor + nodes). MTV and SUV velocity were defined as the change in MTV or SUV(max) over time, respectively. Cox regression analyses were used to examine correlations between SUV, MTV velocity, and outcome (disease progression and overall survival).

RESULTS

The median follow-up time was 17.5 months. The median time between PET-CT scans was 3 weeks. Unexpectedly, 51% of cases demonstrated a decrease in SUV(max) (average, -0.1 cc/week) and MTV (average, -0.3 cc/week) over time. Despite the variability in MTV, primary tumor MTV velocity predicted disease progression (hazard ratio 2.94; p = 0.01) and overall survival (hazard ratio 1.85; p = 0.03).

CONCLUSIONS

Primary tumor MTV velocity appears to be a better prognostic indicator of disease progression and survival in comparison to nodal MTV velocity. However, substantial variability was found in PET-CT biomarkers between serial scans. Caution should be used when PET-CT biomarkers are integrated into clinical protocols for HNC.

Interim-treatment quantitative PET parameters predict progression and death among patients with Hodgkin's disease

PURPOSE

We hypothesized that quantitative PET parameters may have predictive value beyond that of traditional clinical factors such as the International Prognostic Score (IPS) among Hodgkin's disease (HD) patients.

METHODS

Thirty HD patients treated at presentation or relapse had staging and interim-treatment PET-CT scans. The majority of patients (53%) had stage III-IV disease and 67% had IPS ≥ 2. Interim-treatment scans were performed at a median of 55 days from the staging PET-CT. Chemotherapy regimens used: Stanford V (67%), ABVD (17%), VAMP (10%), or BEACOPP (7%). Hypermetabolic tumor regions were segmented semiautomatically and the metabolic tumor volume (MTV), mean standardized uptake value (SUV mean), maximum SUV (SUV max) and integrated SUV (iSUV) were recorded. We analyzed whether IPS, absolute value PET parameters or the calculated ratio of interim- to pre-treatment PET parameters were associated with progression free survival (PFS) or overall survival (OS).

RESULTS

Median follow-up of the study group was 50 months. Six of the 30 patients progressed clinically. Absolute value PET parameters from pre-treatment scans were not significant. Absolute value SUV max from interim-treatment scans was associated with OS as determined by univariate analysis (p < 0.01). All four calculated PET parameters (interim/pre-treatment values) were associated with OS: MTV int/pre (p < 0.01), SUV mean int/pre (p < 0.05), SUV max int/pre (p = 0.01), and iSUV int/pre (p < 0.01). Absolute value SUV max from interim-treatment scans was associated with PFS (p = 0.01). Three calculated PET parameters (int/pre-treatment values) were associated with PFS: MTV int/pre (p = 0.01), SUV max int/pre (p = 0.02) and iSUV int/pre (p = 0.01). IPS was associated with PFS (p < 0.05) and OS (p < 0.01).

CONCLUSIONS

Calculated PET metrics may provide predictive information beyond that of traditional clinical factors and may identify patients at high risk of treatment failure early for treatment intensification.

Prognostic value of the quantitative metabolic volumetric measurement on 18F-FDG PET/CT in Stage IV nonsurgical small-cell lung cancer

RATIONALE AND OBJECTIVES

Stage IV non-small-cell lung cancer (NSCLC) consists of a heterogeneous group of patients with different prognoses. We assessed the prognostic value of baseline whole body tumor burden as measured by metabolic tumor volume (MTV), total lesion glycolysis (TLG), and standardized uptake values (SUV(max) and SUV(mean)) of all tumors in nonsurgical patients with Stage IV NSCLC.

MATERIALS AND METHODS

Ninety-two consecutive patients with newly diagnosed Stage IV NSCLC who had a pretreatment F-18 fludeoxyglucose positron emission tomography/computed tomography scan were retrospectively reviewed. The MTV, TLG, SUV(mean), and SUV(max) of whole-body (WB) tumors were measured with the MIMvista workstation with manual adjustment.

RESULTS

There was a statistically significant association between overall survival (OS) and ln(MTV)/ln(TLG) at the level of WB tumor burden (MTV(WB)) and of primary tumor (MTV(T)). The hazard ratio (HR) for a 1-unit increase of ln(MTV(WB)) and ln(MTV(T)) before and after adjusting for age and gender was 1.48/1.48 (both P < .001) and 1.25/1.25 (P = .006, .007), respectively. The HR for a 1-unit increase of ln(TLG(WB)) and ln(TLG(T)) before and after adjusting for age and gender was 1.37/1.37 (both P = .001) and 1.19/1.19 (P = .001, .017), respectively. There was no statistically significant association between OS and ln(SUV(max)) and ln(SUV(mean)) at WB tumor burden, primary tumor, nodal metastasis, or distant metastasis (P > .05). There was low interobserver variability between two radiologists with concordance correlation coefficients of 0.90 for ln(MTV(WB)) and greater than 0.90 for SUV(maxWB), SUV(meanWB), and ln(TLG(WB)).

CONCLUSION

Baseline WB metabolic tumor burden, as measured with MTV and TLG, is a prognostic measurement in patients within Stage IV NSCLC with low interobserver variability. This study also suggests pretreatment MTV and TLG measurements may be used to further stratify patients with Stage IV NSCLC and are better prognostic measures than SUV(max) and SUV(mean) measurements.

FDG-PET/CT as prognostic factor and surveillance tool for postoperative radiation recurrence in locally advanced head and neck cancer

Purpose

To evaluate the prognostic value of metabolic tumor volume (MTV) and maximum standardized uptake value (SUVmax) on initial positron emission tomography-computed tomography (PET-CT) and investigate the clinical value of SUVmax for early detection of locoregional recurrent disease after postoperative radiotherapy in patients with locally advanced head and neck squamous cell carcinoma (HNSCC).

Materials and Methods

A total of 100 patients with locally advanced HNSCC received primary tumor excision and neck dissection followed by adjuvant radiotherapy with or without chemotherapy. The MTV and SUVmax were measured from primary sites and neck nodes. The prognostic value of MTV and SUVmax were assessed using initial staging PET/CT (study A). Follow-up PET/CT scan available after postoperative concurrent chemoradiotherapy or radiotherapy were evaluated for the SUVmax value and correlated with locoregional recurrence (study B). A receiver operating characteristic (ROC) curve analysis was used to define a threshold value of SUVmax with the highest accuracy for recurrent disease assessment.

Results

High MTV (>41 mL) is negative prognostic factor for disease free survival (p = 0.041). Postradiation SUVmax was significantly correlated with locoregional recurrence (hazard ratio, 1.812; 95% confidence interval, 1.361 to 2.413; p < 0.001). A cut-off value of 5.38 from follow-up PET/CT was identified as having maximal accuracy for detecting locoregional recurrence by ROC analysis.

Conclusion

MTV at staging work-up was significantly associated with disease free survival. The SUVmax value from follow-up PET/CT showed high diagnostic accuracy for the detection of locoregional recurrence in postoperatively irradiated HNSCC.

Oligometastases treated with stereotactic body radiotherapy: long-term follow-up of prospective study

PURPOSE

To analyze the long-term survival and tumor control outcomes after stereotactic body radiotherapy (SBRT) for metastases limited in number and extent.

METHODS AND MATERIALS

We prospectively analyzed the long-term overall survival (OS) and cancer control outcomes of 121 patients with five or fewer clinically detectable metastases, from any primary site, metastatic to one to three organ sites, and treated with SBRT. Freedom from widespread distant metastasis (FFDM) was defined as metastatic disease not amenable to local therapy (i.e., resection or SBRT). Prognostic variables were assessed using log-rank and Cox regression analyses.

RESULTS

For breast cancer patients, the median follow-up was 4.5 years (7.1 years for 16 of 39 patients alive at the last follow-up visit). The 2-year OS, FFDM, and local control (LC) rate was 74%, 52%, and 87%, respectively. The 6-year OS, FFDM, and LC rate was 47%, 36%, and 87%, respectively. From the multivariate analyses, the variables of bone metastases (p = .057) and one vs. more than one metastasis (p = .055) were associated with a fourfold and threefold reduced hazard of death, respectively. None of the 17 bone lesions from breast cancer recurred after SBRT vs. 10 of 68 lesions from other organs that recurred (p = .095). For patients with nonbreast cancers, the median follow-up was 1.7 years (7.3 years for 7 of 82 patients alive at the last follow-up visit). The 2-year OS, FFDM, and LC rate was 39%, 28%, and 74%, respectively. The 6-year OS, FFDM, and LC rate was 9%, 13%, and 65%, respectively. For nonbreast cancers, a greater SBRT target volume was significantly adverse for OS (p = .012) and lesion LC (p < .0001). Patients whose metastatic lesions, before SBRT, demonstrated radiographic progression after systemic therapy experienced significantly worse OS compared with patients with stable or regressing disease.

CONCLUSIONS

Select patients with limited metastases treated with SBRT are long-term survivors. Future research should address the therapeutic benefit of SBRT for these patients.

Tumor volume as a potential imaging-based risk-stratification factor in trimodality therapy for locally advanced non-small cell lung cancer

INTRODUCTION

The role of trimodality therapy for locally advanced non-small cell lung cancer (NSCLC) continues to be defined. We hypothesized that imaging parameters on pre- and postradiation positron emission tomography (PET)-computed tomography (CT) imaging are prognostic for outcome after preoperative chemoradiotherapy (CRT)/resection/consolidation chemotherapy and could help risk-stratify patients in clinical trials.

METHODS

We enrolled 13 patients on a prospective clinical trial of trimodality therapy for resectable locally advanced NSCLC. PET-CT was acquired for radiation planning and after 45 Gy. Gross tumor volume (GTV) and standardized uptake value were measured at pre- and post-CRT time points and correlated with nodal pathologic complete response, loco-regional and/or distant progression, and overall survival. In addition, we evaluated the performance of automatic deformable image registration (ADIR) software for volumetric response assessment.

RESULTS

All patients responded with average total GTV reductions after 45 Gy of 43% (range: 27-64%). Pre- and post-CRT GTVs were highly correlated (R² = 0.9), and their respective median values divided the patients into the same two groups. ADIR measurements agreed closely with manually segmented post-CRT GTVs. Patients with GTV ≥ median (137 ml pre-CRT and 67 ml post-CRT) had 3-year progression-free survival (PFS) of 14% versus 75% for GTV less than median, a significant difference (p = 0.049). Pre- and post-CRT PET-standardized uptake value did not correlate significantly with pathologic complete response, PFS, or overall survival.

CONCLUSIONS

Preoperative CRT with carboplatin/docetaxel/45 Gy resulted in excellent response rates. In this exploratory analysis, pre- and post-CRT GTV predicted PFS in trimodality therapy, consistent with our earlier studies in a broader cohort of NSCLC. ADIR seems robust enough for volumetric response assessment in clinical trials.

Measurement of tumor volume by PET to evaluate prognosis in patients with advanced non-small cell lung cancer treated by non-surgical therapy

BACKGROUND

Patients with advanced non-small cell lung cancer (NSCLC) seem to have disparity in prognosis. Accurate prediction of prognosis could be useful in the future to predict individual risk and to develop more aggressive or alternative treatment strategies.

PURPOSE

To evaluate the prognostic value of metabolic tumor volume (MTV) measured by 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in patients with NSCLC.

MATERIAL AND METHODS

We retrospectively reviewed 120 patients with pathologically proven NSCLC (61 squamous cell carcinomas and 59 adenocarcinomas) who underwent pretreatment 18F-FDG PET. MTV and maximum standardized uptake value (SUVmax) for the primary tumors were measured by 18F-FDG PET. Pretreatment variables (age, sex, American Joint Committee on Cancer [AJCC] stage, histological type, SUVmax, and MTV) were analyzed to identify their correlation with two-year survival. To further evaluate and compare the predictive value of PET parameters, MTV, and SUVmax, time-dependent receiver-operating characteristic curve (ROC) analysis was used.

RESULTS

In the univariate analysis, AJCC stage, histological type, MTV, and SUVmax of primary tumor were significant predictors of survival. On multivariate analysis, independent prognostic factors associated with decreased two-year survival were AJCC stage (hazard ratio [HR] 2.236, P = 0.003), histological type (HR 2.038, P = 0. 004), and MTV (HR 1.016, P = 0.001). SUVmax was not a significant factor (HR 0.96, P = 0.490). On time-dependent ROC analysis, MTV showed good predictive performance for two-year survival consistently better than SUVmax.

CONCLUSION

MTV, a volumetric parameter of 18F-FDG PET, is an important independent prognostic factor for survival and a better predictor of survival than SUVmax for the primary tumor in patients with advanced NSCLC.

Comparison of outcomes in patients with stage III versus limited stage IV non-small cell lung cancer

BACKGROUND

Standard therapy for metastatic non small cell lung cancer (NSCLC) includes palliative systemic chemotherapy and/or radiotherapy. Recent studies of patients with limited metastases treated with curative-intent stereotactic body radiation therapy (SBRT) have shown encouraging survival. We hypothesized that patients treated with SBRT for limited metastases have comparable outcomes with those treated with curative-intent radiation for Stage III NSCLC.

METHODS

We retrospectively reviewed the records of NSCLC patients treated with curative-intent radiotherapy at the University of Rochester from 2000-2008. We identified 3 groups of patients with NSCLC: stage III, stage IV, and recurrent stage IV (initial stage I-II). All stage IV NSCLC patients treated with SBRT had ≤ 8 lesions.

RESULTS

Of 146 patients, 88% had KPS ≥ 80%, 30% had > 5% weight loss, and 95% were smokers. The 5-year OS from date of NSCLC diagnosis for stage III, initial stage IV and recurrent stage IV was 7%, 14%, and 27% respectively. The 5-year OS from date of metastatic diagnosis was significantly (p < 0.00001) superior among those with limited metastases (≤ 8 lesions) versus stage III patients who developed extensive metastases not amenable to SBRT (14% vs. 0%).

CONCLUSION

Stage IV NSCLC is a heterogeneous patient population, with a selected cohort apparently faring better than Stage III patients. Though patients with limited metastases are favorably selected by virtue of more indolent disease and/or less bulky disease burden, perhaps staging these patients differently is appropriate for prognostic and treatment characterization. Aggressive local therapy may be indicated in these patients, though prospective clinical studies are needed.