Repeat 18F-FDG PET for monitoring neoadjuvant chemotherapy in patients with stage III non-small cell lung cancer

Prognostic value of post-induction chemotherapy 18F-FDG PET-CT in stage II/III non-small cell lung cancer before (chemo-) radiation

INTRODUCTION

The purpose of our present study was to assess the prognostic impact of FDG PET-CT after induction chemotherapy for patients with inoperable non-small-cell lung cancer (NSCLC).

MATERIAL AND METHODS

This retrospective study included 50 patients with inoperable stage II/III NSCLC from January 2012 to July 2015. They were treated for curative intent with induction chemotherapy, followed by concomitant chemoradiation therapy or sequential radiation therapy. FDG PET-CT scans were acquired at initial staging (PET1) and after the last cycle of induction therapy (PET2). Five parameters were evaluated on both scans: SUVmax, SUVpeak, SUVmean, TLG, MTV, and their respective deltas. The prognostic value of each parameter for overall survival (OS) and progression-free survival (PFS) was evaluated with Cox proportional-hazards regression models.

RESULTS

Median follow-up was 19 months. PET1 parameters, clinical and histopathological data were not predictive of the outcome. TLG2 and ΔTLG were prognostic factors for OS. TLG2 was the only prognostic factor for PFS. For OS, log-rank test showed that there was a better prognosis for patients with TLG2< 69g (HR = 7.1, 95%CI 2.8-18, p = 0.002) and for patients with ΔTLG< -81% after induction therapy (HR = 3.8, 95%CI 1.5-9.6, p = 0.02). After 2 years, the survival rate was 89% for the patients with low TLG2 vs 52% for the others. We also evaluated a composite parameter considering both MTV2 and ΔSUVmax. Patients with MTV2> 23cc and ΔSUVmax> -55% had significantly shorter OS than the other patients (HR = 5.7, 95%CI 2.1-15.4, p< 0.01).

CONCLUSION

Post-induction FDG PET might be an added value to assess the patients' prognosis in inoperable stage II/III NSCLC. TLG, ΔTLG as well as the association of MTV and ΔSUVmax seemed to be valuable parameters, more accurate than clinical, pathological or pretherapeutic imaging data.

Long term follow-up of neoadjuvant chemotherapy for non-small cell lung cancer (NSCLC) investigating early positron emission tomography (PET) scan as a predictor of outcome

Background

Neoadjuvant chemotherapy is effective in improving survival of resectable NSCLC. Based on findings in the adjuvant and metastatic setting, FDG positron emission tomography (PET) scans may offer early prognostic or predictive value after one cycle of induction chemotherapy.

Methods

In this phase II non-randomized trial, patients with AJCC version 6 stage IB to IIIB operable NSCLC were treated with 3 cycles of cisplatin and pemetrexed neoadjuvant chemotherapy. Patients underwent FDG-PET scanning prior to and 18 to 21 days after the first cycle of chemotherapy. Investigators caring for patients were blinded to results, unless the scans showed evidence of disease progression. FDG-PET response was defined prospectively as a ≥ 20% decrease in the SUV of the primary lesion.

Results

Between October 2005 and February 2010, 25 patients enrolled. Fifty two percent were female, 88% white, and median age was 62 years. Histology was divided into adenocarcinoma 66%, not otherwise specified (NOS) 16%, squamous cell 12%, and large cell 4%. Stage distribution was: 16% IB, 4% IIB, and 79% IIIA. Treatment was well tolerated and only one patient had a grade 4 toxicity. The median follow up was 95 months. The 5 year progression free survival (PFS) and overall survival (OS) for the entire population were 54 and 67%, respectively. Eighteen patients had a baseline FDG-PET scan and a repeat scan at day 18–21 available for comparison. Ten patients (56%) were considered metabolic responders on the day 18–21 FDG-PET scan. Responders had a 5 year PFS and OS of 60 and 70%, respectively, while the percentage for non-responders was 63 and 75% (p = 0.96 and 0.85).

Conclusions

This phase II trial did not demonstrate that a PET scan after one cycle of chemotherapy can predict survival outcomes of patients with NSCLC treated with neoadjuvant chemotherapy.

Trial registration

NCT00227539 registered September 28th, 2005.

Use of 18F-FDG PET/CT to predict short-term outcomes early in the course of chemoradiotherapy in stage III adenocarcinoma of the lung

The purpose of the present prospective study was to evaluate the use of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in the assessment of therapy response and the prediction of short-term outcomes by maximum and mean standardized uptake values (SUVmax and SUVmean, respectively), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) following chemoradiotherapy (CRT) in patients with stage III adenocarcinoma of the lung. The study included a total of 15 patients, all of whom underwent two serial ¹⁸F-FDG PET/CT scans prior to and following 60-Gy radiotherapy with a concurrent cisplatin/pemetrexed combined chemotherapy regimen. SUVmax, SUVmean, MTV and TLG were determined. Short-term outcomes were assessed according to the Response Evaluation Criteria in Solid Tumors (RECIST) and the PET Response Criteria in Solid Tumors (PERCIST). Post-CRT SUVmax, ΔSUVmax, ΔMTV and ΔTLG varied significantly between responders and non-responders (P=0.009, P=0.015, P=0.006 and P=0.004, respectively). The differences in SUVmax, SUVmean, carcinoembryonic antigen, MTV and TLG between the responders and the non-responders at the initial ¹⁸F-FDG PET/CT scans were not statistically significant (P>0.05). The overall response rate was significantly higher (P=0.01) when evaluated using PERCIST compared with evaluation using RECIST. It was concluded that post-CRT SUVmax, ΔSUVmax, ΔMTV and ΔTLG may be used to differentiate the responders from the non-responders following CRT for stage III adenocarcinoma of the lung. This would aid in deciding whether or not to increase dosages or to incorporate a boost treatment without the requirement to suspend therapy.

Changes in Glucose Metabolism during and after Radiotherapy in Non-Small Cell Lung Cancer

Aims and background

Evaluation of the metabolic response to radiotherapy in non-small cell lung cancer patients is commonly performed about three months after the end of radiotherapy. The aim of the present study was to assess with positron emission tomography/computed tomography (PET/CT) and [18F]fluorodeoxyglucose changes in glucose metabolism during and after radiotherapy in non-small cell lung cancer patients.

Methods and study design

In 6 patients, PET/CT scans with [18F]fluorodeoxyglucose were performed before (PET0), during (PET1; at a median of 14 days before the end of radiotherapy) and after the end of radiotherapy (PET2 and PET3, at a median of 28 and 93 days, respectively). The metabolic response was scored according to visual and semiquantitative criteria.

Results

Standardize maximum uptake at PET1 (7.9 ± 4.8), PET2 (5.1 ± 4.1) and PET3 (2.7 ± 3.1) were all significantly (P <0.05; ANOVA repeated measures) lower than at PET0 (16.1 ± 10.1). Standardized maximum uptake at PET1 was significantly higher than at both PET2 and PET3. There were no significant differences in SUVmax between PET2 and PET3. PET3 identified 4 complete and 2 partial metabolic responses, whereas PET1 identified 6 partial metabolic responses. Radiotherapy-induced increased [18F]fluorodeoxyglucose uptake could be visually distinguished from tumor uptake based on PET/CT integration and was less frequent at PET1 (n = 2) than at PET3 (n = 6).

Conclusions

In non-small cell lung cancer, radiotherapy induces a progressive decrease in glucose metabolism that is greater 3 months after the end of treatment but can be detected during the treatment itself. Glucose avid, radiotherapy-induced inflammation is more evident after the end of radiotherapy than during radiotherapy and does not preclude the interpretation of [18F]fluorodeoxyglucose images, particularly when using PET/CT.

PET Scan Contribution in Chest Tumor Management: A Systematic Review for Thoracic Surgeons

Aims and background

In the 90s, the introduction of positron emission tomography (PET) represented a milestone in the staging of thoracic tumors. In the last 10 years, PET scan has been widely adopted in thoracic oncology, showing high accuracy in diagnosis and staging and with promising issues in defining prognosis. The aim of this systematic review was to focus on the results and pitfalls of PET scan use in the modern management of chest tumors.

Methods and study design.

The literature search was performed on May 2010 in PubMed, Embase, and Cochrane according to PRISMA protocol. The search was restricted to publications in English, using in the same string the word “PET” with 9 different chest tumors; results were then filtered by eliminating technical articles, focusing only on papers in which surgery was considered as a potential diagnostic or therapeutic tool. From 6600 papers initially selected, 99 manuscripts were fully analyzed.

Results

Glucose uptake is a metabolic marker useful in the diagnosis and staging of chest tumors. In lung cancer screening, standard uptake value is helpful in defining the risk of malignancy of isolated pulmonary nodules. The addition of PET scan to conventional staging increases detection of nodal and distant metastases in lung cancer, esophageal cancer and malignant mesothelioma. In thymoma, a close relationship between standard uptake value, histology, and Masaoka stage has been advocated. This link between glucose uptake and prognosis suggests that PET translates biological tumor behavior into clinically detectable findings.

Conclusions

PET scan has a crucial role in thoracic oncology due to its impact on diagnosis, staging and prognosis. PET scan expresses the biological behavior of tumors, opening interesting perspectives in chest tumor management and improving detection and stage grouping in lung cancer. It anticipates the diagnosis in long-incubating diseases such as mesothelioma and increases biological knowledge of rare diseases, such as thymoma and other mediastinal tumors.

Comparison of Quantitative Methods on FDG PET/CT for Treatment Response Evaluation of Metastatic Colorectal Cancer

PURPOSE

FDG PET is effective in treatment response evaluation of cancer. However, there is no standard method for quantitative evaluation of FDG PET, particularly regarding cytostatic drugs. We compared various FDG PET quantitative methods in terms of response determination.

METHODS

A total of 39 refractory metastatic colorectal cancer patients who received a multikinase inhibitor treatment were included. Baseline and posttreatment FDG PET/CT scans were performed before and two cycles after treatment. Standardized uptake value (SUV) and total lesion glycolysis (TLG) values using various margin thresholds (30-70 % of maximum SUV with increment 10 %, twice mean SUV of blood pool, SUV 3.0, and SUV 4.0) were measured, with measurement target of the hottest lesion or a maximum of five hottest lesions. Treatment response by the PERCIST criteria was also determined. Predictive values of the PET indexes were evaluated in terms of the treatment response determined by the RECIST 1.1 criteria.

RESULTS

The agreement rate was 38 % between response determined by the PERCIST and the RECIST criteria (κ = 0.381). When patients were classified into disease control group (PR, SD) and non-control group (PD) by the RECIST criteria, percent changes of TLG with various margin thresholds (particularly, 30-50 % of maximum SUV) exhibited significant differences between the two groups, and high diagnostic power for the response by the RECIST criteria. TLG-based criteria, which used a margin threshold of 50 % of maximum SUV, exhibited a high agreement with the RECIST criteria compared with the PERCIST criteria (κ = 0.606).

CONCLUSION

In metastatic colorectal cancer, FDG PET/CT could be effective for treatment response evaluation by using TLG measured by margin thresholds of 30-50 % of maximum SUV. Further studies are warranted regarding the optimal cutoff values for this method.

Evaluation of lung tumor response to therapy: Current and emerging techniques

Lung tumor response to therapy may be evaluated in most instances by morphological criteria such as RECIST 1.1 on computed tomography (CT) or magnetic resonance imaging (MRI). However, those criteria are limited because they are based on tumoral dimensional changes and do not take into account other morphologic criteria such as density evaluation, functional or metabolic changes that may occur following conventional or targeted chemotherapy. New techniques such as dual-energy CT, PET-CT, MRI including diffusion-weighted MRI has to be considered into the new technical armamentarium for tumor response evaluation. Integration of all informations provided by the different imaging modalities has to be integrated and represents probably the future goal of tumor response evaluation. The aim of the present paper is to review the current and emerging imaging criteria used to evaluate the response of therapy in the field of lung cancer.

Standardized Uptake Decrease on [18F]-Fluorodeoxyglucose Positron Emission Tomography After Neoadjuvant Chemotherapy Is a Prognostic Classifier for Long-Term Outcome After Multimodality Treatment: Secondary Analysis of a Randomized Trial for Resectable Stage IIIA/B Non-Small-Cell Lung Cancer

PURPOSE

A confirmatory analysis was performed to determine the prognostic value of metabolic response during induction chemotherapy followed by bimodality/trimodality treatment of patients with operable locally advanced non-small-cell lung cancer.

PATIENTS AND METHODS

Patients with potentially operable stage IIIA(N2) or selected stage IIIB non-small-cell lung cancer received three cycles of cisplatin/paclitaxel (induction chemotherapy) followed by neoadjuvant radiochemotherapy (RCT) to 45 Gy (1.5 Gy twice per day concurrent cisplatin/vinorelbine) within the ESPATUE (Phase III Study of Surgery Versus Definitive Concurrent Chemoradiotherapy Boost in Patients With Resectable Stage IIIA[N2] and Selected IIIB Non-Small-Cell Lung Cancer After Induction Chemotherapy and Concurrent Chemoradiotherapy) trial. Positron emission tomography scans were recommended before (t0) and after (t2) induction chemotherapy. Patients who were eligible for surgery after neoadjuvant RCT were randomly assigned to definitive RCT or surgery. The prognostic value of percentage of maximum standardized uptake value (%SUVmax) remaining in the primary tumor after induction chemotherapy-%SUVremaining = SUVmax(t2)/SUVmax(t0)-was assessed by proportional hazard analysis and receiver operating characteristic analysis.

RESULTS

Overall, 161 patients were randomly assigned (155 from the Essen and Tübingen centers), and 124 of these received positron emission tomography scans at t0 and t2. %SUVremaining as a continuous variable was prognostic for the three end points of overall survival, progression-free survival, and freedom from extracerebral progression in univariable and multivariable analysis (P < .016). The respective hazard ratios per 50% increase in %SUVremaining from multivariable analysis were 2.3 (95% CI, 1.5 to 3.4; P < .001), 1.8 (95% CI, 1.3 to 2.5; P < .001), and 1.8 (95% CI, 1.2 to 2.7; P = .006) for the three end points. %SUVremaining dichotomized at a cut point of maximum sum of sensitivity and specificity from receiver operating characteristic analysis at 36 months was also prognostic. Exploratory analysis revealed that %SUVremaining was likewise prognostic for overall survival in both treatment arms and was more closely associated with extracerebral distant metastases (P = .016) than with isolated locoregional relapses (P = .97).

CONCLUSION

%SUVremaining is a predictor for survival and other end points after multimodality treatment and can serve as a parameter for treatment stratification after induction chemotherapy or for evaluation of adjuvant new systemic treatment options for high-risk patients.

An alternative parameter for early forecasting clinical response in NSCLC patients during radiotherapy: proof of concept study

OBJECTIVE

Positron emission tomography with (18)F fludeoxyglucose integrated with CT ((18)F-FDG PET/CT) is a recommended imaging procedure in the evaluation of non-small-cell lung cancers (NSCLCs). Radiochemotherapy (RCT) is a mainstay for treatment of locally advanced NSCLC, for which overall survival still remains poor. Early evaluation of treatment response may help in decision-making to complete radiotherapy (RT) or to switch to other treatment modalities. The present study aimed to evaluate the performance of new metabolic parameters based on a simplified kinetic analysis on a single time point (SKA-S)-derived mathematical method, as compared with standardized uptake value (SUV) measurement during RT.

METHODS

Four patients treated with RT or RCT for NSCLC were evaluated using (18)F-FDG PET/CT during RT and after treatment completion. Whole-body (18)F-FDG PET/CT was performed followed by four additional list-mode acquisitions centered over the target lesion. Response was evaluated at four times (i.e. PET1-PET4) by calculating standard SUV values and T80%, the time taken to reach 80% of (18)F-FDG metabolized fraction using a SKA-S-derived mathematical method.

RESULTS

Data from SUV and T80% calculations were found to be controversial. T80% was found to be more predictive of clinical outcome.

CONCLUSION

Although results from this pilot study should be further confirmed in a large prospective study, the data suggest that T80% is a promising metabolic biomarker for assessing early response to RT.

ADVANCES IN KNOWLEDGE

In this proof of concept study, we show that T80% defined from a mathematic model taking into account the net influx rate constant and vascular volume could be consider as a promising biomarker as compared with the maximum SUV.

Utility of Routine PET Imaging to Predict Response and Survival After Induction Therapy for Non-Small Cell Lung Cancer

BACKGROUND

Data from clinical trials suggest that changes in the glucose avidity of the primary site of lung cancer during induction therapy, measured by changes in (18)F-fluorodeoxyglucose positron emission tomography, correlate with tumor response. Little information about the utility of changes in positron emission tomography imaging of involved lymph nodes during induction chemotherapy is available. The utility of positron emission tomography imaging of either the primary site or nodal metastases, obtained during routine clinical care outside of a clinical trial setting, to predict response has also not been examined.

METHODS

A retrospective review of all surgical patients with non-small cell lung cancer at a single institution imaged between 2000 and 2006 with (18)F-fluorodeoxyglucose positron emission tomography before or after induction therapy was performed.

RESULTS

An increase in standardized uptake value in the primary site of disease during induction therapy was associated with reduced overall survival after resection. Neither pretreatment standardized uptake value nor percentage change in the primary site was associated with overall survival after resection. A decrease in standardized uptake value of greater than 60% in the involved N2 mediastinal nodes was the best predictor of overall survival, better than changes seen in the primary site of disease.

CONCLUSIONS

An increase in glucose avidity of non-small cell lung cancers during induction therapy was associated with a worse prognosis compared with stable or any decrease in standardized uptake value. Changes in the glucose avidity of mediastinal nodal metastases may be a stronger predictor of survival than changes in the primary site of disease.

Quantitative Imaging in Radiation Oncology: An Emerging Science and Clinical Service

Radiation oncology has long required quantitative imaging approaches for the safe and effective delivery of radiation therapy. The past 10 years has seen a remarkable expansion in the variety of novel imaging signals and analyses that are starting to contribute to the prescription and design of the radiation treatment plan. These include a rapid increase in the use of magnetic resonance imaging, development of contrast-enhanced imaging techniques, integration of fluorinated deoxyglucose-positron emission tomography, evaluation of hypoxia imaging techniques, and numerous others. These are reviewed with an effort to highlight challenges related to quantification and reproducibility. In addition, several of the emerging applications of these imaging approaches are also highlighted. Finally, the growing community of support for establishing quantitative imaging approaches as we move toward clinical evaluation is summarized and the need for a clinical service in support of the clinical science and delivery of care is proposed.

Metabolic response assessment with 18F-FDG PET/CT: inter-method comparison and prognostic significance for patients with non-small cell lung cancer

OBJECTIVE

This study aimed to (1) compare the agreement of two evaluation methods of metabolic response in patients with non-small cell lung cancer (NSCLC) and determine their prognostic value and (2) explore an optimal cutoff of metabolic reduction to distinguish a more favorable subset of responders.

METHODS

This is a secondary analysis of prospective studies. Enrolled patients underwent 18F-PET/CT within 2 weeks before, during, and months after radiotherapy (post-RT). Metabolic response was assessed using both Peter MacCallum (PM) method of qualitative visual assessment and University of Michigan (UM) method of semiquantitative measurement. The agreement between two methods determined response, and their prediction of outcome was analyzed.

RESULTS

Forty-four patients with median follow-up of 25.2 months were analyzed. A moderate agreement was observed between PM- and UM-based response assessment (Kappa coefficient = 0.434), unveiling a significant difference in CMR rate (p = 0.001). Categorical responses derived from either method were significantly predictive of overall survival (OS) and progression-free survival (PFS) (p < 0.0001). Numerical percentage decrease of FDG uptake also showed significant correlations with survival, presenting a hazard ratio of 0.97 for both OS and PFS. A 75 % of SUV decrease was found to be the optimal cutoff to predict OS and 2-year progression.

CONCLUSIONS

There was a modest discrepancy in metabolic response rates between PM and UM criteria, though both could offer predictive classification for survival. The percentage decrease provides an ordinal value that correlates with prolonged survival, recommending 75 % as the optimal threshold at identifying better responders.

PET/CT in therapy evaluation of patients with lung cancer

FDG-PET/CT is a well documented and widespread used imaging modality for the diagnosis and staging of patient with lung cancer. FDG-PET/CT is increasingly used for the assessment of treatment effects during and after chemotherapy. However, PET is not an accepted surrogate end-point for assessment of response rate in clinical trials. The aim of this review is to present current evidence on the use of PET in response evaluation of patients with lung cancer and to introduce the pearls and pitfalls of the PET-technology relating to response assessment. Based on this and relating to validation criteria, including stable technology, standardization, reproducibility and broad availability, the review discusses why, despite numerous studies on response assessment indicating a possible role for FDG-PET/CT, PET still has no place in guidelines relating to response evaluation in lung cancer.

[Clinical use of 18F-FDG PET/CT in colorectal carcinoma]

Modern imaging techniques have an important role in the diagnostic procedures of malignancies, and assessing response to therapy. The 18F-FDG PET/CT revolutionized the evaluation of colorectal cancer in terms of preoperative staging and monitoring of recurrence. Conventional imaging techniques have limitations in early assessment of response to therapy. 18F-FDG PET has been shown to allow earlier treatment monitoring, because the metabolic change appears before any anatomic change occurs. The Response Evaluation Criteria in Solid Tumours (RECIST) are widely applied, but they have some limitations. There are new international guidelines for treatment response assessment using PET/CT in solid tumours. The authors review indications and the role of hybrid PET/CT in colorectal cancer.

18F-FDG-PET evaluation of pathological tumour response to neoadjuvant therapy in patients with NSCLC

OBJECTIVES

The ability to identify potential responders to neoadjuvant treatment may improve patient selection or surgery and may help in the development of response criteria suitable for routine monitoring of response. The aim of this study was to evaluate the value of PET in predicting the pathological tumour response of non-small-cell lung cancer (NSCLC) to neoadjuvant therapy using a meta-analysis.

METHODS

All available published studies investigating the value of PET in predicting the pathological response of NSCLC to neoadjuvant therapy were collected. Pooled sensitivity and specificity data were obtained using statistical software. Subgroup analysis was performed to explore the sources of heterogeneity.

RESULTS

A total of 13 studies comprising 414 patients with NSCLC were included in the meta-analysis. Pooled sensitivity, specificity, positive predictive value and negative predictive value for PET-predicted response was 83% [95% confidence interval (CI); 76-89%], 84% (95% CI; 79-88%), 74% (95% CI; 67-81%) and 91% (95% CI; 87-94%), respectively. Significant heterogeneity (P<0.05) was observed. On the basis of our subgroup analyses, methodological quality could be responsible for this heterogeneity in our metaregression. The predictive value of PET in NSCLC patients with pathological response (considered the gold standard) was significantly higher than that of computed tomography (P<0.05).

CONCLUSION

PET scanning has an important role in predicting nonresponders to neoadjuvant therapy in cases of NSCLC, and the predictive value of PET for evaluating pathologically documented responses is superior to that of computed tomography. However, additional evaluations using prospective clinical trials will be required to assess the clinical benefit of this strategy.

Treatment of stage III non-small cell lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

OBJECTIVES

Stage III non-small cell lung cancer (NSCLC) describes a heterogeneous population with disease presentation ranging from apparently resectable tumors with occult microscopic nodal metastases to unresectable, bulky nodal disease. This review updates the published clinical trials since the last American College of Chest Physicians guidelines to make treatment recommendations for this controversial subset of patients.

METHODS

Systematic searches were conducted through MEDLINE, Embase, and the Cochrane Database for Systematic Review up to December 2011, focusing primarily on randomized trials, selected meta-analyses, practice guidelines, and reviews.

RESULTS

For individuals with stage IIIA or IIIB disease, good performance scores, and minimal weight loss, treatment with combined chemoradiotherapy results in better survival than radiotherapy alone. Consolidation chemotherapy or targeted therapy following definitive chemoradiation for stage IIIA is not supported. Neoadjuvant therapy followed by surgery is neither clearly better nor clearly worse than definitive chemoradiation. Most of the arguments made regarding patient selection for neoadjuvant therapy and surgical resection provide evidence for better prognosis but not for a beneficial impact of this treatment strategy; however, weak comparative data suggest a possible role if only lobectomy is needed in a center with a low perioperative mortality rate. The evidence supports routine platinum-based adjuvant chemotherapy following complete resection of stage IIIA lung cancer encountered unexpectedly at surgery. Postoperative radiotherapy improves local control without improving survival.

CONCLUSIONS

Multimodality therapy is preferable in most subsets of patients with stage III lung cancer. Variability in the patients included in randomized trials limits the ability to combine results across studies and thus limits the strength of recommendations in many scenarios. Future trials are needed to investigate the roles of individualized chemotherapy, surgery in particular cohorts or settings, prophylactic cranial radiation, and adaptive radiation.

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.

Early response to chemotherapy in patients with non-small-cell lung cancer assessed by [18F]-fluoro-deoxy-D-glucose positron emission tomography and computed tomography

BACKGROUND

This study aimed to demonstrate that patients who exhibit a tumor metabolic response to first-line chemotherapy seen on FDG-PET and computed tomography (CT) would survive longer than those who did not show such a response, comparing this evaluation with the morphologic response seen on CT.

PATIENTS AND METHODS

Images were acquired in 22 consecutive patients with advanced non-small-cell lung cancer (NSCLC) randomized to receive carboplatin/paclitaxel/sorafenib or placebo. FDG-PET was performed within 4 weeks before (PET1) and 2 weeks after starting treatment (PET2). Similarly, CT (CT1) was performed at baseline and then every 2 cycles (6 weeks) during treatment (CT2). Responders and nonresponders were identified with FDG-PET, and metabolic response was then compared with morphologic changes detected by spiral CT.

RESULTS

Twenty-one of 22 patients completed this study. In terms of progression-free survival (PFS) (45 vs. 22.2 weeks) and overall survival (OS) (77 vs. 47.7 weeks), we observed a trend that was not statistically significant for patients whose response after 2 weeks of treatment was seen on FDG-PET (P = .22 for PFS; P = .15 for OS).

CONCLUSION

Patients with advanced NSCLC who had a positive outcome, as evidenced by prolonged survival, were those who showed a tumor metabolic response seen on FDG-PET.

Response assessment using 18F-FDG PET early in the course of radiotherapy correlates with survival in advanced-stage non-small cell lung cancer

This study investigated the possibility of early response assessment based on (18)F-FDG uptake during radiotherapy with respect to overall survival in patients with non-small cell lung cancer.

METHODS

(18)F-FDG PET/CT was performed before radiotherapy and was repeated in the second week of radiotherapy for 34 consecutive lung cancer patients. The CT volume and standardized uptake value (SUV) parameters of the primary tumor were quantified at both time points. Changes in volume and SUV parameters correlated with 2-y overall survival.

RESULTS

The average change in mean SUV in the primary tumor of patients with a 2-y survival was a decrease by 20% ± 21%-significantly different (P < 0.007) from nonsurvivors, who had an increase by 2% ± 22%. A sensitivity and specificity of 63% and 93%, respectively, to separate the 2 groups was reached for a decrease in mean SUV of 15%. Survival curves were significantly different using this cutoff (P = 0.001). The hazard ratio for a 1% decrease in mean SUV was 1.032 (95% confidence interval, 1.010-1.055). Changes in tumor volume defined on CT did not correlate with overall survival.

CONCLUSION

The use of repeated (18)F-FDG PET to assess treatment response early during radiotherapy is possible in patients undergoing radiotherapy or sequential or concurrent chemoradiotherapy. A decrease in (18)F-FDG uptake by the primary tumor correlates with higher long-term overall survival.

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.

Baseline SUVmax at PET-CT in stage IIIA non-small-cell lung cancer patients undergoing surgery after neoadjuvant therapy: prognostic implication focused on histopathologic subtypes

RATIONALE AND OBJECTIVES

To evaluate the prognostic significance of maximum standardized uptake value (SUVmax) at (18)F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography in patients with stage IIIA non-small-cell lung cancer (NSCLC) who underwent surgical resection after neoadjuvant chemoradiotherapy, focused on the relationship between SUVmax values and tumor histology.

MATERIALS AND METHODS

We retrospectively evaluated the initial SUVmax of 205 patients (112 adenocarcinomas, 82 squamous cell carcinomas [SCCs], and 11 of other histology) with a stage IIIA NSCLC who underwent surgical resection after neoadjuvant chemoradiotherapy, and who were followed for up to 6 years. Clinical data, including histologic type, pathologic response, and treatment, were reviewed, and the relationship between the SUVmax and patient overall survival was examined.

RESULTS

Overall, the 2-year survival rate was 68%. Between the two histologic subtypes of adenocarcinoma and SCC, we noted significant differences in all variables of gender (male predominance in SCC), initial SUVmax (greater in SCC), pathologic response (more complete remission in SCC), and overall survival (better in SCC) (all P values, < .05). SUVmax remained as a sole independent factor for survival in multivariate analysis in whole series (SUVmax cutoff, 13; median survival, 3.0 years vs. 4.0 years; P = .016) and in adenocarcinomas (SUVmax cutoff, 11.5; median survival, 2.6 years vs. 3.6 years; P = .045), but not in SCCs.

CONCLUSION

The initial SUVmax is a sole significant prognostic factor in patients with a surgically resected NSCLC after neoadjuvant chemoradiotherapy, particularly in patients with an adenocarcinoma.

Lung cancer: Morphological and functional approach to screening, staging and treatment planning

Lung cancer is a major problem in public health and constitutes the leading cause of cancer-related mortality in the world. Lung cancer screening with low-dose computed tomography is promising but needs to overcome many difficulties, such as the large number of incidentally discovered nodules, the radiation dose delivered to the patient during a whole screening program and its cost. The ultimate target point represented by the reduction of lung cancer-related mortality needs to be proved in large, well-designed, randomized, multicenter, prospective trials. Lung cancer staging by morphological tools seems to be limited owing to the presence of metastases in normal-sized lymph nodes. In this context, multidetector computed tomography cannot be used alone but is useful in conjunction with molecular imaging and MRI. Today, flurodeoxglucose PET-CT appears to be the most accurate method for lung cancer staging and may prevent unnecessary thoracotomies. For treatment planning, flurodeoxglucose PET-CT is playing an increasing role in radiotherapy planning at the target selection and definition steps.

Is FDG-PET suitable for evaluating neoadjuvant therapy in non-small cell lung cancer? Evidence with systematic review of the literature

BACKGROUND

Neoadjuvant therapy response assessment is crucial in patients with non-small cell lung cancer (NSCLC). FDG-PET has emerged as a valuable tool for defining therapy response assessment in other tumours.

AIM

To systematically review publications appearing in the literature describing induction therapy response assessment with FDG-PET in NSCLC.

METHODS

We performed a bibliographic search and selected only prospective studies in order to include the highest levels of evidence.

RESULTS

Nine of 497 potentially relevant publications were selected. The ranges of sensitivity, specificity, positive predictive value and negative predictive value for primary tumour response assessment were 80-100%, 0-100%, 42.9-100%, and 66.7-100%, respectively. Pooling data for N2 restaging after neoadjuvant response the overall sensitivity was 63.8% (95% CI, 53.3-73.7%) and overall specificity was 85.3% (95% CI, 80.4-89.4%).

CONCLUSION

The results of the analysis do not support the use of FDG-PET as the only re-assessment tool for mediastinal lymph node evaluation for routine clinical use. FDG-PET seems to predict primary tumour response to induction therapy but it could not be shown by pooling analysis.

Nuclear EGFR as novel therapeutic target: insights into nuclear translocation and function

Emerging evidence suggests the existence of a new mode of epidermal growth factor receptor (EGFR) signaling in which activated EGFR undergoes nuclear translocation following treatment with ionizing radiation. The authors provide evidence that the nuclear EGFR transport is a stress-specific cellular reaction, which is linked to src-dependent EGFR internalization into caveolae. These flask-shaped pits can fuse with endoplasmic reticulum and the EGFR is sorted into a perinuclear localization. This compartment may serve as a reservoir for nuclear EGFR transport which is regulated by PKCepsilon (protein kinase Cepsilon). Nuclear EGFR is able to induce transcription of genes essential for cell proliferation and cell-cycle regulation. Moreover, nuclear EGFR has physical contact with compounds of the DNA repair machinery and is involved in removal of DNA damage. Anti-EGFR strategies target radiation-associated EGFR nuclear translocation in different manners. EGFR-inhibitory antibodies, i.e., cetuximab (Erbitux((R))), can block nuclear translocation by EGFR immobilization within the cytosol in responder cell lines, whereas tyrosine kinase inhibitors rather target nuclear kinase activity of EGFR linked with cytosolic or nuclear functions. However, both strategies can inhibit DNA repair following irradiation.

Early prediction of response to first-line chemotherapy by sequential [18F]-2-fluoro-2-deoxy-D-glucose positron emission tomography in patients with advanced colorectal cancer

BACKGROUND

To evaluate [(18)F]-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET), for early evaluation of response to palliative chemotherapy and for prediction of long-term outcome, in patients with metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

In a randomized trial, patients with mCRC received irinotecan-based combination chemotherapy. FDG-PET was carried out before treatment and after two cycles in 51 patients at two centers. Visual changes in tumor FDG uptake and changes measured semi-automatically, as standard uptake values (SUVs), were compared with radiological response after four and eight cycles.

RESULTS

The mean baseline SUV for all tumor lesions per patient was higher in nonresponders than in responders (mean 7.4 versus 5.6, P = 0.02). There was a strong correlation between metabolic response (changes in SUV) and objective response (r = 0.57, P = 0.00001), with a sensitivity of 77% and a specificity of 76%. There was no significant correlation between metabolic response and time to progression (P = 0.5) or overall survival (P = 0.1).

CONCLUSIONS

Although metabolic response assessed by FDG-PET reflects radiological tumor volume changes, the sensitivity and specificity are too low to support the routine use of PET in mCRC. Furthermore, PET failed to reflect long-term outcome and can, thus, not be used as surrogate end point for hard endpoint benefit.

Respiration-averaged CT for attenuation correction in non-small-cell lung cancer

PURPOSE

Breathing causes artefacts on PET/CT images. Cine CT has been used to reduce respiratory artefacts by acquiring multiple images during a single breathing cycle. The aim of this prospective study in non-small-cell lung cancer (NSCLC) patients was twofold. Firstly, we sought to compare the motion artefacts in PET/CT images attenuation-corrected with helical CT (HCT) and with averaged CT (ACT), which provides an average of cine CT images. Secondly, we wanted to evaluate the differences in maximum standardized uptake values (SUV(max)) between HCT and ACT.

METHODS

Enrolled in the study were 80 patients with NSCLC. PET images attenuation-corrected with HCT (PET/HCT) and with ACT (PET/ACT) were obtained in all patients. Misregistration was evaluated by measurement of the curved photopenic area in the lower thorax of the PET images for all patients and direct measurement of misregistration for selected lesions. SUV(max) was measured separately at the primary tumours, regional lymph nodes, and background.

RESULTS

A total of 80 patients with NSCLC were included. Significantly lower misregistrations were observed in PET/ACT images than in PET/HCT images (below-thoracic misregistration 0.25+/-0.58 cm vs. 1.17+/-1.17 cm, p<0.001; lesion misregistration 1.38+/-2.10 vs. 3.10+/-4.09, p=0.013). Significantly higher SUV(max) were noted in PET/ACT images than in PET/HCT images in the primary tumour (p<0.001) and regional lymph nodes (p<0.001). Compared with PET/HCT images, the magnitude of SUV(max) in PET/ACT images was higher by 0.35 for the main tumours and 0.34 for lymph nodes.

CONCLUSION

Due to its significantly reduced misregistration, PET/ACT provided more reliable SUV(max) and may be useful in treatment planning and monitoring the therapeutic response in patients with NSCLC.

Computed Tomography Response, But Not Positron Emission Tomography Scan Response, Predicts Survival After Neoadjuvant Chemotherapy for Resectable Non–Small-Cell Lung Cancer

Purpose

Tumor response is considered a surrogate marker of survival. We investigated whether tumor response based on computed tomography (CT) scan or whole-body [18F]fluorodeoxyglucose positron emission tomography (PET) scan after neoadjuvant chemotherapy for resectable non–small-cell lung cancer (NSCLC) is prognostic of survival.

Patients and Methods

Two consecutive phase II clinical trials were jointly analyzed. Patients underwent CT and PET scans before and after completion of neoadjuvant chemotherapy, followed by surgery.

Results

Eighty-nine patients were included. Patients with a partial or complete response based on Response Evaluation Criteria in Solid Tumors categories (n = 33) had a better overall survival than those with stable or progressive disease (n = 56; median survival time, not reached v 36 months, respectively; P = .04). Of all patients, those with response in the highest quartile had 1- and 2-year survival rates of 100% and 81%, respectively, compared with 77% and 61%, respectively, among patients in the lowest quartile. However, on the basis of visual analysis of PET scan, patients with a metabolic response (n = 28) had no significant difference in survival compared with patients without response (n = 61; median survival time, 35.6 months v not reached, respectively; P = .94). In addition, on the basis of a semiquantitative analysis of PET scan, using at least 30% reduction in tumor metabolism as a response (n = 59), we also found no significant difference in survival among those with or without response.

Conclusion

Among patients with resectable NSCLC treated with neoadjuvant chemotherapy, we found no evidence that tumor response by PET scan after chemotherapy is prognostic of survival; however, response by CT scan was associated with better survival.

Selection of response criteria for clinical trials of sarcoma treatment

Soft tissue sarcomas are a heterogeneous group of malignancies arising from mesenchymal tissues. A large number of new therapies are being evaluated in patients with sarcomas, and consensus criteria defining treatment responses are essential for comparison of results from studies completed by different research groups. The 1979 World Health Organization (WHO) handbook set forth operationally defined criteria for response evaluation in solid tumors that were updated in 2000 with the publication of the Response Evaluation Criteria in Solid Tumors (RECIST). There have been significant advances in tumor imaging, however, that are not reflected in the RECIST. For example, computed tomography (CT) slice thickness has been reduced from 10 mm to < or =2.5 mm, allowing for more reproducible and accurate measurement of smaller lesions. Combination of imaging techniques, such as positron emission tomography with fluorine-18-fluorodeoxyglucose (18FDG-PET) and CT can provide investigators and clinicians with both anatomical and functional information regarding tumors, and there is now a large body of evidence demonstrating the effectiveness of PET/CT and other newer imaging methods for the detection and staging of tumors as well as early determination of responses to therapy. The application of newer imaging methods has the potential to decrease both the sample sizes required for, and duration of, clinical trials by providing an early indication of therapeutic response that is well correlated with clinical outcomes, such as time to tumor progression or overall survival. The results summarized in this review support the conclusion that the RECIST and the WHO criteria for evaluation of response in solid tumors need to be modernized. In addition, there is a current need for prospective trials to compare new response criteria with established endpoints and to validate imaging-based response rates as surrogate endpoints for clinical trials of new agents for sarcoma and other solid tumors.

Prognostic stratification of stage IIIA-N2 non-small-cell lung cancer after induction chemotherapy: a model based on the combination of morphometric-pathologic response in mediastinal nodes and primary tumor response on serial 18-fluoro-2-deoxy-glucose positron emission tomography

PURPOSE

Surgical resection in patients with stage IIIA-N2 non-small-cell lung cancer (NSCLC) is usually reserved for patients with mediastinal downstaging after induction chemotherapy (IC). However, clinical restaging is often inaccurate, and there are insufficient data to conclude that all patients with persistent mediastinal disease will not benefit from surgery, or that all patients with mediastinal clearance benefit from surgery. We created a data-based restaging strategy combining morphometric tissue analysis of mediastinal lymph nodes (LNs) and 18-fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) response monitoring in the primary tumor.

PATIENTS AND METHODS

Baseline and repeat FDG-PET after IC, as well as complete resection specimens of both mediastinal LNs and primary tumor, were available in 30 patients. Histologic response grading was performed by means of conventional morphometric procedures. Mediastinal response grading combined with the percentage decrease of maximum standardized uptake value (SUV(max)) on the primary tumor was correlated with survival.

RESULTS

Patients with persistent major mediastinal LN involvement have a 5-year overall survival rate of 0%. The 5-year overall survival rate for patients with cleared or persistent minor mediastinal LN involvement was significantly higher in patients with a more than 60% decrease in SUV(max) on the primary tumor as compared with patients with a less than 60% decrease in SUV(max) (62% v 13%; log-rank P = .002).

CONCLUSION

These data may suggest that (1) persistent mediastinal disease after IC does not always exclude favorable outcome after surgery; (2) serial FDG-PET may select surgical candidates among patients with mediastinal downstaging or persistent minor disease; (3) persistent major mediastinal disease has a poor prognosis and such patients should not be considered for surgery.

Long-Term Survival Associated With Complete Resection After Induction Chemotherapy in Stage IIIA (N2) and IIIB (T4N0-1) Non–Small-Cell Lung Cancer Patients: The Spanish Lung Cancer Group Trial 9901

Purpose

To assess the activity of induction chemotherapy followed by surgery in stage IIIA and selected stage IIIB non–small-cell lung cancer patients.

Patients and Methods

Mediastinoscopy proof of either positive N2 (IIIA) or T4N0-1 (IIIB) disease was required. Induction therapy was three cycles of cisplatin/gemcitabine/docetaxel, followed by surgery.

Results

From December 1999 to March 2003, 136 patients were entered onto the study; the clinical response rate in 129 assessable patients was 56%. The overall complete resection rate was 68.9% of patients eligible for surgery (72% of stage IIIA patients and 66% of stage IIIB patients) and 48% of all assessable patients. Eight (12.9%) of 62 completely resected patients had a pathologic complete response. Seven patients (7.8%) died during the postoperative period. The median overall survival time was 15.9 months, 3-year survival rate was 36.8%, and 5-year survival rate was 21.1%, with no significant differences in survival between stage IIIA and stage IIIB patients. Median survival time was 48.5 months for 62 completely resected patients, 12.9 months for 13 incompletely resected patients, and 16.8 months for 15 nonresected patients (P = .005). Three- and 5-year survival rates were 60.1% and 41.4% for completely resected patients, 23.1% and 11.5% for incompletely resected patients, and 31.1% and 0% for nonresected patients, respectively. In the multivariate analysis, complete resection (hazard ratio [HR] = 0.35; P < .0001), clinical response (HR = 0.32; P < .0001), and age younger than 60 years (HR = 0.64; P = .027) were the most powerful prognostic factors.

Conclusion

Induction chemotherapy followed by surgery is effective in stage IIIA and in selected stage IIIB patients attaining complete resection.

PET/CT in oncology: for which tumours is it the reference standard?

Positron emission tomography (PET)/computed tomography (CT) has a growing role in the imaging of many cancers. As our experience has grown over the past number of years so has our understanding for which cancers it is particularly useful. The value of PET/CT at each stage of the cancer journey is different for each cancer. This review attempts to tease out the role of PET/CT in the common cancers with particular emphasis on where it is the imaging investigation of choice.