Response and progression-free survival in oropharynx squamous cell carcinoma assessed by pretreatment perfusion CT: comparison with tumor volume measurements

Pre-treatment tumour perfusion parameters and initial RECIST response do not predict long-term survival outcomes for patients with head and neck squamous cell carcinoma treated with induction chemotherapy

Objectives

Previously, we showed that pre-treatment tumour plasma perfusion (F_p) predicts RECIST response to induction chemotherapy (ICT) in locoregionally advanced head and neck squamous cell carcinoma (HNSCC). The aim here was to determine whether the pre-treatment tumour F_p estimate, changes in tumour F_p or RECIST response post 2 cycles of ICT were prognostic for long-term survival outcomes.

Methods

A prospective study enrolled patients with high stage HNSCC treated with docetaxel (T), cisplatin (P) and 5-fluorouracil (F) (ICT) followed by synchronous cisplatin and intensity modulated radiotherapy. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) before and after two cycles of ICT was used to measure F_p and RECIST response.

Results

Forty-two patients were recruited and 37 underwent two scans. The median follow-up was 36 (range 23–49) months. Pre-treatment tumour F_p (stratified by median) was not prognostic for overall survival (p = 0.42), disease specific survival (p = 0.20) and locoregional control (p = 0.64). Neither change in tumour F_p nor RECIST response post two cycles of ICT was prognostic for any outcome (p>0.21).

Conclusion

DCE-MRI parameters do not predict long-term survival outcomes following ICT and RECIST response to ICT may not be an appropriate endpoint to determine early efficacy of a treatment in HNSCC patients.

Multiparametric imaging using 18F-FDG PET/CT heterogeneity parameters and functional MRI techniques: prognostic significance in patients with primary advanced oropharyngeal or hypopharyngeal squamous cell carcinoma treated with chemoradiotherapy

Background

In this study, PET heterogeneity was combined with functional MRI techniques to refine the prediction of prognosis in patients with oropharyngeal or hypopharyngeal squamous cell carcinoma (OHSCC).

Methods

A total of 124 patients with primary advanced OHSCC who underwent pretreatment ¹⁸F-FDG PET/CT, dynamic contrast-enhanced MR imaging (DCE-MRI), and diffusion-weighted MR imaging (DWI) were enrolled. Conventional and heterogeneity parameters from ¹⁸F-FDG PET as well as perfusion parameters from DCE-MRI and diffusion parameter from DWI of primary tumors were analyzed in relation to recurrence-free survival (RFS) and overall survival (OS).

Results

Multivariate analysis identified hypopharyngeal tumors (P = 0.038), alcohol drinking (P = 0.006), K^trans ≤ 0.5512 (P = 0.017), and K_ep ≤ 0.8872 (P = 0.005) as adverse prognostic factors for RFS. Smoking (p = 0.009), K^trans ≤ 0.5512 (P = 0.0002), K_ep ≤ 0.8872 (P = 0.004), and the PET heterogeneity parameter uniformity ≤ 0.00381 (P = 0.028) were independent predictors of poor OS. The combination of PET uniformity with DCE-MRI parameters and smoking allowed distinguishing four prognostic groups, with 3-year OS rates of 100%, 76.6%, 57.4%, and 7.1%, respectively (P < 0.0001). This prognostic system appeared superior to both the TNM staging system (P = 0.186) and the combination of conventional PET parameters with DCE-MRI (P = 0.004).

Conclusions

Multiparametric imaging based on PET heterogeneity and DCE-MRI parameters combined with clinical risk factors is superior to the concomitant use of functional MRI coupled with conventional PET parameters. This approach may improve the prognostic stratification of OHSCC patients.

CT-based volumetric tumor growth velocity: A novel imaging prognostic indicator in oropharyngeal cancer patients receiving radiotherapy

OBJECTIVES

Volumetric tumor growth velocity (TGV) reflects in vitro tumor aggressiveness, but its prognostic value has not been investigated in vivo. We examined the prognostic impact of TGV on oncologic outcomes in patients with oropharyngeal squamous cell cancer (OSCC).

MATERIALS AND METHODS

101 OSCC patients with two pretreatment CTs with time gap of 2 or more weeks treated at a single institution between 2004 and 2008 were identified. Primary tumor and nodal targets were segmented in scans. Linear growth rates were calculated. Recursive partitioning analysis (RPA) identified cut point associated with outcomes.

RESULTS

Median follow-up was 59months (range 7-118). Median primary TGV was 0.65% increase per day (range 0-9.37%). RPA identified TGV cut point associated with local control (LC) of 1% per day. Patients with higher TGV had decreased 5-year LC (73% vs. 98%, p=0.0004), distant control (DC, 62% vs. 91%, p=0.0007), and overall survival (OS, 38% versus 93%, p<0.0001). In multivariate analysis including demographics, tumor stage, subsite, and treatment factors, TGV⩾1% per day independently predicted worsened LC (p = 0.02), DC (p = 0.003), and OS (p < 0.0001). However, this TGV cutoff was not significantly predictive of LC, DC, or OS for a subset of presumed HPV-positive patients.

CONCLUSION

OSCC TGV⩾1% per day is a substantive negative prognostic indicator for disease control and overall survival, particularly in HPV non-associated tumors. This novel CT-based volumetric assessment of TGV suggests a simple methodology for risk stratification of patients.

Assessing Tumor Response to Treatment in Patients with Lung Cancer Using Dynamic Contrast-Enhanced CT

The aim of this study was to provide an overview of the literature available on dynamic contrast-enhanced computed tomography (DCE-CT) as a tool to evaluate treatment response in patients with lung cancer. This systematic review was compiled according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only original research articles concerning treatment response in patients with lung cancer assessed with DCE-CT were included. To assess the validity of each study we implemented Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). The initial search yielded 651 publications, and 16 articles were included in this study. The articles were divided into groups of treatment. In studies where patients were treated with systemic chemotherapy with or without anti-angiogenic drugs, four out of the seven studies found a significant decrease in permeability after treatment. Four out of five studies that measured blood flow post anti-angiogenic treatments found that blood flow was significantly decreased. DCE-CT may be a useful tool in assessing treatment response in patients with lung cancer. It seems that particularly permeability and blood flow are important perfusion values for predicting treatment outcome. However, the heterogeneity in scan protocols, scan parameters, and time between scans makes it difficult to compare the included studies.

Dynamic volume perfusion computed tomography parameters versus RECIST for the prediction of outcome in lung cancer patients treated with conventional chemotherapy

INTRODUCTION

To compare dynamic volume perfusion computed tomography (dVPCT) parameters with Response Evaluation Criteria in Solid Tumors (RECIST 1.1) for prediction of therapy response and overall survival (OS) in non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC) patients treated with conventional chemotherapy.

METHODS

A total of 173 lung cancer patients (131 men; 61 ± 10 years) undergoing dVPCT before (T1) and after chemotherapy (T2) and follow-up were prospectively included. dVPCT-derived blood flow, blood volume, mean transit time, and permeability (PERM) were assessed, compared between NSCLC and SCLC and patients' response to therapy was determined according to RECIST 1.1.

RESULTS

One hundred of one hundred and seventy-three patients underwent dVPCT at T1 and T2 within a median of 44 (range, 31-108) days. dVPCT values were differing in NSCLC and SCLC, but were not significantly differing between patients with partial response, stable, or progressive disease. Eighty-five patients (NSCLC = 72 and SCLC = 13) with a follow-up for greater than or equal to 6 months were analyzed for OS. Fifty-six of eighty-five patients died during follow-up. Receiver operating characteristic analysis determined T1/T2 with highest predictive values regarding OS for blood flow, blood volume, mean transit time, and permeability (area under the curve: 0.53, 0.61, 0.54, and 0.53, respectively, all p > 0.05). Kaplan-Meier statistics revealed OS of patient groups assigned according to dVPCT T1/T2 cutoff values was not differing for neither dVPCT parameter, whereas RECIST groups significantly differed in OS (p = 0.02). Cox proportional hazards regression determined progressive disease status to independently predict OS (p = 0.004), while none of the dVPCT parameters did so.

CONCLUSIONS

dVPCT values, differ between NSCLC and SCLC, are not related to RECIST 1.1 classification and do not improve OS prediction in lung cancer patients treated with conventional chemotherapy.

Technical prerequisites and imaging protocols for CT perfusion imaging in oncology

The aim of this review article is to define the technical prerequisites of modern state-of-the-art CT perfusion imaging in oncology at reasonable dose levels. The focus is mainly on abdominal and thoracic tumor imaging, as they pose the largest challenges with respect to attenuation and patient motion. We will show that low kV dynamic scanning in conjunction with detection technology optimized for low photon fluxes has the highest impact on reducing dose independently of other choices made in the protocol selection. We discuss, derived from relatively simple first principles, on what appropriate temporal sampling and total scan duration depend on and why optimized contrast medium injection protocols are also essential in limiting dose. Finally we will examine the possibility of simultaneously extracting standard morphological and functional information from one single 4D examination as a potential enabler for a more widespread use of dynamic contrast enhanced CT in oncology.

Role of CT perfusion in monitoring and prediction of response to therapy of head and neck squamous cell carcinoma

This review aims to summarize the technique and clinical applications of CT perfusion (CTp) of head and neck cancer. The most common pathologic type (90%) of head and neck cancer is squamous cell carcinoma (HNSCC): its diagnostic workup relies on CT and MRI, as they provide an accurate staging for the disease by determining tumour volume, assessing its extension, and detecting of lymph node metastases. Compared with conventional CT and MRI, CTp allows for obtaining measures of tumour vascular physiology and functional behaviour, and it has been demonstrated to be a feasible and useful tool in predicting local outcomes in patients undergoing radiation therapy and chemotherapy and may help monitor both treatments.

Perfusion CT of head and neck cancer

We aim to review the technique and clinical applications of perfusion CT (PCT) of head and neck cancer. The clinical value of PCT in the head and neck includes detection of head and neck squamous cell carcinoma (HNSCC) as it allows differentiation of HNSCC from normal muscles, demarcation of tumor boundaries and tumor local extension, evaluation of metastatic cervical lymph nodes as well as determination of the viable tumor portions as target for imaging-guided biopsy. PCT has been used for prediction of treatment outcome, differentiation between post-therapeutic changes and tumor recurrence as well as monitoring patient after radiotherapy and/or chemotherapy. PCT has a role in cervical lymphoma as it may help in detection of response to chemotherapy and early diagnosis of relapsing tumors.

Predicting tumour response

Response prediction is an important emerging concept in oncologic imaging, with tailored, individualized treatment regimens increasingly becoming the standard of care. This review aims to define tumour response and illustrate the ways in which imaging techniques can demonstrate tumour biological characteristics that provide information on the likely benefit to be received by treatment. Two imaging approaches are described: identification of therapeutic targets and depiction of the treatment-resistant phenotype. The former approach is exemplified by the use of radionuclide imaging to confirm target expression before radionuclide therapy but with angiogenesis imaging and imaging correlates for genetic response predictors also demonstrating potential utility. Techniques to assess the treatment-resistant phenotype include demonstration of hypoperfusion with dynamic contrast-enhanced computed tomography and magnetic resonance imaging (MRI), depiction of necrosis with diffusion-weighted MRI, imaging of hypoxia and tumour adaption to hypoxia, and 99mTc-MIBI imaging of P-glycoprotein mediated drug resistance. To date, introduction of these techniques into clinical practice has often been constrained by inadequate cross-validation of predictive criteria and lack of verification against appropriate response end points such as survival. With further refinement, imaging predictors of response could play an important role in oncology, contributing to individualization of therapy based on the specific tumour phenotype. This ability to predict tumour response will have implications for improving efficacy of treatment, cost-effectiveness and omission of futile therapy.

Multiparametric PET/CT in oncology

The standardized uptake value (SUV) and other measurements of tumour uptake of fluorodeoxyglucose (FDG) on positron emission tomography (PET) can potentially be supplemented by additional imaging parameters derived either from the PET images or from the computed tomography (CT) component of integrated PET/CT examinations including tumour size, CT attenuation, texture (reflecting tumour heterogeneity) and blood flow. This article illustrates the emerging benefits of such a multiparametric approach. Example benefits include greater diagnostic accuracy in characterization of adrenal masses achieved by using both the SUV and measured CT attenuation. Tumour size combined with the SUV can potentially improve the prognostic information available from PET/CT in oesophageal and lung cancer. However, greater improvements may be realized through using CT measurements of texture instead of size. Studies in breast and lung cancer suggest that combined PET/CT measurements of glucose metabolism and blood flow provide correlates for tumour proliferation and angiogenesis, respectively. These combined measurements can be utilized to determine vascular-metabolic phenotypes, which vary with tumour type. Uncoupling of blood flow and metabolism suggests a poor prognosis for larger more advanced tumours, high-grade lesions and tumours responding poorly to treatment. Vascular-metabolic imaging also has the potential to subclassify tumour response to treatment. The additional biomarkers described can be readily incorporated in existing FDG-PET examinations thereby improving the ability of PET/CT to depict tumour biology, characterize potentially malignant lesions, and assess prognosis and therapeutic response.

Dynamic contrast-enhanced MR perfusion imaging of head and neck tumors at 3 Tesla

BACKGROUND

Dynamic contrast-enhanced (DCE) MR perfusion imaging allows assessment of vascular density and integrity of tumors. The purpose of this study was to determine the diagnostic efficacy of time intensity curve analysis on DCE MRI for characterization of head and neck tumors.

METHODS

Twenty patients underwent T1-weighted fast field echo DCE MRI with temporal resolution of 2.6 seconds. In total, 100 dynamic phases covering 20 slices were obtained in 4.5 minutes. Time to peak (TTP), relative maximum enhancement (RME) ratio, and relative washout ratio (RWO) were calculated.

RESULTS

Malignant tumors had a significantly lower RME (p = .025) and prolonged TTP with lower RWO than benign lesions. Postradiation changes had a significantly longer TTP (p = .024) and lower RWO (p = .007) than did postradiation recurrent tumors. Receiver operating characteristic (ROC) analysis revealed RWO had highest accuracy (area under the curve [AUC] = 1.0).

CONCLUSIONS

DCE MR perfusion imaging provides pivotal information regarding microcirculation, potentially improves differentiation of malignant tumor from postradiation changes.

Prediction of locoregional control in head and neck squamous cell carcinoma with serial CT perfusion during radiotherapy

BACKGROUND AND PURPOSE

Tumor hypoxia is a known factor of radioresistance in HNSCC. CTP is a noninvasive method of measuring tumor perfusion in vivo. The purpose of our study was to determine serial changes in tumor perfusion in HNSCC during a course of RT by using CTP and to correlate tumor perfusion measurements to LRC.

MATERIALS AND METHODS

A prospective study was performed in 15 patients with HNSCC receiving definitive RT who underwent serial CTP before RT; at weeks 2, 4, and 6 of RT; and 6 weeks after RT. The median follow-up was 28 months (range, 6-44 months). Thirteen patients achieved LRC, and 2 patients had LRF. Tumor perfusion parameters, including BF, BV, MTT, and CP, were obtained by using a deconvolution-based analysis.

RESULTS

Pretreatment tumor BF was significantly higher in patients who achieved LRC, 118.0 mL/100 g/min, compared with those with LRF, 53.4 mL/100 g/min (P = .004). Similarly, pretreatment CP was higher in patients with LRC, 16.6 mL/100 g/min, compared with those with LRF, 7.7 mL/100 g/min (P = .02). At week 2 of RT, tumor BF parameters showed a 27.5% increase versus an 18.1% decrease from pretreatment BF values (P = .046) in patients with LRC and LRF, respectively. A decrease in BF and BV was observed in both groups 6 weeks after RT compared with these values at baseline scanning.

CONCLUSIONS

An increase in tumor BF and CP by using CTP early during a course of RT predicts LRC in patients with HNSCC treated with RT.

An exploratory pilot study into the association between microcirculatory parameters derived by MRI-based pharmacokinetic analysis and glucose utilization estimated by PET-CT imaging in head and neck cancer

OBJECTIVES

To examine the feasibility of deriving quantitative microcirculatory parameters and to investigate the relationship between vascular and metabolic characteristics of head and neck tumours in vivo, using dynamic contrast-enhanced (DCE) MRI and fluorodeoxyglucose (FDG) PET imaging.

METHODS

Twenty-seven patients with primary squamous cell carcinoma (SCCA) underwent DCE-MRI and combined PET/CT imaging. DCE-MRI data were post-processed by using commercially available software. Transfer constant (K (trans)), extravascular extracellular blood volume (v (e)), transfer constant from the extracellular extravascular space to plasma (k (ep)) and iAUC (initial area under the signal intensity-time curve) were calculated. 3D static PET data were acquired and standardised uptake values (SUV) calculated.

RESULTS

All microcirculatory parameters in tumours were higher than in normal muscle tissue (P ≤ 0.0019). Significant correlations were shown between k (ep) and K (trans) (ρ = 0.77), v (e) and k (ep) (ρ = -0.7), and iAUC and v (e) (ρ = 0.53). Significant correlations were observed for SUV(mean) and v (e) as well as iAUC (ρ = 0.42 and ρ = 0.66, respectively). SUV(max) was significantly correlated with iAUC (ρ = 0.69).

CONCLUSIONS

The demonstrated relationships between vascular and metabolic characteristics of primary SCCA imply a complex interaction between vascular delivery characteristics and tumour metabolism. The lack of correlation between SUV and K (trans)/k (ep) suggests that both diagnostic techniques may provide complementary information.