Pretreatment metabolic tumor volume as a prognostic factor in HPV-associated oropharyngeal cancer in the context of AJCC 8th edition staging

Qualitative and quantitative methods in post-chemoradiation PET for head and neck cancer

OBJECTIVE

The aim of this study was to determine whether quantitative methods could aid in the evaluation of post-treatment head and neck scans, particularly taking human papillomavirus status into account.

METHODS

Clinical readings of positron emission tomography/computed tomography scans as well as standardized uptake value (SUV)max (and other metrics) of nodes visible on PET conducted on a total of 172 patients with head and neck squamous cell cancer were examined. Locoregional recurrence at 2 years was assessed. In total 88 of these patients had close enough follow-up to determine whether individual nodes were positive or negative, and 233 nodes on these patients were compared to surgical pathology notes or follow-up (if no path was available).

RESULTS

General negative predictive value (NPV) of complete response was 93% and an equivocal response was 89%; focusing on nodal recurrence, NPV was found to be 97% and positive predictive value (PPV) 46% if equivocal reads were treated as negative and NPV 98% and PPV 16% if equivocal reads were treated as positive. Using SUVmax of the hottest node with a cutoff of 3.4 gave NPV 97% and PPV 26%; a direct re-read (using 2 observers) gave NPV 98% and PPV 32% if equivocal reads were treated as negative, and NPV 99% and PPV 18% if equivocal reads were treated as positive. Using other first-order radiomics data such as SD and skewness did not improve this.

CONCLUSIONS

Quantitative data such as SUVmax does not show additional value over qualitative evaluation of response to chemoradiation in head and neck tumors.

Imaging response assessment for predicting outcomes after bioselection chemotherapy in larynx cancer: A secondary analysis of two prospective trials

BACKGROUND AND PURPOSE

Bioselection with induction chemotherapy in larynx cancer is associated with excellent larynx preservation and disease-specific survival but requires visual inspection of the primary tumor. We retrospectively compare clinical and imaging response in bioselected patients to develop predictive models of surgeon-assessed response (SR), laryngectomy-free survival (LFS), and overall survival (OS) in bioselected patients.

MATERIALS AND METHODS

In a secondary analysis of patients on two single-institution bioselection trials, model building used a regularized regression model (elastic-net) and applied nested cross-validation. Logistic regression-based model was used to predict SR and Cox proportional hazard-based models were used to predict LFS and OS.

RESULTS

In 115 patients with a median age of 57 years, most patients had supraglottic tumors (73.0%) and T3/T4 disease (94.8%). Definitive treatment was chemoradiation in 76.5% and laryngectomy in 23.5%. Change in primary tumor (OR = 5.78, p < 0.001) and N-classification (OR = 1.64, p = 0.003) predicted SR (AUC 0.847). Change in tumor volume (HR = 0.58, p < 0.001) predicted LFS (c-index 0.724). N-classification (HR = 1.48, p = 0.04) and pre-chemotherapy tumor volume (HR = 1.30, p = 0.174) predicted OS (c-index 0.552).

CONCLUSIONS

Imaging offers a non-invasive opportunity to evaluate response to induction chemotherapy, complementary to surgeon assessment. Further evaluation of approaches to bioselection that optimize generalizability of this paradigm are needed, and clinical trials utilizing imaging to predict outcomes including LFS are warranted.

Tumor Glucose Metabolism and Its Heterogeneity on F-18 FDG PET/CT Provide Better Prognostication in Nonmetastatic Human Papillomavirus-Related Oropharyngeal Squamous Cell Carcinoma

Simple Summary

Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) emerged as a distinct disease with a favorable prognosis, and a separate staging system was introduced. However, a subset of patients harbor a poor prognosis. We aimed to evaluate the prognostic role of metabolic parameters on baseline F-18 FDG PET/CT in patients with HPV-related OPSCC. We retrospectively reviewed patients who were diagnosed with stage I, II, and III HPV-related OPSCC using the 8th TNM staging. Metabolic features on baseline F-18 FDG PET/CT, such as higher tumor glucose metabolism derived from tumor SUV_max to liver SUV_mean ratio, and increased intratumoral heterogeneity inferred from coefficient of variation were associated with poorer progression-free survival and overall survival. Further study is warranted to address the possible implications of F-18 FDG PET/CT on treatment de-intensification in these patients.

Abstract

Background: We aimed to evaluate the prognostic role of metabolic parameters on baseline F-18 fluorodeoxyglucose (FDG) PET/CT in patients with human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC). Methods: We retrospectively reviewed patients who were diagnosed with nonmetastatic HPV-related OPSCC using the 8th TNM staging system from 2010 to 2015 and underwent baseline F-18 FDG PET/CT. Tumor SUV_max to liver SUV_mean ratio (SUV_max-TLR), metabolic tumor volume (MTV), tumor total lesion glycolysis to liver SUV_mean ratio (TLG-TLR), and coefficient of variation (CV) of the primary tumor were measured. Patients were primarily treated with surgery or radiotherapy. Endpoints were progression-free survival (PFS) and overall survival (OS). Results: Ninety consecutive patients (male, 72; female, 18) were enrolled. They were followed up for a median of 77.4 months (interquartile range, 48.4–106.4). Sixteen patients progressed, and 13 died. Multivariate analysis revealed that patients with advanced age, overall stage, and higher SUV_max-TLR or CV had poorer PFS and OS. Conclusion: Higher SUV_max-TLR and CV of the primary tumor on baseline F-18 FDG PET/CT were associated with poorer PFS and OS in patients with nonmetastatic HPV-related OPSCC. Further study is warranted to address the possible implications of F-18 FDG PET/CT on treatment de-intensification in these patients.

Role of 18F-FDG PET-derived parameters for predicting complete response to chemoradiotherapy in squamous cell anal carcinoma

PURPOSE

We aimed to evaluate the accuracy of metabolic parameters, calculated on pretreatment positron emission computed tomography (PET/CT) with fluorodeoxyglucose (F-FDG), for predicting complete response to chemoradiotherapy (CRT) of patients affected by squamous cell anal carcinoma (SCAC).

PATIENTS AND METHODS

Clinical records of 20 patients affected by SCAC and treated with CRT were retrospectively evaluated. F-FDG PET/CT was performed at time 0 (baseline) and time 1 (12 weeks after CRT). The following parameters were extracted from PET at time 0: standardized uptake values (SUVmax and SUVmean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG). Response was assessed according to PET response criteria in solid tumors and classified as complete metabolic response (CMR), partial metabolic response (PMR) and progressive metabolic disease (PMD). Receiver operating characteristic analysis was performed to analyze the predictive value of each PET-derived parameter on CMR.

RESULTS

Sixteen patients were finally enrolled. All presented increased F-FDG uptake in the primary tumor and 11 (68.7%) also showed metastatic lymph nodes. At PET/CT performed at time 1, 11 subjects (68.7%) presented CMR, three (18.7%) had PMR and the remaining two (12.5%) showed PMD (i.e. hepatic metastases). Among baseline PET-derived parameters, both MTV and TLG efficiently predicted response to CRT with an area under the curve of 0.9 (cutoff 62.3 cm, sensitivity 80%, specificity 100%, P = <0.0001) and 0.87 (cutoff 654.1 g, sensitivity 80%, specificity 100%, P = 0.004), respectively.

CONCLUSION

Among PET-derived parameters, both MTV and TLG presented a high predictive value on subjects' outcome after CRT.

Prediction of Response in Head and Neck Tumor: Focus on Main Hot Topics in Research

Radiation therapy is a cornerstone in the treatment of head and neck cancer patients; actually, their management is based on clinical and radiological staging with all patients at the same stage treated in the same way. Recently the increasing knowledge in molecular characterization of head and neck cancer opens the way for a more tailored treatment. Patient outcomes could be improved by a personalized radiotherapy beyond technological and anatomical precision. Several tumor markers are under evaluation to understand their possible prognostic or predictive value. In this paper we discuss those markers specific for evaluate response to radiation therapy in head and neck cancer for a shift toward a biological personalization of radiotherapy.

Predictive Value of Occult Metastasis and Survival Significance of Metabolic Tumor Volume Determined by PET-CT in cT1-2N0 Squamous Cell Carcinoma of the Tongue

Objectives

Our goal was to analyze the possibility of using metabolic tumor volume (MTV) to predict occult cervical metastasis and survival in cT1-2N0 squamous cell carcinoma (SCC) of the tongue.

Methods

Data on the primary tumor MTV and cervical node status as determined by the maximum standardized uptake value were retrieved. The sensitivity and specificity in predicting occult metastasis were calculated with a fourfold table. Associations between occult metastasis and clinicopathological variables were evaluated by univariate and multivariate analyses. The main study endpoints were locoregional control (LRC) and disease-specific survival (DSS).

Results

A total of 24 (20.3%) of 118 patients had occult metastasis. An MTV cutoff value of 4.3 cm³ showed a sensitivity of 50.0% and a specificity of 76.6% in predicting occult metastasis. The sensitivity and specificity of PET-CT in predicting occult metastasis in cT1 tumors were 66.6 and 89.8%, respectively, with values of 83.3 and 67.3%, respectively, when combined with the MTV. The sensitivity and specificity of PET-CT in predicting occult metastasis in cT2 tumors were 72.2 and 82.2%, respectively, with values of 88.9 and 57.8%, respectively, when combined with the MTV. Patients with MTV ≥4.3 cm³ had a higher occult metastasis rate than patients with MTV <4.3 cm³. The 5-year LRC and DSS rates were 86 and 94%, respectively, in patients with MTV <4.3 cm³ and 54 and 72%, respectively, in patients with MTV ≥4.3 cm³. Both differences were found to be significant in univariate and multivariate analyses.

Conclusions

MTV ≥4.3 cm³ was associated with an increased probability of occult metastasis and lower LRC and DSS rates in early-stage SCC of the tongue.

CT and FDG-PET radiologic biomarkers in p16+ oropharyngeal squamous cell carcinoma patients treated with definitive chemoradiotherapy

PURPOSE

To assess associations between imaging biomarkers from standard of care pre-treatment CT and FDG-PET scans and locoregional (LR) and distant metastatic (DM) recurrences in patients with p16+ oropharyngeal squamous cell carcinoma (OPSCC) treated with definitive chemoradiotherapy (CRT).

METHODS

An institutional database from a single NCI-designated cancer center identified 266 patients with p16+ OPSCC treated with definitive CRT in our department from 2005 to 2016 with evaluable pre-treatment FDG-PET scans. Quantitative SUV metrics and qualitative imaging metrics were determined from FDG-PET and CT scans, while clinical characteristics were abstracted from the medical record. Associations between clinical/imaging features and time to LR (TTLRF) or DM (TTDMF) failure and overall survival (OS) were assessed using univariable Cox regression and penalized stepwise regression for multivariable analyses (MVA).

RESULTS

There were 27 LR and 32 DM recurrences as incident failures. Imaging biomarkers were significantly associated with TTLRF, TTDMF and OS. FDG-PET metrics outperformed CT and clinical metrics for TTLRF, with metabolic tumor volume being the only significant feature selected on MVA: C-index = 0.68 (p = 0.01). Radiographic extranodal extension (rENE), positive retropharyngeal nodes (RPN+), and clinical stage were significant on MVA for TTDMF: C-index = 0.84 (p < 0.001). rENE, group stage, and RPN+ were significant on MVA for OS: C-index = 0.77 (p < 0.001).

CONCLUSIONS

In the largest study to date of uniformly treated patients with CRT to evaluate both pretreatment CT and FDG-PET, radiographic biomarkers were significantly associated with TTLRF, TTDMF and OS among patients with p16+ OPSCC treated with CRT. CT metrics performed best to predict TTDMF, while FDG-PET metrics showed improved prediction for LRRFS. These metrics may help identify candidates for treatment intensification or de-escalation of therapy.

STATEMENT OF TRANSLATIONAL RELEVANCE

Pre-treatment imaging features from standard-of-care PET/CT imaging show promise for predicting long-term outcomes following HPV-associated oropharynx cancer (HPV-OPC) therapy. This study comprehensively characterizes qualitative and quantitative pre-treatment imaging metrics associated with time to pattern-specific failure in a cohort of 266 patients treated uniformly with definitive chemoradiation. Multivariate analysis (MVA) for time to locoregional failure (TTLRF), time to distant metastatic failure (TTDMF), and overall survival (OS) was performed. FDG-PET metrics outperformed CT and clinical metrics for TTLRF. CT radiographic extranodal extension, positive retropharyngeal nodes, and stage strongly predicted TTDMF (combined C-index = 0.84, log rank p < 0.001). Number of smoking pack-years complemented clinical and imaging features only in patients without radiographic extranodal extension or positive retropharyngeal nodes. Time to pattern-specific failure is important for guiding treatment de-escalation strategies, which intend to reduce treatment-related toxicity in patients with relatively long expected survival times. This study suggests that PET/CT features should play a crucial role in future de-escalation trials and management of HPV-OPC patients.