Lesion regression rate based on RECIST: prediction of treatment outcome in patients with head and neck cancer treated with chemoradiotherapy compared with FDG PET-CT

Prospective Study of PET/MRI Tumor Response During Chemoradiotherapy for Patients With Low-risk and Intermediate-risk p16-positive Oropharynx Cancer

OBJECTIVE

The objective of this study was to examine tumor response with positron emission tomography (PET)/magnetic resonance imaging (MRI) during chemoradiotherapy as a predictor of outcome in patients with p16-positive oropharynx cancer.

MATERIALS AND METHODS

Patients with p16-positive oropharynx cancer were treated with chemoradiotherapy. Low-risk (LR) disease was defined as T1-T3 and N0-2b and ≤10 pack-years and intermediate-risk (IR) disease as T4 or N2c-3 or >10 pack-years. Patients underwent a PET/MRI scan pretreatment and at fraction 10. Change in value of imaging means were analyzed by analysis of variance. K-means clustering with Euclidean distance functions were used for patient clustering. Silhouette width was used to determine the optimal number of clusters. Linear regression was performed on all radiographic metrics using patient and disease characteristics.

RESULTS

Twenty-four patients were enrolled with 7 LR and 11 IR patients available for analysis. Pretreatment imaging characteristics between LR and IR patients were similar. Patients with LR disease exhibited a larger reduction in maximum standardized uptake value (SUV) compared with IR patients (P<0.05). Cluster analysis defined 2 cohorts that exhibited a similar intratreatment response. Cluster 1 contained 7 of 7 LR patients and 8 of 11 IR patients. Cluster 2 contained 3 of 11 IR patients. Cluster 2 exhibited significant differences compared with cluster 1 in the change in primary tumor peak SUV and largest lymph node median SUV.

CONCLUSIONS

We identified that IR p16-positive oropharynx cancers exhibit heterogeneity in their PET/MRI response to chemoradiotherapy. These data support further study of intratreatment imaging response as a potential mechanism to identify patients with IR oropharynx cancer suitable for treatment deintensification.

PET/CT-Based Response Evaluation in Cancer-a Systematic Review of Design Issues

Positron emission tomography/x-ray computed tomography (PET/CT) has long been discussed as a promising modality for response evaluation in cancer. When designing respective clinical trials, several design issues have to be addressed, especially the number/timing of PET/CT scans, the approach for quantifying metabolic activity, and the final translation of measurements into a rule. It is unclear how well these issues have been tackled in quest of an optimised use of PET/CT in response evaluation. Medline via Ovid and Science Citation Index via Web of Science were systematically searched for articles from 2015 on cancer patients scanned with PET/CT before and during/after treatment. Reports were categorised as being either developmental or evaluative, i.e. focusing on either the establishment or the evaluation of a rule discriminating responders from non-responders. Of 124 included papers, 112 (90 %) were accuracy and/or prognostic studies; the remainder were response-curve studies. No randomised controlled trials were found. Most studies were prospective (62 %) and from single centres (85 %); median number of patients was 38.5 (range 5-354). Most (69 %) of the studies employed only one post-baseline scan. Quantification was mainly based on SUVmax (91 %), while change over time was most frequently used to combine measurements into a rule (79 %). Half of the reports were categorised as developmental, the other half evaluative. Most development studies assessed only one element (35/62, 56 %), most frequently the choice of cut-off points (25/62, 40 %). In summary, the majority of studies did not address the essential open issues in establishing PET/CT for response evaluation. Reasonably sized multicentre studies are needed to systematically compare the many different options when using PET/CT for response evaluation.

Functional Imaging to Predict Treatment Response in Head and Neck Cancer: How Close are We to Biologically Adaptive Radiotherapy?

It is increasingly recognised that head and neck cancer represents a spectrum of disease with a differential response to standard treatments. Although prognostic factors are well established, they do not reliably predict response. The ability to predict response early during radiotherapy would allow adaptation of treatment: intensifying treatment for those not responding adequately or de-intensifying remaining therapy for those likely to achieve a complete response. Functional imaging offers such an opportunity. Changes in parameters obtained with functional magnetic resonance imaging or positron emission tomography-computed tomography during treatment have been found to be predictive of disease control in head and neck cancer. Although many questions remain unanswered regarding the optimal implementation of these techniques, current, maturing and future studies may provide the much-needed homogeneous cohorts with larger sample sizes and external validation of parameters. With a stepwise and collaborative approach, we may be able to develop imaging biomarkers that allow us to deliver personalised, biologically adaptive radiotherapy for head and neck cancer.

Association of Fludeoxyglucose F 18-Labeled Positron Emission Tomography and Computed Tomography With the Detection of Oropharyngeal Cancer Recurrence

Importance

No guidelines at present describe when fludeoxyglucose F 18-labeled positron emission tomography and computed tomography (FDG PET-CT) should be used in the initial posttreatment period for evaluation of oropharyngeal squamous cell carcinoma treatment outcome and recurrence.

Objective

To compare accuracies of the initial posttreatment PET-CT between primary treatment groups and to define indicators of false-positive findings.

Design, Setting, and Participants

This retrospective cohort study identified adults with a new diagnosis of oropharyngeal squamous cell carcinoma who received treatment with curative intent from October 1, 2006, through November 30, 2016, using the Alberta Cancer Registry (n = 380). Patients who underwent PET-CT within 1 year of treatment completion were included (n = 190). Of these, 103 patients (54.2%) had PET-CT findings positive for residual or recurrent disease, and 61 (32.1%) had false-positive findings. Among the 61 patients, 42 (68.9%) had received chemoradiotherapy (CRT) and 19 (31.1%) had primary surgery. Forty-two patients had true-positive findings, indicating a prevalence rate of disease of 22.1%. Data were analyzed from July through October 2017.

Exposures

One of 2 primary treatment modalities (surgery with or without adjuvant therapy vs CRT). All patients had posttreatment FDG PET-CT.

Main Outcomes and Measures

Primary outcome measures included the diagnostic odds ratio, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of PET-CT for detecting residual and/or recurrent disease. A multivariate analysis determined indicators of false-positive findings. Discriminative ability was assessed using receiver operating characteristic curve analysis of maximum standardized uptake value (SUVmax) metabolic data.

Results

Of the 190 participants, 77.9% were men, with a mean (SD) age at diagnosis of 58.5 (8.5) years. The diagnostic odds ratio was 19.3 (95% CI, 5.7-65.1); pooled sensitivity, 93.3% (95% CI, 80.7%-98.3%); and pooled specificity, 57.9% (95% CI, 49.4%-66.0%). The PPV of detecting disease was 54.7% (95% CI, 38.8%-69.8%) for primary surgery and 31.1% (95% CI, 20.2%-44.4%) for CRT. The NPV was 100% (95% CI, 94.7%-100%) for primary surgery and 96.6% (95% CI, 89.5%-99.1%) for CRT. Multivariate analysis identified treatment type, p16 disease, and smoking status as indicative of false-positive findings. In the receiver operating characteristic curve analysis for primary tumors, the optimal cutoff SUVmax for indicating true- vs false-positive results was 5.1 for surgically treated patients (area under the curve, 0.729; 95% CI, 0.570-0.888) and 5.3 for patients treated with CRT (area under the curve, 0.844; 95% CI, 0.700-0.989).

Conclusions and Relevance

The results indicate a higher specificity for FDG PET-CT for initial posttreatment surveillance imaging among patients treated with primary surgery compared with nonsurgical management. Both sets of patients with posttreatment FDG PET-CT findings with an SUVmax greater than 5.0 should undergo close evaluation for possible residual or recurrent disease.

Rerouting Geriatric Medicine by Complementing Static Frailty Measures With Dynamic Resilience Indicators of Recovery Potential

Medicine is still very inadequate in forecasting recovery of tipping points in health and disease, especially in older adults. However, increasingly, diseases and invasive treatments unexpectedly push older patients with low resilience over their tipping points (TPs). These TPs are the points in human physiology that separate more healthy conditions from disease conditions or malfunctioning of the older human’s subsystems or organs, such as delirium, syncope and falls in old age, which threaten the functioning of the older person as a whole. Either the person may recover from the perturbation induced by such a subsystem TP and the balance of the whole system is restored, or the TP may set in motion a cascade of events driving the system down to a state of more decline, ultimately leading to death. A main unanswered question here is how to predict whether these older persons will recover or not. To improve this TP-recovery-forecasting, intriguing findings on measures of resilience found in other complex biological systems may be translated to humans. New dynamic resilience biomarkers for resilience can enrich clinical prediction for pathophysiological recovery and could test interventions for their effectiveness in improving resilience. Therefore, we hypothesize that dynamic, stimulus-response measures of recovery rate over time, observed after having received a minor stressor in a healthy condition, can be used to quantify recovery potential following subsystem TPs in disease and following invasive treatments in humans and thus the person’s resilience. Current static frailty prognostics can predict risks for death, institutionalization, delirium, falls, and other TP transitions, but it has not been proven that they can predict recovery. Our hypothesis on dynamic indicators of recovery is logical and timely, as it can now be studied with sensor technology to create a fundamentally different approach of variables that may be validated to forecast recovery potential. By generating dynamic measures of systemic resilience over various organ systems, we may subsequently model resilience generically across many chronic diseases, affecting different organ systems. Next, quantifying systemic resilience may reroute scientific and clinical pathways by predicting and preventing irreversible tipping points and by improving recovery by older adults.

Functional imaging early during (chemo)radiotherapy for response prediction in head and neck squamous cell carcinoma; a systematic review

This systematic review gives an extensive overview of the current state of functional imaging during (chemo)radiotherapy to predict locoregional control (LRC) and overall survival (OS) for head and neck squamous cell carcinoma. MEDLINE and EMBASE were searched for literature until April 2018 assessing the predictive performance of functional imaging (computed tomography perfusion (CTp), MRI and positron-emission tomography (PET)) within 4 weeks after (chemo)radiotherapy initiation. Fifty-two studies (CTp: n = 4, MRI: n = 19, PET: n = 26, MRI/PET: n = 3) were included involving 1623 patients. Prognostic information was extracted according the PRISMA protocol. Pooled estimation and subgroup analyses were performed for comparable parameters and outcome. However, the heterogeneity of included studies limited the possibility for comparison. Early tumoral changes from (chemo)radiotherapy can be captured by functional MRI and ¹⁸F-FDG-PET and could allow for personalized treatment adaptation. Lesions showed potentially prognostic intratreatment changes in perfusion, diffusion and metabolic activity. Intratreatment ADC_mean increase (decrease of diffusion restriction) and low SUV_max (persistent low or decrease of ¹⁸F-FDG uptake) were most predictive of LRC. Intratreatment persistent high or increase of perfusion on CT/MRI (i.e. blood flow, volume, permeability) also predicted LRC. Low SUV_max and total lesion glycolysis (TLG) predicted favorable OS. The optimal timing to perform functional imaging to predict LRC or OS was 2-3 weeks after treatment initiation.

Assessment of tumor response to chemoradiotherapy and predicting prognosis in patients with head and neck squamous cell carcinoma by PERCIST

PURPOSE

To evaluate therapeutic response to chemoradiotherapy and prediction of recurrence and death in patients with head and neck squamous cell carcinoma (HNSCC) using Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST).

MATERIALS AND METHODS

Forty-two patients (mean 63.4, range 20-79 years) with nasopharyngeal (n = 10), oropharyngeal (n = 13), hypopharyngeal (n = 11), or laryngeal (n = 8) cancer underwent fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) before and approximately 3 months (mean 95.0, range 70-119 days) after undergoing concurrent chemoradiotherapy. The effect of PERCIST regarding progression-free survival (PFS) and overall survival (OS) was examined using log-rank and Cox methods.

RESULTS

Complete metabolic response (CMR), partial metabolic response (PMR), stable metabolic disease (SMD), and progressive metabolic disease shown by PERCIST were seen in 30 (71.4%), 9 (21.4%), 3 (7.1%), and 0 patients, respectively. Fourteen (33.3%) developed recurrent disease (median follow-up 27.2, range 8.7-123.1 months) and 9 (21.4%) died (median follow-up 43.6, range 9.6-132.6 months). Furthermore, 4 (13.3%) of 30 patients with CMR developed recurrence, while 7 (77.8%) of 9 with PMR and all 3 (100%) with SMD developed recurrence. Two (6.7%) of 30 patients with CMR, 4 (44.4%) of 9 with PMR, and all 3 (100%) with SMD died. Patients who achieved CMR showed significantly longer PFS and OS as compared to those who did not (PMR and SMD) (both, p < 0.0001).

CONCLUSION

PERCIST is useful for evaluating therapeutic response to chemoradiotherapy and predicting recurrence and death in HNSCC patients.

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.

Overview of the predictive value of quantitative 18 FDG PET in head and neck cancer treated with chemoradiotherapy

18 F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) allows to quantify the metabolic activity of a tumor (glycolysis) and has become a reference tool in oncology for the staging, restaging, radiotherapy planning and monitoring response in many cancers. Quantitative analyses have been introduced in order to overcome some of the limits of the visual methods, allowing an easier and more objective comparison of the inter- and intra-patients variations. The aims of this review were to report available evidences on the clinical value of quantitative PET/CT parameters in HNC. Forty-five studies, for a total of 2928 patients, were analyzed. Most of the data available dealt with the intensity of the metabolism, calculated from the Standard Uptake Value (SUV). Metabolic Tumor Volume (MTV) was well correlated with overall survival and disease free survival, with a higher predictive value than the maximum SUV. Spatial distribution of metabolism and textural analyses seems promising.