Does a 6-point scale approach to post-treatment 18F-FDG PET-CT allow to improve response assessment in head and neck squamous cell carcinoma? A multicenter study

The Christie score for post-treatment response assessment PET/CT in patients with head and neck squamous cell carcinoma: a safe and simple scoring system

BACKGROUND

Radiotherapy with or without concurrent chemotherapy is a standard of care treatment for patients with head and neck squamous cell carcinoma (HNSCC). Upon completion, patients are referred for a post-treatment 18F-FDG PET/CT (Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography) scan to help guide ongoing management by assessing for the presence or absence of residual or recurrent disease and differentiating this from post-treatment inflammation. To improve objective reporting of response, we developed the Christie score. The study aims to assess the validity of the Christie score as a response assessment tool in patients with HNSCC and to compare its performance against the widely used Hopkins score.

METHODS AND MATERIALS

All newly diagnosed head and neck cancers between July 2018 and July 2020 were retrospectively reviewed. In total, 291 patients (224 men and 67 women) were included in the study. Patients with squamous cell carcinoma of the nasopharynx, oropharynx or oral cavity, hypopharynx or larynx were included. All other cell lineages or anatomical locations were excluded. Hopkins and Christie scores were applied to post-treatment PET/CT, and sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratio assessed for each score. Fisher's exact tests and receiver-operating characteristic (ROC) curves were used to determine the ability of the Hopkins and Christie scores to differentiate residual or recurrent disease from treatment response. p values < 0.05 were considered to indicate statistical significance.

RESULTS

39 patients (13%) were confirmed to have residual or recurrent disease. This was significantly more likely in patients with positive Hopkins (p < 0.0001) and Christie (p < 0.0001) scores. The Christie score has a higher sensitivity (92% vs. 85%) and negative predictive value (99% vs. 97%) compared to Hopkins, though the differences were not statistically significant. Comparison of the ROC curves for the Hopkins and Christie score revealed no significant difference between the two scores' ability to discriminate patients with residual or recurrent disease from cases where disease is absent (p = 0.382). 'Subjectivity rates' of the 291 patients are as follows. Six patients (2.1%; 95% CI 0.76-4.5%) were assigned borderline scores on the Hopkins criteria, compared to only a single patient (0.3%; 95% CI 0-1.9%) on the Christie criteria. The 'subjectivity rate' difference is 0.017 (95% CI - 0.06 to 3.5%; p = 0.06) and the ratio is 6.0 (95% CI 0.73-276; p = 0.07).

CONCLUSION

Our study identifies three clear results: (a) the Christie score is an excellent treatment follow-up assessment tool; (b) it is comparable with current gold standard methodology showing no statistically significant differences in performance when compared with the Hopkins score; and (c) there was a lower rate of observer variation when using the Christie score, which is trending towards significance.

Radiographic Response Assessments and Standardized Imaging Interpretation Criteria in Head and Neck Cancer on FDG PET/CT: A Narrative Review

INTRODUCTION

There is growing interest in the development and application of standardized imaging criteria (SIC), to minimize variability and improve the reproducibility of image interpretation in head and neck squamous cell carcinoma (HNSCC).

METHODS

"Squamous cell carcinoma" AND "standardized interpretation criteria" OR "radiographic response assessment" were searched using PubMed and Google Scholar for articles published between 2009 and 2024, returning 56 publications. After abstract review, 18 were selected for further evaluation, and 6 different SICs (i.e., PERCIST, Porceddu, Hopkins, NI-RADS, modified Deauville, and Cuneo) were included in this review. Each SIC is evaluated in the context of 8 desired traits of a standardized reporting system.

RESULTS

Two SICs have societal endorsements (i.e., PERCIST, NI-RADS); four can be used in the evaluation of locoregional and systemic disease (i.e., PERCIST, Hopkins, NI-RADS, Cuneo), and four have specific categories for equivocal imaging results (i.e., Porceddu, NI-RADS, modified Deauville, and Cuneo). All demonstrated areas for future improvement in the context of the 8 desired traits.

CONCLUSION

Multiple SICs have been developed for and demonstrated value in HNSCC post-treatment imaging; however, these systems remain underutilized. Selecting an SIC with features that best match the needs of one's practice is expected to maximize the likelihood of successful implementation.

Roles and mechanisms of circular RNA in respiratory system cancers

Circular RNAs (circRNAs) constitute a class of endogenous non-coding RNAs (ncRNAs) that lack a 5'-ended cap and 3'-ended poly (A) tail and form a closed ring structure with covalent bonds. Due to its special structure, circRNA is resistant to Exonuclease R (RNaseR), making its distribution in the cytoplasm quite rich. Advanced high-throughput sequencing and bioinformatics methods have revealed that circRNA is highly conserved, stable, and disease- and tissue-specific. Furthermore, increasing research has confirmed that circRNA, as a driver or suppressor, regulates cancer onset and progression by modulating a series of pathophysiological mechanisms. As a result, circRNA has emerged as a clinical biomarker and therapeutic intervention target. This article reviews the biological functions and regulatory mechanisms of circRNA in the context of respiratory cancer onset and progression.

Prognostic value of [18F]-FDG PET/CT in patients with meta-static breast cancer treated with cyclin-dependent inhibitors

Objective

The addition of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) to endocrine therapy impressively improved the outcome of patients with hormone receptor-positive metastatic breast cancer. Despite their great efficacy, not all patients respond to treatment and many of them develop acquired resistance. The aim of this retrospective study was to assess the role of [18F]-FDG PET/CT in predicting PFS and OS in breast cancer patients treated with CDK4/6i.

Methods

114 patients who performed an [18F]-FDG PET/CT scan before (PET1) and 2-6 months (PET2) after starting treatment were retrospectively enrolled. Metabolic response was evaluated by EORTC, PERCIST and Deauville Score and correlated to PFS and OS.

Results

In patients who did not progress at PET2 (n = 90), PFS rates were not significantly different between classes of response by EORTC and PERCIST. Conversely, patients showing a Deauville score ≤3 had a longer PFS (median PFS 42 vs 21.0 months; p = 0.008). A higher total metabolic tumor volume at PET1 (TMTV1) was also associated with a shorter PFS (median 18 vs 42 months; p = 0.0026). TMTV1 and Deauville score were the only independent prognostic factors for PFS at multivariate analysis and their combination stratified the population in four definite classes of relapse risk. Conversely, the above parameters did not affect OS which was only influenced by a progressive metabolic disease at PET2 (3-years survival rate 29.8 vs 84.9%; p<0.0001).

Conclusion

TMTV and metabolic response by Deauville score were significant prognostic factors for PFS in patients with breast cancer treated with CDK4/6i. Their determination could help physicians to select patients who may need a closer follow up.

[18F]FDG PET/CT in head and neck squamous cell carcinoma: a head-to-head between visual point-scales and the added value of multi-modality imaging

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) represents the 6th leading cancer worldwide. In most cases, patients present a locally advanced disease at diagnosis and non-surgical curative treatment is considered the standard of care. Nowadays, [¹⁸F]FDG PET/CT is a validated tool in post-treatment evaluation, with a high level of evidence. However, to standardize imaging response, several visual scales have been proposed with none of them approved yet. The study's aim is a head-to-head comparison between the diagnostic performance of the Hopkins criteria, the Deauville score, and the new proposed Cuneo score, to establish their prognostic role. Secondly, we investigate the possible value of semiquantitative analysis, evaluating SUV_max and ΔSUV_max of the lymph node with the highest uptake on the restaging PET scan. Moreover, we also considered morphological features using the product of diameters measured on the co-registered CT images to assess the added value of hybrid imaging.

METHODS

We performed a retrospective analysis on histologically proven HNSCC patients who underwent baseline and response assessment [¹⁸F]FDG PET/CT. Post-treatment scans were reviewed according to Hopkins, Deauville, and Cuneo criteria, assigning a score to the primary tumor site and lymph nodes. A per-patient final score for each scale was chosen, corresponding to the highest score between the two sites. Diagnostic performance was then calculated for each score considering any evidence of locoregional progression in the first 3 months as the gold standard. Survival analysis was performed using the Kaplan-Meier method. SUV_max and its delta, as well as the product of diameters of the lymph node with the highest uptake at post-treatment scan, if present, were calculated.

RESULTS

A total of 43 patients were finally included in the study. Sensitivity, specificity, PPV, NPV, and accuracy were 87%, 86%, 76%, 92%, and 86% for the Hopkins score, whereas 93%, 79%, 70%, 96%, and 84% for the Deauville score, respectively. Conversely, the Cuneo score reached the highest specificity and PPV (93% and 78%, respectively) but the lowest sensitivity (47%), NPV (76%), and accuracy (77%). Each scale significantly correlated with PFS and OS. The ROC analysis of the combination of SUV_max and the product of diameters of the highest lymph node on the restaging PET scan reached an AUC of 0.822. The multivariate analysis revealed the Cuneo criteria and the product of diameters as prognostic factors for PFS.

CONCLUSIONS

Each visual score statistically correlated with prognosis thus demonstrating the reliability of point-scale criteria in HNSCC. The novel Cuneo score showed the highest specificity, but the lowest sensibility compared to Hopkins and Deauville criteria. Furthermore, the combination of PET data with morphological features could support the evaluation of equivocal cases.