Prognostic value of metabolic tumor volume and total lesion glycolysis in head and neck cancer: a systematic review and meta-analysis

Prognostic Value of the Metabolic Response on Serial 18F-FDG PET/CT in Pancreatic Cancer

Background/Aims

The prognostic value of serial 18F-fluorodeoxyglucose positron emission tomography/ computed tomography (18F-FDG PET/CT) for patients with borderline resectable or locally advanced pancreatic cancer who undergo conversion surgery or continue chemotherapy without surgery has not been well-established.

Methods

A retrospective analysis of patients with pancreatic ductal adenocarcinoma was conducted at Seoul National University Bundang Hospital between March 2013 and February 2022. Patients underwent PET/CT at baseline and subsequent radiologic evaluations following chemotherapy. Changes in the maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume, and total lesion glycolysis were analyzed. Based on their treatment regimens, patients were stratified into the conversion surgery group or nonconversion surgery group. Survival outcomes and various clinical factors were assessed.

Results

Among 121 patients, 52 underwent conversion surgery, and 69 continued to receive chemotherapy without surgery. A significant reduction in the SUVmax was correlated with prolonged recurrence-free survival and overall survival in the conversion surgery group. Confirmation of a pathologic response indicated a significant association between reductions in the SUVmax and positive outcomes. Reductions in the metabolic tumor volume and total lesion glycolysis were associated with improved progression-free survival and overall survival in the nonconversion surgery group.

Conclusions

Serial PET/CT scans demonstrated prognostic value in pancreatic ductal adenocarcinoma patients, revealing distinct correlations in the conversion surgery group and nonconversion surgery group.

PET-based Quantitative Techniques in Assessing Efficacy of Interventional Radiology Procedures in Oncology

Interventional radiology (IR) is a super specialised branch where imaging modalities are employed to guide disease specific diagnostic and therapeutic interventions. IR interventions have gained popularity in various oncological and non-oncological indications due to it's ability to effectively diagnose the disease and direct specific targeted treatment. Hybrid imaging using PET CT and PET MRI combines the best of morphological and functional informations and offers improved sensitivity and specificity for detection of lesion; helps in accurate mapping of tumour burden, thereby aiding in planning curative vs palliative intent intervention; more accurate response evaluation to plan redo session in cases of residual / recurrent disease or for follow up evaluation and for prognostication and predicting response. Albeit visual analysis of PET images by specialist is most commonly performed for reading PET scans, PET has a remarkable capability to provide quantitative information. The present review provides a comprehensive assessment of the role of various aspects of quantitative PET parameters in assessing the efficacy of IR interventions. The insights provided will help clinicians, researchers, and medical professionals understand the role of PET imaging in advancing patient care and enhancing the therapeutic outcomes of IR procedures.

[18F]FDG PET/CT Imaging and Hematological Parameters Can Help Predict HPV Status in Head and Neck Cancer

To determine whether [18F]FDG PET/CT and hematological parameters provide supportive data to determine HPV status in HNSCC patients.Retrospective analysis of clinical and diagnostic data from 106 patients with HNSCC: 26.4% HPV-positive and 73.6% HPV-negative was performed. The following semiquantitative PET/CT parameters for the primary tumor and hottest lymph node and liver were evaluated: SUVmax, SUVmean, TotalSUV, MTV, TLG, maximum, mean and TLG tumor-to-liver ratio (TLRmax, TLRmean,TLRTLG) and heterogeneity index (HI). Following hematological variables were assessed: white blood cell (WBC); lymphocyte (LYMPH); neutrophil (NEU),monocyte (MON); platelet (PLT); neutrophil-to-lymphocyte ratio (NRL); lymphocyte-to-monocyte ratio (LMR); platelet-to lymphocyte ratio (PLR) and monocyte-to-lymphocyte ratio (MLR). Conventional statistical analyses were performed in parallel with an artificial neural network analysis (Neural Analyzer, v. 2.9.5).Significant between-group differences were observed for two of the semiquantitative PET/CT parameters, with higher values in the HPV-negative group: primary tumor MTV (22.2 vs 9.65; p=0.023), and TLRmax (3.50 vs 2.46; p=0.05). The HPV-negative group also had a significantly higher NEU count (4.84 vs. 6.04; p=0.04), NEU% (58.2 vs. 66.2; p=0.007), and NRL% (2.69 vs. 3.94; p=0.038). Based on ROC analysis (sensitivity 50%, specificity 80%, AUC 0.5), the following variables were independent predictors of HPV-negativity: primary tumor with SUVmax >10; TotalSUV >2800; MTV >23.5; TLG >180; TLRmax >3.7; TLRTLG >5.7; and oropharyngeal localization.Several semiquantitative parameters derived from [18F]FDG PET/CT imaging of the primary tumor (SUVmax, TotalSUV, MTV, TLG, TLRmax and TLRTLG) were independent predictors of HPV-negativity.

Association between apolipoprotein E ε4 status and the risk of Alzheimer's disease: a meta-analysis

BACKGROUND

The apolipoprotein E ε4 (APOE ε4) status has a controversial role in predicting Alzheimer's disease (AD) factors. This meta-analysis assessed AD event risk in patients with APOE ε4 status.

MATERIALS AND METHODS

The relevant English-language articles were identified by searching the Cochrane Library, EMBASE, and PubMed databases. The prognostic significance of APOE ε4 status in AD patients was examined on the basis of pooled hazard ratios (HRs).

RESULTS

A total of 22 studies published after 1987, including 571,800 patients, were included. Consequently, APOE ε4 status was a risk factor for disease-free survival (DFS, HR = 2.033; 95% confidence interval [CI] = 1.589-2.602; P = 0.000; I 2 = 93.1%) in patients with AD. Additionally, subgroup analysis suggested that the ROC curve was the main risk factor among patients with AD.

CONCLUSIONS

AD patients with different events are managed via different methods; however, the present meta-analysis suggests an increased risk of AD events in patients with different APOE ε4 statuses.

PET-Assessed Metabolic Tumor Volume Across the Spectrum of Solid-Organ Malignancies: A Review of the Literature

Solid-organ malignancies represent a significant disease burden and remain one of the leading causes of death globally. In the past few decades, the rapid evolution of imaging modalities has shifted the paradigm towards image-based precision medicine, especially in the care of patients with solid-organ malignancies. Metabolic tumor volume (MTV) is one such semi-quantitative parameter obtained from positron emission tomography (PET) imaging with 18F-fluorodeoxyglucose (FDG) that has been shown to have significant implications in the clinical oncology setting. Across various solid tumor malignancies, including lung cancer, head and neck cancer, breast cancer, esophageal cancer, and colorectal cancer, the current literature has demonstrated an association between MTV and various clinical outcomes. MTV may be used in conjunction with several existing and established clinical parameters to help inform risk stratification and treatment strategies and predict outcomes in cancer. Optimizing such volumetric parameters is paramount for advancing efforts to advance cancer care for our patients. While such advancements are made, it is important to investigate and address the limitations of MTV, including variability in terms of measurement methods, a lack of standardized cut-off values, and the impact of inherent tumor heterogeneity. Despite these limitations, which can precipitate challenges in standardization, MTV as a prognostic factor has great potential and opens an avenue for the future integration of technology into an image-based precision medicine model of care for cancer patients. This article serves as a narrative review and explores the utility and limitations of PET-MTV in various settings of solid-organ malignancy.

18 F-FDG PET Metabolic Parameters for the Prediction of Histological Response to Induction Chemotherapy in Osteosarcoma and Ewing Sarcoma : A Systematic Review and Network Meta-analysis

PURPOSE

This study aimed to evaluate the ability of 18 F-FDG PET/CT metabolic parameters to predict the histological response to neoadjuvant chemotherapy in patients with osteosarcoma and Ewing sarcoma.

PATIENTS AND METHODS

This systematic review and network meta-analysis adhered to the PRISMA-NMA and Cochrane guidelines. Electronic databases were searched from January 2008 to January 2024; this search was supplemented by snowballing methods. The risk of bias was evaluated with QUADAS-2, and evidence certainty was assessed using the GRADE approach. The prognostic value of 18 F-FDG PET/CT parameters, including pretreatment and posttreatment SUVs (SUV1, SUV2 and the SUV2/SUV1 ratio), metabolic tumor volume (MTV1, MTV2, ΔMTV), and total lesion glycolysis (TLG1, TLG2, ΔTLG), was examined.

RESULTS

The meta-analysis of 18 studies (714 patients) identified the ΔTLG, ΔMTV, and SUV ratio as superior predictors of histological response. The changes in metabolic activity, as indicated by these parameters, provided a robust indication of treatment effectiveness. Baseline parameters showed limited predictive value compared with posttreatment assessments. The study's robustness was confirmed through meta-regression, which revealed that the predictive value of the SUV2 and SUV ratio was consistent across various cutoff thresholds.

CONCLUSIONS

18 F-FDG PET/CT metabolic parameters, particularly those measuring changes posttherapy, are effective in predicting the histological response in patients with osteosarcoma and Ewing sarcoma. These findings underscore the potential of 18 F-FDG PET/CT in guiding early treatment decisions, thereby enhancing personalized therapeutic approaches.

Prognostic Value of the 18F-FDG PET/CT and Haematological Parameters in Head and Neck Cancer

INTRODUCTION

Fluorine 18-fluoro-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) is commonly used for the staging of head and neck cancer. This study aimed to evaluate the correlation between 18F-FDG PET/CT, haematological parameters and prognosis in patients with advanced head and neck cancer.

METHODS

This was a single-institutional retrospective study of 83 patients with advanced head and neck squamous cell carcinoma (HNSCC) who underwent 18F-FDG PET/CT imaging before initial treatment between 2014 and 2018. 18F-FDG PET/CT after treatment was performed in 57 patients. The prognostic parameters of the pre- and post-treatment maximum standardised uptake value (SUVmax), metabolic tumour volume (MTV), total lesion glycolysis (TLG) of primary tumours and haematological parameters were analysed to evaluate the association between overall survival (OS) and progression-free survival (PFS).

RESULTS

Pre-MTV, pre-TLG and post-SUVmax were significantly associated with poor OS and PFS (p < 0.05). Haematological parameters, including pretreatment neutrophil/lymphocyte ratio and C-reactive protein/albumin ratio, were associated with 18F-FDG PET/CT parameters. In multivariate analysis, post-SUVmax was an independent prognostic factor for OS and PFS.

CONCLUSION

A correlation between PET/CT metabolic and haematological parameters was observed. The volume and intensity of 18F-FDG uptake region, in addition to haematological parameters, are feasible markers for predicting the progression of HNSCC in daily practice. Further, post-SUVmax could be an independent parameter for predicting poor survival.

Prognostic Importance of 18F-FDG Positron Emission Tomography in Uterine Cervical Cancer

Objectives

The aim of this study was to evaluate the prognostic value of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in the uterine cervix cancer patients.

Methods

Thirty-two women (mean age: 52.7±12.6) who underwent 18F-FDG PET/CT for staging of uterine cervix cancer were retrospectively recruited for the study. Maximum standardized uptake value (SUVmax), SUVmean, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for primary tumors, lymph nodes, and distant metastases were calculated from 18F-FDG PET/CT images using the 40% threshold. Patients were divided into groups according to the presence of pelvic and para-aortic lymph node involvement on 18F-FDG PET/CT images. Life tables and Kaplan-Meier analyses were performed to compare the mean survival times of the different groups.

Results

Primary tumor of 27 (84%) patients were 18F-FDG avid. The median SUVmax, SUVmean, MTV, and TLG of the primary tumors were 12.4, 6.1, 13.2 cm3 and 87.8 g/mL x cm3 respectively. Pathological uptake was detected in pelvic 14 (44%) patients and in paraaortic lymph nodes in 3 (10%) para-aortic lymph nodes. The median whole-body MTV and TLG were 21.7 cm3 and 91.1 g/mL x cm3. Disease progression was detected in 7 (22%) patients within a median follow-up period of 20.9 (minimum-maximum: 3-82) months. The only significant PET parameter to predict progression-free survival was SUVmax in the primary tumor (p=0.038). During follow-up period 8 patients died. SUVmax (p=0.007), MTV (p=0.036), TLG (p=0.001) of primary tumor, presence of pathological uptake on pelvic or paraaortic lymph nodes (p=0.015), whole-body MTV (p=0.047) and whole-body TLG (p=0.001) were found statistically significant PET parameters to predict overall survival.

Conclusion

Metabolic parameters of primary tumors derived from 18F-FDG PET/CT images have prognostic importance for patients with uterine cervical carcinoma. In patients with metastatic disease, higher whole-body MTV and TLG are also associated with poor prognosis.

Association between glaucoma and the risk of Alzheimer's disease: A meta-analysis

BACKGROUND

The role of glaucoma in predicting Alzheimer's disease (AD) factors is unknown. This current meta-analysis was aimed at evaluating the risk of AD events in individuals suffering from glaucoma based on a meta-analysis.

MATERIALS AND METHODS

Databases which included Cochrane Library, PubMed, and EMBASE were searched to detect the relevant articles, with language being restricted to English. The risk of AD events in patients with glaucoma was analyzed using the combined hazard ratios.

RESULTS

This study included 8 articles with 131,987 subjects published after 2012. We identified glaucoma as the risk factor for disease-free survival (hazard ratio = 1.29; 95% confidence interval = 1.05-1.59; P = .000; I2 = 95.1%) in AD patients. According to subgroup analyses, normal tension glaucoma group was the major risk factor for disease-free survival of AD patients.

CONCLUSIONS

Although diverse approaches have been used for AD cases of various events, the current meta-analysis indicates that that glaucoma patients have a higher AD risk.

Prognostic significance of 68 Ga-FAPI PET/CT in patients with bone metastases in various cancers

OBJECTIVE

This study aimed to compare 18FDGPET/CT in patients who develop bone metastases due to various cancers and to investigate the prognostic significance of the 68FAPI-PET/CT SUVmax value for survival.

METHODS

Patients with bone metastases who underwent both 68 Ga-FAPI PET/CT and 18FDGPET/CT within a 1 week period were included in this retrospective study. The effect of the SUVmax value of bone lesions on overall survival was analyzed.

RESULTS

A total of 75 eligible patients with 139 bone lesions were included in this study. The median age of the patients was 55 (30-83) and 48(64%) patients were newly diagnosed. The primary lesion median 68 Ga-FAPI PET/CT SUVmax value was higher than the median 18FDGPET/CT SUVmax (10.75 versus 6.7). Bone lesions 68 Ga-FAPI PET/CT SUVmax median (IQR) were 7.8 (4.6-13.2), and 18FDGPET/CT SUVmax of bone lesions were 5.9 (3.8-8.2). More bone lesions were detected on 68 Ga-FAPI PET/CT than on 18FDGPET/CT(median IQR 4 [1-9] versus 2 [1-6] (p = 0.014). The extra lesions observed on 68 Ga-FAPI PET/CT were mostly sclerotic bone lesions (p = 0.001).68 Ga-FAPI PET/CT SUVmax was significantly higher in vertebra and thorax lesions (p = 0.011 and p = 0.018, respectively). While the bone lesion 68 Ga-FAPI PET/CT SUVmax affected the OS, the 18FDGPET/CT SUVmax value did not affect the OS (p < 0.001 and p = 0.079, respectively). In ROC analysis, a cut-off-off value of 68 Ga-FAPI PET/CT SUVmax > 7.7 was found for OS (AUC: 0.619). The median OS in the group above the cut-off value was worse than that in the group below the cut-off value (32 versus 45) months (p = 0.002). In the multivariate analysis for OS, the 68 Ga-FAPI PET/CT SUVmax of bone lesions was an important parameter, as well as cancer subtype, ALP level, and disease occurrence.

CONCLUSIONS

68 Ga-FAPI PET/CT detected more bone lesions and higher SUVmax values than 18FDGPET/CT in various cancers. The prognostic value of the SUVmax value of 68 Ga-FAPI PET/CT bone lesions was observed regardless of disease subtype.

Multi omics analysis of mitophagy subtypes and integration of machine learning for predicting immunotherapy responses in head and neck squamous cell carcinoma

Mitophagy serves as a critical mechanism for tumor cell death, significantly impacting the progression of tumors and their treatment approaches. There are significant challenges in treating patients with head and neck squamous cell carcinoma, underscoring the importance of identifying new targets for therapy. The function of mitophagy in head and neck squamous carcinoma remains uncertain, thus investigating its impact on patient outcomes and immunotherapeutic responses is especially crucial. We initially analyzed the differential expression, prognostic value, intergene correlations, copy number variations, and mutation frequencies of mitophagy-related genes at the pan-cancer level. Through unsupervised clustering, we divided head and neck squamous carcinoma into three subtypes with distinct prognoses, identified the signaling pathway features of each subtype using ssGSEA, and characterized subtype B as having features of an immune desert using various immune infiltration calculation methods. Using multi-omics data, we identified the genomic variation characteristics, mutated gene pathway features, and drug sensitivity features of the mitophagy subtypes. Utilizing a combination of 10 machine learning algorithms, we have developed a prognostic scoring model called Mitophagy Subgroup Risk Score (MSRS), which is used to predict patient survival and the response to immune checkpoint blockade therapy. Simultaneously, we applied MSRS to single-cell analysis to explore intercellular communication. Through laboratory experiments, we validated the biological function of SLC26A9, one of the genes in the risk model. In summary, we have explored the significant role of mitophagy in head and neck tumors through multi-omics data, providing new directions for clinical treatment.

Association Between Pretreatment 11C-Methionine Positron Emission Tomography Metrics, Histology, and Prognosis in 125 Newly Diagnosed Patients with Adult-Type Diffuse Glioma Based on the World Health Organization 2021Classification

OBJECTIVE

To clarify the relationships between 11C-methionine (MET) positron emission tomography (PET) metrics and the histology, genetics, and prognosis of adult-type diffuse glioma (ADG) based on the World Health Organization (WHO) 2021 classification.

METHODS

A total of 125 newly diagnosed patients with ADG were enrolled. We compared the maximum standardized uptake value (SUVmax), tumor-to-normal background ratio (TNR), metabolic tumor volume (MTV), and total lesion methionine uptake (TLMU) to the histology and genetics of the patients with ADG. We also evaluated the prognoses of the 93 surgically treated patients.

RESULTS

The patients with isocitrate dehydrogenase wild ADG showed significantly higher MET-PET metrics (P < 0.05 for all parameters), significantly shorter overall survival and progression-free survival (P < 0.0001 for both) than those of the patients with isocitrate dehydrogenase mutant (IDHm) ADG. In the IDHm ADG group, the SUVmax, MTV, and TLMU values were significantly higher in patients with IDHm grade (G) 4 astrocytoma than patients with IDHm G2/3 astrocytoma (P < 0.05 for all), but not than patients with G2-3 oligodendroglioma. The progression-free survival was significantly shorter in the patients with G4 astrocytoma versus the patients with G2/3 astrocytoma and G3 oligodendroglioma (P < 0.05 for both). The SUVmax and TNR values were significantly higher in recurrent patients than nonrecurrent patients (P < 0.01 for both), but no significant differences were found in MTV or TLMU values.

CONCLUSIONS

MET-PET metrics well reflect the histological subtype, WHO grade and prognosis of ADG based on the 2021 WHO classification, with the exception of oligodendroglial tumors. Volumetric parameters were not significantly associated with recurrence, unlike the SUVmax and TNR.

A comprehensive review of the role of bone marrow biopsy and PET-CT in the evaluation of bone marrow involvement in adults newly diagnosed with DLBCL

Diffuse large B cell lymphoma (DLBCL) is one of the most prevalent subtypes of non-Hodgkin lymphoma (NHL) and is known for commonly infiltrating extra-nodal sites. The involvement of the bone marrow by lymphoma cells significantly impacts the staging, treatment, and prognosis among the extra-nodal sites in DLBCL. Bone marrow biopsy has been considered the standard diagnostic procedure for detecting bone marrow involvement. However, advancements in imaging techniques, such as positron emission tomography-computed tomography (PET-CT), have shown an improved ability to detect bone marrow involvement, making the need for bone marrow biopsy debatable. This review aims to emphasize the importance of bone marrow evaluation in adult patients newly diagnosed with DLBCL and suggest an optimal diagnostic approach to identify bone marrow involvement in these patients.

Association of circulating tumor HPV16DNA levels and quantitative PET parameters in patients with HPV-positive head and neck squamous cell carcinoma

Circulating tumor DNA (ctDNA), which circulates in the blood after being shed from cancer cells in the body, has recently gained attention as an excellent tumor marker. The purpose of this study was to evaluate whether ct human papillomavirus (HPV) 16 DNA (ctHPV16DNA) levels were associated with quantitative PET parameters in patients with HPV-positive head and neck (HN) squamous cell carcinoma (SCC). Fifty patients with oropharyngeal SCC (OPSCC) and 5 with SCC of unknown primary (SCCUP) before treatment were included. They all underwent blood sampling to test ctHPV16DNA levels and FDG PET-CT examinations. Quantitative PET parameters included SUVmax, metabolic tumor volume (MTV), MTV of whole-body lesions (wbMTV), and 56 texture features. ctHPV16DNA levels were compared to texture features of primary tumors in OPSCC patients (Group A) or the largest primary or metastatic lymph node lesions in OPSCC and SCCUP patients (Group B) and to other PET parameters. Spearman rank correlation test and multiple regression analysis were used to confirm the associations between ctHPV16DNA levels and PET parameters. ctHPV16DNA levels moderately correlated with wbMTV, but not with SUVmax or MTV in Groups A and B. ctHPV16DNA levels exhibited a weak negative correlation with low gray-level zone emphasis in Groups A and B. Multiple regression analysis revealed that wbMTV and high gray-level zone emphasis were the significant factors for ctHPV16DNA levels in Group B. These results were not observed in Group A. This study demonstrated that ctHPV16DNA levels correlated with the whole-body tumor burden and tumor heterogeneity visualized on FDG PET-CT in patients with HPV-positive HNSCC.

Are MTV and TLG Accurate for Quantifying the Intensity of Brown Adipose Tissue Activation?

Recent research has suggested that one novel mechanism of action for anti-obesity medications is to stimulate the activation of brown adipose tissue (BAT). 18FDG PET/CT remains the gold standard for defining and quantifying BAT. SUVmax is the most often used quantification tool in clinical practice. However, this parameter does not reflect the entire BAT volume. As a potential method for precisely evaluating BAT, we have utilised metabolic tumour volume (MTV) and total lesion glycolysis (TLG) to answer the question: Are MTV and TLG accurate in quantifying the intensity of BAT activation? After analysing the total number of oncological 18F-FDG PET/CT scans between 2021-2023, we selected patients with active BAT. Based on the BAT SUVmax, the patients were divided into BAT-moderate activation (MA) vs. BAT-high activation (HA). Furthermore, we statistically analysed the accuracy of TLG and MTV in assessing BAT activation intensity. The results showed that both parameters increased their predictive value regarding BAT activation, and presented a significantly high sensitivity and specificity for the correct classification of BAT activation intensity. To conclude, these parameters could be important indicators with increased accuracy for classifying BAT expression, and could bring additional information about the volume of BAT to complement the limitations of the SUVmax.

Prognostic value of haematological parameters and [18F]FDG PET/CT metabolic parameters in head and neck cancer

AIM

To determine the usefulness of neutrophil/lymphocyte (N/L) and platelet/lymphocyte (P/L) ratios as well as quantitative [18F]FDG PET/CT parameters as prognostic factors for overall survival (OS), cancer-specific survival (CSS) and progression-free survival (PFS) in patients with head and neck squamous cell carcinoma (HyN).

MATERIAL AND METHODS

Sixty-six patients (56 men) diagnosed with HyN carcinoma were retrospectively assessed over an 8-year interval. Maximum SUV (SUVmax), metabolic tumour volume (MTV) and total lesion glycolysis (TLG) parameters were determined from the PET/CT study at diagnosis. After treatment with chemoradiotherapy, patient survival was assessed. The Cox regression model and the Kaplan-Meier method were used to analyse prognostic factors and survival curves.

RESULTS

Median follow-up was 50.4 months, with 39 recurrences-progressions and 39 deaths. In the univariate analysis, metabolic parameters, except SUVmax, were predictive factors for all three survivals and the two blood parameters were predictive for OS and EFS. TLG was the only predictive factor in the multivariate analysis. The three survival curves were significantly different for the metabolic parameters and the OS curve for the N/L ratio. Correlations were seen between N/L ratio, MTV and TLG. No correlations were demonstrated between P/L ratio and metabolic parameters.

CONCLUSION

The use of haematological and metabolic markers would allow to identify patients with a high risk of recurrences and por survival and to individualise treatment by applying more aggressive therapies.

Dual-tracer PET/CT protocol with [18F]FDG and [68Ga]Ga-FAPI-46 outperforms single-tracer PET/CT with [18F]FDG in different cancer types, resulting in larger functional and gross tumor volume

PURPOSE

Fibroblast activation protein (FAP) detected by positron-emission tomography (PET) using fibroblast activation protein inhibitor (FAPI) appears to be a promising target for cancer imaging, staging, and therapy, providing added value and strength as a complement to [18F]fluorodeoxyglucose (FDG) in cancer imaging. We recently introduced a combined single-session/dual-tracer protocol with [18F]FDG and [68Ga]Ga-FAPI for cancer imaging and staging. Malignant tissue visualization and target-to-background uptake ratios (TBRs) as well as functional tumor volume (FTV) and gross tumor volume (GTV) were assessed in the present study with single-tracer [18F]FDG PET/computed tomography (CT) and with dual-tracer [18F]FDG&[68Ga]Ga-FAPI-46 PET/CT.

METHODS

A total of 19 patients with head and neck and gastrointestinal cancers received initial [18F]FDG-PET/CT followed by dual-tracer PET/CT after additional injection of [68Ga]Ga-FAPI-46 during the same medical appointment (on average 13.9 ± 12.3 min after injection of [18F]FDG). Two readers visually compared detection rate of malignant tissue, TBR, FTV, and GTV for tumor and metastatic tissue in single- and dual-tracer PET/CT.

RESULTS

The diagnostic performance of dual-tracer compared to single-tracer PET/CT was equal in 13 patients and superior in 6 patients. The mean TBRs of tumors and metastases in dual-tracer PET/CTs were mostly higher compared to single-tracer PET/CT using maximal count rates (CRmax). GTV and FTV were significantly larger when measured on dual-tracer compared to single-tracer PET/CT.

CONCLUSION

Dual-tracer PET/CT with [18F]FDG and [68Ga]Ga-FAPI-46 showed better visualization due to a generally higher TBR and larger FTV and GTV compared to [18F]FDG-PET/CT in several tumor entities, suggesting that [68Ga]Ga-FAPI-46 provides added value in pretherapeutic staging.

Transthyretin amyloid cardiomyopathy disease burden quantified using 99mTc-pyrophosphate SPECT/CT: volumetric parameters versus SUVmax ratio at 1 and 3 hours

BACKGROUND

Various parameters derived from technetium-99m pyrophosphate (99mTc-PYP) single-photon emission computed tomography (SPECT) correlate with the severity of transthyretin amyloid cardiomyopathy (ATTR-CM). However, the optimal metrics and image acquisition timing required to quantify the disease burden remain uncertain.

METHODS AND RESULTS

We retrospectively evaluated 99mTc-PYP SPECT/CT images of 23 patients diagnosed with ATTR-CM using endomyocardial biopsies and/or gene tests. All patients were assessed by SPECT/CT 1 hour after 99mTc-PYP injection, and 13 of them were also assessed at 3 hours. We quantified 99mTc-PYP uptake using the volumetric parameters, cardiac PYP volume (CPV) and cardiac PYP activity (CPA). We also calculated the SUVmax ratios of myocardial SUVmax/blood pool SUVmax, myocardial SUVmax/bone SUVmax, and the SUVmax retention index. We assessed the correlations between uptake parameters and the four functional parameters associated with prognosis, namely left ventricular ejection fraction, global longitudinal strain, myocardial extracellular volume, and troponin T. CPV and CPA correlated more closely than the SUVmax ratios with the four prognostic factors. Significant correlations between volumetric parameters and prognostic factors were equivalent between 1 and 3 hours.

CONCLUSIONS

The disease burden of ATTR-CM was quantified more accurately by volumetric evaluation of 99mTc-PYP SPECT/CT than SUVmax ratios and the performance was equivalent between 1 and 3 hours.

Quantitative and clinical implications of the EARL2 versus EARL1 [18F]FDG PET-CT performance standards in head and neck squamous cell carcinoma

BACKGROUND

The EANM Research Ltd. (EARL) guidelines give recommendations for harmonization of [18F]FDG PET-CT image acquisition and reconstruction, aiming to ensure reproducibility of quantitative data between PET scanners. Recent technological advancements in PET-CT imaging resulted in an updated version of the EARL guidelines (EARL2). The aim of this study is to compare quantitative [18F]FDG uptake metrics of the primary tumor and lymph nodes in patients with head and neck squamous cell carcinoma (HNSCC) on EARL2 versus EARL1 reconstructed images and to describe clinical implications for nodal staging and treatment.

METHODS

Forty-nine consecutive patients with HNSCC were included. For all, both EARL1 and EARL2 images were reconstructed from a singular [18F]FDG PET-CT scan. Primary tumors and non-necrotic lymph nodes ≥ 5 mm were delineated on CT-scan. In the quantitative analysis, maximum standardized uptake values (SUVmax) and standardized uptake ratios (SURmax, i.e., SUVmax normalized to cervical spinal cord uptake) were calculated for all lesions on EARL1 and EARL2 reconstructions. Metabolic tumor volume (MTV) and total lesion glycolysis were compared between EARL1 and EARL2 using different segmentation methods (adaptive threshold; SUV2.5/3.5/4.5; SUR2.5/3.5/4.5; MAX40%/50%). In the qualitative analysis, each lymph node was scored independently by two nuclear medicine physicians on both EARL1 and EARL2 images on different occasions using a 4-point scale.

RESULTS

There was a significant increase in SUVmax (16.5%) and SURmax (9.6%) of primary tumor and lymph nodes on EARL2 versus EARL1 imaging (p < 0.001). The proportional difference of both SUVmax and SURmax between EARL2 and EARL1 decreased with increasing tumor volume (p < 0.001). Absolute differences in MTVs between both reconstructions were small (< 1.0 cm3), independent of the segmentation method. MTVs decreased on EARL2 using relative threshold methods (adaptive threshold; MAX40%/50%) and increased using static SUV or SUR thresholds. With visual scoring of lymph nodes 38% (11/29) of nodes with score 2 on EARL1 were upstaged to score 3 on EARL2, which resulted in an alteration of nodal stage in 18% (6/33) of the patients.

CONCLUSIONS

Using the EARL2 method for PET image reconstruction resulted in higher SUVmax and SURmax compared to EARL1, with nodal upstaging in a significant number of patients.

Contribution of Metabolic Parameters and Pericolic Fat Stranding on Preoperative 18F-FDG PET/CT in Predicting Post-operative Histopathology and Outcome in Colorectal Cancer

Purpose

We aimed to investigate the additional value of preoperative PET/CT and reveal relationships between metabolic parameters, pericolic fat stranding finding, postoperative histopathology, and overall survival in colorectal cancer (CRC).

Methods

CRC patients who underwent preoperative PET/CT between January 2017-December 2021 were analyzed. Lymph nodes, organ metastases, and metabolic parameters were evaluated from PET/CT. The pericolic fat stranding was evaluated from CT component. Relationships between these factors and postoperative histopathological findings were statistically analyzed. Survival analyses were performed.

Results

Ninety-one patients (59 males, 32 females) were included in the study. All tumors showed high FDG uptake (mean SUVmax 19.5 ± 9.9). SUVmax of the tumor differed significantly at T3 and T4 stages (p = 0.041). A significant correlation was found between MTV, TLG values and the differentiation degree (p = 0.005, 0.003, respectively). PET/CT predicted the N stage with a high accuracy rate (80%). PET/CT found additional metastases that changed treatment decisions in one-third of patients. A relationship was found between tumor length, surgical margin, lymphovascular invasion and pericolic fat stranding. In multivariate analysis, differentiation degree (HR = 26.1, 95%CI 1.672-408.467), MTV (HR = 0.3, 95%CI 0.071-0.841), TLG (HR = 3.5, 95%CI 1.065-11.193), and lymphovascular invasion (HR = 0.2, 95%CI 0.026-0.853, p = 0.033) were independent factors affecting overall survival.

Conclusion

Preoperative PET/CT contributes to CRC management by detecting additional metastases as well as predicting prognosis and postoperative findings such as T stage, N stage and tumor differentiation. The SUVmax may differentiate between T3 and T4 tumor. Reporting of pericolic fat stranding may contribute to the estimation of lymphatic invasion and positive surgical margin.

Circulating Tumor DNA in Head and Neck Squamous Cell Carcinoma: Association with Metabolic Tumor Burden Determined with FDG-PET/CT

BACKGROUND

The detection of circulating tumor DNA (ctDNA) with next-generation sequencing (NGS) in venous blood is a promising tool for the genomic profiling of head and neck squamous cell carcinoma (HNSCC). The association between ctDNA findings and metabolic tumor burden detected with FDG-PET/CT imaging is of particular interest for developing prognostic and predictive algorithms in HNSCC.

METHODS

Twenty-six prospectively enrolled HNSCC patients were eligible for further analysis. All patients underwent tumor tissue and venous liquid biopsy sampling and FDG-PET/CT before definitive oncologic treatment. An NGS-based commercial panel was used for a genomic analysis of the samples.

RESULTS

Maximum variant allele frequency (VAF) in blood correlated positively with whole-body (WB) metabolic tumor volume (MTV) and total lesion glycolysis (TLG) (r = 0.510, p = 0.008 and r = 0.584, p = 0.002, respectively). A positive liquid biopsy was associated with high WB-TLG using VAF ≥ 1.00% or ≥5.00% as a cut-off value (p = 0.006 or p = 0.003, respectively). Additionally, ctDNA detection was associated with WB-TLG when only concordant variants detected in both ctDNA and tissue samples were considered.

CONCLUSIONS

A high metabolic tumor burden based on FDG imaging is associated with a positive liquid biopsy and high maximum VAF. Our findings suggest a complementary role of metabolic and genomic signatures in the pre-treatment evaluation of HNSCC.

Development and External Validation of 18F-FDG PET-Based Radiomic Model for Predicting Pathologic Complete Response after Neoadjuvant Chemotherapy in Breast Cancer

The aim of our retrospective study is to develop and externally validate an 18F-FDG PET-derived radiomics model for predicting pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) in breast cancer patients. A total of 87 breast cancer patients underwent curative surgery after NAC at Soonchunhyang University Seoul Hospital and were randomly assigned to a training cohort and an internal validation cohort. Radiomic features were extracted from pretreatment PET images. A radiomic-score model was generated using the LASSO method. A combination model incorporating significant clinical variables was constructed. These models were externally validated in a separate cohort of 28 patients from Soonchunhyang University Buscheon Hospital. The model performances were assessed using area under the receiver operating characteristic (AUC). Seven radiomic features were selected to calculate the radiomic-score. Among clinical variables, human epidermal growth factor receptor 2 status was an independent predictor of pCR. The radiomic-score model achieved good discriminability, with AUCs of 0.963, 0.731, and 0.729 for the training, internal validation, and external validation cohorts, respectively. The combination model showed improved predictive performance compared to the radiomic-score model alone, with AUCs of 0.993, 0.772, and 0.906 in three cohorts, respectively. The 18F-FDG PET-derived radiomic-based model is useful for predicting pCR after NAC in breast cancer.

Early prediction of treatment outcome for lenvatinib using 18F-FDG PET/CT in patients with unresectable or advanced thyroid carcinoma refractory to radioiodine treatment: a prospective, multicentre, non-randomised study

BACKGROUND

Lenvatinib is widely used to treat unresectable and advanced thyroid carcinomas. We aimed to determine whether ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) performed 1 week after lenvatinib treatment initiation could predict treatment outcomes.

RESULTS

This was a prospective, nonrandomised, multicentre study. Patients with pathologically confirmed differentiated thyroid carcinoma (DTC) and lesions refractory to radioiodine treatment were eligible for inclusion. Patients were treated with 24 mg lenvatinib as the initial dose and underwent PET/CT examination 1 week after treatment initiation. Contrast-enhanced CT was scheduled at least 4 weeks later as the gold standard for evaluation. The primary endpoint was to evaluate the discrimination power of maximum standardised uptake value (SUVmax) obtained by PET/CT compared to that obtained by contrast-enhanced CT. Evaluation was performed using the area under the receiver operating characteristic (ROC-AUC) curve. Twenty-one patients were included in this analysis. Receiver operating characteristic (ROC) curve analysis yielded an AUC of 0.714 for SUVmax after 1 week of lenvatinib treatment. The best cut-off value for the treatment response for SUVmax was 15.211. The sensitivity and specificity of this cut-off value were 0.583 and 0.857, respectively. The median progression-free survival was 26.3 months in patients with an under-cut-off value and 19.7 months in patients with an over-cut-off value (P = 0.078).

CONCLUSIONS

The therapeutic effects of lenvatinib were detected earlier than those of CT because of decreased FDG uptake on PET/CT. PET/CT examination 1 week after the initiation of lenvatinib treatment may predict treatment outcomes in patients with DTC.

TRIAL REGISTRATION

This trial was registered in the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (number UMIN000022592) on 6 June, 2016.

Prognostic value of initial [ 18 F]FDG PET/computed tomography volumetric and texture analysis-based parameters in patients with head and neck squamous cell carcinoma

AIM OF WORK

To determine the predictive value of initial [ 18 F]FDG PET/computed tomography (CT) volumetric and radiomics-derived analyses in patients with head and neck squamous cell carcinoma (HNSCC).

METHODS

Forty-six adult patients had pathologically proven HNSCC and underwent pretherapy [ 18 F]FDG PET/CT were enrolled. Semi-quantitative PET-derived volumetric [(maximum standardized uptake value (SUVmax) and mean SUV (SUVmean), total lesion glycolysis (TLG) and metabolic tumor volume (MTV)] and radiomics analyses using LIFEx 6.73.3 software were performed.

RESULTS

In the current study group, the receiver operating characteristic curve marked a cutoff point of 21.105 for primary MTV with area under the curve (AUC) of 0.727, sensitivity of 62.5%, and specificity of 86.8% ( P value 0.041) to distinguish responders from non-responders, while no statistically significant primary SUVmean or max or primary TLG cut off points could be determined. It also marked the cutoff point for survival prediction of 10.845 for primary MTV with AUC 0.728, sensitivity of 80%, and specificity of 77.8% ( P value 0.026). A test of the synergistic performance of PET-derived volumetric and textural features significant parameters was conducted in an attempt to develop the most accurate and stable prediction model. Therefore, multivariate logistic regression analysis was performed to detect independent predictors of mortality. With a high specificity of 97.1% and an overall accuracy of 89.1%, the combination of primary tumor MTV and the textural feature gray-level co-occurrence matrix correlation provided the most accurate prediction of mortality ( P value < 0.001).

CONCLUSION

Textural feature indices are a noninvasive method for capturing intra-tumoral heterogeneity. In our study, a PET-derived prediction model was successfully generated with high specificity and accuracy.

Low TLR and PSMA-TV predict biochemical response to abiraterone acetate in metastatic prostate cancer patients developing castration resistance after chemohormonal therapy at hormone-sensitive stage

OBJECTIVE

To explore whether 68Ga-PSMA-11 PET/CT-derived parameters could predict biochemical response to abiraterone acetate (AA) treatment and prognosis in metastatic prostate cancer patients developing castration resistance after chemohormonal therapy at hormone-sensitive stage.

METHODS

The clinicopathologic data of 106 mCRPC cases receiving AA treatment were retrospectively analyzed. Logistic regression analysis was used to determine the independent predictors of biochemical response to AA treatment. Cox analyses were applied to investigate the independent prognostic factors for time to biochemical progression (TTBP) and radiological progression-free survival (rPFS). Survival analysis and ROC curve were also used.

RESULTS

Multivariable Logistic analysis demonstrated that prior ADT duration ≥ 12 months, low prostate specific membrane antigen receptor-expressing tumor volume (PSMA-TV), low tumor to liver ratio (TLR) were independent predictors of biochemical response to AA treatment. Multivariate Cox analysis demonstrated that low PSMA-TV and low TLR were independent prognostic factors of longer TTBP and rPFS. The TTBP and rPFS of patients with higher PSMA-TV or TLR were significantly decreased compared with that of patients with lower PSMA-TV and TLR. The area under ROC curve (AUC) of combining ADT duration, PSMA-TV and TLR was 0.82 for predicting biochemical response to AA, which was significantly increased compared with that of other 68Ga-PSMA-11 PET/CT-derived parameters alone.

CONCLUSIONS

Low PSMA-TV, low TLR were vital independent predictors of biochemical response to AA treatment and were associated with preferable prognosis in mCRPC patients. Combining ADT duration, PSMA-TV and TLR performed well in distinguishing AA responders from non-responders in mCRPC patients.

The Prognostic and Diagnostic Value of [18F]FDG PET/CT in Untreated Laryngeal Carcinoma

This study aims to determine the diagnostic accuracy of staging PET/CT and neck MRI in patients with laryngeal carcinoma and to assess the value of PET/CT in predicting progression-free survival (PFS) and overall survival (OS). Sixty-eight patients who had both modalities performed before treatment between 2014 and 2021 were included in this study. The sensitivity and specificity of PET/CT and MRI were evaluated. PET/CT had 93.8% sensitivity, 58.3% specificity, and 75% accuracy for nodal metastasis, whereas MRI had 68.8%, 61.1%, and 64.7% accuracy, respectively. At a median follow-up of 51 months, 23 patients had developed disease progression and 17 patients had died. Univariate-survival analysis revealed all utilized PET parameters as significant prognostic factors for OS and PFS (p-value < 0.03 each). In multivariate analysis, metabolic-tumor volume (MTV) and total lesion glycolysis (TLG) predicted better PFS (p-value < 0.05 each). In conclusion, PET/CT improves the accuracy of nodal staging in laryngeal carcinoma over neck MRI and adds to the prognostication of survival outcomes through the use of several PET metrics.

Prognostic and predictive values of baseline and mid-treatment FDG-PET in oropharyngeal carcinoma treated with primary definitive (chemo)radiation and impact of HPV status: review of current literature and emerging roles

BACKGROUND AND PURPOSE

This study provides a review of the literature assessing whether semiquantitative PET parameters acquired at baseline and/or during definitive (chemo)radiotherapy ("prePET" and "iPET") can predict survival outcomes in patients with oropharyngeal squamous cell carcinoma (OPC), and the impact of human papilloma virus (HPV) status.

MATERIAL AND METHODS

A literature search was carried out using PubMed and Embase between 2001 to 2021 in accordance with PRISMA.

RESULTS

The analysis included 22 FDG-PET/CT studies^1-22, 19 pre-PET and 3 both pre-PET and iPET^14,18,20,. The analysis involved 2646 patients, of which 1483 are HPV-positive (17 studies: 10 mixed and 7 HPV-positive only), 589 are HPV-negative, and 574 have unknown HPV status. Eighteen studies found significant correlations of survival outcomes with pre-PET parameters, most commonly primary or "Total" (combined primary and nodal) metabolic tumour volume and/or total lesional glycolysis. Two studies could not establish significant correlations and both employed SUVmax only. Two studies also could not establish significant correlations when taking into account of the HPV-positive population only. Because of the heterogeneity and lack of standardized methodology, no conclusions on optimal cut-off values can be drawn. Ten studies specifically evaluated HPV-positive patients: five showed positive correlation of pre-PET parameters and survival outcomes, but four of these studies did not include advanced T or N staging in multivariate analysis^1,6,15,22, and two studies only showed positive correlations after excluding high risk patients with smoking history⁷ or adverse CT features²². Two studies found that prePET parameters predicted treatment outcomes only in HPV-negative but not HPV-positive patients^10,16. Two studies found that iPET parameters could predict outcomes in HPV-positive patients but not prePET parameters^14,18.

CONCLUSION

The current literature supports high pre-treatment metabolic burden prior to definitive (chemo)radiotherapy can predict poor treatment outcomes for HPV-negative OPC patients. Evidence is conflicting and currently does not support correlation in HPV-positive patients.

Prognostic value of lymphovascular space invasion in stage IA to IIB cervical cancer: A meta-analysis

BACKGROUND

Lymphovascular space invasion (LVSI) is a prognostic factor in the existing TNM classification system. The present meta-analysis assessed the role of LVSI in predicting the prognosis of stage IA to IIB cervical cancer (CC).

MATERIALS AND METHODS

PubMed, EMBASE, and Cochrane Library electronic databases were searched to determine relevant articles published in the English language. Our search deadline was May 2022. Critical Appraisal of Prognostic Studies was used to assess the quality for each article. Pooled hazard ratios (HRs) were used to evaluate the performance of LVSI in prognosis prediction.

RESULTS

We enrolled 8 studies involving 25,352 patients published after 2010. Thus, high LVSI was an unfavorable factor in predicting overall survival (HR, 2.08; 95% confidence interval, 1.63-2.66; P = .006) and disease-free survival (HR, 2.20; 95% confidence interval, 1.79-2.70; P = .000) for patients with CC. However, the disease-free survival and overall survival were significantly different on univariate analysis based on the subgroup analysis stratified by analysis method, but no obvious heterogeneity was found across diverse articles.

CONCLUSIONS

The present study showed that LVSI predicts the poor prognostic outcome of stage IA to IIB CC. However, well-designed clinical articles should further assess the independent prognosis prediction performance of LVSI in CC.

Prediction of outcomes in patients with local recurrent nasopharyngeal carcinoma: development and validation of a four-factor prognostic model integrating baseline characteristics and [18F]FDG PET/CT parameters

OBJECTIVES

To investigate the prognostic value of [¹⁸F]FDG PET/CT parameters in local recurrent nasopharyngeal carcinoma (lrNPC) and establish a prognostic tool for lrNPC patients based on these [¹⁸F]FDG PET/CT parameters.

METHODS

A total of 358 lrNPC patients seen from 2010 to 2019 at Sun Yat-sen University Cancer Center with complete baseline characteristics and [¹⁸F]FDG PET/CT data were retrospectively analyzed. Maximal standardized uptake value (SUVmax), SUVmean, SUVpeak, metabolic tumor volume (MTV), total lesion glycolysis (TLG), and heterogeneity index (HI) for recurrent nasopharynx tumors were included. Cox regression analysis was performed to select candidate variables. Subsequently, a nomogram for predicting overall survival (OS) for lrNPC patients was developed and internally validated.

RESULTS

Multivariate Cox analysis results suggested that age ≥ 47 years (hazard ratio (HR), 1.62 (1.18-2.24); p = 0.003)，with smoking history (HR, 1.41 (1.01-1.98); p = 0.046), recurrent T stage {[rT3 vs rT1/2: HR, 1.81 (1.04-3.12); p = 0.037]; [rT4 vs rT1/2: HR, 2.46 (1.32-4.60); p = 0.005]}, and TLG {[37.1-184.3 vs ≤ 37.1: HR, 2.26 (1.49-3.42); p < 0.001]; [>184.3 vs ≤ 37.1: HR, 4.31 (2.50-7.43); p < 0.001]) were independent predictors of OS. A 4-factor nomogram was generated to stratify patients into 3 risk groups. This novel model showed good discrimination with a high C-index (0.752, 95%CI: 0.714-0.790). In addition, the calibration curves showed good agreement between the predicted probabilities and actual observations and decision curve analysis (DCA) suggested that the nomogram was useful for clinical decision-making.

CONCLUSIONS

Our study confirmed that [¹⁸F]FDG PET/CT parameters were valuable in predicting OS and PFS for lrNPC patients. The 4-factor prognostic model combing baseline patient characteristics with [¹⁸F]FDG PET/CT parameters for lrNPC patients had good discrimination, agreement, and clinical application potential.

KEY POINTS

• [¹⁸F]FDG PET/CT parameters were valuable in predicting OS and PFS for lrNPC patients. • The novel 4-factor nomogram for lrNPC patients had good discrimination, agreement, and potential for clinical application.

Technologist-Based Implementation of Total Metabolic Tumor Volume into Clinical Practice

Metabolic tumor volume (MTV) is defined as the total metabolically active tumor volume seen on ¹⁸F-FDG PET/CT examinations. Calculating MTV is often time-consuming, requiring a high degree of manual input. In this study, the MTV calculations of a board-certified nuclear radiologist were compared with those of 2 nuclear medicine technologists. As part of the technologists' educational program, after their classroom time they were trained by the radiologist for 30 min. The technologists calculated MTV within 7.5% of the radiologist's calculations in a set of patients who had diffuse large B-cell lymphoma and were undergoing initial staging ¹⁸F-FDG PET/CT. These findings suggest that nuclear medicine technologists may help accelerate implementation of MTV into clinical practice with favorable accuracy, possibly as an initial step followed by validation by the interpreting physician. The aim of this study was to explore whether efficiency is improved by integrating nuclear medicine technologists into a semiautomated workflow to calculate total MTV.

18F-Fluorodeoxyglucose Positron Emission Tomography Parameters can Predict Long-Term Outcome Following Trimodality Treatment for Oesophageal Cancer

AIMS

¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸FDG-PET/CT) is routinely used for the pre-treatment staging of oesophageal or gastro-oesophageal junction cancers (EGEJC). The aim of this study was to identify objective ¹⁸FDG-PET/CT-derived parameters that can aid in predicting the patterns of recurrence and prognostication in patients with EGEJC.

PATIENTS AND METHODS

EGEJC patients referred for consideration of preoperative chemoradiation therapy were identified and clinicopathological data were collected. ¹⁸FDG-PET/CT imaging data were reviewed and correlated with treatment outcomes. Maximum standardised uptake value (SUV_max), metabolic tumour volume (MTV) and total lesion glycolysis were assessed and association with recurrence-free survival (RFS), locoregional recurrence-free survival (LR-RFS), oesophageal cancer-specific survival (ECSS) and overall survival were evaluated using receiver operating characteristic curves, as well as Cox regression and Kaplan-Meier models.

RESULTS

In total, 191 EGEJC patients completed trimodality treatment and 164 with ¹⁸FDG-PET/CT data were included in this analysis. At the time of analysis, 15 (9.1%), 70 (42.7%) and two (1.2%) patients were noted to have locoregional, distant and both locoregional and distant metastases, respectively. The median RFS was 30 months (9.6-50.4) and the 5-year RFS was 31.1%. The 5-year overall survival and ECSS were both noted to be 34.8%. Pre-treatment MTV₂₅ > 28.5 cm³ (P = 0.029), MTV₄₀ > 12.4 cm³ (P = 0.018) and MTV₅₀ > 10.2 cm³ (P = 0.005) predicted for worse LR-RFS, ECSS and overall survival for MTV definition of voxels ≥25%, 40% and 50% of SUV_max.

CONCLUSION

¹⁸FDG-PET/CT parameters MTV and total lesion glycolysis are useful prognostic tools to predict for LR-RFS, ECSS and overall survival in EGEJC. MTV had the highest accuracy in predicting clinical outcomes. The volume cut-off points we identified for different MTV thresholds predicted outcomes with significant accuracy and may potentially be used for decision making in clinical practice.

Metabolic parameters of [18F]FDG PET-CT before and after radiotherapy may predict survival and recurrence in cervical cancer

BACKGROUND

Cervical cancer is the fourth most common female malignancy. [¹⁸F]-fluorodeoxyglucose (FDG) positron emission tomography with computed tomography (PET-CT) is routinely performed in patients with locally advanced cervical cancer for staging and treatment response evaluation. With this retrospective, observational cohort study, we wanted to investigate the prognostic value of the maximum standardised uptake value (SUVmax) and the volumetric parameters of metabolic tumour volume (MTV) and total lesion glycolysis (TLG) before and after treatment in women with cervical cancer, with overall survival (OS) and recurrence as outcome measures.

METHODS

Women with cervical cancer referred for curative radiotherapy and who underwent two PET-CT scans (before treatment and approximately 7 months post-treatment) were included. SUVmax, MTV and TLG were measured at baseline and post-treatment on the primary tumour, pelvic and distant lymph node metastases, distant organ metastases, and on total tumour burden. The PET parameters were associated with OS by Cox regression and recurrence by multivariable logistic regression. Kaplan-Meier curves and C-index were used to visualise the prognostic potential of the different measures.

RESULTS

A total of 133 patients were included. At the primary tumour level and on total tumour burden, age- and clinical-stage adjusted analyses showed a significant association between PET parameters and OS and recurrence when measured post-treatment. At baseline (pre-treatment), MTV and TLG were associated with OS and recurrence, whereas SUVmax was not. C-index from adjusted Cox models on total tumour burden showed higher values for the post-treatment PET compared to baseline. Kaplan-Meier curves demonstrated a greater prognostic potential for MTV and TLG compared to SUVmax, both at baseline and post-treatment.

CONCLUSIONS

The FDG PET-CT-derived parameters SUVmax, MTV, and TLG measured post-treatment can predict OS and recurrence in cervical cancer. Parameters measured before treatment had overall lower prognostic potential, and only MTV and TLG showed significant association to OS and recurrence.

[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.

FDG-PET/CT in the Monitoring of Lymphoma Immunotherapy Response: Current Status and Future Prospects

Cancer immunotherapy has been extensively investigated in lymphoma over the last three decades. This new treatment modality is now established as a way to manage and maintain several stages and subtypes of lymphoma. The establishment of this novel therapy has necessitated the development of new imaging response criteria to evaluate and follow up with cancer patients. Several FDG PET/CT-based response criteria have emerged to address and encompass the various most commonly observed response patterns. Many of the proposed response criteria are currently being used to evaluate and predict responses. The purpose of this review is to address the efficacy and side effects of cancer immunotherapy and to correlate this with the proposed criteria and relevant patterns of FDG PET/CT in lymphoma immunotherapy as applicable. The latest updates and future prospects in lymphoma immunotherapy, as well as PET/CT potentials, will be discussed.

Radiogenomic markers enable risk stratification and inference of mutational pathway states in head and neck cancer

PURPOSE

Head and neck squamous cell carcinomas (HNSCCs) are a molecularly, histologically, and clinically heterogeneous set of tumors originating from the mucosal epithelium of the oral cavity, pharynx, and larynx. This heterogeneous nature of HNSCC is one of the main contributing factors to the lack of prognostic markers for personalized treatment. The aim of this study was to develop and identify multi-omics markers capable of improved risk stratification in this highly heterogeneous patient population.

METHODS

In this retrospective study, we approached this issue by establishing radiogenomics markers to identify high-risk individuals in a cohort of 127 HNSCC patients. Hybrid in vivo imaging and whole-exome sequencing were employed to identify quantitative imaging markers as well as genetic markers on pathway-level prognostic in HNSCC. We investigated the deductibility of the prognostic genetic markers using anatomical and metabolic imaging using positron emission tomography combined with computed tomography. Moreover, we used statistical and machine learning modeling to investigate whether a multi-omics approach can be used to derive prognostic markers for HNSCC.

RESULTS

Radiogenomic analysis revealed a significant influence of genetic pathway alterations on imaging markers. A highly prognostic radiogenomic marker based on cellular senescence was identified. Furthermore, the radiogenomic biomarkers designed in this study vastly outperformed the prognostic value of markers derived from genetics and imaging alone.

CONCLUSION

Using the identified markers, a clinically meaningful stratification of patients is possible, guiding the identification of high-risk patients and potentially aiding in the development of effective targeted therapies.

Prospective Investigation of 18FDG-PET/MRI with Intravoxel Incoherent Motion Diffusion-Weighted Imaging to Assess Survival in Patients with Oropharyngeal or Hypopharyngeal Carcinoma

To prospectively investigate the prognostic value of 18F-FDG PET/MRI in patients with oropharyngeal or hypopharyngeal squamous cell carcinomas (OHSCC) treated by chemoradiotherapy. The study cohort consisted of patients with OHSCC who had undergone integrated PET/MRI prior to chemoradiotherapy or radiotherapy. Imaging parameters derived from intravoxel incoherent motion (IVIM), dynamic contrast-enhanced MRI (DCE-MRI), and 18F-FDG PET were analyzed in relation to overall survival (OS) and recurrence-free survival (RFS). In multivariable analysis, T classification (p < 0.001), metabolic tumor volume (p = 0.013), and pseudo-diffusion coefficient (p = 0.008) were identified as independent risk factors for OS. The volume transfer rate constant (p = 0.015), initial area under the curve (p = 0.043), T classification (p = 0.018), and N classification (p = 0.018) were significant predictors for RFS. The Harrell’s c-indices of OS and RFS obtained from prognostic models incorporating clinical and PET/MRI predictors were significantly higher than those derived from the traditional TNM staging system (p = 0.001). The combination of clinical risk factors with functional parameters derived from IVIM and DCE-MRI plus metabolic PET parameters derived from 18F-FDG PET in integrated PET/MRI outperformed the information provided by traditional TNM staging in predicting the survival of patients with OHSCC.

Risk stratification of endometrial cancer and lymph node metastases prediction using 18F-FDG PET/CT: role of metabolic tumor volume and total lesion glycolysis

Background

Endometrial cancer is the commonest gynecologic malignancy. Pelvic lymph node metastasis is considered one of its most important prognostic factors. Surgery is considered the most important and effective treatment, still there is controversy about indication and necessity of pelvic lymph node dissection. 18F-fluorodeoxyglucose positron emission tomography/computed tomography is investigated in his study to evaluate its value in preoperative detection of lymph node metastases and risk stratification of endometrial cancer.

Results

Reviewing the records of 33 women with endometrial cancer, all 18F-FDG PET/CT studied indices, SUVmax, SUVmean, MTV and TLG, mean difference was statistically significant in all the studied risk categories (tumor grade, Myometrial invasion, lymphovascular space invasion, tumor stage, and risk stratification). SUVmax and TLG showed highest area under the curve for detection of Myometrial invasion > 50% (AUC = 0.911) with cut-off value of SUVmax > 14.55 showing 88.89% sensitivity and 86.67% specificity, and TLG > 192.653 having 88.89% sensitivity and 80% specificity. TLG showed highest AUC (0.889 and 0.921) for detection of LVSI and LNMs with 100% sensitivity and 66.67% specificity for cut-off value > 179.374 and 88.89% sensitivity and 83.33% specificity for cut-off value > 249.366, respectively. Concerning risk stratification of EC, SUVmax and TLG showed highest AUC (0.839) with cut-off value > 14.55 showing 77.27% sensitivity and 90.91% specificity, and > 192.653 having 77.27% sensitivity and 81.82% specificity, respectively.

Conclusion

The results of this study suggest that 18F-FDG PET/CT is a very valuable tool for prediction of lymph node metastases and risk stratification in endometrial cancer patients. Applying TLG cutoff values increases the accuracy and preoperative diagnosis of lymph node metastases which aids in sparing women with low-risk early stage EC unnecessary surgical risk and morbidity of lymphadenectomy.

Prognostic value of lymph node ratio in cervical cancer: A meta-analysis

BACKGROUND

The role of the lymph node ratio (LNR) in the existing tumor node metastasis classification system should be verified as one of the prognosis prediction factors. This work evaluated LNR's performance in predicting cervical cancer (CC) prognosis through a meta-analysis.

METHOD

Related studies were retrieved from the Cochrane Library, EMBASE, and PubMed databases. The language was restricted to English. The combined hazard ratios (HRs) were utilized to analyze the prognostic value of LNR.

RESULTS

Our study included 8 articles with 3325 subjects published after 2015. Based on our analysis, high LNR was the adverse prognostic factor for overall survival (OS, HR = 1.45; 95% CI = 1.23-1.73; P = .238) and disease-free survival (DFS, HR = 2.69; 95% CI = 1.98-3.66; P = .597) among the CC cases. Furthermore, as revealed by subgroup analysis, in CC patients, median LNR of about 0.0625 and 0.066 served as the prominent risk factor for DFS and OS.

CONCLUSIONS

The current work illustrates that elevated LNR is related to the dismal prognosis of CC. More well-designed clinical studies are warranted for assessing whether LNR is a factor independently predicting the prognosis of CC.

Prognostic value of MTV and TLG of 18 F-FDG PET in patients with head and neck squamous cell carcinoma: A meta-analysis

BACKGROUND

The current systematic review and meta-analysis explored the value of metabolic tumor volume (MTV) as well as total lesion glycolysis (TLG) in predicting the prognosis of head and neck squamous cell carcinoma (HNSCC) using 18 F-FDG PET parameters.

METHODS

This work identified relevant studies in the English language by searching several electronic databases, like Cochrane Library, EMBASE, and PubMed. In addition, pooled hazard ratios (HRs) were also calculated to analyze whether MTV and TLG were significant in predicting prognosis.

RESULTS

The present study included 15 primary studies involving HNSCC cases. As for the elevated TLG, it attained the pooled HR of 1.85 (95% confidence interval [CI], 1.16-2.94; P = .000; I2 = 78.3%) in predicting overall survival (OS), whereas that for elevated MTV was1.22 (95%CI, 1.09-1.36; P = .000; I2 = 82.4%). Besides, for elevated MTV, it attained the pooled HR of 1.34 (95%CI, 1.15-1.56, P = .000; I2 = 86.0%) in predicting disease-free survival (DFS); while the elevated TLG was related to DFS. Sensitivity analysis confirmed that our results are reliable. As for MTV, the ROC-stratified subgroups for DFS and multivariate analyses-stratified subgroups for OS showed statistically significant differences, with no obvious heterogeneities across different studies. For TLG, other methods-stratified subgroups for OS showed statistically significant differences, with no obvious heterogeneity across different studies.

CONCLUSION

This work indicated that PET/CT is of predictive significance across HNSCC cases. Although the included articles used different methods and recruited HNSCC cases with high clinical heterogeneity; however, our findings confirmed that an elevated MTV can predict the increased risk of side reactions or even death among HNSCC cases and that an elevated TLG can predict a higher death risk.

Metabolic parameters on baseline 18F-FDG PET/CT are potential predictive biomarkers for immunotherapy in patients with head and neck squamous cell carcinoma

Purpose

We evaluated baseline 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) metabolic parameters for predicting prognosis in patients with head and neck squamous cell carcinoma (HNSCC) who were receiving immune checkpoint inhibitors (ICIs). In addition, we also investigated the relationships between immunohistochemical (IHC) biomarkers and metabolic parameters.

Materials and methods

A total of 39 patients with HNSCC who underwent 18F-FDG PET/CT prior to ICI therapy between November 2015 and December 2020 were enrolled. PET parameters of tumor lesions included standardized uptake values, metabolic tumor volume (MTV), total lesion glycolysis (TLG), and spleen-to-liver ratio (SLR). Clinical variables, IHC markers, and derived neutrophil-to-lymphocyte ratio (dNLR) were also obtained. Analysis was performed using Cox proportional hazard model, Kaplan-Meier method with log-rank test, and Spearman's correlation.

Results

Total MTV (TMTV), total TLG (TTLG), and a combined parameter consisting of TMTV and dNLR were significant predictors for progression-free survival (PFS) in univariable analysis (TMTV, p = 0.018; TTLG, p = 0.027; combined parameter, p = 0.021). Above all, the combined parameter was an independent prognostic factor for PFS in multivariable analysis. The group with low TMTV and low dNLR had longer PFS than the group with high TMTV and high dNLR (p = 0.036). SLR was the only significant predictor for overall survival (p = 0.019). Additionally, there was a negative correlation between programmed cell death-ligand 1 expression (one of the IHC markers) and MTV in subgroup analysis.

Conclusion

PET parameters on baseline 18F-FDG PET/CT were predictive biomarkers for prognosis in patients with HNSCC undergoing ICI therapy. With dNLR, more accurate prognostic prediction could be possible.

Development of a Hybrid-Imaging-Based Prognostic Index for Metastasized-Melanoma Patients in Whole-Body 18F-FDG PET/CT and PET/MRI Data

Besides tremendous treatment success in advanced melanoma patients, the rapid development of oncologic treatment options comes with increasingly high costs and can cause severe life-threatening side effects. For this purpose, predictive baseline biomarkers are becoming increasingly important for risk stratification and personalized treatment planning. Thus, the aim of this pilot study was the development of a prognostic tool for the risk stratification of the treatment response and mortality based on PET/MRI and PET/CT, including a convolutional neural network (CNN) for metastasized-melanoma patients before systemic-treatment initiation. The evaluation was based on 37 patients (19 f, 62 ± 13 y/o) with unresectable metastasized melanomas who underwent whole-body 18F-FDG PET/MRI and PET/CT scans on the same day before the initiation of therapy with checkpoint inhibitors and/or BRAF/MEK inhibitors. The overall survival (OS), therapy response, metastatically involved organs, number of lesions, total lesion glycolysis, total metabolic tumor volume (TMTV), peak standardized uptake value (SULpeak), diameter (Dmlesion) and mean apparent diffusion coefficient (ADCmean) were assessed. For each marker, a Kaplan−Meier analysis and the statistical significance (Wilcoxon test, paired t-test and Bonferroni correction) were assessed. Patients were divided into high- and low-risk groups depending on the OS and treatment response. The CNN segmentation and prediction utilized multimodality imaging data for a complementary in-depth risk analysis per patient. The following parameters correlated with longer OS: a TMTV < 50 mL; no metastases in the brain, bone, liver, spleen or pleura; ≤4 affected organ regions; no metastases; a Dmlesion > 37 mm or SULpeak < 1.3; a range of the ADCmean < 600 mm2/s. However, none of the parameters correlated significantly with the stratification of the patients into the high- or low-risk groups. For the CNN, the sensitivity, specificity, PPV and accuracy were 92%, 96%, 92% and 95%, respectively. Imaging biomarkers such as the metastatic involvement of specific organs, a high tumor burden, the presence of at least one large lesion or a high range of intermetastatic diffusivity were negative predictors for the OS, but the identification of high-risk patients was not feasible with the handcrafted parameters. In contrast, the proposed CNN supplied risk stratification with high specificity and sensitivity.

Dynamic Characteristics and Predictive Capability of Tumor Voxel Dose-Response Assessed Using 18F-FDG PET/CT Imaging Feedback

Purpose

Tumor voxel dose–response matrix (DRM) can be quantified using feedback from serial FDG-PET/CT imaging acquired during radiotherapy. This study investigated the dynamic characteristics and the predictive capability of DRM.

Methods

FDG-PET/CT images were acquired before and weekly during standard chemoradiotherapy with the treatment dose 2 Gy × 35 from 31 head and neck cancer patients. For each patient, deformable image registration was performed between the pretreatment/baseline PET/CT image and each weekly PET/CT image. Tumor voxel DRM was derived using linear regression on the logarithm of the weekly standard uptake value (SUV) ratios for each tumor voxel, such as SUV measured at a dose level normalized to the baseline SUV₀. The dynamic characteristics were evaluated by comparing the DRM_i estimated using a single feedback image acquired at the ith treatment week (i = 1, 2, 3, or 4) to the DRM estimated using the last feedback image for each patient. The predictive capability of the DRM estimated using 1 or 2 feedback images was evaluated using the receiver operating characteristic test with respect to the treatment outcome of tumor local–regional control or failure.

Results

The mean ± SD of tumor voxel SUV measured at the pretreatment and the 1st, 2nd, 3rd, 4th, and last treatment weeks was 6.76 ± 3.69, 5.72 ± 3.43, 3.85 ± 2.22, 3.27 ± 2.25, 2.5 ± 1.79, and 2.23 ± 1.27, respectively. The deviations between the DRM_i estimated using the single feedback image obtained at the ith week and the last feedback image were 0.86 ± 4.87, −0.06 ± 0.3, −0.09 ± 0.17, and −0.09 ± 0.12 for DRM₁, DRM₂, DRM₃, and DRM₄, respectively. The predictive capability of DRM₃ and DRM₄ was significant (p < 0.001). The area under the curve (AUC) was increased with the increase in treatment dose level. The DRMs constructed using the single feedback image achieved an AUC of 0.86~1. The AUC was slightly improved to 0.94~1 for the DRMs estimated using 2 feedback images.

Conclusion

Tumor voxel metabolic activity measured using FDG-PET/CT fluctuated noticeably during the first 2 treatment weeks and obtained a stabilized reduction rate thereafter. Tumor voxel DRM constructed using a single FDG-PET/CT feedback image after the 2nd treatment week (>20 Gy) has a good predictive capability. The predictive capability improved continuously using a later feedback image and marginally improved when two feedback images were applied.

Is there an association between thyroid function tests and 18F FDG PET/CT parameters in untreated cancer patients?

Objectives: We aimed to investigate the association between the extent of disease, 18F FDG PET/CT parameters (SUVmax and the highest SUVmax) and thyroid function tests (TFT) (TSH, FT4, FT3, FT3/FT4 ratio, AntiTG, and AntiTPO) in untreated cancer patients. Material and Method: One hundred and seventy-nine patients who underwent FDG PET/CT for metabolic characterization and staging in our clinic between May 2020 and November 2020 were included in the study. Patients were divided into two groups as malignant and benign according to histopathology findings. Thyroid function tests were ordered from all patients at the time of PET/CT imaging. The association between the presence of local lymph node metastasis, distant metastases and thyroid function tests as well as the association between PET/CT parameters and thyroid function tests in benign and malignant groups were statistically analyzed. Results: Thyroid function tests did not exhibit a significant difference between patients with malignant and benign disease (p> 0.05). Univariate logistic regression analysis revealed that age, FT4 value, and the FT3/F4 ratio were significant parameters in predicting distant metastases. These parameters were also significant in predicting mortality. Multivariate logistic regression analysis showed that age was an independent prognostic factor predicting mortality. Conclusion: Thyroid function tests are not decisive in differentiating malignant and benign lesions. While no statistically significant correlation was observed between thyroid function tests and PET/CT parameters, univariate analyses revealed that especially FT4 and FT3/FT4 ratio were significant in predicting disease extent and mortality in malignant disease. Age was found to be an independent prognostic factor in predicting mortality.

Utility and limitations of metabolic parameters in head and neck cancer: finding a practical segmentation method

PURPOSE

Although metabolic tumor volume (MTV) and total lesion glycolysis (TLG) have shown good prognostic value in head and neck cancer (HNC), there are still many issues to resolve before their potential application in standard clinical practice. The purpose of this study was to compare the discrimination ability of two relevant segmentation methods in HNC and to evaluate the potential benefit of adding lymph nodes' metabolism (LNM) to the measurements.

METHODS

We retrospectively analyzed a recently published database of 62 patients with HNC treated with chemoradiotherapy. MTV and TLG were measured using an absolute threshold of SUV2.5. Comparison analysis with previously published background-level threshold (BLT) results was done through Concordance index (C-index) in eight prognostic models.

RESULTS

BLT obtained better C-index values in five out of the eight models. The addition of LNM improved C-index values in six of the prognostic models.

CONCLUSION

We found a potential benefit in adding LNM to the main tumor measurements, as well as in using a BLT for MTV segmentation compared to the most commonly used SUV2.5 threshold. Despite its limitations, this study suggests a practical and simple manner to use these parameters in standard clinical practice, aiming to help elaborate a general consensus.

18F-FDG-PET/CT can be used to predict distant metastasis in hypopharyngeal squamous cell carcinoma

Background

Hypopharyngeal squamous cell carcinoma (HPSCC) has a high rate of distant metastasis, resulting in poor prognosis. The role of the maximum standardized uptake value (SUVmax), which was assessed via pretreatment 18-fluorodeoxyglucose positron emission tomography (FDG-PET), and computed tomography (CT) was examined, for predicting distant metastasis and survival.

Methods

This study included 121 patients who underwent pretreatment FDG-PET/CT scanning and subsequent treatment for HPSCC. The SUVmax was measured via FDG-PET/CT. A receiver operating characteristic (ROC) curve analysis was used to determine whether the SUVmax was a predictor of distant metastasis and to select the best cutoff value. Univariate and multivariate Cox hazard regression analyses were used in identifying associations between the SUVmax and other clinicopathological factors with distant metastasis-free survival.

Results

Distant metastases were identified in 33 patients during the median follow-up of 24 months after treatment. The ROC curve analysis determined that SUVmax was predictive of distant metastasis and identified a SUVmax of 13.9 as the best potential cutoff value. The univariate analysis showed that T and N classification, clinical stage, and SUVmax were significantly related to distant metastasis. However, in multivariate analysis, an SUVmax ≥ 13.9 was the only independent predictor of distant metastasis. Patients with high SUVmax values displayed significantly shorter distant metastasis-free survival and overall survival.

Conclusions

SUVmax determined via pretreatment FDG-PET/CT is useful for predicting distant metastasis, distant metastasis-free survival, and overall survival in patients with HPSCC.

Graphical Abstract

Comparison of Volumetric Quantitative PET Parameters Before and After a CT-Based Elastic Deformation on Dual-Time 18FDG-PET/CT Images: A Feasibility Study in a Perspective of Radiotherapy Planning in Head and Neck Cancer

Background

The use of 18FDG-PET/CT for delineating a gross tumor volume (GTV, also called MTV metabolic tumor volume) in radiotherapy (RT) planning of head neck squamous cell carcinomas (HNSCC) is not included in current recommendations, although its interest for the radiotherapist is of evidence. Because pre-RT PET scans are rarely done simultaneously with dosimetry CT, the validation of a robust image registration tool and of a reproducible MTV delineation method is still required.

Objective

Our objective was to study a CT-based elastic registration method on dual-time pre-RT 18FDG-PET/CT images to assess the feasibility of PET-based RT planning in patients with HNSCC.

Methods

Dual-time 18FDG-PET/CT [whole-body examination (wbPET) + 1 dedicated step (headPET)] were selected to simulate a 2-times scenario of pre-RT PET images deformation on dosimetry CT. ER-headPET and RR-headPET images were, respectively, reconstructed after CT-to-CT rigid (RR) and elastic (ER) registrations of the headPET on the wbPET. The MTVs delineation was performed using two methods (40%SUVmax, PET-Edge). The percentage variations of several PET parameters (SUVmax, SUVmean, SUVpeak, MTV, TLG) were calculated between wbPET, ER-headPET, and RR-headPET. Correlation between MTV values was calculated (Deming linear regression). MTVs intersections were assessed by two indices (OF, DICE) and compared together (Wilcoxon test). Additional per-volume analysis was evaluated (Mann-Whitney test). Inter- and intra-observer reproducibilities were evaluated (ICC = intra-class coefficient).

Results

36 patients (30M/6F; median age = 65 y) were retrospectively included. The changes in SUVmax, SUVmean and SUVpeak values between ER-headPET and RR-headPET images were <5%. The variations in MTV values between ER-headPET and wbPET images were −6 and −3% with 40%SUVmax and PET Edge, respectively. Their correlations were excellent whatever the delineation method (R² > 0.99). The ER-headPET MTVs had significant higher mean OF and DICE with the wbPET MTVs, for both delineation methods (p ≤ 0.002); and also when lesions had a volume > 5cc (excellent OF = 0.80 with 40%SUVmax). The inter- and intra-observer reproducibilities for MTV delineation were excellent (ICC ≥ 0.8, close to 1 with PET-Edge).

Conclusion

Our study demonstrated no significant changes in MTV after an elastic deformation of pre-RT 18FDG-PET/CT images acquired in dual-time mode. This opens possibilities for HNSCC radiotherapy planning improvement by transferring GTV-PET on dosimetry CT.

Influences on PET Quantification and Interpretation

Various factors have been identified that influence quantitative accuracy and image interpretation in positron emission tomography (PET). Through the continuous introduction of new PET technology-both imaging hardware and reconstruction software-into clinical care, we now find ourselves in a transition period in which traditional and new technologies coexist. The effects on the clinical value of PET imaging and its interpretation in routine clinical practice require careful reevaluation. In this review, we provide a comprehensive summary of important factors influencing quantification and interpretation with a focus on recent developments in PET technology. Finally, we discuss the relationship between quantitative accuracy and subjective image interpretation.

Correlation between Tissue Cellularity and Metabolism Represented by Diffusion-Weighted Imaging (DWI) and 18F-FDG PET/MRI in Head and Neck Cancer (HNC)

Simple Summary

We report on the correlation between the diffusion-weighted imaging (DWI) and the metabolic volume parameters derived from a PET scan, to determine the correlation between these parameters and the tumor cellularity in head and neck primary tumors. Our findings implied that there was no correlation between the information derived from the DWI and the information derived from the FDG metabolic parameters. Thus, both imaging techniques might play a complementary role in HNC diagnosis and assessment. This is significant because the treatment plan of patients with HNC should be well evaluated by using all the available diagnosis techniques, for a better understanding of how the tumor will react.

Abstract

Background: This study aimed to assess the association of 18F-Fluorodeoxyglucose positron-emission-tomography (18F-FDG/PET) and DWI imaging parameters from a primary tumor and their correlations with clinicopathological factors. Methods: We retrospectively analyzed primary tumors in 71 patients with proven HNC. Primary tumor radiological parameters: DWI and FDG, as well as pathological characteristics were analyzed. Spearman correlation coefficient was used to assess the correlation between DWI and FDG parameters, ANOVA or Kruskal–Wallis, independent sample t-test, Mann–Whitney test, and multiple regression were performed on the clinicopathological features that may affect the 18F- FDG and apparent-diffusion coefficient (ADC) of the tumor. Results: No significant correlations were observed between DWI and any of the 18F-FDG parameters (p > 0.05). SUVmax correlated with N-stages (p = 0.023), TLG and MTV correlated with T-stages (p = 0.006 and p = 0.001), and ADC correlated with tumor grades (p = 0.05). SUVmax was able to differentiate between N+ and N− groups (p = 0.004). Conclusions: Our results revealed a non-significant correlation between the FDG-PET and ADC-MR parameters. FDG-PET-based glucose metabolic and DWI-MR-derived cellularity data may represent different biological aspects of HNC.

Prognostic value of maximum standard uptake value, metabolic tumour volume, and total lesion glycolysis of 18F-FDG PET/CT in patients with malignant pleural mesothelioma: a systematic review and meta-analysis

PURPOSE

Present work systematically reviewed relevant literature based on 18F-FDG PET parameters and conducted a meta-analysis to examine the prognostic value of maximal standard uptake value (SUVmax), total lesional glycolysis (TLG), and metabolic tumour volume (MTV) in the prognosis of malignant pleural mesothelioma (MPM).

METHODS

The relevant literature published in English were searched on PubMed, Cochrane Library, and EMBASE databases. We also evaluated the significance of SUVmax, TLG, and MTV in prognosis prediction using pooled hazard ratios (HRs).

RESULTS

The current study comprised 12 primary studies with a total of 1307 MPM cases. According to our results, the pooled HR (95% confidence interval [CI]) of increased SUVmax for overall survival (OS) was 1.30 (95% CI 1.13-1.49, P = 0.000), whereas the increased TLG was 1.81(95% CI 1.25-2.61, P = 0.089). The increased MTV was not significantly related to OS (1.14 [95% CI 0.87-1.50, P = 0.18]).However, study design-stratified subgroup analysis suggested that differences in OS of retrospective and prospective subgroups were statistically significant, and no significant heterogeneity among different studies was observed.

CONCLUSION

Based on the findings from the present work, PET/CT can significantly affect the prognosis prediction in MPM cases. Also, the increased SUVmax and TLG values predict an increased risk of mortality.