18F-fluorodeoxyglucose Positron Emission Tomography-computed Tomography Research Articles

Psoriasis. Definition and Classification of A Complex Entity

Psoriasis, a chronic inflammatory skin condition influenced by hereditary factors and immune system response, exhibits diverse clinical manifestations. While its global incidence is around 2%, prevalence varies across geographical regions and ethnicities. The most common form, psoriasis vulgaris, presents as red, itchy patches with silver-colored scales, predominantly affecting the trunk, limbs, and scalp. Other clinical subtypes include inverse psoriasis, guttate psoriasis, pustular psoriasis, and erythrodermic psoriasis, each with distinct features and impacts. Beyond skin manifestations, psoriasis is associated with various co-occurring medical conditions, including hyperlipidemia, hypertension, coronary artery disease, type 2 diabetes, and obesity. Psoriasis patients have an increased risk of cardiovascular disease, with severity correlating with the incidence of diabetes and cardiovascular events. Additionally, psoriatic arthritis affects around 40% of patients and is often accompanied by nail involvement. Recent studies utilizing imaging techniques like 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) and nuclear magnetic resonance spectroscopy have shed light on systemic inflammation and cardiovascular risk in psoriasis patients. Treatments targeting IL-23 and IL-17 have shown promising results, though long-term efficacy and drug survival remain areas of concern. Psoriasis profoundly impacts patients' quality of life, with psychological distress comparable to cancer and depression. However, treatment can significantly alleviate symptoms and improve overall well-being. Ongoing research aims to expand treatment options, particularly targeting novel molecular pathways. In conclusion, while significant progress has been made in understanding and treating psoriasis, challenges remain in optimizing therapy selection and long-term management. Further research is warranted to elucidate the complex genetic and immunological underpinnings of the disease and to enhance treatment outcomes for affected individuals

Diagnostic performance of a deep-learning model using 18F-FDG PET/CT for evaluating recurrence after radiation therapy in patients with lung cancer.

We developed a deep learning model for distinguishing radiation therapy (RT)-related changes and tumour recurrence in patients with lung cancer who underwent RT, and evaluated its performance. We retrospectively recruited 308 patients with lung cancer with RT-related changes observed on 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) performed after RT. Patients were labelled as positive or negative for tumour recurrence through histologic diagnosis or clinical follow-up after 18F-FDG PET/CT. A two-dimensional (2D) slice-based convolutional neural network (CNN) model was created with a total of 3329 slices as input, and performance was evaluated with five independent test sets. For the five independent test sets, the area under the curve (AUC) of the receiver operating characteristic curve, sensitivity, and specificity were in the range of 0.98-0.99, 95-98%, and 87-95%, respectively. The region determined by the model was confirmed as an actual recurred tumour through the explainable artificial intelligence (AI) using gradient-weighted class activation mapping (Grad-CAM). The 2D slice-based CNN model using 18F-FDG PET imaging was able to distinguish well between RT-related changes and tumour recurrence in patients with lung cancer.

Dual-tracer PET/CT in the management of hepatocellular carcinoma

Background & AimsCombined 18F-fluorodeoxyglucose (FDG) and 11C-acetate (dual-tracer) positron emission tomography-computed tomography (PET-CT) is being increasingly performed for the management of hepatocellular carcinoma (HCC), although its role is not well defined. Therefore, we evaluated its effectiveness in (i) staging, (ii) characterization of indeterminate lesions on conventional imaging, and (iii) detection of HCC in patients with unexplained elevations in serum alpha-fetoprotein (AFP) levels. MethodsWe retrospectively assessed 525 consecutive patients from three tertiary centers between 2014 and 2020. For staging, we recorded new lesion detection rates, changes in the Barcelona Clinic Liver Cancer (BCLC) classification, and treatment allocation due to dual-tracer PET-CT. To characterize indeterminate lesions and unexplained elevation of serum AFP levels, the sensitivity and specificity of dual-tracer PET-CT in diagnosing HCC were evaluated. A Multidisciplinary external review and a cost-benefit analysis of patients for metastatic screening were also performed. ResultsDual-tracer PET/CT identified new lesions in 14.3% of 273 staging patients, resulting in BCLC upstaging in 11.7% and treatment modifications in 7.7%. It upstaged 8.1% of 260 patients undergoing metastatic screening, with an estimated savings of US$495 per patient. It had a sensitivity and specificity of 80.7% (95% CI 71.2-88.6%) and 94.8% (95% CI 90.4-98.6%), respectively, for diagnosing HCC in 201 indeterminate lesions. It detected HCC in 45.1% of 51 patients with unexplained elevations in serum AFP concentrations. External review revealed substantial agreement between local and external image interpretation and patient assessment (n=273, κ=0.822; 95% CI 0.803-0.864). ConclusionsDual-tracer PET/CT provides additional value to conventional imaging in HCC patients by improving staging, confirming HCC diagnosis with high accuracy in patients with indeterminate lesions, and detecting HCC in patients with unexplained elevation of serum AFP.• Impact and implications• Dual-tracer PET-CT detected 12% more disease in HCC patients undergoing staging than CT or MRI, resulting in change in treatment in 8% of cases and a cost saving of US$495 per patient.• It is also able to accurately detect HCC in high-risk cases where CT or MRI are equivocal or normal.• Dual-tracer PET/CT provides additional value to conventional imaging in HCC patients by improving staging, confirming HCC diagnosis with high accuracy in patients with indeterminate lesions, and detecting HCC in patients with unexplained elevation of serum AFP.

Efficacy and safety of FDG-PET for determining target volume during intensity-modulated radiotherapy for head and neck cancer involving the oral level

PurposeTo determine the efficacy and safety of target volume determination by 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) for intensity-modulated radiation therapy (IMRT) for locally advanced head and neck squamous cell carcinoma (HNSCC) extending into the oral cavity or oropharynx.MethodsWe prospectively treated 10 consecutive consenting patients with HNSCC using IMRT, with target volumes determined by PET-CT. Gross tumor volume (GTV) and clinical target volume (CTV) at the oral level were determined by two radiation oncologists for CT, magnetic resonance imaging (MRI), and PET-CT. Differences in target volume (GTVPET, GTVCT, GTVMRI, CTVPET, CTVCT, and CTVMRI) for each modality and the interobserver variability of the target volume were evaluated using the Dice similarity coefficient and Hausdorff distance. Clinical outcomes, including acute adverse events (AEs) and local control were evaluated.ResultsThe mean GTV was smallest for GTVPET, followed by GTVCT and GTVMRI. There was a significant difference between GTVPET and GTVMRI, but not between the other two groups. The interobserver variability of target volume with PET-CT was significantly less than that with CT or MRI for GTV and tended to be less for CTV, but there was no significant difference in CTV between the modalities. Grade ≤ 3 acute dermatitis, mucositis, and dysphagia occurred in 55%, 88%, and 22% of patients, respectively, but no grade 4 AEs were observed. There was no local recurrence at the oral level after a median follow-up period of 37 months (range, 15–55 months).ConclusionsThe results suggest that the target volume determined by PET-CT could safely reduce GTV size and interobserver variability in patients with locally advanced HNSCC extending into the oral cavity or oropharynx undergoing IMRT.Trial registrationUMIN, UMIN000033007. Registered 16 jun 2018, https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000037631

The Contribution of 18F FDG PET-CT for the Investigation of Fever of Unknown Origin and Inflammation of Unknown Origin

BackgroundFever of unknown origin and inflammation of unknown origin are highly challenging diagnostic conditions. The current practice for evaluating patients is to conduct a positron emission tomography-computed tomography (PET-CT) scan as either a first- or a second-line modality. We aimed to assess the contributory effect of PET-CT to the diagnosis and compare it with the contributory effect of CT alone. MethodsWe performed a systematic review and meta-analysis. We included all cohorts that examined the contribution of PET-CT to the investigation of classical fever of unknown origin and inflammation of unknown origin. The primary outcome was the contribution of PET-CT to the final diagnosis. Secondary outcomes were sensitivity and specificity of PET-CT and CT scans, and contribution of a CT scan. We pooled the results of all studies and calculated the pooled contributory effect of PET-CT. ResultThirty-six studies (3516 patients) were included in the systematic review. The pooled contribution of PET-CT was 75.4%. The compiled sensitivity and specificity values for all studies were 85.9% and 59.5%, respectively. Five studies (405 patients) compared between the PET-CT component and the total body CT component. The pooled contribution of a CT scan was 68%. The summed sensitivity and specificity values of a CT scan for all studies were 63.1% and 84.4%, respectively. ConclusionsPET-CT has a contributory effect of 75% for the diagnosis of fever of unknown origin and inflammation of unknown origin. PET-CT had superior sensitivity and inferior specificity vs the CT scan.

Predicting epithelial ovarian cancer prognosis: correlation of posttreatment 18F-fluorodeoxyglucose positron emission tomography-computed tomography metabolic parameters, serum carbohydrate antigen, and human epididymis protein levels with overall survival.

Identifying reliable prognostic indicators can aid in improving patient care. The aim of this study was to establish the association of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) whole-body metabolic parameters, serum carbohydrate antigen 125 (CA125), and human epididymis protein 4 (HE4) with overall survival (OS) in patients with epithelial ovarian cancer (EOC) after surgery combined with platinum-based chemotherapy. From May 2014 to May 2019, a total of 79 patients with EOC who underwent posttreatment 18F-FDG PET/CT in the First Affiliated Hospital of Chongqing Medical University were included. Clinical data and laboratory indicators were obtained. The whole-body maximum standardized uptake value (WBSUVmax), whole-body metabolic tumor volume (WBMTV), and whole-body total lesion glycolysis (WBTLG) were measured and calculated on 18F-FDG PET/CT. The follow-up was conducted until February 2023, and the endpoint was death from any cause. Pearson correlation analysis, Kaplan-Meier, and Cox proportional regression were used in this study. The PET-positive (PET-P) patients had significantly decreased OS based on either Kaplan-Meier survival analysis (P<0.001) or univariate Cox regression analysis [hazard ratio (HR) =40.177, 95% confidence interval (CI): 2.690-600.134; P=0.007]. "Ln" is a logarithmic transformation with a base of "e" (natural logarithm). LnWBMTV, lnWBTLG, and therapy after PET were independent predictors of OS in a cohort of 63 PET-P patients. The difference in OS between groups sorted by the median WBMTV (4.16; P<0.001) and WBTLG (14.71; P<0.001) was statistically significant. There were statistically significant differences in CA125 and HE4 levels between patients in the PET-P and PET-negative (PET-N) groups (P<0.001). In the PET-P patient cohort, serum HE4 levels were substantially correlated with WBMTV and WBTLG. Kaplan-Meier survival analysis suggested a reduction in OS after treatment in patients with EOC positive for CA125, HE4, and PET (P<0.001). Post-PET/CT treatment strategy, WBMTV, and WBTLG demonstrated significant prognostic utility in predicting posttreatment OS in patients with EOC. Patients who tested positive for both tumor markers CA125 and HE4 and had a positive PET scan demonstrated a significantly poorer prognosis in terms of posttreatment OS.

Detection of Primary Hepatocellular Carcinoma on 18F-Fluorodeoxyglucose Positron Emission Tomography-computed Tomography.

Hepatocellular carcinoma (HCC), ranks as the third most prevalent malignancy contributing to cancer-related death on a global scale. Hepatocellular carcinoma is known to be the fifth most frequently diagnosed malignancy of the males while among females, it is ranked as the seventh most common malignancy. The study was conducted to detect the sensitivity of primary HCC using 18F-flourodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) scan. This prospective study was conducted to identify the primary HCC in a sample size of 51 patients, in whom FDG PET-CT scan was performed between May 2022 and December 2022. Among the cohort of 51 patients, primary HCC was detected on FDG PET-CT in 43 individuals representing true-positive cases. Conversely, FDG PET-CT was unable to detect HCC in 8 cases, representing false-negative. Out of 51 patients, 74.5% of HCC cases exhibited multifocal pattern. The maximum standardized uptake value (SUV max) of the primary malignant site ranged from 1.9 to 16.1, with a mean of 3.7 ± 2.8. The FDG PET-CT revealed abnormal sites of the uptake outside liver in 23 individuals. The research confirmed the tumor recurrence in four previously treated patients. In the conducted investigation, FDG PET-CT showed 84.3% sensitivity for the diagnosis of HCC. The study demonstrates that FDG PET-CT is a viable option for the detection of HCC. The sensitivity of FDG PET-CT in our population is comparable and in agreement with international data for diagnosis of HCC thereby favoring its reproducibility among geographical and ethnic groups. However, owing to the reduced ability of FDG PET-CT scan to identify well-differentiated/low-grade HCC, the routine use of FDG PET-CT scan may not be considered in cases requiring evaluation of primary disease only. Arshad K, Hanan SD, Younis MN, et al. Detection of Primary Hepatocellular Carcinoma on 18F-Fluorodeoxyglucose Positron Emission Tomography-computed Tomography. Euroasian J Hepato-Gastroenterol 2023;13(2):66-72.

18F]FDG PET-CT radiomics signature to predict pathological complete response to neoadjuvant chemoimmunotherapy in non-small cell lung cancer: a multicenter study.

This study aims to develop and validate a radiomics model based on 18F-fluorodeoxyglucose positron emission tomography-computed tomography ([18F]FDG PET-CT) images to predict pathological complete response (pCR) to neoadjuvant chemoimmunotherapy in non-small cell lung cancer (NSCLC). One hundred eighty-five patients receiving neoadjuvant chemoimmunotherapy for NSCLC at 5 centers from January 2019 to December 2022 were included and divided into a training cohort and a validation cohort. Radiomics models were constructed via the least absolute shrinkage and selection operator (LASSO) method. The performances of models were evaluated by the area under the receiver operating characteristic curve (AUC). In addition, genetic analyses were conducted to reveal the underlying biological basis of the radiomics score. After the LASSO process, 9 PET-CT radiomics features were selected for pCR prediction. In the validation cohort, the ability of PET-CT radiomics model to predict pCR was shown to have an AUC of 0.818 (95% confidence interval [CI], 0.711, 0.925), which was better than the PET radiomics model (0.728 [95% CI, 0.610, 0.846]), CT radiomics model (0.732 [95% CI, 0.607, 0.857]), and maximum standard uptake value (0.603 [95% CI, 0.473, 0.733]) (p < 0.05). Moreover, a high radiomics score was related to the upregulation of pathways suppressing tumor proliferation and the infiltration of antitumor immune cell. The proposed PET-CT radiomics model was capable of predicting pCR to neoadjuvant chemoimmunotherapy in NSCLC patients. This study indicated that the generated 18F-fluorodeoxyglucose positron emission tomography-computed tomography radiomics model could predict pathological complete response to neoadjuvant chemoimmunotherapy, implying the potential of our radiomics model to personalize the neoadjuvant chemoimmunotherapy in lung cancer patients. • Recognizing patients potentially benefiting neoadjuvant chemoimmunotherapy is critical for individualized therapy of lung cancer. • [18F]FDG PET-CT radiomics could predict pathological complete response to neoadjuvant immunotherapy in non-small cell lung cancer. • [18F]FDG PET-CT radiomics model could personalize neoadjuvant chemoimmunotherapy in lung cancer patients.

Prognostic Value of Semi-Quantitative 18F-FDG PET/CT Parameters in Hodgkin’s Lymphoma

Objective: To assess the prognostic value of maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) determined by 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) imaging in Hodgkin’s lymphoma patients. Methods: A total of 148 Hodgkin’s lymphoma patients diagnosed with lymph node biopsy from October 2014 to October 2015 were retrospectively analyzed followed by categorizing into good (125 cases) and poor (23 cases) prognosis groups. The chi-squared test was used to analyze the clinicopathological characteristics of Hodgkin’s lymphoma patients with the semi-quantitative 18F-FDG PET/CT parameters; the Spearman method was used to analyze the correlation between the semi-quantitative parameters and clinicopathological features of Hodgkin’s lymphoma; receiver operating characteristic curve was used to analyze the predictive value of the semi-quantitative parameters for poor prognosis of Hodgkin’s lymphoma patients. Results: Mean SUVmax, MTV, and TLG of the 148 cases of Hodgkin’s lymphoma were 7.26 ± 2.38, 12.46 ± 3.14 cm3, and 76.83 ± 18.56 g, respectively. Significant variations in the Ann Arbor stage and clinical classification were observed with different levels of semi-quantitative parameters (P &lt; 0.05). The semi-quantitative parameters were not correlated with age and gender (P &gt; 0.05) but positively correlated with Ann Arbor stage and clinical classification (P &lt; 0.05). These parameters in the poor prognosis group were higher than those in the good prognosis group (P &lt; 0.05). The area under the curve (AUC) of SUVmax, MTV, and TLG in predicting the poor prognosis group was 0.881, 0.875, and 0.838, with cut-off values of 7.264, 12.898 cm3, and 74.580g, as well as specificity of 88.8%, 84.0%, and 78.4%, and sensitivity of 87.0%, 87.0%, and 78.3%, respectively; the AUC of the combined prediction was 0.986, with a specificity of 97.6% and sensitivity of 86.3%. Conclusion: The semi-quantitative 18F-FDG PET/CT parameters provide valuable insights for Hodgkin’s lymphoma prognosis assessment.

The remodeling of metabolic brain pattern in patients with extracranial diffuse large B-cell lymphoma

BackgroundOwing to the advances in diagnosis and therapy, survival or remission rates for lymphoma have improved prominently. Apart from the lymphoma- and chemotherapy-related somatic symptom burden, increasing attention has been drawn to the health-related quality of life. The application of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) has been routinely recommended for the staging and response assessment of FDG-avid lymphoma. However, up till now, only a few researches have investigated the brain metabolic impairments in patients with pre-treatment lymphoma. The determination of the lymphoma-related metabolic brain pattern would facilitate exploring the tailored therapeutic regimen to alleviate not only the physiological, but also the psychological symptoms. In this retrospective study, we aimed to establish the diffuse large B-cell lymphoma-related pattern (DLBCLRP) of metabolic brain network and investigate the correlations between DLBCLRP and several indexes of the staging and response assessment.ResultsThe established DLBCLRP was characterized by the increased metabolic activity in bilateral cerebellum, brainstem, thalamus, striatum, hippocampus, amygdala, parahippocampal gyrus and right middle temporal gyrus and by the decreased metabolic activity in bilateral occipital lobe, parietal lobe, anterior cingulate gyrus, midcingulate cortex and medial frontal gyrus. Significant difference in the baseline expression of DLBCLRP was found among complete metabolic response (CMR), partial metabolic response (PMR) and progressive metabolic disease (PMD) groups (P < 0.01). DLBCLRP expressions were also significantly or tended to be positively correlated with international prognostic index (IPI) (rs = 0.306, P < 0.05), lg(total metabolic tumor volume, TMTV) (r = 0.298, P < 0.05) and lg(total lesion glycolysis, TLG) (r = 0.233, P = 0.064). Though no significant correlation of DLBCLRP expression was found with Ann Arbor staging or tumor SUVmax (P > 0.05), the post-treatment declines of DLBCLRP expression were significantly positively correlated with Ann Arbor staging (rs = 0.284, P < 0.05) and IPI (rs = 0.297, P < 0.05).ConclusionsThe proposed DLBCLRP would lay the foundation for further investigating the cerebral dysfunction related to DLBCL itself and/or treatments. Besides, the expression of DLBCLRP was associated with the tumor burden of lymphoma, implying a potential biomarker for prognosis.

Metabolic parameters predict survival and toxicity in chimeric antigen receptor T-cell therapy-treated relapsed/refractory large B-cell lymphoma.

CD19-targeted chimeric antigen receptor (CAR) T-cell therapy has revolutionized treatment for patients with relapsed/refractory large B-cell lymphoma (LBCL). However, data available concerning the impact of the prognostic value of quantitative 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT) parameters on the CAR T-related outcomes and toxicities are limited. Therefore, we aimed to evaluate the predictive value of pre- and post-CAR T metabolic parameters on survival and toxicities following CAR T-cell therapy. Fifty-nine patients with PET/CT scans done pre-and post-CAR T infusion were retrospectively identified and analyzed in a single institution database of LBCL patients treated with commercial CD19-targeted CAR T-cell therapy. The median follow-up was 10.7months [interquartile range (IQR): 2.6-25.5months]. The overall response (complete response-CR and partial response) and CR rates post-CAR T were 76% (n=45) and 53% (n=31), respectively. On univariate analysis, low pre-CAR T total lesion glycolysis (TLG) and metabolic tumor volume (MTV) predicted improved overall response post-CAR T (OR=4.7, p=0.01, OR=9.5, p=0.03, respectively) and CR post-CAR T (OR=12.4, p=0.0004, OR=10.9, p=0.0001, respectively). High TLG pre-CAR T was correlated with cytokine release syndrome (CRS, OR=3.25, p=0.04). High MTV pre-CAR T was correlated with developing immune effector cell neurotoxicity syndrome (ICANS) events (OR=4.3, p=0.01), and high SUV pre-CAR T was associated with grade 3-4 neurological events (OR=12, p=0.01). High MTV/TLG/SUVmax post-CAR T were significantly associated with inferior Overall survival (OS). On multivariate analysis, high TLG pre-CAR T (HR=2.4, p=0.03), age ≥60 (HR=2.7, p=0.03), and bulky disease (≥5cm) at the time of apheresis (HR=2.5, p=0.02) were identified to be independent prognostic factors for inferior PFS. High MTV post-CAR T was identified as the most prognostic factor associated with inferior OS.

Predicting diffuse large B-cell lymphoma outcomes with lesion-to-liver maximum standardized uptake value for interim-treatment and end-of-treatment positron emission tomography-computed tomography.

18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) has been used in response evaluation systems for malignant lymphomas and is an important tool for determining efficacy and prognosis. The Deauville 5-point scale (D-5PS) is an 18F-FDG PET-CT image-interpretation protocol for patients with lymphoma. Nevertheless, a number of limitations in visual image interpretation, such as interobserver disagreement and the increase of false-positive results, suggests that new parameters are needed. In this study, we aimed to evaluate the prognostic values of interim-treatment (I-) and end-of-treatment (EOT) PET-CT by comparing D-5PS to the semiquantitative lesion-to-liver maximum standardized uptake value ratio (RLL). A total of 90 patients with diffuse large B-cell lymphoma (DLBCL) (45 I-PET and 45 EOT-PET) were analyzed, and the RLL was calculated. Patients were additionally evaluated using the D-5PS system. We determined the optimal cutoff value of RLL using receiver operating characteristic (ROC) analysis. Kaplan-Meier survival analysis was used to compare the outcome predictions, while multivariate Cox regression analysis was used to identify the predictive factors. Among the patients examined, 41 (20 I-PET and 21 EOT-PET) experienced progression, and 49 (25 I-PET, 24 EOT-PET) did not. The optimal cutoff values of the RLL for predicting disease progression were 1.37 for I-PET (sensitivity 75%, specificity 88%) and 2.03 for EOT-PET (sensitivity 45.5%, specificity 100%), while the cutoffs of the D-5PS were scores 4 for I-PET (sensitivity 80%, specificity 72%) and 5 for EOT-PET (sensitivity 40.9%, specificity 100%). The prognostic efficacy was higher for the RLL at interim than for the D-5PS [area under the curve (AUC) =0.848 vs. 0.741]. The EOT prognostic efficacy of both evaluation methods was essentially equivalent (AUC =0.785 vs. 0.725). Univariate and multivariate analyses showed that RLL and D-5PS were independent factors affecting DLBCL outcomes for both interim and EOT assessment. RLL and D-5PS have independent predictive values for the interim and EOT evaluation of outcomes in patients with DLBCL. The RLL has better interim predictive ability than does D-5PS and can optimize D-5PS interpretation, thus improving interim outcome prediction.

The Effects of Human Papillomavirus Status and Treatment on the Positive Predictive Value of Post-radiotherapy 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography in Advanced Head and Neck Squamous Cell Carcinoma

AimsThe high negative predictive value of post-chemoradiation (CRT) positron emission tomography-computed tomography (PET-CT) is well established in head and neck squamous cell cancers (HNSCC). The positive predictive value (PPV) remains under scrutiny, with increasing evidence that it is affected by several factors. The aim of this study was to assess the PPV of post-treatment PET-CT for residual nodal disease when stratified by treatment modality and tumour human papillomavirus (HPV) status. Materials and methodsThis was a retrospective cohort study in a tertiary oncology centre carried out between January 2013 and December 2019. Patients were radically treated with radiotherapy only/CRT for node-positive HNSCC. PET-CT nodal responses were categorised as complete, equivocal (EQR) or incomplete (ICR), and outcomes extracted from electronic records. ResultsIn total, 480 patients were evaluated, all had a minimum potential follow-up of 2 years, with a median of 39.2 months. The PPV of 12-week PET-CT was significantly different between HPV-positive (22.5%) and HPV-unrelated (52.7%) disease, P < 0.001. It was also significantly different between the CRT (24.8%) and radiotherapy-only (51.1%) groups, P = 0.001. The PPV of an EQR was significantly less than an ICR, irrespective of HPV status and primary treatment modality. In HPV-positive disease, the PPV of an EQR was 9.0% for the CRT group compared with 21.4% for radiotherapy only, P = 0.278. The PPV in those who achieved an ICR was 34.2% in the CRT group, significantly lower than 70.0% in the radiotherapy-only group, P = 0.03. ConclusionThe PPV of 12-week PET-CT is significantly lower for HPV-positive compared with HPV-unrelated HNSCC. It is poorer in patients with HPV-positive disease treated with CRT compared with radiotherapy alone.

55 Outcomes of FDG PET-CT in Surveillance of Residual Nodal Metastases Following Non-Surgical Management of Head and Neck Squamous Cell Carcinoma: A Retrospective Review

Abstract Aim Assessing the role of positron emission tomography-computed tomography (PET-CT) surveillance in detecting residual disease in nodal metastasis, following non-surgical treatment of Head and neck squamous cell carcinoma (HNSCC), such as chemoradiotherapy or radical radiotherapy. To analyse differences in outcomes between HPV positive and HPV negative cancers. Method Retrospective analysis of 327 patients in South Wales, with histologically proven HNSCC was conducted. All patients were treated non-surgically and post-treatment PET-CT scans were obtained. Patients with PET-CT showing incomplete responses had further analysis of outcomes assessed via surgical histology of the nodes. Outcomes in patients with p16 positive disease were recorded to determine outcomes in HPV positive individuals. Results 64 individuals had residual nodal tumours according to PET-CT. 18 out of 43 patients had a negative histology for malignancy, of which 12 showed p16 positive disease. PET-CT showed a false positive in 41.8% of patients, with a positive predictive value of 58%. 225 patients in total were p16 positive, and 38 out of the 64 residual patients had p16 positive disease. There was no significant difference in outcomes between p16 positive and negative patients. Conclusions Our study concurs with similar literature, that primary CRT in N2 and N3 nodal metastasis followed by PET-CT surveillance minimises unnecessary neck dissections and triple modality treatment. Further research needs to be conducted however, to determine the efficacy of PET-CT surveillance compared to planned neck dissections. Furthermore, outcomes in p16 positive patients requires additional ongoing research to best determine surveillance techniques and long-term health outcomes.

Impact of retention index on the neoadjuvant chemotherapy effect and the prognosis in oesophageal cancer.

The relationship between retention index calculated from dual-time point 18F-fluorodeoxyglucose positron emission tomography-computed tomography and oesophageal cancer prognosis remains unknown. This study aimed to determine usefulness of retention index as a predictor of long-term prognosis of oesophageal cancer and neoadjuvant chemotherapy efficacy. A total of 151 patients with oesophageal cancer who underwent esophagectomy were evaluated retrospectively in this study. We acquired positron emission tomography scans 60 and 120min (SUVmax1 and SUVmax2, respectively) after the intravenous administration of 3.7 Mbq/kg 18F-fluorodeoxyglucose. The patients were divided into two groups: high-retention index (retention index ≥29%, 107 patients) and low-retention index (retention index <29%, 44 patients). Retention index was calculated as follows: retention index (%)=[(SUVmax2 - SUVmax1)/SUVmax1]×100. The overall survival and relapse-free survival rates in the high-retention index group were significantly lower than those in the low-retention index group (P<0.001). Our multivariate analysis identified that the high-retention index group contained independent risk factors for overall survival (hazard ratio: 2.44, P=0.009) and relapse-free survival (hazard ratio: 2.61, P=0.002). The high-retention index group exhibited a lower partial response rate to neoadjuvant chemotherapy evaluated by computed tomography (P<0.001) and a lower pathological therapeutic effect in the resected specimen (P=0.019) than the low-retention index group. The retention index was associated with neoadjuvant chemotherapy responses and long-term prognosis for oesophageal cancer.

Preoperative prediction of lymphovascular invasion of colorectal cancer by radiomics based on 18F-FDG PET-CT and clinical factors.

The purpose of this study was to investigate the value of a clinical radiomics model based on Positron emission tomography-computed tomography (PET-CT) radiomics features combined with clinical predictors of Lymphovascular invasion (LVI) in predicting preoperative LVI in patients with colorectal cancer (CRC). A total of 95 CRC patients who underwent preoperative 18F-fluorodeoxyglucose (FDG) PET-CT examination were retrospectively enrolled. Univariate and multivariate logistic regression analyses were used to analyse clinical factors and PET metabolic data in the LVI-positive and LVI-negative groups to identify independent predictors of LVI. We constructed four prediction models based on radiomics features and clinical data to predict LVI status. The predictive efficacy of different models was evaluated according to the receiver operating characteristic curve. Then, the nomogram of the best model was constructed, and its performance was evaluated using calibration and clinical decision curves. Mean standardized uptake value (SUVmean), maximum tumour diameter and lymph node metastasis were independent predictors of LVI in CRC patients (P < 0.05). The clinical radiomics model obtained the best prediction performance, with an Area Under Curve (AUC) of 0.922 (95%CI 0.820-0.977) and 0.918 (95%CI 0.782-0.982) in the training and validation cohorts, respectively. A nomogram based on the clinical radiomics model was constructed, and the calibration curve fitted well (P > 0.05). The clinical radiomics prediction model constructed in this study has high value in the preoperative individualized prediction of LVI in CRC patients.

Limitation of PET/CT for screening of synchronous upper gastrointestinal cancer in oral cancer patients

ObjectivePatients with squamous cell carcinoma (SCC) of the head and neck including the oral cavity have a high risk of upper gastrointestinal cancer, especially esophageal cancer. Synchronous upper gastrointestinal cancers affect the field of radiation or surgery, and undetected double cancer can cause poor prognosis. The purpose of this retrospective study was to evaluate the diagnostic performance of 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for detecting synchronous upper gastrointestinal cancer at the initial staging of oral cancer patients. MethodsBetween September 2006 and August 2021, 804 newly diagnosed oral squamous cell carcinoma patients who undergo esophagogastroduodenoscopy (EGD) and FDG-PET/CT at the initial staging were enrolled in this study. The incidence of synchronous upper gastrointestinal cancer in EGD screening at the initial staging of oral cancer was retrospectively calculated. Furthermore, we evaluated the diagnostic performance of FDG-PET/CT for screening of synchronous upper gastrointestinal cancer in oral cancer patients. ResultsThe incidence of synchronous upper gastrointestinal cancer in EGD screening at the initial staging of oral cancer was 4.2% (34/804 patients). Of 34 oral cancer patients with synchronous upper gastrointestinal cancer, 26 (76.5%) had both smoking and drinking habits. The sensitivity, specificity, accuracy, false-negative rate, false-positive rate, positive predictive value, and negative predictive value of FDG-PET/CT for synchronous upper gastrointestinal cancer were 44.1%, 99.6%, 97.3%, 55.9%, 0.4%, 83.3%, and 97.6%, respectively. ConclusionsBecause PET/CT cannot sufficiently detect synchronous upper gastrointestinal cancer in oral SCC patients, EGD screening before the treatment may be suitable for the high-risk oral SCC patients.

Added Clinical Value of 18F-FDG-PET/CT to Stage Patients With High-Risk Non-Muscle Invasive Bladder Cancer Before Radical Cystectomy.

18F-fluorodeoxyglucose positron-emission tomography-computed tomography (FDG-PET/CT) is increasingly used in the preoperative staging of patients with muscle-invasive bladder cancer. The clinical added value of FDG-PET/CT in high-risk non-muscle invasive bladder cancer (NMIBC) is unknown. In this study, the value of FDG-PET/CT in addition to contrast enhanced (CE)-CT was evaluated in high-risk NMIBC before radical cystectomy (RC). This is a retrospective analysis of consecutive patients with high risk and very-high risk urothelial NMIBC scheduled for RC in a tertiary referral center between 2011 and 2020. Patients underwent staging with CE-CT (chest and abdomen/pelvis) and FDG-PET/CT. We assessed the clinical disease stage before and after FDG-PET/CT and the treatment recommendation based on the stage before and after FDG-PET/CT. The accuracy of CT and FDG-PET/CT for identifying metastatic disease was defined by the receiver-operating curve using a reference-standard including histopathology/cytology (if available), imaging and follow-up. A total of 92 patients were identified (median age: 71 years). In 14/92 (15%) patients, FDG-PET/CT detected metastasis (12 suspicious lymph nodes and 4 distant metastases). The disease stage changed in 11/92 (12%) patients based on additional FDG-PET/CT findings. FDG-PET/CT led to a different treatment in 9/92 (10%) patients. According to the reference standard, 25/92 (27%) patients had metastases. The sensitivity, specificity and accuracy of FDG-PET/CT was 36%, 93% and 77% respectively, versus 12%, 97% and 74% of CE-CT only. The area under the ROC curve was 0.643 for FDG-PET/CT and 0.545 for CT, P=.036. The addition of FDG-PET/CT to CE-CT imaging changed the treatment in 10% of patients and proved to be a valuable diagnostic tool in a selected subgroup of NMIBC patients scheduled for RC.

Therapeutic Effect of Dupilumab on Systemic and Vascular Inflammation in Adults with Severe Atopic Dermatitis: Feasibility Study Using 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography

Atopic dermatitis (AD) is an inflammatory skin disease associated with increased systemic and vascular inflammation. Although dupilumab has been proven to be effective against severe AD, imaging studies analysing its inflammation-reducing effect have rarely been reported. The aim of this study was to evaluate the effect of dupilumab on systemic and vascular inflammation in adult patients with severe AD, using 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT). A total of 33 adult patients with severe AD and 25 healthy controls underwent 18F-FDG PET/CT at baseline. Patients on dupilumab treatment underwent 18F-FDG PET/CT again after achieving a 75% reduction from baseline on the Eczema Area and Severity Index (EASI-75). Patients with AD exhibited increased 18F-FDG uptake values in the liver, spleen, pancreas, and carotid artery compared with healthy controls. However, compared with baseline, there was no statistically significant difference in 18F-FDG uptake in major organs and arteries after achieving EASI-75 with dupilumab treatment. In conclusion, while dupilumab treatment resulted in a significant clinical improvement and reduced serum inflammatory markers in adult patients with severe AD, no changes in systemic and vascular inflammation were observed on 18F-FDG PET/CT imaging.

FDG and Non-FDG Radiopharmaceuticals for PET Imaging in Invasive Lobular Breast Carcinoma.

Invasive lobular cancer (ILC) is the second most frequent histological type of breast cancer (BC) and includes a heterogeneous spectrum of diseases with unique characteristics, especially the infiltrative growth pattern and metastatic spread. [18F]fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT) is extensively used in oncology and BC patient evaluation. Its role in ILCs is considered suboptimal due to its low FDG avidity. Therefore, ILCs could benefit from molecular imaging with non-FDG tracers that target other specific pathways, contributing to precision medicine. This narrative review aims to summarize the current literature on the use of FDG-PET/CT in ILC and to discuss future opportunities given by the development of innovative non-FDG radiotracers.