Benefit of [18F]-FDG PET/CT for treatment-naïve nasopharyngeal carcinoma

The 9th Version of the AJCC Staging System for Nasopharyngeal Carcinoma: A Guide for Radiologists

The 9th version of the AJCC staging system for nasopharyngeal carcinoma introduces important refinements, emphasizing improved prognostic accuracy, clarity, and clinical relevance. Building on the 8th version, it refines TNM classifications to address limitations in survival outcome stratification and incorporates new criteria. Specifically, the 9th version clarifies the criteria for T3 disease by requiring unequivocal evidence of bone involvement, namely of the skull base (including pterygoid plates), cervical vertebrae, or paranasal sinuses. It additionally introduces advanced radiologic extranodal extension as a criterion for the N3 category and subclassifies M1 disease into M1a (3 or fewer metastatic lesions) versus M1b (more than 3 metastatic lesions) disease to enhance risk stratification. Developed through extensive multicenter studies and validated by international panels, the 9th version redefines NPC stage groups, aligning clinical management with evidence-based practices and improving prognostic accuracy. This review highlights key modifications in the 9th version that are relevant to radiologists, providing imaging examples and considering implications for clinical practice, prognosis, and treatment planning.

Evaluation of induction chemotherapy response using multiphasic dual-energy CT in nasopharyngeal carcinoma

OBJECTIVES

To develop a nomogram that assists in selecting nasopharyngeal carcinoma (NPC) patients suitable for induction chemotherapy.

MATERIALS AND METHODS

This retrospective study included NPC patients who underwent multiphasic contrast‑enhanced DECT (comprising non-contrast, arterial, and venous phase scanning) between May 2019 and December 2023. The relationships between quantitative DECT-derived parameters and treatment response to induction chemotherapy were analyzed using logistic regression analysis. The predictive performance of a nomogram integrating key predictors was assessed using the area under the receiver operating characteristic curve (AUC).

RESULTS

A total of 294 patients (median age, 53 years; interquartile range, 46-59 years; 224 men) were included. Among these, 215 were responders and 79 were non-responders. The normalized iodine concentration in the arterial phase (nICarterial) (odds ratio (OR), 0.71; 95% confidence interval (CI), 0.52-0.98; p = 0.036), arterial enhancement fraction (AEF) (OR, 1.45; 95% CI, 1.04-2.00; p = 0.026), and extracellular volume fraction (ECVf) (OR, 0.65; 95% CI, 0.15-0.87; p = 0.019) of tumors were identified as independent predictors of chemotherapy response. This nomogram demonstrated excellent performance (AUC = 0.803 [95% CI, 0.740-0.864]) across all participants, as well as in subgroup analyses of Epstein-Barr virus DNA (high and low) (AUC: 0.761, 0.799) and across five subgroups with different chemotherapy regimens (AUC, 0.773-0.833).

CONCLUSIONS

We developed a comprehensive nomogram to predict treatment response to induction chemotherapy by integrating nICarterial, AEF, and ECVf. This nomogram demonstrated superior predictive performance compared to the individual parameters when assessed separately.

KEY POINTS

Question To date, no reliable method has been established to predict the efficacy of induction chemotherapy for nasopharyngeal carcinoma prior to treatment. Findings nICarterial, AEF, and ECVf were the independent predictors of induction chemotherapy response, and the combined nomogram demonstrated strong performance to predict response. Clinical relevance The multiphasic contrast‑enhanced parameters derived from dual-energy CT offer a noninvasive approach to predict treatment response to induction chemotherapy and identify nasopharyngeal carcinoma patients who may benefit from induction chemotherapy.

Utilization of 18F-FDG Standardized Uptake Value and Metabolic Tumor Volume to Predict Local Failure in Nasopharyngeal Carcinoma

INTRODUCTION

The aim was to evaluate the prognostic values of pretreatment 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) parameters for predicting local failure in nasopharyngeal carcinoma (NPC) patients in the intensity-modulated radiotherapy (IMRT) era.

METHODS

Retrospective analysis was performed on 759 patients with NPC who underwent pretreatment 18F-FDG PET. The optimal cutoff values for maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) were determined by receiver operating characteristic curve analysis. Univariate and multivariate analysis was performed to identify the prognostic factors influencing local failure-free survival (LFFS). Survival curves for the different risk groups were plotted using the Kaplan-Meier survival analysis method and compared using the log-rank test.

RESULTS

The median follow-up period was 49.0 months (range: 3.0-118.0 months). The optimal cutoff of SUVmax and MTV were 7.44 and 22.21 mL, respectively. Patients with higher SUVmax and MTV were associated with worse LFFS. The survival curves of different groups were significantly separated. The univariate analysis showed the statistical significance of SUVmax, MTV, and their composite in LFFS (p = 0.002 for SUVmax; p = 0.001 for MTV; p < 0.002 for their composite). The multivariate analysis showed that higher SUVmax and MTV was an independent negative prognostic factor for LFFS (HR = 1.805, 95% CI: 1.004-3.245, p = 0.049). The subgroups of stages III-IV further confirmed the impact of SUVmax and MTV on LFFS (HR = 1.884, CI: 1.087-3.708, p = 0.026).

CONCLUSION

Patients with higher SUVmax and MTV were associated with local failure as well as in the III-IV advanced stage.

Pretreatment FDG PET in prognosis of locoregionally advanced nasopharyngeal carcinoma treated with intensity-modulated radiation therapy

Objectives: We aimed to investigate the long-term survival benefit of PET/CT compared with the routine examination (chest CT, abdominal enhanced CT and emission computed tomography (ECT)) for locally advanced nasopharyngeal carcinoma (NPC) before treatment. Methods: From June 8th 2005 to August 10th 2017, 507 histologically diagnosed NPC patients with the 8th AJCC/UICC staging criteria III-IVA were enrolled in this study. Among them, patients underwent chest CT, abdominal enhanced CT and bone emission CT (control group), or replaced by positron emission tomography-CT (PET-CT group) to check for distant metastases. Results: The numbers of patients in the control and PET-CT group were 344 (67.9%) and 163 (32.1%), respectively. With the median follow-up of 72 months, a total of 127 (25.0%) patients died. The 5-year and 8-year overall survival (OS) rates of the control and PET-CT group were 81.1% and 86.9%, 70.8% and 74.6% (P=0.087), respectively. Patients with T1-3, III stage and TPF showed improved 5-year and 8-year OS rates compared with T4, IVA stage and PF patients (P=0.001, P=0.000 and P=0.009). Patients with initially PET-CT-based staged showed improved 5-year and 8-year distant control (DC) compared with the control group (90.6% vs. 83.3% and 90.6% vs. 81.0%, P=0.013). There was no significant difference in local control (LC) and regional control (RC), between the control and PET-CT group. Conclusions: Patients with initially PET-CT-based staged showed improved long-term DC compared with the control group. Initially PET-CT-based staged is recommended routinely in locoregionally advanced NPC.

Metachronous Second Primary in the Form of Nasopharyngeal Carcinoma Following Treatment of Small Cell Neuroendocrine Carcinoma of the Head and Neck: Dual Tracer PET/CT Findings Highlighting SSTR2 Expression and Its Theranostic Implications

Patients of head and neck squamous cell carcinoma (HNSCC) experience increased risk of developing second primary cancer (SPC) necessitating active surveillance during their disease course. SPCs are associated with poor prognosis and are the leading cause of long-term morbidity and mortality impacting survival of patients with HNSCC. Small cell neuroendocrine carcinoma (SmNEC) is a rare but aggressive neoplasm with poor prognosis and high risk of local recurrence and distant metastasis. We report an exceedingly rare case of nasopharyngeal carcinoma (NPC) presenting as a recurrence in the form of metachronous second primary to primary SmNEC 9 years after chemotherapy. The dual tracer positron emission tomography and computed tomography (PET/CT) imaging approach ([ 68 Ga]Ga-DOTATATE-PET/CT with 18 F-FDG-PET/CT) was explored in such metachronous NPCs, and the findings are illustrated with its potential for theranostic applications. NPC is a rare malignancy with significant geographical variations in incidence rates. Somatostatin receptor 2 (SSTR2) expression in NPC is well documented and can serve as a potential theragnostic marker in advanced NPC where the successful outcome is minimal with currently available treatment modalities.

A head-to-head comparison of [68Ga]Ga-DOTATATE and [68Ga]Ga-FAPI PET/CT in patients with nasopharyngeal carcinoma: a single-center, prospective study

PURPOSE

We aimed to compare the staging efficiency of [68Ga]Ga-DOTATATE and [68Ga]Ga-FAPI PET/CT in nasopharyngeal carcinoma (NPC) patients.

METHODS

Thirty-nine patients with pathologically confirmed NPC were enrolled in this prospective study. Each patient underwent paired [68Ga]Ga-DOTATATE and [68Ga]Ga-FAPI PET/CT on 2 successive days. The accuracy of two PET/CT for assessing T, N, and M stages was compared by using head-and-neck MRI, histopathologic diagnosis and follow-up results as reference standards. The radiotracer uptake derived from two PETs was also compared.

RESULTS

For treatment-naïve patients, [68Ga]Ga-DOTATATE PET/CT showed identical sensitivity for the primary tumours but clearer tumor delineation induced by higher tumour-to-background (TBR) ratio (19.1 ± 8.7 vs. 12.4 ± 7.7, P = 0.003), compared with [68Ga]Ga-FAPI PET/CT. Regarding cervical lymph node (CLN) metastases, [68Ga]Ga-DOTATATE PET had significantly better sensitivity and accuracy based on neck sides (98% vs. 82%, P < 0.001; 99% vs. 88% P = 0.008), neck levels (98% vs. 78%, 99% vs. 97%; both P < 0.001) and individual nodes (89% vs. 56%, 91% vs. 76%; both P < 0.001), and higher TBR (8.1 ± 4.1 vs. 6.3 ± 3.7, P < 0.001). Additionally, [68Ga]Ga-DOTATATE PET/CT revealed higher sensitivity and accuracy for distant metastases (96% vs. 53%, 95% vs. 52%; both P < 0.001), particularly in bone metastases (99% vs. 49%, 97% vs. 49%; both P < 0.001). For post-treatment patients, [68Ga]Ga-DOTATATE PET/CT identified one more true-negative case than [68Ga]Ga-FAPI PET/CT.

CONCLUSION

[68Ga]Ga-DOTATATE PET/CT performed better than [68Ga]Ga-FAPI PET/CT in visualizing the primary tumours, detecting the metastatic lesions and identifying the local recurrence, suggesting [68Ga]Ga-DOTATATE PET/CT may be superior to [68Ga]Ga-FAPI PET/CT for NPC staging.

Metabolic reprogramming in the pathogenesis and progression of nasopharyngeal carcinoma: molecular mechanisms and therapeutic implications

Nasopharyngeal carcinoma (NPC) is a unique head and neck cancer with a complex etiology involving genetic predispositions, environmental factors, and Epstein-Barr virus (EBV) infection. Despite progress in radiotherapy and chemotherapy, the prognosis for advanced NPC is still unfavorable, prompting the need for innovative therapeutic approaches. Metabolic reprogramming plays a crucial role in the development and progression of NPC, marked by substantial changes in glycolysis, lipid, and amino acid metabolism. These alterations aid tumor cell proliferation, survival under stress, and immune evasion, with features such as enhanced aerobic glycolysis (Warburg effect) and shifts in lipid and amino acid pathways. Oncogenic drivers like MYC, RAS, EGFR, and the loss of tumor suppressors such as TP53 and PTEN, along with key signaling pathways including mTOR, AMPK, and HIF-1α, orchestrate these metabolic changes. This review discusses the molecular mechanisms of metabolic reprogramming in NPC and outlines potential therapeutic targets within these pathways. Advances in metabolic imaging and biomarker discovery are also enhancing the precision of diagnostics and treatment monitoring, fostering personalized medicine in NPC treatment. This manuscript aims to provide a detailed overview of the current research and its implications for improving NPC management and patient outcomes through targeted metabolic therapies.

Noninvasive Photothermal Therapy of Nasopharyngeal Cancer Guided by High Efficiency Optical-Absorption Nanomaterial Enhanced by NIR-II Photoacoustic Imaging

Background

Photothermal therapy (PTT) guided by photoacoustic imaging (PAI) using nanoplatforms has emerged as a promising strategy for cancer treatment due to its efficiency and accuracy. This study aimed to develop and synthesize novel second near-infrared region (NIR-II) absorption-conjugated polymer acceptor acrylate-substituted thiadiazoloquinoxaline-diketopyrrolopyrrole polymers (PATQ-DPP) designed specifically as photothermal and imaging contrast agents for nasopharyngeal carcinoma (NPC).

Methods

The PATQ-DPP nanoparticles were synthesized and characterized for their optical properties, including low optical band gaps. Their potential as PTT agents and imaging contrast agents for NPC was evaluated both in vitro and in vivo. The accumulation of nanoparticles at tumor sites was assessed post-injection, and the efficacy of PTT under near-infrared laser irradiation was investigated in a mouse model of NPC.

Results

Experimental results indicated that the PATQ-DPP nanoparticles exhibited significant photoacoustic contrast enhancement and favorable PTT performance. Safety and non-toxicity evaluations confirmed the biocompatibility of these nanoparticles. In vivo studies showed that PATQ-DPP nanoparticles effectively accumulated at NPC tumor sites and demonstrated excellent tumor growth inhibition upon exposure to near-infrared laser irradiation. Notably, complete elimination of nasopharyngeal tumors was observed within 18 days following PTT.

Discussion

The findings suggest that PATQ-DPP nanoparticles are a promising theranostic agent for NIR-II PAI and PTT of tumors. This innovative approach utilizing PATQ-DPP nanoparticles provides a powerful tool for the early diagnosis and precise treatment of NPC, offering a new avenue in the management of this challenging malignancy.

Low-density lipoprotein cholesterol-to-lymphocyte count ratio (LLR) is a promising novel predictor of postoperative new-onset deep vein thrombosis following open wedge high tibial osteotomy: a propensity score-matched analysis

BACKGROUND

The association of low-density lipoprotein cholesterol (LDL-C) and lymphocyte counts with the development of deep vein thrombosis (DVT) has been demonstrated in many fields but remains lacking in open wedge high tibial osteotomy (OWHTO). This study aimed to assess the predictive value of LDL-C to lymphocyte count ratio (LLR) in screening for postoperative new-onset DVT.

METHODS

Clinical data were retrospectively collected from patients who underwent OWHTO between June 2018 and May 2023. The limited restricted cubic spline (RCS) was conducted to evaluate the nonlinear relationship between LLR and the risk of postoperative new-onset DVT. The receiver operating characteristic (ROC) curves were plotted and the predictive value of biomarkers was assessed. After adjusting for intergroup confounders by propensity score matching, the univariate logistic regression was applied to assess the association between LLR and DVT.

RESULTS

1293 eligible patients were included. RCS analysis showed a linear positive correlation between LLR and the risk of DVT (P for overall = 0.008). We identified LLR had an area under the curve of 0.607, accuracy of 74.3%, sensitivity of 38.5%, and specificity of 80.7%, and LLR > 1.75 was independently associated with a 1.45-fold risk of DVT (95% CI: 1.01-2.08, P = 0.045). Furthermore, significant heterogeneities were observed in the subgroups of age, BMI, diabetes mellitus, hypertension, Kellgren-Lawrence grade, the American Society of Anesthesiologists (ASA) score, and intraoperative osteotomy correction size.

CONCLUSION

LLR is a valuable biomarker for predicting postoperative new-onset DVT in patients with OWHTO, and routine screening is expected to yield positive benefits.

Tata Memorial Centre Evidence Based Use of Nuclear medicine diagnostic and treatment modalities in cancer

ABSTRACT

PET/CT and radioisotope therapy are diagnostic and therapeutic arms of Nuclear Medicine, respectively. With the emergence of better technology, PET/CT has become an accessible modality. Diagnostic tracers exploring disease-specific targets has led the clinicians to look beyond FDG PET. Moreover, with the emergence of theranostic pairs of radiopharmaceuticals, radioisotope therapy is gradually making it's way into treatment algorithm of common cancers in India. We therefore would like to discuss in detail the updates in PET/CT imaging and radionuclide therapy and generate a consensus-driven evidence based document which would guide the practitioners of Oncology.

Retrospective analysis of the 18F-FDG PET/CT cutoff value for metabolic parameters was performed as a prediction model to evaluate risk factors for endometrial cancer

PURPOSE

The study retrospectively analyzed the accuracy and predictive ability of preoperative integrated whole-body 18F-FDG PET/CT for the assessment of high-risk factors in patients with endometrial carcinoma (EC).

MATERIALS AND METHODS

A total of 205 patients with endometrial cancer who underwent preoperative PET/CT at Shanghai General Hospital from January 2018 to December 2021 were retrospectively evaluated and last follow-up was June 2023. Our study evaluated the ability and optimal cutoff values of three metabolic and volumetric parameters-standardized uptake value (SUV), metabolic tumor volume (MTV) and total lesion glycolysis (TLG)-to predict deep myometrial invasion (DMI), endocervical stroma invasion (ESI) and lymph node metastases (LNM) in endometrial cancer. The accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of PET/CT were used to assess the diagnostic performance for the prediction.

RESULTS

Our study demonstrated a significant relationship between SUVmax (11.29, 17.38, 9.47), SUVmean (5.20, 6.12, 4.49), MTV (38.15, 36.28, 33.79 ml), and TLG (199.30, 225.10, 156.40 g) on PET/CT and histologically confirmed DMI, ESI and LNM in endometrial carcinoma (EC), with sensitivity, specificity, accuracy, PPV, and NPV of 100%/100%/100%, 96.53%/98.89%/87.14%, 97.56%/99.02%/91.22%, 92.42%/92.85%/78.31%, and 100%/100%/100%, respectively. Our study showed a risk model based on optimal cutoff values for MTV and TLG of 19.6 ml/126.3 g, 20.54 ml/84.80 g and 24 ml/49.83 g to preoperatively predict DMI, ESI, and LNM, respectively, in endometrial carcinoma. The 4-year OS (HR) for Stage IA, IB, II, III and IV according to 2009 FIGO was 98.00% (0.22), 95.20% (0.04), 83.90% (0.18), 90.50% (0.09) and 60% (0.51). Accordingly, estimated 4-year DFS (HR) for the stage IA-III was 98% (0.02), 95.20% (0.05), 76.90% (0.27) and 76.30% (0.35), all the patients in stage IV occurred recurrence and progression.

CONCLUSION

The present study showed patients with MTV > = 19.6 ml of MI and PET- positive LN with MTV cutoff > = 24 ml tended to predict poor OS and PFS in endometrial carcinoma. The cutoff of MTV and TLG in PET/CT assessment could be an independent prognostic factors to predict aggressive forms of EC.

Evaluation of 11 C-Choline PET/CT for T Staging and Tumor Volume Delineation in Nasopharyngeal Cancer Patients in Comparison to 18 F-FDG PET/CT

PURPOSE

Accurate determination of the primary tumor extension of nasopharyngeal carcinoma (NPC) by 18 F-FDG PET/CT is limited by the high physiological 18 F-FDG uptake in the surrounding area, especially in the brain tissue. We aimed to assess whether 11 C-choline PET/CT could improve the accuracy of T staging and tumor volume delineation for NPC patients.

METHODS

Patients with pathologically confirmed diagnosis of NPC were enrolled. The primary tumor extension of each patient was evaluated by 11 C-choline PET/CT, 18 F-FDG PET/CT, and contrast-enhanced MRI. The PET/CT-based tumor volume ( VPET ) was measured by 3 threshold methods, including the threshold of SUV 2.5 (Th 2.5 ), 40% of maximal SUV (Th 40% ), and the relative background-dependent threshold (Th bgd ). Tumor volume and Dice similarity coefficient were compared among VPET with different segmentation methods and VMR .

RESULTS

Thirty-three patients with treatment-naive NPC and 6 patients with suspicious recurrent disease were enrolled. The NPC lesions were avid for both 11 C-choline and 18 F-FDG. Visual analysis showed that 11 C-choline PET/CT had better contrast and higher discernability than 18 F-FDG PET/CT for intracranial, skull base, and orbital involvement. 11 C-choline PET/CT also exhibited advantage over MRI for differentiation between local recurrence and radiation-induced alterations. For the tumor delineated, the VMR was larger than VPET in general, except for 18 F-FDG PET/CT with Th 2.5 threshold. For all 3 threshold methods applied, 11 C-choline PET/CT produced more consistent and comparable tumor volume to MRI than 18 F-FDG PET/CT. 11 C-choline PET/CT with Th bgd threshold showed the closest tumor volume and highest similarity to MRI.

CONCLUSIONS

11 C-choline PET/CT provides a higher accuracy than 18 F-FDG PET/CT in mapping tumor extension in locally advanced NPC and may be a promising complement to MRI in delineating the primary tumor.

Non-invasive molecular imaging for precision diagnosis of metastatic lymph nodes: opportunities from preclinical to clinical applications

Lymph node metastasis is an indicator of the invasiveness and aggressiveness of cancer. It is a vital prognostic factor in clinical staging of the disease and therapeutic decision-making. Patients with positive metastatic lymph nodes are likely to develop recurrent disease, distant metastasis, and succumb to death in the coming few years. Lymph node dissection and histological analysis are needed to detect whether regional lymph nodes have been infiltrated by cancer cells and determine the likely outcome of treatment and the patient's chances of survival. However, these procedures are invasive, and tissue biopsies are prone to sampling error. In recent years, advanced molecular imaging with novel imaging probes has provided new technologies that are contributing to comprehensive management of cancer, including non-invasive investigation of lymphatic drainage from tumors, identifying metastatic lymph nodes, and guiding surgeons to operate efficiently in patients with complex lesions. In this review, first, we outline the current status of different molecular imaging modalities applied for lymph node metastasis management. Second, we summarize the multi-functional imaging probes applied with the different imaging modalities as well as applications of cancer lymph node metastasis from preclinical studies to clinical translations. Third, we describe the limitations that must be considered in the field of molecular imaging for improved detection of lymph node metastasis. Finally, we propose future directions for molecular imaging technology that will allow more personalized treatment plans for patients with lymph node metastasis.

Prognostic value of pre-treatment FDG PET/CT SUVmax for metastatic lesions in de novo metastatic nasopharyngeal carcinoma following chemotherapy and locoregional radiotherapy

BACKGROUND

To explore the prognostic role of FDG PET/CT maximal standard uptake values of metastatic lesions (SUVmax-M) in patients with de novo metastatic nasopharyngeal carcinoma (mNPC) following palliative chemotherapy and locoregional radiotherapy (LRRT).

METHODS

We retrospectively collected the information of 86 eligible patients between Jan 2012 and Oct 2020. All the parameters involving SUVmax and serum lactate dehydrogenase (LDH) at diagnosis were evaluated and cutoff values were determined by the maximum log-rank statistic method. The multivariate analysis was performed using Cox proportional hazards regression to identify the independent prognostic factors associated with overall survival (OS). All estimated survival rates were conducted with Kaplan-Meier method.

RESULTS

Median survival and progression time in the cohort were 38.2 and 13.9 months, respectively. The univariable analysis showed that male, number of metastatic sites ≥ 4, presence of liver, serum LDH ≥ 229, SUVmax-M ≥ 10, SUVmax-M-sum ≥ 10, and SUVmax-M-mean ≥ 8.8 were significant prognostic factors. Five variables were identified after LASSO regression and entered into the multivariate analysis. Furthermore, liver involvement (P = 0.039), elevated LDH (≥ 229) (P = 0.05) and higher SUVmax-M (≥ 10) (P = 0.004) were significantly associated with worse OS.

CONCLUSION

The high SUVmax of metastatic lesions (≥ 10), liver involvement, and elevated serum LDH (≥ 229) at diagnosis could independently predict poor survival for de novo mNPC patients treated with palliative chemotherapy following LRRT.

Benefit of [18F] FDG PET/CT in the diagnosis and salvage treatment of recurrent nasopharyngeal carcinoma

PURPOSE

To compare PET/CT, MRI and ultrasonography in detecting recurrence of nasopharyngeal carcinoma and identify their benefit in staging, contouring and overall survival (OS).

METHODS

Cohort A included 1453 patients with or without histopathology-confirmed local recurrence, while cohort B consisted of 316 patients with 606 histopathology-confirmed lymph nodes to compare the sensitivities and specificities of PET/CT, MRI and ultrasonography using McNemar test. Cohorts C and D consisted of 273 patients from cohort A and 267 patients from cohort B, respectively, to compare the distribution of PET/CT-based and MRI-based rT-stage and rN-stage and the accuracy of rN-stage using McNemar test. Cohort E included 30 random patients from cohort A to evaluate the changes in contouring with or without PET/CT by related-samples T test or Wilcoxon rank test. The OS of 61 rT3-4N0M0 patients staged by PET/CT plus MRI (cohort F) and 67 MRI-staged rT3-4N0M0 patients (cohort G) who underwent similar salvage treatment were compared by log-rank test and Cox regression.

RESULTS

PET/CT had similar specificity to MRI but higher sensitivity (93.9% vs. 79.3%, P < 0.001) in detecting local recurrence. PET/CT, MRI and ultrasonography had comparable specificities, but PET/CT had greater sensitivity than MRI (90.9% vs. 67.6%, P < 0.001) and similar sensitivity to ultrasonography in diagnosing lymph nodes. According to PET/CT, more patients were staged rT3-4 (82.8% vs. 68.1%, P < 0.001) or rN + (89.9% vs. 69.3%, P < 0.001), and the rN-stage was more accurate (90.6% vs. 73.8%, P < 0.001). Accordingly, the contours of local recurrence were more precise (median Dice similarity coefficient 0.41 vs. 0.62, P < 0.001) when aided by PET/CT plus MRI. Patients staged by PET/CT plus MRI had a higher 3-year OS than patients staged by MRI alone (85.5% vs. 60.4%, P = 0.006; adjusted HR = 0.34, P = 0.005).

CONCLUSION

PET/CT more accurately detected and staged recurrence of nasopharyngeal carcinoma and accordingly complemented MRI, providing benefit in contouring and OS.

Nomogram to Predict Long-Term Overall Survival and Cancer-Specific Survival of Radiotherapy Patients with Nasopharyngeal Carcinoma

Objective

To establish and validate a nomogram to predict the overall survival (OS) and cancer-specific survival (CSS) in patients with nasopharyngeal carcinoma (NPC) receiving radiotherapy by integrating multiple independent prognostic factors.

Materials and Methods

Data from 5663 patients with NPC who received definite radiotherapy between 2004 and 2018 were included and divided into training and validation cohorts. Univariate and multivariate Cox regression analyses were performed to determine the independent prognostic factors of patients with NPC after radiotherapy. Thereafter, the predictive accuracy of the nomogram model was evaluated.

Results

Age, race, marital status, pathological type, tumor size, T stage, N stage, M stage, American Joint Committee on Cancer stage, and chemotherapy were independent factors affecting the prognosis of patients with NPC receiving radiotherapy. Nomograms with a concordance index of 0.726 (95% confidence interval (CI): 0.675-0.777) and 0.732 (95% CI: 0.680-0.785) were able to predict OS and CSS, respectively. The area under the curve showed excellent predictive performance. Additionally, the calibration curve indicated that the predicted survival rate was consistent with the actual survival rate, and the decision curve indicated its clinical value. The established risk stratification system was able to accurately stratify patients receiving radiotherapy for NPC into three risk subgroups with significant differences in prognosis (P < 0.05).

Conclusions

The constructed nomogram had good prognostic performance and could be used as an effective tool to evaluate the prognosis of patients with NPC after radiotherapy. This nomogram could be further used to guide clinical decisions and personalized treatment plans.

International recommendations for plasma Epstein-Barr virus DNA measurement in nasopharyngeal carcinoma in resource-constrained settings: lessons from the COVID-19 pandemic

The effects of the COVID-19 pandemic continue to constrain health-care staff and resources worldwide, despite the availability of effective vaccines. Aerosol-generating procedures such as endoscopy, a common investigation tool for nasopharyngeal carcinoma, are recognised as a likely cause of SARS-CoV-2 spread in hospitals. Plasma Epstein-Barr virus (EBV) DNA is considered the most accurate biomarker for the routine management of nasopharyngeal carcinoma. A consensus statement on whether plasma EBV DNA can minimise the need for or replace aerosol-generating procedures, imaging methods, and face-to-face consultations in managing nasopharyngeal carcinoma is urgently needed amid the current pandemic and potentially for future highly contagious airborne diseases or natural disasters. We completed a modified Delphi consensus process of three rounds with 33 international experts in otorhinolaryngology or head and neck surgery, radiation oncology, medical oncology, and clinical oncology with vast experience in managing nasopharyngeal carcinoma, representing 51 international professional societies and national clinical trial groups. These consensus recommendations aim to enhance consistency in clinical practice, reduce ambiguity in delivering care, and offer advice for clinicians worldwide who work in endemic and non-endemic regions of nasopharyngeal carcinoma, in the context of COVID-19 and other airborne pandemics, and in future unexpected settings of severe resource constraints and insufficiency of personal protective equipment.

The role of PET/CT in radiotherapy for nasopharyngeal carcinoma

Radiotherapy has already been developed as the standard of care for patients with nasopharyngeal carcinoma (NPC), and precision staging, target volume delineation, prognosis prediction, and post-treatment surveillance are essential in the management of NPC. Positron emission tomography/computed tomography (PET/CT) is increasingly recognized as an imaging modality to guide precision radiotherapy in these areas. The feasibility and efficacy of 18F-FDG PET/CT have been confirmed in tumor diagnosis, treatment planning, prognosis, surveillance, and assessment. Coupled with the capability of revealing tumor metabolic information, 18F-FDG PET/CT is more accurate in identifying primary lesions and metastases of NPC than other conventional imaging methods including CT and MRI and shows the independently diagnostic and prognostic value for radiotherapy. However, 18F-FDG has limitations due to its physiological distribution in brain tissue and increasing uptake in post-radiation inflammation. Novel PET radiotracers including FAPI, NaF, CHO, and FLT are explored as alternatives with potential superiority for radiotherapy in NPC. In this review, we summarized the evolving role of PET/CT in the management of radiotherapy in NPC patients, aiming to facilitate precision radiotherapy from a molecular imaging aspect.