Updates on MR imaging and 18F-FDG PET/CT imaging in nasopharyngeal carcinoma

Utility of interim apparent diffusion coefficient value in predicting treatment response among patients with locally advanced cervical cancer treated with radiotherapy

Background

For locally advanced cervical cancer (LACC), treatment response to radiotherapy (RT) can vary significantly even among those with the same stage classification of International Federation of Gynecology and Obstetrics (FIGO). This study investigated the value of ADC metric for forecasting end-of-treatment outcomes in LACC patients referred for RT.

Methods

Eighty patients with pathologically confirmed cervical squamous cell carcinoma with (SCC) were included in the research. Abdominal or pelvic MRI scans were conducted at least three times for all participants: before RT, three weeks after beginning of RT and approximately two months after RT was finalized. Calculated apparent diffusion coefficient (ADC) values of the LACC include: pre-ADC, interim-ADC, ΔADC and Δ%ADC. Based on Response Evaluation Criteria in Solid Tumors (RECIST) 1.1, subjects were calculated and subsequently categorized into good responders group (complete response) and poor responders group (progressive disease, stable disease or partial response).

Results

Compared to good-responders, subjects of poor-responder group showed significantly lower values of interim-ADC, ΔADC, and Δ%ADC (all P < 0.05). To distinguish between good and poor responders, the optimal cutoff values of interim-ADC, ΔADC, and Δ%ADC were determined to be 1.067 × 10-3 mm2/sec, 0.209 × 10-3 mm2/sec, and 30.74 % using the ROC curve, with corresponding sensitivities of 83.78 %, 86.49 %, 75.68 %, and specificities of 88.37 %, 86.49 %, 75.68 %, respectively. Multivariate logistic regression revealed that the baseline tumor diameter and interim-ADC were significant prognostic factors for treatment response with an odds ratio (OR) of 0.105 (95 % confidence interval [95 % CI] 0.018-0.616) for baseline tumor diameter and 42.896 (95 % CI 8.205-224.262) for interim-ADC.

Conclusion

The interim-ADC value and baseline tumor diameter surfaced as possible indicative factors for predicting the response to RT in patients with LACC.

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.

Establishing subdivisions of M1 stage nasopharyngeal carcinoma based on decision tree classification: A multicenter retrospective study

OBJECTIVES

To meet the demand for personalized treatment, effective stratification of patients with metastatic nasopharyngeal carcinoma (mNPC) is essential. Hence, our study aimed to establish an M1 subdivision for prognostic prediction and treatment planning in patients with mNPC.

MATERIALS AND METHODS

This study included 1239 patients with mNPC from three medical centers divided into the synchronous mNPC cohort (smNPC, n = 556) to establish an M1 stage subdivision and the metachronous mNPC cohort (mmNPC, n = 683) to validate this subdivision. The primary endpoint was overall survival. Univariate and multivariate Cox analyses identified covariates for the decision-tree model, proposing an M1 subdivision. Model performance was evaluated using time-dependent receiver operating characteristic curves, Harrell's concordance index, calibration plots, and decision curve analyses.

RESULTS

The proposed M1 subdivisions were M1a (≤5 metastatic lesions), M1b (>5 metastatic lesions + absent liver metastases), and M1c (>5 metastatic lesions + existing liver metastases) with median OS of 34, 22, and 13 months, respectively (p < 0.001). This M1 subdivision demonstrated superior discrimination (C-index = 0.698; 3-year AUC = 0.707) and clinical utility over those of existing staging systems. Calibration curves exhibited satisfactory agreement between predictions and actual observations. Internal and mmNPC cohort validation confirmed the robustness. Survival benefits from local metastatic treatment were observed in M1a, while immunotherapy improved survival in patients with M1b and M1c disease.

CONCLUSION

This novel M1 staging strategy provides a refined approach for prognostic prediction and treatment planning in patients with mNPC, emphasizing the potential benefits of local and immunotherapeutic interventions based on individualized risk stratification.

Radiomics-based lymph nodes prognostic models from three MRI regions in nasopharyngeal carcinoma

Accurate prediction of the prognosis of nasopharyngeal carcinoma (NPC) is important for treatment. Lymph nodes metastasis is an important predictor for distant failure and regional recurrence in patients with NPC. Traditionally, subjective radiological evaluation increases concerns regarding the accuracy and consistency of predictions. Radiomics is an objective and quantitative evaluation algorithm for medical images. This retrospective analysis was conducted based on the data of 729 patients newly diagnosed with NPC without distant metastases to evaluate the performance of radiomics pretreatment using magnetic resonance imaging (MRI)-determined metastatic lymph nodes models to predict NPC prognosis with three delineation methods. Radiomics features were extracted from all lymph nodes (ALN), largest lymph node (LLN), and largest slice of the largest lymph node (LSLN) to generate three radiomics signatures. The radiomics signatures, clinical model, and radiomics-clinic merged models were developed in training cohort for predicting overall survival (OS). The results showed that LSLN signature with clinical factors predicted OS with high accuracy and robustness using pretreatment MR-determined metastatic lymph nodes (C-index [95 % confidence interval]: 0.762[0.760-0.763]), providing a new tool for treatment planning in NPC.

Predicting Teeth Extraction after Concurrent Chemoradiotherapy in Locally Advanced Nasopharyngeal Cancer Patients Using the Novel GLUCAR Index

To evaluate the value of the newly created GLUCAR index in predicting tooth extraction rates after concurrent chemoradiotherapy (C-CRT) in locally advanced nasopharyngeal carcinomas (LA-NPCs). Methods: A total of 187 LA-NPC patients who received C-CRT were retrospectively analyzed. The GLUCAR index was defined as 'GLUCAR = (Fasting Glucose × CRP/Albumin Ratio) by utilizing measures of glucose, C-reactive protein (CRP), and albumin obtained on the first day of C-CRT. Results: The optimal GLUCAR cutoff was 31.8 (area under the curve: 78.1%; sensitivity: 70.5%; specificity: 70.7%, Youden: 0.412), dividing the study cohort into two groups: GLUCAR ˂ 1.8 (N = 78) and GLUCAR ≥ 31.8 (N = 109) groups. A comparison between the two groups found that the tooth extraction rate was significantly higher in the group with a GLUCAR ≥ 31.8 (84.4% vs. 47.4% for GLUCAR ˂ 31.8; odds ratio (OR):1.82; p < 0.001). In the univariate analysis, the mean mandibular dose ≥ 38.5 Gy group (76.5% vs. 54.9% for <38.5 Gy; OR: 1.45; p = 0.008), mandibular V55.2 Gy group ≥ 40.5% (80.3 vs. 63.5 for <40.5%, p = 0.004, OR; 1.30), and being diabetic (71.8% vs. 57.9% for nondiabetics; OR: 1.23; p = 0.007) appeared as the additional factors significantly associated with higher tooth extraction rates. All four characteristics remained independent predictors of higher tooth extraction rates after C-CRT in the multivariate analysis (p < 0.05 for each). Conclusions: The GLUCAR index, first introduced here, may serve as a robust new biomarker for predicting post-C-CRT tooth extraction rates and stratifying patients according to their tooth loss risk after treatment.

Pretreatment dual-energy CT for predicting early response to induction chemotherapy and survival in nasopharyngeal carcinoma

OBJECTIVES

To evaluate the predictive performance of pretreatment dual-energy CT (DECT) for early response to induction chemotherapy and survival in nasopharyngeal carcinoma (NPC).

METHODS

In this retrospective study, 56 NPC patients who underwent pretreatment DECT scans with posttreatment follow-up were enrolled. The DECT-derived normalised iodine concentration (nIC), effective atomic number (Zeff), 40-180 keV (20 keV interval), and Mix-0.3 value of the tumour lesions were measured to predict the early response to induction chemotherapy and survival in nasopharyngeal carcinoma. The Mann‒Whitney U test, ROC analysis, Kaplan‒Meier method with log-rank test, and Cox proportional hazards model were performed to evaluate the predictive performance of DECT parameters, respectively.

RESULTS

Among all DECT-derived parameters, ROC analysis showed the predictive performances of nIC and Zeff values for early objective response to induction chemotherapy (AUCs of 0.803 and 0.826), locoregional failure-free survival (AUCs of 0.786 and 0.767), progression-free survival (AUCs of 0.856 and 0.731) and overall survival (AUCs of 0.765 and 0.799) in NPC patients, respectively (all p < 0.05). Moreover, multivariate analysis showed that a high nIC value was an independent predictor of poor survival in NPC. In addition, survival analysis indicated that NPC patients with higher nIC values in primary tumours tend to have lower 5-year locoregional failure-free survival, progression-free survival and overall survival rates than those with lower nIC values.

CONCLUSIONS

DECT-derived nIC and Zeff values can predict early response to induction chemotherapy and survival in NPC; in particular, a high nIC value is an independent predictive factor of poor survival in NPC.

CLINICAL RELEVANCE STATEMENT

Preoperative dual-energy computed tomography may provide predictive value for early response and survival outcomes in patients with nasopharyngeal carcinoma, and facilitate their clinical management.

KEY POINTS

• Pretreatment dual-energy computed tomography helps to predict early response to therapy and survival in NPC. • NIC and Zeff values derived from dual-energy computed tomography can predict early objective response to induction chemotherapy and survival in NPC. • A high nIC value is an independent predictive factor of poor survival in NPC.

ACR Appropriateness Criteria® Staging and Post-Therapy Assessment of Head and Neck Cancer

Imaging of head and neck cancer at initial staging and as part of post-treatment surveillance is a key component of patient care as it guides treatment strategy and aids determination of prognosis. Head and neck cancer includes a heterogenous group of malignancies encompassing several anatomic sites and histologies, with squamous cell carcinoma the most common. Together this comprises the seventh most common cancer worldwide. At initial staging comprehensive imaging delineating the anatomic extent of the primary site, while also assessing the nodal involvement of the neck is necessary. The treatment of head and neck cancer often includes a combination of surgery, radiation, and chemotherapy. Post-treatment imaging is tailored for the evaluation of treatment response and early detection of local, locoregional, and distant recurrent tumor. Cross-sectional imaging with CT or MRI is recommended for the detailed anatomic delineation of the primary site. PET/CT provides complementary metabolic information and can map systemic involvement. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Involved site radiation therapy in stage I-III nasopharyngeal carcinoma with limited lymph node burden (ISRT-NPC) or elective region irradiation: a study protocol for a multicenter non-inferiority randomized controlled phase III clinical trial

BACKGROUND

Current radiotherapy guidelines and consensus statements uniformly recommend elective region irradiation (ERI) as the standard strategy for nasopharyngeal carcinoma (NPC). However, given the scarcity of skip-metastasis, the improved assessment accuracy of nodal involvement, and the striking advancements in chemotherapy for NPC, a one-fits-all delineation scheme for clinical target volumes of the nodal region (CTVn) may not be appropriate anymore, and modifications of the CTVn delineation strategy may be warranted. Involved site irradiation (ISI) covering merely the initially involved nodal site and potential extranodal extension has been confirmed to be as effective as ERI with decreased radiation-related toxicities in some malignancies, but has not yet been investigated in NPC. This study aims to compare the regional control, survival outcomes, radiation-related toxicities, and quality of life (QoL) of ISI with conventional ERI in NPC patients with a limited nodal burden.

METHODS

ISRT-NPC is a prospective, multicenter, open-label, noninferiority, phase III randomized controlled trial. A total of 414 patients will be randomly assigned in a 1:1 ratio to receive ISI or ERI. Randomization will be stratified by institution scale and N stage. Generally, in the ISI group, the high-risk CTV1 (dose: 60 Gy) includes a 1-cm expansion of the positive LN as well as the VIIa and the retrostyloid space above the bilateral transverse process of the atlantoaxial spine (C1), regardless of N status. The low-risk CTV2 (dose: 50 Gy) covers the cervical nodal region with a 3-cm caudal expansion below the transverse process of C1 for N0 disease and a 3-cm expansion below the positive LN for positive LNs.

DISCUSSION

The results of this trial are expected to confirm that ISI is a non-inferior strategy to ERI in stage I-III patients with low LN burden, enabling the minimization of treatment-related toxicity and improvement of long-term QoL without compromising regional control.

TRIAL REGISTRATION

ClinicalTrails.gov, NCT05145660. Registered December 6, 2021.

Tumor microenvironment and fibroblast activation protein inhibitor (FAPI) PET: developments toward brain imaging

Fibroblast activation protein (FAP) is a type-II membrane bound glycoprotein specifically expressed by activated fibroblasts almost exclusively in pathological conditions including arthritis, fibrosis and cancer. FAP is overexpressed in cancer-associated fibroblasts (CAFs) located in tumor stroma, and is known to be involved in a variety of tumor-promoting activities such as angiogenesis, proliferation, resistance to chemotherapy, extracellular matrix remodeling and immunosuppression. In most cancer types, higher FAP expression is associated with worse clinical outcomes, leading to the hypothesis that FAP activity is involved in cancer development, cancer cell migration, and cancer spread. Recently, various high selectivity FAP inhibitors (FAPIs) have been developed and subsequently used for positron emission tomography (PET) imaging of different pathologies. Considering the paucity of widely available and especially mainstream reliable radioligands in brain cancer PET imaging, and the poor survival rates of patients with certain types of brain cancer such as glioblastoma, FAPI-PET represents a major development in enabling the detection of small primary or metastatic lesions in the brain due to its biological characteristics and low background accumulation. In this work, we aim to summarize the potential avenues for use of FAPI-PET, from the basic biological processes to oncologic imaging and with a main focus on brain imaging.

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.

Survival effect of pretreatment FDG-PET-CT on nasopharyngeal cancer

BACKGROUND/PURPOSE

Accurate staging is the first step for optimal treatment selection in patients with nasopharyngeal carcinoma (NPC). In this propensity-score-matched, population-based cohort study, we investigated the survival effects of pretreatment 8-fluorodeoxyglucose positron emission tomography-computed tomography (¹⁸FDG-PET-CT) on patients with NPC.

METHODS

We included patients with stage I-IVA NPC receiving radiotherapy or concurrent chemoradiotherapy and categorized them into two 1:1 propensity score-matched groups according to whether or not they underwent pretreatment ¹⁸FDG-PET-CT and compared their outcomes.

RESULTS

Of the 10,756 patients, propensity score matching yielded 4366 patients in each group. According to multivariable Cox regression analyses, the most prominent correlation between pretreatment ¹⁸FDG-PET-CT and all-cause death was observed in patients with stage II NPC (adjusted hazard ratio [aHR], 0.77; 95% confidence interval [CI], 0.60-0.90; P = .0433), followed by patients with stage III NPC (aHR, 0.81; 95% CI, 0.69-0.94; P = .0071) and patients with stage IVA NPC (aHR, 0.88; 95% CI, 0.79-0.97; P = .0091). This association was not significant in patients with stage I NPC (aHR, 1.20; 95% CI, 0.75-1.93; P = .4426).

CONCLUSION

Pretreatment ¹⁸FDG-PET-CT is associated with longer survival in patients with clinical stage II-IVA NPC but not in stage I NPC.

Pretreatment [18F]FDG PET/CT and MRI in the prognosis of nasopharyngeal carcinoma

OBJECTIVE

The present study aimed to assess the prognostic interest of metabolic and anatomic parameters derived from 2-deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography/computed tomography ([¹⁸F]FDG PET/CT) and head and neck magnetic resonance imaging (HN-MRI) for better management of nasopharyngeal carcinoma (NPC).

METHODS

In this study, pre-treatment [¹⁸F]FDG PET/CT and HN-MRI parameters of NPC patients diagnosed between January 2017 and December 2018, were prospectively investigated. Correlation between those parameters and 4-year patient's survival outcomes was evaluated using Kaplan-Meier and Cox-regression analyses.

RESULTS

Our results revealed a significant association between pre-treatment nodal-maximum standardized uptake value (N-SUV max) and N categories (p = 0.01), between pre-treatment node-to-tumor SUV ratio (NTR) and both tumor size (p = 0.01) and N categories (p = 0.009), as well as between metabolic tumor volume (MTV) and both tumor size and NPC overall stage (p < 0.000). In multivariate analyses, pre-treatment N-SUV max, NTR and MTV were significant independent predictors of overall survival, distant metastasis-free survival, and progression-free survival (PFS) (p < 0.05). N-SUV max and MTV were also found to be significant independent predictors of loco-regional recurrence-free survival (p < 0.05), whereas HN-MRI detection of skull-base bone invasion was an independent factor associated with worse PFS in NPC (p = 0.03).

CONCLUSIONS

The present study highlights N-SUV max, NTR and MTV derived from [¹⁸F]FDG PET/CT, and skull-base bone invasion defined by HN-MRI, as promising metabolic and anatomic prognosis biomarkers for NPC.

Utility of diffusion-weighted magnetic resonance imaging in predicting the treatment response of nasopharyngeal carcinoma

OBJECTIVE

Predicting the treatment response in patients with nasopharyngeal carcinoma (NPC) is challenging. This study evaluated the utility of diffusion-weighted imaging (DWI) in predicting the treatment response in patients with NPC.

METHODS

We prospectively enrolled 33 patients with newly diagnosed NPC who underwent magnetic resonance imaging with the propeller DWI and apparent diffusion coefficient (ADC) map before and at 5 weeks after chemoradiation. The following ADC values of the primary tumor were calculated: pre-treatment ADC (pre-ADC), pre-treatment ADC ratio (pre-ADC ratio), ADC change (▵ADC), ADC change ratio (▵ADC ratio), and percentage of ADC change (▵%ADC). The correlations between these parameters and treatment outcomes were explored, and the patients were classified as good responders (complete response) and poor responders (stable disease, partial response, or progressive disease) based on the Response Evaluation Criteria in Solid Tumors, version 1.1.

RESULTS

The ▵ADC, ▵ADC ratio, and ▵%ADC were significantly lower in the poor-responder group (n = 12) than in the good-responder group (n = 21; p = 0.001, p = 0.002, and p = 0.004, respectively). There was no significant difference between groups in the pre-ADC and pre-ADC ratios (p = 0.602 and p = 0.685, respectively). The optimal ▵ADC, ▵ADC ratio, and ▵%ADC cutoff values for predicting poor response were >0.65 mm²/sec, 0.28, and 60%, respectively (sensitivity: 83.3%, 75%, and 83.3%; specificity: 71.4%, 85.7%, and 71.4%, respectively).

CONCLUSION

The ▵ADC, ▵ADC ratio, and ▵%ADC obtained during the pre-treatment and mid-treatment periods could be potential biomarkers for predicting treatment response in patients with NPC.

The Chinese Society of Clinical Oncology (CSCO) clinical guidelines for the diagnosis and treatment of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant epithelial tumor originating in the nasopharynx and has a high incidence in Southeast Asia and North Africa. To develop these comprehensive guidelines for the diagnosis and management of NPC, the Chinese Society of Clinical Oncology (CSCO) arranged a multi‐disciplinary team comprising of experts from all sub‐specialties of NPC to write, discuss, and revise the guidelines. Based on the findings of evidence‐based medicine in China and abroad, domestic experts have iteratively developed these guidelines to provide proper management of NPC. Overall, the guidelines describe the screening, clinical and pathological diagnosis, staging and risk assessment, therapies, and follow‐up of NPC, which aim to improve the management of NPC.

Biopsy of cervical lymph node does not impact the survival of nasopharyngeal carcinoma

Purpose

The optimal practice regarding cervical lymph node biopsy (CLNB) remains to be defined to provide the best clinical management in nasopharyngeal carcinoma (NPC). This study aimed to investigate the effect of CLNB on the survival of NPC patients.

Methods

Patients diagnosed with NPC from 2004 to 2015 were identified using the Surveillance, Epidemiology, and End Results database. Multivariate logistic regression, Kaplan–Meier method, Cox proportional hazards regression analysis, and propensity score matching (PSM) were used to determine the factors associated with CLNB and prognostic effect of CLNB of NPC.

Results

We included 1903 patients in this study. There were 321 (16.9%) and 1582 (83.1%) patients with and without CLNB, respectively. The percentage of CLNB was 19.4% in 2004 and was decreased to 8.6% in 2015 (p = 0.044). Patients diagnosed in later years (p = 0.008), older age (p < 0.001), Chinese (p = 0.002), advanced tumor stage (p < 0.001), and early nodal stage (p = 0.003) were less likely to receive additional CLNB. In patients who received additional CLNB, the 5‐years NPC‐specific survival (NPCSS) was 83.6%, which was similar to patients without CLNB (80.1%, p = 0.159). In addition, a similar 5‐years NPCSS was found between those receiving biopsy or aspiration of regional lymph node and those receiving lymph node resection (p = 0.584). There were 187 pairs of patients who were completely matched using PSM, the multivariate prognostic analyses indicated that the receipt of CLNB was not associated with an inferior outcome in the PSM cohort (p = 0.349). Similar results were found after stratification by the year of diagnosis, race/ethnicity, and histology.

Conclusion

Additional CLNB is not associated with an inferior survival outcome in NPC. Our study provides a reference for the clinical practice of NPC.

High Pretreatment Platelet-to-Albumin Ratio Predicts Poor Survival Results in Locally Advanced Nasopharyngeal Cancers Treated with Chemoradiotherapy

Purpose

In a lack of similar research, we assessed the prognostic utility of pretreatment platelet-to-albumin ratio (PAR) in locally advanced nasopharyngeal carcinoma (LANPC) patients managed with concurrent chemoradiotherapy (CCRT).

Patients and Methods

Present retrospective analysis included a sum of 128 consecutively treated LANPC patients who underwent cisplatinum-based radical CCRT. Availability of an ideal pretreatment PAR cutoff that may stratify the study population into two cohorts with significantly distinct survival outcomes was sought by utilizing the receiver operating characteristic (ROC) curve analysis. The primary and secondary endpoints were overall survival (OS) and progression-free survival (PFS), respectively.

Results

A rounded 5.2 [area under the curve (AUC): 68.9%; sensitivity: 67.4%; and specificity: 65.2%] value was identified as the ideal PAR cutoff that grouped patients into two gatherings [PAR≥5.2 (N=60) versus <5.2 (N=68)]. The median follow-up duration was 86.4 months (range: 9-147). Kaplan-Meier comparisons between the two PAR groups revealed significantly diminished median PFS (69.4 versus 106.8 months for PAR<5.2; P< 0.012) and OS (88.3 versus not reached yet for PAR<5.2; P= 0.023) for the PAR ≥ 5.2 group. The results of multivariate analyses affirmed the pretreatment PAR≥5.2 as an independent prognostic factor that indicates diminished PFS (P= 0.016) and OS (P= 0.019) together with the respective N_2-3 nodal stage (versus N_0-1; P<0.05 for PFS and OS, respectively) and weight loss >5% at past six months (≤5%; P<0.05 for PFS and OS, respectively).

Conclusion

The results of the current retrospective analysis provided a robust and independent adverse prognostic value for pretreatment PAR ≥ 5.2 in terms of median and long-term PFS and OS outcomes in LA-NPC patients this patient group treated with conclusive CCRT.

Using arterial spin labeling blood flow and its histogram analysis to distinguish early-stage nasopharyngeal carcinoma from lymphoid hyperplasia

ABSTRACT

To investigate the feasibility of arterial spin labeling (ASL) blood flow (BF) and its histogram analysis to distinguish early-stage nasopharyngeal carcinoma (NPC) from nasopharyngeal lymphoid hyperplasia (NPLH).Sixty-three stage T1 NPC patients and benign NPLH patients underwent ASL on a 3.0-T magnetic resonance imaging system. BF histogram parameters were derived automatically, including the mean, median, maximum, minimum, kurtosis, skewness, and variance. Absolute values were obtained for skewness and kurtosis (absolute value of skewness [AVS] and absolute value of kurtosis [AVK], respectively). The Mann-Whitney U test, receiver operating characteristic curve, and multiple logistic regression models were used for statistical analysis.The mean, maximum, and variance of ASL BF values were significantly higher in early-stage NPC than in NPLH (all P < 0.0001), while the median and AVK values of early-stage NPC were also significantly higher than those of NPLH (all P < 0.001). No significant difference was found between the minimum and AVS values in early-stage NPC compared with NPLH (P = 0.125 and P = 0.084, respectively). The area under the curve (AUC) of the maximum was significantly higher than those of the mean and median (P < 0.05). The AUC of variance was significantly higher than those of the other parameters (all P < 0.05). Multivariate analysis showed that variance was the only independent predictor of outcome (P < 0.05).ASL BF and its histogram analysis could distinguish early-stage NPC from NPLH, and the variance value was a unique independent predictor.

A head-to-head comparison of 68Ga-DOTA-FAPI-04 and 18F-FDG PET/MR in patients with nasopharyngeal carcinoma: a prospective study

PURPOSE

To conduct a head-to-head comparison of the diagnostic ability of ⁶⁸Ga-DOTA-FAPI-04 (⁶⁸Ga-FAPI) and ¹⁸F-FDG PET/MR in nasopharyngeal carcinoma (NPC) patients.

METHODS

Patients diagnosed with NPC were prospectively enrolled. All patients underwent head-and-neck ⁶⁸Ga-FAPI PET/MR and ¹⁸F-FDG PET/MR within 1 week. Primary tumor, lymph node numbers, and tracer uptake were compared by SUVmax and visual evaluation. The primary tumor volumes derived from ⁶⁸Ga-FAPI, ¹⁸F-FDG PET, and MRI were also compared.

RESULTS

Fifteen patients were enrolled from June to August 2020. Both ⁶⁸Ga-FAPI and ¹⁸F-FDG PET had 100% detection rate of the primary tumor. The ⁶⁸Ga-FAPI SUVmax of primary tumors (13.87 ± 5.13) was lower than that of ¹⁸F-FDG (17.73 ± 6.84), but the difference was not significant (p = 0.078). Compared with ¹⁸F-FDG, ⁶⁸Ga-FAPI PET improved the delineation of skull-base invasion in eight out of eight patients and intracranial invasion in four out of four patients. When 25%SUVmax of ⁶⁸Ga-FAPI or 20%SUVmax of ¹⁸F-FDG was utilized as a threshold for determining tumor volume, it was highly consistent with MRI. ¹⁸F-FDG PET detected much more positive lymph nodes than ⁶⁸Ga-FAPI (100 vs 48). The SUVmax of 48 paired lymph nodes was significantly lower on ⁶⁸Ga-FAPI than ¹⁸F-FDG (8.67 ± 3.88 vs 11.79 ± 6.17, p < 0.001). Additionally, ⁶⁸Ga-FAPI further detected four highly suspected small, distant metastases in three patients. Compared with ¹⁸F-FDG, ⁶⁸Ga-FAPI changed overall staging in six of fifteen patients, with three patients being up-staged, and three down-staged.

CONCLUSION

⁶⁸Ga-FAPI outperforms ¹⁸F-FDG in delineating the primary tumor and detecting suspected distant metastases, particularly in the evaluation of skull-base and intracranial invasion, suggesting ⁶⁸Ga-FAPI hybrid PET/MR has the potential to serve as a single-step staging modality for patients with NPC. However, its value regarding lymph node and distant metastases evaluation needs further study.

TRIAL REGISTRATION

NCT04554719. Registered September 8, 2020 - retrospectively registered, http://clinicaltrails.gov/show/NCT04554719.

A Rare Case of a Congenital Nasopharyngeal Ganglioglioma With Dyspnea in a 1-Month-Old Male Infant: A Case Report

Background: A ganglioglioma (GG), a tumor with both neuronal and astrocytic components, rarely occurs outside the central nervous system. Case Summary: We present the first reported case of a 1-month-old male with a congenital nasopharyngeal GG, nasal congestion, and dyspnea; we include the operative video. Magnetic resonance imaging was used to explore whether the tumor communicated with the intracranial space. We used an endoscopic plasma technique to ensure complete tumor resection. This afforded a good visual field, endoscopic magnification, and good hemostasis. Conclusions: We report a rare case of a nasopharyngeal GG triggering nasal congestion and dyspnea in a 1-month-old male, and report our experience with the treatment of nasopharyngeal GG and similar diseases.

Nasopharyngeal carcinoma perfusion MRI: Comparison of arterial spin labeling and dynamic contrast-enhanced MRI

To investigate the feasibility of 3D arterial spin labeling (ASL) as an alternative to dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) for the qualitative and quantitative evaluation of nasopharyngeal carcinoma (NPC) perfusion.Fifty-two newly diagnosed NPC patients underwent 3D ASL and DCE-MRI scans on a 3.0-T MRI system. The visual qualitative evaluation of the NPC perfusion level was scored from 0 to 3 (0 = no contrast to normal peripheral soft tissue, 3 = pronounced contrast to normal peripheral soft tissue). The visual evaluation of the NPC outline was scored from 0 to 2 (0 = very vague outline, 2 = clear outline). Comparisons of the ASL-derived blood flow (BF) with the DCE-MRI-derived positive enhancement integral, maximum slope of increase, maximum slope of decrease, and time to peak (TTP) were conducted between NPC and non-NPC areas with independent samples t-tests. The diagnostic performance of these parameters was assessed by receiver operating characteristic curve analysis. The correlations between ASL BF and DCE parameters were assessed by Spearman correlation analysis.There was no difference in the visual scores of the NPC perfusion level between the 2 perfusion methods (P= .963). ASL had a lower visual score for describing the outline of NPC than DCE-MRI (P < .001). The ASL and DCE parameters of the NPC areas were significantly different from those of the non-NPC areas (P < .001). The ASL BF showed the largest area under the receiver operating characteristic curve (AUC) of 0.936 for identifying NPC. When all NPC and non-NPC areas were taken into account, significant correlations were observed between the ASL BF and the DCE parameters positive enhancement integral (r = 0.503, P < .001), maximum slope of increase (r = 0.616, P < .001), maximum slope of decrease (r = 0.380, P < .001), and TTP (r = -0.601, P < .001).3D ASL could reveal the hyperperfusion of NPC in a qualitative and quantitative manner without using contrast agent. Additionally, the ASL BF correlated significantly with the semiquantitative DCE-MRI parameters.

Carcinoma of unknown primary detected by whole-body diffusion-weighted imaging: A case report and review of the literature

Carcinoma of unknown primary accounts for 2%-5% of all head and neck tumors. Identification of the primary site is challenging. We present a case report of a 43-year-old man with metastatic cervical lymphadenopathy for 3 year, and the primary tumor was unknown after routine examinations, including positron emission tomography/computed tomography. Whole-body diffusion-weighted imaging was performed to detect small lesions in the nasopharynx, and a biopsy confirmed the lesions as squamous cell carcinoma. Therefore, the primary tumor site was found in a patient with carcinoma of unknown primary, suggesting that whole-body diffusion-weighted imaging can be very helpful in detecting small occult cancer.

Utility of magnetic resonance imaging in determining treatment response and local recurrence in nasopharyngeal carcinoma treated curatively

Background

To determine the optimal timing of the first Magnetic Resonance Imaging (MRI) scan after curative-intent radiotherapy (RT) for nasopharyngeal carcinoma (NPC), and evaluate the role of MRI in surveillance for locoregional recurrence (LRR).

Methods

Patients with non-metastatic NPC treated radically who had at least one post-treatment MRI (ptMRI) done were included for analysis. ptMRI reports were retrospectively reviewed and categorised as complete response (CR), partial response/residual disease (PR) or indeterminate (ID). Patients with LRR were assessed to determine if initial detection was by MRI or clinical means. Univariable and multivariable Cox proportional hazard regression analysis were performed to identify independent factors associated with CR on ptMRIs.

Results

Between 2013 and 2017, 262 eligible patients were analysed, all treated with Intensity Modulated Radiotherapy (IMRT). Median time from end of RT to the first ptMRI was 93 days (range 32–346). Of the first ptMRIs, 88 (33.2%) were CR, 133 (50.2%) ID, and 44 (16.6%) PR. A second ptMRI was done for 104 (78.2%) of 133 patients with ID status. In this group, 77 (57.9%) of the subsequent MRI were determined to be CR, 21(15.8%) remained ID and 6 (4.5%) PR. T1 tumour stage and AJCC stage I were associated with increased CR rates on first ptMRI on multivariable analysis. ID status was more likely at 75–105 days (3 months +/− 15 days) vs 106–135 days (4 months +/− 15 days) post RT (OR 2.13, 95% CI 1.16–4.12, p = 0.024). LRR developed in 27 (10.1%) patients; 20 (74.1%) were initially detected through MRI, 3 (11.1%) by nasoendoscopy and 2 (7.4%) by PET-CT.

Conclusion

MRI is useful for detecting local recurrence or persistent disease after curative-intent treatment. Most patients will need more than one ptMRI to arrive at a definitive status. The rate of ID ptMRI may be reduced by delaying the first scan to around 4 months post RT.

68Ga-FAPI PET/CT: Tracer Uptake in 28 Different Kinds of Cancer

The recent development of quinoline-based PET tracers that act as fibroblast-activation-protein inhibitors (FAPIs) demonstrated promising preclinical and clinical results. FAP is overexpressed by cancer-associated fibroblasts of several tumor entities. Here, we quantify the tumor uptake on ⁶⁸Ga-FAPI PET/CT of various primary and metastatic tumors to identify the most promising indications for future application. Methods: ⁶⁸Ga-FAPI PET/CT scans were requested by various referring physicians according to individual clinical indications that were considered insufficiently covered by ¹⁸F-FDG PET/CT or other imaging modalities. All PET/CT was performed 1 h after injection of 122-312 MBq of ⁶⁸Ga-FAPI-04. We retrospectively identified 80 patients with histopathologically proven primary tumors or metastases or radiologically unequivocal metastatic lesions of histologically proven primary tumors. Tumor uptake was quantified by SUV_max and SUV_mean (60% isocontour). Results: Eighty patients with 28 different tumor entities (54 primary tumors and 229 metastases) were evaluated. The highest average SUV_max (>12) was found in sarcoma, esophageal, breast, cholangiocarcinoma, and lung cancer. The lowest ⁶⁸Ga-FAPI uptake (average SUV_max < 6) was observed in pheochromocytoma, renal cell, differentiated thyroid, adenoid cystic, and gastric cancer. The average SUV_max of hepatocellular, colorectal, head-neck, ovarian, pancreatic, and prostate cancer was intermediate (SUV 6-12). SUV varied across and within all tumor entities. Because of low background in muscle and blood pool (SUV_max < 2), the tumor-to-background contrast ratios were more than 3-fold in the intermediate and more than 6-fold in the high-intensity uptake group. Conclusion: Several highly prevalent cancers presented with remarkably high uptake and image contrast on ⁶⁸Ga-FAPI PET/CT. The high and rather selective tumor uptake may open up new applications for noninvasive tumor characterization, staging examinations, or radioligand therapy.

Advantage of PET/CT in Target Delineation of MRI-negative Cervical Lymph Nodes In Intensity-Modulated Radiation Therapy Planning for Nasopharyngeal Carcinoma

Introduction: In intensity-modulated radiation therapy (IMRT) planning for nasopharyngeal carcinoma (NPC), cervical lymph nodes (CLNs) that appear negative on magnetic resonance imaging (MRI) scans can be difficult to target. The purpose of this study was to assess the advantage of ¹⁸F-fluorodeoxyglucose positron emission tomography with computed tomography (¹⁸F-FDG PET/CT) for distinguishing MRI-negative CLNs and the effect of ¹⁸F-FDG PET/CT on diagnosis, target delineation, and dose prescription in IMRT planning for NPC.

Methods: Thirty-five NPC patients with 37 MRI-negative CLNs underwent ¹⁸F-FDG PET/CT imaging before treatment. Ultrasonography-guided fine-needle aspiration cytology (USgFNAC) was performed to examine the pathology of CLNs. The ¹⁸F-FDG PET/CT and cytopathological results were compared, and the diagnostic accuracy of ¹⁸F-FDG PET/CT was calculated. The cytopathologically confirmed CLNs were delineated and treated as the gross tumor volume of lymph nodes (denoted as GTVnd).

Results: Nineteen of the 37 MRI-negative CLNs were positive on ¹⁸F-FDG PET/CT, and metastasis was confirmed by USgFNAC in 16 CLNs. Of the remaining 18 ¹⁸F-FDG PET/CT-negative lymph nodes, metastasis was confirmed in one. The diagnostic accuracy, sensitivity, and specificity of ¹⁸F-FDG PET/CT were 89.2%, 94.1%, and 85.0%, respectively. The positive and negative predictive values were 84.2% and 94.4%, respectively. With a median follow-up of 48.3 months, no relapse was observed among the ¹⁸F-FDG PET/CT-positive CLNs with metastasis confirmed by USgFNAC and treated as GTVnd.

Conclusion:¹⁸F-FDG PET/CT had high accuracy, sensitivity, and specificity for distinguishing MRI-negative CLNs. ¹⁸F-FDG PET/CT-positive CLNs could reasonably be categorized as high-risk clinical tumor volume in IMRT planning for NPC.

Intravoxel incoherent motion MR imaging in nasopharyngeal carcinoma: comparison and correlation with dynamic contrast enhanced MR imaging

OBJECTIVES

To compare accuracy and assess agreement between intravoxel incoherent motion (IVIM) magnetic resonance (MR) perfusion-related parameters and quantitative dynamic contrast-enhanced (DCE) MR parameters in nasopharyngeal carcinoma (NPC).

RESULTS

D, f, D*, Ktrans , Kep and Vp were significantly lower in the high stage group while Ve was significantly higher in the high stage group. Optimal cut-off values were: D=0.749 × 10-3 mm2/s; f=0.145; D*=100.401 × 10-3 mm2/s; Ktrans =0.571/min; Kep =0.8196/min; Ve =0.6556 %; Vp =0.0757 %. D* (p=0.001), Ktrans (p<0.001), Ve (p=0.014) were all reliable independent predictors for AJCC staging. IVIM-MR perfusion-related (f, D*) and DCE-MR (Ktrans , Kep , Ve , Vp ) parameters were significantly correlated (p<0.001).

MATERIALS AND METHODS

75 patients with newly diagnosed NPC were prospectively recruited. Diffusion-weighted MR and DCE-MR imaging were performed with respective IVIM (D, f, D*) and DCE (Ktrans , Kep , Ve , Vp ) MR parameters calculated. Patients were stratified into low and high tumor stage groups according to American Joint Committee on Cancer (AJCC) staging for determination of the predictive powers of IVIM-MR and DCE-MR parameters using t-test, ROC curve analyses and multiple logistic regression analysis. Correlation between IVIM-MR perfusion-related and DCE-MR parameters was assessed using Spearman's rank correlation.

CONCLUSION

IVIM-MR perfusion-related and quantitative DCE-MR parameters were significantly correlated in the assessment of NPC and were both reliable independent predictors in the prediction of AJCC staging. IVIM-MR perfusion imaging can be a potential useful non-invasive perfusion imaging tool for clinical use in the assessment of NPC.

Prognostic value of maximum standard uptake value, metabolic tumor volume, and total lesion glycolysis of positron emission tomography/computed tomography in patients with nasopharyngeal carcinoma: A systematic review and meta-analysis

BACKGROUND

The maximal standard uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of positron emission tomography/computed tomography (PET/CT) in patients with nasopharyngeal carcinoma (NPC) perform as new prognostic factors, but the outcomes of the published articles were inconclusive. In this meta-analysis, we evaluated the prognostic value of SUVmax, MTV, and TLG of PET/CT in patients with NPC.

METHODS

Relevant English articles were searched in PubMed and EMBASE. The data of patients and the survival outcomes were extracted. Pooled hazard ratios (HRs) were accounted to assess the prognostic value of the SUVmax, MTV, and TLG.

RESULTS

This meta-analysis combined 10 primary studies including 941 patients with NPC. The combined HRs (95% confidence interval [CI] of higher SUVmax, higher MTV, and higher TLG for event-free survival were 2.33 (95% CI, 1.39-3.91, P = .001), 2.51 (95% CI, 1.61-3.91, P < .0001), and 2.74 (95% CI, 1.91-3.93, P < .00001), respectively. Regarding overall survival, the combined HRs were 2.50 (95%CI, 1.65-3.78, P < .0001) with higher SUVmax, 3.30 (95% CI, 1.92-5.69, P < .0001) with higher MTV and 3.18 (95% CI, 1.70-5.96, P = .0003) with higher TLG.

CONCLUSION

SUVmax, MTV, and TLG were significant prognostic predictors in patients with NPC. And the results suggested that higher SUVmax, MTV, and TLG were associated with worse prognosis.

Whole-body 18F-FDG PET/CT for M staging in the patient with newly diagnosed nasopharyngeal carcinoma: Who needs?

OBJECTIVE

Although whole-body fluorine-18 fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) (¹⁸F-FDG PET/CT) is commonly used for M staging of newly diagnosed nasopharyngeal carcinoma (NPC), some patients may not benefit from this procedure. The present study investigated which patients require this modality for M staging.

METHODS

Whole-body ¹⁸F FDG PET/CT results and clinical data were collected for 264 patients with newly diagnosed NPC. The relationships between distant metastasis and age, gender, pathological type, lesion size, SUVmax-T, T staging, N staging, SUVmax-N and Epstein-Barr virus (EBV) quantity were retrospectively analysed to identify factors associated with increased risk.

RESULTS

Of the 264 patients, only 37 (14.0%) were diagnosed with distant metastasis. Using multiple logistic regression analysis, EBV-positivity (OR=13.1; 95% CI:1.61,106.80), N staging (OR=3.05; 95% CI:1.41,6.63) and T staging (OR=2.16; 95% CI:1.10, 4.24) were significantly related to distant metastasis (all P<0.05). EBV DNA levels≥9000copies/ml, N3 stage and T4 stage were identified as high risk factors. A low risk of distant metastasis was found in patients with 0-1 risk factors and in those with 2 specific risk factors, T3/T4 and N2/N3 staging. Patients with EBV DNA levels ≥9000copies/ml and N3 or T4 staging and those with 3 risk factors had a medium or high risk, with a much higher incidence of distant metastasis (χ²=29.896, P=0.000), and needed a whole-body ¹⁸F FDG PET/CT for M staging.

CONCLUSIONS

Due to the low incidence of distant metastasis, only patients with medium or high risk need to undergo a whole-body scan.

Can Parameters Other than Minimal Axial Diameter in MRI and PET/CT Further Improve Diagnostic Accuracy for Equivocal Retropharyngeal Lymph Nodes in Nasopharyngeal Carcinoma?

Purpose

Minimal axial diameter (MIAD) in magnetic resonance imaging (MRI) was recognized as the most useful parameter in diagnosing lateral retropharyngeal lymph (LRPL) nodes in nasopharyngeal carcinoma (NPC). This study aims to explore the additional nodal parameters in MRI and positron emission tomography–computed tomography for increasing the prediction accuracy.

Materials and Methods

A total of 663 LRPL nodes were retrospectively collected from 335 patients with NPC. The LRPL nodes ascertained on follow-up MRI were considered positive for metastases. First, the optimal cutoff value of each parameter was derived for each parameter. In addition, neural network (NN) nodal evaluation was tested for all combinations of three parameters, namely MIAD, maximal axial diameter (MAAD), and maximal coronal diameter (MACD). The optimal approach was determined through brute force attack, and the results of two methods were compared using a bootstrap sampling method. Second, the mean standard uptake value (NSUVmean) was added as the fourth parameter and tested in the same manner for 410 nodes in 219 patients.

Results

In first and second analysis, the accuracy rate (percentage) for the MIAD was 89.0% (590/663) and 89.0% (365/410), with the optimal cutoff values being 6.1 mm and 6.0 mm, respectively. With the combination of all three and four parameters, the accuracy rate of the NN was 89% (288/332) and 88.8% (182/205), respectively. In prediction, the optimal combinations of the three and four parameters resulted in correct identification of three (accuracy: 593/663, 89.4%) and six additional nodes (371/410, 90.5%), representing 4% (3/73) and 13.3% (6/45) decreases in incorrect prediction, respectively.

Conclusion

NPC LRPL nodes with an MIAD ≥ 6.1 mm are positive. Among nodes with an MIAD < 6.1 mm, if the NSUVmean ≥ 2.6 or MACD ≥ 25 mm and MAAD ≥ 8 mm, the nodes are positive; otherwise, they are negative.

Radiation therapy for nasopharyngeal carcinoma: the predictive value of interim survival assessment

Pretreatment characteristics are suggested as predictive and/or prognostic factors for nasopharyngeal carcinoma (NPC); however, individual tumor radiosensitivities have previously not been considered. As boost planning is recommended for NPC, we performed interim assessments of magnetic resonance (MR) images for boost planning and retrospectively evaluated their predictive value for the survival of NPC patients. Radiation therapy via elective nodal irradiation (median dose: 39.6 Gy) with/without chemotherapy was used to treat 63 NPC patients. Boost irradiation (median total dose: 70 Gy) was performed based on the interim assessment. The largest lymph node (LN) was measured on MR images acquired at the time of interim assessment. The site of first failure was local in 8 (12.7%), regional in 7 (11.1%), and distant in 12 patients (19.0%). All 7 patients with regional failure harbored LNs ≥15 mm at interim assessment. We divided the 63 patients into two groups based on LN size [large (≥15 mm), n = 10 and small (<15 mm), n = 53]. Univariate analysis showed that 5-year overall survival (OS) and cause-specific survival (CSS) rates for large LNs were significantly lower than for small LNs (OS: 12.5% vs 70.5%, P < 0.001 and CSS: 25.0% vs 80.0%, P < 0.001). Multivariate analysis showed that large LNs were a significantly unfavorable factor for both OS (hazard ratio = 4.543, P = 0.002) and CSS (hazard ratio = 6.020, P = 0.001). The results suggest that LN size at interim assessment could predict survival in NPC patients.

The impact of positron emission tomography on primary tumour delineation and dosimetric outcome in intensity modulated radiotherapy of early T-stage nasopharyngeal carcinoma

Background

In intensity modulated radiotherapy (IMRT) of nasopharyngeal carcinoma (NPC), accurate delineation of the gross tumour volume (GTV) is important. Image registration of CT and MRI has been routinely used in treatment planning. With recent development of positron emission tomography (PET), the aims of this study were to evaluate the impact of PET on GTV delineation and dosimetric outcome in IMRT of early stage NPC patients.

Methods

Twenty NPC patients with T1 or T2 disease treated by IMRT were recruited. For each patient, 2 sets of NP GTVs were delineated separately, in which one set was performed using CT and MRI registration only (GTV_CM), while the other set was carried out using PET, CT and MRI information (GTV_CMP). A 9-field IMRT plan was computed based on the target volumes generated from CT and MRI (PTV_CM). To assess the geometric difference between the GTV_CM and GTV_CMP, GTV volumes and DICE similarity coefficient (DSC), which measured the geometrical similarity between the two GTVs, were recorded. To evaluate the dosimetric impact, the D_max, D_min, D_mean and D₉₅ of PTVs were obtained from their dose volume histograms generated by the treatment planning system.

Results

The overall mean volume of GTV_CMP was greater than GTV_CM by 4.4 %, in which GTV_CMP was slightly greater in the T1 group but lower in the T2 group. The mean DSC of the whole group was 0.79 ± 0.05. Similar mean DSC values were also obtained from the T1 and T2 groups separately. The dosimetric parameters of PTV_CM fulfilled the planning requirements. When applying this plan to the PTV_CMP, the average D_min (56.9 Gy) and D₉₅ (68.6 Gy) of PTV_CMP failed to meet the dose requirements and demonstrated significant differences from the PTV_CM (p = 0.001 and 0.016 respectively), whereas the doses to GTV_CMP did not show significant difference with the GTV_CM.

Conclusion

In IMRT of early stage NPC, PET was an important imaging modality in radiotherapy planning so as to avoid underdosing the PTV, although its effect on GTV delineation was not significant. It was recommended that PET images should be included in the treatment planning of NPC patients.

Simultaneous (18)F-FDG-PET/MRI: Associations between diffusion, glucose metabolism and histopathological parameters in patients with head and neck squamous cell carcinoma

OBJECTIVES

To analyze possible associations between functional simultaneous (18)F-FDG-PET/MR imaging parameters and histopathological parameters in head and neck squamous cell carcinoma (HNSCC).

MATERIAL AND METHODS

11 patients (2 female, 9 male; mean age 56.0years) with biopsy-proven primary HNSCC underwent simultaneous (18)F-FDG-PET/MRI with a dedicated head and neck protocol including diffusion weighted imaging. For each tumor, glucose metabolism was estimated with standardized uptake values (SUV) and diffusion restriction was calculated using apparent diffusion coefficients (ADC). The tumor proliferation index was estimated on Ki 67 antigen stained specimens. Cell count, total nucleic area, and average nucleic area were estimated in each case. Pearson's correlation coefficient was used to analyze possible associations between the estimated parameters.

RESULTS

The mean SUVmax value was 24.41±6.51, and SUVmean value 15.01±4.07. Mean values (×10(-3)mm(2)s(-1)) of ADC parameters were as follows: ADCmin: 0.65±0.20; ADCmean: 1.28±0.18; and ADCmax: 2.16±0.35. Histopathological analysis identified the following results: cell count 1069.82±388.66, total nucleic area 150771.09±61177.12μm(2), average nucleic area 142.90±57.27μm(2) and proliferation index 49.09±22.67%. ADCmean correlated with Ki 67 level (r=-0.728, p=0.011) and total nucleic area (r=-0.691, p=0.019) and tended to correlate with average nucleic area (r=-0.527, p=0.096). ADCmax correlated with Ki 67 level (r=-0.633, p=0.036). SUVmax also tended to correlate with average nucleic area (r=0.573, p=0.066). Combined parameter SUVmax/ADCmin correlated with average nucleic area (r=0.627, p=0.039).

CONCLUSION

ADC and SUV values showed significant correlations with different histopathological parameters and can be used as biological markers in HNSCC.

(18)F-FDG Uptake Characteristics in Differentiating Benign from Malignant Nasopharyngeal Lesions in Children

The characteristics of FDG uptake in the physiologic and malignant nasopharynx were investigated in the paper which was correlated with either pathologic findings or clinical follow-up. Three patients had pathologically established nasopharyngeal malignancy. In the 3 nasopharyngeal malignancies, 2 had diffusely and expansively increased FDG uptake, and one had asymmetric uptake. Our results indicated that the difference between adenoid hypertrophy and malignancy is asymmetric or diffusely expansive ¹⁸F-FDG uptake with or without correlating morphologic lesion on diagnostic CT in children under 10 years of age. The typical characteristics of physiologic and inflammatory ¹⁸F-FDG uptake in nasopharynx are symmetrically trapezoid. Diffusely increased nasopharyngeal FDG uptake can be considered physiologic if SUV_max is less than 7.6 but should be carefully assessed by pharyngorhinoscopy if SUV_max is greater than 11 and there is no correlating morphologic lesion on diagnostic CT. The diffusely, expansively increased uptake, and asymmetric uptake in particular, should be considered as malignancy. Further biopsy is especially indicated in patients with retropharyngeal space and bilateral cervical lymph node abnormality but no history of malignancy.

Prognostic value of MRI-derived masticator space involvement in IMRT-treated nasopharyngeal carcinoma patients

OBJECTIVES

This retrospective study reassessed nasopharyngeal carcinoma (NPC) patients treated with intensity-modulated radiation therapy (IMRT), to determine the significance how magnetic resonance imaging (MRI)-derived masticator space involvement (MSI) affected patients' prognosis.

METHODS

One thousand one hundred ninety seven NPC patients who had complete set of MRI and medical records were enrolled. Basing on their MRI findings, the T-categories of tumors were identified according to the seventh edition of American Joint Committee on Cancer staging system, which considers MSI a prognostic indicator for NPCs. Rates of overall survival (OS), local relapse-free survival (LRFS), regional relapse-free survival (RRFS) and distant metastasis-free survival (DMFS) were analyzed by the Kaplan-Meier method, and the Log-Rank test compared their differences. Cox regression analysis was employed to evaluate various prognostic factors systematically. Statistical analyses were conducted with SPSS 18.0 software, P value < 0.05 was considered statistically significant.

RESULTS

Medial pterygoid muscle (MPM) was involved in 283 (23.64 %) cases, of which lateral pterygoid muscle (LPM) was concurrently affected in 181 (15.12 %) and infratemporal fossa (ITF) in 19 (1.59 %). Generally, MSI correlated with an OS, LRFS, and DMFS consistent with a T4-stage diagnosis (P > 0.05). Although different degrees of MSI presented a similar OS and DMFS (P > 0.1), tumors involving LPM had a relatively poorer LRFS than those affected the MPM only (P = 0.027), even for subgroup of patients composed of T3 and T4 classifications (P = 0.035). A tumor involving MPM brought an LRFS consistent with a T2 or T3-stage disease (P > 0.1). If the tumor affected LPM or ITF concurrently, the survival outcomes were more consistent with a T4-stage disease (P > 0.1). Nevertheless, compared to tumor infiltrating MPM, those invading LPM or ITF more frequently spread into other concurrent sites that earned higher T-staging categories. Moreover, multivariate analyses indicated the degree of MSI was a significant prognostic factor for the OS of NPCs (P = 0.036).

CONCLUSIONS

Degree of MSI is a significant prognosticator for the OS of IMRT-treated NPCs, and the prognosis of patients with lateral MSI extension (LPM and ITF) were shown to be significantly worse than those affected only MPM or the T3-stage disease. Thus, it is highly recommended that lateral MSI extension be a higher T-staging category.

False-positive finding of retropharyngeal lymph node recurrence in both fluorine (18)FDG PET and MRI in a patient with nasopharyngeal carcinoma

BACKGROUND

Biopsy of the retropharyngeal node is not routinely accessible. The diagnosis of retropharyngeal lymph node recurrence in patients with nasopharyngeal carcinoma (NPC) is often based on an imaging study.

METHODS

We reported a patient with NPC who was incorrectly diagnosed with left retropharyngeal lymph node recurrence by both MRI and positron emission tomography (PET)/CT.

RESULTS

A woman who was treated for stage IVA NPC 2 years previously was found to have a nodal lesion in the left retropharyngeal space on MRI together with focal fluorodeoxyglucose (FDG) uptake on PET/CT. Locoregional recurrence was suspected, and surgery was performed. Subsequent pathology results showed reactive lymphoid hyperplasia.

CONCLUSION

Although tissue biopsy for the retropharyngeal node is technically difficult, this case demonstrates that tumor recurrence cannot be diagnosed even based on both positive findings on MRI and PET/CT in patients with NPC.

Pretreatment Diffusion-Weighted MRI Can Predict the Response to Neoadjuvant Chemotherapy in Patients with Nasopharyngeal Carcinoma

Purpose. To explore the potential of diffusion-weighted (DW) magnetic resonance imaging (MRI) using apparent diffusion coefficient (ADC) for predicting the response to neoadjuvant chemotherapy in nasopharyngeal carcinoma (NPC). Methods and Materials. Ninety-two consecutive patients with NPC who underwent three cycles of neoadjuvant chemotherapy were retrospectively analyzed. DW and anatomical MRI were performed before and after neoadjuvant chemotherapy prior to radiotherapy. Pretreatment ADCs and percentage increases in ADC after chemotherapy were calculated for the primary lesions and metastatic adenopathies. Receiver operating characteristic curve analysis was used to select optimal pretreatment ADCs. Results. Pretreatment mean ADCs were significantly lower for responders than for nonresponders (primary lesions, P = 0.012; metastatic adenopathies, P = 0.013). Mean percentage increases in ADC were higher for responders than for nonresponders (primary lesions, P = 0.008; metastatic adenopathies, P < 0.001). The optimal pretreatment primary lesion and metastatic adenopathy ADCs for differentiating responders from nonresponders were 0.897 × 10⁻³ mm²/sec and 1.031 × 10⁻³ mm²/sec, respectively. Conclusions. NPC patients with low pretreatment ADCs tend to respond better to neoadjuvant chemotherapy. Pretreatment ADCs could be used as a new pretreatment imaging biomarker of response to neoadjuvant chemotherapy.

Prognostic value of the primary lesion apparent diffusion coefficient (ADC) in nasopharyngeal carcinoma: a retrospective study of 541 cases

The prognostic value of the primary lesion pretreatment apparent diffusion coefficient (ADC), which is obtained by diffusion-weighted magnetic resonance imaging (MR-DWI), remains unknown in nasopharyngeal carcinoma (NPC). Thus, to investigate whether the pretreatment ADC value as measured from the primary site on MR-DWI is an independent prognostic factor in NPC, we retrospectively reviewed a cohort of 541 patients with histologically-proven stage I-IVB NPC. All patients underwent MRI using a 3-Tesla system (Trio Tim; Siemens, Erlangen Germany). To calculate ADC, the primary lesion was designated on the ADC map at the level of the largest tumor diameter to cover most of the lesion, avoiding cystic or necrotic components. Median and mean (±SD) pretreatment ADC were 0.713 and 0.716 ± 0.079 × 10⁻³ mm²/s, respectively. Univariate and multivariate analysis confirmed high pretreatment ADC was a good prognostic factor for poor local relapse-free survival and disease-free survival. Furthermore, the area under the ROC curve for prediction of local failure significantly increased when pretreatment ADC was combined with T classification (P = 0.004). Thus, pretreatment ADC might provide useful information for predicting outcome and selecting high-risk patients appropriate for more aggressive therapy. Further studies are warranted to investigate the biological basis of this observation.

Prognostic Value of (18)F-FDG PET-CT in Nasopharyngeal Carcinoma: Is Dynamic Scanning Helpful?

OBJECTIVES

To evaluate the differences in prognostic values of static and dynamic PET-CT in nasopharyngeal carcinoma (NPC).

MATERIAL AND METHODS

Forty-five patients who had static scan were recruited. Sixteen had dynamic scan. The primary lesions were delineated from standardized uptake value (SUV) maps from static scan and K i maps from dynamic scan. The average follow-up lasted for 34 months. The patients who died or those with recurrence/residual disease were considered "poor outcome"; otherwise they were considered "good outcome." Fisher's exact test and ROC analysis were used to evaluate the prognostic value of various factors.

RESULTS

Tumor volume thresholded by 40% of maximal SUV (VOLSUV40) significantly predicted treatment outcome (p = 0.024) in the whole cohort. In 16 patients with dynamic scan, all parameters by dynamic scan were insignificant in predicting the outcome. The combination of maximal SUV, maximal K i , VOLSUV40, and VOL K i 37 (the tumor volume thresholded by 37% maximal K i ) achieved the highest predicting accuracy for treatment outcome with sensitivity, specificity, and accuracy of 100% in these 16 patients; however this improvement compared to VOLSUV40 was insignificant.

CONCLUSION

Tumor volume from static scan is useful in NPC prognosis. However, the role of dynamic scanning was not justified in this small cohort.

The prognosis of nasopharyngeal carcinoma involving masticatory muscles: a retrospective analysis for revising T subclassifications

This work is a retrospective study of magnetic resonance imaging (MRI) and T-stage subclassifications of nasopharyngeal carcinoma (NPC) involving the masticatory muscles (MMs). We examined how involvement of MMs influences the clinical T-stage classifications and the survival outcomes of NPC patients. MRI data as well as the medical records from 816 NPC patients were analyzed retrospectively. All cases were restaged according to the seventh edition of American Joint Committee on Cancer staging system criteria. The overall survival (OS), local relapse-free survival (LRFS), and distant metastasis-free survival (DMFS) were analyzed by the Kaplan-Meier method, and their survival outcomes between different degrees of MM involvement and different T classifications were compared by using the log-rank test. All statistical analyses were conducted on SPSS 18.0 software. P > 0.05 was considered significant. Of the 816 NPC patients analyzed, 283 (34.68%) had tumors that involved MMs. All of those 283 patients involved the medial pterygoid muscle, and 125 cases (15.32%) involved the lateral pterygoid muscle. Multivariate analysis identified MM involvement as an independent prognostic factor for patient's OS (P = 0.007) and LRFS (P = 0.024). MM involvement significantly correlated with a lower OS and LRFS (P < 0.01). In addition, compared with concurrent involvement of the medial and lateral pterygoid muscle, the medial pterygoid muscle involvement correlated with a higher OS and LRFS (P < 0.05). Among NPC patients, T-classifications 1 to 4 usually predicted the ultimate OS, LRFS, and DMFS (P > 0.1), unless the cancer involved the lateral pterygoid muscle. NPC involving the lateral pterygoid muscle presents a worse survival outcome than that involving the medial pterygoid muscle. Any cancer involving the lateral pterygoid muscle should be classified in a higher T-stage subclassification.

Fate of patients with nasopharyngeal cancer who developed distant metastasis as first failure after definitive radiation therapy

BACKGROUND

No consensus has been reached on the optimal treatment for patients with nasopharyngeal cancer (NPC) who develop distant metastasis after initial radiation therapy (RT).

METHODS

Two hundred eighty-two patients with NPC received curative RT (+/- chemotherapy). Forty-six patients (16.3%) who developed distant metastasis as first failure formed the study group for the current analysis.

RESULTS

The median interval from initial RT until distant metastasis was 11.6 months. With a median follow-up of 30 months among survivors, overall survival (OS) rates at 2 and 5 years were 53.7% and 30.5%, respectively. On multivariate analyses, 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/CT for initial staging, RT plus chemotherapy as initial treatment, metastatic lesion number <6, disease-free interval >9 months, distant metastasis only to lungs, and treatment with curative intent after distant metastasis were predictive of significantly better OS.

CONCLUSION

Combined with FDG-PET/CT, an aggressive treatment approach using locoregional modalities might be beneficial to patients with NPC with favorable prognostic factors, even after distant metastasis. © 2015 Wiley Periodicals, Inc. Head Neck 38: E293-E299, 2016.

Nasopharyngeal carcinoma: comparison of diffusion and perfusion characteristics between different tumour stages using intravoxel incoherent motion MR imaging

OBJECTIVE

To explore intravoxel incoherent motion (IVIM) characteristics of nasopharyngeal carcinoma (NPC) and relationships with different tumour stages.

METHODS

We prospectively recruited 80 patients with newly diagnosed undifferentiated NPC. Diffusion-weighted MR imaging was performed and IVIM parameters (D, pure diffusion; f, perfusion fraction; D*, pseudodiffusion coefficient) were calculated. Patients were stratified into low and high tumour stage groups based on American Joint Committee on Cancer (AJCC) and TNM staging for determination of the predictive powers of IVIM parameters using t test, multiple logistic regression and ROC curve analyses.

RESULTS

D, f and D* were all statistically significantly lower in high-stage groups in AJCC, T and N staging. D, f and D* were all independent predictors of AJCC staging, f and D* were independent predictors of T staging, and D was an independent predictor of N staging. D was most powerful for AJCC and N staging, whereas f was most powerful for T staging. Optimal cut-off values (area under the curve, sensitivity, specificity, positive likelihood ratio, negative likelihood ratio) were as follows: AJCC stage, D = 0.782 × 10(-3) mm(2)/s (0.915, 93.3 %, 76.2 %, 3.92, 0.09); T staging, f = 0.133 (0.905, 80.5 %, 92.5 %, 10.73, 0.21); N staging, D = 0.761 × 10(-3) mm(2)/s (0.848, 87.5 %, 66.7 %, 2.62, 0.19). Multivariate analysis showed no diagnostic improvement.

CONCLUSION

Nasopharyngeal carcinoma has distinctive intravoxel incoherent motion characteristics parameters in different tumour staging, potentially helping pretreatment staging.

KEY POINTS

• Magnetic resonance imaging is increasingly used to assess nasopharyngeal carcinoma (NPC). • NPC has distinctive diffusion/perfusion characteristics at different stages. • Non-invasive MR imaging may help pretreatment staging prediction. • Diffusion properties of NPC best correlate with AJCC and N staging. • Perfusion properties of NPC best correlate with T staging.