[18F]fluorodeoxyglucose positron emission tomography is more sensitive than skeletal scintigraphy for detecting bone metastasis in endemic nasopharyngeal carcinoma at initial staging

Intravertebral collateral enhancement resembling sclerotic metastatic disease in a case of cervical epidural abscess

Vertebral body enhancement is occasionally seen on postcontrast CT imaging in the absence of osseous pathology. This enhancement can mimic sclerotic osseous metastatic disease, leading to a diagnostic dilemma for radiologists and increasing the chance of misinterpretation. Existing literature has focused on the association between this enhancement and concomitant central venous system obstruction. We report a 61-year-old woman with a history of nasopharyngeal carcinoma presenting with an epidural abscess who exhibited vertebral body enhancement resembling sclerotic metastatic disease without imaging evidence of central venous obstruction or vertebral osseous metastatic disease. Awareness of this unique presentation may prevent the incorrect diagnostic errors and their associated negative effects on patients.

Prognostic value of pre-treatment 18F-FDG PET uptake for nasopharyngeal carcinoma

PURPOSE

To evaluate the prognostic value of maximal standardized uptake values (SUVmax) from serial fluor-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in patients with nasopharyngeal carcinoma (NPC).

MATERIALS AND METHODS

Fifty-two patients with NPC who underwent 18F-FDG PET/CT scan before radiotherapy with/without chemotherapy were reviewed retrospectively. Twenty-seven patients (52%) were applied 3-D conformal radiotherapy and 25 patients (48%) applied intensity-modulated radiotherapy (IMRT). Fourteen (27%) patients were given neoadjuvant chemotherapy and forty-four (84.6%) patients were given concomitant and adjuvant chemotherapy.

RESULTS

Median follow-up time was 34 months (range 5.6-66.4 months). Forty-four (84.6%) patients were alive at last follow-up and eight (15.4%) had died. The best cut-off value of the SUVmax for the primary tumor site (SUVmax-PT) was 13 and 9 for the lymph nodes (SUVmax-LN). Patients with SUVmax-PT ≥ 13.0 and SUVmax-LN ≥ 9 had a significantly higher risk for the development of the distant metastases (p = 0.044 and p = 0.038). DFS was affected in patients with SUVmax-PT ≥ 13 (log rank χ 2 = 2.54, p = 0.017) and was significantly lower in patients with SUVmax-LN ≥ 9 for the lymph nodes (log rank χ 2 = 5.81, p = 0.013). OS was not affected by SUV levels. A multivariate Cox proportional hazard model of DFS included age (≥ 40), SUVmax-LN (< 9), T stage (T1-2) and neoadjuvant chemotherapy are significantly better prognosis for the DFS.

CONCLUSION

18F-FDG PET/CT uptake before treatment, as determined by SUVmax, may be a valuable tool to evaluate prognosis in NPC patients.

Comparison of [18F]FDG and [68 Ga]pentixafor PET/CT in Nasopharyngeal Carcinoma

PURPOSE

This study aimed to explore the feasibility of [68 Ga]pentixafor positron emission tomography/computed tomography (PET/CT) in patients with nasopharyngeal carcinoma (NPC).

PROCEDURES

This prospective study included patients with NPC who underwent [68 Ga]pentixafor PET/CT and 2-[18F]fuoro-2-deoxy-D-glucose ([18F]FDG) PET/CT within one week between November 2022 and March 2023. The [68 Ga]pentixafor and [18F]FDG uptakes in primary and metastatic lesions were measured and compared.

RESULTS

Twenty-five participants (21 patients for initial stage and four patients for recurrence detection) were enrolled in our study. The participants underwent [18F]FDG PET/CT and [68 Ga]pentixafor PET/CT. [68 Ga]pentixafor PET/CT had the same detection rate as [18F]FDG for primary tumor (96% vs. 96%). The [68 Ga]pentixafor maximum standard uptake value (SUVmax) and target-to-background ratio (TBR) of primary tumors were lower than those of [18F]FDG (SUVmax: 8.13 ± 2.78 vs. 14.25 ± 6.45; P < 0.01; TBR: 5.17 ± 2.14 vs. 9.81 ± 5.30, P < 0.01). The difference between tumor volume of [68 Ga]pentixafor (TVpentixafor) and tumor volume of [18F]FDG (TVFDG) showed no significance (median: 16.01 vs. 9.56, P = 0.332). In the detection of suspected metastatic cervical lymph nodes (CLNs), [68 Ga]pentixafor PET possessed a lower SUVmax than [18F]FDG PET/CT (SUVmax: 6.86 ± 2.63 vs. 10.39 ± 5.28, P < 0.01), but there was no significant difference in the detection rate between [68 Ga]pentixafor and [18F]FDG PET/CT (96 vs. 98, P = 0.613).

CONCLUSIONS

[68 Ga]pentixafor is a promising imaging tracer for detecting primary and metastatic NPC. [68 Ga]pentixafor PET/CT is comparable to [18F]FDG PET/CT in the detection rate of primary tumors and metastatic cervical lymph nodes in nasopharyngeal carcinoma, but [68 Ga]pentixafor uptake was heterogeneous. [68 Ga]pentixafor PET/CT may help select patients most likely to benefit from CXCR4-directed endoradiotherapy.

CLINICAL TRIAL REGISTRATION NO

ChiCTR2200065902.

Head and neck MRI-based T stage and [18F]FDG PET/CT-based N/M stage improved prognostic stratification in primary nasopharyngeal carcinoma

OBJECTIVES

To evaluate whether MRI-based T stage (TMRI), [18F]FDG PET/CT-based N (NPET/CT), and M stage (MPET/CT) are superior in NPC patients' prognostic stratification based on long-term survival evidences, and whether TNM staging method involving TMRI + NPET/CT + MPET/CT could improve NPC patients' prognostic stratification.

METHODS

From April 2007 to December 2013, 1013 consecutive untreated NPC patients with complete imaging data were enrolled. All patients' initial stages were repeated based on (1) the NCCN guideline recommended "TMRI + NMRI + MPET/CT" ("MMP") staging method; (2) the traditional "TMRI + NMRI + Mconventional work-up (CWU)" ("MMC") staging method; (3) the single-step "TPET/CT + NPET/CT + MPET/CT" ("PPP") staging method; or (4) the "TMRI + NPET/CT + MPET/CT" ("MPP") staging method recommended in present research. Survival curve, ROC curve, and net reclassification improvement (NRI) analysis were used to evaluate the prognosis predicting ability of different staging methods.

RESULTS

[18F]FDG PET/CT performed worse on T stage (NRI =  - 0.174, p < 0.001) but better on N (NRI = 0.135, p = 0.004) and M stage (NRI = 0.126, p = 0.001). The patients whose N stage upgraded by [18F]FDG PET/CT had worse survival (p = 0.011). The "TMRI + NPET/CT + MPET/CT" ("MPP") method performed better on survival prediction when compared with "MMP" (NRI = 0.079, p = 0.007), "MMC" (NRI = 0.190, p < 0.001), or "PPP" method (NRI = 0.107, p < 0.001). The "TMRI + NPET/CT + MPET/CT" ("MPP") method could reclassify patients' TNM stage to a more appropriate stage. The improvement is significant in patients with more than 2.5-years follow-up according to the time-dependent NRI values.

CONCLUSIONS

The MRI is superior to [18F]FDG PET/CT in T stage, and [18F]FDG PET/CT is superior to CWU in N/M stage. The "TMRI + NPET/CT + MPET/CT" ("MPP") staging method could significantly improve NPC patients' long-term prognostic stratification.

CLINICAL RELEVANCE STATEMENT

The present research provided long-term follow-up evidence for benefits of MRI and [18F]FDG PET/CT in TNM staging for nasopharyngeal carcinoma, and proposes a new imaging procedure for TNM staging incorporating MRI-based T stage and [18F]FDG PET/CT-based N and M stage, which significantly improves long-term prognostic stratification for patients with NPC.

KEY POINTS

• The long-term follow-up evidence of a large-scale cohort was provided to evaluate the advantages of MRI, [18F]FDG PET/CT, and CWU in the TNM staging of nasopharyngeal carcinoma. • A new imaging procedure for TNM stage of nasopharyngeal carcinoma was proposed.

Assessment of bone lesions with 18 F-FDG PET/MRI in patients with nasopharyngeal carcinoma

PURPOSE

The purpose of this study is to evaluate the role of 18 fluorodeoxyglucose ( 18 F) PET/MRI ( 18 F-FDG PET/MRI) for detecting bone metastasis in nasopharyngeal carcinoma (NPC).

PATIENTS AND METHODS

Between May 2017 and May 2021, 58 histologically proven NPC patients who underwent both 18 F-FDG PET/MRI and 99m Tc-MDP planar bone scintigraphy (PBS) for tumor staging were included. With the exception of the head, the skeletal system was classified into four groups: the spine, the pelvis, the thorax and the appendix.

RESULTS

Nine (15.5 %) of 58 patients were confirmed to have bone metastasis. There was no statistical difference between PET/MRI and PBS in patient-based analysis ( P  = 0.125). One patient with a super scan was confirmed to have extensive and diffuse bone metastases and excluded for lesion-based analysis. Of the 57 patients, all 48 true metastatic lesions were positive in PET/MRI whereas only 24 true metastatic lesions were positive in PBS (spine: 8, thorax: 0, pelvis: 11 and appendix: 5). PET/MRI was observed to be more sensitive than PBS in lesion-based analysis (sensitivity 100.0% versus 50.0 %; P  < 0.001).

CONCLUSIONS

Compared with PBS for tumor staging of NPC, PET/MRI was observed to be more sensitive in the lesion-based analysis of bone metastasis.

Do all patients at the initial stage of nasopharyngeal carcinoma need bone metastasis screening? A retrospective study

BACKGROUND

To identify patients at low risk of synchronous bone metastasis who should not receive bone scans when initially diagnosed with nasopharyngeal carcinoma (NPC).

METHODS

In total, 6652 patients were enrolled in the training cohort and 1919 patients in the multicenter external validation cohort. Logistic regression analyses were performed to assess independent predictors of synchronous bone metastasis for the nomogram model.

RESULTS

After risk stratification, 46.3% (3081/6652) patients were separated into the low-risk group with an incidence of 0.71% for synchronous bone metastasis. The odds ratio of the intermediate and high-risk groups was 5.61 and 23.82 times that of the low-risk group, respectively. For patients with high EBV DNA, we recommend routine screening for N2-3 female patients, but that all male subgroups are screened.

CONCLUSIONS

Bone scans should not be routine. Patients in the low-risk group should not be screened, which would avoid excessive radiation and economize iatrical resource.

Skeletal scintigraphy as an important complement for detecting bone metastasis from nasopharyngeal carcinoma

Bone metastasis occurs frequently in patients with nasopharyngeal carcinoma (NPC). Although fluorine-18 fluorodeoxyglucose positron emission tomography with computed tomography (PET/CT) has been proven to be more sensitive at detecting bone metastases than Technetium-99m methylene diphosphonate skeletal scintigraphy in pretreatment patients with NPC in most clinical settings, there have been metastatic lesions that were positive on skeletal scintigraphy but negative on PET/CT scans. Herein, we report the case of a patient with stage IV NPC that manifested as multiple metabolically abnormal lesions on pretreatment skeletal scintigraphy and were considered malignant although they were negative on PET/CT examination. Follow-up evaluations with both skeletal scintigraphy and PET/CT scans as post-therapeutic imaging are also presented.

Predicting Bone Metastasis Risk Based on Skull Base Invasion in Locally Advanced Nasopharyngeal Carcinoma

Objective

To develop and validate a bone metastasis prediction model based on skull base invasion (SBI) in patients with locally advanced nasopharyngeal carcinoma (LA-NPC).

Methods

This retrospective cohort study enrolled 290 patients with LA-NPC who received intensity-modulated radiation therapy in two hospitals from 2010 to 2020. Patient characteristics were grouped by SBI and hospital. Both unadjusted and multivariate-adjusted models were used to determine bone metastasis risk based on SBI status. Subgroup analysis was performed to investigate heterogeneity using a forest graph. Cox proportional hazard regression analysis was used to screen for risk factors of bone metastasis-free survival (BMFS). A nomogram of BMFS based on SBI was developed and validated using C-index, receiver operating characteristic curve, calibration curves, and decision curve analysis after Cox proportional hazard regression analysis.

Results

The incidence of bone metastasis was 14.83% (43/290), 20.69% (24/116), and 10.92% (19/174) in the overall population, SBI-positive group, and SBI-negative group, respectively. In the unadjusted model, SBI was associated with reduced BMFS [HR 2.43 (1.32–4.47), P = 0.004], and the results remained stable after three continuous adjustments (P <0.05). No significant interaction was found in the subgroup analyses (P for interaction >0.05). According to Cox proportional hazard regression analysis and clinical value results, potential risk factors included SBI, Karnofsky performance status, TNM stage, induction chemotherapy, concurrent chemoradiotherapy, and adjuvant chemotherapy. Using a training C-index of 0.80 and a validation C-index of 0.79, the nomogram predicted BMFS and demonstrated satisfactory prognostic capability in 2, 3, and 5 years (area under curve: 83.7% vs. 79.6%, 81.7% vs. 88.2%, and 79.0% vs. 93.8%, respectively).

Conclusion

Skull base invasion is a risk factor for bone metastasis in patients with LA-NPC. The SBI-based nomogram model can be used to predict bone metastasis and may assist in identifying LA-NPC patients at the highest risk of bone metastasis.

Radical resection for solitary thoracic spinous-process metastasis: a case report and technical note

INTRODUCTION

Bone metastases confined to the posterior elements of the spine are rarely treated, as there exist no established radical surgical treatment options for this area. Herein, we present a case report of and technical note on a patient who underwent radical resection for a metastatic tumor in the thoracic spinous process.

CASE PRESENTATION

A 34-year-old male presented with a nasopharyngeal carcinoma with a solitary metastatic focus in the spinous process of the 10th thoracic vertebra. Imaging revealed that the tumor was confined to the spinous process and the surrounding soft tissues. No tumor was noted in the pedicles, vertebral body, and cortical bone on the ventral side of the lamina, as well as within the spinal canal. As treatment for this solitary metastatic lesion, we decided to perform radical resection with sufficient margins that would include the involved spinous process and all surrounding soft tissues exhibiting evidence of tumor infiltration. The posterior elements of the 9th-11th vertebrae, multifidus muscles, and skin were widely resected en bloc using a T-saw. The posterior elements of the spinal column were resected at the level of pedicles without full visualization of the involved dural sac. The tumor-infiltrated soft tissues surrounding the T10 vertebral spinous process were excised without full visualization of the tumor. Adjuvant therapy was not administered postoperatively. During the second year of follow-up, no signs of recurrence or metastasis were noted.

DISCUSSION

Our proposed technique allows wide resection of a solitary focus of metastasis in the posterior elements of the spine.

Selectively recommend 18F-FDG PET/CT for patients with de novo nasopharyngeal carcinoma in endemic areas

INTRODUCTION

To identify the subset of patients with de novo nasopharyngeal carcinoma (NPC) for whom [¹⁸F] fluorodeoxyglucose positron emission tomography and computed tomography (¹⁸F-FDG PET/CT) should be recommended, and to determine whether PET/CT is a cost-effective decision for precise M staging in endemic areas.

MATERIALS AND METHODS

Retrospective analysis of data of 4469 patients diagnosed with de novo NPC between January 2014 and December 2019. The detection rate of distant metastasis was compared between different groups. Univariate and multiple logistic regression analysis was applied to identify the risk factors for distant metastasis. The cost-effectiveness of the diagnostic strategies was assessed.

RESULTS

The detection rate of distant metastasis in the whole cohort was 5.46%. In multivariate analysis, male sex, T3-4 stage, N2-3 stage, and high plasma Epstein-Barr virus (EBV) DNA (≥ 14,650 copies/mL) were risk factors for distant metastases. NPC patients with T3-4 stage combined with N2-3 stage, high EBV DNA combined with male sex, or N2-3 stage combined with high EBV DNA were defined as recommended group with relatively higher tendency for metastasis. Distant metastasis incidence in recommended group and unrecommended group were 10.25% and 1.75%, respectively (P < 0.001). In the recommended group, PET/CT significantly improved the detection rate of distant metastasis (13.25% vs 9.02%, P = 0.005). Cost-effectiveness analysis revealed that additional cost for every one percent increase in distant metastasis detection rate was $22,785.58 in the recommended group (< Willingness-to-pay (WTP) threshold of $32,700.00) and $310,912.90 in the unrecommended group.

CONCLUSIONS

In patients with de novo NPC, the tendency for metastasis can be predicted based on clinical parameters. ¹⁸F-FDG PET/CT should be selectively recommended for the subset of patients with a relatively higher tendency for metastasis.

Comparison of PET/CT and MRI in the Diagnosis of Bone Metastasis in Prostate Cancer Patients: A Network Analysis of Diagnostic Studies

BACKGROUND

Accurate diagnosis of bone metastasis status of prostate cancer (PCa) is becoming increasingly more important in guiding local and systemic treatment. Positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) have increasingly been utilized globally to assess the bone metastases in PCa. Our meta-analysis was a high-volume series in which the utility of PET/CT with different radioligands was compared to MRI with different parameters in this setting.

MATERIALS AND METHODS

Three databases, including Medline, Embase, and Cochrane Library, were searched to retrieve original trials from their inception to August 31, 2019 according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. The methodological quality of the included studies was assessed by two independent investigators utilizing Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). A Bayesian network meta-analysis was performed using an arm-based model. Absolute sensitivity and specificity, relative sensitivity and specificity, diagnostic odds ratio (DOR), and superiority index, and their associated 95% confidence intervals (CI) were used to assess the diagnostic value.

RESULTS

Forty-five studies with 2,843 patients and 4,263 lesions were identified. Network meta-analysis reveals that 68Ga-labeled prostate membrane antigen (68Ga-PSMA) PET/CT has the highest superiority index (7.30) with the sensitivity of 0.91 and specificity of 0.99, followed by 18F-NaF, 11C-choline, 18F-choline, 18F-fludeoxyglucose (FDG), and 18F-fluciclovine PET/CT. The use of high magnetic field strength, multisequence, diffusion-weighted imaging (DWI), and more imaging planes will increase the diagnostic value of MRI for the detection of bone metastasis in prostate cancer patients. Where available, 3.0-T high-quality MRI approaches 68Ga-PSMA PET/CT was performed in the detection of bone metastasis on patient-based level (sensitivity, 0.94 vs. 0.91; specificity, 0.94 vs. 0.96; superiority index, 4.43 vs. 4.56).

CONCLUSIONS

68Ga-PSMA PET/CT is recommended for the diagnosis of bone metastasis in prostate cancer patients. Where available, 3.0-T high-quality MRI approaches 68Ga-PSMA PET/CT should be performed in the detection of bone metastasis.

Nasopharyngeal carcinoma in children and adolescents: The EXPeRT/PARTNER diagnostic and therapeutic recommendations

Nasopharyngeal carcinoma (NPC) is a rare pediatric tumor. Collaborative studies performed over the last decades showed improved results compared to historical data, but standardized guidelines for diagnosis and management of pediatric NPC are still unavailable. This study presents a European consensus guideline for the diagnosis and treatment of pediatric NPC developed by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT). Main recommendations include induction chemotherapy with cisplatin and 5-flurouracil, concomitant chemoradiotherapy in advanced disease, and to consider maintenance treatment with interferon beta (IFN-β) for selected high-risk patients. Dose adjustments of radiotherapy based on response to induction chemotherapy may decrease the rates of long-term treatment-related complications that affect most of the survivors.

Low value of whole-body dual-modality [18f]fluorodeoxyglucose positron emission tomography/computed tomography in primary staging of stage I-II nasopharyngeal carcinoma: a nest case-control study

Objectives

The value of using PET/CT for staging of stage I–II NPC remains unclear. Hence, we aimed to investigate the survival benefit of PET/CT for staging of early-stage NPC before radical therapy.

Methods

A total of 1003 patients with pathologically confirmed NPC of stages I–II were consecutively enrolled. Among them, 218 patients underwent both PET/CT and conventional workup ([CWU], head-and-neck MRI, chest radiograph, liver ultrasound, bone scintigraphy) before treatment. The remaining 785 patients only underwent CWU. The standard of truth (SOT) for lymph node metastasis was defined by the change of size according to follow-up MRI. The diagnostic efficacies were compared in 218 patients who underwent both PET/CT and CWU. After covariate adjustment using propensity scoring, a cohort of 872 patients (218 with and 654 without pre-treatment PET/CT) was included. The primary outcome was overall survival based on intention to treat.

Results

Retropharyngeal lymph nodes were metastatic based on follow-up MRI in 79 cases. PET/CT was significantly less sensitive than MRI in detecting retropharyngeal lymph node lesions (72.2% [62.3–82.1] vs. 91.1% [84.8–97.4], p = 0.004). Neck lymph nodes were metastatic in 89 cases and PET/CT was more sensitive than MRI (96.6% [92.8–100.0] vs. 76.4% [67.6–85.2], p < 0.001). In the survival analyses, there was no association between pre-treatment PET/CT use and improved overall survival, progression-free survival, local relapse-free survival, regional relapse-free survival, and distant metastasis-free survival.

Conclusions

This study showed PET/CT is of little value for staging of stage I–II NPC patients at initial imaging.

Key Points

• PET/CT was more sensitive than MRI in detecting neck lymph node lesions whereas it was significantly less sensitive than MRI in detecting retropharyngeal lymph node lesions.

• No association existed between pre-treatment PET/CT use and improved survival in stage I–II NPC patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-020-07478-1.

Nomogram for the prediction of primary distant metastasis of nasopharyngeal carcinoma to guide individualized application of FDG PET/CT

PURPOSE

This study aimed to establish an effective nomogram to predict primary distant metastasis (DM) in patients with nasopharyngeal carcinoma (NPC) to guide the application of PET/CT.

METHODS

In total, 3591 patients with pathologically confirmed NPC were consecutively enrolled. The nomogram was constructed based on 1922 patients treated between 2007 and 2014. Multivariate logistical regression was applied to identify the independent risk factors of DM. The predictive value of the nomogram was evaluated using the concordance index (C-index), calibration curve, probability density functions (PDFs), and clinical utility curve (CUC). The results were validated in 1669 patients enrolled from 2015 to 2016. Net reclassification improvement (NRI) was applied to compare performances of the nomogram with other clinical factors. The best cut-off value of the nomogram chosen for clinical application was analyzed.

RESULTS

A total of 355 patients showed primary DM among 3591 patients, yielding an incidence rate of 9.9%. Sex, N stage, EBV DNA level, lactate dehydrogenase level, and hemoglobin level were independent predictive factors for primary DM. C-indices in the training and validation cohort were 0.796 (95% CI, 0.76-0.83) and 0.779 (95% CI, 0.74-0.81), respectively. The NRI indices demonstrated that this model had better predictive performance than plasma EBV DNA level and N stage. We advocate for a threshold probability of 3.5% for guiding the application of PET/CT depending on the clinical utility analyses.

CONCLUSION

This nomogram is a useful tool to predict primary DM of NPC and guide the clinical application of PET/CT individually at the initial staging.

Observer agreement and accuracy of 18F-sodium fluoride PET/computed tomography in the diagnosis of skull-base bone invasion and osseous metastases in newly diagnosed nasopharyngeal carcinoma

OBJECTIVES

To evaluate the interobserver agreement and the diagnostic performance in F-sodium fluoride (F-NaF) PET/computed tomography (CT) for the detection of skull-base bone invasion (SBBI) and osseous metastases in patients with newly diagnosed nasopharyngeal carcinoma (NPC).

METHODS

One hundred seventeen patients with newly diagnosed NPC between 2017 and 2019 who underwent F-NaF PET/CT was in included. Two experienced observers independently evaluated the F-NaF PET/CT of SBBI and osseous metastases on a patient level using a two-category scale present on a dichotomous scale, respectively. On a patient level, the diagnostic performance was calculated using a sensitivity analysis.

RESULTS

The interobserver agreement on a patient level of SBBI and osseous metastases were perfect on a patient-level (κ: 0.85), (κ: 0.808), respectively. On a lesion level of detection of osseous metastases, the observers agreed on the number as well as the location of osseous metastases in 101 (86.3%) patients. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of detection of SBBI and osseous metastases were ranged 0.911-0.962, 0.921-0.974, 0.932-0.957, 0.962-0.986, and 0.841-0.923, and ranged 0.917-0.958, 0.899-0.957, 0.906-0.949, 0.863-0.936, and 0.939-0.970, respectively.

CONCLUSION

The interobserver agreement of F-NaF PET/CT for the detection of SBBI and osseous metastases in patients with NPC were both very high among trained observers. Moreover, the diagnostic performance of NaF PET/CT was satisfactory, rendering NaF PET/CT a robust tool in the diagnostic armamentarium.

Surgical Treatment Outcomes of Spinal Metastases of Nasopharyngeal Carcinoma: The First Report of 30 Patients from a Single Center

Background

Studies focused on surgical interventions of spinal metastases of nasopharyngeal carcinoma (SMNPC) are blank.

Methods

Patients with SMNPC who received surgical treatment in our center between 2005 and 2017 were included. Univariate and multivariate analysis of various clinical characteristics and operation-related data were analyzed to identify the independent factors that affected prognosis. Factors with P values of 0.1 or less were subjected to multivariate Cox regression analysis. P values of 0.05 or less were considered statistically significant.

Results

A total of 30 patients with SMNPC treated with surgery were included. The thoracic spine was the most frequently involved site. The patients in this series achieved good overall survival (OS, 20.26 months) with limited perioperative complications. The univariate analysis suggested that preoperative Karnofsky performance scale, number of spinal metastases, number of visceral metastases, preoperative Frankel score, surgical resection mode and Ki 67 were potential prognostic factors. In the multivariate analyses, number of visceral metastases, preoperative Frankel score and resection mode were found to be independent prognostic factors.

Conclusion

This is the first study focusing on surgical outcomes in SMNPC. The thoracic spine was the most frequently involved site of SMNPC. Preoperative Frankel score, number of visceral metastasis and surgical resection mode were independent prognostic factors for SMNPC. Combined with adjuvant therapies, surgical interventions should be recommended early when necessary.

Bone Metastases Pattern in Newly Diagnosed Metastatic Nasopharyngeal Carcinoma: A Real-World Analysis in the SEER Database

Objective

To evaluate the prevalence rate and survival situation of bone metastases in initial nasopharyngeal carcinoma (NPC) patients and the hazard and forecast elements of bone metastases NPC patients. Patients and Methods. The data collected from Surveillance, Epidemiology, and End Results (SEER) program between 2010 and 2016 were evaluated. Univariate and multivariable logistic analysis and the Cox regression were carried out to estimate predictors and elements of the being of bone metastases at diagnosis, respectively. The overall survival of different subgroups were appraised by log-rank tests and the Kaplan–Meier analysis.

Results

Factors including male sex, higher N stage, presence of liver, and brain or lung metastases were largely related to the occurrence of bone metastases. The median survival time for bone metastasis NPC patients was 14.0 months. A factor of more than one primary sequence number predicted worse survival.

Conclusion

The data offer corresponding risks and prognostic indicators of bone metastases for NPC patients.

Comparison of 18F-FDG PET/MRI, MRI, and 18F-FDG PET/CT for the detection of synchronous cancers and distant metastases in patients with oropharyngeal and hypopharyngeal squamous cell carcinoma

PURPOSE

In this prospective study, we sought to compare the clinical utility of fluorodeoxyglucose PET/MRI, MRI, and PET/CT in the detection of synchronous cancers and distant metastases in patients with oropharyngeal and hypopharyngeal squamous cell carcinoma (OHSCC).

METHODS

We examined 198 consecutive patients with biopsy-proven OHSCC who agreed to receive chemoradiation. All patients underwent pretreatment PET/MRI and PET/CT on the same day. Patients were followed-up for a minimum of 12 months or until death. The McNemar's test and receiver-operating characteristic (ROC) curves were used to compare sensitivity/specificity and the diagnostic capabilities of PET/MRI, MRI, and PET/CT, respectively.

RESULTS

We identified 55 patients (27.7%) who had synchronous cancers and/or distant metastases (number of involved sites: 83). The results of site-based analysis revealed that the sensitivity of PET/MRI was 15.7% higher than that of MRI (73.5% versus 57.8%, p < 0.001) and 3.6% higher compared with PET/CT (73.5% versus 69.9%, p = 0.083), whereas the sensitivity of PET/CT was 12.1% higher than that of MRI (69.9% versus 57.8%, p = 0.012). On a patient-basis, ROC curve analysis demonstrated that PET/MRI yielded a greater area under curve than MRI (0.930 versus 0.905, p = 0.023). There were no significant differences in terms of diagnostic capability between MRI and PET/CT (0.905 versus 0.917, p = 0.469) and between PET/MRI and PET/CT (0.930 versus 0.917, p = 0.062).

CONCLUSIONS

In our cohort, PET/MRI showed a significantly higher diagnostic capability than MRI and no significant difference compared with PET/CT for the detection of synchronous cancers or distant metastases in patients with OHSCC.

Semiquantitative assessment of osteoblastic, osteolytic, and mixed lytic-sclerotic bone lesions on fluorodeoxyglucose positron emission tomography/computed tomography and bone scintigraphy

Bone scintigraphy is widely used to detect bone metastases, particularly osteoblastic ones, and F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) scan is useful in detecting lytic bone metastases. In routine studies, images are assessed visually. In this retrospective study, we aimed to assess the osteoblastic, osteolytic, and mixed lytic-sclerotic bone lesions semiquantitatively by measuring maximum standardized uptake value (SUV_max) on FDG PET/computed tomography (CT), maximum lesion to normal bone count ratio (ROImax) on bone scintigraphy, and Hounsfield unit (HU) on CT. Bone scintigraphy and FDG PET/CT images of 33 patients with various solid tumors were evaluated. Osteoblastic, osteolytic, and mixed lesions were identified on CT and SUV_max, ROI_max, and HU values of these lesions were measured. Statistical analysis was performed to determine if there is a difference in SUV_max, ROI_max, and HU values of osteoblastic, osteolytic, and mixed lesions and any correlation between these values. Patients had various solid tumors, mainly lung, breast, and prostate cancers. There were 145 bone lesions (22.8% osteoblastic, 53.1% osteolytic, and 24.1% mixed) on CT. Osteoblastic lesions had a significantly higher value of CT HU as compared to osteolytic and mixed lesions (P < 0.01). There was no significant difference in mean ROI_max and mean SUV_max values of osteolytic and osteoblastic bone lesions. There was no correlation between SUV_max and ROI_max, SUV_max and HU, and ROI_max and HU values in osteolytic, osteoblastic, and mixed lesions (P > 0.05). Not finding a significant difference in SUV_max and ROI_max values of osteoblastic, osteolytic, and mixed lesions and also lack of correlation between SUV_max, ROI_max, and HU values could be due to treatment status of the bone lesions, size of the lesion, nonmetastatic lesions, erroneous measurement of SUV_max and ROI_max, or varying metabolism in bone metastases originating from various malignancies.

Development and external validation of nomograms to predict the risk of skeletal metastasis at the time of diagnosis and skeletal metastasis-free survival in nasopharyngeal carcinoma

Background

The skeletal system is the most common site of distant metastasis in nasopharyngeal carcinoma (NPC); various prognostic factors have been reported for skeletal metastasis, though most studies have focused on a single factor. We aimed to establish nomograms to effectively predict skeletal metastasis at initial diagnosis (SMAD) and skeletal metastasis-free survival (SMFS) in NPC.

Methods

A total of 2685 patients with NPC who received bone scintigraphy (BS) and/or 18F–deoxyglucose positron emission tomography/computed tomography (18F–FDG PET/CT) and 2496 patients without skeletal metastasis were retrospectively assessed to develop individual nomograms for SMAD and SMFS. The models were validated externally using separate cohorts of 1329 and 1231 patients treated at two other institutions.

Results

Five independent prognostic factors were included in each nomogram. The SMAD nomogram had a significantly higher c-index than the TNM staging system (training cohort, P = 0.005; validation cohort, P < 0.001). The SMFS nomogram had significantly higher c-index values in the training and validation sets than the TNM staging system (P < 0.001 and P = 0.005, respectively). Three proposed risk stratification groups were created using the nomograms, and enabled significant discrimination of SMFS for each risk group.

Conclusion

The prognostic nomograms established in this study enable accurate stratification of distinct risk groups for skeletal metastasis, which may improve counseling and facilitate individualized management of patients with NPC.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3630-9) contains supplementary material, which is available to authorized users.

Comparison of 18FDG PET/PET-CT and bone scintigraphy for detecting bone metastases in patients with nasopharyngeal cancer: a meta-analysis

OBJECTIVE

We performed a meta-analysis to compare the diagnostic efficacy of ¹⁸FDG PET/PET-CT and bone scintigraphy (BS) for diagnosing bone metastatic cancers in nasopharyngeal cancer patients.

RESULTS

6 studies (1238 patients) fulfilled the inclusion criteria. The pooled sensitivities for ¹⁸FDG PET/PET-CT and BS were 0.81 (95% confidence interval [CI] = 0.70 to 0.98) and 0.39 (95% CI = 0.26 to 0.54), specificities were 0.99 (95% CI = 0.98 to 0.99) and 0.98 (95% CI = 0.96 to 0.99), and the areas under curve were 0.98 (95% CI = 0.97 to 0.99) and 0.84 (95% CI = 0.81 to 0.87).

MATERIALS AND METHODS

Several databases were searched for all available articles. We calculated the sensitivities, specificities, diagnostic odds ratios, likelihood ratios, and area under summary receiver operating characteristic curves for ¹⁸FDG PET/PET-CT and BS, respectively.

CONCLUSIONS

¹⁸FDG PET/PET-CT is superior to BS for diagnosing bone metastases in nasopharyngeal cancer patients.¹⁸FDG PET/PET-CT may enhance the diagnosis of bone metastases and provide more accurate information for the optimal management of nasopharyngeal cancer.

18F-Fluorodeoxyglucose-positron Emission Tomography/Computed Tomography Imaging of Metastatic Nasopharyngeal Cancer with Emphasis on the Distribution of Bone Metastases

Distant metastases change the prognosis of patients with nasopharyngeal carcinoma (NPC) which most commonly metastasizes to the bone. ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) is reported as useful in imaging NPC metastases. Our study assesses the incidence and distribution of bone metastases detected by ¹⁸F-FDG PET/CT in NPC. 717 ¹⁸F-FDG PET/CT scan reports of histologically proven NPC patients imaged in Singapore General Hospital, Singapore, between 2003 and 2009 were reviewed for the total number of metastases (scanned from vertex to mid-thigh) and analyzed for distribution. Of the 709 FDG avid metastases in these reports, 357/709 (50.35%) were locoregional nodal metastasis and 352/709 (49.65%) were distant metastases of which 192/709 (27.08%) of total metastases and 54.54% of distant metastases (192/352) were in the bones. The majority of the bone lesions 125/192 (65.1%) were in the axial skeleton with 109/192 (56.77%) in the lower skeleton (thoracolumbar spine, sacrum, and pelvis). The incidence of bone metastases in our study (27.08%) was higher than that reported in other studies, for example, 15% by Liu et al. and 11% (230 patients) by Caglar et al. Bone metastases have been reported in the femurs and the feet and as such some metastases may have been outside the field of view of the scans. In our study, 27% of FDG avid NPC metastases are in the bones.

Optimal Modality for Detecting Distant Metastasis in Primary Nasopharyngeal Carcinoma during Initial Staging: A Systemic Review and Meta-analysis of 1774 Patients

Purpose: To compare the diagnostic performance of two modalities commonly used for detecting distant metastasis in primary nasopharyngeal carcinoma (NPC): 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) and conventional work-ups (CWUs). Methods: All topic-related studies were comprehensively searched and included. We determined sensitivities and specificities across studies, calculated negative and positive likelihood ratios (LR- and LR+, respectively), and constructed summary receiver operating characteristic curves. Moreover, we compared the diagnostic performance of PET/CT and CWUs by analyzing studies that reported the results of these diagnostic methods on the same patients. Results: The pooled sensitivity and specificity were 85.7% and 98.1% for PET/CT (1474 patients), and 38.0% and 97.6% for CWUs (1329 patients). In the head-to-head comparison of PET/CT and CWUs (1029 patients), PET/CT showed a significantly higher sensitivity (83.7% vs. 40.1%, P < 0.001) and lower LR- (0.169 vs. 0.633, P < 0.001) than CWUs on a per-patient basis; no significant difference was observed in pooled specificity (97.7% vs. 97.8%, P = 0.892) or LR+ (36.416 vs. 16.845, P = 0.149). The superiority of PET/CT over CWUs was due mainly to the better diagnostic performance on bone metastasis. However, suboptimal sensitivity of PET/CT was reported in the aspect of detection of liver metastasis. Sensitivity analyses showed relatively poor sensitivity and LR- of PET/CT compared to the original analysis. Conclusions: PET/CT was superior to CWUs in detecting distant metastasis in primary NPC. However, the efficacy of PET/CT in detecting liver metastasis still requires further optimization.

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.

Prognostic Significance of Standardized Uptake Value on 18Fluorine-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Patients with Nasopharyngeal Carcinoma

The aim of this study was to investigate the prognostic significance of standardized uptake value (SUV) on 18 fluorine-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) in patients with nasopharyngeal carcinoma (NPC). Thirty-four patients who have histologically proven NPC and underwent ¹⁸F-FDG PET/CT were included in this study. After ¹⁸F-FDG PET/CT, all the patients received radiation therapy and 32 of them received concomitant weekly chemotherapy. The maximum SUV (SUV_max) at the primary tumor and the SUV_maxof the highest neck nodes were determined. The SUV_max-T ranged from 5.00 to 30.80 (mean: 15.37 ± 6.10) and there was no difference between SUV_max-T values for early and late stages (P = 0.99). The SUV_max-N ranged from 3.10 to 23.80 (mean: 13.23 ± 5.76). There was no correlation between SUV_max-T and SUV_max-N (r = 0.111, P = 0.532). There was no difference between the SUV_max-T and the positivity of neck lymph nodes (P = 0.169). The ability of SUV_maks-N to predict stage was obtained by a receiver operating characteristic (ROC) analysis. The area under the curve is 0.856 and the best cut-off value is 7.88. There was a good correlation between SUV_max-N and stage. While the mean SUV_max-T for the alive patients was slightly lower than that for the dead (14.65 ± 5.58 vs. 20.30 ± 7.92, P = 0.061), the difference between the groups was not statistically significant. Furthermore, there was no statistically significant difference for SUV_max-N between these two groups (P: 0.494). Cox-regression analysis showed that an increase in SUV_max-T and SUV_max-N was associated with death risk (relative risk [RR]: 1.13, P = 0.078 and RR: 1.052, P = 0.456, respectively). SUV_max-T and SUV_max-N were independent prognostic factors for survival in NPC patients. This will help the clinicians in choosing suitable candidates for more aggressive treatment modalities.

Is there an additive value of 18 F-FDG PET-CT to CT/MRI for detecting nodal metastasis in oropharyngeal squamous cell carcinoma patients with palpably negative neck?

Background Cervical node metastasis is one of the most significant prognostic factors in patients with oropharyngeal squamous cell carcinoma (SCC). There is little information regarding the comparison of histopathologic analysis following neck dissection with imaging results in oropharyngeal SCC. Purpose To investigate the clinical utility of PET-CT compared with computed tomography (CT) or magnetic resonance imaging (MRI) for detecting nodal metastasis in oropharyngeal SCC patients with palpably negative neck and to investigate whether pretreatment imaging modalities support the rationale for elective neck treatment. Material and Methods A total of 49 oropharyngeal SCC patients with palpably negative neck (42 men, 7 women; average age, 59.1 years) underwent primary tumor resection and neck dissection as a primary treatment. All patients were preoperatively evaluated with PET-CT and CT/MRI, and the diagnostic accuracy of each imaging modality was assessed by comparison with histopathologic results of the surgical specimen. Results Twenty-five (51.0%) of our 49 patients had neck metastases. On a level-by-level analysis, the sensitivity of PET-CT, CT/MRI, and a combination of PET-CT and CT/MRI was 54.6%, 54.6%, and 60.6%, respectively, at all neck levels. The area under the ROC showed that the diagnostic performance of the combined interpretation was not significantly different from that of CT/MRI alone (0.780 vs. 0.750, respectively; P = 0.158) and PET-CT alone (0.780 vs. 0.765, respectively; P = 0.501). Conclusion Addition of PET-CT to CT/MRI did not provide better diagnostic accuracy for detecting nodal metastasis in preoperative evaluation of oropharyngeal SCC patients with palpably negative neck, suggesting that current imaging studies might not replace elective neck dissection.

Combining plasma Epstein-Barr virus DNA and nodal maximal standard uptake values of 18F-fluoro-2-deoxy-D-glucose positron emission tomography improved prognostic stratification to predict distant metastasis for locoregionally advanced nasopharyngeal carcinoma

Background

This study aimed to evaluate the value of combining the nodal maximal standard uptake values (SUVmax) of ¹⁸ F-fluoro-2-deoxy-D-glucose positron emission tomography with Epstein-Barr virus DNA(EBV DNA) levels to predict distant metastasis for nasopharyngeal carcinoma (NPC) patients

Patients and Methods

Eight hundred seventy-four patients with stage III-IVa-b NPC were evaluated for the effects of combining SUVmax and EBV DNA levels on distant metastasis-free survival (DMFS), disease-free survival (DFS) and overall survival (OS).

Results

The optimal cutoff value was 6,220 copies/mL for EBV DNA and 7.5 for SUVmax-N. Patients with lower EBV DNA levels or SUVmax-N had a significantly better 3-year DMFS, DFS, and OS. Patients were divided into four groups based on EBV DNA and SUVmax-N, as follows: low EBV DNA and low SUVmax-N (LL), low EBV DNA and high SUVmax-N (LH), high EBV DNA and low SUVmax-N (HL), and high EBV DNA and high SUVmax-N (HH). There were significant differences between the four mentioned groups in 3-year DMFS: 95.7%, 92.2%, 92.3%, and 80.1%, respectively (P^trend < 0.001). When looking at the disease stage, the 3-year DMFS in group LL, LH, HL, HH were 94.2%, 92.9%, 95.0%, and 81.1%, respectively, in stage III patients (P^trend < 0.001) and 92.7%, 87.2%, 86.3%, and 77.0% in stage IVa–b patients (P^trend = 0.026).

Conclusion

Pretreatment EBV DNA and SUVmax of neck lymph nodes were independent prognostic factors for distant metastasis in NPC patients. Combining EBV DNA and SUVmax-N led to an improved risk stratification for distant metastasis in advanced-stage disease.

Use of PET in Head and Neck Cancers

Head and neck cancer imaging is especially necessary for staging. Computed tomography and magnetic resonance imaging are the techniques frequently used for this purpose. These methods are valuable for displaying detailed anatomical structures; however, they may be inadequate for making the distinction between recurrence, residual tumor, fibrosis, and normal tissues with an altered anatomy after treatments such as surgery, radiotherapy, and chemotherapy and for the detection of metastases. From this point, positron emission tomography may be a promising imaging method. Scanning the entire body with a single method is an important advantage of positron emission tomography. It may be useful in the detection of synchronous tumors, which are a serious problem in head and neck cancers. Positron emission tomography may provide additional contribution for neck metastases, where the primary site is unknown and is undetectable by other imaging techniques.

Pretreatment (18)F-FDG uptake heterogeneity can predict survival in patients with locally advanced nasopharyngeal carcinoma--a retrospective study

BACKGROUND

Intratumoural heterogeneity has been demonstrated to be a strong indicator of malignant transformation. Our study was to investigate pretreatment (18)F-FDG parameters, including (18)F-FDG based heterogeneity for predicting survival in patients with locally advanced nasopharyngeal carcinoma (NPC).

METHODS

Forty newly diagnosed, biopsy-proven locally advanced NPC patients who underwent (18)F-FDG PET/CT were retrospectively included. The following PET parameters were assessed: maximum and mean standardised uptake value (SUVmax and SUVmean), metabolic tumour volume (MTV), total lesion glycolysis (TLG) and intratumoral heterogeneity index (HI). The previous parameters were recorded both for the primary tumor (-T) and neck lymph nodes (-N). The following endpoints were evaluated: local control (LC), progression-free survival (PFS) and overall survival (OS). The survival analyses were performed using the Kaplan-Meier method. Univariate analysis was performed using the log-rank test.

RESULTS

Patients with a lower HI-T, SUVmax-T, SUVmean-T and TLG-T had significantly better 2-year LC. In predicting PFS, we found that both lower HI-T and HI-N had significantly better prognosis. However, the OS was only statistically associated with HI-T.

CONCLUSION

(18)F-FDG based heterogeneity appears to be an potential predicator of patient survival after treatment.

Evaluation of scoring systems and prognostic factors in patients with spinal metastases from nasopharyngeal carcinoma

BACKGROUND CONTEXT

The decision for operative treatment of patients with spinal metastases is dependent on the patient's predicted survival. Tokuhashi, Tomita, Bauer, and Oswestry scores have been devised for survival prediction; however, none of these systems have been evaluated in nasopharyngeal carcinoma (NPC).

PURPOSE

To investigate the accuracy of these scoring systems in predicting survival and to identify prognostic factors for survival of the patients with spinal metastases from NPC.

STUDY DESIGN

Retrospective analysis of the patients with spinal metastases from NPC who were treated in our institution.

PATIENT SAMPLE

The study included 87 patients with spinal metastases from NPC.

OUTCOME MEASURES

The primary outcome measure was the survival time of these patients. The potential prognostic factors that are known to influence survival such as general condition, extraspinal bone metastases, vertebral bone metastases, visceral metastases, and neurologic assessment based on Frankel score were also studied.

METHODS

The predicted survival according to the four scoring systems were calculated and labeled as "A" scores. These patients were then rescored by assigning NPC as a good prognostic tumor and labeled as "B" scores. The predicted survival of scores A and B were compared with actual survival. Potential prognostic factors of survival were investigated using univariate and multivariate Cox regression analyses. For all scoring systems, Kaplan-Meier survival estimates and log-rank tests were done; the predictive values were calculated using postestimation after Cox regression analyses.

RESULTS

The median overall survival for the whole cohort was 13 (range 1-120) months. In multivariate analysis, general condition (p<.01), visceral metastases (p<.01), and vertebral metastases (p<.01) showed significant association with survival. The absolute score of all scoring systems was significantly associated with actual survival, which extended to the different prognostic subgroups of each scoring systems. Log-rank test revealed significant differences in survival between the different prognostic subgroups of all scoring systems (p<.01). Predictive value of survival by modified Tokuhashi score was the highest among all four scoring systems.

CONCLUSIONS

Patients with spinal metastases from NPC have relatively good survival prognosis. All four scoring systems could be used to prognosticate these patients. The modified Tokuhashi score is the best in doing so.

Meta-analysis of diagnostic value of 18F-FDG PET or PET/CT for detecting lymph node and distant metastases in patients with nasopharyngeal carcinoma

OBJECTIVE

We performed this meta-analysis to comprehensively assess the diagnostic performance of positron emission tomography (PET) or PET/CT for detecting lymph node and distant metastases in patients with nasopharyngeal carcinoma (NPC).

METHODS

Through a search of four English and three Chinese databases (January 1990 to June 2013), pooled estimated sensitivity, specificity and diagnostic odds ratio (DOR) were calculated based on the data extracted from the included studies. We also constructed summary receiver operating characteristic curves, with the area under the curve (AUC) and obtained the Q* index. Heterogeneity and subgroup analysis were also performed.

RESULTS

In total, 18 articles consisting 20 studies were included in this meta-analysis. On a per-patient basis, the overall pooled estimates for sensitivity and specificity of PET or PET/CT in N and M staging of NPC were 0.89 [95% confidence interval (CI), 0.86-0.91] and 0.96 (95% CI, 0.95-0.96), respectively. The overall DOR, AUC and Q* index were 162.07 (95% CI, 90.72-289.55), 0.9689 and 0.9181, respectively. Subgroup analysis showed that AUC and Q* index were 0.9734 and 0.9255 for N staging and 0.9715 and 0.9223 for M staging, respectively.

CONCLUSION

The present meta-analysis showed that PET or PET/CT has excellent diagnostic performance for detecting lymph node and distant metastases in patients with NPC.

ADVANCES IN KNOWLEDGE

To provide evidence to assess the role of PET or PET/CT in staging of NPC.

Is 18F-FDG PET/CT more reliable than 99mTc-MDP planar bone scintigraphy in detecting bone metastasis in nasopharyngeal carcinoma?

OBJECTIVE

Bone metastasis occurs frequently in nasopharyngeal carcinoma (NPC) patients. The aim of this study was to compare the clinical value of 18F-FDG PET/CT with that of 99mTc-MDP planar bone scintigraphy (PBS) for detecting bone metastasis in NPC patients.

METHODS

Thirty-five histologically proven NPC patients were enrolled in this retrospective study. They underwent both 18F-FDG PET/CT and PBS within 7 days in our department. In a lesion-based analysis, the skeletal system, excluding the head, was divided into four regions: the spine, the pelvis, the thorax, and the appendix. Bone metastasis was considered to be present by either biopsy or clinical follow-up for at least 6 months. PET/CT and PBS were compared by McNemar's paired-sample test.

RESULTS

A total of 50 lesions were confirmed to be malignant (spine 27, thorax 11, pelvis 8 and appendix 4). Although PET/CT was found to be more sensitive on lesion level than PBS (sensitivity 70.0 versus 42.0%; P=0.044), there were still 14 metastatic (28.0%) lesions that could be detected by PBS while negative in PET/CT imaging. In a patient-based analysis, fifteen (42.9%) of 35 eligible patients were found to have bone metastasis. The sensitivity, specificity and accuracy of PET/CT was 60.0% (9/15), 100% (20/20) and 82.9% (29/35); as for PBS, it was 66.7% (10/15), 85.0% (17/20) and 77.1% (27/35), respectively. There was no statistical difference between PET/CT and PBS (P>0.05).

CONCLUSIONS

PBS, as a conventional imaging, should be used as an important complement for detecting bone metastasis in NPC patients.

Prospective Study of Tailoring Whole-Body Dual-Modality [18F]Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography With Plasma Epstein-Barr Virus DNA for Detecting Distant Metastasis in Endemic Nasopharyngeal Carcinoma at Initial Staging

Purpose

To evaluate which patients with nasopharyngeal carcinoma (NPC) obtained the greatest benefits from the detection of distant metastasis with [18F]fluorodeoxyglucose positron emission tomography and computed tomography (PET/CT) combined with plasma Epstein-Barr virus (EBV) DNA levels.

Patients and Methods

Consecutive patients with NPC were prospectively enrolled. PET/CT, conventional work-up (CWU), and quantification of plasma EBV DNA were performed before treatment. The accuracy of these strategies for distant metastases was assessed. The costs of the diagnostic strategies were compared.

Results

Eighty-six (14.8%) of the 583 eligible patients were found to have distant metastases; 71 patients (82.6%) by PET/CT and 31 patients (36.0%) by CWU. In the multivariable analysis, advanced N stage (odds ratio, 2.689; 95% CI, 1.894 to 3.818) and pretreatment EBV DNA level (odds ratio, 3.344; 95% CI, 1.825 to 6.126) were significant risk factors for distant metastases. PET/CT was not superior to CWU for detecting distant metastases in very low–risk patients (N0-1 with EBV DNA < 4,000 copies/mL; P = .062), but was superior for the low-risk patients (N0-1 with EBV DNA ≥ 4,000 copies/mL and N2-3 with EBV DNA < 4,000 copies/mL; P = .039) and intermediate-risk patients (N2-3 disease with EBV DNA ≥ 4,000 copies/mL; P < .001). The corresponding patient management changes based on PET/CT were 2.9%, 6.3%, and 16.5%, respectively. The costs per true-positive case detected by PET/CT among these groups were ¥324,138 (≈$47,458), ¥96,907 (≈$14,188), and ¥34,182 (≈$5,005), respectively.

Conclusion

PET/CT detects more distant metastases than conventional staging in patients with NPC. The largest benefit in terms of cost and patient management was observed in the subgroup with N2-3 disease and EBV DNA ≥ 4,000 copies/mL.

Prognostic implications of post-therapy (18)F-FDG PET in patients with locoregionally advanced nasopharyngeal carcinoma treated with chemoradiotherapy

OBJECTIVES

Reliable prognostic factors that serve as a guide to follow-up of patients with locoregionally advanced nasopharyngeal carcinoma (NPC) have not yet been identified. We sought to investigate the prognostic implications of post-therapy PET in patients with NPC treated with chemoradiotherapy.

METHODS

Patients with locoregionally advanced NPC (stages III and IVa-b) who had completed primary curative treatment for 3 months were eligible. All of the patients underwent (18)F-FDG PET and conventional work-up (CWU) for the assessment of treatment response.

RESULTS

A total of 165 patients were enrolled. Over a median follow-up of 58 months, 30 patients died and 41 had disease recurrence. The results of the 3-month post-therapy PET and total lesion glycolysis (TLG) of the primary tumor were independent predictors of overall survival. TNM tumor stage, TLG, and post-therapy PET findings were independently associated with disease-free survival (DFS). The results of post-therapy PET were more predictive of DFS than TNM tumor stage (P < 0.001 vs. P = 0.005). Among patients with stage IVa-b disease, there was a trend toward better 5-DFS rates in patients with a complete metabolic response (CMR) on PET than in those who showed a complete response in the CWU (5-year DFS = 70.7 vs. 63.1 %). Notably, the 1- and 2-year DFS rates were significantly better in the former group compared with the latter. In contrast, the results of post-therapy CWU were not a reliable predictor for DFS.

CONCLUSION

The results of post-therapy PET are an important independent prognostic factor in locoregionally advanced NPC. CMR on PET is associated with better DFS rates and could serve as a guidance to individualize the surveillance protocols for patients with stage IVa-b disease.

Accuracy of whole-body FDG-PET and FDG-PET/CT in M staging of nasopharyngeal carcinoma: a systematic review and meta-analysis

BACKGROUND

A meta-analysis was conducted to evaluate the accuracy of whole-body positron emission tomography (PET) or PET/CT in M staging of nasopharyngeal carcinoma (NPC).

METHODS

Through a search of relevant English language studies from October 1996 to September 2011, pooled estimated sensitivity, specificity, positive likelihood ratios, negative likelihood ratios, and summary receiver operating characteristic (SROC) curves of whole-body PET or PET/CT in M staging of NPC were calculated.

RESULTS

Three PET and 5 PET/CT studies were identified. The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of FDG-PET or PET/CT were 0.83 (95% confidence interval [CI], 0.77-0.88), 0.97 (95% CI, 0.95-0.98), 23.38 (95% CI, 16.22-33.69), and 0.19 (95% CI, 0.13-0.25), respectively. The area under curve was 0.9764 and Q* index estimate was 0.9307 for FDG-PET or PET/CT.

CONCLUSION

Current evidence confirms the good diagnostic performance of the whole-body FDG-PET or PET/CT in M staging of NPC.

Pretreatment (18)F-FDG PET standardized uptake value of primary tumor and neck lymph nodes as a predictor of distant metastasis for patients with nasopharyngeal carcinoma

OBJECTIVES

To evaluate the prognostic value of maximum standardized uptake value (SUVmax) measured in [(18)F]-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) for patients with non-disseminated nasopharyngeal carcinoma (NPC).

MATERIALS AND METHODS

From January 2002 to July 2008, 371 NPC patients who underwent (18)F-FDG-PET before radical intensity-modulated radiotherapy (IMRT) were recruited. The SUVmax was recorded for the primary tumor (SUVmax-T) and neck lymph nodes (SUVmax-N).

RESULTS

The median follow-up was 64months. The optimal cutoff value was 9.3 for SUVmax-T and 7.4 for SUVmax-N. Patients with a lower SUVmax-T or SUVmax-N had a significantly better 5-year distant metastasis-free survival (DMFS), but showed no significant difference in local control or regional control. Patients were divided into four groups by SUVmax, as follows: (a) both lower SUVmax-T and SUVmax-N, (b) higher SUVmax-T only, (c) higher SUVmax-N only, and d) both higher SUVmax-T and SUVmax-N. There were significant differences between these four groups in 5-year DMFS: (a) 95.5%, (b) 90.0%, (c) 83.3%, and (d) 79.9%, respectively (p=0.004). When looking at the stage of disease, the 5-year DMFSs in group a, b, c, d were 96.9%, 94.6%, 97.4%, and 84.3%, respectively in stage I-III patients (p=0.037) and were 91.6%, 82.9%, 68.5%, and 76.7% in stage IVA-B patients (p=0.145). Using multivariate analysis, the SUVmax grouping, gender, and stage were independent factors for DMFS.

CONCLUSION

The SUVmax of the primary tumor and neck lymph nodes were independent prognostic factors for DMFS in NPC patients treated with IMRT.

Evidence-based guideline recommendations on the use of positron emission tomography imaging in head and neck cancer

AIMS

To provide evidence-based practice guideline recommendations on the use of fluoro-2-deoxy-D-glucose positron emission tomography (PET) for diagnosis, staging and assessing treatment response, restaging or recurrence of head and neck cancer.

MATERIALS AND METHODS

A systematic review by Facey et al. (Health Technology Assessment 2007;11(44):iii-iv, xi-267) was used as the evidence base for recommendation development. As the review was limited to August 2005, the evidence base was updated to July 2011 using the same search strategies for MEDLINE and EMBASE used in the original review. The authors of the current systematic review drafted recommendations, which were reviewed, adapted and accepted by consensus by the Ontario provincial Head and Neck Disease Site Group and a special meeting of clinical experts.

RESULTS

The results of the Facey et al. review for head and neck cancer included five other systematic reviews and 31 primary studies. The 2005 to 2011 update search included four additional systematic reviews and 53 primary studies. Recommendations were developed based on this evidence and accepted by consensus.

CONCLUSIONS

PET is recommended in the M and bilateral nodal staging of all patients with head and neck squamous cell carcinoma where conventional imaging is equivocal, or where treatment may be significantly modified. PET is recommended in all patients after conventional imaging and in addition to, or prior to, diagnostic panendoscopy where the primary site is unknown. PET is recommended for the staging and assessment of recurrence of patients with nasopharyngeal carcinoma if conventional imaging is equivocal. PET is recommended for restaging patients who are being considered for major salvage treatment, including neck dissection.

Utility of 18F-fluoride PET/CT and 18F-FDG PET/CT in the detection of bony metastases in heightened-risk head and neck cancer patients

This study compared the diagnostic accuracy of (18)F-FDG PET/CT with that of (18)F-fluoride PET/CT in the detection of bony metastases in heightened-risk head and neck cancer patients.

METHODS

The study participants underwent (18)F-FDG PET/CT and (18)F-fluoride PET/CT within 2 wk of each another.

RESULTS

A total of 98 bony metastases were found in 18 of our 80 patients. (18)F-fluoride PET/CT and (18)F-FDG PET/CT showed similar lesion-based sensitivity (69.4% vs. 57.1%, P = 0.126) and areas under the curve (0.7561 vs. 0.7959, P = 0.149). Their combined interpretation demonstrated a significantly greater sensitivity and areas under the curve than that obtained with either modality alone (P < 0.001) in lesion-based analysis but not in patient-based analysis, with a treatment strategy change in 2 patients.

CONCLUSION

(18)F-fluoride PET/CT is a feasible modality for detecting bony metastases in patients with head and neck cancers, with similar sensitivity to (18)F-FDG PET/CT. Their combined use may not be justifiable.

The role of 18F-FDG PET/CT metabolic tumour volume in predicting survival in patients with metastatic nasopharyngeal carcinoma

OBJECTIVES

To investigate the role of PET-derived imaging markers in predicting metastatic nasopharyngeal carcinoma (NPC) outcomes.

MATERIALS AND METHODS

A total of 56 patients with metastatic NPC were enrolled. Before treatment, all of the participants underwent (18)F-FDG PET/CT. The following (18)F-FDG PET parameters were assessed: standardised uptake value, metabolic tumour volume (MTV), and total lesion glycolysis. Multivariate Cox proportional hazards models were used to identify the independent predictors of survival.

RESULTS

The multivariate analysis showed that performance status>1 (P=0.007), Epstein-Barr virus (EBV) DNA titre>5000 copies/mL (P=0.001), and MTV>110 mL (P=0.013) were independent risk factors for progression-free survival (PFS). Male sex (P=0.004), performance status>1 (P<0.0001), EBV DNA level>5000 copies/mL (P<0.0001), and MTV>110 mL (P=0.003) independently predicted overall survival (OS). The 2-year PFS and OS rates of the patients with MTV≤110 mL were 23.2% and 43%, respectively, compared with 0% and 9.1%, respectively, for those with MTV>110 mL. Combining the MTV with the EBV DNA titre allowed further survival stratification by dividing the patients into three groups with distinct PFS (2-year rates=30.8%, 7.1%, and 0%, P<0.0001) and OS (2-year rates=68.4%, 40%, and 0%, P<0.0001) rates.

CONCLUSION

The MTV appears to be an independent risk factor in metastatic NPC patients. This factor is complementary to the EBV DNA titre for predicting survival in metastatic NPC.

A rare case of breast cancer metastasising to the nasopharynx and paranasal sinuses

INTRODUCTION

Metastatic spread from non-head and neck tumours to the sinonasal region is exceedingly rare. We present a case of breast cancer metastasis to the nasopharynx, ethmoid and sphenoid sinuses. To date there have been only two similar cases in the literature. We discuss the diagnosis and management of such cases and propose how they may be staged.

PRESENTATION OF CASE

A 75-year-old woman with past medical history of breast carcinoma, presented clinically as having a primary sinonasal malignancy. Magnetic resonance imaging (MRI) demonstrated a lesion involving the spenoid and ethmoid sinuses, nasendoscopy revealed a mass in the nasopharynx. Biopsy from clinic pointed to inverted sinonasal papilloma, however this did not fit with the MRI or the clinical picture. Repeat biopsy under image guidance revealed the lesion to be a breast cancer metastasis.

DISCUSSION

An extensive literature review revealed few cases of spread to the sinonasal region from distant primary malignancy. When such cases do arise, most are from renal tumours. Breast cancer metastases usually present with signs and symptoms of disseminated disease, however our case represents a true isolated metastasis. We discuss the management of our case and suggest the use of the tumour-node-metastasis (TNM) system, in order to stage these rare isolated occurrences.

CONCLUSION

If discovered early, this rare manifestation may be managed by primary surgical resection. Metastases to the region may be more common than previously thought. A high index of suspicion should be employed, especially where there is past medical history of malignancy.

PET/CT for staging and follow-up of pediatric nasopharyngeal carcinoma

PURPOSE

While FDG PET/CT for the evaluation of nasopharyngeal carcinoma (NPC) in adult patients has documented advantages and disadvantages compared with conventional imaging, to our knowledge, no studies of FDG PET/CT for the evaluation of NPC in pediatric patients have been performed. In this investigation, we studied the utility of FDG PET/CT in children with NPC.

METHODS

The study group comprised 18 children with biopsy-proven NPC who underwent FDG PET/CT and MRI (total 38 pairs of images). All baseline and follow-up FDG PET/CT and MRI studies were independently reviewed for restaging of disease.

RESULTS

The concordance between FDG PET/CT and MRI in T, N, and overall staging was 29%, 64%, and 43%, respectively. Compared with MRI, FDG PET/CT yielded lower T and overall staging and showed less cervical and retropharyngeal lymphadenopathy. The concordance between follow-up FDG PET/CT and MRI was 79% overall and 100% 9 months after therapy. In patients who achieved complete remission, FDG PET/CT showed disease clearance 3-6 months earlier than MRI. There were no false-positive or false-negative FDG PET/CT scans during follow-up.

CONCLUSION

FDG PET/CT may underestimate tumor extent and regional lymphadenopathy compared with MRI at the time of diagnosis, but it helps to detect metastases and clarify ambiguous findings. FDG PET/CT is sensitive and specific for follow-up and enables earlier determination of disease remission. FDG PET/CT is a valuable imaging modality for the evaluation and monitoring of NPC in pediatric patients.

Prognostic significance of 18F-FDG PET parameters and plasma Epstein-Barr virus DNA load in patients with nasopharyngeal carcinoma

The plasma concentration of Epstein-Barr virus (EBV) DNA is associated with tumor burden and prognosis in patients with nasopharyngeal carcinoma (NPC), but data on the relationship between viral load and (18)F-FDG PET functional parameters are lacking. We examined the association of (18)F-FDG PET functional parameters and EBV DNA load with the clinicopathologic characteristics and clinical outcomes of patients with NPC.

METHODS

One hundred eight patients with NPC who underwent (18)F-FDG PET before treatment were included in this study. We determined total lesion glycolysis (TLG) of the primary tumor, the cervical nodes, and their combination and the maximal standardized uptake value of the primary tumor and cervical lymph nodes. EBV DNA was measured by real-time polymerase chain reaction.

RESULTS

EBV DNA was significantly associated with total TLG (R(2) = 0.589). Total TLG values had the highest correlation with EBV DNA load and were significantly associated with tumor, nodal, and overall stages. However, tumor TLG greater than the median (>65 g) was the only parameter significantly associated with overall, local recurrence-free, disease-free, and distant metastasis-free survivals (P = 0.033, 0.014, <0.001, and 0.023, respectively). After allowance for potential confounders, tumor TLG retained its independent significance for overall and disease-free survival rates (P = 0.045 and 0.006, respectively).

CONCLUSION

Total TLG values are primarily associated with tumor burden and clinical stage, whereas tumor TLG is the best predictor of patient survival after treatment.