Up-front PET/CT changes treatment intent in patients with head and neck squamous cell carcinoma

Diagnostic Accuracy of Up-Front PET/CT and MRI for Detecting Cervical Lymph Node Metastases in T1-T2 Oral Cavity Cancer-A Prospective Cohort Study

The diagnostic accuracy of up-front 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) for detecting cervical lymph node metastases in patients with T1-T2 oral squamous cell carcinoma is reported with large discrepancies across the literature. We investigated the sensitivity, specificity, positive and negative predictive value, and accuracy of up-front PET/CT for detecting cervical lymph node metastases in this patient group and compared the performance to magnetic resonance imaging (MRI). In this prospective cohort study, 76 patients with T1-T2 oral squamous cell carcinoma underwent an up-front PET/CT and MRI at the Odense University Hospital from September 2013 to February 2016. Sentinel node biopsy and elective neck dissection were used for histopathological verification of the imaging modalities. Up-front PET/CT was significantly more sensitive than neck MRI (74% vs. 27%, p = 0.0001), but less specific (60% vs. 88%, p = 0.001). The accuracy of PET/CT and neck MRI was comparable (66% vs. 63%, p = 0.85), the PPV was slightly in favor of neck MRI (56% vs. 62%, p = 0.73), the NPV was slightly in favor of PET/CT (77% vs. 63%, p = 0.16). Neither PET/CT nor neck MRI should stand alone for N-staging T1-T2 oral cavity cancer.

Utilization of PET/CT Scan in Head and Neck Carcinoma: A Tertiary Care Hospital Experience

Objective

PET/CT scan has been increasingly used in assessment of Head and Neck cancer prior to treatment for evaluation and for surveillance. In this study we aim to assess the utilization of PET/CT scan at a tertiary care hospital.

Methods

Retrospectively data was reviewed of all patients of Head and Neck cancer who underwent PET/CT scan for workup or for follow-up between July 2018 and December 2019. PET/CT scan done in the pre-treatment assessment and post-treatment surveillance were analyzed for its utility.

Results

A total of 145 patients were included. The main indication for pre-treatment PET/CT scan was loco-regionally advanced disease (62 of 90 patients, 68.8%). No specific indication was noted in 19 patients (21%). A significant change in treatment decision was seen in pre-treatment patients based on M stage following a PET/CT scan. However, no change was noted on the basis of T or N stage. In the post-treatment surveillance there was a significant correlation of type of recurrence with clinical assessment and indication for PET/CT scan. 37 out of 87 patients (42.5%) underwent PET/CT scan for no specific reason, of which, 07 patients (18.9%) were detected to have distant metastasis.

Conclusion

Role of PET/CT in the pre-treatment assessment is very limited and maybe confined to advanced local or regional disease. Post-treatment surveillance with PET/CT scan has a promising role and must be done as a baseline during 1st follow up at 03 months in all patients who have advanced disease and have undergone multi-modality treatment for the same.

The impact of multimodality integrated positron emission tomography-computed tomography on improving the staging and management of head and neck malignancy: a cross- sectional study

BACKGROUND

Clinical assessment of head and neck cancers is highly challenging owing to the complexity of regional anatomy and wide range of lesions. The diagnostic evaluation includes detailed physical examination, biopsy and imaging modalities for disease extent and staging. Appropriate imaging is done to enable determination of precise tumor extent and involvement of lymph nodes, and detection of distant metastases and second primary tumors.

OBJECTIVE

To evaluate the initial staging discrepancy between conventional contrasted computed tomography (CT) and 18F-fluorodeoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) and its impact on management plans for head and neck malignancies.

DESIGN AND SETTING

Prospective cross-sectional study in two tertiary-level hospitals.

METHODS

This study included 30 patients with primary head and neck malignant tumors who underwent contrasted computed tomography and whole-body 18F-FDG PET/CT assessments. The staging and treatment plans were compared with the incremental information obtained after 18F-FDG PET/CT.

RESULTS

18F-FDG PET/CT was found to raise the stage in 33.3% of the cases and the treatment intent was altered in 43.3% of them, while there was no management change in the remaining 56.7%. 18F-FDG PET/CT had higher sensitivity (96% versus 89.2%) and accuracy (93% versus 86.7%) than conventional contrast-enhanced computed tomography.

CONCLUSION

Our study demonstrated that 18F-FDG PET/CT had higher sensitivity and accuracy for detecting head and neck malignancy, in comparison with conventional contrast-enhanced computed tomography. 18F-FDG PET/CT improved the initial staging and substantially impacted the management strategy for head and neck malignancies.

Diagnostic Accuracy of Combined PET/CT with MRI, 18F-FDG PET/MRI, and 18F-FDG PET/CT in Patients with Oropharyngeal and Hypopharyngeal Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

Introduction

The aim of this paper is to compare the diagnostic accuracy of PET/CT, PET/MRI, and the combination of PET/CT and MRI for detecting synchronous cancer and distant metastasis in patients with oropharyngeal and hypopharyngeal squamous cell carcinomas (OHSCC).

Method

A large and growing body of literature has been conducted using the Preferred Reporting Items for Systematic Reviews (PRISMA). The researchers collected all accessible literature existing through Cochrane Library (John Wiley & Sons) electronic databases, Embase (Elsevier), PubMed (U.S. National Library of Medicine), Scopus, and Google Scholar up to June 2020. Analyses were conducted using Stata version 12.0 (StataCorp LP).

Results

A total of nine studies consisting of 1166 patients were included. The pooled sensitivity of combined PET/CT with MRI, 18F-FDG PET/MRI, and 18F-FDG PET/CT was 0.92, 0.80, and 0.79, respectively, and the corresponding specificities were 0.93, 0.91, and 0.88. The overall prevalence of distant metastases and synchronous cancer in patients with oropharyngeal and hypopharyngeal squamous cell carcinomas was 9.2% and 11.8%, respectively, with the esophagus (4.6%) being the most common site of synchronous cancer. The most common sites of distant metastases were lung (3%), bone (1.2%), and distant lymph nodes (1.2%), respectively.

Conclusion

Our study showed an approximately similar diagnostic performance for PET/CT, PET/MRI, and the combination of PET/CT and MRI for metastasis assessment in advanced oropharyngeal and hypopharyngeal squamous cell carcinomas.

Diagnostic accuracy of imaging modalities in detection of histopathological extranodal extension: A systematic review and meta-analysis

OBJECTIVE

To present an up to date systematic review and meta-analysis evaluating the diagnostic accuracy of the most used imaging modalities in detection of histopathological extra nodal extension (ENE) in head and neck squamous cell carcinoma.

MATERIALS AND METHODS

Medline, Embase, and Cochrane databases were systematically searched on March 27th 2020. Screening, inclusion, quality assessment, and data extraction were done by two reviewers. Meta-analysis was conducted using the bivariate model approach after pooling the studies according to imaging modality. Heterogeneity was explored by meta-regression. Comparison was done by meta-regression and sub-group analyses.

RESULTS

Out of 476 initial hits, 25 studies were included for analysis. Of these, 14 dealt with CT, nine with PET/CT, four with MRI, two with ultrasound, and none with PET/MRI. Meta-analysis based on a total sample size of 3391 showed that CT had a sensitivity of 76% [67-82%] and specificity of 77% [69-83%], MRI a sensitivity of 72% [64-79%] and specificity of 78% [57-90%], and PET/CT a sensitivity of 80% [76-84%] and specificity of 83% [74-90%] in the ability to predict ENE. No meta-analysis could be done on ultrasound. There were no significant differences between modalities in overall accuracy; however, PET/CT had significantly higher sensitivity than CT and MRI.

CONCLUSION

There was no significant difference in the ability of CT, MRI, and PET/CT to diagnose histopathological ENE, except that PET/CT had a significantly higher sensitivity than CT and MRI.

Imaging for Target Delineation in Head and Neck Cancer Radiotherapy

The definition of tumor involved volumes in patients with head and neck cancer poses great challenges with the increasing use of highly conformal radiotherapy techniques eg, volumetric modulated arc therapy and intensity modulated proton therapy. The risk of underdosing the tumor might increase unless great care is taken in the process. The information gained from imaging is increasing with both PET and MRI becoming readily available for the definition of targets. The information gained from these techniques is indeed multidimensional as one often acquire data on eg, metabolism, diffusion, and hypoxia together with anatomical and structural information. Nevertheless, much work remains to fully exploit the available information on a patient-specific level. Multimodality target definition in radiotherapy is a chain of processes that must be individually scrutinized, optimized and quality assured. Any uncertainties or errors in image acquisition, reconstruction, interpretation, and delineation are systematic errors and hence will potentially have a detrimental effect on the entire radiotherapy treatment and hence; the chance of cure or the risk of unnecessary side effects. Common guidelines and procedures create a common minimum standard and ground for evaluation and development. In Denmark, the treatment of head and neck cancer is organized within the multidisciplinary Danish Head and Neck Cancer Group (DAHANCA). The radiotherapy quality assurance group of DAHANCA organized a workshop in January 2020 with participants from oncology, radiology, and nuclear medicine from all centers in Denmark, treating patients with head and neck cancer. The participants agreed on a national guideline on imaging for target delineation in head and neck cancer radiotherapy, which has been approved by the DAHANCA group. The guidelines are available in the Supplementary. The use of multimodality imaging is being recommended for the planning of all radical treatments with a macroscopic tumor. 2-[¹⁸F]FDG-PET/CT should be available, preferable in the treatment position. The recommended MRI sequences are T1, T2 with and without fat suppression, and T1 with contrast enhancement, preferable in the treatment position. The interpretation of clinical information, including thorough physical examination as well as imaging, should be done in a multidisciplinary setting with an oncologist, radiologist, and nuclear medicine specialist.

Upfront PET/CT affects management decisions in patients with recurrent head and neck squamous cell carcinoma

PURPOSE

To compare multidisciplinary team conference (MDTC) decisions regarding treatment intent based on either chest X-ray + MRI of the head and neck (CXR/MRI) or ¹⁸F-FDG-PET/CT (PET/CT) in patients with recurrent head and neck squamous cell carcinoma (HNSCC).

METHODS

Prospective blinded cohort study based on paired data. Consecutive patients with suspected recurrent HNSCC were invited to participate. All included patients underwent CXR/MRI and PET/CT before diagnostic biopsy. An ordinary MDTC using all available imaging data was conducted as per standard practice. After at least three months (to eliminate recall bias in the team), the first project MDTC, based on either CXR/MRI or PET/CT, was conducted, and the tumor board made conclusions regarding treatment. After an additional three months, a second project MDTC was conducted using the complementary imaging strategy. The separate treatment strategies were compared using McNemar's test.

RESULTS

A total of 110 patients (90 males and 20 females, median age 66 years, range 40-87) were included. The initial primary tumor originated from the pharynx in 56 (51%) patients, oral cavity in 17 (15%) patients, and larynx in 37 (34%) patients. Based on CXR/MRI, 87 patients (79%) were recommended curative treatment and 23 (21%) palliative treatment. Based on PET/CT, the MDTC decided that 52 (47%) patients were suitable for curative treatment and 58 (53%) for palliative treatment. The absolute difference of 32% was statistically significant (95% CI: 22-42%, p < 0.001).

CONCLUSIONS

PET/CT affected MDTC decisions in patients with recurrent HNSCC towards less curative and more palliative treatment.

PET/CT Versus Standard Imaging for Prediction of Survival in Patients with Recurrent Head and Neck Squamous Cell Carcinoma

The purpose of this study was to examine whether staging with ¹⁸F-FDG PET/CT better predicts survival in patients with recurrent head and neck squamous cell carcinoma (HNSCC) than chest x-ray (CXR) plus head and neck MRI or chest CT (CCT) plus head and neck MRI. Methods: This was a prospective cohort study based on paired data. Consecutive patients with histologically verified HNSCC recurrence were enrolled from September 2013 to March 2016. All patients underwent CXR/MRI, CCT/MRI, and PET/CT on the same day and before biopsy. All imaging studies underwent masked interpretation by separate teams of experienced nuclear physicians or radiologists. Recurrent carcinomas were categorized as localized (equivalent to primary stages I-II), locally advanced (equivalent to primary stages III-IVB), or metastatic (equivalent to primary stage IVC). Discriminative abilities for each imaging strategy with respect to cancer-specific and stage-based survival were compared using Kaplan-Meier analysis, Cox proportional-hazards regression with the Harrell concordance index (C-index), and net reclassification improvement. Results: In total, 110 patients (90 men and 20 women; median age, 66 y; range, 40-87 y) were included. PET/CT significantly changed the assigned tumor stage when compared with imaging strategies based on CXR/MRI or CCT/MRI (P < 0.001 for both). Kaplan-Meier analysis of PET/CT-based staging showed progressively worsened prognosis with localized, locally advanced, or metastatic disease (log-rank test, P < 0.001), whereas CXR/MRI and CCT/MRI were unable to distinguish between these groups in terms of survival (log-rank test, P = 0.18 and P = 0.58, respectively). Overall discriminative ability in predicting cancer-specific mortality was significantly greater for PET/CT (C-index, 0.72) than for CXR/MRI (C-index, 0.55) (P = 0.001) and CCT/MRI (C-index, 0.55)(P < 0.001). The addition of PET/CT to either CXR/MRI or CCT/MRI was associated with a significantly positive net reclassification improvement (P < 0.001 for both). Conclusion: Contrary to standard imaging strategies, PET/CT-based staging in recurrent HNSCC was able to significantly discriminate among the survival courses of patients with local, locally advanced, or metastatic disease and predict their respective survival probability.