Planned neck dissection after chemoradiotherapy in advanced oropharyngeal squamous cell cancer: The role of US, MRI and FDG-PET/TC scans to assess residual neck disease

Contrast-Enhanced Computed Tomography (CT) With Concordant Sonography as Sufficient Early Detection Tools for Recurrent and Persistent Cervical Metastases After (Chemo)radiotherapy (CRT)

BACKGROUND

Most challenging treatment needs are in recurrent or persisting head and neck squamous cell carcinoma (HNSCC) patients after (((chemo-)radiotherapy) (C)RT).

MATERIALS AND METHODS

This 10-year retrospective study included 100 patients, who initially received (C)RT followed by neck dissection (ND). The results of computed tomography (CT) and sonography were evaluated for residual/recurrent cervical lymph nodes and compared to the histopathology. On this basis we calculate the sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV).

RESULTS

A total of 144 ND specimens were analyzed. The combination of CT and sonography (n = 103) reached values 97% sensitivity, 71% specificity, 98% NPV, 66% PPV, and 81% overall accuracy. For patients who received as primary treatment CRT the values for the combined imaging were: 100.0%, 73.5%, 100.0%, 66.7% and 82.7% respectively.

CONCLUSION

Our study demonstrates that the combined use of CT and sonography reliably detects lymph node metastases, particularly in patients previously treated with CRT, even after a long time after treatment.

Comprehensive review of post-treatment imaging in head and neck cancers: from expected to unexpected and beyond

Head and neck cancer management requires multidisciplinary approach in which radical surgery with or without flap reconstructions and neck dissection, along with radiotherapy (RT)/chemoradiotherapy (CRT) serve as the key components. Neoadjuvant chemotherapy and immunotherapy are used in selected cases based on the institutional preference. Knowledge of expected post-treatment changes on imaging is essential to differentiate it from recurrence. In addition, awareness of various post-treatment complications is imperative for their early detection on imaging. Distorted anatomy after treatment poses diagnostic challenge, hence, proper choice of imaging modality and appropriate timing of scan is pertinent for accurate post-treatment evaluation. In this article, we have comprehensively reviewed expected post-treatment appearances and complications on imaging. We have discussed imaging appearances of recurrences at the primary and lymphnodal sites and discussed documentation of findings using Neck Imaging Reporting and Data Systems (NI-RADS). We have also delved into the patterns of recurrence in human papillomavirus (HPV) positive HNSCC. Furthermore, we have provided flowcharts and discussed recommendations on the site-specific and treatment-related imaging modalities to be used along with their appropriate timing, for adequate evaluation of HNSCC after treatment. In addition, we have also touched upon the role of advanced imaging techniques for post-treatment HNSCC evaluation.

Circulating HPV Tumor DNA and Molecular Residual Disease in HPV-Positive Oropharyngeal Cancers: A Scoping Review

The aim of this review is to assess the utility of circulating HPV tumor DNA (ctHPVDNA) clearance in the monitoring of molecular residual disease in HPV-related oropharyngeal squamous cell carcinoma (OPSCC) patients. Recently, ctHPVDNA in patient plasma was found to be a promising biomarker for HPV OPSCC. Changes in this biomarker appear to be associated with treatment response and may be useful for identifying molecular residual disease. A review of the literature was performed using PubMed/MEDLINE, EMBASE, and Cochrane Library databases according to the PRISMA criteria for scoping reviews (from 2017 to July 2024). A total of 5 articles and 562 patients have been included. Three studies examine the role of ctHPVDNA clearance in CRT, while the remaining two studies consider surgery as a treatment option. The results of this scoping review indicate that ctHPVDNA has a potential role to serve as a valuable biomarker in the assessment of molecular residual disease. Further studies are required to confirm the efficacy of this marker for stratifying this group of patients.

The Neck-Persistency-Net: a three-dimensional, convolution, deep neural network aids in distinguishing vital from non-vital persistent cervical lymph nodes in advanced head and neck squamous cell carcinoma after primary concurrent radiochemotherapy

PURPOSE

To evaluate the diagnostic performance (DP) of the high-resolution contrast computed tomography (HR-contrast-CT) based Neck-Persistency-Net in distinguishing vital from non-vital persistent cervical lymph nodes (pcLNs) in patients with advanced head and neck squamous cell carcinoma (HNSCC) following primary concurrent chemoradiotherapy (CRT) with [18F]-fluorodeoxyglucose positron emission tomography and high-resolution contrast-enhanced computed tomography ([18F]FDG-PET-CT). Furthermore, the Neck-Persistency-Net's potential to justify omitting post-CRT neck dissection (ND) without risking treatment delays or preventing unnecessary surgery was explored.

METHODS

All HNSCC patients undergoing primary CRT followed by post-CRT-ND for pcLNs recorded in the institutional HNSCC registry were analyzed. The Neck-Persistency-Net DP was explored for three scenarios: balanced performance (BalPerf), optimized sensitivity (OptSens), and optimized specificity (OptSpec). Histopathology of post-CRT-ND served as a reference.

RESULTS

Among 68 included patients, 11 were female and 32 had vital pcLNs. The Neck-Persistency-Net demonstrated good DP with an area under the curve of 0.82. For BalPerf, both sensitivity and specificity were 78%; for OptSens (90%), specificity was 62%; for OptSpec (95%), sensitivity was 54%. Limiting post-CRT-ND to negative results would have delayed treatment in 27%, 40%, and 7% for BalPerf, OptSens and OptSpec, respectively, versus 23% for [18F]FDG-PET-CT. Conversely, restricting post-CRT-ND to positive results would have prevented unnecessary post-CRT-ND in 78%, 60%, and 95% for BalPerf, OptSens and OptSpec, respectively, versus 55% for [18F]FDG-PET-CT.

CONCLUSION

The DP of the Neck-Persistency-Net was comparable to [18F]-FDG-PET-CT. Depending on the chosen decision boundary, the potential to justify the omission of post-CRT-ND without risking treatment delays in false negative findings or reliably prevent unnecessary surgery in false positive findings outperforms the [18F]-FDG-PET-CT.

The landscape of circulating tumor HPV DNA and TTMV-HPVDNA for surveillance of HPV-oropharyngeal carcinoma: systematic review and meta-analysis

BACKGROUND

Human papilloma virus (HPV) related cancers of the oropharynx are rapidly increasing in incidence and may soon represent the majority of all head and neck cancers. Improved monitoring and surveillance methods are thus an urgent need in public health.

MAIN TEXT

The goal is to highlight the current potential and limitations of liquid biopsy through a meta analytic study on ctHPVDNA and TTMV-HPVDNA. It was performed a Literature search on articles published until December 2023 using three different databases: MEDLINE, Embase, and Cochrane Library. Studies that evaluated post-treatment ctHPVDNA and TTMV-HPVDNA in patients with HPV + OPSCC, studies reporting complete data on the diagnostic accuracy in recurrence, or in which the number of true positives, false positives, true negatives, and false negatives was extractable, and methods of detection of viral DNA clearly defined. The meta-analysis was conducted following the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) reporting guidelines. The aim of this meta-analysis was to evaluate the sensitivity, specificity, and accuracy of ctHPVDNA and TTMV by ddPCR to define its efficacy in clinical setting for the follow up of HPV-OPSCC.

CONCLUSION

The 12 studies included in the meta-analysis provided a total of 1311 patients for the analysis (398 valuated with ctHPVDNA and 913 with TTMV-HPVDNA). Pooled sensitivity and specificity were 86% (95% CI: 78%-91%) and 96% (95% CI: 91%-99%), respectively; negative and positive likelihood ratios were 0.072 (95% CI: 0.057-0.093) and 24.7 (95% CI: 6.5-93.2), respectively; pooled DOR was 371.66 (95% CI: 179.1-918). The area under the curve (AUC) was 0.81 (95% CI, 0.67-0.91). Liquid biopsy for the identification of cell free DNA might identify earlier recurrence in HPV + OPSCC patients. At the present time, liquid biopsy protocol needs to be standardized and liquid biopsy cannot yet be used in clinical setting. In the future, a multidimensional integrated approach which links multiple clinical, radiological, and laboratory data will contribute to obtain the best follow-up strategies for the follow-up of HPV-OPSCC.

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.

It is time to improve the diagnostic workup of oropharyngeal cancer with circulating tumor HPV DNA: Systematic review and meta-analysis

The possibility of detecting circulating tumor HPV DNA (ctHPVDNA) in plasma in patients with oropharyngeal cancer has been demonstrated in several reports. However, these data are from small cohorts and available tests for detection of ctHPVDNA are not fully validated. The aim is to evaluate sensitivity, specificity, and accuracy of ctHPVDNA by ddPCR to define its efficacy in the clinical setting for the diagnosis of HPV + OPSCC. A comprehensive search of three different databases: MEDLINE, Embase, and Cochrane Library databases. A total of 998 patients were evaluated from the 13 studies. OPSSC p16+ were 729, while controls p16- were 269. The meta-analytic study estimated the diagnostic performance of ctHPVDNA as follows: pooled sensitivity and specificity of 0.90 (95% CI: 0.82-0.94) and 0.94 (95% CI: 0.85-0.98), respectively; positive and negative likelihood ratios of 12.6 (95% CI: 4.9-32.1) and 0.05 (95% CI: 0.02-0.13), respectively. ddPCR for ctHPVDNA has good accuracy, sensitivity, and specificity for diagnosis of HPV + OPSCC. ctHPVDNA kinetic represents a great reliable opportunity to improve diagnostic and therapeutic management of cancer patients and could open new perspectives for understanding tumor biology.

Management of Recurrent HPV-Positive Oropharyngeal Squamous Cell Carcinoma: a Contemporary Review

PURPOSE OF REVIEW

To review the impact of contemporary treatment strategies on salvage outcomes in patients with recurrent human papilloma virus-positive oropharyngeal squamous cell carcinoma (HPV + OPSCC).

RECENT FINDINGS

Secondary to HPV, changes in disease biology have impacted primary treatments and subsequent approaches to patients with recurrence. With treatment strategies more inclusive of upfront surgery, the characteristics of patients with recurrence HPV + OPSCC have been further redefined. Less invasive endoscopic surgical approaches such as transoral robotic surgery (TORS), and the continued refinement of conformal radiotherapy techniques, have improved treatment options for patients with recurrent HPV + OPSCC. Systemic treatment options have continued to expand including potentially effective immune-based therapies. Effective surveillance with systemic and oral biomarkers offers hope of earlier detection of recurrence. Management of patients with recurrent OPSCC remains difficult. Modest improvements in salvage treatment have been observed within the HPV + OPSCC cohort largely reflecting disease biology and improved treatment techniques.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Systematic review and meta-analysis of the diagnostic effectiveness of positron emission tomography-computed tomography versus magnetic resonance imaging in the post-treatment surveillance of head and neck squamous cell carcinoma

OBJECTIVE

There is currently no consensus on the ideal protocol of imaging for post-treatment surveillance of head and neck squamous cell carcinoma. This study aimed to consolidate existing evidence on the diagnostic effectiveness of positron emission tomography-computed tomography versus magnetic resonance imaging.

METHOD

Systematic electronic searches were conducted using Medline, Embase and Cochrane Library (updated February 2021) to identify studies directly comparing positron emission tomography-computed tomography and magnetic resonance imaging scans for detecting locoregional recurrence or residual disease for post-treatment surveillance.

RESULTS

Searches identified 3164 unique records, with three studies included for meta-analysis, comprising 176 patients. The weighted pooled estimates of sensitivity and specificity for scans performed three to six months post-curative treatment were: positron emission tomography-computed tomography, 0.68 (95 per cent confidence interval, 0.49-0.84) and 0.89 (95 per cent confidence interval, 0.84-0.93); magnetic resonance imaging, 0.72 (95 per cent confidence interval, 0.54-0.88) and 0.85 (95 per cent confidence interval, 0.79-0.89), respectively.

CONCLUSION

Existing studies do not provide evidence for superiority of either positron emission tomography-computed tomography or magnetic resonance imaging in detecting locoregional recurrence or residual disease following curative treatment of head and neck squamous cell carcinoma.

Dynamic contrast-enhanced MRI and Doppler sonography in patients with squamous cell carcinoma of head and neck treated with induction chemotherapy

In view of the inherent limitations associated with performing dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) in clinical settings, current study was designed to provide a proof of principle that Doppler sonography and DCE-MRI derived perfusion parameters yield similar hemodynamic information from metastatic lymph nodes in squamous cell carcinomas of head and neck (HNSCCs). Strong positive correlations between volume fraction of plasma space in tissues (V_p ) and blood volume (r = 0.72, p = 0.02) and between V_p and %area perfused (r = 0.65, p = 0.04) were observed. Additionally, a moderate positive correlation trending towards significance was obtained between volume transfer constant (K^trans ) and %area perfused (r = 0.49, p = 0.09).

Cell-Free Human Papillomavirus-DNA for Monitoring Treatment Response of Head and Neck Squamous Cell Carcinoma: Systematic Review and Meta-Analysis

OBJECTIVES/HYPOTHESIS

The aim of this study was to assess the value of cell-free human papillomavirus-DNA (cfHPV-DNA) as a diagnostic test for the post-treatment surveillance of patients with HPV-positive head and neck squamous cell carcinoma (HNSCC) through a systematic review and meta-analysis.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A literature search was conducted in three databases (MEDLINE, Embase, and Scopus) in January 2021. The population included patients with HPV-positive HNSCC. The intervention was the use of the repeated liquid biopsy with circulating HPV-DNA detection during follow-up. The outcome was to establish the value of cfHPV-DNA as a diagnostic test for the post-treatment surveillance of patients with HPV-positive HNSCC.

RESULTS

Ten studies included in the meta-analysis provided a total of 457 patients with HPV-positive HNSCC. The meta-analytic study estimated the diagnostic performance of cfHPV-DNA as follows: pooled sensitivity and specificity of 0.65 (95% confidence interval [CI]: 0.40-0.84) and 0.99 (99% CI: 0.96-0.99), respectively; positive and negative likelihood ratios of 62.5 (99% CI: 22.9-170.2) and 0.05 (99% CI: 0.013-0.24), respectively; and pooled diagnostic odds ratio of 371.66 (99% CI: 60.4-2286.7).

CONCLUSION

Currently, the follow-up protocol for HNSCC patients includes routine clinical evaluation and radiological imaging. Biomarkers to monitor this disease are not established. Considering its high specificity, cfHPV-DNA represents a potential confirmatory test in the case of positive positron emission tomography and computed tomography. In the near future, cfHPV-DNA could be used as a biomarker for monitoring the treatment response during the clinical trials of de-escalation therapy or immunotherapy. Larger sample sizes and the homologation of study protocols and methodology are needed to better establish its utility in the clinical practice. Laryngoscope, 2021.

External validation of nodal failure prediction models including radiomics in head and neck cancer

PURPOSE

To externally validate the previously published pre-treatment prediction models for lymph nodes failure after definitive radiotherapy in head and neck squamous cell carcinoma (HNSCC) patients.

MATERIALS AND METHODS

This external validation cohort consisted of 143 node positive HNSCC patients treated between July 2007 and June 2016 by curative radiotherapy with or without either cisplatin or cetuximab. Imaging and pathology reports during follow-up were analyzed to indicate persisting or recurring nodes. The previously established clinical, radiomic and combined models were validated on this cohort by assessing the concordance index (c-index) and model calibration.

RESULTS

Overall 113 patients with 374 pLNs were suitable for final analysis. There were 20 (5.3%) nodal failures from 15 patients after a median follow-up of 36.1 months. Baseline characteristics and radiomic features were comparable to the training cohort. Both the radiomic model (Least-axis-length of lymph node (LALLN) and correlation of gray level co-occurrence matrix (Corre-GLCM)) and the combined model (T stage, gender, WHO performance score, LALLN and Corre-GLCM) showed good agreement between predicted and observed nodal control probabilities. The radiomic (c-index: 0.71; 95% confidence interval (CI): 0.59-0.84) and combined (c-index: 0.71; 95% CI: 0.59-0.82) models performed better than the clinical model (c-index: 0.57; 95% CI: 0.47-0.68) on this cohort, with a significant difference between the combined and clinical models (z-score test: p = 0.005).

CONCLUSION

The combined model including clinical and radiomic features was externally validated and proved useful to predict nodal failures and could be helpful to guide treatment choices before and after curative radiation treatment for node positive HNSCC patients.

Surgical site complications of post-chemoradiotherapy neck dissection: Urgent need for standard registration

Nowadays, a substantial number of head and neck cancer patients are treated by organ-preserving chemoradiation (CRT), with a possible increased risk of complications after planned or salvage neck dissections. We try to determine the risk pattern of surgical site complications (SSC) post-CRT.

Response evaluation of cervical lymph nodes after chemoradiation in patients with head and neck cancer - does additional [18F]FDG-PET-CT help?

Background

Contrast-enhanced high-resolution computed tomography (contrast-CT) is a standard imaging modality following primary concurrent radiochemotherapy (RCT) for response evaluation in patients with head and neck squamous cell carcinoma (HNSCC). We investigated the additional benefit of Fluorine-18-fluorodeoxyglucose ([18F]FDG) - positron emission tomography with computed tomography (PET-CT), if complete response (CR) in the neck based on contrast-CT was considered unsafe by the interdisciplinary tumor board (ITB).

Methods

In a retrospective observational study, patients recorded in the institutional tumor registry with incident advanced HNSCC following first line treatment with RCT were eligible. If contrast-CT results of the neck were equivocal or positive at response evaluation, a neck dissection (ND) was scheduled. While waiting for the ND, a [18F]FDG-PET-CT was performed in addition. The histopathological outcome of ND served as reference criterion. Accuracy parameters including sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) for both, contrast-CT and PET-CT, served as main outcome parameters.

Results

A total of 41 HNSCC patients with positive or equivocal posttreatment contrast-CT were eligible for post-RCT-ND. Of these, 33 received an additional [18F]FDG-PET-CT prior to surgery. Median interval between completion of RCT and the ([18F]FDG)-PET-CT was 10 weeks. Vital persistent tumor in the neck was histopathologically found in 13 of 33 patients with positive or equivocal posttreatment contrast-CT. For contrast-CT and [18F]FDG-PET-CT, sensitivity was 92.3 and 69.2% and did not differ statistically significantly (p = 0.250) whereas specificity was significantly higher for [18F]FDG-PET-CT compared with contrast-CT (80% vs. 25%, p = 0.001). For contrast-CT and [18F]FDG-PET-CT accuracy, PPV and NPV was 31.7, 12.0,96.7 and 78.9, 27.8,95.0%, respectively.

Conclusion

A negative [18F]FDG-PET-CT did not improve the exclusion of persistent vital tumor in the neck after primary RCT in comparison with contrast-CT alone. However, a positive [18F]FDG-PET-CT was a considerably better indicator of persistent, vital tumor in the neck than contrast-CT. If, based on the [18F]FDG-PET-CT result, the ND in patients with an uncertain or positive neck response in contrast CT had been omitted, the treatment of persistent nodal disease would have been delayed in 3 of 13 patients. On the other hand, if ND would have only been performed in [18F]FDG-PET-CT positive patients, an unnecessary ND would have been avoided in 11 of 20 patients.

Improving post-CRT neck assessment in patients with HPV-associated OPSCC (Review)

The positive predictive value (PPV) of 12-week post-therapy FDG-PET/CT is low in patients with Human Papillomavirus (HPV)-associated Oropharyngeal Squamous Cell Carcinoma (OPSCC) after treatment with definitive chemoradiation (CRT). Moreover, the diagnostic performance of post-CRT fine needle aspiration (FNA) in detecting persistent disease is unknown in this population. Given these important shortcomings in post-CRT treatment assessment, head and neck oncologists are limited in appropriately selecting patients for consolidative neck dissection, which results in over-treatment of a favorable risk population. Using the PubMed database, we performed a literature review of published series in HPV-associated OPSCC to investigate potential strategies for improvement of post-CRT neck assessment. Several different approaches were found, including continued surveillance with PET/CT, delayed timing of restaging PET/CT, initial response evaluation with multimodality or alternative imaging, and detection of circulating HPV DNA. At present, the optimal approach to post-CRT treatment assessment is unclear; further investigation and incorporation of new technologies and surveillance protocols will be highly beneficial for patients with HPV-associated OPSCC.

Follow up imaging of oral, oropharyngeal and hypopharyngeal cancer patients: Comparison of PET-CT and MRI post treatment

There is currently no consensus as to the ideal timing, frequency and modality of imaging for follow up of head and neck cancer patients. The aim of this study was to analyze the diagnostic accuracy of PET-CT versus MRI, and imaging at 3 versus 6 months for follow up of head and neck cancer patients treated with curative intent with no clinical signs of treatment failure.

MATERIALS AND METHODS

A retrospective study was performed for all head and neck cancers treated with curative intent at the Royal Derby Hospital. Data collected included demographic information, site of primary cancer, staging, treatment provided, type of follow up imaging performed and results of follow up imaging. Inclusion in the study was for oral, oropharyngeal and hypopharyngeal cancers treated with curative intent, asymptomatic patients, those who have had follow up imaging within 6 months of treatment, and those followed up for at least 2.5 years since treatment.

RESULTS

A total of 140 patients were included in the study. 25% of patients had evidence of recurrent/metastatic disease on imaging, 60% of which were identified within 6 months post treatment. The majority (60%) of failures were due to distant metastases. The sensitivity and specificity of both MRI and PET-CT was higher at 6 months post-treatment compared to 3 months post-treatment. Overall the sensitivity and specificity for PET-CT and MRI within 3-6 months post treatment were 94.7% and 83.5% and 60% and 85.7% respectively for identifying treatment failure.

CONCLUSION

Follow up Imaging at 6 months post treatment is more likely to accurately identify treatment failures with fewer false positives than imaging at 3 months. PET-CT is preferable to MRI for identifying post treatment locoregional and distant treatment failure.

Assessing Novel Drugs and Radiation Technology in the Chemoradiation of Oropharyngeal Cancer

Integrating immunotherapy, proton therapy and biological dose escalation into the definitive chemoradiation of oropharyngeal cancer poses several challenges. Reliable and reproducible data must be obtained in a timely fashion. However, despite recent international radiotherapy contouring guidelines, controversy persists as to the applicability of such guidelines to all cases. Similarly, a lack of consensus exists concerning both the definition of the organ at risk for oral mucositis and the most appropriate endpoint to measure for this critical toxicity. Finally, the correlation between early markers of efficacy such as complete response on PET CT following treatment and subsequent survival needs elucidation for biological subsets of oropharyngeal cancer.

Post-treatment 18F-FDG-PET/CT versus contrast-enhanced CT in patients with oropharyngeal squamous cell carcinoma: comparative effectiveness study

OBJECTIVE

To compare the accuracy of same-day therapy-assessment PET/computed tomography (PET/CT) and conventional contrast-enhanced computed tomography (CECT) in patients with oropharyngeal squamous cell carcinoma (OPSCC).

METHODS

A total of 110 (95 men and 15 women; mean age 59 years) patients with biopsy-proven OPSCC were evaluated with same-day PET/CT and CECT pair scans as part of follow-up therapy assessment. Scans were performed within 6 months after the completion of primary treatment (median time: 3.1 months; range: 0.5-6 months). PET/CT and CECT scans were reviewed retrospectively for residual primary site disease, and right and left cervical lymph node involvement. Histopathology or 6 month clinical/imaging follow-up were used as the gold standard. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated for the primary site and cervical nodal disease.

RESULTS

Of 110 OPSCC patients, 90.9% were human papilloma virus positive, 80.8% were stage 4, and 76.4% received chemoradiation as the primary treatment. The sensitivity, specificity, PPV, NPV, and accuracy of PET/CT and CECT were similar in the evaluation of the primary cancer site (PET/CT: 75.0, 91.5, 25.0, 99.0, and 90.9, respectively, versus CECT: 75.0, 90.6, 23.1, 99.0, and 90.0, respectively). In evaluating cervical lymph node involvement, PET/CT appeared to have higher accuracy (96.8 vs. 81.7%), specificity (97.7 vs. 81.7%), and PPV (45.8 vs. 16.5%), comparable NPV (99.4% for both), and lower sensitivity (65 vs. 75%) compared with same-day CECT.

CONCLUSION

Same-day PET/CT and CECT scans had comparable accuracy in the evaluation of primary tumor sites after completion of therapy in patients with OPSCC. PET/CT showed higher accuracy in the evaluation of cervical lymph node involvement.