Impact of positron emission tomography/computed tomography surveillance at 12 and 24 months for detecting head and neck cancer recurrence

De-escalation of post-treatment surveillance in oropharyngeal cancer

BACKGROUND

The majority of new oropharyngeal squamous cell carcinoma (OPSCC) cases are associated with human papillomavirus and favorable prognosis. Post-treatment follow-up should be targeted to patients at greatest risk for disease recurrence.

METHODS

To assess the benefits of routine clinical surveillance in OPSCC, we reviewed all follow-up visits conducted in 2014 at Helsinki University Hospital Department of Otorhinolaryngology.

RESULTS

Of 366 visits, 26 (7%) were from patients presenting with a new symptom, and disease recurrence was detected in four. The presence of a new symptom was significantly associated with disease recurrence (P < 0.001). Of 366 visits, 340 (93%) were from patients presenting without new symptoms, and not a single recurrence was found during these visits.

CONCLUSIONS

Based on our findings, and previous studies assessing the prognosis and pattern of recurrent OPSCC, we concluded that the number of routine post-treatment visits can be reduced. Follow-up should rather focus on symptom-directed examinations.

Posttreatment surveillance PET/CT for HPV-associated oropharyngeal cancer

BACKGROUND

Surveillance positron emission tomography-computed tomography (PET/CT) is commonly used for treatment assessment of radiation therapy in head and neck cancer. However, human papillomavirus-associated oropharyngeal squamous cell carcinoma (HPV+OPSCC) patients represent a unique subpopulation, for which the utility of surveillance PET/CT has not been well studied.

METHODS

In this retrospective chart review comprising 233 HPV+OPSCC patients, we evaluated surveillance PET/CT for diagnostic accuracy, downstream clinical impact, and survival.

RESULTS

Surveillance PET/CT demonstrated 100% negative predictive value and sensitivity, 59.9% specificity, and 13.4% positive predictive value. Surveillance PET/CT led to 90 imaging studies and 31 biopsies; 91.1% and 77.4% were negative for recurrence, respectively. Surveillance PET/CT led to meaningful salvage therapy in 1.6% of cases. PET/CT-detected recurrences did not have improved survival compared to clinically detected recurrences.

CONCLUSION

For HPV+OPSCC patients, surveillance PET/CTs frequently lead to unnecessary testing and rarely to meaningful disease salvage. They have no demonstrated survival benefit and should be interpreted cautiously to prevent patient harm.

Routine surveillance scanning in HNSCC: Lung screening CT scans have value but head and neck scans do not

OBJECTIVES

To examine the utility of computed tomography (CT) imaging during routine surveillance for the detection of recurrent head and neck squamous cell carcinoma (HNSCC).

MATERIALS/METHODS

Clinical characteristics of HNSCC patients treated between 2008 and 2017 with radiation therapy or concurrent chemoradiation were abstracted from medical records. In patients who achieved a complete response to treatment by positron emission tomography scan, surveillance CT scans were conducted to the maxillofacial area, neck, and chest every 3 months in year 1, every 6 months in year 2, and every 12 months in years 3 and beyond.

RESULTS

Within the entire cohort (n = 534), complete response was achieved in 446 patients (83.5%); of these, 84 (15.7%) patients had a recurrence. Among the 84 patients with disease recurrence, 25 (30%) patients remained alive, of which 15 (18%) underwent successful salvage treatment and became free of disease. Lung screening CT scans detected failure in 8 of these successfully salvaged patients. Among the 8 patients successfully salvaged for locoregional recurrence, 3 failures were asymptomatic at onset and detected by laryngoscope or dental exam. The remaining 5 failures were symptomatic and detected upon work up prompted by symptoms. Maxillofacial and neck surveillance CT imaging failed to detect any successfully salvaged patients.

CONCLUSIONS

Routine surveillance for HNSCC patients with lung CT imaging had value but routine head and neck CT scans failed to identify any successfully salvaged patients. Given this finding, routine CT imaging surveillance in HNSCC patients should be restricted to annual lung screening with low-dose chest CT.

Negative Predictive Value of NI-RADS Category 2 in the First Posttreatment FDG-PET/CT in Head and Neck Squamous Cell Carcinoma

BACKGROUND AND PURPOSE

FDG PET/CT has a high negative predictive value in patients with head and neck squamous cell carcinoma who responds completely to non-operative therapy. However, the treatment failure rate in patients with a partial but incomplete response is unclear. Our aim was to investigate the negative predictive value of the first posttreatment FDG-PET/CT in patients with head and neck squamous cell carcinoma with incomplete response interpreted as Neck Imaging Reporting and Data System (NI-RADS) category 2.

MATERIALS AND METHODS

We retrospectively identified patients with head and neck squamous cell carcinoma treated with chemoradiation or radiation therapy with curative intent in our institution between 2008 and 2016. We included patients whose first posttreatment FDG-PET/CT was interpreted as showing marked improvement of disease but who had a mild residual mass or FDG avidity in either the primary tumor bed or lymph nodes (NI-RADS 2). The negative predictive value of FDG-PET/CT was calculated, including the 95% CI, using the Newcombe method. Two-year disease-free survival was the reference standard.

RESULTS

Seventeen of 110 patients (15%) experienced locoregional treatment failure within 2 years of completing treatment, yielding a negative predictive value of 85% (95% Cl, 77%-90%). The most common location of tumor recurrence was the cervical lymph nodes (59%). The median time interval between completion of therapy and treatment failure was 10 months (range, 5-24 months).

CONCLUSIONS

In patients with an incomplete response after treatment of head and neck squamous cell carcinoma, the negative predictive value of the first posttreatment FDG-PET/CT was 85%, which is lower than the 91% negative predictive value of FDG-PET/CT in patients with an initial complete response. Patients with an incomplete response (NI-RADS 2) should undergo more frequent clinical and imaging surveillance than patients with an initial complete response (NI-RADS 1).

Surgical Perspectives in Head and Neck Cancer

Head and neck cancer treatment is a complex multidisciplinary undertaking. Cancer cure and survival is a primary goal, yet safe-guarding appearance and function to preserve the quality of life are similarly critical. The head and neck surgeon remains central to multidisciplinary cancer care, with deep knowledge of operative technique and an even deeper understanding of cancer biology. The surgeon models practice based on the highest levels of scientific evidence, but also takes into consideration the approaches that may best suit an individual patient. The surgeon's role moreover spans the life history of a head and neck cancer patient, from diagnosis to surveillance. The intimacy of this role makes the surgeon a trusted and frequent frame of reference for the patient. In this chapter, we provide an overview of the surgeon's role in head and neck cancer management. We discuss surgical perspectives within the multidisciplinary care team and selectively highlight some of the more provocative clinical scenarios in the field.

AHNS Series: Do you know your guidelines? Evidence-based management of oral cavity cancers

Oral cavity squamous cell carcinoma (OCSCC) is the most common nonmelanoma head and neck cancer in the world, with an estimated 405 000 new cases expected each year. Subsites of the oral cavity include the alveolar ridge, buccal mucosa, anterior tongue, tonsillar pillar, retromolar trigone, hard palate, gingiva, and floor of the mouth. In this issue of the AHNS "Do you know your guidelines?" series, we review the evidence-based approach to the management of oral cavity carcinomas based on the framework provided by the National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines in Oncology.

18FDG PET/CT in Routine Surveillance of Asymptomatic Patients following Treatment of Sinonasal Neoplasms

Objective Sinonasal neoplasms have a high rate of recurrence following treatment, and current guidelines support the use of a variety of surveillance techniques. Recent work demonstrates that performance parameters of surveillance modalities may differ with sinonasal tumors in particular when compared with head and neck tumors overall. This study aims to characterize the value of ¹⁸fluorodeoxyglucose (¹⁸FDG) positron emission tomography/computed tomography (PET/CT) as a screening tool in asymptomatic patients. Study Design Retrospective cohort study. Setting Hospital of the University of Pennsylvania and Pennsylvania hospital. Methods Records of asymptomatic patients without suspicious endoscopy or suspicious imaging other than PET during the first 3 years following definitive treatment for sinonasal malignancy were screened and analyzed for inclusion in the cohort. Disease recurrence was determined by biopsy following suspicious PET evaluation. Results PET/CT scans (n = 111) were performed for 45 disease-free asymptomatic patients with no evidence of disease on endoscopy, and 6.3% were suspicious and prompted biopsy during this period, revealing 3 cases of disease recurrence. Overall specificity for PET/CT alone was 96.3% (95% CI, 90.7%-99.0%), with a negative predictive value of 99% (95% CI, 94.8%-100%). All recurrences were detected between 7 and 12 months, and all patients with true recurrence diagnosed by PET/CT had extrasinonasal involvement of tumor at the time of surgery. Conclusion We examined performance parameters of ¹⁸FDG PET/CT in asymptomatic patients with no evidence of disease on endoscopy during the posttreatment period for sinonasal malignancy. The ability of PET/CT to detect recurrences that may be missed by structural imaging or endoscopy makes it a valuable tool for clinicians.

Clinical Practice in PET/CT for the Management of Head and Neck Squamous Cell Cancer

OBJECTIVE

The purpose of this article is to summarize the evidence for the value of PET/CT for the management of patients with head and neck squamous cell cancer and suggest best clinical practices.

CONCLUSION

FDG PET/CT is a valuable imaging tool for identifying unknown primary tumors in patients with known cervical node metastases leading to management change and is the standard of care for the initial staging of stage III and IV head and neck squamous cell carcinomas (HNSCCs), for assessing therapy response when performed at least 12 weeks after chemoradiation therapy, and for avoiding unnecessary planned neck dissection. Neck dissection is avoided if PET/CT findings are negative-regardless of the size of the residual neck nodes-because survival outcomes are not compromised. FDG PET/CT is valuable in detecting recurrences and metastases during follow-up when suspected because of clinical symptoms and serves as a prognostic marker for patient survival outcomes, for 5 years. Using FDG PET/CT for routine surveillance of HNSCC after 6 months of treatment without any clinical suspicion should be discouraged.

Initial Performance of NI-RADS to Predict Residual or Recurrent Head and Neck Squamous Cell Carcinoma

BACKGROUND AND PURPOSE

The Head and Neck Imaging Reporting and Data System (NI-RADS) surveillance template for head and neck cancer includes a numeric assessment of suspicion for recurrence (1-4) for the primary site and neck. Category 1 indicates no evidence of recurrence; category 2, low suspicion of recurrence; category 3, high suspicion of recurrence; and category 4, known recurrence. Our purpose was to evaluate the performance of the NI-RADS scoring system to predict local and regional disease recurrence or persistence.

MATERIALS AND METHODS

This study was classified as a quality-improvement project by the institutional review board. A retrospective database search yielded 500 consecutive cases interpreted using the NI-RADS template. Cases without a numeric score, non-squamous cell carcinoma primary tumors, and primary squamous cell carcinoma outside the head and neck were excluded. The electronic medical record was reviewed to determine the subsequent management, pathology results, and outcome of clinical and radiologic follow-up.

RESULTS

A total of 318 scans and 618 targets (314 primary targets and 304 nodal targets) met the inclusion criteria. Among the 618 targets, 85.4% were scored NI-RADS 1; 9.4% were scored NI-RADS 2; and 5.2% were scored NI-RADS 3. The rates of positive disease were 3.79%, 17.2%, and 59.4% for each NI-RADS category, respectively. Univariate association analysis demonstrated a strong association between the NI-RADS score and ultimate disease recurrence, with P < .001 for primary and regional sites.

CONCLUSIONS

The baseline performance of NI-RADS was good, demonstrating significant discrimination among the categories 1-3 for predicting disease.

(18)F-FDG PET/CT to assess response and guide risk-stratified follow-up after chemoradiotherapy for oropharyngeal squamous cell carcinoma

PURPOSE

To evaluate the use of (18)F-FDG PET/CT as the principal investigation to assess tumour response, to determine the need for further surgery and to guide follow-up following radical chemoradiotherapy for stage III/IV oropharyngeal squamous cell carcinoma (OPSCC).

METHODS

A retrospective analysis was undertaken in 146 patients treated at our centre with radical chemoradiotherapy for OPSCC and who had a PET/CT scan to assess response. According to the PET/CT findings, patients were divided into four groups and recommendations: (1) complete metabolic response (enter clinical follow-up); (2) low-level uptake only (follow-up PET/CT scan in 12 weeks); (3) residual uptake suspicious for residual disease (further investigation with or without neck dissection); and (4) new diagnosis of distant metastatic disease (palliative treatment options).

RESULTS

The initial PET/CT scan was performed at a median of 12.4 weeks (range 4.3 - 21.7 weeks) following treatment. Overall sensitivity and specificity rates were 92.0 % (74.0 - 99.0 %) and 85 % (77.5 - 90.9 %). Of the 146 patients, 90 (62 %) had a complete response and had estimated 3-year overall and disease-free survival rates of 91.9 % (85.6 - 98.2 %) and 85.6 % (78.0 - 93.2 %), respectively, 17 (12 %) had residual low-level uptake only (with two having confirmed residual disease on subsequent PET/CT, both surgically salvaged), 30 (21 %) had suspicious residual uptake (12 proceeded to neck dissection; true positive rate at surgery 33 %). HPV-positive patients with reassuring PET/CT findings had an estimated 3-year progression-free survival rate of 91.7 % (85.2 - 98.2 %), compared with 66.2 % (41.5 - 90.9 %) of HPV-negative patients.

CONCLUSION

A strategy of using PET/CT results alongside clinical examination to help select patients for salvage surgery appears successful. Despite a complete response on the 12-week PET/CT scan, HPV-negative patients have a significant risk of disease relapse in the following 2 years and further studies to assess whether surveillance imaging in this group could improve outcomes are warranted.

Follow-up in Head and Neck Cancer: Do More Does It Mean Do Better? A Systematic Review and Our Proposal Based on Our Experience

As the patients population ages, cancer screening increases, and cancer treatments improve, millions more head and neck carcinoma (HNC) patients will be classified as cancer survivors in the future. Change in epidemiology with human papillomavirus related HNC leads to a number of young treated patients. After treatment for HNC intensive surveillance, including ear, nose and throat (ENT) endoscopy, imaging, and serology, confers a survival benefit that became less evident in unresectable recurrence. We performed a comprehensive revision of literature and analyzed the experience of our centre. We revised publications on this topic and added data derived from the interdisciplinary work of experts within medical oncology, ENT, and radiation oncology scientific societies. We retrospectively collected local and distant recurrence of chemoradiation treated patients at Santa Croce and Carle University Hospital. A HNC follow-up program is not already codified and worldwide accepted. There is a need of scheduled follow-up. We suggest adopting a standardized follow-up guideline, although a multidisciplinary approach is frequently requested to tailor surveillance program and treatment on each patient.

Positron-emission tomography/computed tomography imaging in head and neck oncology: An update

Cancers of the head and neck account for more than half a million cases worldwide annually, with a significant majority diagnosed as squamous cell carcinoma (HNSCC). Imaging studies such as contrast-enhanced computed tomography (CT), magnetic resonance imaging (MRI) and ¹⁸F-2-fluoro-2-deoxy-D-glucose positron-emission tomography/computed tomography (¹⁸F-FDG PET/CT) are widely used to determine the presence and extent of tumors and metastatic disease, both before and after treatment. Advances in PET/CT imaging have allowed it to emerge as a superior imaging modality compared to both CT and MRI, especially in detection of carcinoma of unknown primary, cervical lymph node metastasis, distant metastasis, residual/recurrent cancer and second primary tumors, often leading to alteration in management. PET/CT biomarker may further provide an overall assessment of tumor aggressiveness with prognostic implications. As new developments emerged leading to better understanding and use of PET/CT in head and neck oncology, the aim of this article is to review the roles of PET/CT in both pre- and post-treatment management of HNSCC and PET-derived parameters as prognostic indicators.

Oral cavity and oropharyngeal squamous cell carcinoma--an update

Oral cavity squamous cell carcinoma (OC-SCC) is the most common malignancy of the head and neck (excluding nonmelanoma skin cancer). Recent trends have shown a dramatic rise in the incidence of oropharyngeal squamous cell carcinoma (OP-SCC), with a marked increase in lesions related to human papillomavirus infection. This update presents the latest evidence regarding OC-SCC and OP-SCC. In particular, the authors compare and contrast tumors at these two sites with respect to epidemiology, etiopathogenesis, clinicopathologic presentation, clinical assessment, imaging, management, and prognosis. It is important for clinicians to be aware of differences between OC-SCC and OP-SCC so that appropriate patient education and multidisciplinary care can be provided to optimize outcomes.

FDG-PET/contrast-enhanced CT as a post-treatment tool in head and neck squamous cell carcinoma: comparison with FDG-PET/non-contrast-enhanced CT and contrast-enhanced CT

OBJECTIVE

To evaluate the accuracy of PET/CT using (18)F-fluorodeoxyglucose (FDG) with IV contrast for suspected recurrent head and neck squamous cell carcinoma (HNSCC).

METHODS

One hundred and seventy patients previously treated for HNSCC underwent PET/CT, consisting of non-contrast-enhanced and contrast-enhanced CT, to investigate suspected recurrence. Diagnostic performance of PET/contrast-enhanced CT (PET/ceCT), PET/non-contrast-enhanced CT (PET/ncCT) and contrast-enhanced CT (ceCT) for local or regional recurrence, distant metastasis, overall recurrence and second primary cancer was evaluated. The reference standard included histopathology, treatment change and imaging follow-up.

RESULTS

The patient-based areas under the receiver operating characteristic curves (AUC) for ceCT, PET/ncCT and PET/ceCT were 0.82, 0.96 and 0.98 for local recurrence, 0.73, 0.86 and 0.86 for regional recurrence, 0.86, 0.91 and 0.92 for distant metastasis, 0.72, 0.86 and 0.87 for overall recurrence, and 0.86, 0.89 and 0.91 for a second primary cancer. Both PET/ceCT and PET/ncCT statistically showed larger AUC than ceCT for recurrence, and the difference between PET/ceCT and PET/ncCT for local recurrence reached a significant level (p = 0.039). The accuracy of PET/ceCT for diagnosing overall recurrence was high, irrespective of the time interval after the last treatment (83.3-94.1 %).

CONCLUSION

FDG-PET/CT was a more accurate HNSCC restaging tool than ceCT. The added value of ceCT at FDG-PET/CT is minimal.

KEY POINTS

• FDG-PET/CT is a more accurate post-treatment surveillance tool than ceCT for HNSCC. • FDG-PET/ceCT was useful, irrespective of the time interval after the last treatment. • FDG-PET/ceCT showed high negative predictive value and limited positive predictive value. • The added value of ceCT at FDG-PET/CT is minimal and likely not clinically relevant.

Optimal timing of first posttreatment FDG PET/CT in head and neck squamous cell carcinoma

BACKGROUND

The optimal timing for the initial posttreatment fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT scan after definitive treatment of head and neck squamous cell carcinoma (HNSCC) is unclear.

METHODS

We conducted a retrospective review of 247 patients with definitively treated nonmetastatic HNSCC. First posttreatment PET/CT scans were grouped into: <7 weeks, 7 to 10 weeks, 11 to 14 weeks, and ≥15 weeks. Scans were categorized as positive or negative and accuracy of scans was calculated for each group using biopsy, subsequent imaging, or clinical follow-up for 1 year after treatment as a reference standard.

RESULTS

Sixty-seven of the 247 patients (27.1%) had treatment failure. Scans performed at <7 weeks were less accurate than all other time intervals (p < .05). Scans performed at all other intervals were similar in accuracy.

CONCLUSION

First posttreatment PET/CT can be obtained as early as 2 months after therapy. Scans performed earlier than 2 months have lower accuracy. © 2015 Wiley Periodicals, Inc. Head Neck 38: E853-E858, 2016.

Evaluation of spheroid head and neck squamous cell carcinoma cell models in comparison to monolayer cultures

Two-dimensional (2D) monolayer cell culture models are the most common method used to investigate tumor cells in vitro. In the few last decades, a multicellular spheroid model has gained attention due to its adjacency to tumors in vivo. The aim of the present study was to investigate immunohistochemical differences between these two cell culture systems. The FaDu, CAL27 and SCC25 head and neck squamous cell carcinoma (HNSCC) cell lines were seeded out in monolayer and multicellular spheroids. The FaDu and SCC25 cells were treated with increasing doses of cisplatin and irradiation. CAL27 cells were not used in theproliferation experiments, since the spheroids of CAL27 cells were not able to process the reagent in CCK-8 assays. Furthermore, they were stained to present alterations of the following antigens: Ki-67, vascular endothelial growth factor receptor, epithelial growth factor and survivin. Differences in growth rates and expression patterns were detected in certain HNSCC cell lines. The proliferation rates showed a significant divergence of cells grown in the three-dimensional model compared with cells grown in the 2D model. Overall, multicellular spheroids are a promising method to reproduce the immunohistochemical aspects and characteristics of tumor cells, and may show different response rates to therapeutic options.

The Limitations of Routine Magnetic Resonance Imaging for Long-Term Post-Treatment Locoregional Surveillance of Salivary Carcinoma

BACKGROUND/AIMS

To determine the utility of head and neck magnetic resonance imaging (HN-MRI) for the routine surveillance of patients without concurrent symptoms or signs of recurrence more than 6 months after treatment for salivary gland carcinoma (SGC).

METHODS

This is a retrospective single-institution review of SGC patients from 2000 to 2011 who underwent one or more HN-MRI scans without concurrent suspicious symptoms or signs of recurrence more than 6 months after the completion of treatment, with at least 6 months of follow-up after each scan.

RESULTS

Out of an original 283 SGC patients treated surgically, 41 patients, who were disease free 6 months after treatment, had undergone 96 routine HN-MRIs without concurrent suspicious symptoms or signs. Ten out of the 41 patients (24%) experienced a false-positive finding with routine HN-MRI. None of the 96 HN-MRIs demonstrated a true-positive or false-negative finding.

CONCLUSION

More than 6 months after treatment, routine HN-MRI for the detection of locoregional recurrence of SGC has a low utility in patients without concurrent suspicious symptoms or signs. While these data support the judicious use of routine HN-MRIs, the managing physician should ultimately decide on the best course of surveillance for an individual patient based on the unique risk factors and circumstances present.

The advantages and drawbacks of routine magnetic resonance imaging for long-term post-treatment locoregional surveillance of oral cavity squamous cell carcinoma

PURPOSE

Assess the clinical utility and accuracy of routine surveillance head and neck magnetic resonance imaging (HN-MRI) for the detection of locoregional recurrence in patients with a history of oral cavity squamous cell carcinoma (OCSCC) without concurrent suspicious symptoms or signs 6 months or more after treatment.

MATERIALS AND METHODS

For OCSCC patients who underwent routine (defined as: without concurrent suspicious symptoms or signs) surveillance HN-MRI at 6 months or more after treatment completion, we retrospectively determined the detection rate of locoregional disease and false positive rate.

RESULTS

Out of an original cohort of 533 OCSCC patients, 46 patients, who were disease-free 6 months after treatment, had undergone 108 routine HN-MRIs from 6 to 48 months after surgery without the presence of concurrent suspicious symptoms or signs and had 6 months of subsequent follow up. 1 out of 46 (2.2%) had a true positive regional recurrence. 10 out of 46 (21.7%) patients experienced a false positive locoregional finding.

CONCLUSIONS

Routine HN-MRI for locoregional surveillance of OCSCC, when used in patients without concurrent suspicious symptoms or exam findings over 6 months since treatment, may be unnecessary and costly given the very low rate of recurrence and high false positive rate. Our study supports the National Comprehensive Cancer Network guideline of limiting imaging after 6 months of primary treatment completion to patients with suspicious clinical findings. Nonetheless, managing physicians should continue to be empowered to use surveillance imaging based on risk profiles and unique circumstances for each patient.

Surveillance radiologic imaging after treatment of oropharyngeal cancer: a review

The increasing proportion of human papilloma virus-related oropharynx cancers has led to improved success in the treatment of this disease. However, the current low recurrence rate after treatment of oropharyngeal cancer highlights the continued need for, as well as the challenges of, designing an effective follow-up surveillance program. There are frequently multiple modalities used in the treatment of oropharyngeal cancer, resulting in short- and long-term tissue changes to the head and neck that challenge clinical distinction of recurrence versus treatment-related changes. The oropharynx subsite is characterized by complex anatomy not always accessible to physical exam, making radiologic imaging a potentially useful supplement for effective follow-up assessment. In this manuscript, the literature regarding the type of radiologic imaging modality and the frequency of obtaining imaging studies in the surveillance follow-up after treatment of oropharyngeal cancer is reviewed. While ultrasound and MRI have useful characteristics that deserve further study, PET/CT appears to have the best sensitivity and specificity for imaging surveillance follow-up of head and neck cancers including oropharyngeal cancer. A negative PET/CT is particularly useful as a predictor of prognosis and can guide the clinician as to when to stop obtaining additional imaging studies in the absence of clinical signs of recurrence. However, there is scant evidence that imaging surveillance can improve survival outcomes. Suggestions to guide future imaging surveillance research studies are provided.

Role of 18F-FDG PET/CT in pre and post treatment evaluation in head and neck carcinoma

Head and neck cancer (HNC) ranks as the 6^th most common cancer worldwide, with the vast majority being head and neck squamous cell carcinoma (HNSCC). The majority of patients present with complicated locally advanced disease (typically stage III and IV) requiring multidisciplinary treatment plans with combinations of surgery, radiation therapy and chemotherapy. Tumor staging is critical to decide therapeutic planning. Multiple challenges include accurate tumor localization with precise delineation of tumor volume, cervical lymph node staging, detection of distant metastasis as well as ruling out synchronous second primary tumors. Some patients present with cervical lymph node metastasis without obvious primary tumors on clinical examination or conventional cross sectional imaging. Treatment planning includes surgery, radiation, chemotherapy or combinations that could significantly alter the anatomy and physiology of this complex head and neck region, making assessment of treatment response and detection of residual/ recurrent tumor very difficult by clinical evaluation and computed tomography (CT) or magnetic resonance imaging (MRI). ¹⁸F-2-fluoro-2-deoxy-D-glucose positron emission tomography/CT (¹⁸F-FDG PET/CT) has been widely used to assess HNC for more than a decade with high diagnostic accuracy especially in detection of initial distant metastasis and evaluation of treatment response. There are some limitations that are unique to PET/CT including artifacts, lower soft tissue contrast and resolution as compared to MRI, false positivity in post-treatment phase due to inflammation and granulation tissues, etc. The aim of this article is to review the roles of PET/CT in both pre and post treatment management of HNSCC including its limitations that radiologists must know. Accurate PET/CT interpretation is the crucial initial step that leads to appropriate tumor staging and treatment planning.

Predictive accuracy of first post-treatment PET/CT in HPV-related oropharyngeal squamous cell carcinoma

OBJECTIVES/HYPOTHESIS

To determine whether the result of first posttreatment positron emission tomography and computed tomography (PET/CT) is predictive of outcome in patients with oropharyngeal squamous cell carcinoma (OPSCC), and whether PET/CT accuracy is affected by human papillomavirus (HPV) status.

STUDY DESIGN

Retrospective review.

METHODS

Demographic, clinical, and radiographic data were available for 61 patients with OPSCC, treated in 2004 to 2012 at a single tertiary academic referral center, with at least one baseline and one posttreatment PET/CT. Clinical follow-up was obtained every 3 months thereafter. The median follow-up time was 36 months (range 3-100 months).

RESULTS

Of 61 patients, 48 (79%) had negative first posttreatment PET/CT results; and overall, 18 of the 61 patients (30%) recurred. All accuracy measures for PET/CT were higher in HPV-positive patients, including a 93% negative predictive value (NPV). Patients with positive PET/CT results had poorer survival on Kaplan-Meier analyses. On multivariate analysis of factors predictive of recurrence, two parameters were significant: HPV status (P = 0.0046) and PET/CT result (P <0.0001).

CONCLUSIONS

A negative first posttreatment PET/CT result is associated with better prognosis and rare recurrence, especially in patients with HPV-positive status. Less frequent radiologic surveillance is warranted in patients with HPV-positive OPSCC and a negative first posttreatment PET/CT scan.

Observation versus neck dissection for positron-emission tomography-negative lymphadenopathy after chemoradiotherapy

OBJECTIVES/HYPOTHESIS

To analyze outcomes among patients with residual positron-emission tomography (PET)-negative lymphadenopathy after chemoradiotherapy for head and neck cancer based on whether or not they underwent neck dissection.

STUDY DESIGN

Retrospective review.

METHODS

Fifty-five patients with stage III/IV squamous cell carcinoma of the head and neck were identified with residual PET-negative lymphadenopathy based on standardized uptake value of <3. All patients had been treated with chemoradiotherapy to a median dose of 70 Gy (range, 60-4 Gy).

RESULTS

With a median follow-up of 30 months (range, 6-67 months), the 3-year overall survival (85% vs. 81%, P = .57), progression-free survival (88% vs. 88%, P = .42), and local-regional control (96% vs. 100%, P = .68), did not differ between patients treated by neck dissection or observation.

CONCLUSIONS

Omission of neck dissection appears to be reasonable for patients with residual lymphadenopathy but negative PET after chemoradiotherapy for head and neck cancer.

LEVEL OF EVIDENCE

4.

(18)F-FDG PET/CT surveillance at 3-6 and 12 months for detection of recurrence and second primary cancer in patients with head and neck squamous cell carcinoma

Background:

Early detection of recurrence of head and neck squamous cell carcinoma (HNSCC), which is often obscured by surgical or radiotherapy-induced tissue distortion, is essential for proper patient management.

Methods:

A total of 143 consecutive patients with previously untreated HNSCC were evaluated by whole-body fluorine 18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) and regular clinical follow-up after curative treatment. The ¹⁸F-FDG PET/CT was performed ∼3–6 and 12 months after treatment and findings suspicious for recurrence or SPC were confirmed using histopathology.

Results:

The sensitivities of 3–6- and 12-month PET/CT scans at patient level were 96% and 93%, respectively, and those of regular clinical follow-up were 11% and 19%, respectively (McNemar test, P<0.001). In patients with no clinical suspicion, PET/CT detected 95% and 91% of recurrent patients at 3–6 and 12 months, respectively. The sensitivity of PET/CT for the identification of SPC was 29% and 80% at 3–6 and 12 months, respectively. A positive interpretation of PET/CT was significantly associated with poor overall survival (log-rank test, P<0.001).

Conclusion:

The ¹⁸F-FDG PET/CT surveillance is beneficial for the detection of recurrence that may be missed by regular follow-up physical and endoscopic examinations of the head and neck area after curative treatment for HNSCC.

Early detection of recurrent disease by FDG-PET/CT leads to management changes in patients with squamous cell cancer of the head and neck

OBJECTIVE

The objective of this study was to compare the efficacy of surveillance high-resolution computed tomography (HRCT) and physical examination/endoscopy (PE/E) with the efficacy of fluorodeoxyglucose (FDG)-positron emission tomography (PET)/HRCT for the detection of relapse in head and neck squamous cell carcinoma (HNSCC) after primary treatment.

METHODS

This is a retrospective analysis of contemporaneously performed FDG-PET/HRCT, neck HRCT, and PE/E in 99 curatively treated patients with HNSCC during post-therapy surveillance to compare performance test characteristics in the detection of early recurrence or second primary cancer.

RESULTS

Relapse occurred in 19 of 99 patients (20%) during a median follow-up of 21 months (range: 9-52 months). Median time to first PET/HRCT was 3.5 months. The median time to radiological recurrence was 6 months (range: 2.3-32 months). FDG-PET/HRCT detected more disease recurrences or second primary cancers and did so earlier than HRCT or PE/E. The sensitivity, specificity, and positive and negative predictive values for detecting locoregional and distant recurrence or second primary cancer were 100%, 87.3%, 56.5%, and 100%, respectively, for PET/HRCT versus 61.5%, 94.9%, 66.7%, and 93.8%, respectively, for HRCT versus 23.1%, 98.7%, 75%, and 88.6%, respectively, for PE/E. In 19 patients with true positive PET/HRCT findings, a significant change in the management of disease occurred, prompting either salvage or systemic therapy. Of the 14 curatively treated patients, 11 were alive with without disease at a median follow-up of 31.5 months.

CONCLUSION

FDG-PET/HRCT has a high sensitivity in the early detection of relapse or second primary cancer in patients with HNSCC, with significant management implications. Given improvements in therapy and changes in HNSCC biology, appropriate modifications in current post-therapy surveillance may be required to determine effective salvage or definitive therapies.