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

Posttreatment Head and Neck Cancer Imaging: Anatomic Considerations Based on Cancer Subsites

Posttreatment imaging surveillance of head and neck cancer is challenging owing to complex anatomic subsites and diverse treatment modalities. Early detection of residual disease or recurrence through surveillance imaging is crucial for devising optimal treatment strategies. Posttreatment imaging surveillance is performed using CT, fluorine 18-fluorodeoxyglucose PET/CT, and MRI. Radiologists should be familiar with postoperative imaging findings that can vary depending on surgical procedures and reconstruction methods that are used, which is dictated by the primary subsite and extent of the tumor. Morphologic changes in normal structures or denervation of muscles within the musculocutaneous flap may mimic recurrent tumors. Recurrence is more likely to occur at the resection margin, margin of the reconstructed flap, and deep sites that are difficult to access surgically. Radiation therapy also has a varying dose distribution depending on the primary site, resulting in various posttreatment changes. Normal tissues are affected by radiation, with edema and inflammation occurring in the early stages and fibrosis in the late stages. Distinguishing scar tissue from residual tumor becomes necessary, as radiation therapy may leave behind residual scar tissue. Local recurrence should be carefully evaluated within areas where these postradiation changes occur. Head and Neck Imaging Reporting and Data System (NI-RADS) is a standardized reporting and risk classification system with guidance for subsequent management. Familiarity with NI-RADS has implications for establishing surveillance protocols, interpreting posttreatment images, and management decisions. Knowledge of posttreatment imaging characteristics of each subsite of head and neck cancers and the areas prone to recurrence empowers radiologists to detect recurrences at early stages. ©RSNA, 2024 Test Your Knowledge questions in the supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Current status of sinonasal cancer survivorship care

Sinonasal cancer is a heterogeneous orphan disease of diverse histologies, each with distinct clinical, oncologic, and toxicity profiles. Because of the comparative rarity of these cancers, sinonasal cancers are treated as a grouped diagnosis despite their clinical and biological heterogeneity. Multimodality treatment with a combination of surgery, chemotherapy, and/or radiotherapy is the standard-of-care for advanced-stage patients but there are few surveillance or follow-up practice guidelines or formalized survivorship care pathways. A scoping literature review was conducted via PubMed, EMBASE, and Google Scholar. A total of 112 studies were included, which were grouped along the following topics: surveillance, second primary tumors, quality of life, and symptom burden. Sinonasal cancer tends to exhibit a higher rate of local failure and occur in a delayed fashion compared to mucosal malignancies of the head and neck. Moreover, the site of failure and time-varying risk of recurrence is histology-specific. Following multimodality treatment of the skull base, patients may experience endocrine, visual, auditory, sinonasal, olfactory, and neurocognitive deficits, as well as psychosocial impairments that impact multiple physical and neuropsychological domains, resulting in diminished quality of life. Sinonasal cancer patients would benefit from tailored, histology-specific survivorship programs to address the recurrence, second primary, and functional impairments resulting from disease and treatment toxicity.

The Role of Positron Emission Tomography for the Management of Sinonasal Malignancies: A Systematic Review

BACKGROUND

Positron emission tomography (PET) scan is a valuable imaging modality widely used in the management of cancers. Its usage is well defined for most head and neck malignancies. However, there is a lack of consensus regarding the utility of PET scan for sinonasal malignancies. This is highlighted by the latest international consensus statement on endoscopic skull base surgery.

OBJECTIVE

This systematic review aims to clarify the role of PET scan in the management of sinonasal malignancies.

METHODS

We conducted a comprehensive literature search using PubMed, MEDLINE, EMBASE, Web of Science, CINAHL, and Cochrane databases for research studies of interest. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) updated statement was used to guide the review.

RESULTS

In total, 1807 articles were assessed for eligibility. Thirty-nine original papers, published between 2004 and 2021, met inclusion criteria. Seven articles focused on the role of PET scan for inverted papilloma, 23 for sinonasal carcinoma, 4 for melanoma, and 3 for lymphoma, and finally, 3 articles focused on the use of specific PET scan tracers for sinonasal malignancies. Qualitative summaries for each potential role of PET scans were provided. In general, included studies were retrospective in nature with low level of evidence.

CONCLUSIONS

In general, and across all types of sinonasal malignancies, PET scan yielded positive results regarding detection and initial staging. It was also considered as the modality of choice for detection of distant metastases, except in the case of sinonasal lymphoma. PET scan's main limit resides in its inability to detect lesions in or close to the metabolic activity of the brain.

PET/CT Imaging in Treatment Planning and Surveillance of Sinonasal Neoplasms

Sinonasal cancers are uncommon malignancies with a generally unfavorable prognosis, often presenting at an advanced stage. Their high rate of recurrence supports close imaging surveillance and the utilization of functional imaging techniques. Whole-body 18F-FDG PET/CT has very high sensitivity for the diagnosis of sinonasal malignancies and can also be used as a "metabolic biopsy" in the characterization of some of the more common subgroups of these tumors, though due to overlap in uptake, histological confirmation is still needed. For certain tumor types, radiotracers, such as 11C-choline, and radiolabeled somatostatin analogs, including 68Ga-DOTATATE/DOTATOC, have proven useful in treatment planning and surveillance. Although serial scans for posttreatment surveillance allow the detection of subclinical lesions, the optimal schedule and efficacy in terms of survival are yet to be determined. Pitfalls of 18F-FDG, such as post-surgical and post-radiotherapy crusting and inflammation, may cause false-positive hypermetabolism in the absence of relapse.

Recurrence Patterns and Efficacy of Surveillance Modalities for Sinonasal Malignancies

OBJECTIVE

There is limited information regarding the recurrence patterns and efficacy of surveillance modalities in patients with sinonasal malignancies.

METHODS

A retrospective study was conducted between the years 2001-2018 at a tertiary care center. Included were all patients with sinonasal malignancies treated in our institution. Data regarding recurrence and survival were analyzed.

RESULTS

Eighty-one patients were included. Multimodal treatment was administered to the majority of patients. 24 (35.3%) patients recurred with a median time of 17 months (range, 4-180). Although the majority of recurrences occurred within the first 5 years (83.3%), 4 (16.6%) recurred later on (5-15 years). Recurrences were local in 83.3%, regional in 20.8% and distant in 16.6%. All local recurrences occurred within the radiation treatment field and all patients with distant failure had mucosal melanoma. The majority of recurrences (70.6%) were diagnosed clinically or endoscopically, mainly in patients with SCC during the first 2 years of follow up. MRI or PET-CT were crucial in detecting extra-sinus and distant failures. Salvage surgery was feasible in the majority of patients (58.3%). Overall, 5 years survival (OS) rate was 60.9%.

CONCLUSIONS

Frequent clinic visits with nasal endoscopy combined with frequent imaging studies should be routinely practiced as part of a long-term surveillance plan. Longer follow up duration should be considered in these patients.

Radiotherapy of sinonasal cancers

We present the update of the recommendations of the French society of radiotherapy and oncology on the indications and the technical methods of carrying out radiotherapy of sinonasal cancers. Sinonasal cancers (nasal fossae and sinus) account for 3 to 5% of all cancers of the head and neck. They include carcinomas, mucosal melanomas, sarcomas and lymphomas. The management of sinonasal cancers is multidisciplinary but less standardized than that of squamous cell carcinomas of the upper aerodigestive tract. As such, patients with sinonasal tumors can benefit from the expertise of the French expertise network for rare ENT cancers (Refcor). Knowledge of sinonasal tumour characteristics (histology, grade, risk of lymph node involvement, molecular characterization, type of surgery) is critical to the determination of target volumes. An update of multidisciplinary indications and recommendations for radiotherapy in terms of techniques, target volumes and radiotherapy fractionation of the French society of radiotherapy and oncology (SFRO) was reported in this manuscript.

Whole-body hybrid positron emission tomography imaging yields clinically relevant information in the staging and restaging of sinonasal tumors

Background

Whole‐body hybrid positron emission tomography (PET) imaging is increasingly used for sinonasal tumors. However, only empirical data exist on the additional, clinically relevant information derived from these techniques.

Methods

This study included 96 regionalized magnetic resonance imaging (MRI) of the sinonasal tract/neck and separate hybrid FDG‐PET/CT or FDG‐PET/MRI in 74 patients. Additional radiological information (ARI) obtained from each hybrid examination was analyzed and its clinically relevance was determined. Clinically relevant information (CRI) was categorized with regard to primary tumor site, regional lymph node metastases, distant metastases, second primary tumors, and non‐neoplastic findings.

Results

A total of 45/96 (46.9%) hybrid PET examinations revealed ARI. CRI was found in 32/96 (33.3%) examinations and concerned the primary tumor site (6.1%), regional lymph node metastases (4.1%), distant metastases (14.3%), second primary tumors (7.3%), and non‐neoplastic findings (5.1%).

Conclusions

Hybrid PET imaging yields additional radiological information translating into clinically relevant information in a substantial proportion of patients with sinonasal tumors.

Surgery with Post-Operative Endoscopy Improves Recurrence Detection in Sinonasal Malignancies

OBJECTIVE

The mainstay of treatment in sinonasal malignancy (SNM) is surgery, and when combined with chemoradiation therapy, often leads to the best overall prognosis. Nasal endoscopy is essential for post-treatment surveillance along with physical exam and radiologic evaluation. The ability to directly visualize the sinus cavities after surgery may also improve early detection of tumor recurrence and is another reason to potentially advocate for surgery in these patients.

METHODS

A retrospective chart review of medical records of patients with pathologically proven SNM was conducted from 2005 to 2019.

RESULTS

The nasal cavity and maxillary sinus were the most common primary tumor sub-sites. The most common pathology was squamous cell carcinoma (42%). The median time to recurrence was 9.8 months. Recurrence was initially detected endoscopically in 34.3% patients, by imaging in 62.7% patients, and by physical exam in 3.0% patients. 67 (29%) total recurrences were detected on follow-up, of which 46 (68.7%) were local. Twenty-three of the local recurrences were identified via nasal endoscopy. Thirteen recurrences were identified via endoscopic surveillance within the surgically patent paranasal sinuses while 13 were identified within the nasal cavity; 5 patients had multiple sites of recurrence.

CONCLUSION

Local recurrence of SNM is the most common site for recurrent disease and nasal endoscopy identified half of these cases. 50% of these recurrences were within the paranasal sinuses and would not have been easily identified if the sinuses were not open for inspection. Thus, open sinus cavities aid in the detection of tumor recurrence and is another advantage of surgery in the management of SNM.

Extraprimary Local Recurrence of Esthesioneuroblastoma: Case Series and Literature Review

OBJECTIVES

Esthesioneuroblastoma (ENB) is a rare sinonasal malignancy arising from olfactory neuroepithelium. Recurrence typically occurs locoregionally at the primary site or in the form of cervical metastasis. Delayed local recurrence away from the initial primary site is exceedingly rare.

METHODS

Retrospective review of 4 patients with histologically confirmed extraprimary local recurrence of ENB was performed with review of the literature.

RESULTS

All cases initially presented with ENB isolated to the cribriform plate(s) treated with primary surgical resection and adjuvant radiotherapy. The first patient had ENB recurrence 8 years posttreatment involving the right orbit. She later developed metastases to the spine, neck, and mandible requiring composite resection and 4 courses of radiotherapy. The second patient had ENB recurrence of the dorsal septum 9 years posttreatment with cervical metastases requiring septectomy, bilateral neck dissection, and radiotherapy. The third patient had ENB recurrence 7 years posttreatment in the posterior nasopharynx requiring endonasal nasopharyngectomy. Finally, the fourth patient had ENB recurrence 12 years posttreatment in the sphenopalatine foramen, which was endoscopically resected. At the time of this review, all 4 patients were disease free at 32, 21, 4, and 24 months posttreatment follow-ups, respectively.

CONCLUSIONS

This case series describes the rare phenomenon of delayed extraprimary local recurrence of histologically confirmed ENB. Treatment of extraprimary recurrences, analogous to other forms of ENB, should include primary surgical resection with adjuvant radiotherapy for generally favorable outcomes. Long-term close follow-up based on symptoms, endoscopy, and imaging is essential because of the risk of delayed recurrence.

The role of a post therapeutic surveillance program for sinonasal malignancies: Analysis of 417 patients

BACKGROUND

Post therapeutic surveillance of head and neck neoplasms is a still debated issue in the current literature: although different works tried to establish frequency, modality, and efficacy of a routine follow-up, little evidence has been produced, in particular considering only sinonasal malignancies.

METHODS

A retrospective review of patients treated for sinonasal malignancies in a single tertiary center and followed through a regular program of follow-up was carried out. Rate of recurrence, location, timing, diagnosis, and salvage treatment were the main data analyzed.

RESULTS

Of note, 417 patients were included in the study and 117 experienced at least one relapse. Staging, histological type, and previous treatment represent the main clinical factors to be considered to stratify patient's risk of recurrence.

CONCLUSION

A regular post therapeutic surveillance can provide an early recurrence detection for patients treated for sinonasal malignancies, offering opportunity for salvage treatment in a high percentage of patients.

Appropriate timing of surveillance intervals with whole-body 18F-FDG PET/CT following treatment for sinonasal malignancies

PURPOSE

To assess the ideal timing of posttreatment whole-body ¹⁸F-FDG PET/CT examination as routine surveillance to determine local recurrence (R), lymph node metastasis (LM), and distant metastasis (DM) of sinonasal malignancies and to investigate the effect of ¹⁸F-FDG PET/CT on survival.

METHODS

An overall 80 patients who had undergone a total of 197 posttreatment whole-body ¹⁸F-FDG PET/CT examinations for sinonasal malignancy were retrospectively examined after institutional review board approval. Patients were grouped regarding the time intervals (<1 month, 1-3 months, 3-6 months, 6-12 months, 12-18 months and >18 months) after the conclusion of treatment. Differences in diagnostic accuracy due to different follow-up intervals were calculated by receiver operator curves (ROC) and a Cox proportional hazards model was used to assess the prognostic value of surveillance ¹⁸F-FDG PET/CT.

RESULTS

Considering the time intervals of posttreatment ¹⁸F-FDG PET/CT scans, the negative predictive value and positive predictive value of the ¹⁸F-FDG PET/CT examinations to predict overall recurrence in 1-3 months (100 and 100%, respectively) and >18 months (100 and 95%, respectively) were higher than for recurrence detection in <1 month (50 and 100%, respectively), 3-6 months (81 and 93%, respectively), 6-12 months (79 and 87%, respectively), and 12-18 months (75 and 80%, respectively) (p < 0.05). Positive findings on ¹⁸F-FDG PET/CT scans were also independent predictors of poorer overall survival (OS) (p < 0.05).

CONCLUSIONS

Whole-body ¹⁸F-FDG PET/CT is capable of identifying recurrences following treatment, using an optimal time interval for scanning of 1-3 months and >18 months after therapy.

Role of Whole-Body 18F-FDG PET/CT in Screening for Metastases in Newly Diagnosed Sinonasal Malignancies

OBJECTIVE. The aim of this study is to assess the utility of pretreatment whole-body ¹⁸F-FDG PET/CT in screening for distant metastasis (DM) and regional lymphatic metastasis (LM). MATERIALS AND METHODS. Eighty-nine consecutive patients with untreated sinonasal malignant lesions (32 women and 57 men; mean age, 62 years) underwent whole-body FDG PET/CT between January 2009 and August 2017. A retrospective analysis was performed to determine the presence of DM and LM. Any suspected metastases were confirmed by histopathologic analysis or clinical and imaging follow-up in the subsequent 12 months. The statistics were verified by comparing FDG PET/CT results with a reference standard. RESULTS. Overall, the frequency of DM was 24% (21/89), of which 81% (17/21) were identified by whole-body FDG PET/CT. The sensitivity and specificity of FDG PET/CT in predicting DM were 81% (95% CI, 62-95%) and 99% (95% CI, 82-100%), respectively. The most common DM sites were the lungs (n = 6; 28%) and bones (n = 5; 24%), followed by the liver (n = 2; 10%), brain (n = 1; 5%), and spinal canal (n = 1; 5%), with six patients (28%) having DMs at multiple sites. Overall, the frequency of LM according to the reference standard was 20%, of which 83% (15/18) were confirmed with FDG PET/CT. The sensitivity and specificity of FDG PET/CT in detecting LM were 83% (95% CI, 68-97%) and 96% (95% CI, 77-100%), respectively. CONCLUSION. Our study showed that whole-body FDG PET/CT can be used as a screening tool for the detection of DM and LM in sinonasal neoplasms and could be performed as part of the routine pretreatment evaluation of metastatic workup.

Performance of whole-body 18F-FDG PET/CT as a posttreatment surveillance tool for sinonasal malignancies

PURPOSE

To determine the diagnostic utility of posttreatment surveillance whole-body ¹⁸F-FDG PET/CT in detecting local tumor recurrence (R), regional lymph-node metastasis (LM), and distant metastasis (DM) in asymptomatic sinonasal cancer patients.

METHODS

Eighty consecutive patients (53 men, 27 women; mean age, 60 years; range, 28-92 years) who had undergone 197 posttreatment whole-body ¹⁸F-FDG PET/CT examinations for sinonasal malignancies between January 2009 and August 2017 were retrospectively reviewed. ¹⁸F-FDG PET/CT findings were categorized as positive or negative for R, LM, and DM, separately. Outcomes of ¹⁸F-FDG PET/CT scans were compared with the final diagnosis confirmed by histological analysis or follow-up period for a minimum 12 months. The diagnostic accuracy of scans was calculated for each site using contingency tables. Impact on the management of ¹⁸F-FDG PET/CT examinations was additionally evaluated.

RESULTS

¹⁸F-FDG PET/CT scans identified 37/44 of local recurrences, 21/23 of LMs, and 30/37 of DMs. For local recurrence, sensitivity, specificity, positive predictive value, and negative predictive value were 84% (68-97%), 95% (80-100%), 84% (68-97%), and 95% (80-100%), respectively. For LM, the respective values were 91% (75-100%), 99% (83-100%), 91% (75-100%), and 99% (83-100%). For DM, the values were 81% (64-97%), 99% (85-100%), 97% (81-100%), and 96% (81-100%), respectively. ¹⁸F-FDG PET/CT accounted for a change in management of 85% patients with recurrences.

CONCLUSIONS

Whole-body ¹⁸F-FDG PET/CT is a suitable surveillance tool for sinonasal malignancies in detecting locoregional and distant recurrences in asymptomatic patients without any evidence of recurrence on regular follow-up and endoscopy during the posttreatment period.