Role of 18F-FDG PET/CT in Management of High-Grade Salivary Gland Malignancies

Low FDG uptake in lung metastasis despite high FDG uptake in a primary adenoid cystic carcinoma of a sublingual gland

Adenoid cystic carcinoma is a rare malignant tumor that primarily occurs in the salivary glands. There are few reports of sublingual gland adenoid cystic carcinoma with lung metastases on which 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) was performed. We report the case of a 57-year-old Japanese woman with an adenoid cystic carcinoma of the sublingual gland with lung metastases in whom the FDG uptake of the lung metastasis was low despite high FDG uptake in the primary lesion. The pathological examination revealed that solid components were more visible and the Ki-67 index was more positive in the primary lesion compared to the metastatic lesion. We speculate that differences in tumor growth ability might have resulted in the differences in FDG uptake. This case demonstrates that significant differences might occur in the FDG uptake between primary and metastatic tumors.

Topography and probability diagram of cervical and intra-parotid lymph node metastasis in parotid gland cancer

In parotid gland cancer (PGC), cervical lymph node metastasis (LNM) and intra-parotid LNM are known as significant indicators of poor prognosis. However, the topography of LNM in the affected parotid gland and the lymphatic progression of PGC has never been explored in detail. This was a retrospective analysis of data from 423 patients with previously untreated primary PGC (2005 to 2020), excluding patients with squamous cell carcinoma, lymphoma or metastatic disease in the parotid gland. The pattern of LNM was analyzed by neck sub-level and parotid sub-site. Using the conditional probability of neck level involvement, a probability diagram was plotted on several thresholds to visualize the sequential progression of LNM in PGC. The pattern of LNM progression was found to be similar between low- and high-grade pathology, but the incidence differed significantly (8.0% vs. 45.4%). Intra-parotid LNs and level IIa LNs were the most common sites (57.3% and 61.0%) of LNM in PGC, followed by level III (31.7%), Ib (25.6%), IV (22.0%), IIb (20.7%) and Va (20.7%) LNM. In intra-parotid LNs, the incidence of LNM in the deep parotid LNs was relatively low (9.4%); most intra-parotid LNMs were observed in the superficial parotid (90.6%) and peri-tumoral (in contact with the tumor) (31.3%) LNs. LNM to levels Ia, Vb and contra-lateral LNM occurred only in the very late stage. Our results provide detailed information about LNM progression in PGC at the sub-level and can help clinicians decide the treatment extent, including surgery or radiation.

Pathology Mimicking Orofacial Pain

A case of a 64-year-old woman is reported, who developed new-onset pain over a preexisting area of right mandibular fullness. Clinical examination, MRI, and fine-needle aspiration cytology confirmed the diagnosis of a benign parotid gland tumor-pleomorphic adenoma, which was treated by total parotidectomy with complete removal of the tumor. When evaluating a patient with orofacial pain, oral health care providers should be cognizant of all potential differential diagnoses, especially in the setting of red flags such as persistent or enlarging facial swelling/fullness.

Major Salivary Gland Cancer With Distant Metastasis Upon Presentation: Patterns, Outcomes, and Imaging Implications

OBJECTIVES

Given limited data availability on distant metastasis (DM) in major salivary gland (MSG) malignancy presentation, we aimed to evaluate the rate, histologic patterns, location, and predictors of DM at first MSG cancer presentation and suggest potential implications on diagnostic workup.

STUDY DESIGN

Retrospective cohort.

SETTING

Commission on Cancer-accredited hospitals.

METHODS

We included patients in the National Cancer Database (2010-2016) with MSG malignancy. Site and rate of DM were stratified by histologic subtype. Factors predictive of DM at presentation were determined by multivariate regression analysis. Survival analyses were conducted via the Kaplan-Meier method, log-rank test, and Cox regression analysis.

RESULTS

Of 5776 patients with MSG carcinoma, 333 (5.8%) presented with DM. The most common DM site was the lung (57.1%), followed by bone (46.8%) and liver (19.5%). DM was most common in adenocarcinoma-not otherwise specified (15.1%, 132/874) and salivary duct carcinoma (10.4%, 30/288). High-grade mucoepidermoid carcinoma had the highest rate of lung metastases (81.6%, 31/38). Conversely, myoepithelial carcinoma had the highest rate of bone metastases (85.7%, 6/7). DM at presentation was independently associated with an increased mortality risk (hazard ratio, 1.62; 95% CI, 1.40-1.90).

CONCLUSION

We identified a DM rate of 5.8% in MSG malignancy at presentation. Overall 43% of patients presented without DM to the lung but with DM to the bones, liver, and/or brain. The most common metastatic sites differed by tumor histology. Staging with computed tomography neck and chest alone may fail to detect sites of DM; this work can be used for patient counseling in the clinical setting.

KSNM60 in Clinical Nuclear Oncology

Since the foundation of the Korean Society of Nuclear Medicine in 1961, clinical nuclear oncology has been a major part of clinical nuclear medicine in Korea. There are several important events for the development of clinical nuclear oncology in Korea. First, a scintillating type gamma camera was adopted in 1969, which enabled to perform modern oncological gamma imaging. Second, Tc-99 m generator was imported to Korea since 1979, which promoted the wide clinical use of gamma camera imaging by using various kinds of Tc-99 m labeled radiopharmaceuticals. Third, a gamma camera with single photon emission tomography (SPECT) capability was first installed in 1980, which has been used for various kinds of tumor SPECT imaging. Fourth, in 1994, clinical positron emission tomography (PET) scanner and cyclotron with a production of F-18 fluorodeoxyglucose were first installed in Korea. Fifth, Korean Board of Nuclear Medicine was established in 1995, which contributed in the education and manpower training of dedicated nuclear medicine physicians in Korea. Finally, an integrated PET/CT scanner was first installed in 2002. Since that, PET/CT imaging has been a major imaging tool in clinical nuclear oncology in Korea. In this review, a brief history of clinical nuclear oncology in Korea is described.

Comparison of MRI and CT in the Evaluation of Unilateral Maxillary Sinus Opacification

Objectives

To evaluate the diagnostic performance of MRI compared with CT in differentiating neoplastic from infectious/inflammatory causes of complete unilateral maxillary sinus opacification (UMSO). Although MRI is increasingly used, no studies validate its utility compared to CT or nasal endoscopy in this context.

Methods

A retrospective analysis of 49 patients presenting with complete UMSO to a tertiary referral centre was performed, investigated with both CT and MRI. Two head and neck radiologists independently reviewed each imaging modality and recorded both a final diagnosis and Likert-scale diagnostic certainty score. A consensus radiological diagnosis was determined, stratified into potentially neoplastic or infectious/inflammatory aetiology, and compared with nasal endoscopy and final diagnosis. Diagnostic performance and interoperator agreement for predicting neoplasia were calculated.

Results

Both CT and MRI demonstrated high sensitivity and negative predictive value for neoplasm, although MRI was more specific (79%; 95% CI: 60–92%) than CT (14%; 95% CI: 4–32%), with a higher positive predictive value. MRI was more accurate (88%; 95% CI: 75–95%) than CT (49%; 95% CI: 34–64%) in diagnosing neoplasia. MRI had significantly higher diagnostic certainty Likert scores than CT (p < 0.0001 for both observers). Interobserver agreement was fair for CT (kappa coefficient = 0.327) and excellent for MRI (kappa coefficient = 0.918).

Conclusions

MRI is more specific than CT in characterising UMSO, with greater diagnostic certainty and reproducibility. The additive diagnostic value of MRI complements CT, potentially reducing diagnostic delays in some cases and the need for diagnostic endoscopic sinus surgery in others. We recommend MRI incorporation into the diagnostic pathway for patients with UMSO.

Management of Salivary Gland Malignancy: ASCO Guideline

PURPOSE

To provide evidence-based recommendations for practicing physicians and other healthcare providers on the management of salivary gland malignancy.

METHODS

ASCO convened an Expert Panel of medical oncology, surgical oncology, radiation oncology, neuroradiology, pathology, and patient advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 2000 through 2020. Outcomes of interest included survival, diagnostic accuracy, disease recurrence, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 293 relevant studies to inform the evidence base for this guideline. Six main clinical questions were addressed, which included subquestions on preoperative evaluations, surgical diagnostic and therapeutic procedures, appropriate radiotherapy techniques, the role of systemic therapy, and follow-up evaluations.

RECOMMENDATIONS

When possible, evidence-based recommendations were developed to address the diagnosis and appropriate preoperative evaluations for patients with a salivary gland malignancy, therapeutic procedures, and appropriate treatment options in various salivary gland histologies.Additional information is available at www.asco.org/head-neck-cancer-guidelines.

Advanced adenoid cystic carcinoma of maxillary sinus: Rare case report and review of literature

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Adenoid cystic carcinoma of the maxillary sinus is a rare tumor.

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Adenoid cystic carcinoma of the maxillary sinus may represent a serious diagnostic.

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Characterized by very slow growth pattern, high local recurrence rate, and distant metastases mainly to the lungs and bones.

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Poor overall long-term prognosis, compared to other ACCs of the head and neck.

Introduction

Maxillary sinus adenoid cystic carcinoma (MSACC) is a rare malignancy with a propensity for distant metastasis

Case presentation

We report a case of a 55 years-old male who was admitted to our department with a complaint of right nasal obstruction and anosmia. Clinical examination, radiological investigations and histopathological examination found a mass compatible with advanced adenoid cystic carcinoma of the right maxillary sinus. Treatment consisted of radio chemotherapy.

Conclusion

Adenoid cystic carcinoma of the maxillary sinus may represent a serious diagnostic challenge. It should be considered in the differential diagnosis of Sino nasal tumors even if it’s rare.

Distant metastases and synchronous malignancies on FDG-PET/CT in patients with head and neck cancer: a retrospective study

Background

Fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has been proven to be a good method to detect distant spread of head and neck cancer (HNC). However, most prior studies are based on Asian populations and may not be directly transferable to western populations.

Purpose

To investigate the frequency and distribution of distant metastases and synchronous malignancies detected by PET/CT in HNC in a northern Swedish population.

Material and Methods

All primary whole-body FDG-PET/CT examinations performed on the suspicion of HNC (n = 524 patients) between 1 January 2013 and 31 December 2016 at Umeå University Hospital in Sweden were retrospectively reviewed . After the exclusion of 189 examinations without evidence of primary HNC, 335 examinations were analyzed.

Results

Distant metastases were detected in 10 (3%) patients, all with advanced primary tumors corresponding to TNM stage 3–4, most frequently in salivary gland adenocarcinoma, where 50% of patients had distant spread. Four patients had metastases below the diaphragm, representing 20% of the salivary gland malignancies. In the remaining six patients, metastases were supraphrenic, of which all but one were identified by CT alone. Synchronous malignancies were discovered in 14 (4.2%) patients, of which five were below the diaphragm.

Conclusion

The overall frequency of distant spread and synchronous malignancy in primary HNC was generally low. However, the risk for distant metastases below the diaphragm was relatively higher in salivary gland adenocarcinoma, supporting whole-body FDG-PET/CT in the primary diagnostic work-up in these patients.

PET/MR in Head and Neck Cancer - An Update

In academic centers, PET/MR has taken the road to clinical nuclear medicine in the past 6 years since the last review on its applications in head and neck cancer patients in this journal. Meanwhile, older sequential PET + MR machines have largely vanished from clinical sites, being replaced by integrated simultaneous PET/MR scanners. Evidence from several studies suggests that PET/MR overall performs equally well as PET/CT in the staging and restaging of head and neck cancer and in radiation therapy planning. PET/MR appears to offer advantages in the characterization and prognostication of head and neck malignancies through multiparametric imaging, which demands an exact preparation and validation of imaging modalities, however. The majority of available clinical PET/MR studies today covers FDG imaging of squamous cell carcinoma arising from a broad spectrum of locations in the upper aerodigestive tract. In the future, specific PET/MR studies are desired that address specific histopathological tumor entities, nonepithelial malignancies, such as major salivary gland tumors, squamous cell carcinomas arising in specific locations, and malignancies imaged with non-FDG radiotracers. With the advent of digital PET/CT scanners, PET/MR is expected to partake in future technical developments, such as novel iterative reconstruction techniques and deviceless motion correction for respiration and gross movement in the head and neck region. Owing to the still comparably high costs of PET/MR scanners and facility requirements on the one hand, and the concentration of multidisciplinary head and neck cancer treatment mainly at academic centers on the other hand, a more widespread use of this imaging modality outside major hospitals is currently limited.

Surgical extent and role of adjuvant radiotherapy of surgically resectable, low-grade parotid cancer

BACKGROUND

Due to the rarity of low-grade parotid gland cancer and the diversity of histologic subtype, its optimal treatment modalities and prognostic factors have not been established yet. In this study, we aimed to identify the prognostic factors and adequate treatment modalities for patients with low-grade parotid gland cancer.

METHODS

We retrospectively analyzed clinico-pathologic data from 287 patients with low-grade parotid gland cancer from 1999 to 2018.

RESULTS

Recurrence-free survival, disease-specific survival, and overall survival rates at 10 years were 80.6%, 93.9%, and 84.4%, respectively. Among all patients, 56.1% received surgery alone, and the remaining 43.9% received surgery with adjuvant radiotherapy. Resection margin status and TNM stage were significant unfavorable prognostic factors. In patients with T1-2 tumor, surgical extent (total vs. less-than-total) did not show any significant effect on disease recurrence and patients' survival, and the disease was controlled well if a negative surgical margin was obtained after surgery, even with microscopic clear margin of<1 mm. In patients with adverse pathologic features (positive margin, lymphovascular invasion, perineural invasion, extracapsular nodal spread, T3-4, and N1-3), adjuvant radiotherapy significantly decreased loco-regional recurrence.

CONCLUSIONS

Oncological outcomes were good in patients with low-grade parotid gland cancer with surgery and radiotherapy. In patients with T1-2 low-grade parotid gland cancer, surgery alone showed good local control rate regardless of the extent of surgery, if a negative surgical margin was obtained after surgery. Adjuvant radiotherapy played a significant role in controlling loco-regional recurrence in patients with adverse pathologic features.

Cancers of the Major Salivary Gland

Salivary gland malignancies are rare tumors that comprise multiple histologic entities with diverse clinical behavior. Mucoepidermoid carcinoma is the most frequent primary salivary malignancy, followed by adenoid cystic and acinic cell carcinoma. Although most salivary malignancies are asymptomatic, presentation with a rapidly enlarging mass may be accompanied by pain, functional neurologic deficits, soft-tissue invasion, or nodal enlargement. Assessment of clinical behavior and physical exam greatly contributes to diagnostic workup. Preoperative imaging, to include ultrasound, computed tomography, or magnetic resonance imaging, may assist with surgical planning. Limitations of preoperative fine-needle aspiration cytology mean that, in some cases, definitive histologic diagnosis may not be established until therapeutic surgery is undertaken. Treatment strategies rely on oncologic resection of the primary site with negative margins as well as adjuvant radiotherapy in patients with high-risk features, such as high-grade histology, advanced T class, or perineural invasion. Regional lymphadenectomy is recommended for involved nodal basins. Patients with clinically node-negative disease at high risk for occult nodal metastases may be considered for elective lymphadenectomy or radiotherapy. Use of chemotherapy in the adjuvant setting, in combination with radiotherapy, remains controversial. The rate of objective response to palliative chemotherapy in recurrent or metastatic salivary gland malignancy remains low. In studies that include a significant proportion of adenoid cystic carcinomas, whether disease stability represents an indolent disease process or the true effect of a therapeutic drug may be difficult to discern. Recognition of genetic alterations and protein expression unique to salivary malignancies presents exciting new opportunities for molecularly targeted therapy, although the response to molecularly targeted therapy in studies has been modest thus far.

[Delineation of the primary tumour clinical target volumes and neck node levels selection of parotid cancers]

Salivary glands tumours are uncommon tumours showing a large diversity of histological types. This article presents a synthesis of patterns and paths of invasion of parotid glands tumours in order to propose an approach of the delineation of primary tumour clinical target volumes and of the selection of lymph nodes target volumes. This article does not discuss treatment indications but defines clinical target volumes to treat if radiotherapy is indicated. Postoperative situation being the most frequent, the delineation of primary tumour clinical target volume is based on an anatomical approach.

Solitary pulmonary metastasis from a gingival cancer of 36 years ago: A case report

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An adenoid cystic carcinoma is characterized by a long-term behavior and late recurrences.

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The recurrences of ACC after more than 30 years have not been reported.

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The precise preoperative diagnosis was very difficult due to a history of tongue cancer one year previously in the present case.

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We should never overlook a history of any malignancy even if it is over 30 years prior.

Introduction

Unlike a squamous cell carcinoma (SqCC), an adenoid cystic carcinoma (ACC) is an uncommon histology of all head and neck cancers. The clinical significance of a pulmonary metastasectomy differs greatly between these two types of cancers. A solitary pulmonary nodule in a patient with a history of both these different malignancies is a diagnostic and therapeutic challenge.

Presentation of case

An 81-year-old woman presented with a right lung nodule detected by chest computed tomography (CT) one year after a tongue SqCC surgery. She had a remote history of gingival cancer 36 years prior, which was not assessed in detail during the initial work up. We suspected that the nodule was a primary lung cancer and she underwent a right basal segmentectomy. Histology revealed an ACC, which was proven to be a metastasis from the gingival cancer.

Discussion

An ACC is an uncommon type of cancer arises mainly in the salivary glands. It is characterized by a long-term behavior and the histology of ACC is a favorable prognostic factor. With its favorable histology and disease free interval of over 30 years, a better outcome would be expected than that of a primary lung tumor or a metastasis from the tongue SqCC. Furthermore, we could have made a differential diagnosis of a metastatic ACC before the surgery with more careful research for a previous history of a gingival cancer.

Conclusion

Our case emphasized that a precise history taking of any malignancy, even if that of more than 30 years prior, is crucial.

18 F-FDG PET/MRI vs MRI in patients with recurrent adenoid cystic carcinoma

OBJECTIVES

To evaluate and compare the diagnostic potential of ¹⁸ F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging (¹⁸ FDG-PET/MRI) and MRI for recurrence diagnostics after primary therapy in patients with adenoid cystic carcinoma (ACC).

METHODS

A total of 32 dedicated head and neck ¹⁸ F-FDG PET/MRI datasets were included in this analysis. MRI and ¹⁸ F-FDG PET/MRI datasets were analyzed in separate sessions by two readers for tumor recurrence or metastases.

RESULTS

Lesion-based sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 96%, 84%, 90%, 93%, and 91% for ¹⁸ F-FDG PET/MRI and 77%, 94%, 95%, 73%, and 84% for MRI, resulting in a significantly higher diagnostic accuracy of ¹⁸ F-FDG PET/MRI compared to MRI (P < .005).

CONCLUSION

¹⁸ F-FDG PET/MRI is superior to MRI in detecting local recurrence and metastases in patients with ACC of the head and neck. Especially concerning its negative predictive value, ¹⁸ F-FDG PET/MRI outperforms MRI.

Treatment outcomes in metastatic and localized high-grade salivary gland cancer: high chance of cure with surgery and post-operative radiation in T1-2 N0 high-grade salivary gland cancer

BACKGROUND

High-grade salivary gland cancer is a distinct clinical entity that has aggressive disease progression and early systemic spread. However, because of the rarity of the disease, the clinical outcomes, prognostic factors and clinical decision on the optimal treatments have not been fully understood.

METHODS

In this study, we retrospectively analyzed the clinical data of 124 patients with high-grade salivary gland cancers and performed multivariate survival analyses to evaluate the clinico-pathological factors affecting the treatment outcomes.

RESULTS

The 5-year disease-specific survival was 63.4% in patients with high-grade salivary gland cancers. Among the clinico-pathological factors, presence of lymph node metastasis (hazard ratio 5.63, 95% confidence interval 2.64-12.03, P < 0.001) and distant metastasis (hazard ratio 4.59, 95% confidence interval 2.10-10.04, P < 0.001) at diagnosis were the most potent unfavorable prognostic factors. Importantly, patients with early-stage disease (T1-2N0M0) showed apparently a relatively excellent prognosis (93.2% 5-year disease-specific survival); meanwhile N (+) and M1 status at diagnosis resulted in dismal outcomes (44.6 and 21.1% 5-year disease-specific survival, respectively). On comparing surgery alone as a treatment modality, surgery plus postoperative radiation significantly benefited the patients, but the difference between adjuvant radiation and chemoradiation was not found to be significant. Pathological subtypes of high-grade salivary gland cancers were not significantly associated with prognosis.

CONCLUSIONS

Despite of an overall unfavorable prognosis in high-grade salivary gland cancer, patients with early-stage disease are expected to have excellent prognosis (over 90% survival rates) with surgery plus adjuvant radiation, which may implicate the patients' consultation, therapeutic decision making, and the need for early detection of the disease.

Extensive Regional Metastasis of High-Grade Mucoepidermoid Carcinoma of an Unknown Primary Tumor

PURPOSE

Mucoepidermoid carcinoma (MEC) is the most common salivary carcinoma. It arises most frequently in the major salivary glands, but can also arise in minor glands or intraosseous sites. MEC of an unknown primary occurs very rarely. The present report documents only the third case reported in medical studies.

METHODS

A 66-year-old man with previous carcinoma in situ (CIS) of the left posterior oral tongue that had been excised in 2004 and again in 2010 presented with a hard lymph node, 3 × 2 cm at level II of the right neck in July 2015. Positron emission tomography-computed tomography (PET-CT) revealed multiple, bilateral cervical lymphadenopathy, with no primary site identified. Fine needle aspiration biopsy and cytologic examination from the right neck was positive for malignancy, suggestive of metastatic squamous cell carcinoma. Panendoscopy and biopsy revealed CIS at the tongue bases and tonsils bilaterally (p16-negative). The patient's case was presented to a tumor board, and definitive concurrent cispl.atin-based chemoradiation was recommended for TisN2cM0, stage IVA oropharyngeal CIS, which was completed in November 2015. PET-CT in January 2015 showed complex interval changes, with some areas demonstrating improvement (ie, no uptake in the left neck) and worsening in others (ie, increased metabolic activity in the right neck), suggestive of residual disease. Repeat PET-CT in March 2016 showed increased nodal involvement and increasing standardized uptake value. Bilateral modified radical neck dissection was undertaken, and histologic examination showed high-grade MEC in 51 of 61 lymph nodes with extracapsular spread and soft tissue involvement.

RESULTS

The patient died in May 2016 at 2 months after surgery.

CONCLUSIONS

Metastatic MEC of an unknown primary is a diagnostic challenge. PET-CT might not be the most reliable diagnostic investigation to identify the primary or metastatic foci, such as was demonstrated in the present case.

Cancers of major salivary glands

Major salivary gland malignancies are a rare but histologically diverse group of entities. Establishing the diagnosis of a malignant salivary neoplasm may be challenging because of the often minimally symptomatic nature of the disease, and limitations of imaging modalities and cytology. Treatment is centered on surgical therapy and adjuvant radiation in selected scenarios. Systemic therapy with chemotherapeutic agents and monoclonal antibodies lacks evidence in support of its routine use.

Facial Paralysis Secondary to Extensive Perineural Spread of Adenocarcinoma of the Parotid Gland Identified by PET/CT

Brain MRI in an 82-year-old man with presumed Bell's palsy revealed a clinically unsuspected right parotid gland mass but no other acute findings. Biopsy revealed poorly differentiated adenocarcinoma. Staging F-FDG PET/CT revealed an FDG-avid parotid mass, abnormal FDG uptake along the course of the facial nerve from mass to skull base, and multiple FDG-avid right level II neck lymph nodes and hepatic metastases. The PET/CT findings and prolonged clinical course suggest that diffuse perineural spread of tumor from a smoldering parotid neoplasm, and not idiopathic Bell's palsy, was responsible for the patient's facial paralysis.

Prognostic Factors and Treatment Outcomes of Parotid Gland Cancer

Objective

To investigate the treatment outcomes of parotid gland cancer at a single center over a 10-year period and to evaluate the prognostic significance of maximum standardized uptake value.

Study Design

Retrospective case series with chart review.

Setting

Academic care center.

Subjects and Methods

Ninety-eight patients with primary parotid gland cancer who were surgically treated at Yonsei University Head & Neck Cancer Clinic between January 1999 and December 2008 were analyzed. Patient data were collected retrospectively from medical charts. The investigators analyzed the association of clinicopathological factors and maximum standardized uptake value on 18F-fluorodeoxyglucose positron emission tomography–computed tomography scan with disease-specific survival.

Results

Mean patient age was 49.7 years. Mean follow-up was 48.8 months. Thirty-three, 40, 30, and 23 patients had stage I, II, III, and IVA disease, respectively. Mucoepidermoid carcinoma was the most common histologic type (34.7%), followed by acinic cell carcinoma (27.6%). Eighteen patients (18.4%) experienced recurrences (mean recurrence gap, 20.6 months; range, 2-87 months). Five- and 10-year disease-specific survival rates were 93.6% and 81.8%, respectively. In the univariate analysis, pathologic T stage, pathologic lymph node status, resection margin, external parenchymal extension, and maximum standardized uptake value were significantly associated with disease-specific survival. Pathologic lymph node status and maximum standardized uptake value were independent prognostic factors in the multivariate analysis.

Conclusion

Our single-center experience with parotid gland cancer treatment is consistent with the literature. Cervical lymph node metastasis and high maximum standardized uptake value are associated with poor survival in parotid gland cancer.

Adenoid cystic carcinoma of the head and neck--An update

This article provides an update on the current understanding of adenoid cystic carcinoma of the head and neck, including a review of its epidemiology, clinical behavior, pathology, molecular biology, diagnostic workup, treatment and prognosis. Adenoid cystic carcinoma is an uncommon salivary gland tumor that may arise in a wide variety of anatomical sites in the head and neck, often with an advanced stage at diagnosis. The clinical course is characterized by very late recurrences; consequently, clinical follow-up should extend at least >15 years. The optimal treatment is generally considered to be surgery with postoperative radiotherapy to optimize local disease control. Much effort has been invested into understanding the tumor's molecular biological processes, aiming to identify patients at high risk of recurrence, in hopes that they could benefit from other, still unproven treatment modalities such as chemotherapy or biological therapy.

Patterns of spread of head and neck adenoid cystic carcinoma

We present a review of head and neck adenoid cystic carcinoma (ACC). Imaging features of the primary tumour, patterns of locoregional spread, and distant metastasis with emphasis on perineural extension and imaging pitfalls are discussed with illustrated examples.

(18)FDG-PET/CT for the detection of regional nodal metastasis in patients with head and neck cancer: a meta-analysis

We performed a meta-analysis to evaluate the role of (18)FDG-PET/CT for detection of regional nodal metastasis in patients with head and neck cancer (HNC). Studies about (18)FDG-PET/CT were systematically searched in the MEDLINE and EMBASE databases. The Stata software was used to obtain pooled estimates of sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio for (18)FDG-PET/CT. We also compared the performance of (18)FDG-PET/CT with that of conventional imaging (CT, MRI, and CT/MRI) by analyzing studies that had also used conventional imaging on the same patients. 24 articles bulled all inclusion criteria (1270 patients). The pooled per-patient, per-neck-side, and per-neck-level sensitivities/specificities for (18)FDG-PET/CT were 0.91/0.87, 0.84/0.83, and 0.80/0.96, respectively. Across 13 studies (3460 neck levels) with per-neck-level data, the sensitivity and specificity of PET-CT were 0.84 and 0.96, and of conventional imaging were 0.63 and 0.96, respectively. (18)FDG-PET/CT has good diagnostic performance for the detection of regional nodal metastasis in HNC patients. Compared with conventional imaging, (18)FDG-PET/CT may have higher per-neck-level sensitivity.

Prevalence and risk of malignancy of focal incidental uptake detected by fluorine-18-fluorodeoxyglucose positron emission tomography in the parotid gland: a meta-analysis

This study aimed at performing a meta-analysis on the prevalence and risk of malignancy of focal parotid incidental uptake (FPIU) detected by hybrid fluorine-18-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) or (18)F-FDG PET alone. A comprehensive literature search of studies published up to July 2014 was performed. Records reporting at least 5 FPIUs were selected. Pooled prevalence and malignancy risk of FPIU were calculated including 95 % confidence intervals (95 % CI). Twelve records were selected for our meta-analysis. Pooled prevalence of FPIU detected by (18)F-FDG PET or PET/CT was 0.6 % (95 % CI 0.4-0.7 %), collecting data of 220 patients with FPIU. Overall, 181 FPIUs underwent further evaluation and 165 FPIUs were pathologically proven. Pooled risk of malignancy was 9.6 % (95 % CI 5.4-14.8 %), 10.9 % (95 % CI 5.8-17.3 %) and 20.4 % (95 % CI 12.3-30 %), considering all FPIUs detected, only those which underwent further evaluation and only those pathologically proven, respectively. Selection bias in the included studies, the heterogeneity among studies and the publication bias are limitations of our meta-analysis. Overall FPIUs are observed in about 1 % of (18)F-FDG PET or PET/CT scans and they are benign in most of the cases. Nevertheless, further evaluation is needed whenever FPIUs are detected by (18)F-FDG-PET or PET/CT to exclude malignant lesions or with possible malignant degeneration. Prospective studies are needed to confirm the findings reported by our meta-analysis.

Salivary gland tumors: A 20-year review of clinical diagnostic accuracy at a single center

Obtaining reliable pre-operative diagnosis is crucial in planning treatment for patients with salivary gland tumors. The purpose of this study was to evaluate the accuracy of pre-operative clinical diagnosis of salivary gland tumors managed at a single tertiary university hospital over a period of 20 years. A retrospective analysis of the period between 1992 and 2011 was carried out to review the cases of patients with salivary gland tumors. A total of 101 patients were enrolled and general data were described. Clinical diagnosis was compared with the final pathological diagnosis to reveal the clinical diagnostic accuracy. Of the parotid and submandibular gland tumors, 86 and 67% were benign, respectively. The clinical diagnostic accuracies for diagnosis of parotid tumors as benign or malignant were 100 and 57%, respectively. The clinical diagnostic accuracies for diagnosis of submandibular tumors as benign or malignant were 67%. Therefore, the overall clinical judgment of benign and malignant tumors in the submandibular gland is unreliable. The accuracy for a parotid tumor to be clinically interpreted as benign was 100%. While it is difficult to draw any conclusion for non-parotid gland tumors, surgical intervention should be recommended in patients with parotid tumors clinically suspected to be malignant, and all submandibular, sublingual and minor salivary gland tumors.

Adenoid cystic carcinoma of the maxillary sinus: CT and MR imaging findings

OBJECTIVE

The purpose of this study was to determine whether adenoid cystic carcinomas (ACCs) of the maxillary sinus have features on CT and MR imaging.

MATERIALS AND METHODS

Nine patients with histopathologically proved maxillary sinus ACCs were included. The growth pattern was classified as expansile or destructive types on the basis of CT images. CT images were also reviewed for adjacent bony defects and MR images were reviewed for tumor extension. Fluid accumulation in the ipsilateral maxillary sinus was also assessed.

RESULTS

The tumors had caused adjacent bony expansion with minimal bony defects in 4 patients whereas those in the remaining 5 patients had caused extensive destruction of adjacent bones comprising the maxillary sinus walls. Nasal cavity invasion was observed in 7 patients, retroantral fat pad invasion in 5, pterygopalatine fossa invasion in 4, and orbital invasion in 3. All 4 expansile ACCs were accompanied by accumulation of a small amount of fluid in the surroundings of the tumors, which was revealed as hyperintensity on T1-weighted images.

CONCLUSION

The growth pattern of maxillary sinus ACCs can be classified into an expansile type with minimal bony defects and a destructive type with extensive bony defects.

The Value of F-18 FDG PET for Planning Treatment and Detecting Recurrence in Malignant Salivary Gland Tumors: Comparison with Conventional Imaging Studies

PURPOSE

To assess the value of F-18 FDG PET/CT for detecting cervical lymph node (LN) metastasis and recurrence, as well as planning treatment, and to compare the accuracy of PET/CT with conventional imaging studies (CIS) in patients with malignant salivary gland tumor (SGT).

METHODS

Staging and follow-up PET/CT for SGT were retrospectively reviewed. Enhanced CT and/or MRI of the neck were performed within 1 month of PET/CT. Final diagnosis was based on histology from cervical LN dissection and biopsy or a minimum 6 months of clinical and imaging follow-up. We compared the performance of PET/CT in initial cervical LN staging and recurrence detection with that of CIS.

RESULTS

A total of 184 PET/CT exams of 66 patients were included, and 34 initial staging and 150 surveillance PET/CT exams were performed. The initial cervical LN detection sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 60.9 %, 89.2 %, 84.0 %, 56.0 %, and 91.0 % for visual analysis on PET/CT, 39.1 %, 95.0 %, 84.8 %, 64.3 %, and 87.4 % for semiquantitative analysis on PET/CT, and and 43.5 %, 94.1 %, 84.8 %, 62.5 %, and 88.1 % for CIS. The sensitivity of visual analysis on PET/CT was significantly higher than that of semiquantitative analysis on PET/CT and CIS (p = 0.0009 and 0.0086). In 5 of 34 initial staging patients (14.7 %), the treatment plan was changed from curative surgery to palliative therapy. The performance of follow-up PET/CT showed no significant difference compared with CIS.

CONCLUSION

PET/CT showed comparable performance with CIS for cervical LNs staging. Initial PET/CT changed treatment plans in 14.7 % of patients. However, PET/CT offered no additional advantage for detecting locoregional recurrence.

Utility of (18)F-FDG PET-CT in staging and restaging of patients with malignant salivary gland tumours: a single-institutional experience

OBJECTIVE

The aim of this study was to evaluate the clinical utility of (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography-computed tomography (PET-CT) in staging and restaging of patients with malignant primary salivary gland tumours.

METHODS

Data pertaining to 30 patients (age: 43.8±16.8 years; male/female: 20/10) with histopathologically proven malignant primary salivary gland tumours who underwent 36 F-FDG PET-CTs were retrospectively analysed. Ten PET-CTs were performed for staging and 26 for restaging. The primary site was the parotid gland in 22 patients, the submandibular gland in seven and the minor salivary gland in one patient. (18)F-FDG PET-CT images were revaluated by two nuclear medicine physicians in consensus. Findings were grouped into local disease, nodal disease and distant metastasis. Results were compared with those of conventional imaging modalities [CIM (CT/ultrasound/bone scintigraphy)] when available (n=28). Clinical or imaging follow-up (minimum 6 months) data along with histopathological information (when available) were taken as the reference standard.

RESULTS

Overall, 25 PET-CTs were positive and 11 were negative for disease. (18)F-FDG PET-CT showed local disease in 21 patients, nodal disease in 17 and distant metastasis in nine (lungs, four; liver, three; bones, four; and thyroid, one). Twenty-three PET-CTs were true positive, nine were true negative, two were false positive and two were false negative. The overall sensitivity of (18)F-FDG PET-CT was 92%, specificity was 82%, positive predictive value was 92%, negative predictive value was 82% and accuracy was 89%. No significant difference was seen in the accuracy of PET-CT between the staging and restaging groups (100 vs. 85%; P=0.468). In patients for whom comparable CIM data were available (n=28), PET-CT did not show any significant advantage over CIM (P=0.012) but was more specific (71 vs. 43%).

CONCLUSION

(18)F-FDG PET-CT shows high accuracy in staging and restaging of patients with malignant primary salivary gland tumours. It is more specific than CIM for this purpose.

Lung metastasis of adenoid cystic carcinoma, which mimicked primary lung cancer

We report a case of adenoid cystic carcinoma of the submandibular gland where pulmonary metastasis occurred twice 16 years after resection, and each metastasis mimicked primary lung adenocarcinoma in imaging findings. The first pulmonary relapse was clinically diagnosed as primary lung adenocarcinoma and intraoperative pathological examination showed that the tumor was an adenocarcinoma; lobectomy with mediastinal lymph node dissection was performed. However, postoperative immunohistochemical analysis showed that the tumor was a metastatic adenoid cystic carcinoma. During the secondary pulmonary relapse, although the tumor was correctly diagnosed as a metastatic adenoid cystic carcinoma by intraoperative examination, it again mimicked primary lung adenocarcinoma.

Prognostic value of preoperative metabolic tumor volume and total lesion glycolysis measured by 18F-FDG PET/CT in salivary gland carcinomas

Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) from (18)F-FDG PET/CT are emerging prognostic biomarkers in various human cancers. This study examined the prognostic value of these metabolic tumor parameters measured by pretreatment (18)F-FDG PET/CT in patients with salivary gland carcinomas.

METHODS

Forty-nine patients with intermediate- or high-grade salivary gland carcinomas who underwent definitive surgery with or without radiotherapy or chemoradiotherapy were evaluated preoperatively by (18)F-FDG PET/CT. Maximum standardized uptake values (SUV max), MTV, and TLG were measured for each patient. Univariate and multivariate analyses were used to identify clinicopathologic and imaging variables associated with progression-free survival (PFS) and overall survival (OS). Univariate analyses included the following variables: age, sex, pT and pN classifications, overall pTNM stage, histologic grade, resection margin, tumor lymphovascular invasion and perineural invasion, postoperative adjuvant therapy, gross total volume, SUV max, MTV, and TLG.

RESULTS

The 3-y PFS and OS rates for all study patients were 66.9% and 81.6%, respectively. The median SUV max, MTV, and TLG were 5.1 (range, 1.7-21.5), 16.2 mL (1.0-115.1 mL), and 24.4 g (2.1-224.4 g), respectively. Univariate analyses showed that there were significant correlations between pT classification, pN classification, MTV, and TLG and both PFS and OS (P < 0.05). However, SUV max was not associated with either PFS (P = 0.111) or OS (P = 0.316). Multivariate analyses revealed that MTV (P = 0.011; hazard ratio, 11.50; 95% confidence interval, 1.45-91.01) and TLG (P = 0.038; hazard ratio, 3.55; 95% confidence interval, 1.07-11.76) were independent variables for PFS.

CONCLUSION

Pretreatment values of MTV and TLG are independent prognostic factors in patients with intermediate or high-grade salivary gland carcinomas.

The influence of interpreters' professional background and experience on the interpretation of multimodality imaging of pulmonary lesions using 18F-3'-deoxy-fluorothymidine and 18F-fluorodeoxyglucose PET/CT

Objective

Based on the results of a recently accomplished multicenter clinical trial for the incremental value of a dual-tracer (18F-FDG and 18F-FLT), dual-modality (PET and CT) imaging in the differential diagnosis of pulmonary lesions, we investigate some issues that might affect the image interpretation and result reporting.

Methods

The images were read in two separate sessions. Firstly the images were read and reported by physician(s) of the imaging center on completion of each PET/CT scanning. By the end of MCCT, all images collected during the trial were re-read by a collective of readers in an isolated, blinded, and independent way.

Results

One hundred sixty two patients successfully passed the data verification and entered into the final analysis. The primary reporting result showed adding 18F-FDG image information did not change the clinical performance much in sensitivity, specifity and accuracy, but the ratio between SUVFLT and SUVFDG did help the differentiation efficacy among the three subgroups of patients. The collective reviewing result showed the diagnostic achievement varied with reading strategies. ANOVA indicated significant differences among ¹⁸F-FDG, ¹⁸F- FLT in SUV (F = 14.239, p = 0.004). CT had almost the same diagnostic performance as 18F-FLT. When the 18F-FDG, 18F- FLT and CT images read in pair, both diagnostic sensitivity and specificity improved. The best diagnostic figures were obtained in full-modality strategy, when dual-tracer PET worked in combination with CT.

Conclusions

With certain experience and training both radiologists and nuclear physicians are qualified to read and to achieve the similar diagnostic accuracy in PET/CT study. Making full use of modality combination and selecting right criteria seems more practical than professional back ground and personal experience in the new hybrid imaging technology, at least when novel tracer or application is concerned.

18FDG-PET/CT for the detection of regional nodal metastasis in patients with primary head and neck cancer before treatment: a meta-analysis

BACKGROUND

We performed a meta-analysis to evaluate the role of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)FDG-PET/CT) in the detection of regional nodal metastasis in patients with primary head and neck cancer before treatment.

MATERIALS AND METHODS

Studies about (18)FDG-PET/CT for the detection of regional nodal metastasis in patients with primary HNC were systematically searched in the MEDLINE, EMBASE, and EBM Review databases from January 1, 2000 to July 25, 2012. A software called "Stata 12.0" was used to obtain pooled estimates of sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio for PET/CT. We also calculated hierarchic summary receiver operating characteristic (HSROC) curves and area under the curves.

RESULTS

14 articles (742 patients) fulfilled all inclusion criteria. The pooled sensitivity, and specificity with 95% confidence interval for PET/CT on a per-neck-side analysis were 0.84 (0.77-0.89) and 0.84 (0.78-0.89). The corresponding values for PET/CT on a per-nodal-level analysis 0.84 (0.78-0.88) and 0.96 (0.94-0.98).

CONCLUSIONS

(18)FDG-PET/CT had good diagnostic performance for the detection of regional nodal metastasis in patients with primary head and neck cancer before treatment.

Diagnostic accuracy of fine needle aspiration cytology for high-grade salivary gland tumors

BACKGROUND

Preoperative differentiation between high-grade malignancy and others (benign or low-grade tumors) is more important than differentiation between malignant and benign tumors for surgical planning, treatment outcome, and prognosis in salivary gland tumors. Fine needle aspiration cytology (FNAC) has a relatively low sensitivity for differentiating malignant from benign salivary tumors. However, the diagnostic performance of FNAC has not been studied in predicting high-grade salivary malignancy, which can significantly affect patient care.

METHODS

Experienced cytopathologists reevaluated the adequate FNAC on 521 salivary gland tumors. The diagnostic performances of FNAC for total malignancy and high-grade malignancy were calculated, and the results were validated in independent 105 cases. In cases of high-grade cancer on FNAC, we recorded the additional diagnostic procedures and the change of surgical extent to decide how FNAC impacts clinical practice.

RESULTS

The sensitivity, specificity, and diagnostic accuracy of FNAC in differentiating malignant from benign tumors were 64.2 % (95 % confidence interval 52.3-75.0), 98.4 % (96.5-99.3), and 92.1 % (89.1-94.6). Meanwhile, FNAC predicted high-grade malignancy accurately (94.6 % [80.0-99.5], 99.2 % [97.8-99.7], 98.9 % [97.3-99.6], respectively), a finding reproduced with similar results in the validation set. FNAC indicative of high-grade malignancy added additional imaging assessments in 94.9 %, frozen biopsy samples during surgery (tumor and lymph nodes) in 71.2 %, and changed the extent of surgery in 59.0 %.

CONCLUSIONS

FNAC has an excellent diagnostic performance in discriminating high-grade salivary cancer, which guides clinical decision and surgical planning in salivary gland tumors.