Assessment of cervical lymph node metastasis with different imaging methods in patients with head and neck squamous cell carcinoma

OBJECTIVE: To determine the predictive value of different imaging methods,-computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US), and single-photon emission tomography (SPECT),-for cervical node metastasis. DESIGN: Prospective clinical trial. SETTING: An academic otolaryngology department. METHODS: Twenty-three consecutive patients with head and neck malignancy were prospectively evaluated for the presence of cervical lymphadenopathy. All patients underwent clinical, CT, MRI, US, and SPECT examinations. Neck dissection was performed for 31 neck sides, and the results of the preoperative evaluation were confirmed by the surgical and histopathologic findings. MAIN OUTCOME MEASURES: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated for each method and a comparison of the methods was done. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CT, MRI, US, and SPECT were 77.7%, 85.7%, 91.3%, 66.6%, and 80.4%; 59.2%, 92.8%, 94.1%, 54.1%, and 70.7%; 81.4%, 64.2%, 81.4%, 64.2%, and 75.6%; 55.5%, 92.8%, 93.7%, 52.0%, and 68.2%, respectively. Both CT and US were found to be superior to clinical examination. There was no statistically significant difference between US and CT. US was found to be superior to MRI and SPECT in detecting cervical node metastasis. CT was also superior to SPECT. CONCLUSION: Our data show that, despite high specificity rates, especially with SPECT, none of the currently available imaging methods are reliable in evaluating the occult regional metastasis because the negative predictive values of all of these methods are rather low.     

Positron emission tomography in the management of unknown primary head and neck carcinoma

OBJECTIVE: To assess the role of positron emission tomography (PET) in the management of unknown primary carcinoma of the head and neck region. DESIGN AND SETTING: Prospective case series at an academic medical center. PATIENTS: Twenty-six patients with an open excisional biopsy or a fine-needle aspiration biopsy finding that confirmed squamous cell carcinoma of the cervical lymph nodes and no visible primary tumor (as determined by results of a comprehensive physical examination and computed tomography and/or magnetic resonance imaging) underwent PET. The standard evaluation consisted of a comprehensive head and neck examination that included fiberoptic laryngoscopy/nasopharyngoscopy, computed tomography and/or magnetic resonance imaging, and PET followed by panendoscopy with selected biopsies and tonsillectomy. MAIN OUTCOME MEASURES: Sensitivity, specificity, and positive and negative predictive values of PET to detect an occult primary tumor. RESULTS: The PET detected 8 occult primary tumors in 26 patients (detection rate, 30.8%). Four occult primary tumors (2 at the base of the tongue and 2 in the tonsil) were detected during routine panendoscopy with negative PET findings. The sensitivity of PET was 66.0%, with a specificity of 92.9%. The positive predictive value was 88.8%, and the negative predictive value was 76.5%. CONCLUSIONS: Positron emission tomography can be a valuable tool to identify a subset of patients with an occult primary tumor in the head and neck region. In addition, it can be used to screen for primary tumors below the clavicle. Early identification of the primary tumor may allow for more accurate tumor staging and targeted radiotherapy to minimize adverse effects and complications. A normal PET finding, however, does not eliminate the need for a careful panendoscopy with directed biopsies and tonsillectomy.     

Positron emission tomography in the evaluation of synchronous lung lesions in patients with untreated head and neck cancer

BACKGROUND: Positron emission tomography (PET) with the glucose analogue fludeoxyglucose F 18 uses the increased glucose uptake that is observed in neoplastic cells. It can differentiate between benign and malignant pulmonary lesions in patients with lung tumors. Applications of PET in extracranial head and neck neoplasms have included evaluating patients with unknown primary lesions, detecting primary and recurrent head and neck tumors, monitoring response to radiotherapy, and evaluating the N0 neck in oral cavity carcinomas. Its role in determining the presence of synchronous lung lesions has not been defined. PATIENTS AND METHODS: A retrospective review of 115 patients who underwent PET between October 1994 and October 1996 was performed to evaluate extracranial head and neck neoplasms. Fifty-nine (51%) previously untreated patients with squamous cell carcinoma of the upper aerodigestive tract were analyzed. RESULTS: Fifteen patients (25%) had PET scans that were positive for synchronous lung lesions. Five patients had a disease process that did not warrant further investigation; they did not have pathological confirmation of their lung lesions. Of these, 3 died of disease within 2 months of the diagnosis of primary head and neck squamous cell carcinoma, 1 was unavailable for follow-up, and 1 had lung lesions that were considered metastatic and no pathological confirmation of lung lesions was obtained. The remaining 10 patients with positive PET scan findings were investigated further: 8 patients had biopsy-confirmed lung lesions; 5 patients had positive findings on chest x-ray films; 8 had positive findings on computed tomographic scans; and 3 had positive findings on bronchoscopy. The results of 2 PET scans were false-positive. The PET scans were important in altering treatment in 3 patients; of these, 3 had negative findings on chest x-ray films, 2 had positive findings on computed tomographic scans, and 1 had positive findings on bronchoscopy. CONCLUSIONS: The overall sensitivity, positive predictive value, and accuracy of PET were 100%, 80%, and 80%, respectively. The overall accuracy of radiography of the chest, computed tomography of the chest, and bronchoscopy was 70%, 90%, and 50%, respectively. The accuracy of PET over bronchoscopy was statistically significant (P<.05). PET appears to be a promising imaging modality for the detection of synchronous lung lesions in patients with negative findings on chest x-ray films.     

Results of pretherapeutic lymph node diagnosis in head and neck tumors. Clinical value of 18-FDG positron emission tomography (PET)

BACKGROUND: Histological studies demonstrate that there is a high percentage of occult nodal metastasis in head and neck malignomas. Patients with positive lymph nodes have a comparatively worse prognosis. A neck dissection is required in these cases. By demonstrating morphological abnormalities, imaging procedures like ultrasound, computer tomography (CT), and magnetic resonance imaging (MRI) can provide important initial informations about possible malignant alteration of the lymph nodes. Positron emission tomography (PET) allows functional metabolic imaging of a suspected tumor site. The aim of this study was a comparative evaluation of different diagnostic procedures with special emphasis on the value of PET in the pretherapeutic diagnosis of nodal spread in head and neck cancer. PATIENTS AND METHODS: Forty patients (28 male and 12 female) with a suspected malignoma in the head and neck region underwent clinical examination including palpation of the neck sides, ultrasound, CT, and PET to detect a nodal spread of the malignancy. Fifty neck dissections were performed in 28 patients. Lymph node biopsies were performed in the remaining patients. The results of the diagnostic procedures were compared to the histology and the clinical course of the patients. The mean follow-up period was 12.5 months. RESULTS: A nodal metastasis was verified in 35% of all cases. Sensitivity of all imaging procedures including PET was 82%. Palpation had a sensitivity of only 61%. Specificity was 85% for ultrasound, 94% for CT and palpation, and 87% for PET. PET produced false negative results in 13.4% of all cases. Inflammation was detected in these cases. The positive predictive value was marginally better for PET than for ultrasound (77% vs. 75%). It proved to be lower than the values for palpation (86%) and CT (88%). Negative predictive value was 90-91% for all imaging procedures. CONCLUSION: In the primary diagnosis of nodal alterations in the head and neck region, a PET scan has the same diagnostic value as ultrasound or CT. By imaging the metabolism of a suspected nodal metastasis, PET can help to improve the assessment of regions with uncertain anatomic features. To avoid false positive results, acute and chronic inflammatory alterations have to be ruled out before the PET imaging.     

Usefulness of technetium-99m methoxyisobutylisonitrile single-photon emission computed tomography and computed tomography in the evaluation of cervical lymph node metastasis

The aim of this study was to compare the effectiveness of technetium-99m methoxyisobutylisonitrile ((99m)Tc-MIBI) single-photon emission computed tomography (SPECT) and computed tomography (CT) in evaluating cervical lymph node metastasis of head and neck cancer. Histopathologic results of 166 cervical lymph node levels in 31 neck-dissected patients were compared with pre-operative CT and (99m)Tc-MIBI SPECT findings about cervical lymph node metastasis, retrospectively. Sensitivity, specificity and predictability of CT and (99m)Tc-MIBI SPECT were 68.2, 93.1 and 89.8 per cent and 59.1, 87.5 and 83.7 per cent, respectively. When analysing CT and(99m)Tc-MIBI SPECT together, sensitivity and specificity were 86.4 and 99.3 per cent, respectively. The combined use of (99m)Tc-MIBI SPECT and CT could increase the accuracy of cervical lymph node metastases detection, compared with separate use of either (99m)Tc-MIBI SPECT or CT.     

Positron Emission Tomography in the Evaluation of the N0 Neck

The presence of cervical lymph node metastasis in patients with head and neck cancer is associated with an unfavorable prognosis. Reports vary as to whether various conventional radiographic studies, such as computed tomography (CT) and magnetic resonance imaging, confer an advantage over physical examination in the patient without clinical findings of cervical metastasis (N0). Positron emission tomography (PET) is a functional imaging modality that has recently been used for head and neck neoplasms. The use of PET in the evaluation of the N0-staged neck in 14 consecutive patients with squamous cell carcinoma (SCC) of the upper aerodigestive tract is reported. Seven patients (50%) undergoing 13 neck dissections had pathologic evidence of disease. PET scans were positive in five patients with pathologically confirmed cervical metastasis. PET scans were negative in seven patients (11 neck dissections) with no pathologic evidence of disease. PET scans were positive for unilateral cervical metastasis in two of three patients with involvement of a single lymph node. PET scans were positive in two of three patients with more than two lymph nodes involved. PET had an accuracy of 100% in the eight patients with SCC of the oral cavity. In patients with oropharyngeal or hypopharyngeal carcinoma PET localized cervical metastasis in two of four patients with neck metastasis. In the patient with an N0-staged neck on clinical examination, PET was found to have an overall sensitivity of 78%, specificity of 100%, positive predictive value of 100%, negative predictive value of 88%, and accuracy of 92%. CT demonstrated sensitivity of 57%, specificity of 90%, positive predictive value of 80%, negative predictive value of 75%, and accuracy of 76%. PET showed a trend in increased accuracy (P= 0.11) over CT. PET appears to be a promising diagnostic aid that may be applied when evaluating the N0-staged neck, especially for SCC of the oral cavity.     

Accuracy of computed tomography in determining the presence or absence of metastatic retropharyngeal adenopathy

OBJECTIVE: To decide the accuracy of computed tomography in determining the presence or absence of metastatic retropharygeal adenopathy in patients with squamous cell carcinoma of the head and neck. DESIGN: A comparison of the results of retrospective blinded review of preoperative computed tomographic scans with the histologic findings of retropharyngeal node dissection at the time of surgery. SETTING: Academic tertiary care center. PATIENTS: Twenty-six patients with advanced stage squamous cell carcinoma of the head and neck. MAIN OUTCOME MEASURES: Computed tomographic findings and histologic results of retropharyngeal node dissection. RESULTS: The retropharyngeal nodes were pathologically positive for metastasis in 6 (23%) of the 26 patients. The radiologist (J.M.T.) correctly read the scan in 3 of 6 patients with histologically proved metastasis, and in 14 of 20 patients with histologic features negative for metastasis. The sensitivity of the radiologist reading was 50%, and the specificity was 70%. The positive predictive value was 33%, and the negative predictive value was 82%. CONCLUSION: The presence of retropharyngeal node metastasis cannot be determined by computed tomographic imaging alone. Arch Otolaryngol Head Neck Surg. 2000;126:1478-1481     

High sensitivity and negative predictive value of sentinel lymph node biopsy in a retrospective early stage oral cavity cancer cohort in the Northern Netherlands

Objectives

In cT1‐2N0, oral squamous cell carcinoma (OSCC) occult metastases are detected in 23%‐37% of cases. Sentinel lymph node biopsy (SLNB) was introduced in head and neck cancer as a minimally invasive alternative for an elective neck dissection in neck staging. Meta‐analyses of SLNB accuracy show heterogeneity in the existing studies for reference standards, imaging techniques and pathological examination. The aim of this study was to assess the sensitivity and negative predictive value (NPV) of the SLNB in detecting occult metastases in cT1‐2N0 OSCC in a well‐defined cohort.

Design

Retrospective study. The SLNB procedure consisted of lymphoscintigraphy, SPECT/CT‐scanning and gamma probe detection. Routine follow‐up was the reference standard for the SLNB negative neck. Histopathological examination of sentinel lymph nodes (SLN) consisted of step serial sectioning, haematoxylin‐eosin and cytokeratin AE1/3 staining.

Setting

Two comprehensive oncology centres.

Participants

A total of 91 consecutive patients with primary cT1‐2N0 OSCC treated by primary resection and neck staging by SLNB procedure between 2008 and 2016.

Main outcome measures

Sensitivity and negative predictive value.

Results

In all cases, SLNs were harvested. A total of 25 (27%) patients had tumour‐positive SLNs. The median follow‐up was 32 months (range 2‐104). Four patients were diagnosed with an isolated regional recurrence in the SLNB negative neck side resulting in an 85% sensitivity and a 94% NPV.

Conclusion

In our cohort, the SLNB detected occult metastases in early OSCC with 85% sensitivity and 94% NPV. This supports that SLNB is a reliable procedure for surgical staging of the neck in case of oral cT1‐2N0 SCC.     

The role of computed tomography for localization of parathyroid adenomas

Objective/Hypothesis: The purpose of this study was to evaluate the use of computed tomography (CT) for localization of parathyroid adenomas (PA) when first‐line imaging is indeterminate. Study Design: Retrospective case series. Methods: A search of operating room and radiology records identified 223 surgical explorations for primary hyperparathyroidism. Adenoma locations on CT, ultrasound, and nuclear scintigraphy were correlated with an independent review of operative records. Results: The presence of adenoma in the correct side and quadrant of the neck was predicted by CT in 89% and 77% of studies, respectively. When first‐line studies were indeterminate, the positive predictive value of CT for localization of PA to the correct side and quadrant of the neck was 87% and 69%, respectively. Conclusions: When first‐line localization studies are indeterminate in patients with primary hyperparathyroidism, CT is a valuable, rapid, and widely available imaging modality that can be used to localize PA.     

Impact of [18F]-2-fluorodeoxyglucose-positron emission tomography/computed tomography on previously untreated head and neck cancer patients

OBJECTIVES: The role of fused modality [F]-2-fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT) in diagnosing and accurately staging patients with primary, metastatic, and recurrent head and neck (HN) cancer is evolving, and the clinical implications need to be further defined. A few retrospective studies have been performed, but adequate sample sizes are lacking because the number of HN cancer patients is relatively small. This study evaluates the positive predictive value (PPV), sensitivity, specificity, and accuracy of PET/CT in previously untreated HN cancer patients at a single tertiary care institution. The purpose of this study is to evaluate the role of this new technology in the management of previously untreated HN cancer patients. STUDY DESIGN: Retrospective cohort outcomes study at a tertiary National Cancer Institute Comprehensive Cancer Center. MATERIALS AND METHODS: Institutional review board exemption #4 (45 CFR 46.101 [4]) criteria were applied for and accepted by the office of responsible research practices at the Ohio State University College of Medicine. The authors identified 268 consecutive PET/CT examinations between March 2005 and January 2006 for HN cancer ordered by the two senior authors at the James Cancer Hospital and Solove Research Institute of the Ohio State University Medical Center. PET/CT examinations were interpreted by one of three neuroradiologists. PPV, sensitivity, specificity, accuracy, diagnostic upstaging, and treatment management changes were determined from subset analysis of 123 previously untreated patients with HN cancer. Synchronous lesions were detected in 10 patients with use of this modality. PET/CT was also used to help manage 22 patients with unknown primary HN cancer. The statistics were verified by comparing PET/CT results with surgical specimen histopathology. RESULTS:: PET/CT was true-positive in 82.9% (102/123), with a per patient PPV of 87.2% and a per lesion PPV of 89.4%. PET/CT was false-positive in 12.2% (15/123) of patients and had a false-positive rate of 8.3% when calculated per lesion. In 67 patients who underwent neck dissection, PET/CT had a PPV of 92.7%. The accuracy was 89.7% in 20 patients who had bilateral neck dissections. The unknown primary site was found in 72.7% (16/22) of patients with unknown primary HN cancer. Synchronous lesions were found in 8.1% of patients by PET/CT, with a PPV of 66.6%. Distant metastases were detected in 15.4% (19/123) of patients. Treatment was altered in 30.9% (38/123) of patients as a result of this imaging modality. CONCLUSIONS: The benefit of the PET/CT imaging modality resides in its fusion of anatomic detail of the HN region with the sensitivity of detecting tumors with increased metabolic activity at distant sites. Treatment was altered in 30.9% of our previously untreated HN cancer patients because of this imaging technique, with altered treatment including upstaging, diagnosing distant and unresectable disease, and working-up second primary malignancies. The false-positive findings did not result in additional morbidity to these patients. Although PET/CT is sensitive in detecting occult cervical nodal metastases, it does not yet have the ability to replace neck dissection as the diagnostic standard of care. This study supports the use of PET/CT in patients with newly diagnosed HN cancer because of its high PPV and superiority of detecting distant metastases and synchronous lesions.     

The role of positron emission tomography/computed tomography in the management of recurrent papillary thyroid carcinoma

OBJECTIVES/HYPOTHESIS: The aim of the study was to evaluate the role of combined positron emission tomography/computed tomography (PET/CT) fusion imaging in the detection and management of recurrent papillary thyroid cancer. STUDY DESIGN: A retrospective analysis of 33 patients with suspected recurrent papillary thyroid carcinoma who had undergone PET/CT was performed. PET/CT was compared with standard imaging techniques in each patient to determine whether PET/CT contributed to the therapeutic management plan. Histopathological findings were correlated to PET/CT in patients who underwent surgery. METHODS: The senior author reviewed the charts of 33 patients with recurrent papillary thyroid carcinoma to determine the impact PET/CT had on management. PET/CT was compared with conventional imaging results. In surgical patients, PET/CT was compared with histopathological findings to determine its sensitivity, specificity, accuracy, positive predictive value, and negative predictive value. RESULTS: In 67% of the cases (22 of 33), PET/CT supplied additional information that altered or confirmed the management plan. Twenty of 33 patients underwent surgery with 36 sites assessed by histopathological analysis. PET/CT correlated with histopathological findings in 25 of 36 distinct anatomical sites, with an accuracy of 70%. The sensitivity of PET/CT in identifying recurrence was found to be 66%, with a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 27%. CONCLUSION: Combined PET/CT fusion scanning was most useful in the detection and management of recurrent papillary thyroid cancer in patients who had average thyroglobulin levels greater than 10 ng/mL and when the tumor no longer concentrated radioactive iodine. In 100% of the cases in which PET/CT localized a region suspicious for malignancy, histopathological analysis confirmed the results. When PET/CT is positive, it is a powerful tool for predicting exact locations of recurrent papillary thyroid cancer, thus making it a reliable guide for surgical planning. PET/CT is a supplement to conventional imaging and fine-needle aspiration in the workup of recurrent papillary thyroid cancer. A negative finding on PET/CT is not sufficiently reliable to preclude further investigation and treatment.     

Correlation between computed tomography and bone single photon emission-computed tomography scintigraphy in patients with chronic rhinosinusitis

BACKGROUND: Computed tomography (CT) has been the imaging study of choicefor evaluating chronic rhinosinusitis (CRS). 99mTc-MDP bone single photon emission-computed tomography (SPECT) has proven useful at identifying inflammation of bone and its use in CRS has been discussed recently. No studies, however, have documented the correlation between these two imaging modalities in CRS. METHODS: A retrospective analysis was performed of 30 patients with CRS who underwent CT and SPECT scan of the paranasal sinuses. Increased radiotracer uptake during SPECT scan was compared with CT findings graded on the Lund-Mackay score (LMS). The findings of the two imaging modalities were compared and evaluated for standard correlative statistics for diagnostic tests. RESULTS: SPECT imaging was abnormal in 25/30 patients, and CT was abnormal in 27/30 patients. Correlation between the two was highest for the ethmoid sinuses at 73.3%. SPECT had a high positive predictive value for mucosal inflammation on CT of 84.1%. Approximately 25% of individual sinuses with a positive SPECT in patients without prior surgery were not positive in corresponding sinuses onl CT. There was a positive correlation between the LMS and the number of SPECT positive sinuses within the same patient (r = 0.486; p = 0.006). CONCLUSION: 99mTc-MDP SPECT scan in patients with CRS is shown to be a useful indicator of bone involvement. The relatively high rate of bone involvement in the absence of mucosal inflammation as seen in this study warrants additional research and the potential need for different therapies than are currently available.     

Head and neck computed tomography virtual endoscopy: evaluation of a new imaging technique.

OBJECTIVE: To evaluate a new radiographic imaging technique: computed tomography virtual endoscopy (CTVE) for head and neck tumors. STUDY DESIGN: Twenty-one patients presenting with head and neck masses who underwent axial computed tomography (CT) scan with contrast were evaluated by CTVE. Comparisons were made with video-recorded images and operative records to evaluate the potential utility of this new imaging technique. METHODS: Twenty-one patients with aerodigestive head and neck tumors were evaluated by CTVE. One patient had a nasal cylindrical cell papilloma; the remainder, squamous cell carcinomas distributed throughout the upper aerodigestive tract. Patients underwent complete head and neck examination, flexible laryngoscopy, axial CT with contrast, CTVE, and in most cases, operative endoscopy. Available clinical and radiographic evaluations were compared and correlated to CTVE findings. RESULTS: CTVE accurately demonstrated abnormalities caused by intraluminal tumor, but where there was apposition of normal tissue against tumor, inaccurate depictions of surface contour occurred. Contour resolution was limited, and mucosal irregularity could not be defined. There was very good overall correlation between virtual images, flexible laryngoscopic findings, rigid endoscopy, and operative evaluation in cases where oncological resections were performed. CTVE appears to be most accurate in evaluation of subglottic and nasopharyngeal anatomy in our series of patients. CONCLUSION: CTVE is a new radiographic technique that provides surface-contour details. The technique is undergoing rapid technical evolution, and although the image quality is limited in situations where there is apposition of tissue folds, there are a number of potential applications for this new imaging technique.     

Correlation of computed tomography,echo-planar diffusion-weighted magnetic resonance imaging and surgical outcomes in middle ear cholesteatoma

Conclusion: Echo-planar diffusion-weighted magnetic resonance imaging (DW MRI) is more reliable than high-resolution computed tomography (HRCT) in predicting the presence and localization of cholesteatoma before tympanomastoid surgery. Objectives: To evaluate the diagnostic accuracy of HRCT and echo-planar DW MRI in the detection and localization of cholesteatoma. Methods: Fifty-nine patients were prospectively included in this study. Patients with suspected primary cholesteatoma were evaluated by HRCT and echo-planar DW MRI before tympanomastoid surgery. Radiological findings were correlated with intraoperative findings. Results: HRCT and echo-planar DW MRI accurately predicted the presence or absence of cholesteatoma in 40/59 (67.8%) and 52/59 (88.1%) patients, respectively. The sensitivity, specificity, and positive and negative predictive values of HRCT were 68.97%, 66.67%, 66.67%, and 68.97%, respectively. However, sensitivity, specificity, and positive and negative predictive values of echo-planar DW MRI were 85.71%, 90.32%, 88.89%, and 87.50%, respectively.     

Ability of positron emission tomography to detect residual neck node disease in patients with head and neck squamous cell carcinoma after definitive chemoradiotherapy

OBJECTIVE: To report our experience using the neck examination, computed tomography (CT), and positron emission tomography (PET) to clinically evaluate node-positive patients with head and neck squamous cell cancer for residual neck node disease after definitive chemoradiotherapy. DESIGN: Retrospective review of all Cleveland Clinic patients with head and neck squamous cell cancer and N2 or N3 neck node involvement at presentation who were treated with definitive concurrent chemoradiotherapy and who underwent clinical restaging after treatment using the neck examination, CT, and PET. SETTING: Tertiary care referral institution. PATIENTS: Forty-eight patients with 72 positive necks at diagnosis were followed up for a median of 20 months. MAIN OUTCOME MEASURES: Palpable nodes on examination, nodes larger than 1 cm, nodes with central necrosis on CT, or any hypermetabolic lymph nodes on PET were considered clinical evidence of residual nodal disease. The true rate of pathologic involvement was determined by histologic examination after planned neck dissection or if regional recurrence developed. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated for all 3 clinical assessment tools. RESULTS: Planned neck dissection was performed in 33 necks and was positive for residual neck node disease in 5 necks. A delayed neck dissection was performed in 5 necks and was positive in 3 necks. The positive predictive value was low for all 3 clinical assessment tools. The addition of PET did not significantly improve the negative predictive value or positive predictive value of CT and the clinical examination. CONCLUSIONS: Residual neck node disease after definitive chemoradiotherapy was infrequent and was not well predicted by PET. A positive PET finding in this setting is of little utility. Although a negative PET finding was highly predictive for control of neck disease after chemoradiotherapy, it added little to the clinical neck examination and CT.     

Brain perfusion single photon emission computed tomography findings in patients with posttraumatic anosmia and comparison with radiological imaging

BACKGROUND: Different techniques in neuroimaging have been proposed for assessment of olfactory dysfunction but they are not without limitations. Recently, some studies showed the usefulness of single photon emission-computed tomography (SPECT) in evaluation of patients with posttraumatic anosmia. This study was designed to assess the possible diagnostic value of SPECT findings in patients with posttraumatic anosmia in comparison with magnetic resonance imaging (MRI)/CT imaging. METHODS: Sixteen patients who had head trauma and consequently anosmia, which was defined according to Cain's identification test, were included in this study. Two nonanosmic groups, traumatic patients and nontraumatic healthy individuals, were selected as control groups for this study. Qualitative and semiquantitative brain perfusion SPECT was performed by measuring the uptake ratio of the orbital frontal cortex to occipital pole in the sagittal projections (uptake index). All 16 target patients had a previous CT scan and/or MRI. Semiquantitative and qualitative brain perfusion SPECT were compared with radiological imaging. RESULTS: Semiquantitative assessment of brain perfusion SPECT revealed remarkable orbital frontal hypoperfusion as compared with two control groups. 87.5% of anosmic patients showed orbital frontal hypoperfusion (-2 SD below the lowest level in healthy controls). In addition, the semiquantitative SPECT method detected more orbitofrontal abnormality than the qualitative method or radiological imaging (MRI and/or CT). CONCLUSION: Findings suggest that by using SPECT, posttraumatic anosmia corresponds to the hypoperfusion in the orbital frontal cortex in a great number of patients. Because of its availability, rather low cost, technical ease, and possibility to obtain objective quantitative information, brain perfusion SPECT can be complementary to other diagnostic techniques in the evaluation of olfactory function, although additional neurophysiological and imaging studies are needed.     

The role of computed tomographic scans in the management of the N-positive neck in head and neck squamous cell carcinoma after chemoradiotherapy

OBJECTIVE: To determine the sensitivity and specificity of computed tomographic (CT) scanning in predicting residual cervical metastatic disease (N-positive neck) in patients undergoing curative radiotherapy and chemoradiotherapy for squamous cell carcinoma (SCC) of the upper aerodigestive tract. DESIGN: Retrospective case series (1995-2002) of patients undergoing radiotherapy and chemoradiotherapy for advanced head and neck SCC. METHODS: Study entry criteria included N-positive neck disease, a complete response to treatment at the primary tumor site, posttreatment CT scan, posttreatment neck dissection, and correlation of posttreatment CT scan with pathologic neck specimen. We calculated the sensitivity and specificity of the CT scan to predict the presence of residual cervical metastatic disease after curative radiotherapy and chemoradiotherapy. RESULTS: Forty-three patients (including 10 with bilateral N-positive necks) met the study criteria for analysis. Twenty (38%) of the 53 neck dissection specimens were positive for residual cervical metastatic disease. The sensitivity of the CT scan was 85%, while the specificity was only 24%. The positive predictive value of the CT scan was 40%. CONCLUSIONS: While the role of the posttreatment neck dissection remains controversial, the surgeon must rely on clinical examination and imaging studies. Our practice has been to perform planned staged neck dissections on all N2/N3 necks as well as N1 necks with an incomplete response to treatment. Based on our results, it appears that the CT scan technique lacks adequate sensitivity and specificity to reliably predict the presence of residual metastatic disease.     

The value of PET/CT to assess clinically negative necks

The aim was to evaluate the efficacy of [¹⁸F]-2-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) in evaluating metastasis of head and neck squamous cell carcinoma (HNSCC) to the cervical lymph nodes, with specific attention to the efficacy in regard to clinically negative necks. This was a retrospective review of 243 patients with HNSCC between years 2005 and 2007 treated at a comprehensive cancer care institution who underwent pre-operative PET/CT and neck dissection with either an N0 (112 patients) or N+ (131 patients) clinical nodal status. PET/CT findings were correlated with histopathological results of surgical specimens. A majority of the primary sites were oral cavity and oropharynx (70%), followed by larynx, unknown primary and hypopharynx. In the group of 112 patients who underwent 144 neck dissections with N0 nodal status, sensitivity, specificity, positive predictive value (PPV) and negative predictive (NPV) and accuracy were 57, 82, 59, 80 and 74%, respectively. In the group of 131 patients who underwent 169 neck dissections with N+ nodal status, sensitivity, specificity, PPV, NPV and accuracy were 93, 70, 96, 58 and 91%, respectively. PET/CT has a much reduced rate of efficacy for the clinically negative neck compared to the clinically positive neck. PET/CT in its current stage does not appear to offer an advantage in staging the clinically N0 neck due to high rates of false positives and negatives.     

The role of positron emission tomography with 18F-fluorodeoxyglucose in nodal staging of clinical and radiological N0 head and neck cancers

The objective of the study was to evaluate the impact of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) imaging on nodal staging for head and neck cancers. This was a retrospectively analyzed single institution study. The study population consisted of 36 patients with head and neck cancers who were evaluated with PET/CT and went on to neck dissection. All of them had clinically and radiographically negative neck (N₀) and each patient underwent PET/CT imaging before undergoing selective neck dissection for N₀ disease. Tissues were submitted for histopathologic examination and were oriented for the pathologist to permit correlation between the histopathologic findings and the imaging results. The sizes of the lymph nodes and the maximum standardized uptake values (SUV_max) measured from PET/CT images were compared with the histopathologic findings. All primary tumors were visualized with PET/CT. On histopathological examination, 19 patients had positive and 17 patients had negative lymph nodes. Receiver operating characteristic analyses were used to predict the optimal corrected SUV_max cutoffs; the optimal value was 2.95 for respective outcomes of lymph node involvement. This cutoff value yielded 84.2 % sensitivity and 76.5 % specificity for nodal-level staging. PET/CT proved to be accurate in 27 (75 %) patients and inaccurate in 9 (25 %) patients. PET/CT was a valuable tool to assess nodal stage of head and neck cancers, and should be considered before surgical treatment.     

Positron emission tomography with fluorodeoxyglucose for suspected head and neck tumor recurrence in the symptomatic patient

OBJECTIVE: To analyze the impact of positron emission tomography with fluorodeoxyglucose (FDG-PET) in the treatment of patients suspected of having head and neck cancer recurrence. STUDY DESIGN: Prospective and consecutive inclusion of 44 patients presenting with clinical symptoms suggestive of head and neck tumor recurrence. METHODS: FDG-PET was compared with combined computed tomography (CT) plus magnetic resonance imaging (MRI) procedures for the differential diagnosis between tumor recurrence and benign post-therapeutic changes. For FDG-PET, the potential additional value of semiquantitative indexes was studied. The impact on patient treatment (i.e., their ability to accurately select patients for panendoscopic exploration) was analyzed retrospectively for both CT+MRI and PET workups. RESULTS: The diagnostic accuracy was found higher for PET than for combined CT+MRI: sensitivity ranged from 96% to 73%, specificity from 61% to 50%, and accuracy from 81% to 64% for PET and CT+MRI, respectively. The accuracy of FDG-PET was the highest (94%) in patients included more than 12 weeks after the end of therapy. In 15 discordant cases, PET was correct in 11 and CT+MRI in 4. Patient selection for panendoscopic exploration and biopsy was correct in 79% and 50% of patients with FDG-PET and CT+MRI, respectively. Quantification of FDG uptake had no additional value over visual analysis alone, although we found that a SUVlbm (standardized uptake value corrected for lean body mass) threshold of 3 could be helpful in patients scanned less than 12 weeks after the end of therapy. CONCLUSION: FDG-PET has a major additional diagnostic value to CT+MRI for the evaluation of the symptomatic patient suspected of having head and neck cancer recurrence. PET could have a direct impact on management by correctly selecting patients in whom a panendoscopic exploration with biopsy is indicated.