Role of 18F-FDG PET in detecting primary site in the patient with primary unknown carcinoma

The aim of this study was to verify the effectiveness of positron emission tomography (PET) in detecting primary sites in carcinoma of unknown primary (CUP) patients. In this study, CUP represented a group of heterogeneous tumors that shared the clinical manifestation of metastatic carcinoma with no obvious primary site at the time of first diagnosis, which included clinical investigations, computed tomography, magnetic resonance imaging and panendoscopy. We reviewed the records of 24 patients with CUP between January 1995 and December 2009. The patients who demonstrated additional tracer uptake sites other than previously known metastatic lesions by PET scan were done direct biopsies for the sites of accumulation. Patients who had a negative PET scan or for whom the primary site could not be identified by direct biopsies underwent examination under anesthesia of the at-risk occult tumor sites. PET scan demonstrated focal accumulation suspicious for primary tumor in 12 (50.0%) of 24 patients: tonsil 5, nasopharynx 3, hypopharynx 1, tongue 1, larynx 1, and maxillary sinus 1. A subsequent biopsy of these sites revealed primary cancer in 9 (37.5%) of 24 patients: tonsil 5, nasopharynx 1, hypopharynx 1, tongue 1, and maxillary sinus 1. In the remaining three patients, no malignant cells were found by the biopsy of the accumulated area: nasopharynx 2, larynx 1. PET scans increase the yield of primary tumor by 37.5%. The sensitivity, specificity for PET scan were 80.8, 76.9%, respectively. PET scanning is useful in detecting primary cancer of CUP patients.     

Diagnosis and staging of head and neck cancer: a comparison of modern imaging modalities (positron emission tomography, computed tomography, color-coded duplex sonography) with panendoscopic and histopathologic findings

OBJECTIVE: To compare the clinical value of positron emission tomography (PET) using fludeoxyglucose F 18, computed tomography (CT), color-coded duplex sonography (CCDS), and panendoscopy in the detection and staging of head and neck cancer. DESIGN: Prospective nonrandomized controlled study. SETTING: Medical school. PATIENTS: Convenience sample of 50 patients with suspected primary or recurrent head and neck cancer. INTERVENTION: Biopsy, tumor surgery. MAIN OUTCOME MEASURES: Information of diagnostic procedures compared with histopathologic features. RESULTS: Both PET and panendoscopy had a sensitivity of 95% and 100% for detection of primary tumor or recurrent carcinomas, respectively. Specificity for PET and panendoscopy was 92% and 85% in primary tumors and 100% and 80% in recurrent carcinoma, respectively. Sensitivity of CCDS and CT was 74% and 68% in primary tumors and 67% and 63% in recurrent carcinomas, respectively. Specificity was 75% and 69% in primary tumors and 100% and 80% in recurrent neoplasms. When assessing neck nodes, all imaging procedures exhibited identical sensitivity (84%). Specificity was 90%, 96%, and 88% in PET, CT, and CCDS, respectively. In recurrent lymph node metastases, sensitivity was 100%, 67%, and 67% and specificity was 87%, 91%, and 87% for PET, CT, and CCDS, respectively. CONCLUSIONS: Positron emission tomography was the most reliable imaging procedure in the detection of primary tumor and recurrent carcinomas localized in the head and neck region. Owing to its limited anatomical depiction, it cannot as yet replace other diagnostic procedures in preoperative planning but does contribute valuable complementary diagnostic information. Computed tomograpy may have difficulties in identifying recurrent carcinomas. For routine diagnosis of nodal spread in the neck, CCDS is recommended. Panendoscopy is a valuable diagnostic procedure that can provide key information in cases of superficial mucosal tumor involvement. Arch Otolaryngol Head Neck Surg. 2000;126:1457-1461     

Utility of panendoscopy for the detection of unknown primary head and neck cancer in patients with a negative PET/CT scan

We conducted a retrospective review of the records of 23 patients who had been diagnosed with regionally metastatic head and neck squamous cell carcinoma from an unknown primary tumor. Our goal was to assess the utility of panendoscopy in locating the primary tumor in those patients whose positron-emission tomography/computed tomography (PET/CT) findings were negative. Overall, we found that PET/CT had correctly identified the unknown primary in 12 of the 23 patients (52%); panendoscopy confirmed this finding in all 12. Of the remaining 11 patients, however, panendoscopy located the primary tumor in only 1 (9%). In this era of cost containment and ongoing advances in imaging and transnasal esophagoscopy, it is important to revisit the workup of an unknown primary in patients with a negative PET/CT scan. There are various advantages and disadvantages to performing panendoscopy with biopsy in patients with an unknown primary and a negative PET/CT scan, but our results and the findings of others indicate that it will detect the primary in only about 10% of these cases. We recommend careful selection of patients who are to undergo panendoscopy for the routine workup of an unknown primary.     

Occult primary tumors of the head and neck: accuracy of thallium 201 single-photon emission computed tomography and computed tomography and/or magnetic resonance imaging

OBJECTIVE: To determine the accuracy of thallium 201 single-photon emission computed tomography (thallium SPECT) and computed tomography and/or magnetic resonance imaging (CT/MRI) in the detection of occult primary tumors of the head and neck. DESIGN: Study of diagnostic tests. SETTING: National Cancer Institute, Amsterdam, the Netherlands. PATIENTS AND METHODS: Thirty-two patients with a neck node metastasis of an epithelial tumor and negative findings by mirror examination at initial presentation were included in the study. Twenty-nine patients underwent thallium SPECT and CT/MRI before examination under general anesthesia (EUA). In 3 patients only thallium SPECT was performed before EUA. Histological confirmation of an occult primary tumor during EUA was used as the gold standard. Negative radiodiagnostic and nuclear findings in the upper aerodigestive tract in the presence of a primary carcinoma other than of the head and neck were interpreted as true-negative findings. RESULTS: For thallium SPECT the following results were recorded: sensitivity, 67%; specificity, 69%; accuracy, 69%; positive predictive value, 33%; and negative predictive value, 90%. In 1 patient, thallium whole body scan indicated a primary carcinoma beyond the mucosal lining of the upper aerodigestive tract. The CT/MRI results were as follows: sensitivity, 71%; specificity, 73%; accuracy, 72%; positive predictive value, 45%; and negative predictive value, 89%. CONCLUSIONS: Thallium SPECT and CT/MRI showed comparable results for detection of occult primary tumors of the head and neck. A potential advantage of thallium SPECT is that it allows total body screening.     

Impact of positron emission tomography on the initial staging and therapy in locoregional advanced squamous cell carcinoma of the head and neck

OBJECTIVE: To evaluate the impact of 18F-fluoro-deoxy-glucose positron emission tomography after standard diagnostic workup in patients with advanced head and neck squamous cell carcinoma on staging and radiation treatment planning. STUDY DESIGN: Prospective controlled study. METHODS: Forty-eight patients (42 men and 6 women; mean age, 61 y; age range, 35-85 y) with histologically confirmed, advanced-stage (any T, N> or =N2 or T> or =T3, any N) mucosal head and neck squamous cell carcinoma underwent positron emission tomography. The routine workup consisting of physical examination, panendoscopy, chest x-ray film, and contrast-enhanced high-resolution helical computed tomography scan (HRCT) was used for comparison. End points were the extent of lymph node disease, distant metastases, and second primary tumors. RESULTS: In 41 of 48 patients (85%) the lymph node findings between HRCT and positron emission tomography were concordant. In three patients positron emission tomography led to an upstaging of the tumor in its N category, and in four patients positron emission tomography underestimated lymph node involvement. Positron emission tomography revealed more difficulties in delineating lymph node metastases adjacent to the primary tumor than did HRCT, but was superior for the detection of distant and contralateral lymph node metastases. Positron emission tomography suggested distant metastatic lesions in 6 of 48 patients (13%). Cytological workup confirmed distant metastases in two (4%) and second primary tumors in another two patients (4%). Positron emission tomography results were false-positive in two (4%) patients because of inflammatory changes. CONCLUSIONS: Whole-body PET is able to assess lymph node involvement, distant metastases, and second primaries in a single study. Even after a routine clinical staging, positron emission tomography leads to a change of treatment in approximately 8% of patients.     

Diagnostic strategies in cervical carcinoma of an unknown primary (CUP)

In patients with cervical cancer of an unknown primary (CUP), no established concept exists for the necessary diagnostic procedures. In order to find the primary tumor, extensive diagnostic steps are generally recommended; however, they are often not performed consistently. In the current study, we consistently used a diagnostic algorithm and analyzed its consequences on patients' prognoses. We retrospectively studied 57 patients who were found to have a cervical metastasis of the upper- or midneck and an unknown primary tumor after routine examination of the head and neck region. Patients were analyzed for the value of applied diagnostic measures, tumor classification, survival rates and frequencies of subsequent lymph node or distant metastases after the initial treatment. Our results showed that a diagnostic algorithm (lymph node biopsy, rigid panendoscopy with systematic biopsies of suspect regions as well as blind biopsies of endoscopically inconspicuous regions, including the tongue base and nasopharynx and bilateral tonsillectomy) led to the detection of 14 occult oropharyngeal and 5 nasopharyngeal primary tumors in the patients. These tumors were primarily diagnosed as CUP. Oropharyngeal tumors either grew submucosally or were so small that only microscopic evaluation of the entire tonsil uncovered the tumor. Imaging procedures (X-ray, ultrasound, CT, MRT and FDG-PET) as well as gynecological, urological and gastroenterological consultations did not reveal the primary tumors in any of the cases. The 3-year survival rate for the patients with occult oropharyngeal primary tumors was 100% after treatment, while the patients in which our diagnostic schedule did not reveal a primary tumor showed a survival rate of 58%. The prognosis of all of the patients with cervical carcinoma metastasis was dependent on the initial nodal stage. Metachronous metastasis after completion of the initial treatment was prognostically infaust, while secondary detection of the primary tumor was worthwhile during follow-up as long as further treatment options were offered. The prognosis of patients with cervical carcinoma metastases of the upper- and midneck is much more favorable than that of patients with a CUP syndrome of other localizations. Identification of an occult pharyngeal tumor is prognostically relevant, since it opens up the possibility of specific locoregional treatment. In patients with cervical CUP, blind but systematic pharyngeal biopsies, including bilateral tonsillectomy, should be performed.     

Positron emission tomography: poor sensitivity for occult tonsillar cancer

PURPOSE: The aim of the study was to determine the sensitivity of preoperative positron emission tomography (PET) scans in the detection of primary tumors of the tonsils. MATERIALS AND METHODS: We conducted a retrospective review of 46 patients treated at a university medical center for occult tonsillar cancer during the years 2002 to 2004. We identified patients who underwent a preoperative PET scan to locate an unknown primary tumor. Fusion computed tomography with PET (PET/CT) was used to further delineate anatomic localization to the tonsil area. A positive PET/CT scan was defined as asymmetric increased tracer uptake in the tonsil and/or tonsillar fossa ipsilateral to the tonsillar cancer site when compared with the contralateral site. A negative PET/CT scan was defined as equivocal symmetric tracer uptake bilaterally. RESULTS: Of the 46 patients, 6 (13.0%) had pretreatment PET scans. Of these 6 patients, 16.7% (n = 1) had positive PET, 66.7% (n = 4) had negative PET, and 16.7% (n = 1) demonstrated increased tracer uptake in tonsils bilaterally greater on the side contralateral to the cancer. In this group, PET scans had a sensitivity of 0.167 and false-negative ratio of 0.667 for tonsillar cancer detection. CONCLUSIONS: Although the patient population in this study is small (n = 6), the findings suggest that PET/ CT scans may offer a low sensitivity in detection of primary tonsillar cancers. However, PET/CT scans still have a significant role in the detection of other unknown primary head and neck tumors. Technical reasons for this finding are discussed.     

Fluorodeoxyglucose positron emission tomography, a new technique for increasing the detection rate of coincident thyroid cancer in head and neck oncology

Clinically occult thyroid cancer is not uncommon and may occur in 1% to 10% of the population Since the first studies on the use of fluorodeoxyglucose positron emission tomography (FDG PET) in clinical oncology some reports have appeared on the detection of occult tumors using this imaging modality. According to these results, the number of patients with head and neck cancer and clinically occult coincident primary tumors at initial presentation may be expected to increase. In two of the four patients presented, the coincident tumor was detected with FDG PET. The possible role of this new imaging technique is discussed in correlation with treatment and clinical outcome. Received: 24 March 2000 / Accepted: 14 June 2000     

The role of tonsillectomy in the initial diagnostic work-up of head and neck squamous cell carcinoma of unknown primary

ObjectiveThe aim of the present study was to determine the value of tonsillectomy in the initial diagnostic work-up of head and neck squamous cell carcinoma of unknown primary (HNSCCUP).Material and methodsA single-center retrospective study (1999–2012) included 45 patients. All cases underwent physical examination, panendoscopy and contrast-enhanced neck and chest CT scan; 27 (60%) also underwent 18-FDG PET scan. Imaging was systematically performed before panendoscopy. In 34 cases (75%), histologic tonsil samples ipsilateral to the HNSCCUP were collected (28 tonsillectomies and 6 biopsies) during panendoscopy. Categoric variables were compared on Chi-square test.ResultsClinical examination and CT did not identify any primary tumor. In 13 cases (38%), invasive squamous cell carcinoma (SCC) was diagnosed on histological samples (12 tonsillectomies, 1 biopsy). For these 13 cases, lymph nodes were located in the upper or middle jugular group, and in 3 cases lymph nodes were cystic on CT scan. In 7 cases (26%), there was an abnormal tonsillar 18-FDG uptake ipsilateral to the cervical lymphadenopathy; tonsillectomy was performed, and SCC was found in 5 of these cases: i.e., 18-FDG PET showed sensitivity and specificity of respectively 55.5 and 88.8%.ConclusionTonsillectomy has a role in the initial diagnostic work-up of HNSCCUP. It is especially useful when lymph nodes are located in the upper and/or middle jugular group with a cystic aspect on CT.     

Fluorodeoxyglucose imaging using a coincidence gamma camera to detect head and neck squamous cell carcinoma and response to chemotherapy

This prospective study was performed to evaluate the ability of a dual-head gamma camera with fluorine-18 fluorodeoxyglucose coincidence detection emission tomography (FDG-CDET) to detect primary tumor and cervical lymph nodes in head and neck squamous cell carcinoma (HNSCC), and to show the response of the carcinoma to chemotherapy. The findings were compared with those of physical examination, computed tomography (CT), and histopathology, before treatment in 61 patients, and after induction chemotherapy in 34 of them. Before treatment, the primary was detected in 93%, 79%, and 95% of cases on panendoscopy, CT, and FDG-CDET, respectively. After chemotherapy, 34 patients were evaluable for response of the primary tumor. Surgical resection was performed in 23 of them: agreement with histopathologic results for response to treatment was 74%, 69%, and 78% for panendoscopy, CT, and FDG-CDET, respectively. No surgical resection was performed in 11 of the 34 patients, but biopsies were performed before radiotherapy, and their rates of agreement with histopathologic results for response to treatment were 75%, 75%, and 67% on panendoscopy, CT, and FDG-CDET, respectively. For cervical lymph nodes, 245 sites were resected in 41 patients, and FDG-CDET appeared competitive with CT in detecting metastatic neck disease, especially after neoadjuvant chemotherapy; the accuracy was 93%. These results demonstrated the ability of FDG-CDET to detect primary tumors and cervical lymph nodes in HNSCC and to show its response to chemotherapy, as compared to the ability of CT and panendoscopy. It may be a complementary tool to evaluate residual disease after induction chemotherapy, although higher sensitivity would be required for FDG-CDET to be considered as a staging modality.     

Diagnostic sensitivity of 18fluorodeoxyglucose positron emission tomography for detecting synchronous multiple primary cancers in head and neck cancer patients

We assessed the sensitivity of positron emission tomography (PET) for detecting synchronous multiple primary cancers, particularly synchronous esophageal cancers in head and neck cancer patients. We retrospectively reviewed 230 head and neck cancer patients. All the patients routinely underwent the following examinations: urinalysis, occult blood, tumor marker detection [squamous cell carcinoma (SCC), cytokeratin fragment (CYFRA), and carcinoembryonic antigen (CEA)], esophagogastroduodenoscopy, colonoscopy (when CEA was high or occult blood was positive), abdominal ultrasonography, plain chest computed tomography (CT), and PET. Bronchoscopy was performed when CT revealed lung shadow of central region. Synchronous multiple primary cancers were detected in 42 (18.2%) patients. The diagnostic sensitivity of PET for synchronous primary cancers was as follows: esophagus, 7.6% (1/13); stomach, 25.0% (2/8); lung, 66.7% (4/6); head and neck, 75.0% (3/4); colon, 0% (0/1); kidney, 0% (0/1); and subcutaneous, 100% (1/1). The sensitivity of PET for detecting synchronous esophageal cancers is low because these are early-stage cancers (almost stage 0–I). Therefore, it is necessary to perform esophagogastroduodenoscopy for detecting synchronous esophageal cancers. PET is an important additional tool for detecting synchronous multiple primary cancers because the diagnostic sensitivity of PET in synchronous head and neck cancer and lung cancer is high. But PET has the limitation of sensitivity for synchronous multiple primary cancers because the diagnostic sensitivity of PET in synchronous esophageal cancer is very low.     

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.     

A new paradigm for the diagnosis and management of unknown primary tumors of the head and neck: A role for transoral robotic surgery

Objectives/Hypothesis:

In 2% to 3% of patients with cancer metastatic to cervical lymph nodes, a primary tumor will not be found despite exhaustive diagnostic efforts. The treatment for these patients includes cervical lymphadenectomy followed by radiation to areas with increased risk of harboring a mucosal primary. Wide‐field radiation therapy increases the incidence of xerostomia and dysphagia. Localizing a primary tumor has thus both therapeutic and quality‐of‐life implications, allowing possible complete surgical excision, concentrated radiation therapy, and potential deintensification of adjuvant therapy. With improved visualization and freedom of motion, transoral robotic surgery (TORS) is an innovative surgical modality that allows resection of oropharyngeal subsites with minimal morbidity.

Study Design:

Retrospective chart review.

Methods:

Ten patients with unknown primary tumors of the head and neck were identified. All patients underwent a cervical biopsy, positron‐emission tomography/computed tomography, formal endoscopy, and bilateral tonsillectomy. When the initial endoscopy and biopsies did not localize a primary tumor, all patients underwent transoral robotic base of tongue resection.

Results:

Evaluation of the patients' oropharyngeal mucosa using the robot did not reveal an obvious lesion and no palpable tumors were appreciated in the resected specimens. In 9/10 (90%) patients, pathologic examination revealed invasive squamous cell carcinoma (SCCA) with a mean diameter of 0.9 cm.

Conclusions:

Unknown primary SCCA presents a diagnostic challenge to the head and neck surgeon. We present a small series of tumors that would have been treated as unknown primaries under traditional diagnostic and therapeutic algorithms. TORS base of tongue resection identified primary tumors in 90% patients with minimal morbidity. Laryngoscope, 2013     

The use of positron emission tomography for early detection of recurrent head and neck squamous cell carcinoma in postradiotherapy patients

Positron emission tomography (PET) has recently proved to be highly sensitive in detecting known extracranial head and neck squamous cell carcinomas when compared to computed tomography and magnetic resonance imaging (MRI). The ability of PET to detect early subclinical recurrent squamous cell malignancies in patients who received primary radiotherapy was evaluated. A new PET-MRI coregistration technique was used to determine precise anatomic tumor location, enabling directed biopsies to confirm the presence of malignancy, and to plan additional therapeutic strategies. Ten patients underwent PET evaluation with intravenous [¹⁸F]-fluorodeoxyglucose and received postradiotherapy MRI scans. In all cases, PET accurately detected the presence of recurrent disease despite negative or equivocal MRI scans and indeterminate clinical examinations. PET appears to be highly effective in detecting early recurrent head and neck squamous cell malignancies in postirradiated patients.     

Squamous cell carcinoma metastatic to the neck from an unknown head and neck primary site

Squamous cell carcinoma metastatic to the neck from an unknown head and neck primary site is relatively uncommon and presents a challenging diagnostic and therapeutic dilemma. Diagnostic evaluation includes fine-needle aspiration of the neck mass, chest roentgenography, computed tomography, and/or magnetic resonance imaging of the head and neck, followed by panendoscopy and biopsies. The primary tumor will be detected in approximately 40% of patients; approximately 80% of cancers are located in the base of the tongue or tonsillar fossa. Management options include treatment of the neck alone or both sides of the neck and the potential head and neck primary sites. The latter approach is associated with better long-term control above the clavicles. The 5-year survival rate is approximately 50% after treatment and is influenced by the extent of neck disease. In this article, we review the pertinent literature.     

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.     

正电子发射计算机断层-CT融合显像在头颈肿瘤中的诊断价值

目的探讨^18氟-脱氧葡萄糖(18-nuorinenuorodeoxyducose，^18F-FDG)正电子发射计算机断层显像(positron emission tomography，PET)-CT融合显像在头颈肿瘤的原发灶诊断、复发的检测和诊断分析未知原发肿瘤转移癌中的诊断价值。方法27例已确诊头颈部原发肿瘤或转移癌，进行^18F-FDGPET-CT全身显像，并与临床资料对照。结果鼻咽癌组治疗前4例PET-CT均查出原发灶，其中2例确诊有颈淋巴结转移，与病理检查结果一致。鼻咽癌放疗后12例中4例PET-CT检查鼻咽部及颈部淋巴结均为阴性表现，符合临床和病理诊断；2例放疗后原发灶复发经病理检查证实，其中1例查出颈部淋巴结及全身多处转移经随访证实；6例鼻咽原发灶PET-CT检查阴性表现．但4例颈部显示淋巴结转移经病理检查证实，2例肺部、纵隔等有转移灶未经病理检查证实。未知原发肿瘤颈淋巴转移组4例患者PET-CT均检出原发灶，3例病理检查证实，另1例未经病理检查证实。其他头颈肿瘤组7例治疗后患者中，2例患者无复发转移表现，5例不同部位肿瘤检出原发部位复发或颈淋巴结转移，有4例经病理检查证实，1例放弃治疗未经病理检查证实。结论^18F-FDGPFT-CT将PET提供的肿瘤代谢图像和CT提供的解剖图像结合，对头颈原发肿瘤诊断，检测治疗后肿瘤复发，不明原因转移癌原发灶的诊断及远处转移灶的诊断具有较大的临床价值。     

Screening for distant metastases before salvage surgery in patients with recurrent head and neck squamous cell carcinoma: a retrospective case series comparing thoraco-abdominal CT, positron emission tomography and abdominal ultrasound

Clin. Otolaryngol. 2012, 37 , 197–206 Objectives: To evaluate the role of 18‐fluoro‐deoxy‐d ‐glucose (FDG)‐positron emission tomography (PET) scan for detecting distant metastases in the preoperative assessment of patients with recurrent head and neck squamous cell carcinoma (HNSCC). Design: Retrospective study. Setting: University Teaching Hospital. Main outcome measures: Thirty‐seven consecutive patients who presented, between April 2008 and April 2010, a local and/or regional recurrence of head and neck squamous cell carcinoma after treatment with radio‐chemotherapy were studied. The work‐up included thoraco‐abdominal computed tomography (CT), fluoro‐deoxy‐d ‐glucose‐positron emission tomography scan and abdominal ultrasound. The imaging results, when positive, were compared to histology or cytology (conducted during targeted examinations, for example, fiberoptic oesophago‐gastro‐duodenal search, colonoscopy, bronchoscopy, liver biopsy) or targeted imaging examination (Abdominal MRI, sonography) combined with clinical follow‐up. All patients were followed‐up for at least 6 months. Positron emission tomography performances were then analysed and compared with those of conventional imaging for detecting distant metastases. Results: Among the 37 patients, 9 (24%) had visceral metastases. The sensitivity, specificity, positive predictive value and negative predictive value for detecting metastasis or second primary were, respectively, 100%, 94%, 86% and 100% for CT and 92%, 87%, 74% and 97% for positron emission tomography. Computed tomography and positron emission tomography were strictly concordant in 32/37 (86%) of cases. No false‐negative result was found for CT, while we found one case of false‐negative positron emission tomography. The number of false‐positive results was two for CT and four for positron emission tomography. Conclusions: From our study, positron emission tomography does not appear to offer a first‐choice technique for the detection of metastases before salvage surgery as CT detected all lesions visible on positron emission tomography.     

Diagnostic utility of positron emission tomography-computed tomography for predicting malignancy in cystic neck masses in adults

OBJECTIVES: Combined positron emission tomography and computed tomography (PET-CT) is used for the diagnostic evaluation and staging of squamous cell carcinoma of the head and neck (SCCHN). By superimposing anatomic localization of CT with the physiologic data of PET, occult primary and metastatic neoplasms might be identified. Because the diagnostic algorithm for cystic neck masses in adults often overlaps with the work-up of cancer of unknown primary site, we evaluated the utility of PET-CT scans to identify the presence of malignancy and the location of primary tumor. STUDY DESIGN: Single-institution retrospective case review series. METHODS: We reviewed the PET-CT imaging of cystic neck masses occurring in five patients over 40 years of age with significant risk factors for SCCHN and correlated this information with histopathology. RESULTS: In each patient in our series, the PET portion of a combined PET-CT was misleading, whereas the CT examination was more suggestive of the correct pathology. Ultimately, clinical judgment and endoscopic evaluation, guided by CT findings, were most valuable for distinguishing malignant versus benign processes and identifying the primary tumor sites. CONCLUSIONS: PET-CT may not be a reliable modality for identifying malignancy in adults with suspicious cystic neck masses. A thorough clinical evaluation by an experienced head and neck surgeon, in conjunction with contrast-enhanced CT, may be sufficient to facilitate the optimal management of such patients.     

A systematic review and meta‐analysis of the role of positron emission tomography in the follow up of head and neck squamous cell carcinoma following radiotherapy or chemoradiotherapy

Objectives: This review examines the effectiveness of positron emission tomography (PET) in the detection of recurrent or persistent head and neck squamous cell carcinoma after radiotherapy or chemoradiotherapy. Design: A systematic review and meta‐analysis of trials of PET for detecting residual/recurrent head and neck squamous cell carcinoma treated by radiotherapy or chemoradiotherapy. Trials were quality assessed using the Quality Assessment of Diagnostic Accuracy Studies tool for assessing diagnostic accuracy studies. Quantitative data were extracted and a bivariate random effects model used to calculate pooled sensitivity and specificity. Setting: Tertiary referral head and neck centre. Participants: Prospective and retrospective studies, excluding reviews, which included patients with head and neck squamous cell carcinoma who had fluorodeoxyglucose PET in the post‐treatment phase following primary treatment by radiotherapy or chemoradiotherapy. Main outcomes measures: Quality assessment, sensitivity, specificity, false positive rates, false negative rates, positive and negative predictive values. Results: Twenty‐seven of 1871 identified studies were eligible for inclusion. The pooled sensitivity and specificity of PET for detecting residual or recurrent head and neck squamous cell carcinoma were 94% [95% confidence interval (CI), 87–97%] and 82% (95% CI, 76–86%) respectively. Positive and negative predictive values were 75% (95% CI, 68–82%), and 95% (95% CI, 92–97%) respectively. Sensitivity was greater for scans performed 10 weeks or more after treatment. Conclusions: Positron emission tomography is highly accurate in this role. However it is less sensitive early after treatment and has poor anatomical detail. PET may reduce the requirement for check endoscopies and planned neck dissections. A protocol for its use in post‐treatment surveillance is proposed.