Hilar Uptake Research Articles

P1.03-076 Nodal Staging of Patients with Pulmonary Malignancies - The Predictive Value of Different Patterns of Mediastinal 18FDG-PET Activity

In patients with pulmonary malignancies, 18FDG uptake in mediastinal nodes is a sensitive but non-specific indicator of metastatic disease. The pattern of tracer uptake may improve the predictability of such findings. To retrospectively i) compare 18FDG-PET scans and EBUS findings in patients with documented pulmonary malignancies; and, ii) compare the pattern of 18FDG uptake in mediastinal nodes in patients with / without documented mediastinal node metastases. 62 patients with documented pulmonary malignancies underwent 18FDG-PET scintigraphy followed by EBUS within the ensuing 3 weeks. One-two nodes were assessed in each patient, determined by 18FDG-PET findings and accessibility of the FDG-positive nodes. The mediastinal nodal status from each procedure was compared. EBUS resulted in mediastinal nodal status downgrading in 25 (40%) patients. No upgrading was noted. Downgrading most likely occurred when there several non-enlarged lymph nodes of similar 18FDG-avidity distributed randomly and bilaterally in the mediastinum, often with bilateral hilar uptake (17 of 25 patients). Further, only 2 of 19 patients exhibiting such a pattern of mediastinal tracer distribution were found to have lymph node metastases (10%), and both had metastatic disease elsewhere on the PET scan. 21 of 23 patients with positive EBUS findings demonstrated discrete 18FDG-avid lymph nodes ipsilaterally, with minimal-to-no 18FDG-avid nodes contralaterally. EBUS findings in 14 (23%) patients were inconclusive, despite multiple sampling. Enlarged, rounded lymph nodes with avid FDG uptake (SUV>4) were also more likely to harbor metastatic disease. Conversely, a Hounsfield unit of >55 was associated with benign disease. The pattern of mediastinal 18FDG uptake was highly predictive of metastatic disease, and may circumvent the need for EBUS evaluation. Prospective analysis of these parameters will be undertaken.

Incidence of sarcoid-like reaction demonstrated on 18F-FDG PET-CT in head and neck cancer patients

Results SLR was diagnosed in 8/308 (2.6%) HNC patients. Of which 3 had mediastinal nodal uptake only, 2 had bilateral hilar nodal uptake only and 3 had both mediastinal and hilar uptake. All the 8 patients had primary HNC and deep cervical lymphadenopathy but no distant metastases, hence misinterpretation of SLR would have upstaged as M1 (metastasis positive). 4 cases were identified on scan for restaging of suspected recurrence, and 4 were for primary tumour staging. The mean SUVmax of SLR was 6.9 (range 2.4-9.6), and the mean SLR nodal size was 1.6cm in short axis (range 0.6-2.4cm), with no significant difference compared to active nodal diseases (P=0.33 and 0.23). Conclusion SLR was seen in 2.6% of HNC patients at 18F-FDG PET-CT examinations. 18F-FDG PET-CT plays a significant role in the management of HNC, and it is important to be aware of a possibility of SLR in order to avoid false-positive interpretation of metastasis.

Sarcoid-like reaction to malignancy on whole-body integrated 18F-FDG PET/CT: prevalence and disease pattern

To evaluate the prevalence of sarcoid-like reaction to malignancy detected using integrated 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography and computed tomography (PET/CT) in patients undergoing staging or restaging of solid-organ malignancy. A systematic search was performed using the institutional radiology information system of 2048 consecutive PET/CT examinations performed in cancer patients at a tertiary-referral centre. Cases that were considered suspicious for sarcoid-like reaction were identified from the initial radiological report and were retrospectively reviewed by three experienced PET/CT reporters. Sarcoid-like reaction was initially suspected in 23 of the 2048 (1.1%) FDG PET/CT examinations, with the diagnosis confirmed histologically or by clinico-radiological follow-up in 13 of the 23 cases (57%). Sarcoid-like reaction was more commonly seen in patients undergoing FDG PET/CT for restaging of suspected recurrence rather than for primary tumour staging (77% versus 23%; p=0.05). The mean maximum standardized uptake value (SUV(max)) of confirmed hilar and mediastinal sarcoid-like reaction was 7.3 (range 3.1-13.6). Symmetric hilar uptake was demonstrated in 11 of the 13 (85%) and all 13 had additional mediastinal nodal uptake. Pulmonary uptake was seen in seven of the 13 cases (54%). Extra-thoracic involvement was present in eight of the 13 (61.5%), including nodal, splenic, and hepatic lesions. Sarcoid-like reaction was suspected in 1.1% of cancer patients at FDG PET/CT examination, with confirmation of the diagnosis in 0.6%. With the increasing use of FDG PET/CT in cancer patients, it is important to be aware of the prevalence of this uncommon, but important, disease entity and to consider this diagnosis in appropriate cases in order to avoid a false-positive interpretation of metastatic disease.

Löfgren’s syndrome revisited: a study of 186 patients

PURPOSE: To evaluate the clinical features, the results of noninvasive tests and biopsies, and the outcome of patients with Löfgren’s syndrome. SUBJECTS AND METHODS: Patients diagnosed as having Löfgren’s syndrome at a university hospital in Barcelona, Spain, from 1974 to 1996, were prospectively followed. Löfgren’s syndrome was defined as the association of erythema nodosum or periarticular ankle inflammation with unilateral or bilateral hilar or right paratracheal lymphadenopathy. RESULTS: Löfgren’s syndrome was diagnosed in 186 patients. The mean age was 37 ± 11 years, and 157 (85%) were women. In 91 patients (49%), symptoms started during the spring ( P <0.0001). Erythema nodosum, periarticular ankle inflammation, or both were present at onset in 173 patients (93%). At the time of diagnosis, 161 patients (87%) had no respiratory symptoms; 151 (81%) had stage I abnormalities on chest radiograph, 29 (16%) stage II, and 6 (3%) stage 0. Five percent of patients had decreased forced vital capacity, and 15% had decreased carbon monoxide diffusing capacity. Extrathoracic involvement was infrequent. Serum angiotensin-converting enzyme levels were increased in 50% of patients. Gallium-67 scans showed hilar uptake in all the studied patients, but it yielded useful additional diagnostic information only in those with normal chest radiographs or with unilateral hilar lymphadenopathy. The diagnosis was proven with biopsy results in 63% of patients. None of the patients without histologic confirmation were subsequently found to have a diagnosis other than sarcoidosis. In the 133 patients who were followed for a mean of almost 5 years, 11 (8%) continued to have active disease, and 8 (6%) had several recurrences between 18 months and 20 years after a complete resolution. A normal serum angiotensin-converting enzyme level at diagnosis was associated with disease resolution without recurrence. CONCLUSION: Löfgren’s syndrome is usually a self-limiting form of sarcoidosis. Histologic confirmation is not necessary in typical cases. In a small number of patients, the disease may remain active or recur long after its onset, although usually with mild organ dysfunction.

Pulsating mass at the sternum: A primary carcinoma of ectopic mediastinal thyroid

receptor scans. 5 False positive lung scans have also been noted to result from increased hilar uptake after an upper respiratory tract infection, external beam irradiation, bleomycin administration, or surgical treatment. 5 However, if interpreted in an appropriate clinical setting, somatostatin receptor scintigraphy may provide an accurate, noninvasive technique for the characterization of indeterminate pulmonary nodules as hormonally active and should be considered in the diagnostic evaluation of the patient with Cushing's syndrome.

Evaluation of hilar 67Ga-citrate uptake in bronchogenic carcinoma

We evaluated hilar uptake on 67Ga-citrate scintigraphy and correlated with hilar lymph node metastases in one-hundred seventeen cases (two-hundred thirty four hila) of bronchogenic carcinoma. Hilar uptake was classified into three grades independently on anterior and posterior chest views: no uptake (grade 0), uptake equal to that in the thoracic vertebrae (grade 1), uptake higher than that in the thoracic vertebrae (grade 2). If a summed grade of anterior and posterior view was larger than 3, hilar uptake was considered as positive. In forty-four cases (forty-nine hila) with hilar lymph node metastases, positive hilar uptake was found in ten cases (eleven hila), resulting in sensitivity of 22% based on cases and 23% based on hila. In seventy-three cases (one-hundred forty-six hila) without hilar lymph node metastases, positive hilar uptake was found in six cases (ten hila), resulting in specificity of 91% based on cases and 93% based on hila. In comparison to scintigraphic findings of unilaterally positive hilar uptake, findings of bilaterally positive hilar uptake showed significantly lower accuracy in determining presence of hilar lymph node metastases. No definite correlation between hilar uptake and histopathology or 67Ga-citrate uptake in a primary tumor was observed. The results indicate that usefulness of 67Ga-citrate scintigraphy is limited when evaluating hilar lymph node metastases in bronchogenic carcinoma.

Taches de Bougie

Posterior segment lesions, including taches de bougie, may be the presenting sign of sarcoidosis. In patients with unrecognized sarcoidosis, taches de bougie may be misinterpreted as the lesions of birdshot chorioretinopathy (BCR) or multifocal choroiditis (MFC). In a retrospective study, the authors identified 22 patients with taches de bougie and sarcoidosis. A tissue biopsy showed noncaseating granulomas in 17 patients. All available ophthalmic and medical records of these patients were reviewed. Two patterns of taches de bougie were observed. Sixteen patients (73%) had small, discrete white spots in the inferior or nasal periphery, indistinguishable from the lesions of MFC. In six patients (27%), larger, posterior, pale yellow-orange streaks developed that were identical to the lesions of BCR. Visual prognosis was better with posterior streaks. The chest x-ray was normal in 5 of 16 patients with peripheral spots and in 3 of 6 patients with posterior streaks. Serum angiotensin-converting enzyme was negative in 5 of 14 patients. Gallium scan showed increased hilar uptake in five patients, three of whom had a normal chest x-ray. Human lymphocyte antigen A29 was positive in one of nine patients. Sarcoidosis should be considered in patients with fundus findings that resemble BCR or MFC. Initial evaluation should include chest x-ray and testing the angiotensin-converting enzyme level. These test results may be negative in patients outside the 20- to 40-year age group for typical sarcoid. Further evaluation with nondirected conjunctival biopsy and whole-body gallium scan may be indicated in certain patients, including (1) those with BCR or MFC with normal chest x-ray and elevated angiotensin-converting enzyme level; (2) patients older than 50 years with MFC; or (3) human lymphocyte antigen A29-negative BCR.

Single-photon emission computed tomography quantitation of gallium citrate uptake for the differentiation of lymphoma from benign hilar uptake.

To assess the role of quantitative gallium citrate (Ga 67) single-photon emission computed tomography (SPECT) in differentiating lymphoma from benign hilar uptake, concentrations of Ga 67 in 29 sites of documented lymphoma and in 75 benign lesions were compared. One hundred seven thoracic Ga 67 SPECT studies obtained in 101 consecutive lymphoma patients were reviewed. Fifty-nine studies detected Ga 67 uptake in the hilar and or mediastinal regions. Forty-eight studies showed no such abnormality. The concentration of Ga 67 in the thoracic lesions was measured using a quantitative SPECT technique and its nature was determined by correlation with computed tomographic (CT) scans and follow-up evaluation of the sites. In 20 of 59 abnormal studies (34%), there was lymphoma in the hilar and or mediastinal regions. In the remaining 39 abnormal studies (66%), Ga 67 uptake was benign. There were 29 sites of lymphoma and 75 benign lesions. The concentration of Ga 67 in lymphoma was significantly higher than in benign hilar uptake (13.2 +/- 5.4 %ID/mL x 10(-3) v 5.6 +/- 1.5 % injected dose (ID)/mL x 10(-3); P < .001). A concentration value of 8.3 %ID/mL x 10(-3) was found to best separate lymphoma and benign uptake, with a sensitivity of 90%, a specificity of 93%, a positive predictive value of 84%, and a negative predictive value of 96%. Lymphoma and benign hilar uptake differ significantly in their concentration of Ga 67. The present study shows that quantitative Ga-67 SPECT reliably differentiates lymphoma and benign uptake.

Does gallium uptake in the pulmonary hila predict involvement by non-Hodgkinʼs lymphoma?

Summary 67Ga imaging of non-Hodgkin's lymphoma is useful for evaluating the presence of viable tumour in a residual mass after treatment. However, we have frequently seen gallium uptake in the pulmonary hila without other evidence of lymphoma. To study the significance of this finding, 79 patients with intermediate grade non-Hodgkin's lymphoma were reviewed. Thirty-seven (47%) had abnormal hilar gallium uptake. Twenty-three of these could be fully evaluated, and only five (22%) had hilar lymphoma. A pattern of bilateral, symmetric hilar uptake was seen in 19 patients, but only one had evidence of lymphoma. In 15 cases, this pattern was seen only on single photon emission computed tomography (SPECT). The aetiology of this uptake remains unknown. It is not treatment related, as 12 patients had hilar gallium uptake prior to chemotherapy. Unless confirmed by other methods, hilar gallium uptake should not be attributed to lymphoma, and should not influence patient management.

Does gallium uptake in the pulmonary hila predict involvement by non-Hodgkinʼs lymphoma?

Summary 67Ga imaging of non-Hodgkin's lymphoma is useful for evaluating the presence of viable tumour in a residual mass after treatment. However, we have frequently seen gallium uptake in the pulmonary hila without other evidence of lymphoma. To study the significance of this finding, 79 patients with intermediate grade non-Hodgkin's lymphoma were reviewed. Thirty-seven (47%) had abnormal hilar gallium uptake. Twenty-three of these could be fully evaluated, and only five (22%) had hilar lymphoma. A pattern of bilateral, symmetric hilar uptake was seen in 19 patients, but only one had evidence of lymphoma. In 15 cases, this pattern was seen only on single photon emission computed tomography (SPECT). The aetiology of this uptake remains unknown. It is not treatment related, as 12 patients had hilar gallium uptake prior to chemotherapy. Unless confirmed by other methods, hilar gallium uptake should not be attributed to lymphoma, and should not influence patient management.

41. Does gallium uptake in the pulmonary hila predict involvement by non-Hodgkins lymphoma?

67Ga imaging of non-Hodgkin's lymphoma is useful for evaluating the presence of viable tumour in a residual mass after treatment. However, we have frequently seen gallium uptake in the pulmonary hila without other evidence of lymphoma. To study the significance of this finding, 79 patients with intermediate grade non-Hodgkin's lymphoma were reviewed. Thirty-seven (47%) had abnormal hilar gallium uptake. Twenty-three of these could be fully evaluated, and only five (22%) had hilar lymphoma. A pattern of bilateral, symmetric hilar uptake was seen in 19 patients, but only one had evidence of lymphoma. In 15 cases, this pattern was seen only on single photon emission computed tomography (SPECT). The aetiology of this uptake remains unknown. It is not treatment related, as 12 patients had hilar gallium uptake prior to chemotherapy. Unless confirmed by other methods, hilar gallium uptake should not be attributed to lymphoma, and should not influence patient management.

Whole-body Gallium 67 Scans: Role in Diagnosis of Sarcoidosis

Early studies of 67gallium (67Ga) scanning in sarcoidosis focused on the lungs as a measure of disease activity, likelihood of progression, and the advisability of corticosteroid therapy. The predictive value of pulmonary uptake proved to be limited, but there has been renewed interest in 67Ga scanning as a diagnostic aid with special attention to characteristic extrapulmonary uptake patterns. Review of whole-body 67Ga scans in 172 patients with sarcoidosis, 21 with lymphoma, and 51 with other disorders demonstrated distinctive cranial, mediastinal, and hilar uptake patterns in sarcoidosis patients. Bilateral hilar uptake occurred in 81 sarcoidosis patients (47%) but in no lymphoma cases. Increased lacrimal and/or salivary gland uptake was observed in 47.5% but lacked specificity. Uptake in peripheral lymph nodes was infrequent in sarcoidosis (5%) but common in lymphoma (57%). 67Ga scans are especially valuable in patients with uveitis and liver granulomas whose chest radiographs are normal or equivocal. 67Ga scans, unnecessary in typical cases of sarcoidosis, have an important diagnostic role by reducing the need for invasive biopsy procedures in asymptomatic patients.

Course of chronic hilar sarcoidosis in relation to markers of granulomatous activity.

Studies of the course of sarcoidosis have emphasized that patients with hilar or mediastinal adenopathy usually recover within several years or develop dissemination to the lungs. Chronic hilar and mediastinal adenopathy persisting with little or no change for many decades is an important subgroup that has not received adequate attention. Twelve such patients have been studied. Seven remained asymptomatic, despite persistent adenopathy, for a mean period of 16 years; two with disfiguring facial sarcoids received corticosteroids for 18 and 27 years, respectively, and three patients after ten years of stable adenopathy developed pulmonary infiltrates. Tests performed on patients with hilar adenopathy to evaluate cellular activity after a mean interval of over 16 years included Kveim reaction (positive in nine of ten), serum angiotensin converting enzyme (elevated in eight of 12), and gallium-67 scanning (hilar uptake in all eight tested). Results were similar for patients who remained well and for those who had symptomatic or progressive disease, indicating that these parameters of granulomatous activity do not reflect the duration of the disease, its outcome, or the need for treatment.