Gallium scintigraphy in patients with adult T-cell leukemia lymphoma

Gallium scintigraphy was evaluated in 25 patients with adult T-cell leukemia lymphoma (ATLL). Anterior and posterior images were obtained at 72 h after administration of 3 mCi 67Ga-citrate using a gamma camera (Maxi-Camera 400 T, General Electric Co.) with a medium energy standard parallel hole collimator. Abnormally high accumulations were observed in 17 out of 25 cases (superficial lymph node, 8; hilar and mediastinal lymph node, 7; paraaortic lymph node, 2; lung, 9; liver, 1; bone, 1). There were 10 malignant lesions detected by 67Ga scintigraphy in 9 out of 17 cases (superficial lymph node, 1; hilar and mediastinal lymph node, 6; paraaortic lymph node, 1; liver, 1; bone, 1). White blood cell count and serum LDH levels were raised in patients with abnormally high accumulations of 67Ga. In conclusion, 67Ga scintigraphy seemed to be a useful examination to detect malignant lesions in patients with ATLL.     

A <Superscript>18</Superscript>F-FDG-positive, <Superscript>67</Superscript>Ga-negative,and transferrin receptor expression-negative patient with diffuse large B-cell lymphoma

We recently experienced a case with uveitis suffering from fever of unknown origin suspected of being caused by sarcoidosis. Chest computed tomography showed right supraclavicular, bilateral mediastinal, and right hilar lymphadenopathy, and intensive abnormal uptake of 2-[¹⁸F]fluoro-2-deoxy-d-glucose (¹⁸F-FDG) was observed on positron emission tomography with ¹⁸F-FDG (FDG-PET). On the other hand, ⁶⁷Ga scintigraphy showed almost no abnormal findings. Histopathological examination revealed the lesion to be a diffuse large B-cell lymphoma (DLBCL), namely, an aggressive non-Hodgkin lymphoma from a right supraclavicular lymph node biopsy specimen. Additional immunohistochemical analysis showed the negative expression of transferrin receptor (TfR) on the formalin-fixed paraffin-embedded specimen. Although DLBCL is generally considered to be a ⁶⁷Ga-avid tumor, it does not always have a large number of TfRs and that leads to a discrepancy between the ⁶⁷Ga scintigraphy and FDG-PET findings. FDG-PET should be more appropriate for the initial staging of DLBCL than ⁶⁷Ga scintigraphy, whereas ⁶⁷Ga scintigraphy might be able to provide additional information including prognostic factors and to support strategies that target TfR for cancer therapy.     

Lymphoscintigraphy by SC injection of 67Ga-citrate

Lymphoscintigraphy with SC injection of ⁶⁷Ga-citrate was carried out on patients with lymph node metastasis and malignant lymphoma. The dose given at each injection site was about 200 Ci and scintigraphy was started about 5 min after injection. Metastatic lymph nodes and malignant lymphoma were successfully imaged. This positive delineation corresponded well to cold lesions detected by lymphoscintigraphy with ^99mTc-rhenium colloid in metastatic lymph nodes. Hotter lesions in malignant lymphoma were scanned positively with ^99mTc-rhenium colloid by this method. In in vitro studies, incorporation of ⁶⁷Ga-citrate in HeLa S3 cells was about 4 times that in macrophages, when the incubation time was 1 h, while colloidal uptake by macrophages was 13 times that by HeLa S3 cells. The binding of ⁶⁷Ga to transferrin in lymph and pinocytosis are suggested mechanisms of localization. A combination of colloid-and sc ⁶⁷Ga-lymphoscintigraphy would be of value in the diagnosis of lymph node disease.     

Detection of bone marrow and extramedullary involvement in patients with non-Hodgkin’s lymphoma by whole-body MRI: comparison with bone and <Superscript>67</Superscript>Ga scintigraphies

The aim of this study was to evaluate the diagnostic potential of whole-body MRI (WB-MRI) for the detection of bone marrow and extramedullary involvement in patients with non-Hodgkins lymphoma. WB-MRI, which was performed on 34 patients, consisted of the recording of T1-weighted spin-echo images and a fast STIR sequence covering the entire skeleton. The WB-MRI findings for bone marrow and extramedullary involvement were compared with those from ⁶⁷Ga and bone scintigraphies and bone marrow biopsy results. Two MRI specialists reviewed the WB-MRI results and two expert radiologists in the field of nuclear medicine reviewed the bone and ⁶⁷Ga scintigraphy findings. Bone marrow and extramedullary involvement of non-Hodgkins lymphoma were confirmed by follow-up radiographs and CT and/or a histological biopsy. The detection rate of WB-MRI was high. More bone marrow involvement was detected by biopsy, and more lesions were detected by scintigraphies. In total, 89 lesions were detected by WB-MRI, whereas 15 were found by biopsy, 5 by ⁶⁷Ga scintigraphy, and 14 by bone scintigraphy. WB-MRI could also detect more extramedullary lesions than ⁶⁷Ga scintigraphy; i.e., 72 lesions were detected by WB-MRI, whereas 54 were discovered by ⁶⁷Ga scintigraphy. WB-MRI is useful for evaluating the involvement of bone marrow and extramedullary lesions throughout the skeleton in patients with non-Hodgkins lymphoma.     

Noninvasive staging of lung cancer. Indications and limitations of gallium-67 citrate imaging

The results of evaluation of the hila and mediastinum with 67Ga scans are contradictory, as are the recommendations by different investigators on the use of 67Ga scintigraphy in the clinical evaluation of patients with primary lung carcinoma. Nevertheless, the economy and logistic simplicity of evaluating local and distant metastases with a single imaging procedure are attractive, especially because the symptoms may not enable the physician to make a correct identification of the organ systems affected by metastases. Neumann and Hoffer state that "at present conventional Ga-67 scanning techniques cannot be recommended for preoperative staging of mediastinal lymph node metastases in lung cancer patients." According to Waxman, 67Ga scintigraphy, relative to other imaging modalities, is a sensitive indicator of hilar spread of a tumor. However, because of the normally high background activity within the sternum and spine, mediastinal abnormalities may be poorly detected. Since most pulmonary tumors metastasize via regional nodes to the pulmonary hilum and then to the mediastinum, the high sensitivity for the detection of pulmonary hilar abnormalities and the high specificity for detection of mediastinal lesions suggest that gallium scintigraphy is a valuable adjunctive test when used appropriately. The results obtained locally are probably the best guide for individual physicians in the selection of diagnostic tests for their patients. Gallium scans may thus be helpful in the clinical evaluation of patients with lung cancer. Although gallium scans identify mediastinal node involvement, there is considerable controversy over the relationship between the sensitivity and specificity of the method. By detecting distant extrathoracic metastases, the 67Ga scan may identify a small group of patients who can be spared a needless operation. Gallium scanning fails specifically for metastases within the brain; thus, it does not supplant CT scans of the brain and it is less sensitive than bone scans in detecting osseous metastases. Gallium scanning of patients with small-cell lung cancer is not useful in the selection of therapy but does become important from a prognostic standpoint. Patients with extrathoracic involvement by small-cell carcinoma of the lung are known to have limited survival times compared with those of patients with thoracic involvement alone. In identifying patients with extensive disease, the oncologist is thus provided with prognostic information that may be useful in the counseling of the patient and the patient's family.     

不同图像采集和处理对^67Ga显像质量及病灶探查的影响

目的分析平面显像、非衰减校正（NAC）断层显像和CT衰减校正（AC）断层显像等^67Ga显像图像采集和处理模式对图像质量和病灶判断的影响。方法用美国GE Millennium^TM VG 5型SPECT／CT仪对31例活动期肺结节病患者行^67Ga平面显像、胸部NAC断层显像;并对断层图像行CTAC。图像分析：双盲法阅片,判断平面图像、AC和NAC断层图像的图像质量及病灶数;测量病变与周围正常组织的放射性计数,并测量其比值。采用SPSS10．0软件,行配对t检验和,检验。结果图像质量按照平面显像、NAC、AC顺序依次提高（χ^2=25．880,P〈0．001）。以活动期结节病患者SPECT／CT示放射性增高的肺门、纵隔淋巴结为“病灶”,平面显像发现“病灶”70个,漏诊“病灶”8个;NAC、AC断层图像均发现“病灶”78个。NAC图像中“病灶”的放射性计数明显低于AC图像中“病灶”的放射性计数（15．240±8．865和67．241±35．049,t=-17．230,P〈0．001）。和NAC图像比较,AC图像“病灶”与肺的放射性比值增高（t=-7．520,P〈0．001）,“病灶”与肝（t=3．298,P=0．001）及“病灶”与腰椎（t=7,032,P〈0．001）的比值降低。结论^67Ga平面显像因前后组织放射性分布叠加,可能导致漏诊。^67Ga NAC断层显像能够较为准确地确定病变淋巴结的三维位置,但图像计数率低、噪声较大。AC断层图像虽未能增加检出的病灶数,但能有效提高NAC计数率,改善图像质量。     

Comparison of magnetic resonance imaging and 67gallium scintigraphy in the evaluation of posttherapeutic residual mediastinal mass in the patients with Hodgkin's lymphoma

IntroductionDetection of residual disease following the completion of primary treatment in Hodgkin's lymphoma (HL) patients diagnosed with mediastinal tumor mass has an exceptional importance in the assessment of therapeutic response. Magnetic resonance imaging (MRI) and ⁶⁷gallium (⁶⁷Ga) scintigraphy can be used to identify active tumor tissue in the mediastinal residuum.AimsTo evaluate: the accuracy of MRI and ⁶⁷Ga scintigraphy in the prediction of clinical HL relapse/progression; congruence of findings and the probability of mediastinal disease relapse/progression regarding to the detection of active/inactive tissue by both imaging methods.Materials and methodsThirty HL patients with abnormal mediastinal tissue following the completion of primary treatment were examined by MRI and ⁶⁷Ga scintigraphy. Positive findings were: high signal intensity on unenhanced T2-weighted images on MRI and the abnormal accumulation of gallium on scintigraphy or SPECT. These findings were compared with the clinical follow-up.ResultsSensitivity, specificity, accuracy, positive and negative predictive values were: 75.0%, 96.2%, 93.3%, 75.0%, 96.2% in MRI and 50.0%, 88.5%, 83.3%, 40.0%, 92.0% in ⁶⁷Ga scintigraphy. Discrepant results concerning the mediastinal tissue activity were found in 3 of 30 patients (10%). No statistically significant differences were found between both imaging methods in sensitivity, specificity and accuracy. Estimated 2-years progression free survival (PFS) for patients without and with active residual mediastinal tissue by MRI was 96% and 25% (p = 0.0001), respectively. The probability of 2-years PFS in the cases with negative and positive findings on ⁶⁷Ga scintigraphy was 92% and 60% (p = 0.026), respectively.ConclusionAlthough MRI showed better results than ⁶⁷Ga scintigraphy in the assessment of residual mediastinal tissue activity in HL patients after primary treatment, the difference between these methods was not statistically significant. Both methods could be included in the standard restaging protocol.     

Clinical relevance of gallium-67 scintigraphy in lymphoma before and after therapy

The clinical impact of gallium-67 scintigraphy before and after therapy for lymphoma remains controversial. The aims of this study were: (1) to compare the staging of lymphoma by ⁶⁷Ga scintigraphy only with staging by clinical examination and conventional imaging (CI), and (2) to analyse the clinical relevance of both ⁶⁷Ga imaging and CI after treatment. From March 1995 to November 1998, 86 ⁶⁷Ga scintigraphy studies were performed in 62 patients with Hodgkin’s disease (n=52) or non-Hodgkin’s lymphoma (n=10). ⁶⁷Ga scintigraphy was performed at diagnosis (n=44) or after therapy (n=42) using 185–220 MBq ⁶⁷Ga citrate and planar and single-photon emission tomography (SPET) studies. Treatment comprised radiotherapy, chemotherapy or combined modalities. CI included plain chest radiography, computed tomography (CT) of the chest and abdomen/pelvis, ultrasound of the abdomen, lymphography, bone marrow biopsy and, when necessary, magnetic resonance imaging (MRI) and bone scintigraphy. For individual suspected sites of disease before treatment, complete agreement between clinical examination and CI on the one hand and ⁶⁷Ga scintigraphy on the other hand was observed in 25/44 patients (57%; 95% confidence interval 41%–72%). Clinical examination and CI showed more sites than did ⁶⁷Ga scintigraphy in 12/44 patients (27%) and ⁶⁷Ga imaging demonstrated more sites than CI in 6/44 patients (11%). The clinical stage of the disease as assessed using ⁶⁷Ga scintigraphy only was in agreement with that using all diagnostic procedures in 34/44 patients (77%; 95% confidence interval 62%–89%). Compared with CI staging, ⁶⁷Ga scintigraphy downstaged seven patients (16%) and upstaged three (7%). ⁶⁷Ga scintigraphy downstaged mainly because of the limited value of the technique below the diaphragm and upstaged owing to the good sensitivity in the lung. After therapy, both CI and ⁶⁷Ga scintigraphy were normal in 11 patients. All but one of these patients were in complete remission after a median follow-up of 31 months. In contrast, radiological residual mass was observed in 31/42 patients. ⁶⁷Ga imaging was normal in 22/31 (71%); 17 of these 22 patients, including nine with a large residual mass (≥2 cm), were in complete remission after a median follow-up of 32 months, while four suffered relapses 8–45 months later. The cause of death remained unknown in one patient. ⁶⁷Ga scintigraphy showed abnormal uptake in 9 of the 31 patients with a large residual mass. Active disease was demonstrated in eight patients and one patient was in complete remission 30 months thereafter. Our data show that ⁶⁷Ga imaging cannot replace CI in initial staging but can demonstrate additional individual sites of disease in more than 10% of patients and can lead to clinical upstaging with potential prognostic and therapeutic consequences. After therapy, ⁶⁷Ga scintigraphy has a clinical impact when radiological abnormalities persist because it can either avoid unnecessary complementary treatment or confirm the need to change treatment modalities. Received 5 July and in revised form 9 September 1999     

Retrospective review: usefulness of a number of imaging modalities including CT, MRI, technetium-99m pertechnetate scintigraphy, gallium-67 scintigraphy and F-18-FDG PET in the differentiation of benign from malignant parotid masses

Objective The aim of this study is to evaluate an imaging approach using computed tomography (CT), magnetic resonance imaging (MRI), technetium-99m pertechnetate scintigraphy (^99mTc pertechnetate scintigraphy), gallium-67 scintigraphy (⁶⁷Ga scintigraphy) and fluorine-18 fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET). Material and Methods We reviewed retrospectively 59 patients with parotid masses. CT, MRI,⁶⁷Ga scintigraphy,^99mTc pertechnetate scintigraphy, and¹⁸F-FDG PET were performed. Results All of the benign tumors had smooth margins on CT and MRI. Patients with inflammatory lesions and malignant lesions showed well-defined margins or ill-defined margins. All Warthin's tumors showed high technetium accumulation. Many of malignant tumors showed high FDG accumulation. Both pleomorphic adenomas and Warthin's tumors showed high accumulation in some cases on¹⁸F-FDG PET. Among 15 patients with pleomorphic adenoma, 14 patients showed marked hyperintensity relative to CSF on T2-weighted images and partial enhancement on contrast-enhanced T1-weighted images. Combination of several imaging modarity offered usefulness of differential diagnosis for parotid masses. Conclusion An efficient combination of imaging methods may be helpul for achieve the correct diagnosis.     

Detection of metastatic lesions from malignant pheochromocytoma and paraganglioma with diffusion-weighted magnetic resonance imaging: comparison with 18F-FDG positron emission tomography and 123I-MIBG scintigraphy

OBJECTIVE: To investigate the diagnostic features of whole-body diffusion-weighted magnetic resonance imaging (DWI) as compared with 2-[(18)F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) and (123)I-meta-iodo-benzyl guanidine scintigraphy (MIBG) on metastatic lesions of patients with malignant pheochromocytoma or paraganglioma. METHODS: We prospectively studied 11 patients with histologically confirmed pheochromocytoma/paraganglioma and possible metastatic lesions. FDG-PET, MIBG, and DWI examinations were performed within 1 week, and the images were visually interpreted. Abnormal positive uptake either on MIBG or on FDG-PET was considered as metastases. Abnormal high signal intensities on DWI were considered as metastases using conventional T1-and T2-weighted images as reference. RESULTS: FDG-PET and DWI demonstrated metastatic lesions in all 11 patients, but MIBG showed no metastatic lesions in two patients. The numbers of lymph node metastases depicted on FDG-PET, MIBG, and DWI were 19, 6, and 39; bone metastases were 50, 49, and 60; liver metastases were 9, 9, and 15; lung metastases were 5, 7, and 5, respectively. MIBG failed to demonstrate many metastatic lesions, which were demonstrated on FDG-PET or DWI, although two mediastinal lymph node metastases, three lung metastases, and six bone metastases, which were not seen on DWI, were clearly demonstrated on MIBG. DWI showed 15 liver metastases, but 6 of them were not seen on FDG-PET or MIBG. CONCLUSIONS: DWI may be particularly advantageous in depicting lymph node and liver metastases and may have a higher rate of detecting metastatic lesions when compared with MIBG or FDG-PET. The limitations of DWI were possible false-positive finding, and probable lower detectability of mediastinal lymph node and lung metastasis.     

Usefulness of gallium 67 in research into the need for radical cervical lymph node dissection in patients with head and neck carcinomas

Fifty-nine patients with head and neck carcinoma were examined with 67Ga scintigraphy. All patients had undergone lymph node dissection of the neck. They were followed for a minimum of 2 years after the examination. The primary tumor, treated prior/contemporaneously to the lymph node dissection, did not evolve in this interval. Metastatic involvement of the lymph node capsule was observed in all 44 cases with metastatic lymph nodes; macroscopic radicality was surgically obtained since involvement of the capsule was only microscopic. Nevertheless, complementary radiotherapy was given. The whole of 17 recurrences in the soft tissues of the neck were found, within 2 years, in the group of 26 patients who had undergone dissection of lymph nodes with metastatic capsular involvement and whose postoperative 67Ga scintigraphy was positive. On the contrary, no recurrences in the soft tissues of the neck were observed in the group of 18 patients who had undergone dissection of lymph nodes with metastatic capsular involvement and whose scintigraphy was negative. This result proves (P less than 0.001) 67Ga capable of evidencing eventual microscopic diffusion. Such a possibility has not yet been realized in vivo with any other investigation technique. Scintigraphy was negative in a control group of 15 patients who had undergone lymph node dissection, and with nonmetastatic lymph nodes. This finding leads us to exclude that the use of 67Ga might result in misinterpreted findings in the exploration of relatively superficial tissues. In fact, the eventual accumulation of radioisotope in nonneoplastic pathologies is quite easily recognizable in the neck. We can therefore conclude that in those 9 cases with positive scintigraphy and in whom no recurrence was found, microscopic diffusion was probably present, but local recurrence of the disease was prevented by complementary radiotherapy.     

Gallium-67 imaging in the diagnosis of blastomycosis

⁶⁷Ga imaging was used in a group of 13 untreated patients with documented South American blastomycosis in an attempt to obtain additional information on the site and extent of the lesions. All diagnoses were confirmed by demonstration of the fungi in the lesions or body fluids. Serologic tests were performed on all patients. ⁶⁷Ga imaging was correlated with X-ray in all patients, and with bone imaging when bony lesions were suspected. ⁶⁷Ga imaging was positive for all lesions detected on chest X-ray and by clinical evaluation. More importantly, lesions clinically unsuspected and missed by other diagnostic techniques were shown on ⁶⁷Ga imaging: bony and hepatic lesions in three patients; a brain lesion in one patient and parotid gland involvement in five patients. There was good agreement between ⁶⁷Ga imaging and clinical and laboratory data, scintigraphy being more sensitive. Follow-up studies after specific therapy demonstrated decreased uptake in the lungs and other sites. ⁶⁷Ga imaging is a useful tool for detection of suspected and unsuspected lesions of blastomycosis and to evaluate the response of the disease to specific therapy.     

Identification of AIDS-related tuberculosis with concordant gallium-67 and three-hour delayed thallium-201 scintigraphy

Concordant gallium-67 and thallium-201 uptake has been described in malignant lesions. More recently,²⁰¹Tl accumulation has been described in some benign conditions. The authors report three HIV-positive patients who underwent⁶⁷Ga and²⁰¹Tl scintigraphy. These studies revealed concordant⁶⁷Ga and²⁰¹Tl uptake and tumour was erroneously diagnosed. All three patients were finally diagnosed as having tuberculosis.     

Staging and monitoring of malignant lymphoma of the bone: comparison of 67Ga scintigraphy and MRI.

The aim of this study was two-fold: to compare 67Ga scintigraphy with MRI (a) for the staging of malignant lymphoma of the bone and (b) with regard to accuracy in detecting residual disease after first-line chemotherapy for restaging. METHODS: Twenty-one patients with 36 malignant osseous lesions were examined, including 7 patients with primary or multifocal osseous lymphoma and 14 patients with malignant lymphoma and simultaneous or secondary involvement of the bone. After first-line therapy, MRI and 67Ga scintigraphy were performed on 13 patients. The remission status based on all clinical and radiological findings during the follow-up was used as the gold standard. RESULTS: The osseous lesions were located on the axial skeleton in 64% of patients and on the appendicular skeleton in 36%. 67Ga scintigraphy detected 77% of the osseous lesions examined by MRI. For restaging after first-line therapy, MRI had a sensitivity of 90% and a specificity of 80% when dynamic MRI information was included. There were several false-positive results as a result of the pathologic increase in signal intensity ratios of reactive hematopoietic regions after chemotherapy. For 67Ga scintigraphy, a sensitivity of 70% and a specificity of 93% were calculated. CONCLUSION: These data show that monitoring malignant lymphoma of the bone still presents diagnostic problems. Given the high sensitivity of MRI and the high specificity of 67Ga scintigraphy but the limited specificity of MRI and sensitivity of 67Ga scintigraphy, both methods are valuable but should be used as complementary diagnostic tools.     

Limited value of fluorine-18 fluorodeoxyglucose positron emission tomography for the imaging of neuroendocrine tumours

Scintigraphy using [¹¹¹In-DTPA-d-Phe¹]-pentetreotide or pentavalent technetium-99m-dimercaptosuccinic acid [^99mTc(V)-DMSA] has been shown to localize well-differentiated and slowly growing neuroendocrine tumours, whereas increased fluorodeoxyglucose (FDG) uptake is associated with malignancy. The aim of this study was to compare the value of fluorine-18 FDG positron emission tomography (PET) with that of somatostatin receptor scintigraphy (SS-R) and dual-radionuclide scintigraphy [SS-R and ^99mTc(V)-DMSA = DNS] in detecting malignant neuroendocrine tumours. Fifteen patients with metastasizing gastroenteropancreatic tumours (GEP tumours; n = 7), medullary thyroid carcinomas (MTCs; n = 8) and elevated tumour markers [GEP tumours: 5-hydroxyindoleacetic acid, insulin; MTCs: calcitonin, carcinoembryonic antigen (CEA)] were studied. Prior to PET, all patients with GEP tumours underwent SS-R. DNS was performed in all patients with MTC. Patients had been fasting for at least 12 h and normal glucose plasma levels were confirmed. Sixty minutes after intravenous administration of ¹⁸F-FDG (mean: 374 MBq) whole-body PET and regional scans were performed. In addition, the resected tissues were prepared for immunocytochemistry examination (cell cycle-associated Ki-67 antigen). In two patients with less-differentiated GEP tumours associated with high proliferative activity and increased FDG uptake, SS-R failed to detect any lesion. In comparison, in four patients with well-differentiated GEP tumours showing low proliferative acitivity, SS-R localized four primary tumours, 22 lymph node metastases and 18 malignant liver lesions, whereas ¹⁸F-FDG PET demonstrated normal distribution. In one patient with a metastasizing carcinoid (medium proliferative activity) SS-R localized multiple metastases, whereas PET demonstrated low FDG uptake in all known metastases. In patients with recurrent MTC and rapidly increasing CEA levels DNS detected only three lesions in two patients, whereas PET demonstrated one pulmonary, three osseous, 20 mediastinal, ten locoregional, and four liver metastases in seven patients. Twenty-nine malignant lesions were confirmed by follow-up and nine lymph node metastases could be surgically removed. In conclusion, PET imaging of gastroenteropancreatic tumours revealed increased glucose metabolism only in less-differentiated GEP tumours with high proliferative activity and metastasizing MTC associated with rapidly increasing CEA levels. Therefore, additional ¹⁸F-FDG PET should be performed only if SS-R or DNS is negative. Received 8 July and in revised form 19 September 1997     

Diagnosis of thyroid lymphoma and follow-up evaluation using Ga-67 scintigraphy

A strong association between malignant lymphoma and Hashimoto's thyroiditis has frequently been reported. However, it is difficult to detect the lymphomatous transformation of Hashimoto's thyroiditis in the early stage. The purpose of the present study was to examine the usefulness of 67Ga scintigraphy in the diagnosis and evaluation of the therapeutic effects during follow-up, in patients with a suspected diagnosis of primary thyroid lymphoma. Twenty-five patients who were suspected of having primary thyroid lymphoma and had undergone 67Ga scintigraphy were studied. 67Ga planar scintigraphy was performed 72 hours after injection of 67Ga-citrate. The degree and pattern of 67Ga accumulation were graded visually. Histopathology on biopsy examination revealed thyroid lymphoma in 17 and Hashimoto's thyroiditis in 8 patients. Abnormal accumulation of 67Ga in the thyroid was seen in all of the 17 thyroid lymphoma cases with additional mediastinal and abdominal involvement in one. Fifteen of 17 thyroid lymphoma patients also underwent 67Ga scintigraphy 2-4 weeks after chemotherapy and/or radiotherapy. All 15 patients showed diminishing 67Ga accumulation and a good clinical course. In one patient with local recurrence, abnormal accumulation could be depicted by follow-up scintigraphy. However, diffuse or enlarged accumulation in the thyroid was seen in all of the 8 Hashimoto's thyroiditis cases. The degree of abnormal accumulation in the thyroid in clinically active phase thyroiditis was more intense than that in the chronic phase thyroiditis. 67Ga scintigraphy was helpful to confirm the diagnosis of thyroid lymphoma and to evaluate the therapeutic effects during follow-up. However, 67Ga scintigraphy may not always distinguish thyroid lymphoma from Hashimoto's thyroiditis, especially the active phase of the disease.     

胸部结节病的CT表现

目的 分析胸部结节病的CT表现，探讨其CT扫描和诊断价值。方法 13例胸部CT扫描患者，均在深吸气状态下摄片。在常规深吸气后屏气进行CT扫描，观察胸部淋巴结，肺部病变及胸膜病变。结果 13例均有胸部淋巴结增大，其中9例对称性两侧肺门淋巴结增大伴纵隔淋巴结增大，3例纵隔淋巴结增大伴单侧肺门淋巴结增大，1例仅有纵隔淋巴结增大而无肺门淋巴结增大。胸部病变有8例，占所有病例61．52％，表现为肺内多发结节，其中，3例伴肺内斑片状实变影，2例伴肺组织纤维化。胸膜病变仅1例，表现为胸膜多发小结节伴胸腔积液。结论 CT扫描是诊断结节病和鉴别诊断结节病的非常有效的方法，明显优于胸片。     

The role of technetium-99m sestamibi single photon emission tomography in the follow-up of malignant melanoma and the detection of lymph node metastases

In the follow-up of patients with malignant melanoma treated by surgical resection of the cutaneous tumour, it is important to achieve early detection of possible lymph node metastasis. In many cases, clinical examination alone will not be sufficient. In our study, single-photon emission tomography (SPET) with technetium-99m sestamibi (MIBI) was used in the assessment of 30 patients with previously resected malignant melanoma when the clinical examination raised the suspicion of lymph node metastasis. Using MIBI, 16 out of 17 lymph node metastases were detected and confirmed by histology. No false-positive results were obtained during this prospective study. It is concluded that MIBI scintigraphy may be useful in the early detection of lymph node metastases of malignant melanomas. If our preliminary results are confirmed, early detection of lymph node metastasis of previously resected malignant melanoma by ^99mTc-MIBI scintigraphy may have a significant impact on the management of these patients. Received 1 May and in revised form 13 August 1997     

Intrathoracic lymph node metastases from extrathoracic neoplasms.

The clinical records of 1,071 cases of extrathoracic malignant neoplasms seen over a 2 year period sere reviewed: 163 had abnormal chest films, and 25 of these showed evidence of mediastinal and/or hilar lymph node metastases. The primary malignancies which metastasized to intrathoracic lymph nodes included eight tumors of the head and neck, 12 genitourinary malignancies, three carcinomas of the breast, and two malignant melanomas. The chest films were analyzed to determine the distribution of lymph node groups involved. Unilateral lymph node enlargement occurred in eight. The most frequently detected lymph node group was the right paratracheal chain (60%), while the subcarinal and posterior mediastinal groups were rarely affected. Of the 25 cases, 10 had radiographic evidence of hematogenous or lymphangitic metastases in addition in the lungs. Metastatic disease from extrathoracic neoplasms should always be considered in the differential diagnosis of hilar and mediastinal adenopathy.     

Whole-body iodine-131 metaiodobenzylguanidine imaging for detection of bone metastases in patients with paraganglioma: comparison with bone scintigraphy

Iodine-131 metaiodobenzylguanidine (¹³¹I-MIBG) therapy is an effective treatment for patients with malignant paraganglioma for which surgical resection is not indicated. We performed high-dose ¹³¹I-MIBG therapy on two patients with malignant paraganglioma and multiple bone metastases. The bone metastases were diagnosed by magnetic resonance imaging (MRI). Metastatic bone lesions were evaluated by whole-body ¹³¹I-MIBG imaging and bone scintigraphy. Whole-body ¹³¹I-MIBG imaging showed extensive metastatic bone lesions, whereas conventional bone scintigraphy did not. There was a remarkable discrepancy between ¹³¹I-MIBG imaging and bone scintigraphy in the diagnosis of metastatic bone lesions of malignant paraganglioma in our two patients. High-dose ¹³¹I-MIBG imaging may detect early stages of bone metastases, compared with bone scintigraphy, in patients with malignant paraganglioma.