Subclinical thyroid disease after radiation therapy detected by radionuclide scanning

PURPOSE: The actuarial risk for developing benign or malignant thyroid disease following radiation therapy (RT) is controversial, but may be as high as 50% at 20 years. An effective screening modality should be specific but not overly sensitive, a limitation of ultrasound. We questioned whether Technetium-99 m pertechnetate ((99m)Tc TcO(4)(-)) scanning could detect clinically significant disease in ostensibly disease-free cancer survivors. METHODS AND MATERIALS: Eligibility criteria included an interval of at least 5 years after RT to the cervical region, a thyroid gland that was normal to palpation, euthyroid status determined by clinical examination, free T4 and TSH. The 34 patients scanned included 16 children (<18 years old) and 18 adults at the time of RT, 16 females and 18 males. The mean age at RT was 20 years (range, 2.1-50.3 years), and the mean age at (99m)Tc TcO(4)-scanning was 33 years (range, 13.6-58 years), providing a mean interval of 13 years (range, 5.3-26.6 years). The mean RT dose to the thyroid was 36.4 Gy (range, 19.5-52.5). Thyroid scanning was performed with a 5 mCi dose of (99m)Tc TcO(4)(-) obtaining flow, immediate and delayed static, and pinhole collimator images. RESULTS: Seven patients (21.6%) had abnormal scans, and the percentage was higher among children (25%) and females (25%) compared to adults (16.7%) and males (16.7%), respectively. Two of 34 patients (5.9%) were discovered to have a thyroid cancer; histopathologies were papillary and follicular carcinoma. CONCLUSION: In this population of clinically normal cancer survivors who had been irradiated to the cervical region, subclinical thyroid disease, of potential clinical significance, was detected by (99m)Tc TcO(4)(-) in about 20%. Children may be more commonly affected. Although the cost effectiveness of screening will require a larger sample number, we propose a surveillance schema for this patient population.     

Usefulness of 99mTc-tetrofosmin scintigraphy in different variants of Kaposi's sarcoma

We investigated (99m)Tc-tetrofosmin scintigraphy in 27 patients with Kaposi's sarcoma: 20 had classic (CK), 5 AIDS-associated (AK) and 2 transplantation-associated (TK) variants. Twenty-three patients had clinically evident cutaneous and/or mucosal lesions, 9 of them with associated sarcomatous lymphadenopathy; 2 TK patients had only lymph nodes or other extracutaneous Kaposi sites. Both planar and SPECT (99m)Tc-tetrofosmin scintigraphies were performed in all cases and neck pinhole (P)-SPECT in selected patients. (99m)Tc-tetrofosmin uptake was observed in 88% of patients with clinically evident cutaneous and/or extracutaneous Kaposi lesions. Scintigraphy gave additional information on cutaneous lesion extent, particularly SPECT regarding deep invasion and subclinical sites in some cases. However, scintigraphy was less sensitive in the detection of small, isolated and scattered lesions. SPECT/P-SPECT were positive in 8/8 patients with sarcomatous lymph nodes, planar imaging in 5/8, ultrasonography in 7/8, while all procedures were negative in 6 other patients with reactive or HIV infection lymph nodes. SPECT demonstrated lymphadenopathy remission in 1 TK patient after immunosuppressive therapy modification and, like planar imaging, ascertained an associated lymphoma with (67)Ga-citrate combined. (99m)Tc-tetrofosmin scintigraphy, especially SPECT, can be useful both in the detection and staging of Kaposi sarcoma lesions as a complementary tool to clinical and other conventional diagnostic methods.     

FDG-PET and stereotactic body radiotherapy (SBRT) for stage I non-small-cell lung cancer

PURPOSE: To investigate the utility of positron emission tomography (PET) in patients treated with stereotactic body radiotherapy (SBRT) for stage I non-small-cell lung cancer (NSCLC) on prospective institutional trials. PATIENTS AND METHODS: Fifty-eight patients with medically inoperable stage I NSCLC who participated in prospective phase I and II trials of SBRT, had >or=2 years of follow-up, and received FDG-PET imaging are the focus of this evaluation. Fifty-seven of 58 patients received pre-SBRT FDG-PET to confirm stage I status. All patients received stereotactic body frame immobilization and treatment with 7-10 photon beams. SBRT total doses ranged from 24 to 72Gy in three fractions. No elective nodal irradiation was undertaken. Regular follow-up with planned CT imaging was performed on all patients. Post-SBRT FDG-PET was not mandated by protocol and was typically ordered upon concern for disease recurrence. Thirty-eight post-SBRT PET studies were performed in 28 patients at a median 17.3 months following SBRT. RESULTS: With a median follow-up of 42.5 months, the 3-year actuarial overall survival and local control for this select subset of our SBRT experience were 48.9% and 74.8%, respectively. Pre-SBRT FDG-PET SUV did not predict 3-year overall survival or local control. Fourteen of 57 patients eventually failed in nodal stations by CT and/or PET. Isolated first site of failure was nodal in 6 patients (10%). Out of 28 patients with post-SBRT PET, 4 (14%) had delayed PET imaging (22-26 months after SBRT) showing moderate hypermetabolic activity (SUV 2.5-5.07), but no evidence of local, nodal, or distant recurrence by clinical examination and conventional imaging performed 20-26 months following these concerning PET findings. CONCLUSIONS: Isolated nodal recurrence following PET-staged I NSCLC treated with SBRT is uncommon. Moderate post-SBRT PET hypermetabolic activity may persist 2 years following treatment without definite evidence of recurrence. Further study is needed to confirm these results in larger populations with longer follow-up.     

Diagnostic imaging of bone metastasis from breast cancer

CONCLUSION: 1) Bone scintigraphy is the optimal screening procedure for bone metastasis from breast cancer. The question remains whether bone scintigraphy, from the standpoint of cost-effectiveness, should be performed in all breast cancer patients. 2) FDG-PET is anticipated to become more widely available in the near future for the detection of osseous and systemic metastasis. 3) X-ray CT, MRI and bone SPECT scanning should be properly used for detailed bone metastasis examination. 4) Gd-GTPA-enhanced MRI is of value in evaluating the therapeutic efficacies of treatments for bone metastasis. 5) Nuclear medicine imaging procedures (such as bone scintigraphy and(99m)Tc-MIBI scintigraphy) are anticipated to aid in the selection of appropriate therapeutic options for bone metastasis.     

The role of 99mTc-tetrofosmin Pinhole-SPECT in breast cancer axillary lymph node staging

The number of metastatic axillary nodes represents one of the most important prognostic factors in preoperative breast cancer patients. 99mTc-Tetrofosmin high resolution Pinhole (P)-SPECT was employed in 112 patients, 100 with breast cancer and 12 with benign mammary lesions, to ascertain axillary lymph node involvement. Axillary P-SPECT images were acquired utilizing specific software connected to a circular high resolution, single-head gamma camera equipped with a pinhole collimator with aperture size of 4.45 mm, rotating 180 degrees around the involved axilla. At the same time, patients also underwent conventional SPECT and planar acquisitions. Per-patient sensitivity and specificity were 100% and 93.6% for P-SPECT, 96.2% and 93.6% for SPECT and 56.6% and 100% for planar imaging, respectively. Moreover, P-SPECT detected more than 51% of lesions ascertained by histology, whereas SPECT and planar detected 32.6% and 20.3%, respectively. Only P-SPECT succeeded in identifying the exact number of metastatic axillary lesions in patients with multiple nodes; this procedure was able to correctly differentiate 88.67% of patients with 3 or less nodes from those with more than 3, thus giving important prognostic information. These data suggest 99mTc-Tetrofosmin P-SPECT is a reliable imaging method both for staging and prognostic purposes in breast cancer, and its routine use is recommended.     

The Na+/I- symporter mediates iodide uptake in breast cancer metastases and can be selectively down-regulated in the thyroid.

PURPOSE: The Na(+)/I(-) symporter (NIS) is a key plasma membrane protein that mediates active iodide (I(-)) transport in the thyroid, lactating breast, and other tissues. Functional NIS expression in thyroid cancer accounts for the longstanding success of radioactive iodide ((131)I) ablation of metastases after thyroidectomy. Breast cancer is the only other cancer demonstrating endogenous functional NIS expression. Until now, NIS activity in breast cancer metastases (BCM) was unproven. EXPERIMENTAL DESIGN: Twenty-seven women were scanned with (99m)TcO(4)(-) or (123)I(-) to assess NIS activity in their metastases. An (131)I dosimetry study was offered to patients with I(-)-accumulating tumors. Selective down-regulation of thyroid NIS was tested in 13 patients with T(3) and in one case with T(3) + methimazole (MMI; blocks I(-) organification). NIS expression was evaluated in index and/or metastatic tumor samples by immunohistochemistry. RESULTS: I(-) uptake was noted in 25% of NIS-expressing tumors (two of eight). The remaining cases did not show NIS expression or activity. Thyroid I(-) uptakes were decreased to 相似文献   

Assessment of residual tumour by FDG-PET: conventional imaging and clinical examination following primary chemotherapy of large and locally advanced breast cancer

Background:

The aim of this was to evaluate FDG-PET (2-(fluorine-18)-fluoro-2-deoxy-D-glucose positron emission tomography) for assessment of residual tumour after primary chemotherapy of large and locally advanced breast cancer in comparison with conventional imaging modalities.

Methods:

In a prospective multicentre trial, 99 patients underwent one or more breast imaging modalities before surgery in addition to clinical examination, namely, FDG-PET (n=89), mammography (n=47), ultrasound (n=46), and magnetic resonance imaging (MRI) (n=46). The presence of residual tumour by conventional imaging, dichotomised as positive or negative, and the level of FDG uptake (standardised uptake values, SUV) were compared with histopathology, which served as the reference standard. Patients with no residual tumour or only small microscopic foci of residual tumour were classified as having minimal residual disease and those with extensive microscopic and macroscopic residual tumour tissue were classified as having gross residual disease.

Results:

By applying a threshold SUV of 2.0, the sensitivity of FDG-PET for residual tumour was 32.9% (specificity, 87.5%) and increased to 57.5% (specificity, 62.5%) at a threshold SUV of 1.5. Conventional imaging modalities were more sensitive in identifying residual tumour, but had a low corresponding specificity; sensitivity and specificity were as follows: MRI 97.6 and 40.0%, mammography 92.5 and 57.1%, ultrasound 92.0 and 37.5%, respectively. Breast MRI provided the highest accuracy (91.3%), whereas FDG-PET had the lowest accuracy (42.7%).

Conclusions:

FDG-PET does not provide an accurate assessment of residual tumour after primary chemotherapy of breast cancer. Magnetic resonance imaging offers the highest sensitivity, but all imaging modalities have distinct limitations in the assessment of residual tumour tissue when compared with histopathology.     

SPECT/CT在大剂量131I治疗分化型甲状腺癌中的临床价值

目的:探讨大剂量131I治疗分化型甲状腺癌后131I-SPECT/CT断层融合显像的临床价值。方法:对2008年1月-2010年3月本院221例次术后分化型甲状腺癌大剂量131I治疗后4-7天行131 I全身扫描和病灶部位的131I-SPECT断层加同机CT融合显像,探讨断层融合显像的特点和临床价值。结果:断层融合显像能够获得直观的断层融合显像和三维立体图像,发现颈部转移淋巴节部位更准确、直观,更容易区分术后残余甲状腺与转移淋巴结;发现更多的病灶及更准确的判断病变部位;准确鉴别病灶和生理显影或污染;定位CT可以发现无摄碘功能的病灶。结论:大剂量131I治疗分化型甲状腺癌后行131I-SPET/CT断层融合显像检测131I在体内的分布,从而进行特异性诊断及疗效检测,有重要的临床价值。     

The role of technetium-99m methoxyisobutyl isonitrile scintigraphy in suspected recurrent breast cancer

The aim of this study was to determine the role of technetium-99m methoxyisobutyl isonitrile (99mTc-MIBI) scintigraphy in the evaluation of recurrence and metastases in breast cancer patients with mastectomy and/or radiotherapy. A prospective study was designed to assess the accuracy of 99mTc-MIBI scintigraphy in 36 patients (mean age 49 years) with suspected recurrent breast cancer. The scintigraphic studies were correlated with radiological findings and/or with histopathology. At 10-15 min after 740MBq 99mTc-MIBI injection, standard planar images were obtained in prone lateral and anterior supine views and then single-photon emission computed tomography (SPECT) imaging was performed. A whole body imaging was also performed to demonstrate distant metastatic lesions. Totally 52 lesions were evaluated which 19 of them in 9 patients were malignant, while 33 lesions in 27 patients were benign. The sensitivity was 33%, 88% and the specificity was 96%, 93% for planar and SPECT imaging, respectively in loco-regional lesions. Overall, the sensitivity and the specificity of MIBI imaging including whole body were 89%, 81%, in other conventional radiological imaging methods were 95%, 65%, respectively. 99mTc-MIBI scintigraphy using SPECT imaging may provide useful complementary information in patients with suspected recurrence breast cancer.     

Scintigraphic prediction of response to chemotherapy in patients with breast cancer: Technetium 99m-tetrofosmin and thallium-201 dual single photon emission computed tomography.

We have investigated the usefulness of dual-isotope single photon emission computed tomography (SPECT) for predicting the response to chemotherapy in patients with breast cancer. Twenty-five patients with breast cancer were analyzed by SPECT using both 99m-technetium-tetrofosmin (99mTc-TF) and 201-thallium-chloride (201Tl). The relationship between response to chemotherapy and retention of each tracer was analyzed. 99mTc-TF retention was significantly higher in responders (42.0+/-37.9) than in non-responders (-11.3+/-34.6) (p=0.003). Ten of 13 patients (76.9%) with high 99mTc-TF retention (>15%) showed good response to chemotherapy, whereas 11 of 12 patients (91.7%) with low 99mTc-TF retention (<15%) did not respond to the therapy. The overall predictability to the response to chemotherapy was 84.0%. 201Tl retention (responders, 47.5+/-60.2% vs. non-responders, 55.8+/-45.0%; p=0.443) was not useful in therapeutic prediction, but was required to identify the lesion on the SPECT image. This is the first report to find that dual-isotope SPECT using 99mTc-TF and 201Tl is useful in predicting the response to chemotherapy in patients with breast cancer. Low 99mTc-TF retention is a strong predictor of therapeutic resistance, and high 99mTc-TF retention suggests a favorable response to chemotherapy.     

18F]5-fluoro-2-deoxyuridine-PET for imaging of malignant tumors and for measuring tissue proliferation

The nucleoside 5-fluoro-2-deoxyuridine is a pyrimidine analogue accumulating in proliferative cells. We prospectively evaluated biodistribution of the PET tracer [(18)F]5-fluoro-2-deoxyuridine (FdUrd), its value for imaging malignant tumors, and its correlation to both [(18)F]2-fluoro-2-deoxyglucose (FDG)-PET findings and histological proliferation indices. In 11 previously untreated patients (5 lung carcinoma; 3 soft tissue sarcoma; 2 gastrointestinal carcinoma; 1 non-Hodgkin lymphoma [NHL]), mean doses of 290 MBq FdUrd and 390 MBq FDG were administered intravenously on subsequent days. Static PET scans were initiated 50-70 min after administration and the mean standardized uptake values (SUV) were calculated. Dynamic emission FdUrd scans were performed in 8/11 patients. Time-activity curves of blood and tumors as well as SUV of tumor lesions and organs were calculated. Proliferative activity was evaluated by Ki-67 immunohistostaining of biopsies. Tracer accumulated physiologically in liver, kidney, and bladder. SUVs were: kidney, 4.8 +/- 0.66; liver, 4.1 +/- 0.36; vertebrae, 0.70 +/- 0.17; spleen, 0.37 +/- 0.06; lungs, 0.19 +/- 0.05; femora/humeri, 0.14 +/- 0.03. Five patients exhibited significant intratumoral FdUrd-uptake (2 sarcomas; 1 NHL; 2 lung carcinomas) with mean SUVs ranging from 0.7 to 10.5. Metastases were not detected. Time-activity curves showed a rapid initial increase of intratumoral activity followed by activity retention. FDG-PET was positive in 10/11 patients. Correlation between the SUV of FdUrd-PET and FDG-PET or the tissue proliferation index, respectively, was not significant. FdUrd was a suitable tracer for imaging malignant tumors only in exceptional cases: Sarcoma, NHL, and some lung carcinomas were detected. FdUrd-PET was less effective than FDG-PET. In this group of patients, it was not useful in measuring tissue proliferation.     

Tryptophane-based biphenylsulfonamide matrix metalloproteinase inhibitors as tumor imaging agents

AIM: As a part of our efforts to use small organic matrix metalloproteinase (MMP) inhibitors with improved characteristics for the diagnosis and treatment of different kinds of tumor tissues, biphenylsulfonamide analogues were synthesized. This study reports on the in vivo biodistribution of iodine-123-labeled biphenylsulfonide and analogues in A549 lung carcinoma inoculated into athymic mice and the evaluation of their suitability as imaging agents using a single photon emission computed tomography (SPECT) camera. METHODS: The radioiodinated carboxylic and hydroxamic MMP inhibitors 2-(4'- [(123)I]iodobiphenyl-4-sulfonylamino)-3-(1H-indol-3-yl)-propionic acid (1') and 2-(4'-[(123)I]iodobiphenyl-4- sulfonylamino)-3-(1H-indol-3-yl)-propionamide (2') were synthesized by electrophilic aromatic substitution of the tributylstannyl derivatives. Planar gamma camera imaging was performed in nu/nu athymic mice bearing an A549 tumor using a Toshiba GCA-9300A/hg SPECT camera in planar mode equipped with a high-resolution, parallel-hole collimator. RESULTS: Radiosynthesis of (1') and (2') resulted in radiochemical yields of 60 +/- 5% (n +/- 3) and 70 +/- 5% (n = 6), respectively. Evaluation of tumors induced in athymic mice by the inoculation of non-small cell lung A549 carcinoma cells, showed a tumor uptake of 0.27-0.01 percent injected dose per gram (%ID/g) (3 hours-48 hours p.i.), a tumor-blood ratio of 0.7, a tumor-muscle ratio of 1.6, and a tumor-fat ratio of 0.5 at 24 hours (p.i.) for compound 1'. For compound 2' a tumor uptake of 0.7-0.04 %ID/g (3 hours-48 hours p.i.), a postinjection tumor-blood ratio of 1.2, a tumor-muscle ratio of 3.2, and a tumor-fat ratio of 2.4 at 48 hours p.i. was observed. SPECT evaluation confirmed the results obtained from biodistribution. CONCLUSION: In vivo evaluation of these radioiodinated carboxylic and hydroxamic MMP inhibitor tracers revealed that they do not appear suitable as tumor-imaging agents.     

Technetium-99m tetrofosmin SPECT predicts chemotherapy response in small cell lung cancer.

The multidrug resistance gene 1 encoding human P-glycoprotein (Pgp) is thought to play an important role in the multidrug resistance of lung cancer. The purpose of this study was to predict chemotherapy response by technetium-99m tetrofosmin (Tc-99m TF) lung single photon emission computed tomography (SPECT) and compare Pgp expression in patients with untreated small cell lung cancer (SCLC). Forty patients with untreated SCLC received Tc-99m TF lung SPECT prior to chemotherapy. The chemotherapy response was evaluated in the 3rd month after completion of treatment. Immunohistochemical staining of Pgp expression was performed on multiple nonconsecutive sections of biopsy specimens. By quantitative analyses, tumor to background ratios were 1.86 +/- 0.27 and 1.17 +/- 0.26 for patients with a good and poor response, respectively (p < 0.05). All of the 20 patients with a good chemotherapy response also had a positive Tc-99m TF lung SPECT and negative Pgp expression. In contrast, only 4 of the 20 patients with a poor chemotherapy response had a positive Tc-99m TF lung SPECT. Moreover, 10 of the 20 patients with a poor chemotherapy response also had negative Pgp expression (p < 0.05). Therefore, we concluded that Tc-99m TF lung SPECT can accurately predict the chemotherapy response, and Tc-99m TF lung SPECT findings can be partially compatible with Pgp expression in patients with untreated SCLC.     

Vinorelbine plus cisplatin versus cisplatin plus vindesine and mitomycin C in stage IIIB-IV non-small cell lung carcinoma: a prospective randomized study

This study was performed to investigate the utility of FDG-PET for: (1) initial staging, and (2) restaging of the primary and mediastinal nodal lesions 2 weeks after the completion of preoperative chemoradiotherapy in patients with stage III non-small cell lung cancer (NSCLC). Twenty-six patients with histologically confirmed stage III NSCLC were accrued to this study from April 1993 to July 1998. They included 21 with stage IIIA (N2) NSCLC who were enrolled into an institutional phase II study, and 5 patients with a highly selected subset of stage IIIB disease characterized by the presence of microscopic metastatic disease in contralateral mediastinal lymph nodes who were also treated with preoperative chemoradiotherapy; N3 lesions (n=3) and minimal T4 lesions. Demographic characteristics included median age 62 years (a range from 47 to 73) and gender ratio of male 15 to female 11. Histologic types of tumor consisted of squamous cell carcinoma 6, adenocarcinoma 11, large cell carcinoma 5, and non-small cell carcinoma 4. All patients had FDG-PET imaging of the chest before the initiation and 2 weeks after completion of preoperative therapy. The FDG-PET images were evaluated qualitatively for uptake at the primary tumor sites and mediastinal lymph nodes. Standard uptake values (SUVs) were also calculated for the primary tumors and all PET findings were correlated with surgical histopathologic data. Preoperative chemoradiotherapy resulted in complete pathologic response in 8 of 26 primary lesions. By qualitative analysis, 96% of these tumors showed level 3 or 4 uptake before preoperative chemoradiotherapy. After chemoradiotherapy, 57% (15/26) of patients showed at least a one level decrease in uptake, and the sensitivity and specificity of FDG-PET for differentiating residual tumor from pathologic complete response were 67% (12/18) and 63% (5/8). Mean SUV was 14.87+/-7.11 at baseline and decreased to 5.72+/-3.35 after chemoradiotherapy (n=21, P<0.00001). When a value of 3.0 was used as the SUV cut-off, sensitivity and specificity were 88 and 67%, respectively. The mean values of visual intensity were 3.87+/-0.35 and 3.8+/-0.51 for patients who achieved pathologic complete response (n=8) and for those who showed residual cancer after the preoperative therapy (n=18), respectively. The mean SUVs were 16.97+/-8.52 and 14.03+/-6.61 for patients who achieved pathologic complete response (n=6) and for those who showed residual cancer (n=15) after the preoperative therapy, respectively. Therefore, the degree of FDG uptake before preoperative chemoradiotherapy did not provide predictive value for subsequent tumor response. For mediastinal initial staging, the sensitivity and specificity of FDG-PET were 75 and 90.5%. The sensitivity and specificity of FDG-PET for mediastinal restaging were 58.0 and 93.0%. These results indicate that FDG-PET is useful for monitoring the therapeutic effect of neoadjuvant chemoradiotherapy in patients with stage III NSCLC. For the primary lesions, SUV based analysis has high sensitivity but limited specificity for detecting residual tumor. In contrast, for restaging of mediastinal lymph nodes, FDG-PET is highly specific, but has limited sensitivity.     

SPECT/CT在大剂量~（131）I治疗分化型甲状腺癌中的临床价值

目的：探讨大剂量131I治疗分化型甲状腺癌后131I-SPECT/CT断层融合显像的临床价值。方法：对2008年1月-2010年3月本院221例次术后分化型甲状腺癌大剂量131I治疗后4-7天行131 I全身扫描和病灶部位的131I-SPECT断层加同机CT融合显像,探讨断层融合显像的特点和临床价值。结果：断层融合显像能够获得直观的断层融合显像和三维立体图像,发现颈部转移淋巴节部位更准确、直观,更容易区分术后残余甲状腺与转移淋巴结;发现更多的病灶及更准确的判断病变部位;准确鉴别病灶和生理显影或污染;定位CT可以发现无摄碘功能的病灶。结论：大剂量131I治疗分化型甲状腺癌后行131I-SPET/CT断层融合显像检测131I在体内的分布,从而进行特异性诊断及疗效检测,有重要的临床价值。     

Evaluation of F18-deoxyglucose positron emission tomography (FDG-PET) to assess the nature of neurogenic tumours.

AIMS: Benign neurofibromas and malignant peripheral nerve sheath tumours (MPNST) commonly develop in patients with neurofibromatosis. Differentiation of benign from malignant tumours by conventional preoperative imaging is unreliable. FDG-PET is a non-invasive technique for biological tumour evaluation. The aim of this study was to assess the value of FDG-PET in patients with neurogenic tumours suspicious for MPNST. METHODS: Benign and malignant neurogenic soft tissue tumours were prospectively evaluated by computed tomography or magnetic resonance imaging. Three-dimensional qualitative and quantitative FDG-PET was performed. Standard uptake value (SUV) was analyzed with respect to histological diagnosis and follow-up data. RESULTS: Twenty-five neurogenic soft tissue tumours were included. FDG-PET identified all primary (n=6) and recurrent MPNST (n=7). Benign lesions (n=12) did not demonstrate high FDG uptake. The SUV was significantly higher in MPNST (median 2.9; range 1.8-12.3), than in benign tumours (median 1.1; range 0.5-1.8) (p<0.001). At a cut-off value of 1.8 SUV measured 1 h post-injection FDG-PET distinguished between MPNST and benign neurogenic tumours with 100% sensitivity and 83% specificity. CONCLUSIONS: FDG-PET allows discrimination of benign from malignant neurogenic tumours. This should be particularly useful in patients with neurofibromatosis as FDG-PET may help to avoid multiple surgical procedures for benign tumours.     

Biodistribution and imaging of FDG in rats with LS174T carcinoma xenografts and focal Escherichia coli infection

OBJECTIVE: The aim of this study was to compare the dynamic distribution of fluorodeoxyglucose (FDG) in malignant and in infectious lesions. METHODS: The dynamic distribution of FDG was studied in Rowett nude (RNU) rats with a LS174T carcinoma xenograft in the left front leg and an Escherichia coli-induced focal infection in the right front leg. In 5 rats, dynamic FDG-PET was performed (27 frames of 6-15 minutes) up to 4 hours after injection of 11 MBq 18FDG. The mean FDG uptake (SUV) was calculated and plotted by using a region of interest (ROI) centered over both lesions. In groups of 6 rats, the biodistribution of FDG was determined by counting dissected tissues at 1, 2, 3, and 4 hours after an injection of 11 MBq FDG. Means +/- the standard error of the mean (SEM) were calculated. RESULTS: Dynamic positron emission tomography (PET) visualized both the tumor and the infection. The ROI analysis showed that FDG uptake in the infections was faster and higher, as compared to the tumor lesions. FDG uptake in the tumor reached a standardized uptake value (SUV) of 0.8 +/- 0.3 at 60 minutes and in the infectious lesions a SUV of 1.6 +/- 0.2 at 45 minutes, both remaining constant until 4 hours postinjection (p.i.). In the biodistribution study with ex vivo tissue counting, FDG had accumulated up to 1.1 +/- 0.1 %ID/g and 0.8 +/- 0.1 %ID/g at 1 hour in the tumor and infection, respectively, and remained constant until 4 hours for both lesions without significantly different wash-out from the 2 lesions. The tumor/blood and abscess/ blood ratios increased with time to 57 +/- 17 and 48 +/- 14, respectively. CONCLUSION: Although in this model differences in absolute FDG uptake and initial kinetics between tumor and infection were observed, the wash-out rate of FDG from the lesions was similar over time. The retention of FDG in the inflammatory lesion indicated that dual time-point imaging does not necessarily resolve diagnostic pitfalls for FDG-PET in oncology in order to discriminate between malignant tumorous and benign infectious lesions.     

Using technetium-99m methoxyisobutylisonitrile lung single-photon-emission computed tomography to predict response to chemotherapy and compare with p-glycoprotein expression in patients with untreted small cell lung cancer

The purpose of this study was to predict chemotherapy response by technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) lung single-photon-emission computed tomography (SPECT) and compare P-glycoprotein (Pgp) expression in patients with untreated small cell lung cancer (SCLC). Before chemotherapy, 40 patients with untreated SCLC underwent Tc-99m MIBI lung SPECT. Immunohistochemical analyses were performed using multiple nonconsecutive sections of the biopsy specimens to detect Pgp expression. Chemotherapy response was evaluated in the third month after completion of treatment by clinical and radiological methods. Based on quantitative analyses, the tumor uptake ratios (TUR) of the 20 patients with good response (1.89 +/- 0.28) were significantly higher than that of the 20 patients with poor response (1.21 +/- 0.28) (p value < 0.05). Based on visual interpretation, all of the 20 patients (100%) with good response had positive Tc-99m TF lung SPECT findings and negative Pgp expression. Five of the other 20 patients (25%) with poor response had positive Tc-99m MIBI lung SPECT findings, and 12 of the other 20 patients (60%) with poor response had negative Pgp expression (p value < 0.05). Negative Tc-99m MIBI lung SPECT findings could predict poor response. Therefore, we concluded that Tc-99m MIBI lung SPECT can accurately predict the chemotherapy response, and Tc-99m MIBI lung SPECT findings can be partially compatible with Pgp expression in patients with untreated SCLC.     

99mTc-tetrofosmin SPECT in solitary pulmonary nodule evaluation

A correct differential diagnosis between benign and malignant lesions is mandatory in patients with solitary pulmonary nodule (SPN). The aim of the present study was to investigate whether 99mTc-tetrofosmin SPECT may play a role in SPN evaluation. A consecutive series of 111 patients with an uncalcified 相似文献   

Time course of tumor metabolic activity during chemoradiotherapy of esophageal squamous cell carcinoma and response to treatment.

PURPOSE: To evaluate the time course of therapy-induced changes in tumor glucose use during chemoradiotherapy of esophageal squamous cell carcinoma (ESCC) and to correlate the reduction of metabolic activity with histopathologic tumor response and patient survival. PATIENTS AND METHODS: Thirty-eight patients with histologically proven intrathoracic ESCC (cT3, cN0/+, cM0) scheduled to undergo a 4-week course of preoperative simultaneous chemoradiotherapy followed by esophagectomy were included. Patients underwent positron emission tomography with the glucose analog fluorodeoxyglucose (FDG-PET) before therapy (n = 38), after 2 weeks of initiation of therapy (n = 27), and preoperatively (3 to 4 weeks after chemoradiotherapy; n = 38). Tumor metabolic activity was quantitatively assessed by standardized uptake values (SUVs). Results Mean tumor FDG uptake before therapy was 9.3 +/- 2.8 SUV and decreased to 5.7 +/- 1.9 SUV 14 days after initiation of chemoradiotherapy (-38% +/- 18%; P <.0001). The preoperative scan showed an additional decrease of metabolic activity to 3.3 +/- 1.1 SUV (P <.0001). In histopathologic responders (< 10% viable cells in the resected specimen), the decrease in SUV from baseline to day 14 was 44% +/- 15%, whereas it was only 21% +/- 14% in nonresponders (P =.0055). Metabolic changes at this time point were also correlated with patient survival (P =.011). In the preoperative scan, tumor metabolic activity had decreased by 70% +/- 11% in histopathologic responders and 51% +/- 21% in histopathologic nonresponders. CONCLUSION: Changes in tumor metabolic activity after 14 days of preoperative chemoradiotherapy are significantly correlated with tumor response and patient survival. This suggests that FDG-PET might be used to identify nonresponders early during neoadjuvant chemoradiotherapy, allowing for early modifications of the treatment protocol.