The value of 18F-FDG PET in the detection of stage M0 carcinoma of the nasopharynx.

Distant metastasis is an important issue for nasopharyngeal carcinoma (NPC). The potential value of PET using 18F-FDG has not been well defined. This prospective study investigated the impact of 18F-FDG PET in NPC patients with stage M0 disease. METHODS: From April 2001 to June 2003, 140 NPC patients (118 primary and 22 primary recurrent) with stage M0 (negative results from chest radiography, liver sonography, and whole-body bone scanning) underwent 18F-FDG PET to check for distant metastases. Confirmatory MRI or CT was performed if any abnormal 18F-FDG uptake was found at distant sites. The distant lesion was confirmed pathologically, if feasible, and was followed up clinically and with imaging for at least 6 mo. RESULTS: 18F-FDG PET detected 26 true-positive metastatic sites in 18 (12.9%) of the 140 patients, among whom 14 had primary and 4 had recurrent tumors. The patient-based sensitivity and specificity of 18F-FDG PET for distant metastases were 100% and 86.9%, respectively. Mediastinal lymph nodes (n = 8) were the most common sites, followed by lung, liver, and bone (n = 5 each) and by other lymph nodes (n = 3). In patients with primary tumors, advanced nodal status (N2-3) was a statistically significant variable associated with development of distant metastases (P = 0.044). For recurrent NPC, neither age, sex, initial tumor stage, grade of differentiation, nor nodal stage showed a statistically significant difference between patients with and patients without distant metastases. CONCLUSION: 18F-FDG PET is valuable in avoiding aggressive locoregional radiotherapy in some NPC patients by the revelation of occult distant metastases, especially in patients with primary disease at a nodal stage of N2-3.     

The role of (18)F-FDG PET/CT in initial staging of patients with locally advanced breast carcinoma with an emphasis on M staging

Locally advanced breast cancer (LABC) is a distinct entity in breast carcinoma with high incidence of distant metastases (M). However, there is scarce data in the literature addressing the role of fluorine-18-fluorodeoxyglucose-positron emission tomography/computed tomography ((18)F-FDG PET/CT) in LABC. This study was performed to assess the sensitivity of (18)F-FDG PET/CT in confirming known lymph nodal and M and in identifying new ones in LABC. We performed a retrospective analysis of data of 16 patients with LABC who underwent histopathology, for the diagnosis of LABC and clinical examination, chest X-rays, ultrasound of the abdomen and whole body bone scans. Findings for M obtained by all the above examinations were compared to the (18)F-FDG PET/CT findings that followed. Lymph nodal and distant metastases detected by all other examinations were detected by (18)F-FDG PET/CT in all patients, except subcentimetric metastases in 2 patients in the axilla that were detected in another examination later. Additionally, (18)F-FDG PET/CT identified unknown ipsilateral, supraclavicular, internal mammary metastases and upstaged disease in 3 patients and additional distant metastases were noted in 3/16 patients. In conclusion, our study suggests that more extra axillary lymph nodal and distant metastases can be identified by (18)F-FDG PET/CT as compared to a group of clinical, X-rays, ultrasound and bone scan examinations together.     

Routine (18)F-FDG PET preoperative staging of colorectal cancer: comparison with conventional staging and its impact on treatment decision making.

The preoperative staging of colorectal cancer (CRC) with (18)F-FDG PET is not as yet generally considered to be evidence based. We have found only 1 study that evaluated (18)F-FDG PET in a nonselected population with proven CRC. Several other studies have concentrated on more advanced disease. The aim of this study was to assess the potential clinical benefit of (18)F-FDG PET in the routine staging of CRC. METHODS: Thirty-eight consecutive patients who had had CRC histologically proven by colonoscopy underwent prospective preoperative staging by plain chest radiography, sonography, CT, and (18)F-FDG PET. Sensitivity, specificity, and accuracy were retrospectively assessed by comparison with the histologic results after surgery (36 patients) or clinical follow-up (2 inoperable cases-both patients died within 1 y of the PET examination). The impact of (18)F-FDG PET on therapeutic decision making was evaluated by comparing medical records before and after (18)F-FDG PET. RESULTS: (18)F-FDG PET correctly detected 95% of primary tumors, whereas CT and sonography correctly detected only 49% and 14%, respectively. Lymph nodes were involved in 7 patients. The sensitivity, specificity, and accuracy of (18)F-FDG PET were 29%, 88%, and 75%, respectively. CT and sonography did not reveal any lymph node involvement. Liver metastases were present in 9 patients. (18)F-FDG PET, CT, and sonography had a sensitivity of 78%, 67%, and 25%, respectively; a specificity of 96%, 100%, and 100%, respectively; and an accuracy of 91%, 91%, and 81%, respectively. (18)F-FDG PET revealed further lesions in 11 patients. Levels of carcinoembryonic antigen and carbohydrate antigen 19-9 tumor markers were elevated in, respectively, only 33% and 8% of cases of proven CRC. (18)F-FDG PET changed the treatment modality for 8% and the range of surgery for 13% of patients. In total, (18)F-FDG PET changed the method of treatment for 16% of patients. CONCLUSION: Plain chest radiography and sonography did not bring any clinical benefits. No correlation was found between the level of tumor markers and the stage of disease. CT is necessary for confirmation of PET findings at extraabdominal sites (PET-guided CT) and for their morphologic specification at abdominal and pelvic sites before an operation. (18)F-FDG PET is the best method for the staging of CRC in all localities, despite the high rate of false-negative PET findings in patients with lymph node involvement. PET should be performed as a first examination after verification of CRC. We propose a PET/CT hybrid system as optimal in the staging of CRC.     

Clinical utility of 18F-FDG PET for patients with salivary gland malignancies.

The clinical utility of 18F-FDG PET in evaluating salivary gland malignancies has not been well defined. We therefore evaluated the utility of 18F-FDG PET in management for patients with salivary gland cancers. METHODS: Thirty-four patients with newly diagnosed salivary gland cancers underwent CT and 18F-FDG PET before surgical resection with radiotherapy. The diagnostic accuracies of CT and 18F-FDG PET for detecting primary tumors and neck metastases were compared with a histopathologic reference. We determined the relationship between the maximum standardized uptake value (SUV) of the tumor and clinicopathologic parameters such as sex, age, local tumor invasion, T and N categories, TNM stage, and histologic grade, as well as their associations with disease-free survival (DFS). RESULTS: 18F-FDG PET was more sensitive than CT for the detection of primary tumors (91.2% vs. 79.4%; P < 0.05), cervical metastases (80.5% vs. 56.1%; P < 0.05), and distant metastases in 2 patients at initial staging. High-grade malignancies had higher mean maximum SUVs than did low- and intermediate-grade malignancies (4.6 vs. 2.8; P = 0.011). T and N categories were independent determinants of DFS (P < 0.05), but the maximum SUV (4.0) was not. During a mean follow-up of 25.1 mo, 18F-FDG PET correctly diagnosed local-regional recurrences in 6 patients and new distant metastases in 9 patients. CONCLUSION: Our findings indicate that, in patients with salivary gland malignancies, 18F-FDG PET is clinically useful in initial staging, histologic grading, and monitoring after treatment but not in predicting patient survival.     

The impact of 18F-FDG PET/CT on assessment of nasopharyngeal carcinoma at diagnosis

The aim of this study was to determine whether the use of whole-body (18)F-fluoro-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography (PET)/CT alters staging and management of nasopharyngeal carcinoma (NPC) when compared with current staging practice. 52 patients with Stage III-IV NPC without distant metastases on chest X-ray/CT, abdominal ultrasound or bone scan were recruited for the study. Whole-body (18)F-FDG PET/CT and MRI of the head and neck were performed. The scans were compared for extent of the primary tumour (PT), cervical nodal metastases (CNM) and distant metastases (DM). Any discordance in results was assessed with respect to staging and impact on management. MRI and (18)F-FDG PET/CT scans were discordant in 28 (54%) patients. There was discordance in the extent of PT at 28 sites; in all sites, MRI showed more extensive tumour involving the nasopharynx (n = 8), skull base (n = 14), brain (n = 4) and orbit (n = 2). There was also variation among the extent of CNM in four nodes of the retropharyngeal region, with the nodes being positive on MRI. (18)F-FDG PET /CT did not identify any additional distant metastases but did identify a second primary tumour in the colon. The additional use of (18)F-FDG PET/CT did not "up-stage" the overall stage or change management in any patient. In conclusion, there is discordance between MRI and (18)F-FDG PET/CT, and the additional use of (18)F-FDG PET/CT for the current assessment of NPC at diagnosis does not appear to be justified in this cohort of patients.     

18F-FDG PET对原发性食管癌和复发性食管癌的诊断价值

食管癌的预后较差,手术的致死率和致残率均较高,术前正确分期对确定治疗方案显得尤为重要.PET是继CT、MRI、食管镜等常规检查的有益补充.受分辨率的影响,PET较难确定肿瘤的局部浸润程度,在局部淋巴结转移方面其价值有待于进一步的研究,但对远处转移灶的诊断明显优于CT、MRI等常规检查,诊断复发性食管癌准确率较高,能有效鉴别手术疤痕和复发,有效评价放化疗的疗效.结合传统影像学检查,18F-FDG能较为准确地进行术前分期,纠正不正确的治疗方案,改善食管癌的预后.     

Diagnostic accuracy of 18F-FDG PET/CT in characterizing ovarian lesions and staging ovarian cancer: correlation with transvaginal ultrasonography, computed tomography, and histology

AIMS: To (a) assess the accuracy of 18F-FDG PET/CT in distinguishing malignant from benign pelvic lesions, compared to transvaginal ultrasonography (TVUS) and (b) to establish the role of whole-body 18F-FDG PET/CT, compared to contrast enhanced computed tomography (CT), in staging patients with ovarian cancer. PATIENTS: Fifty consecutive patients with a pelvic lesion, already scheduled for surgery on the basis of physical examination, TVUS, and serum Ca125 levels, were enrolled in the study. Patients' age ranged between 23 and 89 years (mean 64). All patients underwent TVUS including a colour Doppler study followed by a thorax and abdominal CT scan, and whole-body 18F-FDG PET/CT within 2 weeks prior to surgery. Histological findings obtained at surgery were taken as the 'gold standard' to compare 18F-FDG PET/CT and TVUS, and 18F-FDG PET/CT vs. CT. When tissue analysis showed ovarian cancer, the accuracy of 18F-FDG PET/CT and CT were compared for the purpose of obtaining a precise staging. RESULTS: At surgery, the ovarian lesions were malignant in 32/50 patients (64%) and benign in the remaining 18/50 patients (36%). The sensitivity, specificity, NPV, PPV and accuracy of 18F-FDG PET/CT were 87%, 100%, 81%, 100% and 92%, respectively, compared with 90%, 61%, 78%, 80% and 80%, respectively, for TVUS. In staging ovarian cancer, 18F-FDG PET/CT results were concordant with final pathological staging in 22/32 (69%) patients while CT results were concordant in 17/32 (53%) patients. CT incorrectly down-staged four out of six stage IV patients by missing distant metastasis in the liver, pleura, mediastinum, and in left supraclavicular lymph nodes, which were correctly detected by 18F-FDG PET/CT. CONCLUSION: PET/CT with 18F-FDG provides additional value to TVUS for the differential diagnosis of benign from malignant pelvic lesions, and to CT for the staging of ovarian cancer patients.     

18F-FDG PET and CT/MRI in oral cavity squamous cell carcinoma: a prospective study of 124 patients with histologic correlation.

Accurate evaluation of primary tumors and cervical lymph node status of squamous cell carcinoma (SCC) of the oral cavity is important to treatment planning and prognosis prediction. In this prospective study, we evaluated the use of 18F-FDG PET, CT/MRI, and their visual correlation for the identification of primary tumors and cervical nodal metastases of SCC of the oral cavity with histologic correlation. METHODS: One hundred twenty-four patients with pathologically proven diagnoses of oral cavity SCC underwent 18F-FDG PET and CT/MRI within 2 wk before surgery. We interpreted 18F-FDG PET, CT/MRI, and visually correlated 18F-FDG PET and CT/MRI separately to assess the primary tumors and their regional lymph node status. We recorded lymph node metastases according to the neck level system of imaging-based nodal classification. Histopathologic analysis was used as the gold standard for assessment of the primary tumors and lymph node involvement. We analyzed differences in sensitivity and specificity among the imaging modalities using the McNemar test. The receiver-operating-characteristic (ROC) curve and calculation of the area under the curve were used to evaluate their discriminative power. RESULTS: The accuracy of 18F-FDG PET, CT/MRI, and their visual correlation for the identification of primary tumors was 98.4%, 87.1%, and 99.2%, respectively. The sensitivity of 18F-FDG PET for the identification of nodal metastases on a level-by-level basis was 22.1% higher than that of CT/MRI (74.7% vs. 52.6%, P < 0.001), whereas the specificity of 18F-FDG PET was 1.5% lower than that of CT/MRI (93.0% vs. 94.5%, P = 0.345). The sensitivity and specificity of the visual correlation of 18F-FDG PET and CT/MRI were 3.2% and 1.5% higher than those of 18F-FDG PET alone (77.9% vs. 74.7%, P = 0.25; 94.5% vs. 93.0%, P = 0.18, respectively). The area under the curve obtained from the ROC curve showed that 18F-FDG PET was significantly superior to CT/MRI for total nodal detection (0.896 vs. 0.801, P = 0.002), whereas the visual correlation of 18F-FDG PET and CT/MRI was modestly superior to 18F-FDG PET alone (0.913 vs. 0.896, P = 0.28). CONCLUSION: 18F-FDG PET is superior to CT/MRI in the detection of cervical status of oral cavity SCC. The sensitivity of 18F-FDG PET for the detection of cervical nodal metastasis on a level-by-level basis was significantly higher than that of CT/MRI, whereas their specificities appeared to be similar. Visual correlation of 18F-FDG PET and CT/MRI showed a trend of increased diagnostic accuracy over 18F-FDG PET alone but without a statistically significant difference, and its sensitivity was still not high enough to replace pathologic lymph node staging based on neck dissection.     

Breast cancer staging in a single session: whole-body PET/CT mammography

Our objective was to compare the diagnostic accuracy of an all-in-one protocol of whole-body 18F-FDG PET/CT and integrated 18F-FDG PET/CT mammography with the diagnostic accuracy of a multimodality algorithm for initial breast cancer staging. METHODS: Forty women (mean age, 58.3 y; range, 30.8-78.4 y; SD, 12 y) with suspected breast cancer were included. For the primary tumor, we compared 18F-FDG PET/CT mammography versus MRI mammography; for axillary lymph node status, 18F-FDG PET/CT versus clinical investigation and ultrasound; and for distant metastases, 18F-FDG PET/CT versus a multimodality staging algorithm. Histopathology and clinical follow-up served as the standard of reference. The Fisher exact test evaluated the significance of differences (P < 0.05). Alterations in patient management caused by 18F-FDG PET/CT were documented. RESULTS: No significant differences were found in the detection rate of breast cancer lesions (18F-FDG PET/CT, 95%; MRI, 100%; P = 1). 18F-FDG PET/CT correctly classified lesion focality significantly more often than did MRI (18F-FDG PET/CT, 79%; MRI, 73%; P < 0.001). MRI correctly defined the T stage significantly more often than did 18F-FDG PET/CT (MRI, 77%; 18F-FDG PET/CT, 54%; P = 0.001). 18F-FDG PET/CT detected axillary lymph node metastases in 80% of cases; clinical investigation/ultrasound, in 70%. This difference was not statistically significant (P = 0.067). Distant metastases were detected with 18F-FDG PET/CT in 100% of cases, and the multimodality algorithm identified distant metastases in 70%. This difference was not statistically significant (P = 1). Three patients had extraaxillary lymph node metastases that were detected only by PET/CT (cervical, retroperitoneal, mediastinal/internal mammary group). 18F-FDG PET/CT changed patient management in 12.5% of cases. CONCLUSION: Our data suggest that a whole-body 18F-FDG PET/CT mammography protocol may be used for staging breast cancer in a single session. This initial assessment of the 18F-FDG PET/CT protocol indicates similar accuracy to MRI for the detection of breast cancer lesions. Although MRI seems to be more accurate when assessing the T stage of the tumor, 18F-FDG PET/CT seems able to more accurately define lesion focality. Although 18F-FDG PET/CT mammography was able to detect axillary lymph node metastases with a high sensitivity, this method cannot soon be expected to replace the combination of clinical examination, ultrasound, and sentinel lymph node biopsy for axillary assessment.     

CT及18F-FDGPET/CT诊断食管癌术前淋巴结转移及N分期对比研究

目的 研究CT及18F-氟脱氧葡萄糖(FDG) PET/CT术前诊断食管癌淋巴结转移及确定N分期的价值.资料与方法 连续随机选择经食管镜或胃镜证实、拟行手术治疗、能够耐受手术的47例食管癌患者,术前1周内行CT及18F-FDG PET/CT检查,以术后病理为“金标准”,比较CT及18F-FDG PET/CT诊断食管癌淋巴结转移及N分期的敏感性、特异性、准确性、阳性预测值及阴性预测值.结果 31例存在淋巴结转移,共切除并分离淋巴结387枚(209组),其中65枚(46组)发现转移.CT诊断淋巴结转移的敏感性、特异性、准确性、阳性预测值、阴性预测值分别为53.8％、92.8％、86.3％、60.3％和90.9％;18F-FDG PET/CT分别为89.2％、93.8％、93.0％、74.4％和97.7％.PET/CT诊断淋巴结转移的敏感性、准确性及阴性预测值均显著高于CT,差异有统计学意义(P＜0.05),特异性及阳性预测值差异无统计学意义(P＞0.05).CT及18F-FDG PET/CT确定淋巴结分期的准确率分别为74.5％和91.5％,差异有统计学意义(P＜0.05).伴淋巴结转移的食管癌原发灶最大标准摄取值(SUVmax)为( 14.899±3.770),而无淋巴结转移者为(9.427±2.854).结论 18F-FDGPET/CT术前诊断食管癌淋巴结转移及确定N分期优于CT;食管癌原发灶SUVmax在一定程度上可以反映淋巴结转移情况.     

18F-氟脱氧葡萄糖PET及PET-CT在食管癌中的应用价值

食管癌的预后较差,切除术的致死率和致残率较高,术前正确分期对确定治疗方案尤为重要。PET是对CT、MRI、食管镜等常规检查的有益补充。受分辨率的影响,PET较难确定肿瘤的浸润程度,但对远处转移灶的诊断明显优于CT、MRI等常规检查,诊断复发性食管癌准确率较高,能有效鉴别手术瘢痕和复发,有效评价放疗、化疗的疗效。结合传统影像学检查,18F-氟脱氧葡萄糖PET及PET-CT能较为准确地进行术前分期,纠正不正确的治疗方案,改善食管癌患者的预后。     

18F-FDG PET/CT在胃癌中的临床应用进展

胃癌是全球范围内最常见的恶性肿瘤之一。18F-氟脱氧葡萄糖（FDG）PET/CT在胃癌中的应用既有优点又有局限性。胃癌原发灶对18F-FDG的摄取与癌症分期、组织学分型和肿瘤大小密切相关。早期胃癌18F-FDG摄取阳性预示着内镜黏膜下剥离术的不可治愈性。进展期胃癌的最大标准化摄取值（SUV_max）在肠型与印戒细胞癌（SRC）或弥漫型胃癌间的差异显著,SRC的SUV_max与患者的总生存时间和无病生存时间呈负相关。18F-FDG PET/CT对区域淋巴结转移的诊断灵敏度较低,但其特异度很高,区域淋巴结对18F-FDG摄取呈阳性是预后不良的指征。18F-FDG PET/CT可检出隐匿的远处转移（7.2%~10.0%）,其中大部分（4.7%~8.8%）使用腹腔镜也不能检出。常规性应用18F-FDG PET/CT并联合腹腔镜检查对明确胃癌分期的意义重大。因此,笔者就18F-FDG PET/CT在胃癌中的临床应用进展进行综述。     

Current relevance of cervical ultrasonography in staging cancer of the esophagus and gastroesophageal junction

PURPOSE: To evaluate the value of external ultrasonography (US) of the neck in current dedicated preoperative staging of patients with cancer of the esophagus and gastroesophageal junction (GEJ). MATERIALS AND METHODS: We analyzed 180 consecutive patients (154 men, 26 women, and mean age 63 (38-84) years) without palpable cervical lymphadenopathy, treated between January 2001 and March 2006. Suspicious lesions were confirmed by cytological examination. All first 125 consecutive patients (group A) were staged by standard endoscopic ultrasonography (EUS), multidetector computed tomography (md-CT), positron emission tomography with (18)F-fluorodeoxyglucose (FDG-PET) and external US. The other 55 patients (group B) were prospectively staged according to a revised protocol consisting of routine EUS and md-CT, while PET was only performed in subjects with T3-T4 and/or N1 disease and external US solely on indication. RESULTS: Cervical metastases were found in seven patients from group A (6%) and in five from group B (9%). Twenty percent (4/20) of the tumors above the carina and 5% (8/160) of the distal tumors presented with cervical metastases. All were diagnosed as T3 and T4 tumors on EUS. Eleven of these metastases were detected by external US and nine on md-CT. All nodal metastases were detected by the combination of PET and md-CT. No cervical metastases were missed by the diagnostic algorithm in group B. CONCLUSION: In present staging procedures for esophageal cancer, routine external US seems to have no additional value in detecting cervical metastases. It is still indicated to obtain cytological proof of suspected cervical lesions.     

血管免疫母细胞T细胞淋巴瘤^18MF-FDGPET/CT的影像表现及其在临床分期中的价值

目的分析血管免疫母细胞T细胞淋巴瘤（angioimmunoblasticT-celllymphoma,AITL）^18F-FDGPET/CT的影像学表现及分布规律,探讨其在临床分期中的价值。方法回顾性分析22例AITL患者的^18F-FDGPET/CT显像结果,评价其在临床分期中的价值。结果（1）AITL结内侵犯的^18F-FDGPET/CT影像学表现：①全身弥漫性分布：左右对称性分布9例（40．9％）,左右不对称性分布2例（9．1％）;②多部位散在分布：与淋巴链走行有关4例（18．2％）,与淋巴链走行无关5例（22．7％）;③单部位局限性分布2例（9．1％）;（2）AITL结外侵犯的^18F-FDGPET／CT影像学表现：鼻咽部侵犯最常见有10例,其余依次为口咽8例,脾脏8例,骨骼及骨髓5例,胃肠道4例,肺、胸膜及皮肤各2例,乳腺及颅内侵犯各1例;（3）在AITL分期中的价值：PET/CT显像改变了4例（18．2％,4/22）患者的分期,均为分期上调。结论血管免疫母细胞T细胞淋巴瘤呈”F-FDG高摄取;其在病灶检测及分期方面,^18F-FDGPET/CT显像有优势。     

Staging primary head and neck cancers with <Superscript>18</Superscript>F-FDG PET/CT: is intravenous contrast administration really necessary?

Purpose  The aim of our study was to prospectively evaluate whether intravenous contrast media in integrated positron emission tomography and computed tomography (PET/CT) with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) significantly contributes to evaluation of primary head and neck cancers compared with unenhanced PET/CT, regional contrast-enhanced CT of head and neck (neck CE-CT) and regional magnetic resonance imaging of head and neck (neck MRI). Methods  Subjects were 42 consecutive patients (35 men, 7 women; age range: 36–91 years) with biopsy-proven primary head and neck cancers. Lesion detection of primary and nodal sites and TNM classification were assessed on a per-patient basis. McNemar test and κ statistics were employed for statistical analyses. Results  Forty patients (95%) were successfully followed up: 24 patients had nodal disease and 3 had distant metastasis. Contrast-enhanced and unenhanced PET/CT detected 98 and 95% of the primary tumours, respectively, and both detected 92% of patients with nodal disease, which revealed no statistically significant difference. Accuracy for T status was 75 and 73%, respectively, which proved significantly more accurate than neck CE-CT, which had an accuracy of 53% (p = 0.0133 and 0.0233, respectively). Neck MRI correctly classified the T status in 58% of patients; however, no statistically significant difference was found between PET/CT and neck MRI. Contrast-enhanced PET/CT, unenhanced PET/CT, neck CT and neck MRI correctly staged the N status in 90, 90, 79 and 90% of patients, respectively, with no statistically significant difference. Overall TNM classification was correctly classified in 68 and 65% of patients, respectively. Weighted κ values between enhanced and unenhanced PET/CT for primary tumour detection, nodal detection, T status and N status were 0.655, 1.000, 0.935 and 1.000, respectively. Conclusion  We found almost perfect correlation between enhanced and unenhanced PET/CT for lesion detection and initial staging of primary head and neck cancers. Routine contrast administration for PET/CT imaging may not be justified.     

18F-FDG PET versus CT for evaluating the spleen during initial staging of lymphoma

The purpose of this study was to compare (18)F-FDG PET to CT for evaluating the spleen during the initial staging of lymphoma. METHODS: Seven patients with newly diagnosed lymphoma underwent (18)F-FDG PET and CT. Splenic uptake of (18)F-FDG, diffuse or focal, greater than hepatic uptake was interpreted as consistent with tumor. CT demonstrating a positive splenic index or focal hypodensities was classified as positive for tumor. PET and CT results were compared with final diagnoses, which were confirmed surgically for 6 patients and at autopsy for 1 patient. RESULTS: Five of 7 patients had lymphomatous involvement of the spleen. (18)F-FDG PET was true-positive for all 5 patients with splenic disease and true-negative for both patients without splenic disease. CT, in contrast, was true-positive for 4 of the 5 patients with splenic disease and false-positive for the 2 patients without splenic disease. The accuracies of (18)F-FDG PET and CT for evaluating the spleen were 100% and 57%, respectively. CONCLUSION: (18)F-FDG PET correctly identified all patients with and without splenic disease and was superior to CT for this purpose.     

A rare case of malignant urinary bladder paraganglioma with distant metastases demonstrated by 18F-FDG PET/CT

Urinary bladder paragangliomas are rare tumors, with malignant ones being still rarer. Demonstration of metastases by imaging is crucial, as histological examination of primary cannot reliably distinguish between benign and malignant tumors. We describe a rare case of a patient with malignant urinary bladder paraganglioma in whom 18F-FDG PET/CT was useful in detection of regional lymph nodal and distant metastases. In addition, 18F-FDG PET/CT suggested an easily accessible site of biopsy to confirm the metastatic disease.     

18F-FDG PET/CT for staging of penile cancer.

The value of PET or PET/CT with (18)F-FDG for the staging of penile cancer has yet to be determined. The objective of this study was to investigate the pattern of (18)F-FDG uptake in the primary malignancy and its metastases and to determine the diagnostic value of (18)F-FDG PET/CT in the staging and restaging of penile cancer. METHODS: Thirteen patients (mean +/- SD age, 64 +/- 14.0 y) with suspected penile cancer or suspected recurrent disease were examined with a Gemini PET/CT system (200 MBq of (18)F-FDG). The reference standard was based on histopathologic findings obtained at biopsy or during surgery. RESULTS: Both the primary tumor and regional lymph node metastases exhibited a pattern of (18)F-FDG uptake typical for malignancy. Sensitivity in the detection of primary lesions was 75% (6/8), and specificity was 75% (3/4). On a per-patient basis, sensitivity in the detection of lymph node metastases was 80% (4/5), and specificity was 100% (8/8). On a nodal-group basis, PET/CT showed a sensitivity of 89% (8/9) in the detection of metastases in the superficial inguinal lymph node basins and a sensitivity of 100% (7/7) in the deep inguinal and obturator lymph node basins. The mean +/- SD maximum standardized uptake value for the 8 primary lesions was 5.3 +/- 3.7, and that for the 16 lymph node metastases was 4.6 +/- 2.0. CONCLUSION: According to our results, the main indication for (18)F-FDG PET in the primary staging or follow-up of penile cancer patients may be the prognostically crucial search for lymph node metastases. With the use of a PET/CT unit, the additional information provided by CT may be especially useful for planning surgery. Implementing (18)F-FDG PET and PET/CT in future staging algorithms may lead to a more precise and stage-appropriate therapeutic strategy. Furthermore, invasive procedures with a high morbidity rate, such as general bilateral lymphadenectomy, may be avoided.     

18F-FDG PET/CT显像在恶性胸膜间皮瘤诊断中的价值

目的 探讨18F-脱氧葡萄糖(FDG)PET/CT显像在恶性胸膜间皮瘤(MPM)诊断中的临床价值及原发肿瘤病灶平均标准摄取值(SUVmax)对患者预后的判断价值.方法 回顾性总结17例2002-2008年临床疑诊MPM患者18F-FDG PET/CT显像资料,测量病灶的SUVmax.将病理检查及临床随访证实的MPM患者按照有无转移分为2组,测定每例患者原发肿瘤病灶的SUVmax,用受试者工作特征(ROC)曲线评价SUVmax对患者转移与否的诊断价值,判断预后.采用SPSS 11.0软件进行t检验.结果 经病理及随访结果证实MPM 12例,良性胸膜病变5例,二者的SUVmax分别为5.78±1.81和2.72±2.51,差异有统计学意义(t=2.8,P<0.05).全身18F-FDG PET/CT显像诊断MPM的灵敏度为100%(12/12),特异性为4/5,准确性为94%(16/17),18F-FDG PET/CT显像有7例MPM伴有骨和(或)淋巴结转移.SUVmaxROC曲线分析表明曲线下面积(AUC)为0.80.结论 全身18F-FDG PET/CT显像对于MPM的诊断有重要价值.原发肿瘤病灶SUVmax越高越易发生转移,预后越差.     

Fluorine-18 fluorodeoxyglucose PET/CT patterns of extranodal involvement in patients with Non-Hodgkin lymphoma and Hodgkin's disease

Lymphoma may originate in extranodal sites. Extranodal lymphoma may also be secondary to and accompany nodal disease. Fluorine-18 fluorodeoxyglucose (18F-FDG) imaging has an essential role in the staging of lymphoma, in monitoring the response to therapy, and in detection of recurrence. The introduction of 18F-FDG PET/CT hybrid imaging allows for accurate localization of disease and may be specifically beneficial for the detection of unexpected extranodal sites of disease or exclusion of disease in the presence of nonspecific extranodal CT findings. Accurate staging and localization often dictate the appropriate treatment strategy in patients with lymphoma. Therefore, at any stage in the course of the disease, the potential presence of extranodal disease should be considered when interpreting 18F-FDG PET/CT studies in patients with non-Hodgkin lymphoma and Hodgkin's disease.