Role of 18F-FDG PET/CT in staging and follow-up of lymphoma in pediatric and young adult patients

OBJECTIVE: To assess the role of 18F-Fluorodeoxyglucose (18F-FDG) PET/CT in pediatric patients with Hodgkin disease (HD) and non-Hodgkin lymphoma (NHL). MATERIALS AND METHODS: 31 patients, mean age 12.9 +/- 5.1, HD (n = 24), and NHL (n = 7) underwent 18F-FDG PET/CT at diagnosis (n = 31 studies) and later in the course of the disease (n = 75 studies). The findings of PET/CT were correlated with diagnostic CT and clinical follow-up. RESULTS: PET/CT findings resulted in a change of disease staging in 10 patients (32.3%), upstaging in 7 (22.6%) and downstaging in 3 (9.6%). On a lesion analysis, 164 disease sites were detected by PET/CT of which 38 were overlooked by DCT.At mid-treatment, PET was negative in 28 out of 31 patients (90%) with negative predictive value of 96% as all latter patients except for 1, were disease free (mean 15.4 +/- 8.8 months). The positive predictive value of persistent increased 18F-FDG uptake was 100% as 3 patients with latter findings had active disease. On the CT part, 76 residual masses were identified in 22 patients. Increased 18F-FDG uptake was detected in 11 masses in 4 patients who had active disease. Remaining 65 PET negative masses were false positive findings. The positive predictive value of residual CT mass was 14%. CONCLUSIONS: PET/CT is associated with change in staging in approximately 1 out of 3 pediatric patients with HD and NHL. When used for monitoring response to treatment, a negative study is associated with disease-free period, even when residual mass is detected. A positive PET study indicates residual malignant disease.     

18F-FDG PET for evaluation of the treatment response in patients with gastrointestinal tract lymphomas.

(18)F-FDG PET is highly sensitive and specific for evaluation of the treatment response of nodal and extranodal diseases in patients with malignant lymphomas. However, no data are available in the literature with regard to (18)F-FDG PET for evaluation of the treatment response in patients with lymphomas with gastrointestinal tract (GIT) involvement. This study was undertaken to investigate the usefulness of (18)F-FDG PET in monitoring the response to the treatment of lymphomas in this setting. METHODS: We retrospectively analyzed 19 patients with different types of lymphomas (10 diffuse large B-cell lymphomas, 4 follicular lymphomas, 3 mantle cell lymphomas, and 2 Hodgkin's disease) involving GIT. Among 19 patients, 4 had gastric involvement, 13 had small bowel involvement, and 2 had small bowel plus colon involvement by lymphomas. All patients underwent (18)F-FDG PET before and after the completion of therapy. The results of (18)F-FDG PET were compared with the results of CT and clinical outcome; the presence of relapse was determined on the basis of positive biopsy results or clinical follow-up data. RESULTS: Of the 19 posttreatment PET scans, 13 showed no pathologic (18)F-FDG uptake, whereas 6 showed persistent (18)F-FDG uptake. Among the 13 patients who had negative PET scans, only 1 patient (7.7%) relapsed, whereas all 6 patients (100%) who had persistent abnormal (18)F-FDG uptake on posttherapy PET scans relapsed. Posttreatment CT scans were negative for 10 patients but showed persistent disease in the remaining 9 patients. Among the 10 patients who had negative CT scans, 9 remained in remission and 1 (10%) relapsed. Of the 9 patients who showed persistent disease, 6 (67%) relapsed and 3 (33%) remained in remission after the mean follow-up of 20 mo. The sensitivity, specificity, positive and negative predictive values, and accuracy of posttherapy (18)F-FDG PET were 86%, 100%, 100%, 92%, and 95%, respectively. The corresponding values for CT were 67%, 75%, 75%, 90%, and 79%, respectively. Patients with positive (18)F-FDG PET results had statistically significantly lower disease-free survival (DFS) (0%) than did those with positive CT results (33%) (P = 0.04). There was no statistically significant difference in DFS between patients with negative (18)F-FDG PET results and patients with negative CT results. CONCLUSION: A positive (18)F-FDG PET scan after the completion of chemotherapy in patients with lymphomas with GIT involvement is a strong predictor of relapse. (18)F-FDG PET has higher diagnostic accuracy than CT in the detection of residual disease after therapy. Despite the mild physiologic (18)F-FDG uptake in the GIT, (18)F-FDG PET has potential value in monitoring the response to treatment in patients with GIT lymphomas, particularly when pretreatment PET results are positive.     

Clinical utility of 18F-FDG PET/CT in assessing the neck after concurrent chemoradiotherapy for Locoregional advanced head and neck cancer.

For patients with locoregional advanced head and neck squamous cell carcinoma (HNSCC), concurrent chemoradiotherapy is a widely accepted treatment, but the need for subsequent neck dissection remains controversial. We investigated the clinical utility of 18F-FDG PET/CT in this setting. METHODS: In this Institutional Review Board (IRB)-approved and Health Insurance Portability and Accountability Act (HIPPA)-compliant retrospective study, we reviewed the records of patients with HNSCC who were treated by concurrent chemoradiation therapy between March 2002 and December 2004. Patients with lymph node metastases who underwent 18F-FDG PET/CT > or = 8 wk after the end of therapy were included. 18F-FDG PET/CT findings were validated by biopsy, histopathology of neck dissection specimens (n = 18), or clinical and imaging follow-up (median, 37 mo). RESULTS: Sixty-five patients with a total of 84 heminecks could be evaluated. 18F-FDG PET/CT (visual analysis) detected residual nodal disease with a sensitivity of 71%, a specificity of 89%, a positive predictive value (PPV) of 38%, a negative predictive value (NPV) of 97%, and an accuracy of 88%. Twenty-nine heminecks contained residual enlarged lymph nodes (diameter, > or =1.0 cm), but viable tumor was found in only 5 of them. 18F-FDG PET/CT was true-positive in 4 and false-positive in 6 heminecks, but the NPV was high at 94%. Fifty-five heminecks contained no residual enlarged nodes, and PET/CT was true-negative in 50 of these, yielding a specificity of 96% and an NPV of 98%. Lack of residual lymphadenopathy on CT had an NPV of 96%. Finally, normal 18F-FDG PET/CT excluded residual disease at the primary site with a specificity of 95%, an NPV of 97%, and an accuracy of 92%. CONCLUSION: In patients with HNSCC, normal 18F-FDG PET/CT after chemoradiotherapy has a high NPV and specificity for excluding residual locoregional disease. In patients without residual lymphadenopathy, neck dissection may be withheld safely. In patients with residual lymphadenopathy, a lack of abnormal 18F-FDG uptake in these nodes also excludes viable tumor with high certainty, but confirmation of these data in a prospective study may be necessary before negative 18F-FDG PET/CT may become the only, or at least most-decisive, criterion in the management of the neck after chemoradiotherapy.     

18F-FDG PET for posttherapy assessment of Hodgkin's disease and aggressive Non-Hodgkin's lymphoma: a systematic review.

Although studies have shown that (18)F-FDG PET, when used to assess the response of malignant lymphoma after treatment, has a strong ability to predict relapse, its diagnostic accuracy in clinical practice remains unclear. The aim of this study was to systematically review the diagnostic accuracy of (18)F-FDG PET in detecting residual disease at the completion of first-line therapy of Hodgkin's disease (HD) and aggressive non-Hodgkin's lymphoma (NHL). METHODS: We searched relevant articles from 1966 to July 2006 using MEDLINE, EMBASE, SCOPUS, Biological Abstracts, bibliographies, review articles, and textbooks without language restriction. One assessor (for non-English-language studies) or 2 assessors (for English-language studies) independently reviewed each article to abstract relevant study characteristics and results. Relevant individual patient data or subgroup data were provided by the investigators if they were unavailable from the publications. We estimated summary receiver operating characteristic curves and confidence regions for summary sensitivity and specificity. RESULTS: Nineteen studies consisting of 474 HD and 254 aggressive NHL patients were included. These studies had heterogeneity and suboptimal methodologic quality and reporting. Reported ranges for the sensitivity and specificity of (18)F-FDG PET in predicting disease relapse were 0.50-1.00 and 0.67-1.00, respectively, for HD and 0.33-0.77 and 0.82-1.00, respectively, for NHL. These estimates were similar when conventional imaging tests showed a residual mass. For HD studies, the summary receiver operating characteristic curves were similar irrespective of whether a residual mass was detected by conventional tests. Factors explaining the variability of diagnostic estimates were not identified. CONCLUSION: Although currently available evidence is still limited, (18)F-FDG PET seems to have good diagnostic accuracy for assessing residual HD at the completion of first-line treatment. Clinical data on this use of (18)F-FDG PET for aggressive NHL are more limited. Prospective studies with a more rigorous research design, conduct, and reporting would more reliably reveal the clinical diagnostic accuracy of this imaging modality.     

18F-FDGPET／CT诊断腹膜转移瘤的临床价值

目的评价18F-脱氧葡萄糖（FDG）PET／CT在腹膜转移瘤诊断中的临床价值。方法回顾性分析22例有原发恶性肿瘤手术史或不明原因腹腔积液而临床高度怀疑腹膜转移的患者资料。所有病例均行18F—FDGPET／CT检查,经病理检查或临床随访证实。结果22例中,有18例18F-FDGPET／CT诊断阳性,其中16例确诊腹膜转移,2例确诊为腹腔结核;4例PET／CT诊断阴性,其中3例确诊为腹膜炎性病变,1例确诊为腹膜转移瘤。18F—FDGPET／CT诊断腹膜转移瘤的灵敏度为94．1％（16／17）,特异性为3／5,阳性预测值为88．9％（16／18）,阴性预测值为3／4,准确性为86．4％（18／22）。结论在诊断腹膜转移瘤方面,18F—FDGPET／CT是一种可靠的、准确性较高的无创性检查,有重要的临床应用价值。     

~(18)F-FDG PET-CT和双源CT的LungCare软件在评估孤立性肺结节中的比较研究

目的 探讨18-氟-脱氧葡萄糖(~(18)F-FDG)PET/CT显像及Siemens双源CT的LungCare软件对孤立性肺结节(SPN)的辅助诊断能力及适用范围.方法 回顾分析经病理证实的24例SPN患者的PET-CT图像资料,并与利用双源CT的LungCare软件分析SPN进行比较研究.用χ~2检验对2种检查方法的评价结果进行统计学分析,以P<0.05作为差异有显著意义.结果 在24例SPN中,恶性结节15例,良性结节9例.LungCare软件评估其良恶性的准确性、敏感性、特异性、阳性预测值、阴性预测值分别为83.3%、80.0%、88.8%、92.3%、72.7%,PET-CT评估其良恶性的准确性、敏感性、特异性、阳性预测值、阴性预测值分别为87.5%、93.3%、77.7%,87.5%、87.5%.LungCare软件和PET/CT定性SPN的准确性相当,两者之间并不存在明显的差异(P>0.05).PET/CT的敏感性、阴性预测值明显高于LungCare软件,但其特异性、阳性预测值明显低于LungCare软件(P<0.05).结论 ~(18)F-FDG PET-CT对肺结节的诊断有一定辅助作用,适用于对孤立性肺结节的良恶性鉴别诊断.PET/CT密切结合LungCare软件,可进一步提高诊断正确率.     

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.     

PET predicts prognosis after 1 cycle of chemotherapy in aggressive lymphoma and Hodgkin's disease.

Early identification of chemotherapy-refractory lymphoma patients provides a basis for alternative treatment strategies. Metabolic imaging with (18)F-FDG PET offers functional tissue characterization that is useful for assessing response to therapy. Our objective was to determine the predictive value of (18)F-FDG PET early during chemotherapy (after 1 cycle) and at the completion of chemotherapy for subsequent progression-free survival (PFS) in patients with aggressive non-Hodgkin's lymphoma (NHL) or Hodgkin's disease (HD). METHODS: (18)F-FDG PET (dual-head coincidence camera with attenuation correction) was performed before and after 1 cycle of chemotherapy on 30 patients (17 NHL, 13 HD; mean age, 52.3 +/- 16.0 y). For 23 of the 30 patients, (18)F-FDG PET data were also obtained after the completion of chemotherapy. The patients had a median follow-up of 19 mo (range, 18-24 mo). Follow-up of PFS was compared between patients with positive and negative (18)F-FDG PET results obtained after the first cycle of chemotherapy and at the completion of chemotherapy. RESULTS: Positive (18)F-FDG PET results obtained both after the first cycle and at the completion of therapy were associated with a shorter PFS (median, 5 and 0 mo, respectively) than were negative (18)F-FDG PET results (PFS medians not reached). A statistically significant difference in PFS between positive and negative (18)F-FDG PET results was obtained both after the first cycle and at the completion of chemotherapy (P < or = 0.001). The PFS and (18)F-FDG PET results obtained after the first cycle correlated better than those obtained after the completion of chemotherapy (r(2) = 0.45 vs. 0.17). (18)F-FDG PET had more false-negative results after the last cycle (6/17 cases, or 35%) than after the first cycle (2/13 cases, or 15%). Thus, (18)F-FDG PET had greater sensitivity and positive predictive values after the first cycle (82% vs. 45.5% and 90% vs. 83%, respectively) than after the last cycle. CONCLUSION: (18)F-FDG PET after 1 cycle of chemotherapy is predictive of 18-mo outcome in patients with aggressive NHL and HD and may earlier identify patients who would benefit from more intensive treatment programs.     

Whole-body (18)F-FDG PET identifies high-risk myeloma.

The purpose of this study was to evaluate the clinical utility of whole-body PET with (18)F-FDG in patients with multiple myeloma and related monoclonal diseases. METHODS: Between July 1, 1996, and July 2000, 98 (18)F-FDG PET scans were obtained for 66 patients, with 25 patients having 2 or more scans. The results were compared with routine clinical and staging information, including CT and MRI scans, as indicated. Of the 66 patients, 16 had previously untreated active myeloma, 14 had monoclonal gammopathy of undetermined significance (MGUS), 10 had disease in remission, and 26 had relapsing disease. RESULTS: Negative whole-body (18)F-FDG PET findings reliably predicted stable MGUS. Of the 14 MGUS patients with follow-up of 3-43+ mo, myeloma has developed in only 1 (7%), at 8 mo. Conversely, the 16 previously untreated patients with active myeloma all had focal or diffusely positive scan findings. Four (25%) of 16 previously untreated patients with positive (18)F-FDG PET findings had negative full radiologic surveys. Another 4 (25%) of 16 patients had focal extramedullary disease. This was confirmed by biopsy or other imaging techniques. Extramedullary uptake also occurred in 6 (23%) of 26 patients with relapse. This extramedullary uptake was a very poor prognostic factor both before treatment and at relapse. For example, median survival was 7 mo for patients with disease relapse. Persistent positive (18)F-FDG PET findings after induction therapy predicted early relapse. In 13 (81%) of 16 patients with relapsing disease, new sites of disease were identified. The (18)F-FDG PET results were especially helpful in identifying focal recurrent disease in patients with nonsecretory or hyposecretory disease amenable to local irradiation therapy, which was used in 6 patients. CONCLUSION: Whole-body (18)F-FDG PET provides important prognostic information, which is clinically useful and complementary to conventional methods of evaluating plasma cell disorders. (18)F-FDG PET is a unique tool for evaluation of nonsecretory myeloma. Residual or recurrent disease after therapy, especially extramedullary disease, is a poor prognostic factor.     

Role of (18)F-FDG dual-head gamma-camera coincidence imaging in recurrent or metastatic colorectal carcinoma.

(18)F-FDG PET has been shown to be of high diagnostic accuracy for the evaluation of recurrent colorectal cancer. However, the limited availability of PET scanners precludes (18)F-FDG assessment of many patients for whom the study is indicated. An alternative is the SPECT system in coincidence mode. The aim of this study was to determine the role of dual-head camera (18)F-FDG coincidence imaging (DHC (18)F-FDG) in patients with recurrent colorectal cancer. METHODS: Sixty-seven DHC (18)F-FDG studies were performed on 62 patients with suspected recurrent colorectal cancer. Reports of contemporary CT were available for the purpose of correlation for 61 of the studies. The final diagnosis of the imaging findings was based on histology or clinical and imaging follow-up of at least 6 mo. RESULTS: In lesion-based analysis, 103 tumor sites were suspected on DHC (18)F-FDG, CT, or colonoscopy. Ninety-three of them were found to be true tumor sites. For DHC (18)F-FDG, the sensitivity was 88%, specificity was 80%, positive predictive value (PPV) was 98%, negative predictive value (NPV) was 42%, and accuracy was 87%. For CT, the sensitivity was 63%, specificity was 10%, PPV was 85%, NPV was 3%, and accuracy was 57%. In patient-based analysis, DHC (18)F-FDG differentiated patients with recurrent cancer from disease-free patients with a sensitivity of 91%, specificity of 73%, PPV of 94%, NPV of 62%, and accuracy of 88%. DHC (18)F-FDG detected tumor sites in 12 (67%) of 18 patients with elevated carcinoembryonic antigen and negative CT findings. CONCLUSION: DHC (18)F-FDG is an adequate readily available technique for assessment of recurrent colorectal cancer and has a diagnostic accuracy better than that of CT.     

The role of 18F-FDG PET in staging and early prediction of response to therapy of recurrent gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are gaining the interest of researchers because of impressive metabolic response to the targeted molecular therapeutic drug imatinib mesylate. Initial reports suggest an impressive role for (18)F-FDG PET in follow-up of therapy for these tumors. However, the role of (18)F-FDG PET versus that of CT has not been established. Therefore, we compared the roles of (18)F-FDG PET and CT in staging and evaluation of early response to imatinib mesylate therapy in recurrent or metastatic GIST. METHODS: The study included 54 patients who underwent (18)F-FDG PET and CT scans within 3 wk before initiation of imatinib mesylate therapy. Forty-nine of these patients underwent repeat scans 2 mo after therapy. The numbers of sites or organs containing lesions on (18)F-FDG PET and CT scans were compared. Corresponding lesions on (18)F-FDG PET and CT scans or those confirmed to be malignant in appearance by other imaging modalities or on follow-up were considered true positives. Lesions seen on (18)F-FDG PET or CT scans but not seen or confirmed to be of benign appearance with other imaging modalities or on follow-up were considered false positives. Measurements of the maximum standard uptake value (SUV) on (18)F-FDG PET scans and tumor size on CT scans were used for quantitative evaluation of early tumor response to therapy. RESULTS: A total of 122 and 114 sites and/or organs were involved on pretherapy (18)F-FDG PET and CT scans, respectively. The sensitivity and positive predictive values (PPVs) for CT were 93% and 100%; whereas these values for (18)F-FDG PET were 86% and 98%. However, the differences between these values for CT and (18)F-FDG PET were not statistically significant (P = 0.27 for sensitivity and 0.25 for PPV). This suggests comparable performance of (18)F-FDG PET and CT in staging GISTs. Repeat scans at 2 mo after therapy showed agreement between (18)F-FDG PET and CT scans in 71.4% of patients (57.1% having a good response to therapy and 14.3% lacking a response). Discrepant results between (18)F-FDG PET and CT were recorded for 28.6% of the patients. (18)F-FDG PET predicted response to therapy earlier than did CT in 22.5% of patients during a longer follow-up interval (4-16 mo), whereas CT predicted lack of response to therapy earlier than (18)F-FDG PET in 4.1%. One patient did not undergo long-term follow-up. These findings suggest that (18)F-FDG PET is superior to CT in predicting early response to therapy in recurrent or metastatic GIST patients. CONCLUSION: The performances of (18)F-FDG PET and CT are comparable in staging GISTs before initiation of imatinib mesylate therapy. However, (18)F-FDG PET is superior to CT in predicting early response to therapy. Thus, (18)F-FDG PET is a better guide for imatinib mesylate therapy.     

18F-FDG PET/CT in patients with suspected recurrent or metastatic well-differentiated thyroid cancer.

PET using 18F-FDG has been shown to effectively detect various types of cancer by their increased glucose metabolism. The aim of this study was to evaluate the use of coregistered PET and CT (PET/CT) in patients with suspected thyroid cancer recurrence. METHODS: After total thyroidectomy followed by radioiodine ablation, 61 consecutive patients with elevated thyroglobulin levels or a clinical suspicion of recurrent disease underwent 18F-FDG PET/CT. Of these, 59 patients had negative findings on radioiodine (131I) whole-body scintigraphy (WBS). Fifty-three of the 61 patients had both negative 131I WBS findings and elevated thyroglobulin levels. PET/CT images were acquired 60 min after intravenous injection of 400-610 MBq of 18F-FDG using a combined PET/CT scanner. Any increased 18F-FDG uptake was compared with the coregistered CT image to differentiate physiologic from pathologic tracer uptake. 18F-FDG PET/CT findings were correlated with the findings of histology, postradioiodine WBS, ultrasound, or clinical follow-up serving as a reference. The diagnostic accuracy of 18F-FDG PET/CT was evaluated for the entire patient group and for those patients with serum thyroglobulin levels of less than 5, 5-10, and more than 10 ng/mL. RESULTS: Thirty patients had positive findings on 18F-FDG PET/CT; 26 were true-positive and 4 were false-positive. In 2 patients, increased 18F-FDG uptake identified a second primary malignancy. 18F-FDG PET/CT results were true-negative in 19 patients and false-negative in 12 patients. The overall sensitivity, specificity, and accuracy of 18F-FDG PET/CT were 68.4%, 82.4%, and 73.8%, respectively. The sensitivities of 18F-FDG PET/CT at serum thyroglobulin levels of less than 5, 5-10, and more than 10 ng/mL were 60%, 63%, and 72%, respectively. Clinical management changed for 27 (44%) of 61 patients, including surgery, radiation therapy, or chemotherapy. CONCLUSION: Coregistered 18F-FDG PET/CT can provide precise anatomic localization of recurrent or metastatic thyroid carcinoma, leading to improved diagnostic accuracy, and can guide therapeutic management. In addition, the findings of this study suggest that further assessment of 131I WBS-negative, thyroglobulin-positive patients by 18F-FDG PET/CT may aid in the clinical management of selected cases regardless of the thyroglobulin level.     

Whole-body (18)F-FDG PET and conventional imaging for predicting outcome in previously treated breast cancer patients.

This study was conducted to determine the ability of (18)F-FDG PET and conventional imaging (CI) to predict the outcomes in breast cancer patients who have previously undergone primary treatment. METHODS: The study population consisted of 61 female patients (median age, 54 y; range, 32--91 y) who were reevaluated with (18)F-FDG PET and CI after treatment. The median interval between the last treatment and PET was 0.4 y (range, 0--16 y). PET was performed within 3 mo of CI (median interval, 25 d; range, 2--84 d). To determine the independent impact of PET on outcome, PET images were reinterpreted in a blind fashion. Availability of clinical information after PET scanning (21 plus minus 12 mo) was required for study inclusion. Study endpoints were clinical evidence of progression of disease or death. RESULTS: Of 61 patients, 19 (31.1%) had no clinical evidence and 38 (62.3%) had evidence of residual or recurrent disease by the end of follow-up. Four patients (6.6%) had died. The positive and negative predictive values (PPV and NPV, respectively) of PET were 93% and 84%, respectively. CI yielded a PPV of 85% and an NPV of 59%. The prognostic accuracy of single whole-body PET was superior to that of multiple procedures with CI (90% vs. 75%; P < 0.05). Kaplan--Meier estimates of disease-free survival in patients with negative PET findings compared with those with positive PET findings revealed a significant difference between the 2 curves (log-rank test = 0.001). Kaplan--Meier estimates of disease-free survival stratified by CI results showed a marginally significant difference between CI-positive and CI-negative patients (log-rank test = 0.04). CONCLUSION: FDG PET can be used to improve prediction of the clinical outcome of previously treated breast cancer patients relative to what is achievable through CI alone.     

18F-FDG PET显像诊断原发性鼻咽癌的价值

目的　探讨18F 脱氧葡萄糖 (FDG)PET显像对原发性鼻咽癌的诊断价值。方法　对 51例受检者行18F FDGPET显像 ,其中 3 1例行病理组织学检查 ,最后诊断根据病理组织学检查结果和临床随访。结果　18F FDGPET显像诊断原发性鼻咽癌的灵敏度为 96.0 0 % ,特异性为 76 92 % ,阳性预测值为 80 .0 0 % ,阴性预测值为 95 2 4% ,准确性为 86 2 7%。鼻咽癌、鼻咽炎症和无鼻咽病变组标准摄取值 (SUV)均值比较 ,3组间差异有显著性 (F =2 1 3 0 ,P <0 0 1)。结论　18F FDGPET显像诊断原发性鼻咽癌具有高灵敏度和高阴性预测值     

Detection of Richter's transformation of chronic lymphocytic leukemia by PET/CT.

Our objective was to evaluate the accuracy of PET/CT for the diagnosis of Richter's transformation of chronic lymphocytic leukemia (CLL) to diffuse large cell lymphoma. METHODS: A retrospective study was performed of 37 patients with CLL who underwent 18F-FDG PET/CT at our institution between March 2003 and July 2005. All PET/CT scans were reviewed in consensus by 2 diagnostic radiologists. Sites of abnormal 18F-FDG uptake with a maximum standardized uptake value (SUVmax) of greater than 5 were considered highly suggestive of Richter's transformation. The PET/CT findings were correlated with histologic findings from bone marrow or lymph node biopsy performed within 6 wk of PET/CT and with clinical follow-up. RESULTS: The 37 patients (26 men and 11 women; mean age, 61 y, range, 40-82 y) underwent 57 PET/CT scans. In 10 (91%) of 11 patients with Richter's transformation, PET/CT detected sites of abnormal 18F-FDG uptake having an SUVmax of greater than 5. Richter's transformation was missed in 1 patient who had only low-grade 18F-FDG uptake (SUVmax < 5). Nine patients had false-positive PET/CT findings; in 3 of these patients, alternative malignancies were diagnosed (Hodgkin's disease; metastatic neuroendocrine carcinoma; non-small cell lung cancer). In all remaining patients, PET/CT correctly excluded Richter's transformation. For the specific diagnosis of Richter's transformation of CLL to diffuse large B-cell lymphoma, PET/CT had overall sensitivity, specificity, and positive and negative predictive values of 91%, 80%, and 53% and 97%, respectively. CONCLUSION: PET/CT can detect Richter's transformation of CLL to diffuse large B-cell lymphoma with a high sensitivity and a high negative predictive value.     

Evaluation of therapy for lymphoma

Positron emission tomography (PET) using (18)F-fluorodeoxyglucose ((18)F-FDG) is the best noninvasive imaging technique for to assess response in patients suffering from lymphoma. Early response evaluation ("interim PET") after one, a few cycles, or at midtreatment can predict response, progression-free survival, and overall survival. We calculated from data of 7 studies an overall sensitivity to predict treatment failure of 79%, a specificity of 92%, a positive predictive value (PPV) of 90%, a negative predictive value (NPV) of 81%, and an accuracy of 85%. Although it is not yet indicated to change patient management based on residual (18)F-FDG uptake on interim scan in chemotherapy-sensitive patients, prospective studies evaluating the role of an interim PET in patient management clearly are warranted. (18)F-FDG PET also has an important prognostic role in relapsing patients after reinduction chemotherapy before high-dose chemotherapy (HCT) followed by autologous stem cell transplantation (ASCT). However, all chemotherapy-sensitive patients remain candidates for HCT followed by ASCT, even if (18)F-FDG PET showed residual (18)F-FDG uptake. We calculated from data of 3 studies an overestimated risk of relapse in 16% of all PET-positive patients. Some patients with residual (18)F-FDG uptake will have a good outcome after HCT followed by ASCT. (18)F-FDG PET is the imaging technique of choice for end-of-treatment evaluation. However, (18)F-FDG is not specific for tumoral tissue. Active inflammatory lesions and infectious processes can be falsely interpreted as malignant residual cells. However, a negative (18)F-FDG PET cannot exclude minimal residual disease. Consequently, it is always indicated to correlate PET findings with clinical data, other imaging modalities, and/or a biopsy. We calculated, from data of 17 studies in end-of-treatment evaluation, a sensitivity of 76%, a specificity of 94%, a PPV of 82%, a NPV 92%, and an accuracy of 89%.     

The role of <Superscript>18</Superscript>F-FDG PET/CT in the detection of osteosarcoma recurrence

Aim

The aim of this study was to investigate the diagnostic accuracy of ¹⁸F-FDG-PET/CT in osteosarcoma patients suspicious for disease recurrence after adequate surgical therapy.

Methods

Inclusion criteria were: a) adequate surgical treatment for proven osteosarcoma and documented complete remission after therapy; b) ¹⁸F-FDG-PET/CT performed during follow-up for clinical/diagnostic suspicion of relapse; c) new surgical treatment with excision of the suspected lesions; d) histological validation of ¹⁸F-FDG-PET/CT findings. Thirty-seven patients matching all inclusion criteria were retrospectively enrolled (20 men and 17 female). Primary surgical treatment consists of resection (31 cases) or amputation (six cases). ¹⁸F-FDG-PET/CT performance was assessed with a per-patient and per-site evaluation of sensitivity, specificity, accuracy, positive predicting value (PPV), and negative predicting value (NPV). The sites of relapse were classified as local, lung, lymphnodes (LNs), and distant (other skeletal segments and/or distant soft tissue). The disease-free survival (DFS) and the overall survival (OS) after 18F-FDG PET/CT were evaluated.

Results

¹⁸F-FDG-PET/CT was positive in 89.2% (33/37) of patients. Local uptake only was observed in 35.1% patients (13/37); lung uptake only in 18.9% (7/37); distant uptake only in 2.7% (1/37) case; multiple sites of uptake in 32.4% (12/37). Histology resulted positive in 92% (34/37) of patients. A total of 51 pathologic lesions were evaluated (22 local relapse, 11 lung metastasis, 10 metastatic LNs, eight distant metastatic lesions). On a per-patient analysis ¹⁸F-FDG-PET/CT showed a sensitivity, specificity, accuracy, PPV, and NPV of 91%, 75%, 89%, 97%, 50%. On a per-site analysis the performance for local relapse was 96%, 100%, 97%, 100%, 93%, while for lung relapse detection was 80%, 100%, 92%, 100%, 88%. The mean follow-up after ¹⁸F-FDG-PET/CT was 21.5 months. At the last follow-up, 19% (7/37) of patients were death with disease, 38% (14/37) were alive with disease, and 43% (16/37) had no evidence of disease. Overall survival was 90% and 75% at 24 and 60 months, respectively.

Conclusion

¹⁸F-FDG-PET/CT showed valuable results for detecting recurrence(s) in osteosarcoma patients with suspicious of relapse after treatment, particularly in the detection of local relapse and lung metastasis.

     

^18F-FDG PET／CT显像诊断妇科肿瘤复发、转移的价值

目的探讨^18F-脱氧葡萄糖（FDG）PET／CT显像诊断妇科肿瘤复发、转移的价值,并评价其对临床再分期及治疗决策的影响。方法对47例临床可疑复发、转移的妇科肿瘤患者行^18F—FDG PET／CT显像,对PET、CT及PET／CT图像进行对比分析。采用SPSS12．0软件,对数据行∥检验、校正的,检验及确切概率法分析。结果47例患者中共发现病灶158处,其中恶性病灶149处,良性病灶9处。^18F-FDG PET／CT诊断妇科肿瘤复发、转移的灵敏度、特异性、准确性、阳性预测值及阴性预测值分别为95．97％（143／149）,6／9,94．30％（149／158）,97．95％（143／146）及50．00％（6／12）。PET／CT在诊断妇科肿瘤复发、转移的灵敏度、准确性及阴性预测值方面明显优于单纯CT（χ^2=18．198,18．890,6．825,P均〈0．05）;^18F-FDG PET／CT和单纯PET在各项诊断效能指标间差异无统计学意义（χ^2=0．632,0．000,0．459,0．000,0．150,P均〉0．05）,但PET／CT使33．54％（53／158）的单纯PET无法准确定位的病灶得到了准确定位。同单纯CT及PET相比,PET／CT分别使44．68％（21／47）和31．91％（15／47）的患者TNM分期改变,对T分期的影响最明显;共有19．15％（9／47）的患者临床分期改变,并改变相应的治疗决策。结论^18F—FDG PET／CT显像诊断妇科肿瘤复发、转移准确而全面,对临床再分期及治疗决策有重要影响。     

18F-FDG PET/CT结合高分辨率CT对孤立性肺结节的

 目的 探讨18F-FDG PET/CT显像结合高分辨率CT(high resolution CT,HRCT)对孤立性肺结节(solitary pulmonary nodule,SPN)的诊断价值。方法 回顾性分析124例SPN患者的18F-FDG PET/CT检查资料,其中76例加做HRCT扫描,所有病例经病理或临床随访证实。18F-FDG PET/CT通过目测法和半定量法判断病灶的代谢情况,结合CT或HRCT病灶的形态学特征判断良、恶性。结果 48例仅行18F-FDG PET/CT检查的SPN患者,正确诊断32例为恶性,8例为良性,假阳性与假阴性各4例。76例加做HRCT的患者,正确诊断62例恶性与8例良性,假阳性与假阴性分别为2例和4例。18F-FDG PET/CT 结合HRCT与单纯18F-FDG PET/CT诊断SPN的灵敏度、特异性及准确率分别为94%、80%、90%与89%、67%、83%。结论 18F-FDG PET/CT协同HRCT可提高对SPN性质判断的灵敏度、特异性及准确率。     

超声检查和PET/CT检查诊断甲状腺乳头状癌中央区淋巴结转移的对比研究

目的比较超声检查和18F-FDG PET/CT检查对甲状腺乳头状癌中央区淋巴结转移的诊断价值。方法回顾性分析93例经病理证实的甲状腺乳头状癌患者中央区淋巴结转移情况,与术前超声检查和PET/CT检查对比,评价其诊断甲状腺乳头状癌中央区淋巴结转移的价值。结果超声检查诊断中央区淋巴结转移的敏感度、特异度、准确度、阳性预测值、阴性预测值分别是78.8%、61.0%、71.0%、71.9%、69.4%(χ^2=4.742,P=0.029);PET/CT检查诊断中央区淋巴结转移的敏感度、特异度、准确性、阳性预测值、阴性预测值分别是53.8%、78.0%、64.5%、75.7%、57.1%(χ^2=3.882,P=0.049)。超声检查和PET/CT检查诊断中央区淋巴结转移的ROC曲线下面积(AUC)分别为0.699、0.659。结论超声检查诊断甲状腺乳头状癌中央区淋巴结转移具有较高敏感度和准确性,且因其简便、分辨率高、无辐射等优势,较18F-FDG PET/CT检查更具有显著意义。