全身PET/CT和VEGF-C检查对非小细胞肺癌诊治的应用价值

目的：探讨全身PET/CT和血浆血管内皮生长因子-C（VEGF-C）在非小细胞肺癌（NSCLC）诊断和治疗选择中的临床应用价值。方法：收集2005年1月17日～2007年1月17日86例病理确诊的NSCLC患者的PET/CT资料并留取血清样本备用。比较PET/CT、胸部CT、支气管镜活检及经皮肺穿刺切割活检4种不同方法对NSCLC的诊断敏感性;分析SUV值（standardized uptake value）和延迟相SUV对NSCLC的诊断价值;比较PET/CT与常规检查的TNM分期在淋巴结和远处转移中的检出率和检出分布上的差异。用双抗体夹心ELISA法试剂盒测定血清VEGF-C浓度辅助胸部CT评价N分期。结果：入组研究NSCLC患者86例,男性67例,女性19例;腺癌41例、鳞癌37例、混合型腺癌5例及大细胞癌3例。PET/CT和胸部CT、支气管镜活检、经皮肺穿切割活检术对NSCLC患者肺部原发病变的诊断敏感性分别为90.89%（78/86）、76.47%（60/86）、80%（36/45）和90%（45/50）,PET/CT与胸部CT在诊断敏感性上差异显著（P=0.02）。86例NSCLC患者PET/CT初始相SUV均值为8.27±4.90,其中46例患者延迟相SUV均值为8.35±5.29,高于其初始相SUV均值7.62±4.50（P=0.003）。PET/CT对N1、N2、N3分别检出10、24、26例,合计检出率为69.77%（60/86）;胸部CT/VEGF-C分别检出9、29、6例,合计53.88%（46/86）,PET/CT组与CT/VEGF-C组在阳性检出率和淋巴结分布上差异均非常显著（P=0.006和P=0.004）。本组PET/CT诊断Ⅳ期肺癌38例,与常规检查组诊断29例,两组在阳性发现率上无显著差异（P=0.211）,在分布上两组差异也不显著（P=0.712）。结论：PET/CT对NSCLC原发肿瘤的诊断敏感性显著优于胸部CT,延迟相SUV值对SUV初始值诊断NSCLC有重要参考价值。PET/CT对NSCLC的TNM分期比常规检查分期可能对治疗帮助更大。     

Single photon emission tomography/computed tomography (SPET/CT) and positron emission tomography/computed tomography (PET/CT) to image cancer

Hybrid systems associating the sharpness of anatomic images coming from computed tomography (CT) and radionuclide functional imaging (SPET or PET) are opening a new era in oncology. This multimodal imaging method is now routinely used for the diagnosis, extent, follow up, treatment response and detection of occult disease in different types of malignancies with a significant impact on the treatment strategy leading for a change for more than 68% of all investigated patients.     

Comparison of positron emission tomography (PET) and computed tomography (CT) for better target volume definition in radiation therapy planning

Background  

In cancer patients, positron emission tomography/computed tomography (PET/CT) fused images present less variability in target contouring, respect to use only CT images, respectively. However, the gold standard has not yet been clearly established between radiation oncologists with regard to PET images and the methodology of contouring targets with confidence using PET/CT fused images. The aim of this study was to determine whether integrated PET/CT fused images provide advantages in virtual simulation compared with morphological contouring only with CT.     

The feasibility of prostate-specific membrane antigen positron emission tomography(PSMA PET/CT)-guided radiotherapy in oligometastatic prostate cancer patients

Background

To investigate the efficacy and toxicity of 68Ga-PSMA-HBED-CC (⁶⁸Ga-PSMA) PET-CT-guided RT in the treatment of oligometastatic prostate cancer retrospectively.

Methods

A total of 23 prostate cancer patients with biochemical relapse, of which 13 were castration sensitive (CS) and 10 castration resistant (CR), were treated with intensity-modulated and image-guided RT (IMRT-IGRT) on ≤3 metastases detected by ⁶⁸Ga PSMA PET-CT. Androgen deprivation therapy was continued in CR patients.

Results

A total of 38 metastases were treated. The involved sites were pelvic bone (n = 16), pelvic lymph nodes (n = 11), paraaortic lymph nodes (n = 6), ribs (n = 3) and vertebral body (n = 2). The median PSA prior to RT was 1.1 ng/mL (range 0.1–29.0 ng/mL). A median dose of 43.5 Gy (range 30–64 Gy) was delivered by IMRT-IGRT in 12–27 fractions. At a median follow-up of 7 months (range 2–17 months), 19 patients (83%) were in remission. Four patients (17%) developed distant recurrences. The actuarial 1-year LC, PFS and OS rates were 100, 51 (95% CI 8–83%) and 100%. Univariate analysis demonstrated a statistically significantly better PFS in CS patients as compared to CR patients (1-year PFS 67 vs. 0%, p < 0.01). One patient experienced grade 2 acute gastrointestinal toxicity. Grade 3 or more toxicity events were not observed.

Conclusions

By providing optimal LC, low toxicity and a promising PFS in CS patients, the current retrospective study illustrated that ⁶⁸Ga PSMA PET-CT-guided RT may be an attractive treatment strategy in patients with oligometastatic prostate cancer. Validation by randomized trials is eagerly awaited.

     

正电子发射断层扫描仪PET中的数据校正常用方法

介绍了正电子发射断层扫描（PET）中各种校正的意义及常见算法，这些校正包括归一化校正，衰变校正，散射与衰减校正，活度刻度等。对校正算法的最新进展和PET相关设备中的校正算法也做了些介绍。恰当的校正对提高PET的成象质量及定量分析的准确性非常重要。因此，校正算法是PET设备软件系统中所必不可少的组成部分。     

Radiotherapy treatment planning for patients with non-small cell lung cancer using positron emission tomography (PET).

PURPOSE: Many patients with non-small cell lung cancer (NSCLC) receive external beam radiation therapy as part of their treatment. Three-dimensional conformal radiation therapy (3DCRT) commonly uses computed tomography (CT) to accurately delineate the target lesion and normal tissues. Clinical studies, however, indicate that positron emission tomography (PET) has higher sensitivity than CT in detecting and staging of mediastinal metastases. Imaging with fluoro-2-deoxyglucose (FDG) PET in conjunction with CT, therefore, can improve the accuracy of lesion definition. In this pilot study, we investigated the potential benefits of incorporating PET data into the conventional treatment planning of NSCLC. Case-by-case, we prospectively analyzed planning target volume (PTV) and lung toxicity changes for a cohort of patients. MATERIALS AND METHODS: We have included 11 patients in this study. They were immobilized in the treatment position and CT simulation was performed. Following CT simulation, PET scanning was performed in the treatment position using the same body cast that was produced for CT simulation and treatment. The PTV, along with the gross target volume (GTV) and normal organs, was first delineated using the CT data set. The CT and PET transmission images were then registered in the treatment planning system using either manual or automated methods, leading to consequent registration of the CT and emission images. The PTV was then modified using the registered PET emission images. The modified PTV is seen simultaneously on both CT and PET images, allowing the physician to define the PTV utilizing the information from both data sets. Dose-volume histograms (DVHs) for lesion and normal organs were generated using both CT-based and PET+CT-based treatment plans. RESULTS: For all patients, there was a change in PTV outline based on CT images versus CT/PET fused images. In seven out of 11 cases, we found an increase in PTV volume (average increase of 19%) to incorporate distant nodal disease. Among these patients, the highest normal-tissue complication probability (NTCP) for lung was 22% with combined PET/CT plan and 21% with CT-only plan. In other four patients PTV was decreased an average of 18%. The reduction of PTV in two of these patients was due to excluding atelectasis and trimming the target volume to avoid delivering higher radiation doses to nearby spinal cord or heart. CONCLUSIONS: The incorporation of PET data improves definition of the primary lesion by including positive lymph nodes into the PTV. Thus, the PET data reduces the likelihood of geographic misses and hopefully improves the chance of achieving local control.     

NCCN task force report: positron emission tomography (PET)/computed tomography (CT) scanning in cancer

The use of positron emission tomography (PET) is increasing rapidly in the United States, with the most common use of PET scanning related to oncology. It is especially useful in the staging and management of lymphoma, lung cancer, and colorectal cancer, according to a panel of expert radiologists, surgeons, radiation oncologists, nuclear medicine physicians, medical oncologists, and general internists convened in November 2006 by the National Comprehensive Cancer Network. The Task Force was charged with reviewing existing data and developing clinical recommendations for the use of PET scans in the evaluation and management of breast cancer, colon cancer, non-small cell lung cancer, and lymphoma. This report summarizes the proceedings of this meeting, including discussions of the background of PET, possible future developments, and the role of PET in oncology.     

The impact of positron emission tomography (PET) on expected management during cancer treatment

BACKGROUND:

Positron emission tomography (PET) performed during cancer therapy (treatment monitoring) has shown promise for predicting treatment outcome. However, when used for this purpose, PET generally is not considered standard care. Under the Medicare ‘coverage with evidence development’ policy, PET (and integrated PET/computed tomography) became a covered service for treatment monitoring if prospective registry data were collected.

METHODS:

The National Oncologic PET Registry collected questionnaire data on intended patient management before and after PET. Data were available from 8240 patients who had 10,497 treatment‐monitoring PET scans at 946 centers; these studies were used to monitor chemotherapy alone (82%), radiation therapy alone (6%), or combined‐modality treatment (12%). Ovarian, pancreatic, and lung cancers accounted for 37% of the cohort. In 54% of scans, the pre‐PET summary stage was metastatic disease.

RESULTS:

If PET had not been available, then the pre‐PET plan would have been other imaging (53%), ongoing treatment (41%), or biopsy or watching (6%). Change in the post‐PET intended management was similar in the imaging and treatment groups: 26% to 28% of scans to switching to another therapy, and 16% to 19% scans led to adjustment of the dose or duration of therapy. Changes in management were more frequent if the referring physician judged that the post‐PET prognosis was worse rather than improved or unchanged (78% vs 40%). The physicians indicated that PET enabled 91% of their patients to avoid future tests.

CONCLUSIONS:

Physicians often report plans to modify their therapeutic plans in elderly cancer patients when PET is used for treatment monitoring. Cancer 2009. © 2009 American Cancer Society.     

Comparison of meta-analyses among elastosonography (ES) and positron emission tomography/computed tomography (PET/CT) imaging techniques in the application of prostate cancer diagnosis

Tumor Biology - The early diagnosis of prostate cancer (PCa) appears to be of vital significance for the provision of appropriate treatment programs. Even though several sophisticated imaging...     

Evaluation of pulmonary nodules and lung cancer with one‐inch crystal gamma coincidence positron emission tomography/CT versus dedicated positron emission tomography/CT

Dedicated positron emission tomography (PET)/CT scanners using BGO and related detectors (d‐PET) have become standard imaging instruments in many malignancies. Hybrid gamma camera systems using NaI detectors in coincidence mode (g‐PET) have been compared to d‐PET but reported usefulness has been variable when gamma cameras with half‐inch to three‐fourth‐inch thick crystals have been used without CT. Our aim was to compare g‐PET with a 1‐in.‐thick crystal and inbuilt CT for lesion localization and attenuation correction (g‐PET/CT) and d‐PET/CT in patients presenting with potential and confirmed lung malignancies. One hour after ¹⁸F‐fluorodeoxyglucose (FDG), patients underwent BGO d‐PET/CT from jaw to proximal thigh. This was followed by one to two bed position g‐PET/CT 194 ± 27 min after FDG. Each study pair was independently analysed with concurrent CT. d‐PET/CT was interpreted by a radiologist experienced in both PET and CT, and g‐PET/CT by consensus reading of an experienced PET physician and an experienced CT radiologist. A TNM score was assigned and studies were then unblinded and compared. Fifty‐seven patients underwent 58 scan pairs over 2 years. Eighty‐nine per cent concordance was shown between g‐PET/CT and d‐PET/CT for the assessment of intrapulmonary lesions, with 100% concordance for intrapulmonary lesions >10 mm (36 of 36). Eighty‐eight per cent (51 of 58) concordance was shown between g‐PET/CT and d‐PET/CT for TNM staging. Coincidence imaging using an optimized dual‐head 1‐in.‐thick crystal gamma camera with inbuilt CT compares reasonably well with dedicated PET/CT for evaluation of indeterminate pulmonary lesions and staging of pulmonary malignancies and may be of some value when d‐PET/CT is not readily available.     

Brain tumor protein synthesis and histological grades: A study by positron emission tomography (PET) with C11-L-Methionine

Summary Brain protein synthesis may be evaluated in vivo by a PET three compartment methionine model. 14 human brain tumor patients were studied. Protein synthesis rate (PSR) was increased in any glial tumor even in low grades, but this increase was statistically more important in anaplastic tumor.Radiotherapy action was evaluated in two patients. Local tumoral PSR was reduced to normal brain PSR after treatment. No difference was seen in normal cortex contralateral to the lesion between pre and post radiotherapy examination.11 C-L-Methionine incorporation measured by PET looks as a very sensitive method for studying tumor metabolism and treatment effects.     

Imaging of biological character of cancer using positron emission tomography(PET)

There are two types of radiopharmaceuticals for cancer imaging with PET. The first target is a marker of cancer proliferation, and positron-labeled analogs of glucose, amino acid, and nucleic acid are commonly used for this purpose. 18F-FDG is a typical tracer of this approach. The second target is visualization of cancer-specific biological characters. In Tohoku University, we developed 18F-fluorodeoxygalactose(18F-FDGal), 18F-SAV03M, and 18F-FRP170 as tracers of the second category. 18F-FDGal is metabolized and trapped in the tissue by liver-specific galactose metabolic enzymes. It is used for detecting well-differentiated hepatocellular carcinoma which originated from liver cells and still maintains the enzymes. 18F-SAV03M is a substrate for matrix metalloproteinase-2 and was developed for the visualization of tumor invasiveness. 18F-FRP170 was developed for the visualization of hypoxic cancer cells which cause radiotherapy and chemotherapy resistance. In addition, the uses of labeled antisense oligonucleotide and aptamers were introduced for the visualization of specific mRNA and proteins expression.     

Clinical utility of integrated positron emission tomography/computed tomography imaging in the clinical management and radiation treatment planning of locally advanced rectal cancer

PurposeThe role of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT) in the staging and radiation treatment planning of locally advanced rectal cancer is ill defined. We studied the role of integrated PET/CT in the staging, radiation treatment planning, and use as an imaging biomarker in rectal cancer patients undergoing multimodality treatment.Methods and materialsThirty-four consecutive patients with T3-4N0-2M0-1 rectal adenocarcinoma underwent FDG-PET/CT scanning for staging and radiation treatment planning. Planned clinical management was compared before and after the addition of PET/CT information. Three radiation oncologists independently delineated CT-based gross tumor volumes (GTVCT) using clinical information and CT imaging data, as well as gradient autosegmented PET/CT-based GTVs (GTV_PETCT). The mean GTV, interobserver concordance index (CCI), and proximal and distal margins were compared. The maximal standardized uptake value (SUVmax), metabolic tumor volume (MTV), and dual-time point PET parameters were correlated with clinicopathologic endpoints.ResultsClinical management was altered by PET/CT in 18% (n = 6) of patients with clinical upstaging in 6 patients and radiation treatment planning altered in 5 patients. Of the 30 evaluable preoperative patients, the mean GTV_PETCT was significantly smaller than the mean GTV_CT volumes: 88.1 versus 102.8 cc (P = .03). PET/CT significantly increased interobserver CCI in contouring GTV compared with CT only-based contouring: 0.56 versus 0.38 (P < .001). The proximal and distal margins were altered by a mean of 0.4 ± 0.24 cm and −0.25 ± 0.18 cm, respectively. MTV was inversely associated with 2-year progression-free survival (PFS) and overall survival (OS): smaller MTVs (< 33 cc) had superior 2-year PFS (86% vs 60%, P = .04) and OS (100% vs 45%, P < .01) compared with larger MTVs (> 33 cc). SUVmax and dual-time point PET parameters did not correlate with any endpoints.ConclusionsFDG-PET/CT imaging impacts overall clinical management and is useful in the radiation treatment planning of rectal cancer patients by decreasing interobserver variability in contouring target boost volumes. Pretreatment MTV may provide useful prognostic information and requires further study.     

18F-FDG-PET在妊娠绒毛膜癌临床诊疗中的应用

目的 探讨18F-脱氧葡萄糖正电子发射显影／电子计算机断层扫描成像（18F-FDG-PET）在妊娠绒毛膜癌临床诊疗中的应用价值。方法 对2例妊娠绒毛膜癌患者多次同时行18F-FDG-PET检查与动态血绒毛膜促性腺激素（β-HCG）监测,分析双肺、肝脏及盆腔的代谢异常增高转移性病变情况。结果 1例患者发现双肺、肝脏及盆腔多处转移病灶,经EMA-CO方案化疗后动态血β-HCG渐转正常,18F-FDG-PET显示多处病灶趋渐转阴。另1例经化疗后复发,18F-FDG-PET显示原发癌灶无活性,但血β-HCG稍增高,行子宫全切除术,病理诊断提示妊娠绒毛膜癌,活性细胞存在,判定18F-FDG-PET呈假阴性。术后持续随访,血β-HCG均为阴性。结论 18F-FDG-PET在妊娠绒毛膜癌临床诊疗中了解原发灶与转移灶特点,评估癌细胞活性具有较高的应用价值。结合血β-HCG监测,可降低18F-FDG-PET假阳性和假阴性,为临床上妊娠绒毛膜癌的诊疗提供可靠依据。     

18F]FDG positron emission tomography/computed tomography and multidetector computed tomography roles in thymic lesion treatment planning

RATIONALE: Thymic masses may represent an unsolved diagnostic problem which often require surgical procedures for an accurate staging. A non-invasive way to determine the nature of thymic lesions would help identify the patients which are true candidates for surgery. Our retrospective study aims to assess multidetector computed tomography and 2-[(18)F]fluoro-2-deoxyglucose positron emission tomography/computed tomography ([(18)F]FDG-PET/CT) capacity to distinguish benign from malignant thymic lesions. METHODS: Helical multidetector CT (MDCT) and [(18)F]FDG-PET/CT of twenty consecutive patients presenting with a thymic mass at our Institute were retrospectively analyzed. MDCT scans were focused on morphologic features and invasiveness characteristics. Qualitative and semi-quantitative analyses by maximum standardized uptake value corrected for body weight (SUVbw max) were performed on [(18)F]FDG-PET/CT. In all cases, readers were blinded to pathology findings. Both imaging techniques were correlated to final pathology. Student's t-test was performed on SUVbw max stratified for thymic epithelial tumors. RESULTS: In the group of benign lesions MDCT correctly identified well-defined margins of masses in 8 out of 8 patients whereas [(18)F]FDG-PET/CT was negative in 7 out of 8 patients. Among malignant lesions MDCT revealed mediastinum fat or infiltration of adjacent organs in 10/12 patients. On the other hand [(18)F]FDG-PET/CT showed increased radiotracer uptake in 12/12 patients. CONCLUSIONS: MDCT and [(18)F]FDG-PET/CT alone are not able to differentiate the nature of thymic lesions. However, they are two non-invasive complementary techniques which can be used to differentiate benign from high-risk malignant thymic lesions. These findings should be taken into account before surgery is performed as a diagnostic procedure.     

Early positron emission tomography (PET) restaging: a predictive final response in Hodgkin's disease patients.

BACKGROUND: It is important to distinguish between responders to standard treatment and non-responders Hodgkin's disease (HD) patients. PATIENTS AND METHODS: Between June 2003-September 2004, in our institute, 40 newly-diagnosed patients with advanced stage HD were consecutively treated with ABVD chemotherapy for six cycles. All these patients underwent staging/restaging: computed tomography (CT) and positron emission tomography (PET) at time 0, PET after two cycles, CT and PET after four and six cycles. RESULTS: After two cycles (PET-2), the PET was negative in 28/40 (70%), positive in 8/40 (20%), and minimal residual uptake (MRU) was present in the remaining four (10%) patients. After treatment, among eight patients who were PET-2+, seven showed refractory disease and one had relapse after 3 months. All four patients with MRU at the PET-2 became PET- during the further four cycles and, after treatment, three were in complete response (CR) and one relapsed after 5 months. All 28 PET negative patients at the PET-2 remained PET negative and all of them were in CR after treatment. CONCLUSIONS: The PET use for early (after two cycles) response assessment in HD patients is a significant step forward and has the potential to help physicians make crucial decisions about further treatment.