Positron-emission tomography as a prognostic tool for early-stage lung cancer

BACKGROUND: Positron-emission tomography (PET) shows tissue metabolic activity in the form of the standard uptake value (SUV). This study examines the prognostic value of the SUV for early-stage lung cancer. METHODS: A retrospective review of 187 patients undergoing PET for potential lung cancer. Data collected included patient demographics, tumor pathology, and survival information. Data were correlated with PET results to determine if a prognostic relationship exists. RESULTS: The sensitivity and specificity of PET for detecting malignant lesions were 98% and 24%. Malignant lesions had a higher SUV than benign lesions (5.9 +/- 6.2 versus 2.2 +/- 1.8, P < .0001). The average SUV of well-differentiated tumors was 2.6 +/- 3.1 versus 5.9 +/- 5.5 for other tumors (P = .010). There was a strong correlation between tumor stage and SUV (analysis of variance, P < .0001). There was no difference in tumor SUV for survivors versus nonsurvivors. CONCLUSIONS: The SUV correlates with prognostic indicators, such as tumor stage and grade. The SUV alone was not an independent predictor of survival.     

The role of [<Superscript>18</Superscript>F] FDG-PET,CT/MRI and tumor marker kinetics in the evaluation of postchemotherapy residual masses in metastatic germ cell tumors—prospects for management

The purpose of this study was to assess the ability of [¹⁸F]FDG-PET, CT/MRI and serum tumor marker (TM) to predict the viability of residual masses after high-dose chemotherapy (HD-Ctx) in patients with metastatic germ cell tumors (GCT). In a prospective study, 60 residual tumors in 28 GCT patients were classified as viable/nonviable by FDG-PET, CT/MRI and TM levels. The results were validated either by histological examination of a resected mass and/or biopsy or by clinical/radiological follow-up for at least 6 months. There were no significant differences among the sensitivities observed with PET, CT/MRI and TM, but PET was significantly more specific than CT/MRI in predicting residual mass viability. TM showed the highest specificity. The highest accuracy in classification of residual tumors was achieved by a combination of PET, CT/MRI and TM (area under the ROC curve =0.91). All mature teratomas showed false-negative PET results with SUVs in the same range as necrosis. For classification of residual masses after HD-Ctx of metastatic GCT, [¹⁸F]FDG-PET is a valuable diagnostic method to complement the established procedures CT and TM. Positive PET results are highly correlated with the presence of viable tumor, but residual masses with negative PET findings still require resection. In cases of tumor progression diagnosed by CT and elevated TM, additional PET examinations are without benefit. PET seems useful in patients with stable disease or partial remission in CT/MRI and normalized TM as well as in marker-negative disease.     

Quantitative in vivo assessment of bone allograft viability using 18F-fluoride PET/CT after glenoid augmentation in reverse shoulder arthroplasty: a pilot study

Background

Success after glenoid bone augmentation in total shoulder arthroplasty depends on osseous integration and non-resorption. Standard imaging techniques, such as computed tomography (CT) and X-rays, cannot quantify bone viability. Therefore, we introduce a new technique to assess graft viability using ¹⁸F-sodium fluoride (¹⁸F-NaF) PET–CT for femoral allografts in reverse total shoulder arthroplasty (RSA).

Materials and methods

Patient charts were reviewed following glenoid augmentation using femoral allografts in reverse total shoulder arthroplasty. A total of seven patients were included in this study. ¹⁸F-NaF PET–CT was used to assess graft viability and graft fusion. Semiquantitative assessment of ¹⁸F-NaF uptake was performed by means of a standardized uptake value (SUV). Radiographs were used to assess fusion. The mean age of the patients at the time of follow-up was 83.4 years (range 79–92), and the mean follow-up was 44.4 months.

Results

Viability and fusion were confirmed in all allografts using semiquantitative analysis of ¹⁸F-NaF PET–CT by means of standardized uptake value (SUVmax). Metabolic activity of medullary region of a vertebral spine was defined as a reference background. The mean value of maximum tracer activity in the allograft was not statistically different from native bone in the reference vertebrae (p = 0.14).

Conclusions

¹⁸F-NaF PET–CT is a practicable tool to quantitatively assess viability in large bone allografts after glenoid augmentation in RSA. The study shows viability and fusion in all allografts.

Level of Evidence

Level IV, treatment study.

     

Preoperative FDG-PET for axillary metastases in patients with breast cancer

HYPOTHESIS: Fludeoxyglucose F 18 (FDG) positron emission tomography (PET) can be used to predict axillary node metastases. DESIGN: Case series. SETTING: Comprehensive breast care center. PATIENTS: Fifty-one women with 54 biopsy-proven invasive breast cancers. INTERVENTION: Whole-body FDG-PET performed before axillary surgery and interpreted blindly. MAIN OUTCOME MEASURES: Axillary FDG activity, quantified by standardized uptake value (SUV); axillary metastases, quantified histologically; and tumor characteristics. RESULTS: There was PET activity in 32 axillae (59%). The SUVs ranged from 0.7 to 11.0. Twenty tumors had an SUV of 2.3 or greater, and 34 had an SUV of less than 2.3. There were no significant differences between these 2 groups except in axillary metastasis size (SUV /=2.3): mean age, 53 vs 58 years (P = .90); mean modified Bloom-Richardson score, 7.7 vs 7.6 (P = .20); lymphovascular invasion present, 25% vs 36% (P = .40); mean Ki-67 level, 25% vs 32% (P = .20); mean tumor size, 2.9 vs 3.2 cm (P = .05); and axillary metastasis size, 0.9 vs 1.7 (P = .001). By adopting an SUV threshold of 2.3, FDG-PET had a sensitivity of 60%, a specificity of 100%, and a positive predictive value of 100%. CONCLUSIONS: Patients with an SUV greater than 2.3 had axillary metastases. This finding obviates the need for sentinel lymph node biopsy or needle biopsy to diagnose axillary involvement. Surgeons can proceed to axillary node dissection to assess the number of nodes involved, eliminate axillary disease, or perhaps provide a survival benefit if preoperative FDG-PET has an SUV greater than 2.3.     

Experimental study of pulmonary artery infusion with cisplatin in a solitary pulmonary tumor model using a rat colorectal adenocarcinoma cell line

OBJECTIVES: We assessed a tumor model prepared by open lung injection to study metastatic lung tumors, and evaluated the efficacy of pulmonary artery infusion. METHODS: Subjects were 30 male F344 rats. In experiment 1, we evaluated chemosensitivity of a rat colorectal adenocarcinoma cell line (RCN-9) using a colorimetric [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. In experiment 2, we injected RCN-9 cells into the left lung on day 0; on day 10, we measured tumor tissue blood flow before and after pulmonary arterial occlusion. In experiment 3, we injected RCN-9 cells into the left lung and conducted no further procedures in controls. The pulmonary artery infusion group underwent pulmonary artery infusion with 0.1 mg of cisplatin on day 3 and the sham group injection with saline solution alone. On day 10, rats were sacrificed and maximum tumor cross-section measured. RESULTS: In experiment 1, the drug concentration required to inhibit cell growth 50% was 2.45 x 10(-6) M. In experiment 2, tumor tissue blood flow decreased significantly after arterial occlusion (p = 0.003). In experiment 3, the maximum tumor cross-section in the pulmonary artery infusion group was significantly smaller than in shams (p = 0.0027) and controls (p = 0.0019). CONCLUSIONS: The pulmonary artery supplies tumors with blood, so this model appears useful in studying metastatic lung tumors, whose size was reduced significantly by pulmonary artery infusion with cisplatin. Pulmonary artery infusion is thus a promising modality in metastatic lung tumor treatment.     

18F-NaF PET/CT IMAGING IN FIBROUS DYSPLASIA OF BONE

Fibrous dysplasia (FD) is a mosaic skeletal disorder resulting in fractures, deformity, and functional impairment. Clinical evaluation has been limited by a lack of surrogate endpoints capable of quantitating disease activity. The purpose of this study was to investigate the utility of ¹⁸F-NaF PET/CT imaging in quantifying disease activity in patients with FD. Fifteen consecutively evaluated subjects underwent whole-body ¹⁸F-NaF PET/CT scans, and FD burden was assessed by quantifying FD-related ¹⁸F-NaF activity. ¹⁸F-NaF PET/CT parameters obtained included (i) SUV_max (standardized uptake value [SUV] of the FD lesion with the highest uptake); (ii) SUV_mean (average SUV of all ¹⁸F-NaF–positive FD lesions); (iii) total volume of all ¹⁸F-NaF–positive FD lesions (TV); and (iv) total FD lesion activity determined as the product of TV multiplied by SUV_mean (TA = TV × SUV_mean) (TA). Skeletal outcomes, functional outcomes, and bone turnover markers were correlated with ¹⁸F-NaF PET/CT parameters. TV and TA of extracranial FD lesions correlated strongly with skeletal outcomes including fractures and surgeries (p values ≤ 0.003). Subjects with impaired ambulation and scoliosis had significantly higher TV and TA values (P < 0.05), obtained from extracranial and spinal lesions, respectively. Craniofacial surgeries correlated with TV and TA of skull FD lesions (P < 0.001). Bone turnover markers, including alkaline phosphatase, N-telopeptides, and osteocalcin, were strongly correlated with TV and TA (P < 0.05) extracted from FD lesions in the entire skeleton. No associations were identified with SUV_max or SUV_mean. Bone pain and age did not correlate with ¹⁸F-NaF PET/CT parameters. FD burden evaluated by ¹⁸F-NaF-PET/CT facilitates accurate assessment of FD activity, and correlates quantitatively with clinically-relevant skeletal outcomes. © 2019 American Society for Bone and Mineral Research.     

18-fluorodeoxyglucose positron emission tomography in predicting survival of patients with pancreatic carcinoma

The prediction of survival of patients with pancreatic cancer is usually based on tumor staging and grading and on the level of tumor markers. However, accurate tumor staging can be obtained only after resection, and still there is a great difference in survival rates among patients with the same clinicopathologic parameters. Recently the uptake of 18-fluorodeoxyglucose (FDG) by positron emission tomography (PET) has been found to be correlated with survival in patients with pancreatic cancer. This study evaluated the role of ¹⁸FDG PET as a prognostic factor for patients with pancreatic cancer. From June 1996 to July 2002, a total of 118 patients underwent PET for pancreatic cancer. The standardized uptake value (SUV) of ¹⁸FDG was calculated in 60 of them, and these patients were divided into high (>4) and low (≦4) SUV groups. They were also evaluated according to the tumor node metastasis (TNM) classification system of the International Union Against Cancer, and by tumor grade, medical or surgical treatment, diabetes, age, sex, and CA19-9 serum levels. Twenty-nine cancers showed high and 31 showed low SUVs. Survival was significantly influenced by tumor stage (P = 0.0001), tumor grade (P = 0.01), and SUV (P = 0.005). Multivariate analysis showed that only stage (P = 0.001) and SUV (P = 0.0002)were independent predictors of survival. When patients who were analyzed for SUV were stratified according to the other variables, FDG uptake was related to survival also after stratification for the following: stage III to IVa (P = 0.002), stage IVb (P = 0.01), tumor resection (P = 0.006), moderately differentiated tumors (P = 0.01), age less than 65 years (P = 0.006), CA 19–9 levels greater than 300 kU/L (P = 0.002), and absence of diabetes (P = 0.0001). The SUV calculated with ¹⁸FDG PET is an important prognostic factor for patients with pancreatic cancer and may be useful in selecting patients for therapeutic management. Presented at the Forty-Fourth Annual Meeting of The Society for Surgery of the Alimentary Tract, Orlando, Florida, May 17–22, 2003 (oral presentation); and the Sixth National Congress of the Italian Association of Nuclear Medicine, Genoa, Italy, November 15–19, 2002.     

Using fluorodeoxythymidine to monitor anti-EGFR inhibitor therapy in squamous cell carcinoma xenografts

BACKGROUND: 3'-18F-fluoro-3'-deoxy-fluorothymidine (18F-FLT), a nucleoside analog, could monitor effects of molecularly targeted therapeutics on tumor proliferation. METHODS: We tested whether (18)F-FLT positron emission tomography (PET) uptake changes are associated with antitumor effects of erlotinib in A431 xenografts or cetuximab in SCC1 xenografts. RESULTS: Compared with pretreatment FLT PET scans, 3 days of erlotinib in A431 reduced the standardized uptake value (SUV) by 18%, whereas placebo increased SUV by 1% (p = .005). One week of cetuximab in SCC1 reduced SUV by 62%, whereas placebo reduced SUV by 16% (p = .005). FLT uptake suppression following anti-epidermal growth factor receptor (EGFR) treatment was associated with reduced tumor thymidine kinase-1 (TK1) activity. In vitro TK1 knockdown studies confirmed the importance of TK1 activity on intracellular FLT accumulation suppression. CONCLUSIONS: 18F-FLT PET imaging detects tumor responses to EGFR-inhibitors within days of starting therapy. This technique may identify patients likely to benefit from EGFR-inhibitors early in their treatment course.     

Tomografia por emissão de pósitrons com FDG‐18F na avaliação de pacientes com artrite reumatoide – revisão sistemática

IntroductionRheumatoid arthritis (RA) is a disease characterized by inflammation of the synovial membrane. Several authors have investigated the role of positron emission tomography (PET) with fluorine‐18 fluorodeoxyglucose (¹⁸F‐FDG) in RA.ObjectivesTo systematically review the current literature on the role of ¹⁸F‐FDG PET in the diagnosis, determination of disease activity and assessment of treatment response in patients with RA.MethodsSearches were conducted in Medline, Cochrane Library, Lilacs, Pubmed and Scopus in Portuguese, English and Spanish languages, using the keywords «rheumatoid arthritis», «synovitis», «FDG», «PET», «glycolytic metabolism» and «disease activity».Results142o articles were initially identified, of which only 40 were related directly to the subject. Twelve original articles and three case reports that met the inclusion criteria were selected.DiscussionThe presence of activated macrophages and fibroblasts in pannus are responsible for the intense periarticular uptake of ¹⁸F‐FDG. The uptake patterns do not allow the differential diagnosis with other arthritides. The uptake intensity and the number of joints involved are metabolic parameters of disease activity that correlate well with the composite indices. Longitudinal studies of PET have proven useful in assessing the response to treatment with anti‐TNF. When performed early, PET can predict the therapeutic response.ConclusionAlthough the actual role of this new technique for the investigation of RA is not yet established, ¹⁸F‐FDG PET is a promising tool in determining the activity and prediction of response to treatment of patients with RA.     

Positron emission tomography (PET) in the urooncological evaluation of the small pelvis

Positron emission tomography (PET) with the use of (¹⁸F)2-fluoro-d-2-desoxyglucose (FDG) has been investigated to be a highly sensitive and specific imaging modality in the diagnostic of primary and recurrent tumors and in the control of therapies in numerous non-urologic cancers. The aim of this review is to validate the significance of PET as a diagnostic tool in malignant urological tumors of the small pelvis. A systematic review of the current literature concerning the role of PET for malignant prostate, testicular and bladder tumors was carried out. The data indicate no additional role for PET in comparison with conventional imaging in tumor detection and local staging for prostate, bladder or testicular cancer. Tumor recurrence in prostate cancer seems to be more effectively identified with acetate and choline than with FDG, but this effect is more pronounced with higher PSA values. The value of PET in the identification of metastatic disease in either tumor entity can not be finally outlined as the clinical data are partly missing, controversial or in the process of evaluation. FDG-PET can be regarded as accepted imaging modality in the restaging of seminomatous germ cell tumors after chemotherapy.     

Expression and prognostic value of proliferating cell nuclear antigen in transitional cell carcinoma of the urinary bladder

Forty-eight patients with transitional cell carcinima (TCC) of the bladder were investigated. Routine paraffin-embedded sections were stained with proliferating cell nuclear antigen (PCNA) monoclonal antibody in order to determine the growth fraction of the bladder tumors and to correlate this with tumor grade, stage, development of recurrence and survival rate during follow-up. PCNA positive staining was detected in 95.8% (46/48) of the tumors. The mean labeling index (LI) of superficial tumors (Ta-1,n = 28) was 12.58 ± 12.33%, and 34.55 ± 21.89% in invasive tumors (T2-4,n = 18). A similar correlation was found in association with tumor grade. The patients were followed up for a mean of 4.9 years (range 1–14 years). The mean PCNA Ll in nonrecurrent (n = 21) and simple recurrent (n = 7) superficial tumors was 11.29 ± 11.79% and 16.44 ± 14.05%, respectively, the difference not being statistically significant. To access survival, tumors with a PCNA LI above and below the median level (21%) were compared. Those patients (n = 19) with an index of > 21% (the mean of all the PCNA values) had a worse prognosis than those (n = 27) with an index of < 21%, a difference which is statistically significant. These results suggest that PCNA LI in bladder cancer may prove to be an objective and quantitative assay of biological aggressiveness and provide significant prognostic information, although it does not help the selection of patients at risk of simple recurrence in superficial tumors.     

特殊示踪剂正电子发射体层显像在肺部病变诊断中的应用

目的 探讨胆碱、甲硫氨酸、脱氧胸腺嘧啶核苷、乙酸盐为示踪剂的正电子发射体层显像(PET)在肺部病变诊断中的应用价值.方法 2002年6月至2007年6月对100例肺部占位病变的患者行PET检查.其中~(11)C-胆碱(CH)-PET检查58例,~(11)C-甲硫氨酸(MET)-PET检查16例,~(18)F-脱氧胸腺嘧啶核苷(FLT)-PET检查22例,~(11)C-乙酸盐(AC)-PET检查4例.结果 采用目测法判读,半定量分析法测量病变标准摄取值,结果与病理诊断及随访结果对照.结果CH-PET定性诊断灵敏度、特异度、符合率分别为84.2%(32/38)、57.9%(11/19)、75.4%(43/57).MET-PET定性诊断灵敏度、特异度、符合率分别为6/7、6/9、75.0%(12/16).FLT-PET检查定性诊断灵敏度、特异度、符合率分别为85.7%(12/14)、2/8、63.6%(14/22).CH.PET、MET-PET及FLT-PET中肿瘤标准摄取值与肿瘤大小、患者年龄不相关.AC.PET检查仅1例透明细胞癌肺转移显影,2例鳞状细胞癌、1例腺癌没有显影.结论 这些示踪剂PET对肺部病变的定性诊断有帮助,但存在假阳性和假阴性结果.     

Peptide receptor radionuclide therapy of neuroendocrine tumors with 90Y-DOTATOC: Is treatment response predictable by pre-therapeutic uptake of 68Ga-DOTATOC?

PurposePET with ⁶⁸Ga-DOTATOC allows for imaging and quantitative assessment of somatostatin receptor expression in neuroendocrine tumors (NET). The aim of this retrospective study was to analyze whether pre-therapeutic ⁶⁸Ga-DOTATOC PET/CT is able to predict response to Peptide Receptor Radionuclide Therapy (PRRT).Patients and methodsForty patients with advanced stage NET were treated with a fixed dose of ⁹⁰Y-DOTATOC (5550 or 3700 MBq). Prior to PRRT, each patient received ⁶⁸Ga-DOTATOC PET/CT. Treatment results were evaluated after 3 months by CT, tumor marker levels and clinical course and correlated with ⁶⁸Ga-DOTATOC uptake (SUVmax) and the assumed uptake of ⁹⁰Y-DOTATOC in tumor manifestations (MBq/g). ROC analysis and pairwise comparison of area under the curve (AUC) were performed with pre-treatment uptake of ⁶⁸Ga-DOTATOC, assumed uptake of ⁹⁰Y-DOTATOC and treatment activity alone and in relation to body weight as continuous variables, and response/no response as classification variable.ResultsAccording to conventional criteria (tumor shrinkage, decrease of tumor markers, improved or stable clinical condition), 20 patients were classified as responders, 16 as non-responders and in four patients findings were equivocal. Using a SUV more than 17.9 as cut-off for favorable outcome, PET was able to predict treatment response of all responders and 15 out of 16 non-responders. All four patients with equivocal findings showed SUV less than or equal to 17.9 and soon experienced tumor progression. The assumed uptake of ⁹⁰Y-DOTATOC in tumor manifestations using a cut-off more than 1.26 MBq/g as predictor of response was able to correctly classify 19 out of 20 responders, and 14 out of 16 non-responders. In all patients with equivocal findings, the assumed uptake of ⁹⁰Y-DOTATOC was below 1.26 MBq/g.ConclusionPre-therapeutic ⁶⁸Ga-DOTATOC tumor uptake as well as assumed uptake of ⁹⁰Y-DOTATOC are strongly associated with the results of subsequent PRRT. The defined cut-off values should be confirmed by prospective studies and may then provide the rationale for individual dosing and selecting patients with high likelihood of favorable treatment outcome.     

膀胱移行细胞癌增殖细胞核抗原表达的研究

采用免疫组化ＬＳＡＢ法对４８例膀胱移行细胞癌增殖细胞核抗原（ＰＣＮＡ）进行检测，发现ＰＣＮＡ增殖指数随肿瘤分级的升高而增高，浸润生长肿瘤ＰＣＮＡ增殖指数明显高于乳头状生长者（Ｐ＜０．００１），ＰＣＮＡ高表达组（增殖指数＞５０％）预后明显差于ＰＣＮＡ低表达组（增殖指数≤５０％）。结果表明ＰＣＮＡ可作为膀胱移行细胞癌恶性程度及预后指标之一。     

FDG-PET for evaluating musculoskeletal tumors: a review

 Positron-emission tomography (PET) can provide an in vivo method for evaluating metabolism and physiology in normal and diseased tissues. Clinical trials with [¹⁸F]2-deoxy-2-fluoro-d-glucose (FDG), the most commonly used radiolabeled tracer for PET imaging, have demonstrated increased accumulation of FDG in several cancer tissues. In this article, we introduce the basic principles of FDG-PET and review current knowledge about FDG-PET for evaluating musculoskeletal tumors. Recent reports and our own experience suggest that FDG-PET cannot be a screening method for differential diagnosis between benign and malignant musculoskeletal lesions, including many neoplasms originating from different tissues altogether. FDG-PET might not accurately reflect the malignant potential of musculoskeletal tumors, but rather might implicate cellular components included in the lesions. A high accumulation of FDG can be observed in histiocytic, fibroblastic, and some neurogenic lesions, regardless of whether they are benign or malignant. More specific uses of FDG-PET, such as grading, staging, and monitoring of musculoskeletal sarcomas, should be considered for each tumor of a different histologic subtype. Received: October 2, 2001 RID="*"     

Noninvasive Differential Diagnosis of Pulmonary Nodules Using the Standardized Uptake Value Index

Objectives: We previously showed that the standardized uptake value (SUV) index, which was defined as the ratio of the maximum SUV of the tumor to mean SUV of the liver, was a surrogate marker of lung cancer aggressiveness. In this study of patients with pulmonary nodules (PNs), we explored whether the SUV index could be used to differentiate small malignant from small benign PNsMethods: A total of 284 patients with solitary PNs ≤2 cm in size underwent positron emission tomography/computed tomography and surgery. The associations between pathological findings and clinical factors were evaluated.Results: The median SUV indices of lung cancer, metastatic PNs and benign nodules were 1.2, 1.5, and 0.6, respectively (P <0.01). A SUV index cut-off value of 1.2 was used to differentiate benign from malignant nodules. When patients were grouped according to SUV index cut-off values of <1.2 or ≥1.2, the following cases were false-negative: lung adenocarcinoma (P <0.01), kidney as primary site (P <0.01), and metastatic PNs with long disease-free survival (P = 0.02).Conclusions: As a noninvasive diagnostic marker, the SUV index was found to be useful for differentiating benign from malignant small PNs.     

18Fluorine-fluorodeoxyglucose positron emission tomography/computed tomography total glycolytic volume in thymic epithelial neoplasms evaluation: a reproducible image biomarker

Introduction

¹⁸Fluorine-fluorodeoxyglucose positron emission tomography/computed tomography is not yet accepted as a standard pretreatment evaluation of thymic epithelial neoplasm (TEN). Statistical correlation between standardized uptake value of tumor/mediastinum ratio and patients’ WHO risk class has been reported. PET metabolic tumor volume (MTV) and total glycolytic volume (TGV) have been reported as additional prognostic imaging biomarkers in several human tumors. Purpose of study was to establish whether MTV and TGV add prognostic information in TEN.

Materials and methods

A retrospective dynamic cohort study of prospectively collected data (2006–2012) on 23 consecutive patients with pathologically proven TEN (no thymic carcinoma) was conducted. All patients underwent chest CT, and PET for staging. SUV T/M ratio, semi-quantitative and volumetric analyses of TEN were calculated. Patients were categorized according to WHO classification (low-risk and high-risk thymomas). Statistical analysis was performed with bootstrap method. Multi-collinearity was established using Pearson correlation coefficient. Cut-off point for TGV was compared using Mantel Cox log rank test.

Results

SUV T/M ratio, MTV, and TGV correlate with low- and high-risk TEN. However, the statistical correlation between TGV and WHO classification (ρ = 0.897) was higher than SUV T/M ratio (ρ = 0.873). Since sample distributions were not uniformly smooth, only one cut-off value was identified: a TGV of 383 served as a cut-off value between low-risk and high-risk TEN.

Conclusion

TGV is a PET reproducible imaging marker in patients with TEN, provides prognostic information, and could be useful in pretreatment stratification of patients. Nevertheless, it needs validation in larger cohort studies.     

Proliferative activity of osteosarcoma cells: comparison of osteoblastic and nonosteoblastic regions

There are two opinions regarding malignancy evaluation by location for osteoblastic osteosarcoma: One is that the nonosteoblastic region is undifferentiated and the degree of malignancy is high; the other is that the osteoblastic region sometimes shows a marked chemotherapy effect, so the degree of biological malignancy is higher. To clarify this point, we compared and examined the difference in growth ability at intratumoral locations within the same tumor using proliferating cell nuclear antigen (PCNA) immunohistochemical staining and argyrophilic nucleolar organizer regions (AgNORs) staining. The subjects were 10 patients with osteoblastic osteosarcoma at the distal region of the femur. Specimens obtained during surgery were stained with PCNA and AgNORs, after which about 2400 tumor cells were counted per field of view, respectively. In all patients, the nonosteoblastic region showed a higher value than the osteoblastic region for both the PCNA labeling index and AgNORs number. A positive correlation was observed between the PCNA labeling index and the AgNORs number. Both the PCNA-labeling index and AgNORs number in the metastatic foci were higher than in the primary lesions. There are differences in proliferative ability in the intratumoral locations within the same osteoblastic osteosarcoma. Moreover, there are differences in proliferative ability between the metastatic foci and the primary lesion.     

Predicting Pathological Response to Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer Using 18FDG-PET/CT

Background

Pathologic complete response (pCR) after neoadjuvant chemoradiation (CRT) has been observed in 15?C30% of patients with locally advanced rectal cancer (LARC). The objective of this study was to determine whether PET/CT can predict pCR and disease-free survival in patients receiving CRT with LARC.

Methods

This is a retrospective review of patients with EUS-staged T3?CT4, N?+?rectal tumors treated with CRT, who underwent pre/post-treatment PET/CT from 2002?C2009. All patients were treated with CRT and surgical resection. Standardized uptake value (SUV) of each tumor was recorded. Logistic regression was used to analyze the association of pre-CRT SUV, post-CRT SUV, %SUV change, and time between CRT and surgery, compared with pCR. Kaplan?CMeier estimation evaluated significant predictors of survival.

Results

Seventy patients (age 62?years; 42M:28F) with preoperative stage T3 (n?=?61) and T4 (n?=?9) underwent pre- and post-CRT PET/CT followed by surgery. The pCR rate was 26%. Median pre-CRT SUV was 10.8, whereas the median post-CRT SUV was 4 (P?=?0.001). Patients with pCR had a lower median post-CRT SUV compared with those without (2.7 vs. 4.5, P?=?0.01). Median SUV decrease was 63% (7.5?C95.5%) and predicted pCR (P?=?0.002). Patients with a pCR had a greater time interval between CRT and surgery (median, 58 vs. 50?days) than those without (P?=?0.02). Patients with post-CRT SUV?P?=?0.03). Patients with SUV decrease ??63% had improved overall survival at median follow-up of 40?months than those without (P?=?0.006).

Conclusions

PET/CT can predict response to CRT in patients with LARC. Posttreatment SUV, %SUV decrease, and greater time from CRT to surgery correlate with pCR. Post-CRT, SUV?相似文献