Prognostic value of 18FDG PET/CT volumetric parameters in the survival prediction of patients with pancreatic cancer

PurposeTo investigate the value of ¹⁸ FDG PET/CT volumetric parameters in the prediction of overall survival (OS) in patients with pancreatic cancer and also, assess their independence relative to well-established clinico-pathological variables.MethodsWe conducted a retrospective analysis of patients with a confirmed diagnosis of pancreatic cancer who underwent ¹⁸ FDG PET/CT. The tumour maximum standardised uptake value (SUV_max) in addition to SUV_mean, metabolic tumour volume (MTV) and total lesion glycolysis (TLG) were calculated. The prognostic value of ¹⁸ FDG PET/CT and clinico-pathological parameters for OS were assessed using univariate and multivariable analyses.ResultsA sum of 89 patients were analysed in this study. Median survival for patients categorised as having high TLG (≥55) and low TLG (<55) was 18 vs 5 months (p < 0.001). Similarly, the respective high vs low SUV_mean, MTV and SUVmax were 18 vs 6 months (p = 0.001), 16 vs 6 months (p = 0.002) and 18 vs 6 months (p = 0.001). Univariate analysis showed SUV_max, SUV_mean, MTV, TLG, tumour size, tumour differentiation and presence of distant metastasis as prognostic factors for OS. On multivariable analysis, TLG (HR 2.0, 95% CI 1.26–3.18, p = 0.004) and the presence of distant metastasis (HR 3.37, 95% CI 1.97–5.77, p < 0.001) emerged as independent prognostic factors. Subgroup analysis identified TLG as the only significant PET metric after adjusting for the presence of distant metastasis.Conclusions¹⁸ FDG PET/CT is a useful tool in the preoperative evaluation of patients with pancreatic cancer. Tumour TLG offer an independent prognostic value in both potentially operable and metastatic disease settings.     

Metabolic tumor burden predicts prognosis of ovarian cancer patients who receive platinum‐based adjuvant chemotherapy

Volumetric parameters of positron emission tomography–computed tomography using 18F‐fludeoxyglucose (¹⁸F‐FDG PET/CT) that comprehensively reflect both metabolic activity and tumor burden are capable of predicting survival in several cancers. The aim of this study was to investigate the predictive performance of metabolic tumor burden measured by ¹⁸F‐FDG PET/CT in ovarian cancer patients who received platinum‐based adjuvant chemotherapy after cytoreductive surgery. Included in this study were 37 epithelial ovarian cancer patients. Metabolic tumor burden in terms of metabolic tumor volume (MTV) and total lesion glycolysis (TLG), clinical stage, histological type, residual tumor after primary cytoreductive surgery, baseline serum carbohydrate antigen 125 (CA125) level, and the maximum standardized uptake value (SUV_max) were determined, and compared for their performance in predicting progression‐free survival (PFS). Metabolic tumor volume correlated with CA125 (r = 0.547, P < 0.001), and TLG correlated with SUV_max and CA125 (SUV_max, r = 0.437, P = 0.007; CA125, r = 0.593, P < 0.001). Kaplan–Meier analysis showed a significant difference in PFS between the groups categorized by TLG (P = 0.043; log–rank test). Univariate analysis indicated that TLG was a statistically significant risk factor for poor PFS. Multivariate analysis adjusted according to the clinicopathological features was carried out for MTV, TLG, SUV_max, tumor size, and CA125. Only TLG showed a significant difference (P = 0.038), and a 3.915‐fold increase in the hazard ratio of PFS. Both MTV and TLG (especially TLG) could serve as potential surrogate biomarkers for recurrence in patients who undergo primary cytoreductive surgery followed by platinum‐based chemotherapy, and could identify patients at high risk of recurrence who need more aggressive treatment.     

应用根治性IMRT结合降低预防照射区剂量治疗Ⅲ期SCLC研究

目的 分析应用根治性IMRT结合降低预防照射区剂量治疗Ⅲ期SCLC的疗效和不良反应。方法 回顾分析2010—2012年间收治的40例Ⅲ期SCLC患者资料。PGTV总剂量60 Gy分30次,PTV总剂量54 Gy分30次。全部接受了铂类联合依托泊苷或替尼泊苷方案的诱导化疗,31例辅助化疗,22例同期放化疗。17例患者接受了脑预防照射(25 Gy分10次)。采用RECIST 1.0和CTCAE 4.0 标准分别评价近期疗效和不良反应。采用Kaplan-Meier法计算生存率。结果 近期有效率98%。随访率100%,随访时间满2年者22例。1、2年OS分别为84%、48%,LRFS分别为89%、85%,PFS分别为61%、41%。治疗相关性肺炎发生率0~1级65%、2级 25%、3级5%、5级5%,治疗相关性食管炎发生率0~1级53%、2级43%、3级5%。结论 初步结果显示根治性IMRT结合降低预防照射区剂量治疗Ⅲ期SCLC是安全有效的,值得进一步大样本前瞻性随机分组研究。     

Prognostic role of baseline 18F‐FDG PET/CT parameters in MALT lymphoma

Mucosa‐associated lymphoid tissue (MALT) lymphoma is an indolent lymphoma with good prognosis and variable fluorine‐18 fluorodeoxyglucose (¹⁸F‐FDG) avidity. Many possible prognostic factors have been investigated with controversial results, but the possible prognostic role of ¹⁸F‐FDG positron emission tomography/computed tomography (PET/CT) remains unclear. Our aim was to evaluate the prognostic impact of qualitative and semiquantitative baseline PET/CT parameters on outcome of MALT lymphoma. We retrospectively enrolled 161 patients with histologically confirmed MALT lymphoma who underwent ¹⁸F‐FDG PET/CT before any treatment. PET images were qualitatively and semiquantitatively analyzed by measuring the maximum standardized uptake value body weight (SUVbw), lean body mass (SUVlbm), body surface area (SUVbsa), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). The Kaplan‐Meier method was used to estimate the progression‐free survival (PFS) and overall survival (OS) times. Cox regression models were performed to determine the relation between PET/CT features and OS and PFS. Ninety‐eight patients had positive ¹⁸F‐FDG PET/CT showing ¹⁸F‐FDG uptake (mean SUVbw, 10.1; SUVlbm, 7.2; SUVbsa, 2.7; MTV, 88.8; and TLG, 526); the remaining 63 were not ¹⁸F‐FDG avid. ¹⁸F‐FDG avidity was significantly correlated with tumor size and Ki‐67 score. Relapse/progression of disease occurred in 47 patients with an average time of 40.2 months; death occurred in 12 patients with an average of 59 months. At a median follow‐up of 62 months, median PFS and OS were 52 and 62 months, respectively. Advanced tumor stage and extragastric site were demonstrated to be independent prognostic factors for PFS, while only tumor stage for OS. Instead, PET/CT parameters were not related to survival, despite positive correlation at univariate analysis between MTV and TLG with PFS and positive PET/CT with PFS and OS. In conclusion, a 61% rate of PET avidity in biopsy‐confirmed MALT lymphoma was found, and it was correlated with tumor size and Ki‐67 score. Only tumor stage and localization were independently correlated with PFS and OS.     

Prognostic models integrating quantitative parameters from baseline and interim positron emission computed tomography in patients with diffuse large B-cell lymphoma: post-hoc analysis from the SAKK38/07 clinical trial

Positron emission computed tomography (PET/CT) in patients with diffuse large B-cell lymphoma (DLBCL) enrolled in a prospective clinical trial were reviewed to test the impact of quantitative parameters from interim PET/CT scans on overall (OS) and progression-free (PFS) survival. We centrally reviewed baseline and interim PET/CT scans of 138 patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone given every 14 days (R-CHOP14) in the SAKK38/07 trial ( ClinicalTrial.gov identifier: NCT00544219). Cutoff values for maximum standardized uptake value (SUV_max), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and metabolic heterogeneity (MH) were defined by receiver operating characteristic analysis. Responses were scored using the Deauville scale (DS). Patients with DS 5 at interim PET/CT (defined by uptake >2 times higher than in normal liver) had worse PFS (P = 0.014) and OS (P < 0.0001). A SUV_max reduction (Δ) greater than 66% was associated with longer PFS (P = 0.0027) and OS (P < 0.0001). Elevated SUV_max, MTV, TLG, and MH at interim PET/CT also identified patients with poorer outcome. At multivariable analysis, ΔSUV_max and baseline MTV appeared independent outcome predictors. A prognostic model integrating ΔSUV_max and baseline MTV discriminated three risk groups with significantly (log-rank test for trend, P < 0.0001) different PFS and OS. Moreover, the integration of MH and clinical prognostic indices could further refine the prediction of OS. PET metrics-derived prognostic models perform better than the international indices alone. Integration of baseline and interim PET metrics identified poor-risk DLBCL patients who might benefit from alternative treatments.     

The prognostic value of volume-based parameters using <Superscript>18</Superscript>F-FDG PET/CT in gastric cancer according to HER2 status

Background

We aimed to find the clinical value of metastatic tumor burden evaluated with F18-FDG PET/CT in gastric cancer patients, considering the human epidermal growth factor receptor 2 (HER2) status.

Methods

We retrospectively reviewed 124 patients with locally advanced or metastatic gastric cancer at Yonsei Cancer Center between January 2006 and December 2014 who had undergone baseline FDG PET/CT before first-line chemotherapy. We measured the maximum standardized uptake value from the primary tumor (SUV_max) and whole-body (WB) PET/CT parameters, including WB SUV_max, WB SUV_mean, WB metabolic tumor volume (WB MTV), and WB total lesion glycolysis (WB TLG), in all metabolically active metastatic lesions (SUV threshold ≥2.5 or 40% isocontour for ≤2.5), and we determined their association with patient survival outcomes.

Results

SUV_max was higher in HER2-positive gastric cancers (median 12.1, range 3.4–34.6) compared to HER-2 negative (7.4, 1.6–39.1, P < 0.001). Among all patients, WB TLG > 600, which is indicative of a high metastatic tumor burden, showed worse progression-free survival (PFS) [hazard ratio (HR), 2.003; 95% CI, 1.300–3.086; P = 0.002] and overall survival (OS) (HR, 3.001; 95% CI, 1.950–4.618; P < 0.001) than did WB TLG ≤ 600. Among HER2-positive gastric cancer patients treated with trastuzumab, higher metabolic tumor burden predicted worse OS, but not PFS.

Conclusions

HER2-positive gastric cancers had higher SUV_max compared to HER2-negative gastric cancers. In both HER2-negative patients and -positive patients receiving trastuzumab, FDG PET/CT volume-based parameters may have a role in further stratifying the prognosis of stage IV gastric cancer.

     

Prognostic value of preoperative intratumoral FDG uptake heterogeneity in early stage uterine cervical cancer

Objective

We investigated the prognostic value of intratumoral [¹⁸F]fluorodeoxyglucose (FDG) uptake heterogeneity (IFH) derived from positron emission tomography/computed tomography (PET/CT) in patients with cervical cancer.

Methods

Patients with uterine cervical cancer of the International Federation of Obstetrics and Gynecology (FIGO) stage IB to IIA were imaged with [¹⁸F]FDG PET/CT before radical surgery. PET/CT parameters such as maximum and average standardized uptake values (SUV_max and SUV_avg), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and IFH were assessed. Regression analyses were used to identify clinicopathological and imaging variables associated with progression-free survival (PFS).

Results

We retrospectively reviewed clinical data of 85 eligible patients. Median PFS was 32 months (range, 6 to 83 months), with recurrence observed in 14 patients (16.5%). IFH at an SUV of 2.0 was correlated with primary tumor size (p<0.001), SUV_tumor (p<0.001), MTV_tumor (p<0.001), TLG_tumor (p<0.001), depth of cervical invasion (p<0.001), and negatively correlated with age (p=0.036). Tumor recurrence was significantly associated with TLG_tumor (p<0.001), MTV_tumor (p=0.001), SUV_LN (p=0.004), IFH (p=0.005), SUV_tumor (p=0.015), and FIGO stage (p=0.015). Multivariate analysis identified that IFH (p=0.028; hazard ratio, 756.997; 95% CI, 2.047 to 279,923.191) was the only independent risk factor for recurrence. The Kaplan-Meier survival graphs showed that PFS significantly differed in groups categorized based on IFH (p=0.013, log-rank test).

Conclusion

Preoperative IFH was significantly associated with cervical cancer recurrence. [¹⁸F]FDG based heterogeneity may be a useful and potential predicator of patient recurrence before treatment.     

疗前FDG标准摄取值预测局部晚期鼻咽癌调强放疗疗效探讨

目的 评价疗前PE-CT FDG最大标准摄取值(SUV_max)预测局部晚期鼻咽癌调强放疗(IMRT)预后的价值。方法 140例疗前行全身或头颈部FDG PET-CT并接受根治性IMRT的Ⅲ~Ⅳ_b期(UICC/AJCC-6^th分期)鼻咽癌病例被纳入研究。分别分析鼻咽原发灶 SUV_max（SUV_max-P)、颈部转移淋巴结 SUV_max(SUV_max-N)与临床各因素和临床疗效的关系。结果 全组 SUV_max-P中位数为10.4,SUV_max-N为6.2。SUV_max-P与T分期(R=0.279,P=0.001)、SUV_max-N与N分期(R=0.334,P=0.000)均相关。局部复发与无复发患者 SUV_max-P中位数为9.2与10.4(U=560.50,P=0.805),SUV_max-N中位数为4.0与5.0(U=576.00,P=0.908)。远处转移与无转移患者 SUV_max-P中位数为11.9与9.8(U=987.50,P=0.014),SUV_max-N中位数为5.0与5.0(U=1266.00,P=0.348)。与 5年无远处转移生存(DMFS)和 5年总生存(OS)相关最佳截断点 SUV_max-P均为10.2。SUV_max-P≤10.2与>10.2患者 5年DMFS和OS分别为95.5%与69.1%(χ²=15.88,P=0.000)和94.0%与68.4%(χ²=15.56,P=0.000)。多因素分析显示 SUV_max-P是 5年DMFS及OS的预后因素(HR=7.87,P=0.001及 HR=5.14,P=0.003)。结论 疗前原发灶FDG SUV_max可能是预测局部晚期鼻咽癌IMRT后远处转移和生存的有效生物学指标。     

High 2-[F]fluoro-2-deoxy-d-glucose (FDG) uptake measured by positron emission tomography is associated with reduced overall survival in patients with oral squamous cell carcinoma

Patients with oral squamous cell carcinoma (OSCC) and poor prognosis may benefit from an intensification of the initial therapy scheme. To improve the clinical management of these patients, there is a strong requirement for an accurate assessment of the malignant properties of the individual lesion. The objective of the present analysis was to define the potential value of 2-[¹⁸F]fluoro-2-deoxy-d-glucose (¹⁸FDG) uptake in the tumor measured by positron emission tomography (PET) in predicting patients’ outcome in the clinical course of OSCC. In this respect, a clinically well-defined cohort of 79 patients with primary OSCC was retrospectively evaluated. ¹⁸FDG uptake in the primary tumor site was quantified by calculation of the maximum standardized uptake values (SUV_max). Subsequent statistical analyses found, that ¹⁸FDG uptake of the primary tumor was significantly higher in stage T3/T4 vs. T1/T2 (p < 0.001), in UICC stage IV vs. stage I–III (p = 0.01), and in N1–3 vs. N0 tumors (p < 0.001), respectively. To define SUV_max cut-off values for survival analyses, receiver operating curves (ROC) were calculated for overall and disease-free survival after 36 and 60 months, respectively. Univariate survival analysis showed that high SUV_max was significantly associated with shortened overall survival after 36 (p = 0.026) and 60 months (p = 0.02). Subsequent multi-variate Cox regression analysis including SUV_max, age, gender and UICC stage as co-variables determined that, high SUV_max was the only predictor of inferior overall survival after 60 months (p = 0.035) in this model. In conclusion, ¹⁸FDG uptake detected by PET predicts adverse outcome of patients with OSCC in this retrospective analysis. ¹⁸FDG–PET might be a promising tool to contribute to therapeutic decisions and should be evaluated in future prospective studies.     

Prognostic significance of 18F-FDG PET/CT in patients with colorectal cancer liver metastases after hepatectomy

Introduction

Colorectal cancer liver metastasis (CRLM) can be cured with surgery. To improve survival, optimal selection of CRLM patients should be done cautiously, which may be facilitated by preoperative [F-18] fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT).

Prognostic value of post-treatment 18F-FDG PET/CT for advanced head and neck cancer after combined intra-arterial chemotherapy and radiotherapy简

Objective：To clarify the prognostic value of post-treatment 18F-fluorodeoxyglucose （FDG） positron emission tomography （PET）/computed tomography （CT） in patients with advanced head and neck squamous cell carcinoma （HNSCC） after combined intra-arterial chemotherapy and radiotherapy （IACR）.Methods：Thirty-six patients with HNSCC who underwent IACR were recruited.The period from the end of IACR to the last post-treatment 18F-FDG PET/CT examination was 8-12 weeks.Both patient-based and lesion-based analyses were used to evaluate the PET/CT images.For lesion-based analysis,36 regions （12 lesions of recurrences and 24 scars at primary sites） were selected.The Kaplan-Meier method was used to assess the overall survival （OS） stratified by 18F-FDG uptake or visual interpretation results.Results：Twelve patients with recurrence were identified by six months after IACR.The sensitivity and specificity in the patient-based analysis were 67％ （8/12） and 88％ （21/24）,respectively.The mean OS was estimated to be 12.1 months （95％ CI,6.3-18.0 months） for the higher maximum standardized uptake value （SUVmax） group （n=7） and 44.6 months （95％ CI,39.9-49.3 months） for the lower SUVmax group （n=29）.OS in the higher SUVmax group （cut-off point,6.1） or positive visual interpretation group was significantly shorter than that in the lower SUVmax or negative visual interpretation group （P＜0.001 and P＜0.05,respectively）.Conclusions：The SUVmax and visual interpretation of HNSCC on post-IACR 18F-FDG PET/CT can provide prognostic survival estimates.     

New positron emission tomography derived parameters as predictive factors for recurrence in resected stage I non-small cell lung cancer

Background

The recurrence rate for stage I non-small cell lung cancer is high, with 20–40% of patients that relapse after surgery. The aim of this study was to evaluate new F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) derived parameters, such as standardized uptake value index (SUV_index), metabolic tumor volume (MTV) and total lesion glycolysis (TLG), as predictive factors for recurrence in resected stage I non-small cell lung cancer.

Methods

We retrospectively reviewed 99 resected stage I non-small cell lung cancer patients that were grouped by SUV_index, TLG and MTV above or below their median value. Disease free survival was evaluated as primary end point.

Results

The 5-year overall survival and the 5-year disease free survival rates were 62% and 73%, respectively. The median SUV_index, MTL and TLG were 2.73, 2.95 and 9.61, respectively. Patients with low SUV_index, MTV and TLG were more likely to have smaller tumors (p ≤ 0.001). Univariate analysis demonstrated that SUV_index (p = 0.027), MTV (p = 0.014) and TLG (p = 0.006) were significantly related to recurrence showing a better predictive performance than SUV_max (p = 0.031). The 5-year disease free survival rates in patients with low and high SUV_index, MTV and TLG were 84% and 59%, 86% and 62% and 88% and 60%, respectively. The multivariate analysis showed that only TLG was an independent prognostic factor (p = 0.014) with a hazard ratio of 4.782.

Conclusion

Of the three PET-derived parameters evaluated, TLG seems to be the most accurate in stratifying surgically treated stage I non-small cell lung cancer patients according to their risk of recurrence.     

[F-18] FDG-PET/CT parameters as predictors of outcome in inoperable NSCLC patients

Background

We evaluated the prognostic significance of standardized uptake value (SUVmax), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) in [F-18] FDG PET/CT findings in patients with inoperable non-small-cell lung cancer (NSCLC).

Patients and methods.

One hundred and three patients (mean age, 65.6 ± 16 years) underwent [F-18] FDG PET/CT before the chemotherapy. The SUVmax value, the MTV (cm³; 42% threshold) and the TLG (g) were registered. The patients were followed up to 18 months thereafter (range 12–55 months). Failure to respond without progression, progression and/or disease-related death constituted surrogate end-points. The optimal SUVmax, MTV and TLG cut-off to predict the patients’ outcome were estimated. PET/CT results were then related to disease outcome (progression free survival; PFS).

Results

The Kaplan-Meier survival analysis for SUVmax showed a significant shorter PFS in patients presenting with lower values as compared to those with higher (p < 0.05, log-rank test). MTV and TLG were not suitable for predicting PFS apart from the subset of patients with mediastinal nodal involvement.

Conclusions

Despite the availability of new tools for the quantitative assessment of disease activity on PET/CT, the SUVmax rather than MTV and TLG remains the only predictor for PFS in NSCLC patients. MTV holds a value only when concomitant nodal involvement occurs.     

Clinicopathologic Significance of False-Positive Lymph Node Status on FDG-PET in Lung Cancer

Introduction2-[¹⁸F] Fluoro-d-deoxyglucose (FDG) positron emission tomography (PET) is a relevant diagnostic procedure for staging lung cancer. However, accurate evaluation of lymph node metastases by PET is controversial because of false-positive FDG uptake.Patients and MethodsA total of 245 patients with lung cancer were retrospectively analyzed. Standardized maximum uptake values (SUV_max) of the primary tumor and lymph nodes were compared to pathologic lymph node metastases to correlate PET findings with clinicopathologic variables and patient outcomes.ResultsThe SUV_max values of metastatic lymph nodes were significantly higher than those of lymph nodes without metastases (P = .0036). When SUV_max ≥ 4 was defined as PET positive for metastasis, the sensitivity, specificity, and accuracy were 48.1%, 79.8%, and 73.1%, respectively. Multivariate logistic regression analysis showed that age > 75 years, bilateral hilar FDG uptake, and no lymph node swelling were significant factors related to false-positive lymph node metastases. Smoking status, FDG uptake in the primary tumor, and concurrent lung diseases were not significant factors.ConclusionMetastatic lymph nodes show higher FDG uptake than false-positive lymph nodes, and older patient age, bilateral hilar FDG uptake, and no swollen nodes are associated with no metastases. Patients with lymph node metastases have worse survival than those with false-positive FDG-PET findings. However, abnormal FDG uptake in the lymph node is an important prognostic factor.     

Evaluation of children with craniopharyngioma using carbon-11 methionine PET prior to proton therapy

Background

Fluorine-18 (¹⁸F) fluorodeoxyglucose (FDG) positron emission tomography (PET) is limited in its evaluation of brain tumors due to the high basal activity of the cerebral cortex and white matter. Carbon-11 methionine (¹¹C MET) has little uptake under normal conditions. We prospectively investigated the uptake of ¹⁸F FDG and ¹¹C MET PET in patients with craniopharyngioma prior to proton therapy.

Methods

Ten patients newly diagnosed with craniopharyngioma underwent PET imaging using ¹⁸F FDG and ¹¹C MET. PET and MRI studies were registered to help identify tumor volume. Measurements of maximum standardized uptake value (SUV_max) were taken of the tumor and compared with noninvolved left frontal background white matter using a paired t-test. Uptake was graded using a 4-point scale.

Results

Median patient age was 9 years (range 5–19). Seven patients were diagnosed by pathology, 1 by cyst fluid aspiration, and 2 by neuroimaging. Median FDG SUV_max for tumor and background were 2.65 and 3.2, respectively. Median MET SUV_max for tumor and background were 2.2 and 1, respectively. There was a significant difference between MET tumor SUV_max and MET background SUV_max (P = .0001). The difference between FDG tumor SUV_max and FDG background SUV_max was not significant (P = .3672).

Conclusion

¹¹C MET PET uptake is significantly greater within the tumor compared with noninvolved background white matter, making it more useful than FDG PET in identifying active tumor in patients with craniopharyngioma. Future work will focus on using ¹¹C MET PET to discriminate between active and inactive tumor after irradiation.     

Comparative study of the value of dual tracer PET/CT in evaluating breast cancer

The present study was conducted to assess the relationship between tumor uptake and pathologic findings using dual‐tracer PET/computed tomography (CT) in patients with breast cancer. Seventy‐four patients with breast cancer (mean age 54 years) who underwent ¹¹C‐choline and 2‐[¹⁸F]fluoro‐2‐deoxy‐d ‐glucose (¹⁸F‐FDG) PET/CT prior to surgery on the same day were enrolled in the present study. Images were reviewed by a board‐certified radiologist and two nuclear medicine specialists who were unaware of any clinical information and a consensus was reached. Uptake patterns and measurements of dual tracers were compared with the pathologic findings of resected specimens as the reference standard. Mean (±SD) tumor size was 5.9 ± 3.2 cm. All primary tumors were identified on ¹⁸F‐FDG PET/CT and ¹¹C‐choline PET/CT. However, ¹⁸F‐FDG PET/CT demonstrated focal uptake of the primary tumor with (n = 38; 51%) or without (n = 36; 49%) diffuse background breast uptake. Of the pathologic findings, multiple logistic regression analysis revealed an independent association between fibrocystic change and diffuse background breast uptake (odds ratio [OR] 8.57; 95% confidence interval [CI] 2.86–25.66; P < 0.0001). Tumors with higher histologic grade, nuclear grade, structural grade, nuclear atypia, and mitosis had significantly higher maximum standardized uptake values (SUV_max) and tumor‐to‐background ratios (TBR) for both tracers. Multiple logistic regression analysis revealed that only the degree of mitosis was independently associated with a high SUV_max (OR 7.45; 95%CI 2.21–25.11; P = 0.001) and a high TBR (OR 5.41; 95%CI 1.13–25.96; P = 0.035) of ¹¹C‐choline PET/CT. In conclusion, ¹¹C‐choline may improve tumor delineation and reflect tumor aggressiveness on PET/CT in patients with breast cancer.     

2-[18F]-FDG PET/CT Role in Detecting Richter Transformation of Chronic Lymphocytic Leukemia and Predicting Overall Survival

IntroductionChronic lymphocytic leukemia (CLL) is an indolent, low-grade B-cell lymphoproliferative disorder, which may evolve into aggressive lymphoma, a phenomenon called Richter syndrome (RS). Our aim was to study the accuracy of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (2-[18F]-FDG PET/CT) and its semiquantitative parameters for the detection of RS and the impact on overall survival (OS).Materials and MethodsEighty patients with histologically proven CLL were retrospectively included. PET/CT images were qualitatively and semiquantitatively examined by estimating the maximum standardized uptake value body weight (SUVbw), lean body mass (SUVlbm), body surface area (SUVbsa), lesion-to-blood-pool SUV ratio (L-BP SUV R), lesion-to-liver SUV ratio (L-L SUV R), total lesion glycolysis (TLG), and metabolic tumor volume (MTV) and comparing them with the main clinical-histologic variables. OS curves were plotted according to the Kaplan-Meier method.ResultsSeventy-eight patients had positive 2-[¹⁸F]-FDG PET/CT, whereas the remaining 2 were not FDG-avid. All PET/CT metabolic parameters were significantly higher in the RS group compared with the no-RS group, except for MTV and TLG. The best thresholds identified were 9 for SUVbw, 5.3 for SUVlbm, 1.7 for SUVbsa, 2 for L-L SUV R, and 4.8 for L-BP SUV R. After a median follow-up of 32 months, 24 patients died; OS was significantly shorter in patients with RS than patients without RS (16.5 vs. 27.8 months; P = .001). Binet-stage, B symptoms, SUVbw, SUVlbm, SUVbsa, L-L SUV R, and L-BP SUV R were shown to be independent prognostic features.ConclusionsSemiquantitative PET/CT parameters that are SUV-related may be useful in discriminating patients with a high risk of developing RS and also for predicting OS.     

Correlation of [18F]‐2‐fluoro‐deoxy‐D‐glucose positron emission tomography standard uptake values with the cellular composition of stage I nonsmall cell lung cancer

BACKGROUND:

The aim of the current study was to determine whether the [18F]‐2‐fluoro‐deoxy‐D‐glucose (FDG) positron emission tomography (PET) standardized uptake value (SUV) in patients with a new diagnosis of stage I lung cancer correlates with a specific cellular component in the primary tumor.

METHODS:

This study was Health Insurance Portability and Accountability Act compliant and approved by our Institutional Review Board with a waiver of informed consent. Forty patients with stage I nonsmall cell lung cancer (NSCLC) who underwent FDG‐PET imaging at the time of diagnosis followed by surgical resection were retrospectively identified. Histologic sections of the primary tumor were reviewed by a pathologist without any clinical data and scored according to the percentage of each cellular component (tumor cells, normal stroma, inflammatory cells, necrosis, fibrosis, and other). Each component was compared with maximal (SUV_max) and mean (SUV_mean) SUVs using Pearson correlation coefficient analysis.

RESULTS:

The mean SUV_max and SUV_mean values for 40 stage I NSCLC tumors were 8.8 and 5.4, respectively. The mean histologic composition of tumor specimens in order of frequency was as follows: tumor cells (38.9%), fibrosis (30.8%), inflammatory cells (14.8%), normal stroma (5.2%), necrosis (5.8%), and other components (4.5%); however, there was considerable variation noted among individual tumors. There was no statistically significant correlation between SUV_max (r = .19; P = .24) or SUV_mean (r = .017; P = .29) and the proportion of tumor cells in the tumor mass or any other cellular components.

CONCLUSIONS:

The cellular composition of stage I NSCLC appears to be highly variable, with no correlation noted between a specific tumor cellular component and FDG activity. Cancer 2010. © 2010 American Cancer Society.     

Prognostic value of 18F-FDG PET/CT before and after radiotherapy for locally advanced nasopharyngeal carcinoma

Background: The purpose of this study was to evaluate the prognostic value of maximal standard uptake values (SUVs_max) from serial fluor-18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in patients with locally advanced nasopharyngeal carcinoma (NPC).Materials and methods: From October 2002 to January 2004, 62 patients with locally advanced NPC who underwent ¹⁸F-FDG PET/CT scan before and after radiotherapy were reviewed retrospectively. We examined the association of SUV_max and the results of long-term follow-up of the patients.Results: Patients having tumors with a lower SUV_max had significantly better 5-year overall survival (OS) (P= 0.0187) and disease-free survival (DFS) (P = 0.0163) than patients with a greater SUV_max. The patients who showed with metabolic complete response had a significantly higher 5-year OS (P = 0.0237) and DFS (P = 0.0186) than patients with metabolic partial response. Poor prognosis was found in patients with the SUV_max of neck nodes larger than that at the primary tumor site (SUV_max-N > SUV_max-P) (P = 0.0440).Conclusions:¹⁸F-FDG uptake, as measured by the SUV_max before radiotherapy and metabolic response after radiotherapy, may predict the prognosis in locally advanced NPC. High ¹⁸F-FDG uptake before and after radiotherapy may be useful for identifying patients requiring more aggressive treatment.     

Adaptive 18fluoro-2-deoxyglucose positron emission tomography/computed tomography-based target volume delineation in radiotherapy planning of head and neck cancer

Aims

This study investigated an adaptive threshold-based method to delineate the target volume using ¹⁸fluoro-2-deoxyglucose (¹⁸FDG) positron emission tomography/computed tomography (PET/CT) before and during a course of radical radiotherapy or chemoradiotherapy in locally advanced squamous cell carcinoma of the head and neck.

Materials and methods

Ten patients were enrolled between March 2006 and May 2008. ¹⁸FDG PET/CT scans were carried out 72 h before the start of radiotherapy and then at three time points during radiotherapy (8-18, 36-50 and 66 Gy). Functional volumes were delineated using an adaptive iterative algorithm weighted according to the mean standard uptake value (SUV_mean) within the region of interest. The background ¹⁸FDG uptake, maximum standard uptake value (SUV_max) and SUV_mean within the volumes were assessed.

Results

There was no significant reduction in the primary target volumes defined by the adaptive threshold during radiotherapy. However, the SUV_max significantly reduced within the primary (P = 0.003-0.011) and lymph node (P < 0.0001) target volume at 36-50 and 36-66 Gy compared with 0 Gy. The SUV_mean was negatively correlated to radiation dose (P < 0.0001-0.014). The ratio between the background uptake of ¹⁸FDG and the SUV_mean significantly reduced for both the lymph node target volume at 36-50 Gy and the primary volume at 66 Gy. The lack of significant correlation between the defined volume and radiation dose was because the SUV_mean within the region of interest used to define the edge of the volume was equal to or less than the background ¹⁸FDG uptake and the software was unable to effectively differentiate between tumour and background uptake.

Conclusions

The adaptive threshold method may be of benefit when used to define the target volume before the start of radiotherapy. This method was not beneficial during radiotherapy because the software is not sensitive enough to distinguish tumour from background and define a volume. ¹⁸FDG PET/CT-guided volumes delineated by automatic adaptive thresholding methods should only be used for dose escalation with the pretreatment imaging.