Preoperative CA19­9 level and dual time point FDG­PET/CT as strong biological indicators of borderline resectability in pancreatic cancer: A retrospective study.

Tumor resectability, which is increasingly determined based on preoperative chemotherapy, is critical in determining the best treatment for pancreatic cancers. The present study evaluated the usefulness of serum carbohydrate antigen 19-9 (CA19-9) and the preoperative 8F-fluorodeoxyglucose positron emission tomography/computed tomography standardized uptake value (SUV) percentage change (SUVmax%=[(SUVmax2-SUVmax1)/SUVmax1] ×100, where SUVmax1 and SUVmax2 represent the initial and delayed phases, respectively) as biological factors indicative of tumor resectability. The present study included patients with resectable pancreatic cancer who underwent complete surgical resection, for whom both CA19-9 and SUVmax% were documented using cut-off values of 500 U/ml and 24.25%, respectively. Patients were classified as follows: i) High CA19-9 and SUVmax%: both CA19-9 and SUVmax% were elevated; ii) high CA19-9 or SUVmax%: either CA19-9 or SUVmax% were elevated; or iii) low CA19-9 and SUVmax%: neither value met the cut-off. Relapse-free survival (RFS) and overall survival (OS) were calculated, for which univariate and multivariate analyses were performed. Of the 86 patients included, 39 were classified as high CA19-9 or SUVmax% and 12 as high CA19-9 and SUVmax%, with the former group having a significantly worse RFS (vs. low CA19-9 and SUVmax%; P<0.001; vs. high CA19-9 or SUVmax%; P=0.011) and OS (vs. low CA19-9 and SUVmax%, P=0.002; vs. high CA19-9 or SUVmax%, P<0.001). Therefore, high CA19-9 and SUVmax% was an independent predictor of worse RFS (P<0.001) and OS (P=0.003). In conclusion, CA19-9 and SUVmax% can be utilized as biological indicators of resectability.

Impact of retention index on the neoadjuvant chemotherapy effect and the prognosis in oesophageal cancer.

OBJECTIVE: The relationship between retention index calculated from dual-time point 18F-fluorodeoxyglucose positron emission tomography-computed tomography and oesophageal cancer prognosis remains unknown. This study aimed to determine usefulness of retention index as a predictor of long-term prognosis of oesophageal cancer and neoadjuvant chemotherapy efficacy. METHODS: A total of 151 patients with oesophageal cancer who underwent esophagectomy were evaluated retrospectively in this study. We acquired positron emission tomography scans 60 and 120 min (SUVmax1 and SUVmax2, respectively) after the intravenous administration of 3.7 Mbq/kg 18F-fluorodeoxyglucose. The patients were divided into two groups: high-retention index (retention index ≥29%, 107 patients) and low-retention index (retention index <29%, 44 patients). Retention index was calculated as follows: retention index (%) = [(SUVmax2 - SUVmax1)/SUVmax1] × 100. RESULTS: The overall survival and relapse-free survival rates in the high-retention index group were significantly lower than those in the low-retention index group (P < 0.001). Our multivariate analysis identified that the high-retention index group contained independent risk factors for overall survival (hazard ratio: 2.44, P = 0.009) and relapse-free survival (hazard ratio: 2.61, P = 0.002). The high-retention index group exhibited a lower partial response rate to neoadjuvant chemotherapy evaluated by computed tomography (P < 0.001) and a lower pathological therapeutic effect in the resected specimen (P = 0.019) than the low-retention index group. CONCLUSIONS: The retention index was associated with neoadjuvant chemotherapy responses and long-term prognosis for oesophageal cancer.

Clinical Impact of Dual Time Point 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Fusion Imaging in Pancreatic Cancer.

We examined the value of preoperative dual time point (DTP) 18F-fluorodeoxyglucose positron emission tomography/computed tomography fusion imaging (FDG PET/CT) as a predictor of early recurrence or the outcomes in patients with pancreatic cancer. Standardized uptake values (SUVs) in DTP FDG PET/CT were performed as preoperative staging. SUVmax1 and SUVmax2 were obtained in 60 min and 120 min, respectively. ΔSUVmax% was defined as (SUVmax2 − SUVmax1)/SUVmax1 × 100. The optimal cut-off values for SUVmax parameters were selected based on tumor relapse within 1 year of surgery. Optimal cut-off values for SUVmax1 and ΔSUVmax% were 7.18 and 24.25, respectively. The combination of SUVmax1 and ΔSUVmax% showed higher specificity and sensitivity, and higher positive and negative predictive values for tumor relapse within 1 year than SUVmax1 alone. Relapse-free survival (RFS) was significantly worse in the subgroups of high SUVmax1 and high ΔSUVmax% (median 7.0 months) than in the other subgroups (p < 0.0001). The multivariate Cox analysis of RFS identified high SUVmax1 and high ΔSUVmax% as independent prognostic factors (p = 0.0060). DTP FDG PET/CT may effectively predict relapse in patients with pancreatic cancer. The combination of SUVmax1 and ΔSUVmax% identified early recurrent patient groups more precisely than SUVmax1 alone.

Utility of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Fusion Imaging for Prediction of Metastasis to Sentinel and Nonsentinel Nodes in Patients with Clinically Node-Negative Breast Cancer.

PURPOSE: 18F-Fluorodeoxyglucose positron emission tomography/computed tomography fusion imaging (18F-FDG PET/CT) is an important diagnostic tool in breast cancer. The utility of maximum standardized uptake values (SUVmax) of primary tumors has been evaluated to predict sentinel node (SN) and non-SN metastasis in clinically node-negative (cN0) patients. PATIENTS AND METHODS: 18F-FDG PET/CT was performed on 414 cN0 patients. The following parameters were evaluated: SUVmax at 60 min (SUVmax1), SUVmax at 120 min (SUVmax2), percent change between SUVmax1 and SUVmax2 (ΔSUVmax%), SN metastasis foci maximum size (SN meta size), and ratio of metastatic SNs to total SNs or SN ratio (SNR). It was assessed whether these were risk factors for SN metastasis. The relationship between these parameters and the status of SN and/or non-SN metastasis was retrospectively explored to predict non-SN metastasis. RESULTS: All SUV parameters significantly correlated with pathological T factor (pT), nuclear grade, lymphatic invasion (Ly), and Ki-67 labeling index. On multivariate analysis, pT and Ly were independent predictive factors for SN metastasis. In SN meta-positive cases, SN meta size, SNR, and ΔSUVmax% were predictors for non-SN metastasis on univariate analyses, and the former two were independent predictors on multivariate analysis. The combination of SUVmax2 and ΔSUVmax% was an independent predictor of non-SN metastasis (P = 0.0312) and was associated with prediction of non-SN metastasis negative status with high probability (92.3%). CONCLUSIONS: In patients with cN0 breast cancer, SUV parameters of the primary tumor were correlated with pathological features. The combination of SUVmax2 and ΔSUVmax% may be useful for predicting non-SN metastasis.

Dual time point 18F-fluorodeoxyglucose positron emission tomography/computed tomography fusion imaging (18F-FDG PET/CT) in primary breast cancer.

BACKGROUND: To evaluate the clinicopathological and prognostic significance of the percentage change between maximum standardized uptake value (SUVmax) at 60 min (SUVmax1) and SUVmax at 120 min (SUVmax2) (ΔSUVmax%) using dual time point 18F-fluorodeoxyglucose emission tomography/computed tomography (18F-FDG PET/CT) in breast cancer. METHODS: Four hundred and sixty-four patients with primary breast cancer underwent 18F-FDG PET/CT for preoperative staging. ΔSUVmax% was defined as (SUVmax2 - SUVmax1) / SUVmax1 × 100. We explored the optimal cutoff value of SUVmax parameters (SUVmax1 and ΔSUVmax%) referring to the event of relapse by using receiver operator characteristic curves. The clinicopathological and prognostic significances of the SUVmax1 and ΔSUVmax% were analyzed by Cox's univariate and multivariate analyses. RESULTS: The optimal cutoff values of SUVmax1 and ΔSUVmax% were 3.4 and 12.5, respectively. Relapse-free survival (RFS) curves were significantly different between high and low SUVmax1 groups (P = 0.0003) and also between high and low ΔSUVmax% groups (P = 0.0151). In Cox multivariate analysis for RFS, SUVmax1 was an independent prognostic factor (P = 0.0267) but ΔSUVmax% was not (P = 0.152). There was a weak correlation between SUVmax1 and ΔSUVmax% (P < 0.0001, R2 = 0.166). On combining SUVmax1 and ΔSUVmax%, the subgroups of high SUVmax1 and high ΔSUVmax% showed significantly worse prognosis than the other groups in terms of RFS (P = 0.0002). CONCLUSION: Dual time point 18F-FDG PET/CT evaluation can be a useful method for predicting relapse in patients with breast cancer. The combination of SUVmax1 and ΔSUVmax% was able to identify subgroups with worse prognosis more accurately than SUVmax1 alone.

A new in vivo model to analyze hepatic metastasis of the human colon cancer cell line HCT116 in NOD/Shi-scid/IL-2Rγ(null) (NOG) mice by (18)F-FDG PET/CT.

Clinically, (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG-PET/CT) is useful in the evaluation of various types of human cancers. While PET analysis has been established to evaluate subcutaneous lesions of human cancers in mice, its applications for internal lesions are still being developed. We are currently evaluating new PET approaches for the effective evaluation of in vivo metastatic lesions in the internal organs of small experimental animals. In this study, we analyzed in vivo hepatic metastases of human colonic cancer in immunodeficient mice (NOD/Shi-scid/IL-2Rγ(null), NOG) using PET imaging. This new PET approach has been proposed for the evaluation of in vivo metastatic lesions in internal organs. The human colon cancer line HCT116 (1.0x10(5) and 1.0x10(6) cells/mouse) was transplanted by intrasplenic injection. (18)F-FDG-PET/CT scans were performed 2 weeks after transplantation. After PET/CT scans, histopathological examinations were performed. PET/CT analysis disclosed multiple metastatic foci and increased standardized uptake values (SUV) of FDG in the livers of NOG mice (control, SUVmean 0.450±0.033, SUVmax 0.635±0.017; 1.0x10(5) cells, 0.853±0.087, 1.254±0.237; 1.0x10(6) cells, 1.211±0.108, 1.701±0.158). There were significant differences in FDG uptakes between the three groups (ANOVA, P=0.017 in SUVmean; P=0.044 in SUVmax, n=2). We clearly and quantitatively detected images of hepatic metastasis in the livers of NOG mice by (18)F-FDG-PET/CT in vivo. PET/CT analysis of internal organ lesions of human cancerous xenografts is a new reliable experimental system to simulate metastases. This model system is useful for analyzing metastatic mechanisms and for developing new novel drugs targeting hepatic metastases of cancer.

A case of early stage lung cancer detected by repeated cancer screening with positron emission tomography.

There has been an increase in the detection rate of small early lung cancer due to recent improvements in imaging technology. However, conventional imaging modalities such as computed tomography (CT) alone are not capable of differentiating small pulmonary nodules. New modalities such as F-18 2'-deoxy-2fluoro-D-glucose (FDG) positron emission tomography combined with CT (PET/CT) have contributed to the evaluation of lung cancer staging, although the differential diagnosis of pulmonary nodules showing ground-glass opacity (GGO) with PET/CT is controversial. In Japan, cancer screening with whole body FDG-PET has been available for asymptomatic individuals, and it has been reported that a wide variety of cancer types are detectable by FDG-PET at potentially curable stages. We present the case of a 62-year-old male with early lung cancer, which was revealed by repeated health screening. A PET/CT scan revealed definite intense FDG uptake (SUVmax 1.2) in the pulmonary nodules of the right upper lobe, while no definite FDG uptake was observed in the lesion in the previous annual screening. Right upper lobectomy was performed, and the pathological diagnosis was well-differentiated adenocarcinoma. Five-year survival has been noted since the thoracotomy, and the patient is doing well without recurrence. This is a significant case of early lung cancer with GGO lesions, which revealed intense FDG uptake during an annual repeated health screening with FDG-PET/CT.

18F-fluorodeoxyglucose positron emission tomography optimizes neoadjuvant chemotherapy for primary breast cancer to achieve pathological complete response.

BACKGROUND: To assess the usefulness of positron emission tomography combined with computed tomography using (18)F-fluorodeoxyglucose (FDG PET/CT) for optimizing chemotherapy during neoadjuvant chemotherapy for primary breast cancer. METHODS: One hundred and eight patients (110 tumors) with breast cancer (≥2 cm, stages II and III) received neoadjuvant chemotherapy consisting of an anthracycline-based regimen and taxane. The maximal value of the baseline standardized uptake value (SUV) and the change in SUV after four cycles of an anthracycline-based regimen relative to baseline SUV were assessed for predicting pathological complete response (pCR) after sequential taxane. RESULTS: Tumors with pCR had significantly higher baseline SUV (9.3 ± 3.7 SD) compared to those with non-pCR (7.2 ± 3.8 SD) (p = 0.02), but there was a considerable overlap between two groups. On PET scan after four cycles of chemotherapy, thirty-three patients (33.7%) with a 72.1% or greater reduction in SUV were considered as responders and the performance in predicting pCR had a sensitivity of 88.9% and specificity of 78.7%. CONCLUSION: The baseline SUV could not be a useful indicator for predicting pCR due to the wide range in sensitivity. On the other hand, a relative change in SUV after completion of an anthracycline-based regimen could be useful for predicting pCR.

Clinical implications of 18F-fluorodeoxyglucose positron emission tomography/computed tomography at delayed phase for diagnosis and prognosis of malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) has a poor prognosis, and conventional imaging modalities do not reflect the prognosis of MPM. In this study, the clinical significance of 18F-fluorodeoxyglucose positron emission tomography/computed tomography fusion imaging (18F-FDG PET/CT) was evaluated for the differential diagnosis, staging and prognosis in MPM patients. Ninety patients who underwent 18F-FDG PET/CT scanning due to a clinical diagnosis or suspicion of MPM prior to therapy were reviewed. Of 90 patients, 31 were pathologically diagnosed as MPM. Maximum standardized uptake values (SUVmax) were semi-quantitatively obtained from PET/CT 60 min (early phase) and 120 min (delayed phase) after injection of 18F-FDG, and the clinicopathological correlations with the level of SUVmax obtained from PET/CT were examined. The survival curves of MPM patients were plotted according to the methods of Kaplan-Meier. The prognostic implications of the level of SUVmax were estimated by t-test. PET/CT scan showed intense abnormal FDG uptake (SUVmax>2.0) in the pleural lesions of all 31 MPM patients at delayed phase, while it showed abnormal FDG uptake in 30 (97%) patients at early phase. In all 31 MPM patients, the values of SUVmax at delayed phase were higher than those at the early phase. PET/CT also indicated metastasis in the lymph node in 7 patients (23%) and in the systemic lesions in 8 patients (26%) with MPM. Twenty-three MPM patients with high SUVmax, whose prognosis was apparent, showed significantly poorer prognosis in both early and delayed phase (respectively, p=0.03 and p=0.01, t-test). The results showed that 18F-FDG PET/CT at delayed phase is very useful for the diagnosis of pleural diseases, and SUVmax on PET/CT in the delayed phase is a more reliable prognostic factor than that in the early phase. High uptake of 18F-FDG PET/CT may be a predictive factor of prognosis in MPM patients.

A case of primary lung cancer lesion demonstrated by F-18 FDG positron emission tomography/computed tomography (PET/CT) one year after the detection of metastatic brain tumor.

Cancer of unknown primary origin (CUP) is an aggressive disease with a poor prognosis. Metastatic brain tumors occur in approximately 15% of all cancer patients. F-18 2'-deoxy-2fluoro-D-glucose (FDG) positron emission tomography (PET) combined with computed tomography (PET/CT) contributes to the evaluation of cancer staging, although the benefits of PET/CT for detection of CUP origins has yet to be determined. In this study, we present a 37-year-old man with a brain tumor detected by magnetic resonance imaging. Surgical biopsy indicated a metastatic undifferentiated carcinoma, while clinical examination and a CT scan did not detect any abnormalities, with the exception of brain metastases. PET/CT did not reveal abnormal FDG uptake. PET/CT revealed abnormal intense FDG uptake in a small nodular lesion in the right lung 1 year following the detection of brain metastasis, and no other abnormal FDG uptake was observed elsewhere in the body. Right upper lobectomy and dissection of mediastinal lymph nodes were performed. The pathological diagnosis was poorly differentiated adenocarcinoma, which was similar to the brain metastatic lesion, and there was no lymph node metastasis. This case revealed an extremely rare lung cancer with primary lesions demonstrated by PET/CT 1 year after the detection of brain metastasis. This case reveals that F-18 FDG PET/CT imaging of CUP origin is capable of positively impacting on the identification of small primary tumor foci.

Early metabolic response to neoadjuvant letrozole, measured by FDG PET/CT, is correlated with a decrease in the Ki67 labeling index in patients with hormone receptor-positive primary breast cancer: a pilot study.

PURPOSE: To assess whether the early metabolic response evaluated by (18)F-fluorodeoxy-glucose positron emission combined with computed tomography (FDG PET/CT) predicts the morphological, pathological, and cell-cycle responses to neoadjuvant endocrine therapy of hormone receptor-positive primary breast cancer. STUDY DESIGN: Eleven patients (12 tumors) with estrogen receptor-positive (Allred score 7 or 8) primary breast cancer were enrolled. All patients received a daily dose (2.5 mg) of letrozole for 12 weeks followed by surgery. Sequential FDG PET/CT scans were performed before treatment (baseline), at 4 weeks after the initiation of endocrine therapy (PET2), and prior to surgery (PET3). Tumors showing a 40% or more reduction and those showing a less than 40% reduction in the standardized uptake value maximum (SUV(max)) at PET2 compared with the baseline PET were defined as metabolic responders and metabolic nonresponders, respectively. Change in tumor size as measured by ultrasound (morphological response), pathological response, and change in the Ki67 labeling index in tumor tissue (cell-cycle response) during the neoadjuvant letrozole therapy were compared between the metabolic responders and nonresponders. RESULTS: The average decreases in SUV(max) at PET2 compared with the baseline PET in the metabolic responders (n = 6) and the metabolic nonresponders (n = 6) were 60.9% (±21.3 SD) and 14.2% (±12.0 SD), respectively. At PET3 compared with the baseline PET, the metabolic responders showed a significantly higher decrease of 64.5% (±18.7 SD) (p = 0.0004), whereas the nonresponders showed a nonsignificant decrease of 16.7% (±14.1 SD) (p = 0.06). The morphological and pathological responses after letrozole therapy did not differ between the metabolic responders and nonresponders. The metabolic responders showed a marked decrease in the Ki67 labeling index at 2 weeks after the initiation of treatment (62.9%, ±35.9 SD, p = 0.04) and at surgery (91.7%, ±10.7 SD, p = 0.03) compared with the baseline values. In contrast, metabolic nonresponders showed no significant change in the Ki67 index either after 2 weeks of therapy or at surgery. CONCLUSION: Cell-cycle response monitored by the Ki67 labeling index correlates with metabolic response monitored by tumor SUV(max). Monitoring of tumor SUV(max) using FDG PET/CT may be feasible to predict cell-cycle response to neoadjuvant endocrine therapy of primary breast cancer.

Unique intense uptake demonstrated by (18)F-FDG positron emission tomography/computed tomography in primary pancreatic lymphoma: A case report.

Patients with primary pancreatic lymphoma (PPL), which is rare, require a different therapeutic approach and have a better prognosis than those with pancreatic cancer. However, conventional imaging modalities alone are not able to differentiate between pancreatic cancer and other rare tumors such as PPL, although the accurate diagnosis of PPL is crucial. The development of new modalities such as F-18 2'-deoxy-2fluoro-D-glucose (FDG) positron emission tomography combined with computed tomography (PET/CT) contributes to the evaluation of lymphoma staging. However, few reports are currently available regarding PET/CT findings in PPL. In this study, a 56-year old man with PPL was examined using FDG PET/CT imaging, which showed the unique intense uptake of FDG in the pancreas with atypical findings of malignancy in the CT scan and magnetic resonance images.

Usefulness of (18)F-FDG positron emission tomography/computed tomography for the diagnosis of pyothorax-associated lymphoma: A report of three cases.

Pyothorax-associated lymphoma (PAL) is a unique and rare non-Hodgkin's lymphoma developing in the pleural cavity following a long-standing history of chronic pyothorax (CP). The development of F-18 2'-deoxy-2fluoro-D-glucose (FDG) positron emission tomography combined with computed tomography (PET/CT) has contributed to the evaluation of lymphoma staging. However, only a few studies describing FDG-PET/CT findings in PAL have been published. This study reported three cases of PAL; all 3 patients had previously undergone artificial collapse therapy for pulmonary tuberculosis. Both the first case (an 84-year-old male) and second case (an 83-year-old male) complained of abdominal pain. An ultrasound scan revealed a mass shadow in the left chest wall without abnormal findings in the abdomen, and the CT and magnetic resonance imaging scans suggested malignant lymphoma of the left chest. FDG-PET/CT imaging showed extremely intense FDG uptake only in the left pleura and chest wall. Diagnosis was CP in the two patients, showing a high maximum standardized uptake value (SUVmax: early, 14.8 and delayed, 19.4 in the first case; early, 20.8 and delayed, 27.3 in the second case, respectively). Histopathological analysis of the specimens obtained by biopsy of the PET/CT-positive pleural mass showed non-Hodgkin's, diffuse large B cell lymphoma in the two cases. The third case was a 79-year-old male with relapse after right pleuropneumonectomy for PAL (diffuse large B cell lymphoma) 4 years earlier. PET/CT showed intense FDG uptake (SUVmax: early, 19.9 and delayed, 35.7) in the right pleura and chest wall. Diagnosis was CP, suggesting the recurrence of PAL. Furthermore, abnormal intense FDG uptake was noted in the hilar, mediastinal and supraclavicular lymph nodes, as well as in the spleen. In conclusion, FDG-PET/CT imaging is useful in the evaluation of the area of invasion in PAL.

Expression of centromere protein F (CENP-F) associated with higher FDG uptake on PET/CT, detected by cDNA microarray, predicts high-risk patients with primary breast cancer.

BACKGROUND: Higher standardized uptake value (SUV) detected by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) correlates with proliferation of primary breast cancer. The purpose of this study is to identify specific molecules upregulated in primary breast cancers with a high SUV and to examine their clinical significance. METHODS: We compared mRNA expression profiles between 14 tumors with low SUVs and 24 tumors with high SUVs by cDNA microarray. We identified centromere protein F (CENP-F) and CDC6 were upregulated in tumors with high SUVs. RT-PCR and immunohistochemical analyses were performed to validate these data. Clinical implication of CENP-F and CDC6 was examined for 253 archival breast cancers by the tissue microarray. RESULTS: The relative ratios of CENP-F and CDC6 expression levels to beta-actin were confirmed to be significantly higher in high SUV tumors than in low SUV tumors (p = 0.027 and 0.025, respectively) by RT-PCR. In immunohistochemical analysis of 47 node-negative tumors, the CENP-F expression was significantly higher in the high SUV tumors (74%) than the low SUV tumors (45%) (p = 0.04), but membranous and cytoplasmic CDC6 expressions did not significantly differ between both groups (p = 0.9 each). By the tissue microarray, CENP-F (HR = 2.94) as well as tumor size (HR = 4.49), nodal positivity (HR = 4.1), and Ki67 (HR = 2.05) showed independent impact on the patients' prognosis. CONCLUSION: High CENP-F expression, correlated with high SUV, was the prognostic indicators of primary breast cancer. Tumoral SUV levels may serve as a pretherapeutic indicator of aggressiveness of breast cancer.

Utility of 18F-fluoro-deoxyglucose emission tomography/computed tomography fusion imaging (18F-FDG PET/CT) in combination with ultrasonography for axillary staging in primary breast cancer.

BACKGROUND: Accurate evaluation of axillary lymph node (ALN) involvement is mandatory before treatment of primary breast cancer. The aim of this study is to compare preoperative diagnostic accuracy between positron emission tomography/computed tomography with 18F-fluorodeoxyglucose (18F-FDG PET/CT) and axillary ultrasonography (AUS) for detecting ALN metastasis in patients having operable breast cancer, and to assess the clinical management of axillary 18F-FDG PET/CT for therapeutic indication of sentinel node biopsy (SNB) and preoperative systemic chemotherapy (PSC). METHODS: One hundred eighty-three patients with primary operable breast cancer were recruited. All patients underwent 18F-FDG PET/CT and AUS followed by SNB and/or ALN dissection (ALND). Using 18F-FDG PET/CT, we studied both a visual assessment of 18F-FDG uptake and standardized uptake value (SUV) for axillary staging. RESULTS: In a visual assessment of 18F-FDG PET/CT, the diagnostic accuracy of ALN metastasis was 83% with 58% in sensitivity and 95% in specificity, and when cut-off point of SUV was set at 1.8, sensitivity, specificity, and accuracy were 36, 100, and 79%, respectively. On the other hand, the diagnostic accuracy of AUS was 85% with 54% in sensitivity and 99% in specificity. By the combination of 18F-FDG PET/CT and AUS to the axilla, the sensitivity, specificity, and accuracy were 64, 94, and 85%, respectively. If either 18F-FDG PET uptake or AUS was positive in allixa, the probability of axillary metastasis was high; 50% (6 of 12) in 18F-FDG PET uptake only, 80% (4 of 5) in AUS positive only, and 100% (28 of 28) in dual positive. By the combination of AUS and 18F-FDG PET/CT, candidates of SNB were more appropriately selected. The axillary 18F-FDG uptake was correlated with the maximum size and nuclear grade of metastatic foci (p = 0.006 and p = 0.03). CONCLUSION: The diagnostic accuracy of 18F-FDG PET/CT was shown to be nearly equal to ultrasound, and considering their limited sensitivities, the high radiation exposure by 18F-FDG PET/CT and also costs of the examination, it is likely that AUS will be more cost-effective in detecting massive axillary tumor burden. However, when we cannot judge the axillary staging using AUS alone, metabolic approach of 18F-FDG PET/CT for axillary staging would enable us a much more confident diagnosis.

Clinicopathological and prognostic relevance of uptake level using 18F-fluorodeoxyglucose positron emission tomography/computed tomography fusion imaging (18F-FDG PET/CT) in primary breast cancer.

OBJECTIVE: Using integrated 18F-fluorodeoxyglucose positron emission tomography/computed tomography fusion imaging (18F-FDG PET/CT), the clinical significance of 18F-FDG uptake was evaluated in patients with primary breast cancer. METHODS: Clinicopathological correlation with the level of maximum standardized uptake values (SUV) 60 min obtained from preoperative 18F-FDG PET/CT were examined in 152 patients with primary breast cancer. The prognostic impact of the level of SUV was explored using simulated prognosis derived from computed program Adjuvant! in 136 (89%) patients with invasive ductal carcinoma (IDC). RESULTS: High SUV level was significantly correlated with tumor invasive size (< or = 2 cm) (P < 0.0001), higher score of nuclear grade (P < 0.0001), nuclear atypia (P < 0.0001) and mitosis counts (P < 0.0001), negative hormone receptor status (P = 0.001), high score of c-erbB-2 expression (P = 0.006), lymph node metastasis (P = 0.002), and IDC in comparison with invasive lobular carcinoma (P = 0.004). Multivariate analyses showed tumor invasive size, nuclear grade and estrogen receptor negativity were significantly correlated with SUV in primary breast cancer (P < 0.0001,< 0.0001, and < 0.012, respectively), and nuclear grade was significantly correlated with SUV in tumors of invasive size 2 cm or less (P < 0.0001). Tumors with high SUV (cutoff value 4.0) showed higher relapse and mortality rate compared to those with low SUV (P < 0.0001). CONCLUSIONS: High uptake of 18F-FDG would be predictive of poor prognosis in patients with primary breast cancer, and aggressive features of cancer cells in patients with early breast cancer. 18F-FDG PET/CT could be a useful tool to pre-therapeutically predict biological characteristics and baseline risk of breast cancer.