Lymph node metastasis outside of a tumor-bearing lobe in primary lung cancer and the status of interlobar fissures: The necessity for removing lymph nodes from an adjacent lobe.

The new Tumor Node Metastasis staging system does not recognize fissure status with respect to adjacent lobe invasion (ALI) in lung cancer. Furthermore, no specific surgical strategies have been recommended for lymph node dissections around adjacent nontumor-bearing lobes (NTBLs) according to fissure status. Therefore, this study was undertaken to investigate the necessity of removing additional adjacent lobe lymph nodes in patients with nonsmall cell lung cancer (NSCLC) for lesions limited to in the vicinity of the interlobar fissure.From August 2013 to March 2015, the records of 332 patients, who underwent systematic mediastinal lymph node dissection, were reviewed in this retrospective study. The bronchial lymph nodes had been subjected to pathological examination, and the status of the fissures was also recorded. A statistical analysis was performed to identify the significant predictors of lymph node metastasis.The patients were divided into a nonadjacent lobe invasion (NALI) group (n = 295) and an ALI group (n = 37). There was a significant difference in tumors with pN2 disease between the ALI and NALI groups (37.8% vs 8.8%, P = .001). ALI tumors had significantly more frequent pleural involvement than NALI tumors (62.2% vs 43.1%, P = .035). The frequency of N2 involvement among tumors invading across the complete fissure was higher than that of the tumors invading across the incomplete fissure (44.4% vs 14.3%, P = .015). However, the frequency of N1 involvement among tumors invading across the incomplete fissure was not statistically different than that of tumors not invading across incomplete fissure (32.1% vs 24.2%, P = .357). Regarding lymph node metastasis in NTBL, 15 (12.7%) patients had lymph node metastases in NTBLs. Pleural involvement was an independent predictor of lymph node metastasis in an NTBL.A greater frequency of N2 lymph nodes existed in NSCLC with invading adjacent lobe across complete fissure, extensive lymphatic resection within the hilum, and NTBL in tumors with pleural involvement are justifiable and necessary.

Elevated serum CEA levels are associated with the explosive progression of lung adenocarcinoma harboring EGFR mutations.

BACKGROUND: Serum carcinoembryonic antigen (CEA) levels are a predictor of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) efficacy and are associated with epidermal growth factor receptor (EGFR) gene mutations. However, the clinical significance of plasma CEA level changes during different cycles of target therapy is unknown for lung adenocarcinoma patients with sensitizing EGFR mutations. METHODS: In total, 155 patients with lung adenocarcinoma were enrolled in this retrospective study between 2011 and 2015. EGFR mutations were detected by RT-PCR (real-time quantitative PCR). Plasma CEA levels were measured prior to different EGFR-TKI treatment cycles. Computed tomography (CT) scans were conducted every 2 months to assess the therapeutic efficacy. RESULTS: Serum CEA concentrations were significantly associated with EGFR mutations (p < 0.05). Furthermore, in all patients treated with EGFR-TKIs, the serum CEA levels increased with disease progression (p < 0.005). A COX multivariate analysis revealed that CEA levels 16.2 times above normal were associated with early disease progression (HR, 5.77; 95% CI:2.36 ~ 14.11; p < 0.001). Based on this finding, a threshold was set at the median time of 8.3 months. Patients with EGFR mutations exhibited a median progression-free survival time of 12.8 months. Serum CEA levels were markedly increased compared to levels measured 4.5 months prior to the changes detected via CT scans for patients resistant to EGFR-TKIs. CONCLUSIONS: Elevated CEA levels during targeted therapy may be a more sensitive predictor of explosive lung adenocarcinoma progression in patients harboring mutant EGFRs compared to traditional imaging methods.

A Pilot Study of 18F-Alfatide PET/CT Imaging for Detecting Lymph Node Metastases in Patients with Non-Small Cell Lung Cancer.

Angiogenesis plays a key role in tumor development and αvß3 integrin are overexpressed on the endothelial cell surface of newly forming vessels. 18F-Alfatide has favorable properties for αvß3 integrin targeting and showed potential for imaging angiogenesis with Positron Emission Tomography (PET)/computed tomography (CT). In this study, 13 patients with non-small cell lung cancer (NSCLC) who underwent 18F-Alfatide PET/CT before surgery were enrolled. The uptake of all dissected lymph nodes (LNs) of 18F-Alfatide were assessed visually and analyzed with a maximum and mean standard uptake value (SUVmax, SUVmean) and SUV ratios. LN metastases were pathologically confirmed and 20 of 196 LNs were malignant. All malignant LNs were successfully visualized on 18F-Alfatide PET/CT in patients and the sensitivity, specificity and accuracy was 100.0%, 94.9% and 95.4%, respectively. SUVmax, SUVmean and SUV ratios in malignant LNs were significantly higher than in benign LNs for NSCLC patients (P < 0.001). The same result was observed in patients with adenocarcinoma and squamous cell carcinoma (P < 0.001). The 18F-Alfatide parameter shows high sensitivity (83.9-100%), specificity (78.6-96.7%) and accuracy (81.7-96.9%) according to thresholds calculated from receiver operating characteristic curve. Our results suggest that 18F-Alfatide PET/CT is valuable in the diagnosis of metastatic LNs for NSCLC patients.

The clinical features, treatment, and prognosis of primary mediastinal malignant melanoma: A case report.

RATIONALE: Primary malignant melanoma (MM) of the mediastinum is exceedingly rare; a review of the English-language literature reveals only a small number of case reports. In this paper, we discuss a case of primary mediastinal MM and present a review of the relevant literature on its clinical features and treatment. PATIENT CONCERNS: A 52-year-old male presenting with back pain was admitted to our hospital for treatment. Imaging examination revealed an anterior mediastinal mass and no evidence of other metastatic or primary lesions. DIAGNOSES: After complete resection by video-assisted thoracoscopic surgery (VATS), histopathologic examination showed evidence of brown melanin pigment in the tumor cells, which were immunohistochemically positive for antimelanoma antibodies (HMB-45, Melan-A, S-100, and Ki67). INTERVENTIONS: Given the diagnosis of MM after surgery, the tumor was tested for the mutation in the BRAF gene (which encodes the serine/threonine-protein kinase B-raf) that leads to a V600E amino acid substitution, and the tumor was found to be wild type. Then the patient has been given immunotherapy. OUTCOMES: The patient completed 4 cycles of immunotherapy, and no recurrence or metastasis has been detected to date. LESSONS: In such cases, it is difficult to prove the primary nature of the intrathoracic melanoma. Moreover, preoperative identification of this disease is challenging, making misdiagnosis likely. Due to fast progression and poor prognosis, timely and effective systemic treatment is necessary to improve the outcomes for patients with primary mediastinal MM.

[Application of Non-intubated Anesthesia in VATS].

Tracheal intubation general anesthesia technique is widely used in video-assisted thoracic surgery (VATS) because it can improve the safety of VATS, but the complications of tracheal intubation can not be avoided. How to develop a "minimally invasive" surgery (including micro anesthesia) has become a hot topic in the field of minimally invasive surgery. Along with the progress of the anesthesia management technology and the risk management in the operation, the technology of non-intubated anesthesia was successfully applied to VATS, namely using local anesthesia to maintain patients intraoperative independent ventilation and intraoperative only mild sedation or fully conscious state of implementation of thoracoscope surgery, therefore is also called awake VATS. The anesthesia method not only reduces the anesthesia injury of tracheal intubation, but also conforms to the idea of rapid rehabilitation surgery. Based on non-intubated anesthesia in VATS in the brief history of development, the anesthesia selection, operation advantages and risks are reviewed in this paper.

Potential impact of (18)FDG-PET/CT on surgical approach for operable squamous cell cancer of middle-to-lower esophagus.

BACKGROUND: Fluorodeoxyglucose-positron emission tomography (PET)/computed tomography (CT) is reported to have a significant advantage over CT for staging esophageal cancer (EC). However, whether PET/CT may play a useful role in guiding surgical approach remains undetermined. METHODS: Patients with potentially resectable squamous cell EC were randomized into either PET/CT group or CT group. The surgical data and survival outcomes were compared. RESULTS: Compared to the CT group, the right-sided approach was more frequently used (42.6% versus 25.5%, P=0.065) in the PET/CT group in order to allow surgical access to radiographically suspicious lymph nodes inaccessible from the left, thus enabling the removal of more involved lymph nodes (2.83 versus 1.76; P=0.039) as well as their stations (1.65 versus 1.08; P=0.042). Although the overall survival between the two groups was similar, the PET/CT group had a longer disease-free survival (DFS) than the CT group (27.1 months versus 18.9 months; P=0.019), especially in the subgroup of node-positive patients (22.5 months versus 13.5 months; P=0.02). Preoperative imaging arm was the only prognostic factor found to independently influence DFS. CONCLUSION: For patients with middle-to-lower EC, surgical approaches directed by PET/CT may increase the likelihood of complete resection and affect DFS.

Epidermal growth factor receptor tyrosine kinase inhibitors with conventional chemotherapy for the treatment of non-small cell lung cancer.

We report a Chinese male patient with advanced stage lung squamous cell carcinoma who developed brain metastases after responding to treatment comprising six cycles of conventional chemotherapy with docetaxel and cisplatin. The patient was then treated with oral erlotinib (150 mg/day) and whole-brain radiation therapy followed by four cycles of docetaxel and carboplatin chemotherapy. The patient then received gefitinib (250 mg/day) as a maintenance therapy until the end of the follow-up period. In this patient, progression-free survival, defined as the interval from the initiation of first-line chemotherapy to the cessation of erlotinib due to progressive disease or death from any cause, was 3 months. Overall survival, defined as the interval from the initiation of first-line chemotherapy to death from any cause, was 75 months. Erlotinib was well tolerated in combination with whole-brain radiation therapy and a favorable objective response rate was observed. Furthermore, targeted drug treatment warrants consideration in patients with a negative epidermal growth factor receptor mutation status and male patients with a history of smoking.

Rapid on-site evaluation during endobronchial ultrasound-guided transbronchial needle aspiration for the diagnosis of hilar and mediastinal lymphadenopathy in patients with lung cancer.

The purpose of this study was to assess the usefulness of rapid on-site evaluation (ROSE) during endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and the interpretation of its results. Based on the criterion of using ROSE or not, 236 patients with known or suspected lung cancer undergoing EBUS-TBNA were allocated into the ROSE group (122 patients with 252 lymph nodes) and non-ROSE group (114 patients with 260 lymph nodes). In the ROSE group, the percentages of the suspicious specimens on cytology and non-diagnostic specimens on pathology were both significantly lower than that in the non-ROSE group (8.7% vs. 14.6%, p = 0.038; and 0.9% vs. 4.4%, p = 0.018, respectively), and 13 out of 22 suspicious lesions on ROSE were confirmed with definite diagnoses on TBNA pathology. The diagnostic yield stratified by pathology was significantly higher in the ROSE group than that in the non-ROSE group (90.5% vs. 81.2%, p = 0.003). These results suggest that ROSE during EBUS-TBNA allows for a low rate of suspicious results and therefore improves the diagnostic yield stratified by pathology when sampling hilar or mediastinal lymphadenopathy in patients with lung cancer.

Circulating Tumor Cell Analyses in Patients With Esophageal Squamous Cell Carcinoma Using Epithelial Marker-Dependent and -Independent Approaches.

In several epithelial malignancies, detection of circulating tumor cells (CTCs) in the peripheral blood has diagnostic, prognostic, and therapeutic implications. However, the clinical relevance of CTCs in esophageal squamous cell carcinoma (ESCC) has not yet been ascertained. The study was conducted with the aim of determining the clinical significance of CTCs in patients with ESCC by using 2 CTC detection systems, one epithelial marker-dependent and the other epithelial marker-independent. Paired peripheral blood samples were prospectively obtained from 61 ESCC patients before treatment and were analyzed for CTCs isolated by the CellSearch system (CS) and the method of isolation by size of epithelial tumor (ISET). Blood samples from 22 healthy volunteers were used as controls. Out of 61 study subjects, CTCs were detected in 20 patients (32.8%) by the ISET method and in only 1 patient (1.6%) by the CS method. Circulating tumor microemboli (CTM) were observed in 3 of 61 (4.9%) patients using ISET, but were undetectable in any of the patient by CS method. No CTCs/CTM were detected by either method in control groups. By ISET method, the presence of CTCs appeared to correlate with the stage of ESCC and with the baseline median platelet levels. No correlation with any other relevant clinicopathological variables was observed. Our results clearly indicate the ability of both CS and ISET methods to detect CTCs in peripheral blood samples from ESCC patients. However, the CellSearch system appears to have a poorer sensitivity as compared with the ISET method. Further studies are essential for assessing the role of such technologies in ESCC.

Proliferation PET image to characterize pathological spatial features in patients with non-small cell lung cancer: a pilot study.

PURPOSE: (18)F-FLT-PET imaging was proposed as a tool for measuring in vivo tumor cell proliferation and detecting sub-volumes to propose escalation in radiotherapy. The aim of this study was to validate whether high FLT uptake areas in (18)F-FLT PET/CT are coincident with tumor cell proliferation distribution indicated by Ki-67 staining in non-small cell lung cancer, thus provide theoretical support for the application of dose painting guided by (18)F-FLT PET/CT. MATERIALS AND METHODS: Twelve treatment naive patients with biopsy proven NSCLC underwent (18)F-FLT PET/CT scans followed by lobectomy were enrolled. The surgical specimen was dissected into 4-7 µm sections at approximately 4-mm intervals. The best slice was sort out to complete Ki-67 staining. Maximum Ki-67 labelling Index and SUVmax of the corresponding PET image was calculated. The correlation between Ki-67 Labelling Index and SUVmax of FLT was determined using Spearman Correlation analysis. High uptake areas and high proliferating areas were delineated on the two images, respectively, and their location was compared. RESULTS: The maximal SUV was 3.26 ± 0.97 (1.96-5.05), maximal Ki-67 labeling index was 49% ± 27.56% (5%-90%). Statistical analysis didn't reveal a significant correlation between them (r = -0.157, P = 0.627, > 0.05). 9 patients can contour high proliferating area on Ki-67 staining slice, and eight can contour the high uptake areas. In 4 patients, we can observe a generally close distribution of high uptake areas and high proliferating areas, in one patient, both the uptake level and proliferation status was low, while the others didn't not find a significant co-localization. CONCLUSION: Noninvasive (18)F-FLT PET assessing the proliferative status may be a valuable aid to guide dose painting in NSCLC, but it needs to be confirmed further.

Atlas of the thoracic lymph nodal delineation and recommendations for lymph nodal CTV of esophageal squamous cell cancer in radiation therapy from China.

PURPOSE: To construct an anatomical atlas of thoracic lymph node regions of esophageal cancer (EC) based on definitions from The Japan Esophageal Society (JES) and generate a consensus to delineate the nodal clinical target volume (CTVn) for elective nodal radiation (ENI) of esophageal squamous cell carcinoma (ESCC). METHODS AND MATERIALS: An interdisciplinary group including two dedicated radiation oncologists, an experienced radiologist, a pathologist and two thoracic surgeons were gathered to generate a three-dimensional radiological description for the mediastinal lymph node regions of EC on axial CT scans. Then the radiological boundaries of lymph node regions were validated by a relatively large number of physicians in multiple institutions. RESULTS: An atlas of detailed anatomic boundaries of lymph node station No. 105-114 was defined on axial CT, along with illustrations. From the previous work, the study provided a guide of CTVn contouring for ENI of thoracic ESCC from a single center. CONCLUSION: It is feasible to use such an atlas of thoracic lymph node stations for radiotherapy planning. A phase III study based on the atlas is ongoing in China to measure quantitatively the ENI received by patients with ESCC.

Abnormal expression of FLOT1 correlates with tumor progression and poor survival in patients with non-small cell lung cancer.

Recent studies have revealed that flotillin-1 (FLOT1) plays important roles in cancer progression. However, the role of FLOT1 in development and progression of non-small cell lung cancer (NSCLC) remains largely unknown. The objective of the current study was to investigate the expression pattern and clinicopathological significance of FLOT1 in patients with NSCLC. Real-time quantitative polymerase chain reaction was applied to examine FLOT1 mRNA expression in 52 pairs of NSCLC tissues and adjacent noncancerous tissues. Immunohistochemistry was performed to examine FLOT1 protein expression in paraffin-embedded tissues from 106 NSCLC patients. Statistical analyses were applied to evaluate the diagnostic value and associations of FLOT1 expression with clinicopathological characteristics. FLOT1 mRNA expression was evidently upregulated in NSCLC tissues compared with that in the adjacent noncancerous tissues. In the 106 cases of tested NSCLC samples, FLOT1 protein level was positively correlated with tumor size, tumor stage, and lymph node metastasis. Patients with higher FLOT1 expression had shorter overall survival time, whereas those with lower FLOT1 expression had longer survival time. Taken together, our findings indicate that FLOT1 may play an important role in NSCLC tumorigenesis. Further elucidation of the molecular mechanisms underlying the role of FLOT1 is warranted.

Giant malignant mesothelioma in the upper mediastinum: A case report.

Malignant mesothelioma in the mediastinum is rare and the majority of known cases have been reported as 'localized mesothelioma'. The present study reports a case of an upper mediastinal tumor, which was diagnosed through thoracoscopic surgery and surgical biopsies of the mass. A computed tomography scan revealed a giant upper mediastinal tumor, adjacent to the aortic arch, trachea, superior vena cava and left pulmonary artery. The vessels in the mediastinum were compressed and were shifted to the lower right. The trachea became stenotic and a small amount of bilateral pleural effusion was observed. The mass was relatively well encapsulated. There was no pleural thickening or clearly swollen lymph nodes in the mediastinum. The histopathological and immunohistochemical examinations of the tumor verified the diagnosis of a malignant mesothelioma. The tumor was demonstrated to be derived from the mediastinal pleural mesothelium cells. The patient received pemetrexed disodium and cisplatin combination chemotherapy for four cycles. At present, the patient is undergoing follow-up.

[Expression and significance of MAGE genes in human lung cancer].

Lung cancer is one of the common malignancies with an extremely poor prognosis, because of the current diagnostic techniques are not easy to find micrometastases. Melanoma associated antigens genes (MAGE) are tumor specific antigen genes, closely related to the occurrence, development and prognosis of lung cancer. The research of MAGE genes provide a new direction for the diagnosis and treatment of lung cancer.

Effects of different sequences of pulmonary artery and vein ligations during pulmonary lobectomy on blood micrometastasis of non-small cell lung cancer.

The aim of this study was to investigate the effects of different sequences of pulmonary artery and vein ligations during lobectomy on blood micrometastasis of non-small cell lung cancer (NSCLC). Cytokeratin 19 (CK19)/adhesion molecule CD44v6 mRNA were used as markers. A total of 30 NSCLC patients undergoing pulmonary lobectomy were randomly divided into pulmonary artery (PA)-first and pulmonary vein (PV)-first groups according to the order of artery or vein ligation (15 cases in each). Fluorescent quantitative-RT-PCR (FQ-RT-PCR) was used to detect the mRNA expression of CK19 and CD44v6 in pulmonary venous blood at the early and late periods during surgery, and ΔCt values were calculated. Meanwhile, the peripheral blood samples from 10 healthy volunteers were selected as the control. ΔCt values of CD44v6 and CK19 of NSCLC groups at the early period during surgery were 7.83±1.70 and 10.76±2.74, while those of the control group were 9.17±1.04 and 12.76±2.36. The expression of CD44v6 and CK19 genes in venous blood of NSCLC groups was significantly higher than that of the control group (P<0.05). In addition, the ΔCt values of CD44v6 and CK19 in the early and late periods during surgery in the PA-first group were 7.92±1.97 vs. 5.67±2.11 (P= 0.008) and 11.21±3.14 vs. 8.60±4.02 (P= 0.05), respectively. The expression of CD44v6 and CK19 in the late period were both significantly higher than those in the early period, while neither the ΔCt value of CD44v6 nor that of CK19 in the early vs. late periods in the PV-first group exhibited statistically significant differences (7.95±1.91 vs. 7.74±2.10 and 10.60±3.15 vs. 10.30±2.98) (P<0.05). Surgical manipulation itself may stimulate the occurrence of blood micrometastasis and the ligation of the PV first during surgery may help prevent blood micrometastasis.

Noninvasive evaluation of microscopic tumor extensions using standardized uptake value and metabolic tumor volume in non-small-cell lung cancer.

PURPOSE: To prospectively evaluate whether maximal microscopic extensions (MEmax) correlate with maximal standardized uptake value (SUVmax) and metabolic tumor volume (MTV) at 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) images in non-small-cell lung cancer (NSCLC). METHODS AND MATERIALS: Thirty-nine patients with Stage I-IIIA NSCLC underwent surgery after FDG-PET/CT scanning. SUVmax and MTV were calculated on the PET/CT images. The maximum linear distance from the tumor margin to the farthest extent of the tumor in every dimension was measured at the tumor section. The correlations among MEmax, SUVmax, MTV and other clinical pathologic parameters were analyzed. RESULTS: MEmax for all patients had a significant correlation with SUVmax (r = 0.777, p = 0.008) and MTV (r = 0.724, p < 0.001). When expressed in terms of the probability of covering ME with respect to a given margin, we suggested that margins of 1.93 mm, 3.90 mm, and 9.60 mm for SUVmax ≤ 5, 5-10, and >10 added to the gross tumor volume would be adequate to cover 95% of ME. CONCLUSIONS: This study demonstrated that tumors with high SUVmax and MTV have more MEmax and would therefore require more margin expansion from gross tumor volume to clinical target volume. FDG-PET/CT, especially for SUVmax, is promising and effective and merits additional study in noninvasive delimiting of the clinical target volume margin for NSCLC.

Comparison of (18)F-fluorothymidine and (18)F-fluorodeoxyglucose PET/CT in delineating gross tumor volume by optimal threshold in patients with squamous cell carcinoma of thoracic esophagus.

PURPOSE: To determine the optimal method of using (18)F-fluorothymidine (FLT) positron emission tomography (PET)/computed tomography (CT) simulation to delineate the gross tumor volume (GTV) in esophageal squamous cell carcinoma verified by pathologic examination and compare the results with those using (18)F-fluorodeoxyglucose (FDG) PET/CT. METHODS AND MATERIALS: A total of 22 patients were enrolled and underwent both FLT and FDG PET/CT. The GTVs with biologic information were delineated using seven different methods in FLT PET/CT and three different methods in FDG PET/CT. The results were compared with the pathologic gross tumor length, and the optimal threshold was obtained. Next, we compared the simulation plans using the optimal threshold of FLT and FDG PET/CT. The radiation dose was prescribed as 60 Gy in 30 fractions with a precise radiotherapy technique. RESULTS: The mean +/- standard deviation pathologic gross tumor length was 4.94 +/- 2.21 cm. On FLT PET/CT, the length of the standardized uptake value 1.4 was 4.91 +/- 2.43 cm. On FDG PET/CT, the length of the standardized uptake value 2.5 was 5.10 +/- 2.18 cm, both of which seemed more approximate to the pathologic gross tumor length. The differences in the bilateral lung volume receiving > or =20 Gy, heart volume receiving > or =40 Gy, and the maximal dose received by spinal cord between FLT and FDG were not significant. However, the values for mean lung dose, bilateral lung volume receiving > or =5, > or =10, > or =30, > or =40, and > or =50 Gy, mean heart dose, and heart volume receiving > or =30 Gy using FLT PET/CT-based planning were significant lower than those using FDG PET/CT. CONCLUSION: A standardized uptake value cutoff of 1.4 on FLT PET/CT and one of 2.5 on FDG PET/CT provided the closest estimation of GTV length. Finally, FLT PET/CT-based treatment planning provided potential benefits to the lungs and heart.

Comparison of tumor volumes as determined by pathologic examination and FDG-PET/CT images of non-small-cell lung cancer: a pilot study.

PURPOSE: To determine the cut-off standardized uptake value (SUV) on (18)F fluoro-2-deoxy-glucose (FDG) positron emission tomography/computed tomography (FDG-PET/CT) images that generates the best volumetric match to pathologic gross tumor volume (GTV(path)) for non-small-cell lung cancer (NSCLC). METHODS AND MATERIALS: Fifteen patients with NSCLC who underwent FDG-PET/CT scans followed by lobectomy were enrolled. The surgical specimen was dissected into 5-7-mum sections at approximately 4-mm intervals and stained with hematoxylin and eosin. The tumor-containing area was outlined slice by slice and the GTV(path) determined by summing over all the slices, taking into account the interslice thickness and fixation-induced volume reduction. The gross tumor volume from the PET images, GTV(PET), was determined as a function of cut-off SUV. The optimal threshold or optimal absolute SUV was defined as the value at which the GTV(PET) was the same as the GTV(path). RESULTS: The fixation process induced a volumetric reduction to 82% +/- 10% (range, 62-100%) of the original. The maximal SUV was 10.1 +/- 3.6 (range, 4.2-18.7). The optimal threshold and absolute SUV were 31% +/- 11% and 3.0 +/- 1.6, respectively. The optimal threshold was inversely correlated with GTV(path) and tumor diameter (p < 0.05), but the optimal absolute SUV had no significant correlation with GTV(path) or tumor diameter (p > 0.05). CONCLUSION: This study evaluated the use of GTV(path) as a criterion for determining the optimal cut-off SUV for NSCLC target volume delineation. Confirmatory studies including more cases are being performed.

Using 18F-fluorodeoxyglucose positron emission tomography to estimate the length of gross tumor in patients with squamous cell carcinoma of the esophagus.

PURPOSE: To determine the optimal method of using (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) to estimate gross tumor length in esophageal carcinoma. METHODS AND MATERIALS: Thirty-six patients with esophageal squamous cell carcinoma treated with radical surgery were enrolled. Gross tumor volumes (GTVs) were delineated using three different methods: visual interpretation, standardized uptake value (SUV) 2.5, and 40% of maximum standard uptake value (SUV(max)) on FDG-PET imaging. The length of tumors on PET scan were measured and recorded as Length(vis), Length(2.5), and Length(40), respectively, and compared with the length of gross tumor in the resected specimen (Length(gross)). All PET data were reviewed again postoperatively, and the GTV was delineated using various percentages of SUV(max). The optimal-threshold SUV was generated when the length of PET matched the Length(gross). RESULTS: The mean (+/-SD) Length(gross) was 5.48 +/- 1.98 cm. The mean Length(vis), Length(2.5), and Length(40) were 5.18 +/- 1.93 cm, 5.49 +/- 1.79 cm, and 4.34 +/- 1.54 cm, respectively. The mean Length(vis) (p = 0.123) and Length(2.5) (p = 0.957) were not significantly different from Length(gross), and Length(2.5) seems more approximate to Length(gross.) The mean Length(40) was significantly shorter than Length(gross) (p < 0.001). The mean optimal threshold was 23.81% +/- 11.29% for all tumors, and it was 19.78% +/- 8.59%, 30.92% +/- 12.28% for tumors >/=5 cm, and <5 cm, respectively (p = 0.009). The correlation coefficients of the optimal threshold were -0.802 and -0.561 with SUV(max) and Length(gross), respectively. CONCLUSIONS: The optimal PET method to estimate the length of gross tumor varies with tumor length and SUV(max); an SUV cutoff of 2.5 provided the closest estimation in this study.