Lymph node staging by positron emission tomography in patients with carcinoma of the cervix.

PURPOSE: The aim of this study was to compare the results of computed tomography (CT) and positron emission tomography (PET) with [18F]-fluoro-2-deoxy-D-glucose (FDG) for lymph node staging in patients with carcinoma of the cervix and to evaluate the relationship of the imaging findings to prognosis. PATIENTS AND METHODS: We retrospectively compared the results of CT lymph node staging and whole-body FDG-PET in 101 consecutive patients with carcinoma of the cervix. Patients were treated with standard irradiation and chemotherapy (as clinically indicated) and observed at 3-month intervals for a median of 15.4 months (range, 2.5 to 30 months). Progression-free survival was evaluated by the Kaplan-Meier method. RESULTS: CT demonstrated abnormally enlarged pelvic lymph nodes in 20 (20%) and para-aortic lymph nodes in seven (7%) of the 101 patients. PET demonstrated abnormal FDG uptake in pelvic lymph nodes in 67 (67%), in para-aortic lymph nodes in 21 (21%), and in supraclavicular lymph node in eight (8%). The 2-year progression-free survival, based solely on para-aortic lymph node status, was 64% in CT-negative and PET-negative patients, 18% in CT-negative and PET-positive patients, and 14% in CT-positive and PET-positive patients (P <.0001). A multivariate analysis demonstrated that the most significant prognostic factor for progression-free survival was the presence of positive para-aortic lymph nodes as detected by PET imaging (P =.025). CONCLUSION: This study demonstrates that FDG-PET detects abnormal lymph node regions more often than does CT and that the findings on PET are a better predictor of survival than those of CT in patients with carcinoma of the cervix.     

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

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

Positron emission tomography in limited-stage small-cell lung cancer: a prospective study.

PURPOSE: To determine how often positron emission tomography with [(18)F]fluoro-2-deoxy-D-glucose (FDG-PET) detects extensive-stage small-cell lung cancer (SCLC) in patients considered to have limited-stage disease based on conventional staging procedures, and to determine the impact of PET on treatment planning for presumed limited-stage SCLC. PATIENTS AND METHODS: We prospectively performed pretreatment FDG-PET on 24 patients determined by conventional staging methods to have limited-stage SCLC (defined as disease that could be encompassed within a reasonable radiotherapy portal, excluding bilateral supraclavicular disease). PET images were evaluated for evidence of extensive-stage disease. Tumor-node-metastasis system staging was also assigned for each patient, with and without PET information. RESULTS: FDG-PET demonstrated findings consistent with extensive-stage SCLC in three of 24 patients. FDG-PET correctly upstaged two (8.3%) of 24 patients to extensive-stage disease (95% CI, 1.03% to 27.0%). PET correctly identified tumor in each SCLC mass (primary or nodal) that was suspected on computed tomography (CT) imaging, thus giving a lesion-based sensitivity relative to CT of 100%. PET identified unsuspected regional nodal metastasis in six (25%) of 24 patients, and the radiation therapy plan was significantly altered to include the PET-positive/CT-negative nodes within the high-dose region in each of these patients. Brain PET images in 23 patients disclosed no evidence of brain metastasis. CONCLUSION: FDG-PET has high sensitivity for SCLC and appears to be of value for initial staging and treatment planning of patients with presumed limited-stage disease.     

The incremental effect of positron emission tomography on diagnostic accuracy in the initial staging of esophageal carcinoma

BACKGROUND: The purpose of the current study was to assess whether [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) provides incremental value (e.g., additional information on lymph node involvement or the presence of distant metastases) compared with computed tomography (CT) in patients with esophageal carcinoma. METHODS: The authors examined 149 consecutive patients with thoracic esophageal carcinoma. Eighty-one patients underwent radical esophagectomy without pretreatment, 17 received chemoradiotherapy followed by surgery, 3 underwent endoscopic mucosal resection, and the remaining 48 patients received definitive radiotherapy and chemotherapy. The diagnostic accuracy of FDG-PET and CT was evaluated at the time of diagnosis. RESULTS: The primary tumor was visualized using FDG-PET in 119 (80%) of 149 patients. Regarding lymph node metastases, FDG-PET had 32% sensitivity, 99% specificity, and 93% accuracy for individual lymph node group evaluation and 55% sensitivity, 90% specificity, and 72% accuracy for lymph node staging evaluation. PET exhibited incremental value over CT with regard to lymph node status in 14 of 98 patients who received surgery: 6 patients with negative CT findings were eventually shown to have lymph node metastases (i.e., they had positive PET findings and a positive reference standard [RS]); 6 patients with positive CT findings were shown not to have lymph node metastases (i.e., they had negative PET findings and a negative RS); and 2 patients were shown to have cervical lymph node metastases in addition to mediastinal or abdominal lymph node metastases. Among the remaining patients, PET showed incremental value over CT with regard to distant organ metastases in six patients. The overall incremental value of PET compared with CT with regard to staging accuracy was 14% (20 of 149 patients). CONCLUSIONS: FDG-PET provided incremental value over CT in the initial staging of esophageal carcinoma. At present, combined PET-CT may be the most effective method available for the preoperative staging of esophageal tumors.     

Value of [18F]fluorodeoxyglucose-positron emission tomography in managing patients with aggressive non-Hodgkin's lymphoma

An increased glucose metabolic rate is observed with various degrees of intensity in different subtypes of aggressive lymphomas. [(18)F]Fluorodeoxyglucose (FDG)-positron emission tomography (PET; FDG-PET) allows functional imaging of this phenomenon through 3-dimensional tomographic slices, which are now easily fused with computed tomography (CT) images. [(18)F]Fluorodeoxyglucose-PET staging appears superior to conventional staging modalities for detecting nodal and extranodal lymphoma. When performed after first-line chemotherapy, FDG-PET is more efficient than CT and conventional diagnostic methods to predict the disease outcome. Some studies have reported that the relapse rate is 100% in patients with positive PET findings after treatment and 17% in patients with negative PET findings. This imaging modality can also assess early response after 1-2 cycles of chemotherapy, thus identifying responders from patients whose cancer will fail to respond to first-line therapy or will relapse shortly after having exhibited a partial or complete remission. [(18)F]Fluorodeoxyglucose-PET also seems useful for an accurate selection of patients who will benefit from highly intensive treatment.     

FDG-PET evaluation of vaginal carcinoma

PURPOSE: To compare the results of CT and positron emission tomography (PET) and F-18 fluorodeoxyglucose (FDG) in the detection of the primary tumor and lymph node metastases in carcinoma of the vagina. METHODS AND MATERIALS: This was a prospective registry study of 23 consecutive patients with carcinoma of the vagina, in which we respectively compared the results of CT and whole-body FDG-PET. The tumor was clinical Stage II in 16 patients, Stage III in 6, and Stage IVa in 1 patient. The primary tumor ranged in size from 2 to 10 cm (mean 4.9), and 4 patients had palpable groin lymph nodes. All patients were treated with external beam radiotherapy and brachytherapy, 14 received concurrent chemotherapy, and 2 underwent primary tumor excision before the imaging evaluation. The median follow-up was 21 months in those patients alive without disease. Survival was estimated by the Kaplan-Meier method. RESULTS: Of the 21 patients with an intact primary tumor, CT visualized it in 9 (43%). CT also demonstrated abnormally enlarged groin lymph nodes in 3 patients and both groin and pelvic lymph nodes in 1 patient (4 of 23, 17%). FDG-PET identified abnormal uptake in all 21 intact primary tumors (100%). Abnormal uptake was found in the groin lymph nodes in 4 patients, pelvic lymph nodes in 2, and both groin and pelvic lymph nodes in 2 patients (8 of 23, 35%). The 3-year progression-free and overall survival estimate was 73% and 68%, respectively. CONCLUSION: The results of this study have demonstrated that FDG-PET detects the primary tumor and abnormal lymph nodes more often than does CT.     

2-(fluorine-18)fluoro-2-deoxy-D-glucose positron emission tomography in the detection and staging of malignant lymphoma. A bicenter trial

BACKGROUND: The authors undertook a prospective evaluation of the clinical value of 2-fluoro [18-]-2-deoxyglucose positron emission tomography (FDG-PET) in the detection and staging of malignant lymphoma compared with computed tomography (CT) and bone marrow biopsy (BMB). METHODS: Fifty-two consecutive patients with untreated malignant lymphoma were evaluated prospectively in a bicenter study. FDG-PET, CT, and BMB were performed for investigating lymph node/extranodal manifestations and bone marrow infiltration. Thirty-three percnt of the discrepant results were verified by biopsy, magnetic resonance imaging, or clinical follow-up (range, 4-24 month). RESULTS: Altogether, 1297 anatomic regions (lymph nodes, organs, and bone marrow) were evaluated. FDG-PET and CT scans were compared by receiver operating characteristic (ROC) curve analysis. The area under the ROC curve were as follows: lymph nodes, 0.996 (PET) and 0.916 (CT); extranodal, 0.999 (PET) and 0.916 (CT); supradiaphragmatic, 0.996 (PET) and 0.905 (CT); and infradiaphragmatic, 0.999 (PET) and 0.952 (CT). In these analyses, FDG-PET was significantly superior to CT (P < 0.05), except in infradiaphragmatic regions, in which the two methods produced equivalent results. In detecting bone marrow infiltration, FDG-PET was superior to CT and was equivalent to BMB. In 4 of 52 patients (8%), FDG-PET led to an upstaging and a change of therapy. CONCLUSIONS: Noninvasive FDG-PET is very accurate in the staging of malignant lymphoma. Compared with standard staging modalities (CT and BMB), PET was significantly superior and led to changes in the therapy regimen for 8% of patients.     

Pilot Study of [18F] Fluorodeoxyglucose Positron Emission Tomography (FDG-PET)/Magnetic Resonance Imaging (MRI) for Staging of Muscle-invasive Bladder Cancer (MIBC)

IntroductionComputed tomography (CT) has limited diagnostic accuracy for staging of muscle-invasive bladder cancer (MIBC). [¹⁸F] Fluorodeoxyglucose positron emission tomography (FDG-PET)/magnetic resonance imaging (MRI) is a novel imaging modality incorporating functional imaging with improved soft tissue characterization. This pilot study evaluated the use of preoperative FDG-PET/MRI for staging of MIBC.Patients and MethodsTwenty-one patients with MIBC with planned radical cystectomy were enrolled. Two teams of radiologists reviewed FDG-PET/MRI scans to determine: (1) presence of primary bladder tumor; and (2) lymph node involvement and distant metastases. FDG-PET/MRI was compared with cystectomy pathology and computed tomography (CT).ResultsEighteen patients were included in the final analysis, most (72.2%) of whom received neoadjuvant chemotherapy. Final pathology revealed 10 (56%) patients with muscle invasion and only 3 (17%) patients with lymph node involvement. Clustered analysis of FDG-PET/MRI radiology team reads revealed a sensitivity of 0.80 and a specificity of 0.56 for detection of the primary tumor with a sensitivity of 0 and a specificity of 1.00 for detection of lymph node involvement when compared with cystectomy pathology. CT imaging demonstrated similar rates in evaluation of the primary tumor (sensitivity, 0.91; specificity, 0.43) and lymph node involvement (sensitivity, 0; specificity, 0.93) when compared with pathology.ConclusionsThis pilot single-institution experience of FDG-PET/MRI for preoperative staging of MIBC performed similar to CT for the detection of the primary tumor; however, the determination of lymph node status was limited by few patients with true pathologic lymph node involvement. Further studies are needed to evaluate the potential role for FDG-PET/MRI in the staging of MIBC.     

Impact of FDG-PET/CT imaging on nodal staging for head-and-neck squamous cell carcinoma

PURPOSE: To evaluate the impact of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging on nodal staging for head-and-neck squamous cell carcinoma (SCC). METHODS AND MATERIALS: The study population consisted of 23 patients with head-and-neck SCC who were evaluated with FDG-PET/CT and went on to neck dissection. Two observers consensually determined the lesion size and maximum standardized uptake value (SUVmax) and compared the results with pathologic findings on nodal-level involvement. Two different observers (A and B) independently performed three protocols for clinical nodal staging. Methods 1, 2, and 3 were based on conventional modalities, additional visual information from FDG-PET/CT images, and FDG-PET/CT imaging alone with SUV data, respectively. RESULTS: All primary tumors were visualized with FDG-PET/CT. Pathologically, 19 positive and 93 negative nodal levels were identified. The SUVmax overlapped in negative and positive nodes <15 mm in diameter. According to receiver operating characteristics analysis, the size-based SUVmax cutoff values were 1.9, 2.5, and 3.0 for lymph nodes <10 mm, 10-15 mm, and >15 mm, respectively. These cutoff values yielded 79% sensitivity and 99% specificity for nodal-level staging. For Observer A, the sensitivity and specificity in Methods 1, 2, and 3 were 68% and 94%, 68% and 99%, and 84% and 99%, respectively, and Method 3 yielded significantly higher accuracy than Method 1 (p = 0.0269). For Observer B, Method 3 yielded the highest sensitivity (84%) and specificity (99%); however, the difference among the three protocols was not statistically significant. CONCLUSION: Imaging with FDG-PET/CT with size-based SUVmax cutoff values is an important modality for radiation therapy planning.     

Maximum standardized uptake value on PET/CT in preoperative assessment of lymph node metastasis from thoracic esophageal squamous cell carcinoma

The presence of lymph node metastasis is an important prognostic factor for patients with esophageal cancer. Accurate assessment of lymph nodes in thoracic esophageal carcinoma is essential for selecting appropriate treatment and forecasting disease progression. Positron emission tomography combined with computed tomography （PET/CT） is becoming an important tool in the workup of esophageal carcinoma. Here, we evaluated the effectiveness of the maximum standardized uptake value （SUVmax） in assessing lymph node metastasis in esophageal squamous cell carcinoma （ESCC） prior to surgery. Fifty-nine surgical patients with pathologically confirmed thoracic ESCC were retrospectively studied. These patients underwent radical esophagectomy with pathologic evaluation of lymph nodes. They all had 18F-FDG PET/CT scans in their preoperative staging procedures. None had a prior history of cancer. The pathologic status and PET/CT SUVmax of lymph nodes were collected to calculate the receiver operating characteristic （ROC） curve and to determine the best cutoff value of the PET/CT SUVmax to distinguish benign from malignant lymph nodes. Lymph node data from 27 others were used for the validation. A total of 323 lymph nodes including 39 metastatic lymph nodes were evaluated in the training cohort, and 117 lymph nodes including 32 metastatic lymph nodes were evaluated in the validation cohort. The cutoff point of the SUVmax for lymph nodes was 4.1, as calculated by ROC curve （sensitivity, 80%; specificity, 92%; accuracy, 90%）. When this cutoff value was applied to the validation cohort, a sensitivity, a specificity, and an accuracy of 81%, 88%, and 86%, respectively, were obtained. These results suggest that the SUVmax of lymph nodes predicts malignancy. Indeed, when an SUVmax of 4.1 was used instead of 2.5, FDG-PET/ CT was more accurate in assessing nodal metastasis.     

False-positive findings on [18F]FDG-PET caused by non-neoplastic cellular elements after neoadjuvant chemoradiotherapy for non-small cell lung cancer

We report two patients with non-small cell lung cancer who had a pathologically complete response after neoadjuvant chemoradiotherapy, although they had positive [(18)F]fluoro-deoxyglucose positron emission tomography ([(18)F]FDG-PET) scans. They underwent concurrent chemoradiotherapy, which resulted in a partial response determined by computed tomography (CT). While [(18)F]FDG-PET after chemoradiotherapy was positive, pathological examination showed that the tumors were fibrotic lesions with infiltration of lymphocytes and macrophages, with the appearance of metaplastic epithelial cells. The reasons for the false-positive results on [(18)F]FDG-PET were considered to be the high uptake of FDG in non-neoplastic inflammatory cellular elements, i.e. macrophages, lymphocytes and metaplastic epithelial cells, and squamous metaplasia induced by chemoradiotherapy. Although several studies demonstrated that [(18)F]FDG-PET could predict the response of neoadjuvant treatment of non-small cell lung cancer, one should bear in mind that false-positive results could be observed in pathological complete response of non-small cell lung cancer after neoadjuvant chemoradiotherapy.     

Value of positron emission tomography for lung cancer staging.

OBJECTIVE: The therapeutic strategy in non-small-cell lung cancer (NSCLC) requires exact staging of tumour invasion (T) as well as differentiation between ipsi- and contralateral lymph node invasion (N1/2 vs N3). [18F]FDG-positron emission tomography (FDG-PET) has been shown to detect invaded N with high accuracy while correct determination of T appears to be unclear. The purpose of this prospective study was to evaluate benefit and necessity of 18FDG-PET as an additive to conventional staging modalities. METHODS: Forty patients with suspected non-small-cell lung cancer (NSCLC) were staged by means of computed tomography (CT), bronchoscopy, mediastinoscopy and bone scintigraphy. Additionally, attenuation corrected FDG-PET of the thorax was performed pre-operatively for analysis of T and N topography. After surgical resection with radical lymphadenectomy T and N staging results of CT and PET were compared with the pathological diagnoses. Specificity, sensitivity, positive predictive value and accuracy of CT and PET were calculated. RESULTS: Twenty three squamous cell carcinomas, 14 adenocarcinomas, and three non-malignant tumours were found. Accuracy of CT-T was 0.75 and of PET-T 0.78; accuracy of CT-N was 0.78 and of PET-N 0.80. By combination of CT-T and PET-T accuracy was 0.88. Combination of CT-N and PET-N yielded an accuracy of 0.90. In two out of three cases, PET correctly determined T0. In two cases non-malignant inflammatory lymph nodes were falsely staged as malignant by PET. CONCLUSIONS: Adequate pre-operative T- and N-staging is possible with both CT and FDG-PET. Accuracy can be improved by combination of CT and FDG-PET. FDG-PET is superior to CT in order to differentiate between malignant and benign tumours. However, acute inflammation can mimic malignant lymph node invasion. FDG-PET is justified as a supporting staging measure in cases presenting unclear differentiation between N2 and N3 after conventional staging and is helpful in cases with unclear cell type of the primary tumour.     

Accuracy of positron emission tomography in mediastinal node assessment in coal workers with lung cancer

The purpose of this study was to explore the accuracy of ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) in the assessment of mediastinal lymph node in coal workers who had non-small cell lung cancer. We retrospectively reviewed 42 retired coal workers who had lung cancer without distant metastasis, between May 2007 and May 2010. Regarding the mediastinal lymph nodes, when the standard uptake value was greater than 2.5, it was considered “malignancy positive.” After histological examination of the mediastinal lymph nodes, anthracotic and metastatic ones were detected. The results of PET/CT were analyzed to determine its accuracy. Of these 42 patients, PET/CT detected 47 positive mediastinal lymph nodes in 24 patients with a mean SUV maximum of 6.2 (2.6–13.8). One hundred and thirty-one mediastinal lymph node foci were dissected. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FDG-PET/CT in detecting nodal metastases were 84% (16/19), 65% (15/23), 66% (16/24), 83% (15/18), and 74% (31/42) on a per-patient basis, respectively. Mediastinal node staging with FDG-PET/CT in coal workers is insufficient due to the high false-positive rates due to the presence of pneumoconiosis. In these patients, an invasive technique such as mediastinoscopy seems mandatory for confirmation of ipsilateral or contralateral mediastinal lymph node metastasis.     

食管癌IMRT前FDG PET-CT显像对治疗决策的影响

目的 探讨食管癌初治患者IMRT前PET-CT显像对其治疗方案的影响。方法 回顾分析60例经食管镜检证实的食管癌患者,患者均为初次治疗,经常规影像检查后拟行IMRT。放疗前行PET-CT显像,观察是否有分期和治疗方案改变。结果 与常规影像比,PET-CT显像使12例患者分期发生改变(2例T期上调、6例N期上调、2例N期下调、2例M期上调)。3例患者由于新发现较多的远处转移,治疗方案由放疗改为化疗。PET-CT检查导致20例患者靶区改变,其中16例因发现更多转移淋巴结使靶体积增大,4例则排除了淋巴结转移使靶区缩小。结论 PET-CT对食管癌区域淋巴结和远处转移诊断有一定优势,有助提高分期准确性,改变了部分患者治疗决策方案。     

Is there a role for FGD-PET in radiotherapy planning in esophageal carcinoma?

BACKGROUND AND PURPOSE: To determine the additional value of FDG-positron emission tomography (PET) to optimize delineation of the clinical target volume (CTV) in patients with advanced esophageal carcinoma. METHODS AND MATERIALS: The imaging and radiotherapy data from 30 patients with an advanced esophageal carcinoma were analysed. The lymph node classification for esophageal cancer was modified and translated into anatomical volumes on computed tomography (CT). The so defined 14 different regions were scored individually for lymph node involvement on CT, endoscopic ultrasound (EUS) and FDG-PET. The influence of discordant findings between conventional and functional imaging on the decision as to what should be irradiated was assessed. RESULTS: In 14 of the 30 patients (47%) discordances were found in detection of the pathological lymph nodes between CT/EUS and FDG-PET. In 8 patients, 9 lymph node regions were found with pathologic nodes on conventional imaging only. In three of these patients the influence of FDG-PET findings would have led to a decrease of the irradiated volume. In 6 patients, 8 lymph node regions were found with a normal CT/EUS and pathologic nodes on FDG-PET. In three of these patients (10%) the influence of the FDG-PET would have led to enlargement of the irradiated volume. CONCLUSIONS: The chance of a false negative result on FGD-PET is not negligible; therefore, the irradiated volume should not be reduced based on a negative FDG-PET in a region with suspect nodes on other investigations. However, due to the high specificity of FDG-PET enlarging the irradiated volume based on a positive FDG-PET in a region without suspected lymph nodes on CT and/or EUS should be considered. This indicates a role for FDG-PET in radiotherapy planning for esophageal cancer.     

Consistency of FDG-PET accuracy and cost-effectiveness in initial staging of patients with Hodgkin lymphoma across jurisdictions

IntroductionTwo hundred ten patients with newly diagnosed Hodgkin's lymphoma (HL) were consecutively enrolled in this prospective trial to evaluate the cost-effectiveness of fluorine-18 (¹⁸F)-fluoro-2-deoxy-D-glucose–positron emission tomography (FDG-PET) scan in initial staging of patients with HL.MethodsAll 210 patients were staged with conventional clinical staging (CCS) methods, including computed tomography (CT), bone marrow biopsy (BMB), and laboratory tests. Patients were also submitted to metabolic staging (MS) with whole-body FDG-PET scan before the beginning of treatment. A standard of reference for staging was determined with all staging procedures, histologic examination, and follow-up examinations. The accuracy of the CCS was compared with the MS. Local unit costs of procedures and tests were evaluated. Incremental cost-effectiveness ratio (ICER) was calculated for both strategies.ResultsIn the 210 patients with HL, the sensitivity for initial staging of FDG-PET was higher than that of CT and BMB in initial staging (97.9% vs. 87.3%; P < .001 and 94.2% vs. 71.4%, P < 0.003, respectively). The incorporation of FDG-PET in the staging procedure upstaged disease in 50 (24%) patients and downstaged disease in 17 (8%) patients. Changes in treatment would be seen in 32 (15%) patients. Cumulative cost for staging procedures was $3751/patient for CCS compared to $5081 for CCS + PET and $4588 for PET/CT. The ICER of PET/CT strategy was $16,215 per patient with modified treatment. PET/CT costs at the beginning and end of treatment would increase total costs of HL staging and first-line treatment by only 2%.ConclusionFDG-PET is more accurate than CT and BMB in HL staging. Given observed probabilities, FDG-PET is highly cost-effective in the public health care program in Brazil.     

A comparative study on the value of FDG-PET and sentinel node biopsy to identify occult axillary metastases.

BACKGROUND: Sentinel node biopsy (SNB) has become a standard treatment in staging axillary lymph nodes in early breast cancer. SNB, however, is an invasive procedure and is time-consuming when the sentinel node is analysed intra-operatively. Breast cancer is frequently characterised by increased 2-fluoro-2-deoxy-D-glucose uptake and many studies have shown encouraging results in detecting axillary lymph node metastases. The aim of this study was to compare SNB and -positron emission tomography (-PET) imaging, to assess their values in detecting occult axillary metastases. PATIENTS AND METHODS: In all, 236 patients with breast cancer and clinically negative axilla were enrolled in the study. 18-FDG-PET was carried out before surgery, using a positron emission tomography (PET)/computed tomography scanner. In all patients, SNB was carried out after identification through lymphoscintigraphy. Patients underwent axillary lymph nodes dissection (ALND) in cases of positive FDG-PET or positive SNB. The results of PET scan were compared with histopathology of SNB and ALND. RESULTS: In all, 103 out of the 236 patients (44%) had metastases in axillary nodes. Sensitivity of FDG-PET scan for detection of axillary lymph node metastases in this series was low (37%); however, specificity and positive predictive values were acceptable (96% and 88%, respectively). CONCLUSIONS: The high specificity of PET imaging indicates that patients who have a PET-positive axilla should have an ALND rather than an SNB for axillary staging. In contrast, FDG-PET showed poor sensitivity in the detection of axillary metastases, confirming the need for SNB in cases where PET is negative in the axilla.     

Whole-body diffusion-weighted magnetic resonance imaging: current evidence in oncology and potential role in colorectal cancer staging

Tumour staging in cancer patients generally entails a multimodality imaging approach. Whole-body (WB) imaging techniques may, however, be more time- and cost-effective than a multimodality approach. 2-Fluorine-18-fluoro-2-deoxy-d-glucose positron emission tomography (¹⁸FDG-PET), computed tomography (CT) and hybrid positron emission tomography and computed tomography (PET/CT) are the most established WB modalities, although new techniques, amongst which diffusion-weighted magnetic resonance imaging (DWI), are emerging. This review aims to evaluate the current evidence for WB-DWI in oncology, to discuss its potential for the WB staging of (colo)rectal cancer and to relate it to the established WB techniques.     

Positron emission tomography (PET) for staging low-grade non-Hodgkin's lymphomas (NHL)

Although positron emission tomography (PET) imaging is now recognized as a useful tool for staging intermediate and high-grade non-Hodgkin's lymphoma (NHL), few data are available regarding its accuracy in low grade NHL. We therefore studied 36 patients with histologically proven low-grade NHL. Whole-body 2-(fluorine-18) fluoro-2-deoxy-D-glucose (FDG) PET was performed at the time of initial diagnosis (n = 21) or for disease recurrence (n = 15) prior to any treatment. PET results were compared to those of physical examination and computed tomography (CT). PET studies were read without knowledge of any clinical data. Any focus of increased activity was described and given a probability of malignancy using a 5 point-scale (0: normal to 4: definitively malignant). An individual biopsy was available for a total of 31 lesions. The sensitivity and specificity were 87% and 100% for FDG-PET, 100% and 100% for physical examination and 90% and 100% for CT respectively. In addition, 42 of 97 peripheral lymph node lesions observed by FDG-PET were clinically undetected, whereas the physical examination detected 23 additional nodal lesions. PET and CT both indicated 12 extranodal lymphomatous localizations. FDG-PET showed 7 additional extranodal lesions while 5 additional unconfirmed lesions were observed on CT. Regarding bone marrow infiltration, PET and biopsy were concordant in 24 patients with 11 true positive (TP) and 13 true negative (TN). However PET was FN in 11 patients and no biopsy was performed in one patient. The combination PET/CT/physical examination seems to be more sensitive than the conventional approach for staging low grade NHL. Its sensitivity however is unacceptably low for diagnosing bone marrow infiltration.     

Whole-body 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) for accurate staging of Hodgkin's disease

Background: Staging of Hodgkin's disease (HD) is accomplished by a variety of invasive and non-invasive modalities. This prospective study was undertaken to investigate the value of whole-body positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) in defining regions involved by lymphoma compared with conventional staging methods in patients with HD.Patients and methods: Fourty-four newly diagnosed patients with HD underwent FDG-PET as part of their initial staging work-up. PET findings were correlated with findings of conventional staging including computed tomography, ultrasound, bone scanning, bone marrow biopsy, liver biopsy and laparotomy. When results of FDG-PET differed to those obtained by conventional methods reevaluation was performed by biopsy, if possible, or magnetic resonance imaging.Results: The results of FDG-PET were compared with three hundred twenty-one conventional staging procedures performed in 44 patients. FDG-PET was positive in 38 of 44 (86%) patients at sites of documented disease. PET detected additional lesions in five cases previously not identified by conventional staging methods. In another case a nodal lesion suspect on CT was negative at FDG-PET and was settled as true negative by biopsy. As a consequence of PET findings five patients had to be upstaged and one patient had to be downstaged, resulting in changes in treatment strategy in all six cases (14%). FDG-PET failed to visualize sites of HD in four patients. In two of our patients a false positive PET result was obtained.Conclusions: Our data indicate that FDG-PET provides an imaging technique that appears to visualize involved lesions in most patients with HD and is useful in the managment of these patients.