Sentinel lymph node dissection combined with meticulous histology increases the detection rate of nodal metastases in prostate cancer

Purpose

To evaluate benefits of sentinel lymph node (SLN) biopsy for staging accuracy in prostate cancer. Extended pelvic lymph node dissection (ePLND) is a preferred staging tool; however, it may underestimate the incidence of nodal involvement.

Methods

Eighty patients with estimated risk of lymphadenopathy above 5 % based on Briganti nomogram had Tc-99m-labeled nanocolloid injected into the prostate. Planar lymphoscintigraphy and single-photon emission computed tomography/CT were performed to localize SLNs. Radioguided SLN dissection was followed by backup ePLND comprising external iliac, obturator and internal iliac regions. All SLNs were serially sectioned every 150 μm and examined using hematoxylin and eosin; immunohistochemical staining was applied every 300 μm.

Results

A total of 335 SLNs were detected, and 17 % were located outside ePLND template. Nodal metastases were diagnosed in 32 patients (40 %). Without radioguided SLN localization, solitary metastases posteriorly to the branches of the internal ilaic vessels, in pararectal and common iliac regions would not have been removed in five of 32 patients (16 %). Using standard histology protocol, we would have diagnosed metastases in 23 patients with median size of 2.8 mm. Serial sectioning of SLN and immunohistochemistry led to the detection of metastases in additional nine patients (28 %) with median size of 0.2 mm.

Conclusion

ePLND comprised 83 % of SLNs, at least one SLN laid outside its template in 28 % of patients. ePLND and SLN dissection combined with nodal serial sectioning and immunohistochemistry increased the detection rate of nodal metastases by 68 % in comparison with ePLND alone and standard histology protocol.     

Characteristics of Primary Papillary Thyroid Carcinoma with False-Negative Findings on Initial 18F-FDG PET/CT

Background

We often observe that uptake of tracer is not detected in the primary cancer focus in patients with histologically proven papillary thyroid carcinoma (PTC) on preoperative ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography (¹⁸F-FDG PET/CT). Therefore, we analyzed the clinical and pathologic variables affecting false-negative findings in primary tumors on preoperative ¹⁸F-FDG PET/CT.

Methods

We retrospectively reviewed the medical records of 115 consecutive patients who underwent ¹⁸F-FDG PET/CT for initial evaluation and were diagnosed with PTC by postoperative permanent biopsy. The clinical and pathologic characteristics that influence the ¹⁸F-FDG PET/CT findings in these patients were analyzed with respect to the following variables: age, gender, tumor size, multifocality of the primary tumor, perithyroidal invasion, lymphovascular or capsular invasion, and central lymph node metastasis-based final pathology.

Results

Twenty-six (22.6%) patients had false-negative ¹⁸F-FDG PET/CT findings. In patients with negative ¹⁸F-FDG PET/CT findings, tumor size, and perithyroidal and lymphovascular invasion were significantly less than in patients with positive ¹⁸F-FDG PET/CT findings. Tumors >1 cm in size were correlated with ¹⁸F-FDG PET/CT positivity. On multivariate analysis, perithyroidal invasion (P = 0.026, odds ratio = 7.714) and lymphovascular invasion (P = 0.036, odds ratio = 3.500) were independent factors for ¹⁸F-FDG PET/CT positivity. However, there were no significant differences between ¹⁸F-FDG PET/CT positivity and age, gender, capsular invasion, and central lymph node metastasis based on final pathology.

Conclusions

Tumor size and perithyroidal and lymphovascular invasion of papillary carcinoma can influence ¹⁸F-FDG PET/CT findings. Absence of perithyroidal and lymphovascular invasion were independent variables for false-negative findings on initial ¹⁸F-FDG PET/CT in patients with PTC.     

Role of the standardized uptake value of 18-fluorodeoxyglucose positron emission tomography–computed tomography in detecting the primary tumor and lymph node metastasis in colorectal cancers

Purpose

To assess the role of positron emission tomography–computed tomography (PET–CT) and multidetector-row CT (MD-CT) in detecting the primary lesion and lymph node metastasis in patients with colorectal cancers.

Methods

A collective total of 80 lesions resected from 77 patients were examined pathologically. We analyzed the significance of the standardized uptake value (SUV) and its relationship with the clinicopathologic findings of primary lesions and lymph node metastasis. The detectability of primary lesions and lymph node metastases on PET–CT images was compared with that on MD-CT images.

Results

The detectability of primary lesions was better on PET–CT images than on MD-CT images (p = 0.0023). We observed no significant differences in the SUV with respect to staging, tumor grade, lymphatic or vessel invasion, and macroscopic type; however, primary tumor size analysis revealed that tumors larger than 3 cm had a higher SUV than those smaller than 3 cm. The sensitivity of PET–CT for detecting lymph node metastasis was lower than that of MD-CT, but the specificity of PET–CT was higher than that of MD-CT.

Conclusions

The SUV of primary cancers tends to increase in proportion to tumor size. Although the value of PET–CT in detecting lymph node metastasis is limited, PET -positive lymph nodes can be considered metastatic.     

The prognostic value of lymph node staging with prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) and extended pelvic lymph node dissection in node-positive patients with prostate cancer

Objectives

To investigate whether patients with suspected pelvic lymph node metastases (molecular imaging [mi] N1) on staging prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) had a different oncological outcome compared to those in whom the PSMA PET/CT did not reveal any pelvic lymph node metastases (miN0).

Patients and Methods

All patients with pelvic lymph node metastatic (pN1) disease after robot-assisted radical prostatectomy (RARP) and extended pelvic lymph node dissection (ePLND) between January 2017 and December 2020 were included. To assess predictors of biochemical progression of disease after RARP, a multivariable Cox regression analysis was performed, including number of tumour-positive lymph nodes, diameter of the largest nodal metastasis, and extranodal extension.

Results

In total, 145 patients were diagnosed with pN1 disease after ePLND. The median biochemical progression-free survival in patients with miN0 on PSMA PET/CT was 13.7 months, compared to 7.9 months in patients with miN1 disease (P = 0.006). On multivariable Cox regression analysis, both number of tumour-positive lymph nodes (>2 vs 1–2: hazard ratio [HR] 1.97; P = 0.005) and diameter of the largest nodal metastasis (HR 1.12; P < 0.001) were significant independent predictors of biochemical progression of disease.

Conclusion

Patients in whom pelvic lymph node metastases were suspected on preoperative PSMA imaging (miN1), patients diagnosed with >2 tumour-positive lymph nodes, and patients with a larger diameter of the largest nodal metastasis had a significantly increased risk of biochemical disease progression after surgery.     

„Intermediate-risk-“ und „High-risk-Prostatakarzinompatienten“

Introduction

We examined the quantity and localization of pelvic lymph node (LN) metastases in patients undergoing extended pelvic lymphadenectomy (ePLND).

Materials and methods

A total of 174 patients with intermediate and high-risk prostate cancer underwent radical prostatectomy (RP) and ePLND. We analyzed the relationship between the number of LNs removed and the number, frequency and topography of LN metastases.

Results

In group 1 (intermediate risk patients, n=115) the average number of LNs removed was 20.5, LN metastases were found in 15 patients (13 %) and the localizations were in the external iliac artery 19 %, the internal iliac artery 32 %, the obturator foramen 36 %, the common iliac artery 7 %, Marcille’s triangle 3 % and sacral regions 3 %. In group 2 (high-risk patients, n=59) the average number of LNs removed was 23.9, LN metastases were found in 19 patients (32 %) and the localizations were the external iliac artery 15 %, the internal iliac artery 26 %, the obturator foramen 19 %, the common iliac artery 29 %, Marcille’s triangle 6 % and sacral regions 5 %. The full number of metastases was detected only if more than 15 LNs were removed in group 1 and 18 LNs in group 2.

Conclusions

At least 15 LNs in the intermediate risk group and at least 18 LNs in high risk group should be removed. The ePLND should include the common iliac artery, the internal iliac artery, Marcille’s triangle and sacral regions.     

Significant increase in detection of prostate cancer recurrence following radical prostatectomy with an early imaging acquisition protocol with <Superscript>18</Superscript>F-fluorocholine positron emission tomography/computed tomography

Purpose

To highlight a new imaging acquisition protocol during ¹⁸F-fluorocholine PET/CT in patients with biochemical recurrence after RP.

Methods

A total of 146 patients with PSA levels between 0.2 and 1 ng/ml with negative conventional imaging who did not receive salvage treatment were prospectively enrolled. Imaging acquisition protocol included an early dynamic phase (1–8 min), a conventional whole body (10–20 min), and a late phase (30–40 min). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were measured. Univariable and multivariable analyses were performed to identify independent predictors of positive PET/CT.

Results

The median trigger PSA was 0.6 ng/ml (IQR 0.43–0.76). Median PSA doubling time (PSA DT) was 7.91 months (IQR 4.42–11.3); median PSA velocity (PSAV) was 0.02 ng/ml per month (IQR 0.02–0.04). Overall, ¹⁸F-fluorocholine PET/CT was positive in 111 of 146 patients (76 %). Out of 111 positive examinations, 80 (72.1 %) were positive only in the early dynamic phase. Sensitivity, specificity, PPV, NPV, and accuracy were 78.9, 76.9, 97.2, 26.3, and 78.7 %, respectively. At multivariable logistic regression, trigger PSA ≥ 0.6 ng/ml [odds ratio (OR) 3.13; p = 0.001] and PSAV ≥ 0.04 ng/ml per month (OR 4.95; p = 0.004) were independent predictors of positive PET/CT. The low NPV remains the main limitation of PET/CT in this setting of patients.

Conclusions

The increased sensitivity, thanks to the early imaging acquisition protocol, makes ¹⁸F-fluorocholine PET/CT an attractive tool to detect prostate cancer recurrences in patients with a PSA level <1 ng/ml.

     

Die Positronenemissionstomographie zur präoperativen Lymphknotendiagnostik bei Ösophaguskarzinom

Background

Exact preoperative staging is a prerequisite for the indication and the choice of appropriate operative technique for patients with esophageal carcinoma. The objective of this prospective study was to assess whether positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) increases the accuracy of preoperative lymph node staging with standard computed tomography (CT) and thus leads to a different surgical approach.

Patients and methods

Fifty-eight patients with carcinoma of the esophagus (46 men and 12 women) with a median age of 61 years underwent FDG-PET imaging of the neck, chest, and abdomen as well as CT of the chest and abdomen. Sensitivity, specificity, and accuracy were calculated for both imaging techniques to evaluate the detection of histologically verified lymph node metastases.

Results

The FDG-PET showed higher specificity, whereas CT proved to be more accurate for detecting lymph node metastases not only of the abdomen (73% vs 59%) but also of the thorax (73% vs 63%). Resections were transhiatal in 23 patients and transthoracal in 16. As a supplement to conventional CT diagnostic procedure, FDG-PET was not decisive for the surgical approach.

Conclusions

Altogether, pretherapeutical PET imaging did not increase the accuracy of lymph node staging for our patients with esophageal carcinoma, which had already been defined through CT. Therefore, no new consequences resulted for the surgical procedure. Due to the high costs involved with PET investigation, lymph node staging with it is momentarily indicated mainly for clinical studies and when CT does not offer unequivocal results. Increased sensitivity of the already advantageous whole-body FDG-PET imaging by means of tumor-affinitive radiopharmaceuticals and optimized apparatus resolution could lead to new indications for this staging procedure.     

<Superscript>99m</Superscript>Tc-HDP bone scintigraphy and <Superscript>18</Superscript>F-sodiumfluoride PET/CT in primary staging of patients with prostate cancer

Introduction/Aim

Correct staging of patients with prostate cancer is important for treatment planning and prognosis. Although bone scintigraphy with ^99mTc-phosphonates (BS) is generally advised for staging by guidelines in high risk prostate cancer, this imaging technique is hampered by a high rate of inconclusive results and moderate accuracy. Potentially better imaging techniques for detection of bone metastases such as ¹⁸F-sodiumfluoride PET/CT (NaF PET/CT) are therefore being evaluated. In this observational cohort study we evaluate the performance and clinical impact of both BS and NaF PET/CT in primary staging of patients with prostate cancer.

Methods

The first of two cohorts consisted of patients who received a BS while the second included patients who received a NaF PET/CT for primary staging of prostate cancer. For both cohorts the number of positive, negative and equivocal findings, calculated diagnostic performance of the imaging modality in terms of sensitivity and specificity, as well as the impact on clinical management were studied. The ranges of the diagnostic performance were calculated both assuming that equivocal findings were positive and assuming that they were negative for bone metastases. For the NaF PET/CT cohort the number of patients with signs of lymph node metastases on low dose CT were also recorded, including the impact of these findings on clinical management.

Results

One-hundred-and-four patients underwent NaF PET/CT, whereas 122 patients underwent BS. Sensitivities of 97–100 and 84–95% and specificities of 98–100 and 72–100% were found on a patient basis for detection of bone metastases with NaF PET/CT and BS, respectively. Equivocal findings warranted further diagnostic procedures in 2% of the patients in the NaF cohort and in 16% in the BS cohort. In addition NaF PET/CT demonstrated lymph node metastases in 50% of the included patients, of which 25% showed evidence of lymph node metastases only.

Conclusion

Our data indicate better diagnostic performance of NaF PET/CT compared to BS for detection of bone metastases in primary staging of prostate cancer patients. Less equivocal findings are encountered with NaF PET/CT. Moreover, NaF PET/CT has additional value over BS since lymph node metastases are encountered frequently.

     

Utility of 18F-FDG PET/CT for Detecting Neck Metastasis in Patients with Salivary Gland Carcinomas: Preoperative Planning for Necessity and Extent of Neck Dissection

Background:

The precise diagnosis of cervical lymph node metastasis (CLNM) of salivary gland cancer is important to determine the surgical extent and adjuvant therapy. This study assessed the clinical utility of ¹⁸F-FDG PET in identifying CLNM in such patients.

Methods:

Fifty-four patients with intermediate or high-grade salivary gland cancer were preoperatively evaluated with ¹⁸F-FDG PET/CT and CT/MRI. Histopathologic analysis of neck dissection tissues was used as the gold standard for assessing imaging techniques. Tumor and nodal maximum standardized uptake values (SUVmax) were measured for each patient. Univariate and multivariate analyses were used to identify CLNM predictive factors.

Results:

Of the 54 patients, 24 patients (44 %) had CLNM. On a per-patient basis, the sensitivity and specificity of ¹⁸F-FDG PET/CT and CT/MRI were not significantly different (92 vs. 83 %, P = 0.625 and 93 vs. 97 %, P = 1.000, respectively). On a per-level basis, ¹⁸F-FDG PET/CT was significantly more sensitive and accurate than CT/MRI in the ipsilateral neck (96 vs. 54 %, P < 0.001 and 92 vs. 83 %, P < 0.001, respectively). The mean nodal SUVmax values of patients with and without nodal metastasis were 4.9 and 2.1, respectively (P = 0.008). Histologic grade was a significant predictor of CLNM (P = 0.014, odds ratio 14.46, 95 % confidence interval 1.73–120.79).

Conclusions:

¹⁸F-FDG PET/CT imaging and histologic grade are useful for detecting CLNM in patients with salivary gland carcinoma. This finding may guide preoperative planning for the necessity and extent of neck dissection in these patients.     

Early Assessment of Axillary Response with 18F-FDG PET/CT during Neoadjuvant Chemotherapy in Stage II–III Breast Cancer: Implications for Surgical Management of the Axilla

Background

If all initially node-positive patients undergo axillary lymph node dissection (ALND) after neoadjuvant chemotherapy (NAC), overtreatment may occur in patients with complete response. Positron emission tomography–computed tomography (PET/CT) during NAC may predict axillary response and select patients appropriate for less invasive treatment after NAC. We evaluated the value of sequential ¹⁸F fluorodeoxyglucose (FDG) PET/CTs during NAC for axillary response monitoring in stage II–III breast cancer.

Methods

A total of 219 PET/CTs were performed in 80 patients with cytology-proven, node-positive disease at baseline (PET/CT1, n = 80) and twice during NAC (PET/CT2 n = 62, PET/CT3, n = 77). The relative changes in maximum standardized uptake value (SUV_max) of axillary nodes were examined for their ability to assess pathological response. All patients underwent ALND after chemotherapy, and complete axillary response (pCR), defined as absence of isolated tumor cells and of micro- and macrometastases, served as the reference standard.

Results

A total of 32 (40 %) patients experienced axillary pCR. The relative decrease in SUV_max was significantly higher in patients with pCR than in those without, both on PET/CT2 (p < 0.001) and PET/CT3 (p = 0.025). The area under the receiver operating characteristic curve values for PET/CT2 and PET/CT3 were 0.80 (95 % confidence interval 0.68–0.92) and 0.65 (95 % confidence interval 0.52–0.79), respectively. A relative decrease of ≥60 % on PET/CT2 had an excellent specificity (35 of 37, 95 %), a high positive predictive value (12 of 14, 86 %), and a sensitivity of 48 %—that is, it accurately identified histologic pCR in 12 of 25 patients with disease that responded to therapy.

Conclusions

¹⁸F-FDG PET/CT early during NAC is useful for axillary response monitoring in cytology-proven node-positive breast cancer because it identifies pathological response, thus permitting ALND to be spared.     

18F-FAMT-PET Is Useful for the Diagnosis of Lymph Node Metastasis in Operable Esophageal Squamous Cell Carcinoma

Background

The role and potential usefulness of positron emission tomography (PET) scanning in certain tumors has been widely investigated in recent years. ¹⁸F-FAMT (L-[3-¹⁸F]-α-methyltyrosine) is an amino acid tracer for PET. This study investigated whether PET/CT with ¹⁸F-FAMT provides additional information for preoperative diagnostic workup of esophageal squamous cell carcinoma compared with that obtained by ¹⁸F-FDG (fluorodeoxyglucose) PET or CT.

Methods

PET/CT studies with ¹⁸F-FAMT and ¹⁸F-FDG were performed as a part of the preoperative workup in 21 patients with histologically confirmed esophageal squamous cell carcinoma.

Results

For the detection of primary esophageal cancer, ¹⁸F-FAMT-PET exhibited a sensitivity of 76.2%, whereas the sensitivity for ¹⁸F-FDG-PET was 90.5% (P = 0.214). ¹⁸F-FAMT uptake in primary tumors showed significant correlation with depth of invasion (P = 0.005), lymph node metastasis (P = 0.045), stage (P = 0.031), and lymphatic invasion (P = 0.029). In the evaluation of individual lymph node groups, ¹⁸F-FAMT-PET exhibited 18.2% sensitivity, 100% specificity, 71.9% accuracy, 100% positive predictive value, and 70.0% negative predictive value, compared with 24.2%, 93.7%, 69.8%, 66.6%, and 70.2%, respectively, for ¹⁸F FDG-PET. CT exhibited 39.4% sensitivity, 85.7% specificity, 69.8% accuracy, 59.1% positive predictive value, and 73.0% negative predictive value. The specificity of ¹⁸F-FAMT-PET is significantly higher than that of ¹⁸F-FDG-PET (P = 0.042) and CT (P = 0.002). ¹⁸F-FAMT-PET did not have any false-positive findings compared to those with ¹⁸F-FDG-PET.

Conclusions

Our findings suggest that the addition of ¹⁸F-FAMT-PET to ¹⁸F-FDG-PET and CT would permit more precise staging of esophageal cancer.     

Incidental Thyroid Carcinoma by FDG-PET/CT: A Study of Clinicopathological Characteristics

Background

The rising incidence of incidental thyroid carcinoma (ITC) detected during fluoro-2-deoxy-d-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) scanning poses a challenge to clinicians. The present study aims to critically evaluate the clinicopathological characteristics of ITC detected by FDG-PET/CT.

Methods

Among the 557 patients managed at our institution, 40 (7.2%) patients were identified as having ITC. Of these, 22 patients had their tumor detected by FDG-PET/CT (PET group) and 11 by ultrasonography (USG group). Additional bedside ultrasonography ± fine-needle aspiration (FNA) was done in all patients at their clinic visit. The clinicopathological characteristics were compared between the PET and USG groups.

Results

The PET group had significantly more patients with history of nonthyroidal malignancy (P < 0.001). Papillary carcinoma was the most common histological type in both groups. Despite having similar histological and prognostic features including tumor size, tumor multifocality, capsular invasion, extrathyroidal extension, and lymph node metastases, tumor bilaterality (or presence of contralateral tumor focus) was significantly more frequent in the PET than the USG group (P = 0.04). The tumors were also more advanced by the tumor–node–metastasis (TNM) staging system in the PET group (P = 0.021). None of the contralateral tumor foci were evident preoperatively. One patient in the USG group developed metastatic thyroid carcinoma in neck lymph nodes 28 months after thyroid resection.

Conclusion

ITC by FDG-PET/CT had higher incidence of tumor bilaterality than those detected by ultrasonography. Total thyroidectomy should be considered for ITC detected by FDG-PET/CT even for tumor size <10 mm.     

Diagnostic value of 18F-FDG PET/CT for lymph node metastasis of esophageal squamous cell carcinoma

Purpose

This study investigated the diagnostic accuracy of hybrid positron-emission tomography/computed tomography (PET/CT) for lymph node (LN) metastasis of esophageal cancer. We also investigated the correlation between the size of metastatic nests and the detection by PET/CT.

Methods

Two hundred and fifty-eight patients with esophageal squamous cell carcinoma who underwent esophagectomy with two- or three-field radical lymphadenectomy were analyzed retrospectively. We compared the diagnosis of preoperative PET/CT to the postoperative histopathological examination by each anatomical field (n = 1,231) in all 258 patients. The metastatic LNs resected from PET/CT positive fields were classified as belonging to the PET/CT-N-positive group (n = 229) and those from negative fields as belonging to the PET/CT-N-negative group (n = 352). The cross-sectional areas of metastatic nests were measured in each metastatic LN.

Results

Of the 1,231 fields, 275 (22 %) were positive for metastasis, including 581 LNs from 408 regional LN stations. The sensitivity and specificity of PET/CT examined by each anatomical field were 25.8 and 97.8 %, respectively. The median area of metastatic nests was 17.7 mm² in the PET/CT-N-positive group, and 7.7 mm² in the PET/CT-N-negative group (p < 0.001).

Conclusions

A significant correlation was suggested between the nest size and detection by PET/CT. Because of its low sensitivity, PET/CT alone is insufficient to determine the surgical procedures, especially when considering reduction surgery.     

Lymph-node metastases in rectal carcinoids

Background

Colorectal carcinoids are described as low-grade malignancy in the WHO classification. However, the survival is equally poor between carcinoids and adenocarcinomas if the tumors have lymph node metastasis or distant metastasis.

Patients and methods

We reviewed 17 patients with rectal carcinoid, who underwent surgical resection with lymph node dissection at our institution between March 2005 and November 2007. Our criteria for surgical resection were: tumor size of 10 mm or larger and positive resection margin or the presence of lymphovascular invasion in lesions to which endoscopic or surgical local treatment was carried out.

Results

Lymph node metastases were present in 12 patients. Three of them were with tumors less than 10 mm in size, of whom two patients had lymphovascular invasion. In eight out of the 12 with lymph node metastases, preoperative computed tomography (CT) identified lymph nodes of 5 mm or larger in size.

Conclusions

The present study demonstrated that rectal carcinoids with lymph node metastasis are common. Previously reported risk factors of lymph node metastasis in rectal carcinoid such as tumor size >?=?10 mm and lymphovascular invasion are useful in predicting lymph node metastasis. In addition, lymph nodes 5 mm or larger in size identified on preoperative CT suggest the presence of metastasis.     

The diagnostic accuracy of 18F-fluorodeoxyglucose positron emission tomography and computed tomography in staging bladder cancer: a single-institution study and a systematic review with meta-analysis

Purpose

The purpose of this study was to assess the diagnostic accuracy of 18F-fluorodeoxyglucose with positron emission tomography and computed tomography (FDG–PET–CT) to predict nodal metastases in patients with bladder cancer (BC) scheduled to undergo radical cystectomy (RC).

Methods

We retrospectively reviewed records of patients diagnosed with BC and scheduled to undergo RC at our center from January 2011 through February 2015, who also underwent FDG–PET–CT at the time of diagnosis. All patients underwent RC and an extended pelvic lymph node dissection as the reference standard. The primary endpoints were the sensitivity, specificity and overall accuracy of FDG–PET–CT in detecting lymph node metastasis. We also examined its accuracy in identifying distant metastasis. In addition, we conducted a protocol-driven systematic review and meta-analysis of accuracy of FDG–PET–CT for preoperative staging of BC, as compared to CT alone, as reported in individual studies. To assess the methodological quality of eligible studies, we used the QUADAS-2 tool (a revised tool for the Quality Assessment of Diagnostic Accuracy Studies) and pooled diagnostic accuracy measures using Meta-DiSc statistical software.

Results

For detecting nodal metastases in 78 patients, the sensitivity of FDG–PET–CT was 0.56 (95 % CI 0.29–0.80) and the specificity, 0.98 (95 % CI 0.91–1.00). Pooled sensitivity and specificity for detecting lymph node metastasis were 0.57 and 0.95, respectively. Positive likelihood ratio was 9.02. All lesions that were suspicious for distant metastasis were found to be positive on biopsy.

Conclusion

FDG–PET–CT was more accurate than CT alone in staging BC in patients undergoing surgery. Standardization of FDG–PET–CT protocol and cost-effectiveness analysis are required before widespread implementation of this technology.

     

Prediction of true-negative lymph node metastasis in clinical IA non-small cell lung cancer by measuring standardized uptake values on positron emission tomography

Purpose

We developed a method for predicting true-negative lymph node metastases in clinical IA non-small lung cancer (NSCLC) by the combined evaluation of computed tomography (CT), 2-[18F]-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) findings and the maximum standardized uptake value (SUVmax) of primary tumors.

Methods

The subjects of this study were 94 patients with clinical stage IA NSCLC who underwent both preoperative CT and FDG-PET. We analyzed the relationship between the SUVmax of primary tumors and various clinicopathological factors to find the best method available for assessing true-negative lymph node metastasis.

Results

The pathological stages were IA (n = 80), IB (n = 4), IIA (n = 5), IIIA (n = 4), and IV (n = 1). Pathologic lymph node metastasis was recognized in nine patients and the SUVmax of these tumors ranged from 3.3 to 20.3. A SUVmax of 3.0 was defined as the cut-off point and patients were dichotomized according to this point. Tumors with SUVmax of 3.0 or less were associated with a significantly lower incidence of pleural and vascular invasion and were characterized by the degree of differentiation.

Conclusion

The SUVmax of primary tumors reflects the grade of malignancy; therefore, the combined evaluation of FDG-PET/CT findings with the SUVmax of primary tumors may help predict lymph node metastasis negativity.     

Combined 18F‐fluorocholine and 18F‐fluoride positron emission tomography/computed tomography imaging for staging of high‐risk prostate cancer

Study Type – Diagnosis (cohort) Level of Evidence 2a What's known on the subject? and What does the study add? Positron emission tomography/computed tomography (PET/CT) with choline and fluoride for the detection of metastases in patients with prostate cancer have each been evaluated, with mixed results. Choline PET/CT has been evaluated against pelvic lymphadenectomy, generally with a low sensitivity but a high specificity; however, the study populations have been heterogenous. Fluoride PET/CT has been evaluated against other imaging methods, such as bone scan, single photon emission CT and MRI, and has been shown to have high specificity as well as sensitivity for bone metastases, but there are no studies with biopsy verification. This is the first study that evaluates the clinical use of both choline and fluoride PET/CT on the same patients in a well‐defined population of patients with high‐risk prostate cancer.

OBJECTIVE

• ? To investigate how often positron emission tomography/computed tomography (PET/CT) scans, with both ¹⁸F‐fluorocholine and ¹⁸F‐fluoride as markers, add clinically relevant information for patients with prostate cancer who have high‐risk tumours and a normal or inconclusive planar bone scan.

PATIENTS AND METHODS

• ? Patients with prostate cancer with prostate specific antigen (PSA) levels between 20 and 99 ng/mL and/or Gleason score 8–10 tumours, planned for treatment with curative intent based on routine staging with a negative or inconclusive bone scan, were further investigated with a ¹⁸F‐fluorocholine and a ¹⁸F‐fluoride PET/CT.
• ? None of the patients received hormonal therapy before the staging procedures were completed.

RESULTS

• ? For 50 of the 90 included patients (56%) one or both PET/CT scans indicated metastases.
• ? ¹⁸F‐fluorocholine PET/CT indicated lymph node metastases and/or bone metastases in 35 patients (39%).
• ? ¹⁸F‐fluoride PET/CT was suggestive for bone metastases in 37 patients (41%).
• ? In 18 patients (20%) the PET/CT scans indicated widespread metastases, leading to a change in therapy intent from curative to non‐curative.
• ? Of the patients with positive scans, 74% had Gleason score 8–10 tumours. Of the patients with Gleason score 8–10 tumours, 64% had positive scans.

CONCLUSIONS

• ? PET/CT scans with ¹⁸F‐fluorocholine and ¹⁸F‐fluoride commonly detect metastases in patients with high‐risk prostate cancer and a negative or inconclusive bone scan.
• ? For 20% of the patients the results of the PET/CT scans changed the treatment plan.

     

Impact of total PSA, PSA doubling time and PSA velocity on detection rates of 11C-Choline positron emission tomography in recurrent prostate cancer

Purpose

To evaluate the effect of total PSA (tPSA) and PSA kinetics on the detection rates of ¹¹C-Choline PET in patients with biochemical recurrence (BCR) after radical prostatectomy (RP) or external beam radiotherapy (EBRT).

Methods

We included 185 patients with BCR after RP (PSA >0.2 ng/ml) or after EBRT (ASTRO definition). After injection of 400 MBq ¹¹C-Choline i.v., a scan was made using the ECAT HR + PET camera with CT fusion images or Siemens mCT PET/CT. Biopsy-proven histology, confirmative imaging (CT or bone scan) and/or clinical follow-up (PSA) were used as composite reference. Statistical analysis was performed using PASW Statistics 18.

Results

¹¹C-Choline PET was positive in 124/185 cases (65 %) (in 22/61 (36 %) after RP, 102/124 (82 %) after EBRT). In 79 patients a local recurrence was identified, and 45 patients showed locoregional metastases on PET/CT. In 20 cases a proven false-negative PET scan was observed. Positive PET scans were confirmed by histology in 87/124 (70 %) cases, by confirmatory imaging in 34/124 (28 %) and by clinical follow-up after salvage treatment in 3 (2 %) cases. The ROC analysis to detect a recurrence showed significant difference in area under the curve (AUC) of tPSA 0.721(p < 0.001) and PSA velocity 0.730 (p < 0.001). PSA doubling time showed no significant difference with an AUC of 0.542 (p = 0.354). Detection rates are <50 % in tPSA <2 ng/ml and/or PSA velocity <1 ng/ml/year.

Conclusions

Total serum PSA and PSA velocity have significant effect on the detection rates of ¹¹C-Choline PET/CT in men with a BCR after RP or EBRT.     

18F-FDG Uptake at Initial Staging of the Adrenocortical Cancers: A Diagnostic Tool but Not of Prognostic Value

Background

Adrenocortical carcinoma (ACC) is a rare cancer for which little level evidence exists to guide management. ¹⁸F-FDG PET (¹⁸F-fluorodeoxyglucose positron emission tomography) is an increasingly used diagnostic tool in patients with suspicious or indeterminate adrenal tumors. In some other solid tumors, ¹⁸F-FDG PET may offer prognostic information that can guide optimal patient treatment. The aim of the present study was to evaluate whether preoperative ¹⁸F-FDG PET based on SUVs assessments has a prognostic value in ACC patients.

Methods

A retrospective analysis was performed in patients who underwent ¹⁸F-FDG PET/CT for the evaluation of ACC. Inclusion criteria were an unequivocal diagnosis of ACC; all data from primary diagnosis available; ¹⁸F-FDG PET/CT performed prior to surgery or other treatment of the primary tumor; a minimum of 6-months follow-up for surviving patients. All ¹⁸F-FDG PET/CT procedures were reinterpreted in a blind fashion.

Results

Thirty-seven patients (23 without metastasis [M0], 14 with metastasis [M1]) fulfilled the study criteria. Median uptake values were tumor standardized uptake values (SUV)_max = 11 (range: 3–56) and a tumor/liver SUV_max ratio = 4.2 (range: 1.3–15). Median follow-up was 20 months. Although classic risk factors (tumoral stage, Weiss score) were associated with poor outcome, there was no correlation between primary tumor FDG uptake with overall survival (OS) and disease free survival (DFS) in M0 patients and with overall survival in M1 patients. ¹⁸F-FDG uptake correlated inconsistently with sinister histological features, such as atypical mitoses or necrosis.

Conclusions

At initial staging, primary tumor FDG uptake in ACC patients does not correlate with OS and DFS at 2 years. Patient prognosis and treatment strategy should not be based on uptake values.     

Contribution of Computed Tomography to Ultrasound in Predicting Lateral Lymph Node Metastasis in Patients with Papillary Thyroid Carcinoma

Background

To evaluate the most accurate criteria using ultrasound (US) and contrast-enhanced computed tomography (CT) in predicting lateral lymph node metastasis in patients with papillary thyroid carcinoma (PTC).

Methods

A total of 122 lateral cervical lymph nodes of 113 patients diagnosed with PTC underwent preoperative US-guided fine-needle aspiration biopsy (US-FNAB) and CT. Degree of enhancement (DOE) was calculated by the differences of Hounsfield units (HU) between the lymph node and the ipsilateral sternocleiomastoideus muscle. Standard reference was set by surgical pathology results. Diagnostic performances of US, CT, and cutoff value for DOE were analyzed.

Results

Seventy lymph nodes (57.4%) were metastases, and 52 (42.6%) were benign. The cutoff value of DOE on CT was 35.7 HU. Diagnostic performance of CT including DOE of 35.7 HU was lower than US, but without significance (P = 0.321). When any suspicious CT feature was combined with the combination of suspicious US features, values of the area under the receiver operating characteristic curve decreased compared to the combinations of suspicious US features alone, 0.785 to 0.741, respectively (P = 0.225).

Conclusions

Contrast-enhanced CT does not greatly improve diagnostic values of US in the diagnosis of metastatic lateral cervical lymph nodes in patients with PTC.