PET/CT assessment of neuroendocrine tumors of the lung with special emphasis on bronchial carcinoids

Orthopedic surgical treatment of osteomalacia induced by culprit soft tissue tumor in the hip region: a single-center retrospective study

BACKGROUND

Due to its occult position, complex anatomical structure, and spatial relationships, the causative tumor of Tumor-Induced Osteomalacia (TIO) in the hip region is quite difficult to detect and qualitatively diagnose in clinical practice. In this regard, clinicians often lack sufficient knowledge about such tumors, leading to frequent missed diagnoses, misdiagnoses, and unreasonable treatment.

OBJECTIVE

This study aimed to investigate the clinical characteristics of TIO patients with culprit soft tissue tumors in the hip region and evaluate the effect of surgical treatment on these individuals to improve clinicians' understanding of the rare phenomenon.

METHODS

The clinical data of all patients, from January 2013 to January 2023, who underwent surgical treatment for hip located culprit soft tissue tumors by the subspecialty group on bone and soft tissue tumors at our institution, were retrospectively analysed. Specifically, the clinical characteristics and therapeutic effects were examined and the patients' clinical experience was summarized.

RESULTS

Twenty-two patients, who met the inclusion criteria, were included. All patients experienced varying degrees of bone pain, commonly accompanied by weakness (16/22) and limited mobility (21/22), and 10 patients (45.5%) experienced a significant reduction in body height during the course of the disease. All patients underwent orthopedic surgery in the hip region, as hypophosphatemia occurred in all of them. Pathological diagnosis was confirmed to be consistent with causative tumors of TIO. All patients experienced a gradual increase in serum phosphorus postoperatively during short-term follow-up. The follow-up period was between 1 and 10 years, and the postoperative serum phosphorus levels were monitored at our hospital or other facilities close to the patients.

CONCLUSIONS

Oncogenic soft tissue tumors for TIO in the hip region are occult, making clinical misdiagnoses or missed diagnoses highly likely. Therefore, enhancing the clinician's understanding of this rare condition is imperative. Notably, for TIO patient whose culprit tumor can be located, complete surgical resection of the causative tumor is the best treatment option. Furthermore, close postoperative monitoring of serum phosphorus is necessary, and patients should be subjected to long-term follow-up for prompt detection of recurrent conditions.

Lung imaging methods: indications, strengths and limitations

Imaging methods are fundamental tools to detect and diagnose lung diseases, monitor their treatment and detect possible complications. Each modality, starting from classical chest radiographs and computed tomography, as well as the ever more popular and easily available thoracic ultrasound, magnetic resonance imaging and nuclear medicine methods, and new techniques such as photon counting computed tomography, radiomics and application of artificial intelligence, has its strong and weak points, which we should be familiar with to properly choose between the methods and interpret their results. In this review, we present the indications, strengths and main limitations of methods for chest imaging.

Preoperative evaluation and orthopedic surgical strategies for tumor-induced osteomalacia

Tumor-induced osteomalacia (TIO), also known as oncogenic osteomalacia, is very rare, with about 1000 reported cases globally. Removing most TIO culprit tumors requires the evaluation and intervention of orthopedic doctors. However, orthopedic doctors often have a poor understanding of the optical treatment of TIO due to its rarity. In addition, most TIO patients lack specific clinical manifestations. Also, the clinical localization and qualitative diagnosis of TIO are difficult and thus can easily be misdiagnosed and mistreated. Furthermore, the true incidence rate of TIO may be underestimated. Although many breakthroughs have been made in exploring the pathogenesis, clinical diagnosis, and treatment of TIO, rational and standardized orthopedic surgical treatment experience summary and sorting for TIO patients are lacking. In this article, the recent experience and progress in the field of orthopedic surgical treatment for TIO globally have been summarized, providing a theoretical basis and new clinical practice guidance for the rational treatment of TIO patients.

The diagnostic and prognostic role of combined [18F]FDG and [68Ga]-DOTA-peptides PET/CT in primary pulmonary carcinoids: a multicentric experience

OBJECTIVES

In the present retrospective multicentric study, we combined [68Ga]-DOTA-peptides and [18F]FDG-PET/CT findings aiming to investigate their capability to differentiate typical (TC) and atypical pulmonary carcinoids (AC) and their prognostic role.

METHODS

From three centers, 61 patients were retrospectively included. Based on a dual tracer combination we classified PET scans as score 1, [18F]FDG- and [68Ga]-DOTA-peptides negative; score 2, [68Ga]-DOTA-peptides positive and [18F]FDG-negative; score 3, [68Ga]-DOTA-peptides negative and [18F]FDG-positive; score 4, both tracers positive. Moreover, for each patient, the ratios of SUVmax on [68Ga]-DOTA-PET to that on [18F]FDG-PET were calculated (SUVr).

RESULTS

Thirty-five patients had a final diagnosis of TC. Twenty-two TC (57%) had positive [68Ga]-DOTA-peptides PET; instead, 21/26 (81%) AC had positive [18F]FDG-PET/CT. On dual-tracer analysis, scores 1, 2, 3 and 4 were 13%, 20%, 43% and 24% for all populations; 17%, 26%, 20% and 37% for TC; 8%, 11%, 73% and 8% for AC. Median SUVr was significantly higher in TC than AC (6.4 vs. 0.4, p = 0.011). The best value of SUVr to predict the final diagnosis was 1.05 (AUC 0.889). Relapse or progression of disease happened in 17 patients (11 affected by AC) and death in 10 cases (7 AC). AC diagnosis, positive [18F]FDG-PET, negative DOTA-PET and dual tracer score were significantly correlated with PFS (p = 0.013, p = 0.033, p = 0.029 and p = 0.019), while only AC diagnosis with OS (p = 0.022).

CONCLUSION

PET/CT findings had also a prognostic role in predicting PFS. Dual-tracer PET behavior may be used to predict the nature of pulmonary carcinoids and select the most appropriate management.

KEY POINTS

• Combination of [18F]FDG and [68Ga]-DOTA-peptides PET/CT results may help to differentiate between atypical and typical lung carcinoids. • The SUVmax ratio between [18F]FDG and [68Ga]-DOTA-peptides PET may help to differentiate between atypical and typical lung carcinoids. • Histotype and PET/CT features have a prognostic impact on PFS.

68Ga-Tetraazacyclododecane Tetraacetic Acid-DPhe1-Tyr3-Octreotate Positron Emission Tomography/Computed Tomographic Findings of Large-Cell Neuroendocrine Carcinoma of the Lung in a Child

Primary lung cancers in children are rare, and most children are diagnosed incidentally while being investigated for another medical problem. The diagnosis of primary lung tumors in children is very difficult because many children are asymptomatic until the advanced stages of the disease and nonspecific imaging findings. Although the usage of 68Ga-tetraazacyclododecane tetraacetic acid-DPhe1-Tyr3-octreotate (68Ga-DOTATATE) positron emission tomography/computed tomography (PET/CT) in adult patients is well known, it is a relatively new imaging modality for the pediatric patient group. Herein, we presented a unique case of large-cell neuroendocrine carcinoma of the lung in a child on 68Ga-DOTATATE PET/CT.

A Role of Non-FDG Tracers in Lung Cancer?

Since the introduction of PET/CT hybrid imaging about two decades ago the landscape of oncological imaging has fundamentally changed, opening a new era of molecular imaging with emphasis on functional characterization of biological processes such as metabolism, cellular proliferation, hypoxia, apoptosis, angiogenesis and immune response. The most commonly assessed functional hallmark of cancer is the increased metabolism in tumor cells due to well-known Warburg effect, because of which FDG has been the most employed radiotracer, the so-called pan-cancer agent, in oncological imaging. However, several limitations such as low specificity and low sensitivity for several histopathological forms of lung cancer as well as high background uptake in the normal tissue of FDG imaging lead to numerous serious pitfalls. This restricts its utilization and diagnostic value in lung cancer imaging, even though this is currently considered to be the method of choice in pulmonary cancer imaging. Accurate initial tumor staging and therapy response monitoring with respect to the TNM criteria plays a crucial role in therapy planning and management in patients with lung cancer. To this end, many efforts have been made for decades to develop novel PET radiopharmaceuticals with innovative approaches that go beyond the assessment of increased glycolytic activity alone. Radiopharmaceuticals targeting DNA synthesis, amino acid metabolism, angiogenesis, or hypoxia have been extensively studied, leading to the emergence of indications for specific clinical questions or as a complementary imaging tool alongside existing conventional or FDG imaging. Nevertheless, despite some initial encouraging results, these tracers couldn't gain a widespread use and acceptance in clinical routine. However, given its mechanism of action and some initial pilot studies regarding lung cancer imaging, FAPI has emerged as a very promising alternative tool that could provide superior or comparable diagnostic performance to FDG imaging in lung cancer entities. Thus, in this review article, we summarized the current PET radiopharmaceuticals, different imaging approaches and discussed the potential benefits and clinical applications of these agents in lung cancer imaging.

Correlation of somatostatin receptor PET/CT imaging features and immunohistochemistry in neuroendocrine tumors of the lung: a retrospective observational study

PURPOSE

To correlate somatostatin receptor (SSTR) and proliferative activity profile (SSTR2, SSTR5, Ki-67) at immunohistochemistry (IHC) with SSTR-PET/CT imaging features in a retrospective series of lung neuroendocrine tumors (NET). Proliferative activity by Ki-67 and ¹⁸F-FDG-PET/CT parameters (when available) were also correlated.

METHODS

Among 551 patients who underwent SSTR-PET/CT with ⁶⁸Ga-DOTA-somatostatin analogs (SSA) between July 2011 and March 2020 for lung neuroendocrine neoplasms, 32 patients with a confirmed diagnosis of NET were included. For 14 of them, ¹⁸F-FDG-PET/CT was available. PET/CT images were reviewed by qualitative and semi-quantitative analyses. Immunohistochemistry for SSTR2, SSTR5, and Ki-67 was assessed. Inferential analysis was performed including kappa statistics and Spearman's rank correlation test.

RESULTS

Definitive diagnosis consisted of 26 typical carcinoids-G1 and six atypical carcinoids-G2. Positive SSTR2-IHC was found in 62.5% of samples while SSTR5-IHC positivity was 19.4%. A correlation between SSTR2-IHC and SSTR-PET/CT was found in 24/32 cases (75.0%, p = 0.003): 20 were concordantly positive, 4 concordantly negative. For positive IHC, 100% concordance with SSTR-PET/CT (both positive) was observed, while for negative IHC concordance (both negative) was 33.3%. In 8 cases, IHC was negative while SSTR-PET/CT was positive, even though with low-grade uptake in all but one. A significant correlation between SUV_max values at SSTR-PET/CT and the SSTR2-IHC scores was found, with low SUV_max values corresponding to negative IHC and higher SUV_max values to positive IHC (p = 0.002).

CONCLUSION

This retrospective study showed an overall good agreement between SSTR2-IHC and tumor uptake at SSTR-PET/CT in lung NETs. SSTR-PET/CT SUV_max values can be used as a parameter of SSTR2 density. Within the limits imposed by the relatively small cohort, our data suggest that SSTR2-IHC may surrogate SSTR-PET/CT in selected lung NET patients for clinical decision making when SSTR-PET/CT is not available.

Value of [68Ga]Ga-somatostatin receptor PET/CT in the grading of pulmonary neuroendocrine (carcinoid) tumours and the detection of disseminated disease: single-centre pathology-based analysis and review of the literature

BACKGROUND

Although most guidelines suggest performing a positron emission tomography/computed tomography (PET/CT) with somatostatin receptor (SSTR) ligands for staging of pulmonary carcinoid tumours (PC), only a limited number of studies have evaluated the role of this imaging tool in this specific patient population. The preoperative differentiation between typical carcinoid (TC) and atypical carcinoid (AC) and the extent of dissemination (N/M status) are crucial factors for treatment allocation and prognosis of these patients. Therefore, we performed a pathology-based retrospective analysis of the value of SSTR PET/CT in tumour grading and detection of nodal and metastatic involvement of PC and compared this with the previous literature and with [18F]FDG PET/CT in a subgroup of patients.

METHODS

SSTR PET/CT scans performed between January 2007 and May 2020 in the context of PC were included. If available, [18F]FDG PET/CT images were also evaluated. The maximum standardized uptake (SUVmax) values of the primary tumour, of the pathologically examined hilar and mediastinal lymph node stations, as well as of the distant metastases, were recorded. Tumoural SUVmax values were related to the tumour type (TC versus AC) for both SSTR and [18F]FDG PET/CT in diagnosing and differentiating both tumour types. Nodal SUVmax values were compared to the pathological status (N+ versus N-) to evaluate the diagnostic accuracy of SSTR PET/CT in detecting lymph node involvement. Finally, a mixed model analysis of all pathologically proven distant metastatic lesions was performed.

RESULTS

A total of 86 SSTR PET/CT scans performed in 86 patients with PC were retrospectively analysed. [18F]FDG PET/CT was available in 46 patients. Analysis of the SUVmax values in the primary tumour showed significantly higher SSTR uptake in TC compared with AC (median SUVmax 18.4 vs 3.8; p = 0.003) and significantly higher [18F]FDG uptake in AC compared to TC (median SUVmax 5.4 vs 3.5; p = 0.038). Receiver operating characteristic (ROC) curve analysis resulted in an area under the curve (AUC) of 0.78 for the detection of TC on SSTR PET/CT and of 0.73 for the detection of AC on [18F]FDG PET/CT. A total of 267 pathologically evaluated hilar and mediastinal lymph node stations were analysed. ROC analysis of paired SSTR/[18F]FDG SUVmax values for the detection of metastasis of TC in 83 lymph node stations revealed an AUC of 0.91 for SSTR PET/CT and of 0.74 for [18F]FDG PET/CT (difference 0.17; 95% confidence interval - 0.03 to 0.38; p = 0.10). In a sub-cohort of 10 patients with 12 distant lesions that were pathologically examined due to a suspicious aspect on SSTR PET/CT, a positive predictive value (PPV) of 100% was observed.

CONCLUSION

Our findings confirm the higher SSTR ligand uptake in TC compared to AC and vice versa for [18F]FDG uptake. More importantly, we found a good diagnostic performance of SSTR PET/CT for the detection of hilar and mediastinal lymph node metastases of TC. Finally, a PPV of 100% for SSTR PET/CT was found in a small sub-cohort of patients with pathologically investigated distant metastatic lesions. Taken together, SSTR PET/CT has a very high diagnostic value in the TNM assessment of pulmonary carcinoids, particularly in TC, which underscores its position in European guidelines.

N-staging in large cell neuroendocrine carcinoma of the lung: diagnostic value of [18F]FDG PET/CT compared to the histopathology reference standard

Background

Large cell neuroendocrine carcinoma of the lung (LCNEC) is a rare entity occurring in less than 4% of all lung cancers. Due to its low differentiation and high glucose transporter 1 (GLUT1) expression, LCNEC demonstrates an increased glucose turnover. Thus, PET/CT with 2-[¹⁸F]-fluoro-deoxyglucose ([¹⁸F]FDG) is suitable for LCNEC staging. Surgery with curative intent is the treatment of choice in early stage LCNEC. Prerequisite for this is correct lymph node staging. This study aimed at evaluating the diagnostic performance of [¹⁸F]FDG PET/CT validated by histopathology following surgical resection or mediastinoscopy. N-staging interrater-reliability was assessed to test for robustness of the [¹⁸F]FDG PET/CT findings.

Methods

Between 03/2014 and 12/2020, 46 patients with LCNEC were included in this single center retrospective analysis. All underwent [¹⁸F]FDG PET/CT for pre-operative staging and subsequently either surgery (n = 38) or mediastinoscopy (n = 8). Regarding the lymph node involvement, sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated for [¹⁸F]FDG PET/CT using the final histopathological N-staging (pN0 to pN3) as reference.

Results

Per patient 14 ± 7 (range 4–32) lymph nodes were resected and histologically processed. 31/46 patients had no LCNEC spread into the lymph nodes. In 8/46 patients, the final stage was pN1, in 5/46 pN2 and in 2/46 pN3. [¹⁸F]FDG PET/CT diagnosed lymph node metastasis of LCNEC with a sensitivity of 93%, a specificity of 87%, an accuracy of 89%, a PPV of 78% and a NPV of 96%. In the four false positive cases, the [¹⁸F]FDG uptake of the lymph nodes was 33 to 67% less in comparison with that of the respective LCNEC primary. Interrater-reliability was high with a strong level of agreement (κ = 0.82).

Conclusions

In LCNEC N-staging with [¹⁸F]FDG PET/CT demonstrates both high sensitivity and specificity, an excellent NPV but a slightly reduced PPV. Accordingly, preoperative invasive mediastinal staging may be omitted in cases with cN0 disease by [¹⁸F]FDG PET/CT. In [¹⁸F]FDG PET/CT cN1-cN3 stages histological confirmation is warranted, particularly in case of only moderate [¹⁸F]FDG uptake as compared to the LCNEC primary.

Bronchoscopic diagnosis and treatment of endobronchial carcinoid: case report and review of the literature

Carcinoid tumours are rare neuroendocrine neoplasms that mostly occur in younger adults with low tendencies to metastasise. Based on their histological characteristics, they are divided into typical and atypical subtypes. The most common presenting symptoms are due to central airway obstruction. The first step in the diagnostic assessment should be a computed tomography (CT) scan, as it provides information both for local tumour extent and lymph node involvement. Bronchoscopy is the main tool for histological confirmation, evaluation of bronchial wall invasion and removal of endobronchial manifestation with subsequent resolution of atelectasis. Endobronchial ultrasound may be necessary to rule out lymph node metastasis. Somatostatin receptor scintigraphy in combination with CT can rule out further metastatic disease.Surgical resection using parenchyma-sparing techniques remains the gold standard for treatment. For selected patients, endobronchial therapy could be an alternative for minimal invasiveness. Long-term follow-up is suggested due to the high likelihood of recurrence.Here, we describe our clinical experience in a 35-year-old male patient who originally presented with haemoptysis and a central polypoid tumour in the left main bronchus revealed by a CT scan. The histological characteristics were indicative of a typical carcinoid. The patient was treated using an endobronchial approach only. No complications and no recurrences have been observed in a follow-up of 2 years.

Pediatric applications of Dotatate: early diagnostic and therapeutic experience

In recent years, new somatostatin receptor agents (SSTRs) have become available for diagnostic imaging and therapy in neuroendocrine tumors. The novel SSTR ligand DOTA-DPhel-Tyr3-octreotate (Dotatate) in particular can be linked with ⁶⁸Gallium for diagnostic imaging purposes, and with the β-emitter ¹⁷⁷Lutetium for radiotherapy in the setting of neuroendocrine tumors. Dotatate imaging offers distinct advantages in the evaluation of neuroendocrine tumors compared to standard techniques, including greater target-to-background ratio and lesion conspicuity, high sensitivity/specificity, improved spatial resolution with positron emission tomography (PET)/CT or PET/MR, and decreased radiation exposure. Although currently off-label in pediatrics, Dotatate theranostics in children are being explored, most notably in the setting of neuroblastoma and hereditary neuroendocrine syndromes. This article provides a multicenter case series of Dotatate imaging and therapy in pediatric patients in order to highlight the spectrum of potential clinical applications.

(Radio)Theranostic Patient Management in Oncology Exemplified by Neuroendocrine Neoplasms, Prostate Cancer, and Breast Cancer

The role of nuclear medicine in the management of oncological patients has expanded during last two decades. The number of radiopharmaceuticals contributing to the realization of theranostics/radiotheranostics in the context of personalized medicine is increasing. This review is focused on the examples of targeted (radio)pharmaceuticals for the imaging and therapy of neuroendocrine neoplasms (NENs), prostate cancer, and breast cancer. These examples strongly demonstrate the tendency of nuclear medicine development towards personalized medicine.

Impact of 18F-FDG PET/CT in Staging Patients With Small Cell Lung Cancer: A Systematic Review and Meta-Analysis

Background: Molecular imaging methods are currently used in the management of patients with lung cancer. Compared to non-small cell lung cancer, less data are available about the impact of molecular imaging using fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in staging patients with small cell lung cancer (SCLC). Performing a systematic review and meta-analysis, we aimed to provide quantitative data about the impact of ¹⁸F-FDG PET/CT in staging SCLC.

Methods: A comprehensive literature search of studies on the use of ¹⁸F-FDG PET/CT in patients with SCLC was performed. Three different databases were screened (PubMed/MEDLINE, EMBASE, and Cochrane library databases) until June 2019. Only articles describing the impact of ¹⁸F-FDG PET/CT in staging patients with SCLC were selected. A pooled analysis evaluating the change of binary SCLC staging (limited-stage vs. extensive-stage disease) using ¹⁸F-FDG PET/CT was carried out.

Results: Nine articles including 721 patients with SCLC were included in the systematic review. Compared to conventional staging, a superior diagnostic accuracy of ¹⁸F-FDG PET/CT was found. A change of binary SCLC staging using ¹⁸F-FDG PET/CT was demonstrated in 15% (95% confidence interval, 9–21%) of patients with SCLC. Currently, it is not clearly demonstrated that the use of ¹⁸F-FDG PET/CT for staging may improve the survival outcome of patients with SCLC.

Conclusions:¹⁸F-FDG PET/CT is a useful molecular imaging method for staging patients with SCLC because it can change the management in a significant number of patients. More large prospective studies and cost-effectiveness analyses on the impact of ¹⁸F-FDG PET/CT in staging patients with SCLC are needed.

Incidentally Detected Malignancies in Lung Transplant Explants

Active malignancy diagnosed within 5 years is an absolute contraindication for lung transplantation. In this study, we evaluated the rate of incidental malignancies detected in explanted lungs at our institution and assessed the posttransplant survival in patients with nonsmall cell lung cancer (NSCLC).

Methods

A retrospective chart review of lung transplant recipients at our institution from February 1999 to June 2017 was conducted. A literature review was performed to evaluate the prevalence and survival outcomes in patients with unexpected malignancies.

Results

From 407 patients who underwent lung transplantation, 9 (2.2%) were discovered to have malignant neoplasms. There were 3 cases of adenocarcinoma, 3 cases of adenocarcinoma in situ, 2 cases of squamous cell carcinoma, and 1 case of metastatic renal cell carcinoma. An extensive literature review found 12 case reports or case series reporting malignancy discovered at the time of lung transplantation. The overall prevalence of incidental neoplasms among 6746 recipients is around 1.5% (n = 103). The most common neoplasms discovered included adenocarcinoma (n = 56, 54%) and squamous cell carcinoma (n = 29, 28%). The overall 3-year survival was 54.4% for patients with localized NSCLC compared to 5.7% for those with nonlocalized disease.

Conclusions

Unidentified malignancies occur despite aggressive radiographic surveillance with poor posttransplant outcomes in patients with advanced malignancy. Malignancy-related radiographic findings may be missed pretransplant secondary to architectural distortion of lung parenchyma related to end-stage lung disease or because of the critical timing of surgery when donor lungs are available.

F-FDG Uptake Is Predictive of Poor Survival After Surgery for Large-CellNeuroendocrine-Carcinomas of The Lung: A Bicentric Analysis

Introduction: Large cell neuroendocrine carcinoma (LCNEC) represents a relatively rare and poorly studied entity whose management is not clearly established. The aim of this study was to explore the relationship between preoperative 18F-FDG-PET results, pathological features and long-term survival in a large surgical cohort of LCNEC. Methods: From 06/08 to 06/17, the clinical, radiometabolic, pathological and surgical aspects of 121 LCNEC-patients surgically treated in 2 tertiary centers were retrieved. A Cox regression model was used to identify predictors of survival and Kaplan-Meier method to summarize overall survivals. Results: Mean age and male/female ratio were 63.4±8.3 and 3:1, respectively. The main clinical, radiometabolic and surgical characteristics are reported in Tab.1. Most patients were active/former smokers and presented symptoms at diagnosis. 18FDG-PET/Scan was performed in 65 patients (53.7%) with a mean SUVmax of 10.1 (SD±4.6). Higher SUVmax values (SUVmax >10) were detected in tumors with larger size (p=0.004), advanced p-Stages (p=0.019), presenting necrosis (p=0.077) and with positive staining for CD56 (p=0.025) and TTF-1 (0.063). After surgery (R0 in 91% of cases), 52 (43%) patients had pStage-I while about 35% of patients presented with N1-2 disease. Median, 3-yrs and 5-yrs overall survival was 40 months, 52.2% and 44.6%, respectively. At univariate analysis, the survival was significantly influenced by SUVmax values (p=0.009) and by the presence of vascular invasion at pathological examination (p=0.024). Multivariate analysis showed as the FDG-SUVmax was the only independent variable affecting long-term survival (HR:2.86;C.E.: 1.09-7.47;p=0.032). Conclusions: Patients underwent surgical resection for LCNEC of the lung experienced a poor prognosis (5-yrs survival = 44.6% in this study). High-level FDG accumulation (SUVmax >10) correlates with pathological features and results to be independently predictive of poor survival after surgery. This parameter should be taking into account when planning the best strategy of care.

Endobronchial and surgical treatment of pulmonary carcinoid tumors: A systematic literature review

The treatment of pulmonary carcinoid has changed over the last decades. Although surgical resection is still the gold standard, minimally invasive endobronchial procedures have emerged as a parenchyma sparing alternative for tumors located in the central airways. This review was performed to identify the optimal treatment strategy for pulmonary carcinoid, with a particular focus on the feasibility and outcome of parenchyma sparing techniques versus surgical resection. A systematic review of the literature was carried out using MEDLINE, Embase and the Cochrane databases, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement. Two separate searches of publications in endobronchial and surgical treatment in patients with pulmonary carcinoid, were performed. Outcomes were overall survival, disease free survival, recurrence rate, complications, quality of life, and healthcare costs. Combining the two main searches for endobronchial therapy and surgical therapy yielded 3111 records. Finally, 43 studies concerning surgical treatment and 9 studies related to endobronchial treatment for pulmonary carcinoid were included. Assessment of included studies showed that lymph node involvement, histological grade, tumor location and tumor diameter were identified as poor prognostic factors and seem to be important for patients with pulmonary carcinoid. For patients with a more favorable prognosis, tumor location and tumor diameter are important factors that can help decide on the optimal treatment strategy. Centrally located small intraluminal pulmonary carcinoids, without signs of metastasis can be treated with minimally invasive alternatives such as endobronchial treatment or parenchyma sparing surgical resection. Patients with parenchyma sparing resections should be followed with long term follow up to exclude recurrence of disease. In a multidisciplinary setting, it should be determined whether individual patients are eligible for parenchyma sparing procedures or anatomical resection. Overall evidence is of low quality and future studies should focus on prospective trials in the treatment of pulmonary carcinoid.

Molecular imaging and therapy of somatostatin receptor positive tumors

Somatostatin receptors (SSTR) are upregulated in the cells of origin that define numerous neuroendocrine neoplasms. PET imaging with ⁶⁸Ga-DOTATATE allows specific targeting of SSTR2A, a single species of SSTR receptor, which is commonly overexpressed in a variety of gastroenteropancreatic neuroendocrine tumors, as well as pulmonary carcinoid and head and neck tumors. Due to more specific targeting of SSTR2 as well as lower radiation dose, shorter study length, ability to quantify uptake, and lower cost, ⁶⁸Ga-DOTATATE has demonstrated superior imaging attributes when compared to ¹¹¹In-pentetreotide. As with any novel imaging modality, dedicated training, increasing experience and staying up-to-date with scientific publications are required to provide optimal patient care. The purpose of this review is to summarize the current state of the art in SSTR-targeted molecular imaging and discuss ongoing and future potential diagnostic and therapeutic applications.

The future: diagnostic and imaging advances in MEN1 therapeutic approaches and management strategies

Prospective randomized data are lacking, but current clinical expert guidelines recommend annual screening examinations, including laboratory assessments and various imaging modalities (e.g. CT, MRI, scintigraphy and EUS) for patients with multiple endocrine neoplasia type 1 (MEN1). Routine screening is proposed to detect and localize neuroendocrine manifestations as early as possible. The goal is timely intervention to improve quality of life and to increase life expectancy by preventing the development of life-threatening hormonal syndromes and/or metastatic disease. In recent years, some studies compared different and new imaging methods regarding their sensitivity and utility in MEN1 patients. This present article reviews the proposed diagnostic tools for MEN1 screening as well as potential future perspectives.

[Pulmonary carcinoid tumors]

Pulmonary carcinoids are rare low-grade malignant tumors, which arise from the neuroendocrine system. Approximately 80% of all pulmonary carcinoid tumors are the relatively low-grade typical carcinoids and 20% are the more aggressive atypical carcinoids. Most carcinoids arise from the central airways and only a minority of carcinoids are found in the lung periphery. While most of the peripheral carcinoids are asymptomatic, central carcinoids are symptomatic and present with hemoptysis, wheezing or bronchial obstruction. On computed tomography (CT), carcinoids frequently present as hypervascular pulmonary nodules in close proximity to the bronchial system. Due to the bronchial obstruction, many patients with pulmonary carcinoids present with post-obstructive pneumonia or atelectasis. While fluorodeoxyglucose positron emission tomography CT (FDG-PET/CT) is of limited value in typical carcinoids due to the high rate of false negatives, somatostatin analogs are promising tracers in staging as well as in the planning of peptide receptor radionuclide therapy.

Second malignancy risk in patients with bronchopulmonary carcinoids: epidemiological results from Italian Network of Cancer Registries

PURPOSE

This epidemiological study aimed to determine the prevalence and characteristics of second tumors (STs) in patients with bronchopulmonary carcinoids (BCs).

METHODS

Data on neuroendocrine carcinomas (NECs) from the AIRTUM registry (1975-2011) were used for the analysis. Among 32,325 NECs, we focused our analysis on 3,205 patients (9.9%) affected by BCs. The overall ST number and incidence were calculated. The number of STs was compared with the expected cancer number in the healthy Italian population, and the standardized incidence ratio (SIR) and 95% confidence intervals were calculated.

RESULTS

The male/female ratio was 1.5:1 and the mean age 61.7 years (range: 7-94). A total of 640 STs were observed (overall incidence: 20%): 198 tumors were metachronous, 23 synchronous, and 419 occurred before the diagnosis of BC. The most common STs were bladder tumors (12.2%) followed by breast tumors (11.1%). We observed a large number of thyroid tumors (SIR = 3.88), with a remarkably higher frequency of thyroid tumors being synchronously detected with BC in female patients (SIR = 61.39). In male patients there was an increased frequency of urinary system tumors, in particular metachronous tumors of the kidney and renal pelvis (SIR = 3.34) and synchronous tumors of the urinary bladder (SIR = 11.48).

CONCLUSIONS

A high frequency of STs is predictable in patients with BCs, with synchronous thyroid tumors being observed in women and kidney and urinary bladder tumors in men. However, these data should be interpreted with caution, considering that the diagnosis of such tumors often occurs as an incidental finding during investigations for other malignancies.

Pediatric Neuroendocrine Carcinoid Tumors: Review of Diagnostic Imaging Findings and Recent Advances

OBJECTIVE

Although rare, pediatric neuroendocrine tumors including carcinoid tumor have increased in incidence over the past few decades. Despite increased recognition, survival rates have not significantly improved. Earlier detection of these tumors is necessary to improve clinical outcomes. This article discusses imaging approaches for detecting pediatric carcinoid tumors including anatomic imaging methods such as CT and MRI as well as functional imaging methods targeting the somatostatin receptor including ¹¹¹In-labeled octreotide and newer ⁶⁸Ga-based radiotracers that may hold promise in hybrid PET/CT or PET/MRI.

CONCLUSION

Improvements in functional imaging with novel somatostatin receptor-specific radiotracers along with fused functional and anatomic imaging have substantially improved the clinical detection of carcinoid tumors. Although rare, these tumors are encountered in children, and an awareness of the appropriate use of various imaging methods is essential for pediatric specialists. Further research is needed to ascertain the diagnostic value of newer imaging methods and radiotracer-based treatment approaches, especially in the pediatric population.

The Diagnosis and Treatment of Bronchopulmonary Carcinoid

BACKGROUND

The spectrum of primary neuroendocrine tumors of the lungs ranges from typical carcinoid tumors, which are relatively benign, to highly aggressive small-cell carcinoma. In this review, we summarize the treatment of bronchopulmonary carcinoid, a disease with an incidence of 0.5 per 100,000 persons per year in Western countries.

METHOD

We selectively searched the PubMed database for scientific evidence on the treatment of bronchopulmonary carcinoid, considering only articles published up to February 2015. We also performed a survival analysis of 84 patients with this disease who underwent interdisciplinary treatment at the University of Freiburg Medical Center.

RESULTS

Carcinoid tumors account for less than 1% of all lung tumors. They manifest themselves clinically with cough (35%), hemoptysis (25%), and/or bronchial obstruction (40%), depending on their location, size, and pattern of growth. 30% of patients are asymptomatic, and less than 1% have hormone-associated symptoms. Typical and atypical carcinoid tumors are distinguished on a histological basis; the histologic differential diagnosis also includes large-cell neuroendocrine tumors and small-cell carcinoma of the lung. 80% of patients who undergo resection of typical carcinoid tumors survive at least 10 years. Atypical carcinoid tumors recur more commonly than typical ones. If the mediastinal lymph nodes are involved, adjuvant treatment should be considered.

CONCLUSION

Because of their rarity, the treatment of bronchopulmonary carcinoid tumors presents an interdisciplinary challenge. Surgical resection, the treatment of choice for local carcinoid tumors, generally leads to long-term survival. The existing registers should be made more comprehensive so that the treatment of this disease can be better in the future.

Challenges in Interpretation of Staging PET/CT in Thoracic Malignancies

¹⁸F-fluorodeoxryglucose (¹⁸F-FDG) PET/CT imaging is routinely performed in the evaluation of patients with known or suspected thoracic malignancy. Indications for its use include staging of malignancy, assessment of response to therapy, evaluation of suspected disease recurrence, and evaluation of a solitary pulmonary nodule. In this article, we will discuss specific technical artifacts and also review potential pitfalls in the interpretation of PET/CT in thoracic malignancies including normal variations in physiologic uptake of FDG, benign conditions (such as infection, inflammation, posttreatment changes, and iatrogenic factors) that can result in increased FDG uptake, and malignancies that demonstrate scarce to no FDG uptake.

Growth hormone–secreting macroadenoma of the pituitary gland successfully treated with the radiolabeled somatostatin analog 90Y-DOTATATE: case report

Pituitary tumors causing acromegaly are usually macroadenomas at the time of diagnosis, and they can grow aggressively, infiltrating surrounding tissues. Difficulty in achieving complete tumor removal at surgery can lead toward a strong tendency for recurrence, making it necessary to consider a means of treatment other than those currently used such as somatostatin analogs (SSAs), growth hormone (GH) receptor antagonist, surgical removal, and radiotherapy. The purpose of this paper is to describe a patient diagnosed with an aggressive, giant GH-secreting tumor refractory to medical therapy but ultimately treated with the radiolabeled somatostatin analog 90Y-DOTATATE.

A 26-year-old male with an invasive macroadenoma of the pituitary gland (5.6 × 2.5 × 3.6 cm) and biochemically confirmed acromegaly underwent 2 partial tumor resections: the first used the transsphenoidal approach and the second used the transcranial method. The patient received SSAs pre- and postoperatively. Because of the progression in pituitary tumor size, he underwent classic irradiation of the tumor (50 Gy). One and a half years later, the patient presented with clinically and biochemically active disease, and the tumor size was still 52 mm in diameter (height). Two neurosurgeons disqualified him from further surgical procedures. After confirming the presence of somatostatin receptors in the pituitary tumor by using 68Ga-DOTATATE PET/CT, we treated the patient 4 times with an SSA bound with 90Y-DOTATATE. After this treatment, the patient attained partial biochemical remission and a reduction in the tumor mass for the first time.

Treatment with an SSA bound with 90Y-DOTATATE may be a promising option for some aggressive GH-secreting pituitary adenomas when other methods have failed.

Endobronchial Hamartoma Subtotally Occluding the Right Main Bronchus and Mimicking Bronchial Carcinoid Tumor

Hamartomas are very rarely identified as an endobronchial lesion. Herein, we describe a peculiar case of a 55-year-old woman with persistent cough and increasing dyspnea and radiological detection of a solid lesion subtotally occluding the main right bronchus. Despite the radiological and radiometabolic (18-fluoro-2-deoxy-d-glucose positron emission tomography/computer tomography scan) features were highly suspected for bronchial carcinoid, the definitive diagnosis after endoscopic removal was indicative of an endobronchial hamartoma. When considering differential diagnosis of an endobronchial lesion, the physicians should take firmly in mind such rare entity and, accordingly, bronchoscopy and bronchoscopic biopsy should be done as first step in management of all cases presenting with endobronchial lesions.

Challenges in the Diagnosis and Management of Well-Differentiated Neuroendocrine Tumors of the Lung (Typical and Atypical Carcinoid): Current Status and Future Considerations

Neuroendocrine tumors (NET) of the lung represent approximately 25% of all primary lung tumors and can be classified as low grade (typical carcinoids), intermediate grade (atypical carcinoids), or high grade (large cell neuroendocrine carcinoma or small cell lung carcinoma). Low- and intermediate-grade lung NET are increasingly recognized as biologically distinct from high-grade lung NET based on clinical behavior and underlying molecular abnormalities. This review summarizes current knowledge and challenges in the diagnosis and management of low- and intermediate-grade lung NET. Accurate histopathologic classification of lung NET is critical to determining appropriate treatment options but can be challenging even for experts. For low- and intermediate-grade lung NET, surgery remains the mainstay of treatment for localized disease. Although no standard systemic therapy has been established for the treatment of advanced, unresectable disease, a number of promising treatment options are emerging, including somatostatin analogs, temozolomide-based chemotherapy, targeted therapy with mammalian target of rapamycin or vascular endothelial growth factor inhibitors, and peptide receptor radionuclide therapy. Given the difficulty in accurately diagnosing these tumors, and the paucity of data supporting establishment of standard systemic therapy options, management of patients within the setting of a multidisciplinary team, including specialists with expertise in NET, is recommended. Ongoing and future clinical trials hopefully will provide stronger evidence to support treatment recommendations for low- and intermediate-grade lung NET.

Conventional and Nuclear Medicine Imaging in Ectopic Cushing's Syndrome: A Systematic Review

CONTEXT

Ectopic Cushing's Syndrome (ECS) can be a diagnostic challenge with the hormonal source difficult to find. This study analyzes the accuracy of imaging studies in ECS localization.

EVIDENCE ACQUISITION

Systematic review of medical literature for ECS case series providing individual patient data on at least one conventional imaging technique (computed tomography [CT]/magnetic resonance imaging) and one of the following: 111In-pentetreotide (OCT), 131I/123I-metaiodobenzylguanidine, 18Ffluoro-2-deoxyglucose-positron emission tomography (FDG-PET), 18F-fluorodopa-PET (F-DOPA-PET), 68Ga- DOTATATE-PET/CT or 68Ga-DOTATOC-PET/CT scan (68Gallium-SSTR-PET/CT).

EVIDENCE SUMMARY

The analysis comprised 231 patients (females, 50.2%; age, 42.617 y). Overall, 52.4%(121/231) had "overt" ECS,18.6% had "occult" ECS, and 29% had "covert" ECS. Tumors were located in the lung (55.3%), mediastinum-thymus (7.9%), pancreas (8.5%), adrenal glands (6.4%), gastrointestinal tract (5.4%), thyroid (3.7%), and other sites (12.8%), and primary tumors were mostly bronchial neuroendocrine tumors (NETs) (54.8%), pancreatic NETs (8%), mediastinum-thymus NETs (6.9%), gastrointestinal NETs (5.3%), pheochromocytoma (6.4%), neuroblastoma (3.2%), and medullary thyroid carcinoma (3.2%). Tumors were localized byCTin66.2%(137/207), magnetic resonance imaging in 51.5% (53/103), OCT in 48.9% (84/172), FDG-PET in 51.7% (46/89), F-DOPAPET in 57.1% (12/21), 131/123I-metaiodobenzylguanidine in 30.8% (4/13), and 68Gallium-SSTRPET/CT in 81.8% (18/22) of cases. Molecular imaging discovered 79.1% (53/67) of tumors unidentified by conventional radiology, with OCT the most commonly used, revealing the tumor in 64%, followed by FDG-PET in 59.4%. F-DOPA-PET was used in only seven covert cases (sensitivity, 85.7%). Notably, 68Gallium-SSTR-PET/CT had 100% sensitivity among covert cases.

CONCLUSIONS

Nuclear medicine improves the sensitivity of conventional radiology when tumor site identification is problematic. OCT offers a good availability/reliability ratio, and FDG-PET was proven useful. 68Gallium-SSTR-PET/CT use was infrequent, despite offering the highest sensitivity.

Diagnosis and treatment of bronchopulmonary neuroendocrine tumours: State of the art

Bronchopulmonary neuroendocrine tumours (BP-NET) are a heterogeneous population of neoplasms with different pathology, clinical behaviour and prognosis compared to the more common lung cancers. The management of BP-NET patients is largely based on studies with a low level of evidence and extrapolation of data obtained from more common types of neuroendocrine tumours. This review reflects our view of the current state of the art of diagnosis and treatment of patients with BP-NET.