Diagnosis and staging of small intestinal neuroendocrine tumors with CT enterography and PET with Gallium-68: preoperative risk stratification protocol

PURPOSE

Pre-operative diagnosis and staging of small intestine neuroendocrine tumors (SI-NETs) remain sub-optimal, with open palpation during surgery still considered the gold standard. This limits a standardized implementation of minimally invasive surgery (MIS). The aim of this single-center retrospective study was to assess a tailored diagnostic work-up to identify candidates at low risk of undetected disease who may benefit from MIS.

METHODS

Patients diagnosed with SI-NETs between 2013 and 2022 who underwent contrast-enhanced computed tomography enterography (CTE) and Ga68-DOTATOC-positron emission tomography-CT (68 Ga DOTATATE PET/CT) preoperatively and subsequently underwent open surgical resection were included. Imaging studies were reassessed by two radiologists. Combined use of CTE and 68 Ga DOTATATE PET/CT in determining primary lesion disease burden (number of lesions) and LN disease stage (distal and proximal relative to superior mesenteric vessels) was assessed, using surgical reports and pathology as gold standard.

RESULTS

Overall, 56 patients were included. Sensitivity of CTE and 68 Ga DOTATATE PET/CT for at least one primary SI-NET was 100% and 94%, respectively. In the presence of concordance between studies, combined use of CTE and 68 Ga DOTATATE PET/CT for detection of single primary tumors improved specificity to 89% (n = 25/28) with a positive predictive value of 87.5% (n = 21/24). Distal LN disease was identified in 89.2% of cases (n = 33/37). The association of single lesion and distal LN disease was found pre-operatively in 32% of patients (n = 18).

CONCLUSION

Combined use of CTE and 68 Ga DOTATATE PET/CT enables identifying low-risk surgical candidates (single SI-NET lesions with distal LN disease).

Proposal of early CT morphological criteria for response of liver metastases to systemic treatments in gastroenteropancreatic neuroendocrine tumors: Alternatives to RECIST

RECIST 1.1 criteria are commonly used with computed tomography (CT) to evaluate the efficacy of systemic treatments in patients with neuroendocrine tumors (NETs) and liver metastases (LMs), but their relevance is questioned in this setting. We aimed to explore alternative criteria using different numbers of measured LMs and thresholds of size and density variation. We retrospectively studied patients with advanced pancreatic or small intestine NETs with LMs, treated with systemic treatment in the first-and/or second-line, without early progression, in 14 European expert centers. We compared time to treatment failure (TTF) between responders and non-responders according to various criteria defined by 0%, 10%, 20% or 30% decrease in the sum of LM size, and/or by 10%, 15% or 20% decrease in LM density, measured on two, three or five LMs, on baseline (≤1 month before treatment initiation) and first revaluation (≤6 months) contrast-enhanced CT scans. Multivariable Cox proportional hazard models were performed to adjust the association between response criteria and TTF on prognostic factors. We included 129 systemic treatments (long-acting somatostatin analogs 41.9%, chemotherapy 26.4%, targeted therapies 31.8%), administered as first-line (53.5%) or second-line therapies (46.5%) in 91 patients. A decrease ≥10% in the size of three LMs was the response criterion that best predicted prolonged TTF, with significance at multivariable analysis (HR 1.90; 95% CI: 1.06-3.40; p = .03). Conversely, response defined by RECIST 1.1 did not predict prolonged TTF (p = .91), and neither did criteria based on changes in LM density. A ≥10% decrease in size of three LMs could be a more clinically relevant criterion than the current 30% threshold utilized by RECIST 1.1 for the evaluation of treatment efficacy in patients with advanced NETs. Its implementation in clinical trials is mandatory for prospective validation. Criteria based on changes in LM density were not predictive of treatment efficacy. CLINICAL TRIAL REGISTRATION: Registered at CNIL-CERB, Assistance publique hopitaux de Paris as "E-NETNET-L-E-CT" July 2018. No number was assigned. Approved by the Medical Ethics Review Board of University Medical Center Groningen.

Multidimensional characterization of early-stage gastric cancer: Preliminary results of MIMETIC trial

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Background: Gastric adenocarcinoma (GA) represents a leading cause of cancer death worldwide. For localized and locally advanced (LA) GA, accounting for 30% of new diagnoses, surgery, with or without peri-operative chemotherapy (CTX), remains the cornerstone of treatment. Nevertheless, the cure rate remains unsatisfactory. Genomic biomarkers have been tested to tailor anticancer treatments, but no one is able to guide the treatment choice in GA. Gut microbiota represents an emerging area of investigation in cancer, as a key modulator of host immune response. However, its role in GA on treatment tolerability and outcome is not unraveled. Additionally, radiomics, which can perform massive data mining to increase diagnostic power, and extensive dietary assessment are fast-growing tools. Our aim is to set an innovative approach to mapping the interaction among nutrition, microbiome, genomics, and radiomics and correlate them with clinical outcomes. Methods: We are conducting a prospective observational trial in GA patients (pts), candidates to receive peri-operative CTX or upfront surgery. For each patient, we longitudinally collect blood, fecal and salivary samples, alongside clinical and nutritional information. Additionally, past dietary consumption is measured using the food frequency questionnaire. At baseline, CT scan for staging, radiomic analysis, upper digestive endoscopy with biopsy, and molecular biomarkers are performed. Additional samples are taken from tumor and surrounding normal mucosa (1 to 3 cm) for microbiome analysis. Genomic DNA from stool, buccal and gastric tissue samples will be extracted and subjected to 16S metagenomic sequencing. Taxonomic and functional features within and between anatomical compartments will be correlated with clinical and radiomic data. Results: Here, we are presenting preliminary data of fecal samples from 35 GA pts in comparison with a cohort of healthy subjects (HCs) collected at our Institution. Pts’ characteristics are outlined here. We observed that the structure of the gut microbiota of GA pts is distinct from HCs in terms of beta diversity, and this difference is maintained after CTX. In particular, GA’s microbiota was enriched in S. anginosus, among other taxa. Conclusions: Our preliminary data support the feasibility of the study. The differences in structure and composition of the gut microbiota of GA pts compared to HCs confirm previous reports while providing the rationale for developing gut microbiota profiling into a non-invasive biomarker, to implement early diagnosis and prevention. The study is ongoing and actively recruiting.[Table: see text]

Nodal Merkel Cell Carcinoma with Unknown Primary Site and No Distant Metastasis: A Single-Center Series

Simple Summary

Merkel cell carcinoma is a very rare and highly aggressive neuroendocrine carcinoma originating from the skin. Exceptionally it presents with a nodal localization without a cutaneous primary site and distant metastases. This entity is controversial in terms of origin and clinical management. The main histological differential diagnosis is that of small cell neuroendocrine carcinoma. As a referral center for neuroendocrine neoplasms with more than 20 years of experience we have dealt with patients showing this clinical context several times and we usually manage them within our dedicated multidisciplinary team. Due to the extreme rarity of the entity and undefined clinical management, we report our single-center series and detail some of the diagnostic and therapeutic aspects. Our analysis can be helpful for centers which manage these patients and future investigations on the topic.

Abstract

Merkel cell carcinoma (MCC) is a very rare and aggressive neuroendocrine carcinoma originating from Merkel cells, typically with a skin nodule; however, it exceptionally presents with only a basin lymph node localization, with neither a cutaneous primary site nor distant metastases. From 1996 to 2020, among patients with histologically confirmed MCC managed at a neuroendocrine neoplasm-referral center, we selected those with an exclusive nodal basin, no distant metastasis, and an unknown primary site defined by cross-sectional and physical examination. A total of 55 out of 310 patients fulfilled the selection criteria. The median age was 64 years and the majority were males. Inguinal lymph-nodes were the most common anatomic site. With a median follow-up of 4.3 years, the 5-year relapse-free survival (RFS) rate was 56.6 (95% CI 42.0–68.8%) and the 5-year cancer specific survival (CSS) rate was 68.5 (95% CI 52.8–79.9%) for the whole population. The 36 patients (65.5%) undergoing lymphadenectomy (LND) + radiotherapy (RT) ± chemotherapy had a 5-year RFS rate of 87.2% (95% CI 65.5–95.7%) and a 5-year CSS rate of 90.5% (95% CI 67.0–97.5), which were better than those receiving LND alone. In a multivariable analysis, the survival benefit for LND + RT remained significant. Results from one of the largest single-center series of nMCC-UP suggest that a curative approach including RT can be effective, similar to what is observed for stage IIIB MCC. Multicentric studies with homogenous populations should be carried out in this controversial clinical entity, to minimize the risk of biases and provide robust data.

Structured and shared CT radiological report of gastric cancer: a consensus proposal by the Italian Research Group for Gastric Cancer (GIRCG) and the Italian Society of Medical and Interventional Radiology (SIRM)

OBJECTIVES

Written radiological report remains the most important means of communication between radiologist and referring medical/surgical doctor, even though CT reports are frequently just descriptive, unclear, and unstructured. The Italian Society of Medical and Interventional Radiology (SIRM) and the Italian Research Group for Gastric Cancer (GIRCG) promoted a critical shared discussion between 10 skilled radiologists and 10 surgical oncologists, by means of multi-round consensus-building Delphi survey, to develop a structured reporting template for CT of GC patients.

METHODS

Twenty-four items were organized according to the broad categories of a structured report as suggested by the European Society of Radiology (clinical referral, technique, findings, conclusion, and advice) and grouped into three "CT report sections" depending on the diagnostic phase of the radiological assessment for the oncologic patient (staging, restaging, and follow-up).

RESULTS

In the final round, 23 out of 24 items obtained agreement ( ≥ 8) and consensus ( ≤ 2) and 19 out 24 items obtained a good stability (p > 0.05).

CONCLUSIONS

The structured report obtained, shared by surgical and medical oncologists and radiologists, allows an appropriate, clearer, and focused CT report essential to high-quality patient care in GC, avoiding the exclusion of key radiological information useful for multidisciplinary decision-making.

KEY POINTS

• Imaging represents the cornerstone for tailored treatment in GC patients. • CT-structured radiology report in GC patients is useful for multidisciplinary decision making.

Multidisciplinary team approach for Merkel cell carcinoma: the European Institute of Oncology experience with focus on radiotherapy

OBJECTIVE

To review the therapeutic strategy in Merkel cell carcinoma (MCC) treated with radiotherapy (RT) discussed in a multidisciplinary tumour board.

METHODS

Clinical records of patients with a diagnosis of MCC and with an indication to undergo RT at the European Institute of Oncology between 2003 and 2018 were reviewed retrospectively.

RESULTS

Twenty-six patients were included in the analysis (median age 65 years, range 42-87). Nineteen received adjuvant RT, 4 exclusive RT, and the remainder palliative RT. Intensity-modulated RT was used in 13 cases, a 3D conformal technique in 11 cases, and stereotactic RT in 2 cases. No major toxicities were recorded. The median relapse-free survival (RFS) after adjuvant RT was 20.5 months, while for unknown primary MCC, it was 23 months. In the adjuvant setting, median polyomavirus-positive RFS was 21.5 months (range 1-49) and median polyomavirus-negative RFS was only 14 months (range 4-45). Overall, RFS of polyomavirus-positive and polyomavirus-negative patients was 10.5 and 8 months, respectively. After adjuvant RT, only 1 out of 10 patients had a recurrence in the RT field. At the time of data collection, 16 patients were alive with no evidence of disease, 1 patient was alive with advanced status of disease, 8 patients died of disease progression, and 1 patient died of other causes.

CONCLUSIONS

The management of unknown primary and polyomavirus-positive cases, which had a better prognosis in our series, may benefit from a multidisciplinary approach, given the limited data available regarding optimal treatment.

First Ex Vivo Results of β--Radioguided Surgery in Small Intestine Neuroendocrine Tumors with 90Y-DOTATOC

Background: In neuroendocrine tumor (NET), complete surgery could better the prognosis. Radioguided surgery (RGS) with β^--radioisotopes is a novel approach focused on developing a new probe that, detecting electrons and operating with low background, provides a clearer delineation of the lesions with low radiation exposition for surgeons. As a first step to validate this procedure, ex vivo specimens of tumors expressing somatostatin receptors, as small intestine neuroendocrine tumor (SI-NET), were tested. Materials and Methods: SI-NET presents a high uptake of a beta-emitting radiotracer, ⁹⁰Y-DOTATOC. Five SI-NET patients were enrolled after performing a ⁶⁸Ga-DOTATOC positron emission tomography/computed tomography (CT) and a CT enterography; 24 h before surgery, they received 5 mCi of ⁹⁰Y-DOTATOC. Results: Surgery was performed as routine. Tumors and surrounding tissue were sectioned in different samples and examined ex vivo with the beta-detecting probe. All the tumor samples showed high counts of radioactivity that was up to a factor of 18 times higher than the corresponding cutoff value, with a sensitivity of 96% and a specificity of 100%. Conclusions: These first ex vivo RGS tests showed that this probe can discriminate very effectively between tumor and healthy tissues by the administration of low activities of ⁹⁰Y-DOTATOC, allowing more precise surgery.

SARS-CoV-2-related pneumonia can be successfully managed in patients with metastatic neuroendocrine tumors: a critical point of view

Primary neuroendocrine tumors of the thymus are extremely rare. In patients with advanced disease, tumor growth control, and sometimes also syndrome control are the main goals of systemic therapy. Unfortunately, no standard therapies are available in clinical practice; therefore, clinical studies are strongly recommended. Axitinib (AXI) is a tyrosine kinase inhibitor, currently under investigation in an international phase II/III trial including thymic neuroendocrine tumors. Over the past 5 months, the entire world has been facing a devastating medical emergency brought about by a pandemic due to a novel coronavirus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which emerged in Wuhan, China, in late 2019. Since then, health professionals have been expending all their efforts on trying to provide the best available treatments for patients involved. Patients with cancer, especially those with thoracic involvement, are at higher risk of coronavirus disease 19 (COVID-19) and its complications because of their immunosuppressive status caused by the cancer and the anticancer therapies. As it remains unclear how to optimally manage such patients, we wished to report our experience with a patient with a metastatic neuroendocrine tumor of the thymus infected with SARS-CoV-2 in the hope that it may provide some insights and reflections on the management of cancer patients during this challenging time in our history.

18F-FDG PET/CT in asymptomatic patients with COVID-19: the submerged iceberg surfaces

OBJECTIVE

The aim of this case series is to describe our experience in diagnosis and management of oncological asymptomatic patients with COVID-19 who underwent ¹⁸F-FDG PET/CT.

METHODS

From March 9 to March 31, 2020, we identified 5 patients who had PET/CT findings suspicious for COVID-19, but no symptom of infection.

RESULTS

The first three patients were administered an SARS-CoV-2 test in a COVID-dedicated center, while the fourth and fifth were tested in our institution, in accordance with a new internal procedure. The SARS-CoV-2 test yielded positive results in all five patients.

CONCLUSION

In this COVID-19 emergency, our task as radiologists and nuclear medicine physicians is to be able to identify imaging findings suggestive of the disease and to manage patients without overloading the hospital system.

Tumor-non-tumor discrimination by a β- detector for Radio Guided Surgery on ex-vivo neuroendocrine tumors samples

This paper provides a first insight of the potential of the β^- Radio Guided Surgery (β^--RGS) in a complex surgical environment like the abdomen, where multiple sources of background concur to the signal at the tumor site. This case is well reproduced by ex-vivo samples of 90^Y-marked Gastro-Entero-Pancreatic Neuroendocrine Tumors (GEP NET) in the bowel. These specimens indeed include at least three wide independent sources of background associated to three anatomical districts (mesentery, intestine, mucose). The study is based on the analysis of 37 lesions found on 5 samples belonging to 5 different patients. We show that the use of electrons, a short range particle, instead of γ particles, allows to limit counts read on a lesion to the sum of the tumor signal plus the background generated by the sole hosting district.The background on adjacent districts in the same specimen/patient is found to differ up to a factor 4, showing how the specificity and sensitivity of the β^--RGS technique can be fully exploited only upon a correct measurement of the contributing background. This locality has been used to set a site-specific cut-off algorithm to discriminate tumor and healthy tissue with a specificity of 100% and a sensitivity, on this test data sample, close to 100%. Factors influencing the sensitivity are also discussed. One of the specimens set allowed us evaluate the volume of the lesions, thus concluding that the probe was able to detect lesions as small as 0.04 mL in that particular case.

Preoperative evaluation with computed tomography (CT) of the resectability of mesenteric lymph node metastases in small intestine neuroendocrine neoplasms (si-NENs): New criteria for clinicians and surgeons

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Background: The 2016 European Neuroendocrine Tumor Society consensus guidelines update recommends resection of the primary tumor and all mesenteric lymph-nodes for all patients with si-NENs, both with curative and palliative purposes. Current resectability criteria are based on the degree of involvement of the superior mesenteric artery (SMA) by the metastatic lymph nodes. The aim of this work was to test these criteria for the evaluation of our patients; we included as additional criteria the degree of involvement of the superior mesenteric vein (SMV) and peritoneum, two features not covered by current literature. Methods: We retrospectively reviewed the pre-operative CT-scans of all patients with si-NENs operated at IEO (European Institute of Oncology) between 2008 and April 2018. A first analysis classified tumors as “resectable” or “unresectable” according to SMA involvement. A second analysis classified tumors as resectable or unresectable according to SMA involvement, SMV involvement (infiltration of the peripheral or proximal portion) and peritoneal involvement (presence or absence of fibrosis and retraction of the mesentery). We finally reviewed all surgery reports assessing radicality and completeness of the operation. Results: Abdominal CT-scan were available for analysis in 42 out of 47 operated patients. According to the first analysis, all three tumors classified as unresectable underwent incomplete resection, whereas out of the 39 tumors classified as resectable, six received an incomplete resection and 33 were completely resected. According to the second analysis, the nine tumors classified as unresectable underwent an incomplete resection, whereas 33 tumors classified as resectable were completely resected. Conclusions: Our retrospective analysis confirmed that SMA involvement may be useful to evaluate the resectability of the primary tumor and mesenteric lymph nodes. Furthermore, it suggested that the additional evaluation of the SMV and peritoneum involvement can allow to identify further cases of tumors for which complete resection is not possible.

Italian Association of Clinical Endocrinologists (AME) and Italian AACE Chapter Position Statement for Clinical Practice: Assessment of Response to Treatment and Follow-Up in Gastroenteropancreatic Neuroendocrine Neoplasms

Well-established criteria for evaluating the response to treatment and the appropriate followup of individual patients are critical in clinical oncology. The current evidence-based data on these issues in terms of the management of gastroenteropancreatic (GEP) neuroendocrine neoplasms (NEN) are unfortunately limited. This document by the Italian Association of Clinical Endocrinologists (AME) on the criteria for the follow-up of GEP-NEN patients is aimed at providing comprehensive recommendations for everyday clinical practice based on both the best available evidence and the combined opinion of an interdisciplinary panel of experts. The initial risk stratification of patients with NENs should be performed according to the grading, staging and functional status of the neoplasm and the presence of an inherited syndrome. The evaluation of response to the initial treatment, and to the subsequent therapies for disease progression or recurrence, should be based on a cost-effective, risk-effective and timely use of the appropriate diagnostic resources. A multidisciplinary evaluation of the response to the treatment is strongly recommended and, at every step in the follow-up, it is mandatory to assess the disease state and the patient performance status, comorbidities, and recent clinical evolution. Local expertise, available technical resources and the patient preferences should always be evaluated while planning the individual clinical management of GEP-NENs.

The role of multimodal treatment in patients with advanced lung neuroendocrine tumors

Lung neuroendocrine tumors (NETs) comprise typical (TC) and atypical carcinoids (AC). They represent the well differentiated (WD) or low/intermediate grade forms of lung neuroendocrine neoplasms (NENs). Unlike the lung poorly differentiated NENs, that are usually treated with chemotherapy, lung NETs can be managed with several different therapies, making a multidisciplinary interaction a key point. We critically discussed the multimodal clinical management of patients with advanced lung NETs. Provided that no therapeutic algorithm has been validate so far, each clinical case should be discussed within a NEN-dedicated multidisciplinary team. Among the systemic therapies available for metastatic lung NETs everolimus is the only approved drug, on the basis of the results of the phase III RADIANT-4 trial. Another phase III trial, the SPINET, is ongoing comparing lanreotide with placebo. Peptide receptor radionuclide therapy and chemotherapy were not studied within phase III trials for lung NETs, and they have been reported to be active within retrospective or phase II prospective studies. Temozolomide and oxaliplatin are two interesting chemotherapeutic agents in lung NETs. While some European Institutions were certificated as Centers of Excellence for gastroenteropancreatic NENs by the European Neuroendocrine Tumor Society (ENETS), an equivalent ENETS certification for lung NENs does not exist yet. Ideally a lung NEN-dedicated multidisciplinary tumor board should include NEN-dedicated medical oncologists, thoracic medical oncologist, thoracic surgeons, pathologists, interventional radiologists, endocrinologists, radiotherapists, interventional pneumologists, nuclear physician.

Solitary fibrous tumours: unusual aspects of a rare disease

BACKGROUND

In literature there are only a few descriptions of the typical presentation of solitary fibrous tumours (SFT) and only a few case reports showing its unusual clinical and radiological features.

METHODS

We retrospectively evaluated the computed tomography scans of 36 patients presenting with a histological diagnosis of SFT between 1998 and 2008.

RESULTS

We present five cases of SFT with an atypical clinical presentation and radiological features.

CONCLUSIONS

SFT can occasionally present with unusual radiological features making a differential diagnosis difficult. Even thought imaging plays a fundamental role in the initial diagnostic approach, final diagnosis in only confirmed by biopsy and histology.

Assessment of colorectal hepatic metastases by quantitative T2 relaxation time

AIM

To determine the T(2) relaxation time of colorectal hepatic metastases and changes in T(2) relaxation times following chemotherapy.

MATERIALS AND METHODS

42 patients with 96 hepatic colorectal metastases underwent baseline MRI. Axial T(1), T(2) and multi-echo GRASE sequences were acquired. ROIs were drawn on T(2) relaxation maps, obtained from GRASE images, encompassing metastasis and normal liver to record T(2) relaxation time values. In 11 patients with 28 metastases, MRI was repeated using same protocol at 6 weeks following chemotherapy. The median pre-treatment T(2) values of metastases and normal liver were compared using the Mann-Whitney test. The pre- and post-treatment median T(2) values of metastases were compared using the Wilcoxon-Rank test for responding (n=16) and non-responding (n=12) lesions defined by RECIST criteria. The change in T(2) values (ΔT(2)) were compared and correlated with percentage change in lesion size.

RESULTS

There was no difference in the pre-treatment median T(2) of metastases between responding (67.3±8.6) and non-responding metastases (71.4±16.5). At the end of chemotherapy, there was a decrease in the median T(2) of responding lesions (61.6±12.6) p=0.83, and increase in non-responding lesions (76.2±18.4) p=0.03, but these were not significantly different from the pre-treatment values. There was no significant difference in ΔT(2) of responding and non-responding lesions (p=0.18) and no correlation was seen between size change and ΔT(2) (coefficient=0.3).

CONCLUSION

T(2) relaxation time does not appear to predict response of colorectal liver metastasis to chemotherapy.

A possible connective tissue primary lymphoepithelioma-like carcinoma (LELC)

Lymphoepithelial carcinoma is an undifferentiated nasopharyngeal carcinoma with lymphoid stroma and non-keratinizing squamous cells with distinctive clinical, epidemiological and etiological features. Conversely, lymphoepithelioma-like carcinomas (LELCs) are carcinomas that arise outside the nasopharynx but resemble a lymphoepithelioma histologically. In this case study, LELC presentation in connective tissue (left sternocleidomastoid muscle) is peculiar and unusual, but its diagnosis is supported by histological findings and clinical history, especially long disease free survival and no primary lesions in nasopharynx and lung district. We also discuss the pathogenesis, hypothesizing an embryological theory. To our knowledge, it could be the first reported case of a primary connective tissue LELC to the neck.

Screening for lung cancer

The lethality of lung cancer is related to the advanced stage at diagnosis. Initial studies have demonstrated that screening computed tomography (CT) is effective in diagnosing lung cancer at an earlier stage when compared with current clinical practice, however the best clinical approach for screening detected nodules has to be defined. The population to be identified as high risk should be over 50 years of age and should have smoked at least one pack/day for 20 years. CT protocols should use multidetector CT, low dose and a 2.5 reconstruction interval. Diagnostic work-up on detected nodules should be designed according to size and consider CT at 3 or 12 months to evaluate doubling time, CT enhancement, PET/CT and/or FNAB or VATS. The prevalence of lung cancer in the screened population is 1.1%–2.7%, and the incidence is 0.2%–1.1%. Eighty-one percent of cancers are diagnosed in stage I. The percentage of surgery performed for benign lesions ranges from 21% to 55%. In our series, the overall mortality rate was 3.2% in 5 years. The results of randomized clinical studies, when available, will assess the real efficacy of CT in reducing lung cancer related mortality.