TEP/TDM dans le diagnostic et la stadification des lymphomes

Histological subtypes of lymphomas are important because FDG uptake is much greater in aggressive than in indolent lymphomas and this, results in lower sensitivity of PET for the staging of indolent lymphomas. Staging is especially useful when treatment is changed according to staging. Staging with imaging methods has traditionally been performed using a CT scanner and has been based on the detection of nodal enlargement, an increased number of small nodes and in the presence of extranodal masses. However, CT is limited by its poor sensitivity in the detection of extranodal sites of involvement, in the identification of tumour involvement of normal size lymph nodes and in the differentiation between malignant and inflammatory enlarged lymph nodes. The uptake of FDG detected with PET images reflects metabolic activity rather than the size of the tissue masses, localizing tumoral activity in enlarged and in normal size lymph nodes. In the literature review that compares PET with CT, PET usually indicates more lesions than CT would and PET improves sensitivity without losing specificity. However, the majority of studies report that PET, improves the staging in a relatively limited number of patients (10-20%) and may change treatment in less than 10% of patients. Diagnostic accuracy of PET may improve with the use of hybrid PET/CT systems that combine metabolic and morphological imaging, in the same scanner and without moving the patient. This is a promising technique that will overcome the limitations of both modalities and may enhance diagnostic accuracy in lymphoma patients. This hybrid equipment allows the use of PET/CT with contrast-enhanced full dose CT (a diagnostic CT) instead of carrying out PET and CT on different days.     

TEP/TDM au FDG et bilan initial des lymphomes : du diagnostic au pronostic

Lymphoma represents a very heterogeneous pathologic disease group and its initial assessment, treatment strategy and prognosis is closely related within each histological subtype. The diagnosis of lymphoma disease is often due to the development of a tumour mass at a lymph node area, or within an organ with or without systemic symptoms. However, all these signs remain non specific. Biopsy is the only reliable diagnostic tool, which can be carried out surgically or guided by the morphological and functional imaging. Once the histological diagnosis is determined by the WHO classification, the staging procedure aim is to provide the prognosis to assist the therapeutic decision. Morphologic imaging primarily based on CT remains the reference in exploring most cases. But in the last decade, the introduction of functional imaging using FDG-PET/CT has dramatically changed the therapeutic management of lymphoma. The additional clinical value provided by initial FDG-PET/CT could lead to an alteration of the therapeutic strategy, as well as to the optimization of radiation therapy or to the establishment of prognostic score and lead to improved lymphoma patient survival in the future.     

增强CT和18F-FDG PET/CT在胃癌术前分期评估中的临床价值比较

目的:对比评估增强计算机断层扫描(contrast enhancement computed tomography,CECT)和~(18)F-FDG正电子发射计算机断层扫描(positron emission tomography/computed tomography,PET/CT)在胃癌术前分期中的临床应用价值。方法:回顾性分析经病理证实的胃癌患者的术前CECT(27例)及~(18)F-FDG PET/CT(39例)图像,于两种影像学手段下,双盲法判定每位患者胃癌的TNM分期,然后分别计算每种影像学方法在胃癌术前分期中的敏感性、特异性、阳性预测值、阴性预测值和准确性。两种影像学方法的差异比较采用Pearson卡方检验。结果:CECT和~(18)F-FDG PET/CT诊断胃癌T分期的敏感性、阳性预测值和准确性分别是100.00%、72.73%、59.26%和100.00%、90.91%、76.92%;CECT和~(18)F-FDG PET/CT诊断胃癌N分期的敏感性、特异性、阳性预测值、阴性预测值和准确性分别是75.00%、71.43%、88.24%、50.00%、74.07%和42.86%、92.00%、75.00%、74.19%、35.90%。结论:CECT和~(18)F-FDG PET/CT均可用于胃癌术前分期的预估,尤其在N分期方面,CECT的敏感性和准确性高于~(18)F-FDG PET/CT。     

Intérêt de la TEP/TDM au 18FDG dans les sous-types histologiques agressifs de cancers thyroïdiens (oncocytaire et peu différencié)

IntroductionThe objective of our study was to evaluate the performance of ¹⁸FDG PET/CT in aggressive histological subtypes of differentiated cancer of the thyroid and its therapeutic impact.MethodThirty-three patients (22 Hürthle cell carcinoma and 11 poorly differentiated carcinoma) who underwent FDG PET/CT were retrospectively included. Nine scans have been performed for initial staging, 16 for suspicion of recurrence (with 11 having a rising Tg), 3 for the reassessment of metastatic disease under systemic treatment and 30 systematically during follow-up. The results of PET/CT were confronted with histological data and follow-up results.ResultsThirteen out of 18 positive scans were confirmed (8 locoregional recurrences and 5 distant metastases). The majority of them were performed for a suspicion of recurrence (8) or for initial staging (2). The sensitivity, specificity, PPV, and NPV were respectively 81.2%, 88.1%, 72.2% and 92.5%. For Hürthle cell carcinoma and poorly differentiated carcinoma, the sensitivity and specificity were respectively 100% vs. 57% and 86% vs. 93%. Systematic PET scans were most of the time negative (26/30) and in accordance with histological and follow-up results. It was the same in case of scans performed for undetectable initial Tg (16/22). PET/CT modified patient management in 14% of the cases.ConclusionThis study confirms the good performances of ¹⁸FDG PET/CT for initial staging and in case of elevated Tg during the follow-up of aggressive histological subtypes of thyroid cancer. It does not seem relevant in the absence of a suspicion of recurrence or in the case of undetectable initial Tg.     

Role of PET/CT in diagnosis and treatment of breast cancer -- review of present knowledge and perspectives for future research

Positron emission tomography (PET) has revolutionized the diagnostic opportunities of malignances, however, it has still a controversial role at some conditions in the management of breast cancer. The article compares PET alone and PET/CT. We review the latest trends of using PET or PET/CT for diagnosis, staging, evaluation of the primary tumor and regional lymph node status, as well as early detection of recurrence and distant lesions. PET/CT provides new methods of assessment of early chemo/endocrine therapy response of locally advanced breast cancer. We discuss the development of new radiotracers and their value in predicting treatment response, identifying tumor subtypes and finding new therapeutic targets by them.     

CT及MRI在直肠癌诊断和分期的应用价值研究

目的:探究在直肠癌的诊断以及分期方面,CT与MRI技术的应用价值。方法:选取我院近年来经过病理检测,确诊为直肠癌的患者160例,随机分为两个实验组,其中一组采取CT成像方法,另一组患者采取MRI成像。并记录在不同的分期中CT及MRI的应用价值。CT诊断包含了常规CT平扫以及CT增强扫描,MRI诊断包括轴位DWI、T2W1冠状位以及矢状位、轴位T1WI、轴位T2WI的图像。结果:在直肠癌的诊断中,CT诊断的T分期与病理性T分期差异不大,其准确率为70.0%。MRI诊断的T分期和病理性T分期差异极小,其准确率为85.0%。CT诊断的N分期与病理性N分期差异不大,准确率为72.5%;MRI诊断的N分期与病理性N分期差异较小,其准确率为87.5%。CT诊断的T分期以及N分期的准确率与MRI诊断的T分期以及N分期的准确率之间差异均存在统计学意义(P0.05)。结论:在直肠癌的术前诊断以及局部分期中,MRI诊断与CT诊断相比,有更高的诊断价值。     

Cancer de la prostate : utilité de la TEP-TDM à la F-fluorocholine

In oncology, positron emission computed tomography (PET/CT) has become an essential tool for initial staging, response evaluation and follow-up of cancer patients. Most of the frequent tumors (lung, breast, esophagus, and lymphomas) are highly avid for ¹⁸F-fluorodeoxyglucose (¹⁸FDG), but prostate cancer has not demonstrated significant uptake of FDG. The development of new tracers labeled with ¹⁸F such as choline analogs allowed already to obtain interesting results particularly in patients with biological relapse and inconclusive conventional imaging work-up. The impact of ¹⁸F-flurocholine PET/CT on patient management needs to be validated in large studies, but many centers use already this examination in order to guide further management, including radiotherapy planning.     

Tomographie par émission de positons et cancer de la prostate

Positron emission tomography (PET) is a major imaging modality in oncology. Fluorodeoxyglucose (FDG) PET is of limited usefulness in prostate cancer, be it for initial staging or for detection of recurrence. New PET tracers could improve PET performances in prostate cancer staging and when recurrence is suspected. Lipid metabolism tracers, such as choline and fluorine-18-labelled choline analogues, seem to be promising in these indications. The impact of these PET examinations on patient management should be further evaluated, taking into consideration the new therapeutic strategies, in particular salvage local treatment in case of isolated local recurrence.     

La TEP/TDM au FDG a-t-elle un impact dans la prise en charge des patients atteints d’un cancer du canal anal ?

PurposeTo evaluate the impact of FDG PET/CT on the management of patients referred for the staging and/or the follow-up of anal carcinoma, and PET/CT on patient management.Patients and methodsWe included patients referred to our department for anal carcinoma whose therapeutic management was evaluable thanks to follow-up data during at least 6 months.ResultsData of 44 patients were analysed: 22 had PET/CT for initial staging and 36 during follow-up. PET/CT had impact in nine patients out of 44 (20%) and it was relevant in eight of them.ConclusionFDG PET/CT is an accurate imaging modality in anal cancer, its impact on patient management is more obvious when persistence or recurrence of disease is suspected.     

Role of the CT scanner in the management of cancer.

Although the diagnostic scope of computed tomography has widened considerably in recent years, assessment of patients with suspected or known malignant disease remains the major reason for body CT referrals in the United Kingdom. This paper sets out to define important advantages and limitations of CT in cancer diagnosis, addressing the topics of primary diagnosis, staging, and patient follow up. There is relatively little information on the influence of CT on patient management in oncology but reported studies indicate that CT directly alters clinical decisions in 14-30% of patients. This aspect requires further evaluation and is of particular relevance when considering the appropriate use of high cost technology.     

Role and Cost Effectiveness of PET/CT in Management of Patients with Cancer

PET/CT is a relatively new imaging technology, whose undoubted advantages are valuable in clinical oncology as well as in all fields of diagnosis, staging, and treatment. The hardware combination of anatomy and function has been the true evolution in imaging. PET using 18F-fluorodeoxyglucose (FDG) is increasingly used for the staging of solid malignancies, including colon, lung, etc., but anatomic information is limited. Integrated PET/CT enables optimal anatomic delineation of PET findings and identification of FDG-negative lesions on computed tomography (CT) images and might improve preoperative staging. However, controversy still exists in relation to the application of PET/CT in clinical practice, mainly because of its high cost. It is evident that apart from additional costs, potential savings also are associated with PET/CT as a result of avoiding additional imaging examinations or invasive procedures and by helping clinicians make the optimum treatment decisions. The authors review the literature on the role of PET/CT in management of various tumors and discuss the medicoeconomic usefulness.     

Le cancer de la prostate: Acquis et challenges pour l'an 2000

Principles of the diagnosis and treatment of prostate cancer at any stage are still improving. Early diagnosis is accessible throughout the use of the PSA test associated with digital rectal examination which lead to indicate transrectal biopsies. This allowed to treat patients at an earlier stage and significantly improved prognosis in the case of organ confined disease. Progress made in the radical prostatectomy technique have contributed to decrease the postoperative morbidity and is the treatment of reference in clinically localized disease. Radiation therapy still remains a valuable alternative, however, results are more difficult to evaluate. Hormonal treatment using androgen deprivation is indicated at the stage of metastasis. LHRH agonist associated with anti antiandrogens are as much efficacious as surgical castration. Unfortunately, the prognosis of advanced disease remains unpredictable. Objectives for the future will be to improve the diagnostic and staging of prostate cancer et to better define therapeutic indications; better understand the effects of androgen deprivation; and to propose new therapies for hormone refractory cancers.     

La fluorocholine(18F) a une utilité clinique dans le cancer de la prostate et le carcinome hépatocellulaire… parfois chez le même malade

Case reportIn order to stage hepatocellular carcinoma (HCC), a patient was referred to PET/CT using fluorodeoxyglucose(18F) (FDG) and, if necessary, fluorocholine(18F) (FCH). HCC was proven by biopsy of a hepatic mass discovered on CT performed for a biological recurrence of prostate cancer.ResultFDG PET/CT did not show any anomaly. FCH PET/CT was thus performed and showed various foci: the hepatic mass, a large abdominal adenopathy and an unexpected subcentimetre lung nodule. The diagnostic uncertainty mostly concerned this lung nodule which was biopsied and consisted of a metastasis of the prostate cancer. Due to the presence of two metastatic cancers, the patient's management was altered, with chemotherapy for the HCC and hormone therapy for the prostate cancer.ConclusionSeveral types of cancer take-up fluorocholine(18F), which is a powerful tool to detect metastases, in particular in case of rising levels of marker with a negative FDG PET/CT. Even when FDG PET/CT is positive, FCH may reveal unexpected foci with other metabolic characteristics, although it is not specific of a given primary cancer, as well as FDG. For staging of HCC, we thus recommend to perform PET/CT with both tracers.     

Tomographie à émission de positons et lymphomes

There is an abundant literature dealing with FDG PET imaging in lymphomas and Hodgkin's disease. Several meta-analysis are available, along with international recommendations. In this concise review, we will discuss the major indications of the technique. FDG PET/CT imaging should be performed as part of the initial staging of Hodgkin's disease and potentially curable non-Hodgkin's lymphomas, and possibly for the follicular lymphomas as well. Although the clinical impact at initial diagnosis is fairly limited, the initial metabolic picture will be of great value for assessing the response to treatment. Indeed, FDG PET/CT has become the cornerstone for evaluating the disease status after completion of treatment. Although a negative PET study has a very high predictive value and does not need any further confirmation, a positive PET study cannot be relied upon solely to modify the treatment and a confirmatory biopsy should be performed whenever possible. Furthermore, the predictive value of an interim PET study, performed early on during treatment i.e. after two or three courses of chemotherapy, appears very high, probably higher than when the PET is performed after treatment. However, the available data are not sufficient to support altering the treatment scheme depending on the PET results only. Several large studies are nevertheless under way, which should provide further clarifications in the near future.     

TEP au 18-FDG et cancers ORL : récidive et surveillance post-thérapeutique

Recurrence of head and neck squamous cell carcinomas occurs early and currently, with poor prognosis. Post-therapeutic surveillance aims to diagnose a recurrence as early as possible in order to perform curative salvage therapy. The risk of recurrence is highest in locally advanced cancers. Morphological imaging, including Computed Tomography (CT Scan) and magnetic resonance imaging, can be limited by the anatomic changes following surgery and radiotherapy, and sometimes cannot provide early diagnosis of recurrence. Histology presents some risk of morbidity, especially in irradiated tissues, and sampling error. Positron Emission Tomography (PET) with 18F-fluorodeoxyglucose (FDG) is superior to conventional imaging for the diagnosis and staging of recurrence, especially when it is performed three months after the end of treatments. FDG-PET has high sensitivity and negative predictive value for recurrence, so that further morphological and invasive investigations should not be performed in case of negative examination. On the other hand, because of its limited specificity and positive predictive value, any positive PET finding should be documented, in order to avoid false positives findings. The diagnosis of recurrence is the field of application in which FDP-PET has the greatest impact on head and neck cancer management: it is considered as a standard. However, the interest of FDG-PET during systematic follow-up has not yet been confirmed. PET should only be performed in difficult cases and within evaluation protocols.     

X线片和多层螺旋CT诊断及鉴别周围型肺癌的对比研究

目的:对比X线平片和多层螺旋CT诊断及鉴别周围型肺癌的效果。方法:选取了100例周围型肺癌患者,所有患者入院后先行X线片检查,后进行多层螺旋CT检查。通过观察并记录X线片与多层螺旋CT对周围型肺癌的影像学特征、临床TNM分期的诊断效果,评价X线平片和多层螺旋CT对周围型肺癌的诊断效果。结果:多层螺旋CT对周围型肺癌的肿块、分叶征、支气管气象征、空洞、胸膜凹陷、血管集束征,胸腔积液的检出率均高于X线片(P0.05)。根据外科病理TNM分期结果,多层螺旋CT对周围型肺癌的临床TNM分期诊断符合率为92.0%,X线对周围型肺癌的临床TNM分期诊断符合率为61.0%,多层螺旋CT对周围型肺癌的临床TNM分期诊断符合率明显高于X线(P0.05)。结论:多层螺旋CT对于周围型肺癌各类型影像学征象具有较好的检出率,对周围型肺癌临床TNM分期诊断准确性接近病理诊断结果。     

MRI与CT检查对卵巢癌病理分期及复发转移的诊断价值对比研究

摘要 目的：对比磁共振成像（MRI）与计算机断层扫描（CT）检查对卵巢癌病理分期及复发转移的诊断价值。方法：纳入2017年1月～2019年1月于我院接受诊治的卵巢癌患者100例进行研究。所有患者术前均进行MRI与CT检查,并以术后病理组织活检结果为金标准,对比MRI与CT诊断卵巢癌与卵巢癌病理分期的准确率。所有患者均于首次检查6个月后进行复诊,对比MRI与CT诊断卵巢癌复发转移的准确率。结果：MRI诊断卵巢癌的确诊率为94.00%（94/100）,高于CT诊断的81.00%（81/100）;漏诊率为2.00%（2/100）,低于CT诊断的10.00%（10/100）（均P＜0.05）。MRI诊断卵巢癌Ⅰ期、Ⅱ期、Ⅲ期的准确率分别为93.33%（14/15）、95.00%（19/20）、93.33%（28/30）,高于CT诊断的60.00%（9/15）、65.00%（13/20）、73.33%（22/30）（均P＜0.05）。MRI诊断肠管及周围、盆腔淋巴结、腹膜后淋巴结、肝脏等远处侵袭和转移中的准确率分别为100.00%（26/26）、88.89%（24/27）、75.00%（18/24）、95.00%（19/20）,高于CT诊断的76.92%（20/26）、48.15%（13/27）、41.67%（10/24）、45.00%（9/20）（均P＜0.05）。结论：相较于CT检查,MRI检查诊断卵巢癌的准确率更高,漏诊率更低,且在卵巢癌病理分期以及复发转移的诊断准确率更高,具有较好的临床应用价值。     

The role of endoscopic ultrasound in the evaluation of rectal cancer

Accurate staging of rectal cancer is essential for selecting patients who can undergo sphincter-preserving surgery. It may also identify patients who could benefit from neoadjuvant therapy. Clinical staging is usually accomplished using a combination of physical examination, CT scanning, MRI and endoscopic ultrasound (EUS). Transrectal EUS is increasingly being used for locoregional staging of rectal cancer. The accuracy of EUS for the T staging of rectal carcinoma ranges from 80-95% compared with CT (65-75%) and MR imaging (75-85%). In comparison to CT, EUS can potentially upstage patients, making them eligible for neoadjuvant treatment. The accuracy to determine metastatic nodal involvement by EUS is approximately 70-75% compared with CT (55-65%) and MR imaging (60-70%). EUS guided FNA may be beneficial in patients who appear to have early T stage disease and suspicious peri-iliac lymphadenopathy to exclude metastatic disease.     

Apport de la TEP/TDM dans les cancers broncho-pulmonaires : étude d’une série de 35 cas

Lung cancer is one of the most common cancers in Morocco. Currently, PET/CT with FDG is described as the best suited imaging test to evaluate the initial extension of this type of cancer in it non-metastatic variety. Our study confirms the literature data, showing the superiority of PET/CT versus CT in the initial staging of lung non-small cell carcinoma.     

Isolated skeletal muscle metastasis following successful treatment of laryngeal cancer: case report

Skeletal muscle metastases from tumors are a rare occurrence and can present difficult management decisions. We report here on a patient that had been previously treated for squamous cell laryngeal cancer with surgical resection and adjuvant systemic chemotherapy that presented with a metastasis to the rectus abdominis muscle without evidence of recurrent disease at the primary site. After a metastatic workup with PET/CT scan suggested this to be an isolated lesion, surgical excision with negative margins was performed based upon limited treatment options secondary to the location of the tumor and his favorable prognosis suggested by his pathological staging at the time of the initial resection. Here we discuss the incidence of distant metastases from laryngeal cancer and appropriate screening methods. Additionally, skeletal muscle metastases and treatment considerations are discussed.