Role of PET/PET–CT in the management of sarcomas

Positron emission tomography (PET) is a functional diagnostic imaging technique that provides very different information from that obtainable with other imaging modalities. The most widely used radiotracer is F-18 fluoro-2-deoxy-D-glucose (FDG), which is an analog of glucose. The FDG uptake in cells is directly proportional to glucose metabolism, which is increased many times in malignant cells. FDG-PET is now the standard of care in initial staging, monitoring the response to therapy and management of various cancers (e.g., breast cancer, lung cancer and lymphoma). However, the paucity of anatomical landmarks on PET images makes a consistent hardware fusion to anatomical cross-sectional data extremely useful. The introduction of combined PET–computer tomography (CT) scanners, which provide not only functional, but also structural information leading to a detection of subcentimeter lesions, made this technique useful in the early detection of the disease process and decreasing false-positive lesions. The aim of this article is to review the clinical applications (i.e., diagnosis, staging, evaluation of treatment response and restaging) using PET in patients with bone and soft-tissue sarcoma.     

Role of PET/PET-CT in the management of sarcomas

Positron emission tomography (PET) is a functional diagnostic imaging technique that provides very different information from that obtainable with other imaging modalities. The most widely used radiotracer is F-18 fluoro-2-deoxy-D-glucose (FDG), which is an analog of glucose. The FDG uptake in cells is directly proportional to glucose metabolism, which is increased many times in malignant cells. FDG-PET is now the standard of care in initial staging, monitoring the response to therapy and management of various cancers (e.g., breast cancer, lung cancer and lymphoma). However, the paucity of anatomical landmarks on PET images makes a consistent hardware fusion to anatomical cross-sectional data extremely useful. The introduction of combined PET-computer tomography (CT) scanners, which provide not only functional, but also structural information leading to a detection of subcentimeter lesions, made this technique useful in the early detection of the disease process and decreasing false-positive lesions. The aim of this article is to review the clinical applications (i.e., diagnosis, staging, evaluation of treatment response and restaging) using PET in patients with bone and soft-tissue sarcoma.     

PET/CT supports breast cancer diagnosis and treatment

The application of positron emission tomography with ¹⁸F fluoro-2-deoxy-d-glucose (FDG-PET) has remarkably improved the management of cancer patients. However, some caution is necessary in the interpretation of FDG-PET images. Because of its low spatial resolution, it is difficult to identify the anatomical location of radiotracer uptake and to distinguish between normal physiological accumulation and pathological uptake. A novel combined PET/CT system has been developed that improves the capacity to correctly localize and interpret FDG uptake. Although only a few studies have been conducted on the potential role of PET/CT in the management of breast cancer patients, the advantage of this modality compared with PET alone should be relevant for application in the field of breast cancer. In this review, we describe the clinical impact of PET/CT on breast cancer diagnosis compared with PET alone with respect to disease restaging, treatment monitoring, preoperative staging and primary diagnosis. In addition, the possible role of PET/CT with iodine contrast is noted for evaluation of intra-ductal spreading.     

The prevalence and clinical significance of 18F–2‐fluoro‐2‐deoxy‐D‐glucose (FDG) uptake in the thyroid gland on PET or PET‐CT in patients with lymphoma

F¹⁸–2‐fluoro‐2‐deoxy‐D‐glucose (FDG) positron emission tomography (PET) has become a well established tool in staging and assessing therapy response in lymphoma. Incidental thyroid uptake on PET is not uncommon and can pose a diagnostic and management challenge. We retrospectively evaluate the prevalence and clinical significance of incidental FDG uptake in the thyroid gland in patients with lymphoma. 1868 lymphoma patients underwent PET and PET‐CT between August 2002 and August 2008. 52 patients (2.8%) demonstrated FDG thyroid uptake (M = 17, F = 35; mean age 63 yr). Thyroid uptake was determined as focal or diffuse, maximum standardized uptake values (SUVmax) recorded as well as SUV max ratio compared to background mediastinum activity (SUVR). Corresponding CT findings on PET‐CT were evaluated independently. Results were correlated with clinical, histopathological and imaging follow‐up. 30 (1.6%) patients had focal thyroid uptake. 16 (53%) had histological confirmation either by surgery (n = 7) or FNA under USS (n = 9). The final diagnosis was benign in 12/30 patients and malignant in 9/30. The malignancy risk for focal thyroid uptake was 30%. Five patients had intercurrent thyroid cancer (four papillary, one microinvasive follicular) and four had lymphomatous involvement. There was no significant difference between the mean sizes of benign (23.7 mm, range 12–34) and malignant nodules (23.6 mm, range 8–48). The mean SUVmax of malignant and benign nodules was 4.4 (range 1.8–10.1) and 3.2 (range 1.8–6.9) respectively with no statistically significant difference. 22 (1.2%) patients had diffuse FDG uptake in thyroid and benign aetiology was found in all with adequate follow‐up (15/22). Focal FDG thyroid uptake on PET or PET‐CT in lymphoma patients warrants further investigations. The malignancy risk is 30% either due to intercurrent thyroid cancer or lymphomatous involvement. SUVmax, SUVR and CT attenuation characteristics are not helpful in distinguishing between benign and malignant aetiologies. Diffuse thyroid uptake has a benign aetiology. Copyright © 2010 John Wiley & Sons, Ltd.     

18F-FDG PET/CT对宫颈癌预后的相关研究

因为PET/CT在宫颈癌诊断、分期及指导治疗方面的巨大价值,许多学者开始探索PET/CT在宫颈癌预后方面的价值,尤其是最大标准摄取值(maximum standardized uptake value,SUVmax)在宫颈癌预后方面的作用,研究发现随着治疗前宫颈癌原发病灶或转移淋巴结SUVmax值的升高,患者生存率相应下降,复发率相应升高;并且通过比较宫颈癌原发病灶治疗前后18F-FDG(脱氧葡萄糖)异常浓聚缓解程度来判断预后,完全缓解的患者预后较好,缓解不完全或出现新的18F-FDG异常浓聚的患者预后较差.     

Pancreatic FDG uptake on follow-up PET/CT in patients with cancer

To evaluate the breakdown of unexpected pancreatic ¹⁸F-fluorodeoxyglucose (FDG) uptake and the proportion of secondary primary pancreatic cancer on follow-up, patients with cancer underwent positron emission tomography/computed tomography (PET/CT). The participants consisted of 4,473 consecutive patients with cancer who underwent follow-up PET/CT between January 2015 and March 2019 at Kochi Medical School. Among the participants, 225 with a history of pancreatic cancer were excluded from the present study. Retrospective and blinded PET/CT evaluations of 4,248 patients were performed. In patients with pancreatic FDG uptake, the distribution of FDG uptake in the pancreas was evaluated. The final diagnosis was determined pathologically. A total of 14 (0.3%) of the 4,248 patients exhibited FDG uptake in the pancreatic area. Pancreatic abnormalities were detected in 14 patients, and included five cases of pancreatic metastases (36%), four cases of secondary primary pancreatic cancer (29%), two cases of lymph node metastases (14%), one case of malignant lymphoma (7%), one case of autoimmune pancreatitis (7%) and one case of pseudolesion (7%). One patient with early-stage secondary primary pancreatic cancer had a maximum standardized uptake value (SUV_max) <3.0. The remaining 13 patients had a SUV_max >3.0 in the pancreas. Of the 14 patients, two had multiple foci of FDG uptake in the pancreas. Patients with multiple foci of FDG uptake exhibited pancreatic metastasis from renal cell carcinoma and malignant lymphoma. In conclusion, the majority of patients with unexpected pancreatic FDG uptake on follow-up PET/CT exhibited malignancies; furthermore, ~30% of the malignancies detected in patients with pancreatic FDG uptake were secondary primary pancreatic cancers. In patients with unexpected pancreatic FDG uptake on follow-up PET/CT, primary cancer should be considered as well as metastatic tumors.     

PET evaluation of glucose metabolism in cancer]

Accelerated glycolysis is one of the biochemical characteristics of cancer cells. Based on this fact, positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) has been used in the diagnosis of various cancers. After intravenous injection of FDG and PET scans, most cancers are identified by high FDG accumulation. This metabolic tumor imaging method has been used successfully in the differentiation of benign and malignant tumors, in the diagnosis of metastasis or recurrence, in the detection of primary unknown cancers, and in cancer screening. Because the degree of FDG accumulation reflects tumor glucose consumption, quantification of FDG uptake by PET can be used in predicting biological malignancy and in monitoring treatment in both radiation and chemotherapy. The potential utility of Glut-1 and hexokinase, reported to be responsible for increased glucose metabolism, as biological markers of cancers is yet to be determined.     

Image-guided cancer therapy using PET/CT

Functional imaging with positron emission tomography (PET) is playing an increasingly important role in the diagnosis and staging of malignant disease, image-guided therapy planning, and treatment monitoring. PET scanning with the radiolabeled glucose analogue (18)F-fluorodeoxyglucose ((18)FDG) is a relatively recent addition to the clinically available technology for imaging cancer, complementing the more conventional anatomical imaging modalities of computed tomography (CT) and magnetic resonance (MR). These modalities are complementary in the sense that CT provides accurate localization of organs and lesions while PET maps both normal and abnormal tissue function. When combined, the two modalities can identify and localize functional abnormalities. Attempts to align CT and PET data sets with fusion software are generally successful in the brain, whereas the remainder of the body is more challenging owing to the increased number of possible degrees of freedom between the two scans. Recently these challenges have been addressed by the introduction of the combined PET/CT scanner, a hardware-oriented approach to image fusion. With this device, accurately registered anatomical and functional images can be acquired for each patient in a single scanning session. Currently, over 400 combined PET/CT scanners are installed in medical institutions worldwide, almost all of them for the diagnosis and staging of malignant disease. However, the real impact of this technology undoubtedly will be for cancer therapy, where PET/CT images will be used to guide biopsies and assist in surgical intervention, to define target volumes for radiation therapy and optimize dose, and to monitor response to chemotherapy and establish individualized patient treatment strategies.     

PET/CT对肺内结节诊断及治疗的临床价值

目的 探讨PET／CF显像对肺内结节诊断和治疗的临床应用价值。方法 因肺内结节行^18F-FDG PET／CT检查且得到临床或病理证实的患者20例,其中结节性质不明者15例,临床或病理确诊为肺癌者5例。结合其PET／CT检查结果和临床诊断、治疗资料进行分析。结果 (1)213例PET／CT诊断结果与临床随访或病理诊断结果符合,总诊断符合率100％。15例结节性质不明者经PET／CT检查诊断为良性病变7例,恶性8例．11例CT显示单结节病灶,PET／CT单病灶显影3例,8例除肺内病灶显影外,还可见肺外其他组织显影,6例确诊为有肺外转移,2例肺内单结节病灶系转移灶。(2)PET／CT检查后,20例患者中,16例改变了原治疗方案,继续观察2例,抗炎3例,手术2例,局部放疗4例,单纯化疗3例,综合治疗4例。(3)对8例放射治疗的患者应用PET／CT融合图像指导放疗定位,其中1例MM50适型调强放射治疗1个疗程后1．5个门复查PET／CT,原左侧肺门块状软组织影消失,葡萄糖代谢恢复正常。根据2例手术治疗患者的PET／CT融合图像确定手术路径及切除范围,术后病理结果显示,手术切口边缘及切除淋巴结均未见癌细胞累及和浸润。结论 对于肺内结节性质,PET／CT较单纯CT更容易做出鉴别诊断。PET／CT检查能够更加准确地反映肺癌的临床分期,并辅助临床确定正确的治疗方案。PEW／CT融合图像能够指导放疗生物靶区的精确定位和确定外科手术方案及切除范围。     

18F-FDG PET/CT显像在肝脏恶性肿瘤的初步应用

目的：评价^18F-FDGPET／CT对于肝脏恶性肿瘤的诊断、分期及疗效评判的价值。方法：对55例肝脏恶性肿瘤患者的PET／CT检查资料进行回顾性分析。原发性肝细胞性肝癌（PHC）11例,胆管细胞性肝癌1例,转移性肝癌40例,白血病肝浸润1例,淋巴瘤肝浸润2例。其中原发性肝癌经手术或穿刺证实,继发性肝脏恶性肿瘤均有明确肿瘤病史或临床检查随访证实。所有患者均行双时相全身PET／CT显像检查。结果：低分化PHC4例及胆管细胞癌1例,^18F—FDG异常高摄取,延迟后大部分病灶^18F—FDG摄取SUVmax上升;高分化原发性肝癌7例,其中^18F-FDG等摄取5例,相对肝本底为略低摄取2例;9例PHC及1例胆管细胞癌CT表现为低密度灶,2例PHC为等密度,7例患者有肝炎肝硬化基础,另外同时发现肝外病灶6例。继发性肝脏恶性肿瘤43例（含淋巴瘤、白血病肝浸润）中PET／CT上共发现109个病灶;其中99个肝内病灶表现为^18F-FDG高摄取,31个病灶CT未显示,另外有2例患者有4个病灶经手术证实有肝内微小病灶而PET／CT未检出;而淋巴瘤、白血病肝浸润表现为大片状或弥漫性^18F—FDG明显异常高摄取;大部分患者改变了原有的治疗方案。结论：^18F-FDGPET／CT在肝脏恶性肿瘤诊断、分期、评价分化程度及治疗方案的选择有较好的临床价值,PET／CT诊断肝脏恶性肿瘤明显优于单纯PET。充分认识PET／CT在肝脏恶性肿瘤中的应用价值及局限性,有利于临床对肝脏恶性肿瘤的诊治。     

FDG PET判断鼻咽癌放疗后鼻咽病灶残留的临床价值

背景与目的：18F－2脱氧葡萄糖（FDG）正电子发射计算机断层显像（PET）在判断恶性肿瘤治疗后病灶残留上的应用是放射肿瘤学目前研究的热点之一,本文旨在探讨FDG PET显像在鼻咽癌放射治疗后鼻咽肿瘤残留中的应用。方法：25例鼻咽癌放疗后,临床疑咽肿瘤残留,均行FDG PET显像,显像时间为放疗后2－6个月,其中23例同期行CT检查,最后诊断依靠病理检查和临床随访。结果：25例患者中FDG PET显像阳性18例,其中4例假阳性,阴性7例,其中2例假阴性,FDG PET显像的准确率为76．0％（19／25）,CT检查的准确率为52．2％（12／23）,11例CT未见鼻咽肿瘤残留,FDG PET显示其中2例有鼻咽局部FDG异常浓聚;7例CT诊为肿瘤残留,FDG PET均显示局部病变有FDG异常浓聚,5例CT未能确定残留,PET显示3例FDG异常浓聚,12例FDG异常浓聚的病变处经活检病理证实为肿瘤残留。结论：判断鼻咽癌放疗后鼻咽肿瘤残留,FDG PET比CT有更高的准确性。     

FDG PET/CT在诊断神经系统副肿瘤综合征的研究进展

神经系统副肿瘤综合征（paraneoplastic neurologic syndrome,PNS）是发生于某些恶性肿瘤患者体内神经系统表现异常的一类少见疾病,其临床表现多样,且神经系统症状的出现多早于恶性肿瘤的诊断。虽然抗神经元抗体对诊断PNS有提示作用,但是存在较多假阳性和假阴性情况。因此,PNS的诊断往往是临床工作的难点。PET/CT是一种解剖和功能融合的显像技术,通过一次扫描即可评价全身情况。脱氧氟代葡萄糖（FDG）PET/CT对于PNS的诊断优势不但在于能够显示全身范围内潜在的恶性肿瘤病灶,而且可以早期发现脑部代谢异常。本文通过介绍PNS的发病机制、临床表现、诊断,并对FDG PET/CT在诊断PNS的研究进展做一综述,拟为临床上PNS的诊断提供帮助。      

Positron emission tomography imaging of DMBA/TPA mouse skin multi‐step tumorigenesis

Many tumor cells have elevated rates of glucose uptake that can be measured quantitatively, noninvasively and repeatedly by positron emission tomography (PET) with 2‐deoxy‐2‐[18F]‐fluoro‐D‐glucose (18F‐FDG). Clinical imaging with 18F‐FDG PET has been used for detection and staging of primary and metastatic tumors. High‐resolution microPET scanning and murine cancer models make it possible to analyze longitudinally glucose metabolism during the appearance, development and progression of individual experimental tumors. In this study, we used 18F‐FDG microPET and micro computerized tomography (microCT) to investigate glucose uptake in the DMBA/TPA chemically‐induced multistage mouse skin carcinogenesis model. 18F‐FDG uptake is significantly higher in all papillomas than in surrounding skin. Elevated 18F‐FDG uptake is observed when tumors can be identified morphologically, but not before. Although 18F‐FDG uptake is high in all fully invasive, malignant skin squamous cell carcinomas, uptake in papillomas and microinvasive malignant squamous cell carcinomas is variable and does not exhibit any correlation with tumor stage.     

18F]2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) as a diagnostic tool for neurofibromatosis 1 (NF1) associated malignant peripheral nerve sheath tumours (MPNSTs): a long-term clinical study.

BACKGROUND: Malignant peripheral nerve sheath tumours (MPNSTs) are difficult to detect in neurofibromatosis 1 (NF1) individuals. The purpose was to evaluate [(18)F]2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) and PET computed tomography (CT) as a diagnostic tool for MPNST in NF1 patients with symptomatic plexiform neurofibromas and to verify the diagnosis by pathology and clinical follow-up. PATIENTS AND METHODS: NF1 individuals with symptomatic plexiform neurofibromas underwent clinical evaluation and magnetic resonance imaging. Qualitative FDG PET and PET CT associated with semi-quantitative maximum standard uptake value (SUVmax) assessed possible malignant change. Excision/biopsy verified the diagnosis when possible and clinical follow-up was undertaken in all patients. RESULTS: In all, 116 lesions were detected in 105 patients aged 5-71 years, including 80 plexiform neurofibromas, five atypical neurofibromas, 29 MPNST and two other cancers. Biopsy confirmed the findings in 59 tumours and no MPNST was diagnosed on clinical follow-up of 23 lesions diagnosed as benign on FDG PET and PET CT. FDG PET and PET CT diagnosed NF1-associated tumours with a sensitivity of 0.89 [95% confidence interval (CI) 0.76-0.96] and a specificity of 0.95 (CI 0.88-0.98), but the SUVmax level did not predict tumour grade. CONCLUSION: FDG PET and PET CT is a sensitive and specific diagnostic tool for NF1-associated MPNST. Other PET tracers will be required to solve the problem of predicting tumour grade.     

^18F-FDG PET、PET/CT显像在肝脏占位病变鉴别诊断中的价值

[目的]探讨18F-脱氧葡萄糖（18FDG）PET、PET/CT显像在肝占位病变诊断中的价值。[方法]回顾性分析111例肝占位患者临床资料及PET、PET/CT图像,PET图像计算靶/本比值（T/B）反映代谢活性,T/B〉1为PET诊断恶性标准。[结果]18FFDGPET、PET/CT的诊断灵敏度、特异性和准确率分别为67.0%、58.8%和65.8%。18F-FDGPET、PET/CT对于肝恶性病灶〈1.0cm均未检出,对肝细胞肝癌（HCC）的诊断准确率为54.0%。肿瘤大小、数量和分化程度影响PET对HCC诊断准确率。[结论]PET显像对肝占位性病变鉴别诊断能力差,不适合作为首选诊断方法,病史及其他影像学检查结果可能对提高PET、PET/CT诊断准确率有帮助。     

子宫内膜癌中错配修复蛋白表达缺失的意义

目的:评价MLH1、MSH2、PMS2和MSH6蛋白在子宫内膜癌中的表达缺失率,探讨MMR蛋白在子宫内膜癌发生、发展中的作用。方法:选取87例子宫内膜癌肿瘤组织,应用免疫组化方法检测子宫内膜癌组织中MLH1、MSH2、PMS2和MSH6蛋白的表达。结果:87例子宫内膜癌中MLH1、MSH2、PMS2和MSH6四种蛋白表达缺失率分别为12.6%(11/87)、2.3%(2/87)、16.1%(14/87)、6.9%(6/87),总的蛋白缺失率为31.0%(27/87)。MMR蛋白在不同年龄段的表达缺失率依次为:≤30岁为0%(0/2)、31-40岁为43.8%(7/16)、41-50岁为44.4%(12/27)、>50岁为19.0%(8/42)。I型子宫内膜样腺癌的MMR蛋白缺失率为36.9%,其中高级别的子宫内膜样腺癌中MMR蛋白表达缺失率为58.3%;II型子宫内膜癌中MMR蛋白的表达缺失率为13.6%。MMR蛋白在黏膜内癌、浅肌层浸润癌及深肌层浸润癌中的表达缺失率分别为14.3%(3/21)、29.6%(16/54)、66.7%(8/12),10例淋巴结转移的子宫内膜癌病例中有6例存在MMR蛋白的表达缺失。结论:MMR蛋白在低年龄段、高级别子宫内膜样腺癌、有深肌层浸润及淋巴结转移的子宫内膜癌病例中表达缺失率高,MMR蛋白在子宫内膜癌的进展中具有重要作用,建议临床常规检测子宫内膜癌中MMR蛋白的表达。     

Application of PET and PEt/CT imaging for cancer screening

The aim of this study was to evaluate the potential application of 18-fluorodeoxyglucose positron emission tomography (FDG PET) and PET/CT for cancer screening in asymptomatic individuals. The subjects consisted of 3631 physical check-up examinees (1947 men, 1684 women; mean age +/- SD, 52.1 +/- 8.2 y) with non-specific medical histories. Whole-body FDG PET (or PET/CT), ultrasound and tumor markers were performed on all patients. Focal hypermetabolic areas with intensities equal to or exceeding the level of FDG uptake in the brain were considered abnormal and interpreted as neoplasia. Follow-up periods were longer than one year. Among the 3631 FDG PET (including 1687 PET/CT), ultrasound and tumor markers examinations, malignant tumors were discovered in 47 examinees (1.29%). PET findings were true-positive in 38 of the 47 cancers (80.9%). In addition, 32 of the 47 cancers were screened with the PET/CT scan. PET detected cancer lesions in 28 of the 32 examinees. However, the CT detected cancer lesions in only 15 out of 32 examinees. The sensitivity of FDG PET in the detection of a wide variety of cancers is high. Most cancer can be detected with FDG PET at a resectable stage. CT of the PET/CT for localization and characteristics of the lesion showed an increased specificity of the PET scan. The use of ultrasound and tumor markers may complement the PET scan in cancer screening for hepatic and urologic neoplasms.     

The usefulness of MRI and PET imaging for the detection of parametrial involvement and lymph node metastasis in patients with cervical cancer

OBJECTIVE: The purpose of this study is to elucidate the usefulness of magnetic resonance imaging (MRI) and positron emission tomography (PET) for the detection of parametrial involvement and lymph node metastasis in patients with cervical cancer. METHODS: Thirty-six patients with cervical cancer were retrospectively enrolled. MRI and PET scans were performed for all patients within a week before radical surgery. The criterion for malignancy on MRI was >1 cm short axis diameter of the suspected lymph node. On PET, only fluorodeoxyglucose (FDG) uptake was significantly higher than the background and, if this FDG uptake showed on at least two consecutive axial slices, then the lesion was considered as a malignancy. We compared the extent of tumor on the surgical findings with the FIGO staging, MRI and PET scans. RESULTS: The accuracy of FIGO and MRI staging was 67 and 84.4%, respectively. The accuracy for detecting pelvic lymph node metastasis was better for PET than for MRI (78 versus 67%, respectively). All FDG uptake lymph nodes were confirmed as metastatic lymph nodes by pathological evaluation; this included five lymph nodes <1 cm in diameter. CONCLUSION: MRI provides an improved evaluation of local tumor extension, but PET is more useful for the evaluation of pelvic lymph nodes than MRI; however, PET still misses microscopic disease. Further studies are necessary to evaluate the usefulness of PET/computed tomography (CT) for the accuracy of the disease extension and the cost-effectiveness of MRI, PET or PET/CT in patients with cervical cancer.     

18F‐fluorodeoxyglucose positron emission tomography/computed tomography (FDG‐PET/CT) imaging in the staging and prognosis of inflammatory breast cancer

BACKGROUND:

To prospectively assess fluorodeoxyglucose positron emission tomography/computed tomography (FDG‐PET/CT) staging and prognosis value in patients with suspected inflammatory breast cancer (IBC).

METHODS:

Sixty‐two women (mean age 50.7 ± 11.4 years) presenting with unilateral inflammatory breast tumors (59 invasive carcinomas; 3 mastitis) underwent a PET/CT scan before biopsy.

RESULTS:

PET/CT scan was positive for the primary malignant tumor in 100% and false positive in 2 of 3 benign mastitis. In 59 IBC patients, FDG nodal foci were detected in axillary (90%; n = 53) and extra‐axillary areas (56%; n = 33) ipsilateral to the cancer. Compared with clinical examination, the axillary lymph node status by PET/CT was upstaged and downstaged in 35 and 5 patients, respectively. In 7 of 9 N0 patients, the axillary lymph node positivity on PET/CT was correct, as revealed by pathological postsurgery assessment (not available in the 2 remaining patients). The nodal foci were compared with preoperative fine needle aspiration and/or pathological postchemotherapy findings available in 44 patients and corresponded to 38 true positive, 4 false‐negative, and 2 false‐positive cases. In 18 of 59 IBC patients (31%), distant lesions were found. On the basis of a univariate analysis of the first enrolled patients (n = 42), among 28 patients who showed intense tumoral uptake (standard uptake value_max>5), the 11 patients with distant lesions had a worse prognosis than the 17 patients without distant lesions (P = .04).

CONCLUSIONS:

FDG‐PET/CT imaging provides additional invaluable information regarding nodal status or distant metastases in IBC patients and should be considered in the initial staging. It seems also that some prognostic information can be derived from FDG uptake characteristics. Cancer 2009. © 2009 American Cancer Society.     

FDG-PET/CT and parathyroid carcinoma: Review of literature and illustrative case series

Parathyroid cancer is an uncommon malignant cancer and is associated with a poor prognosis. The staging of parathyroid cancer represents an important issue both at initial diagnosis and after surgery and medical treatment. The role of positron emission tomography/computed tomography (PET/CT) with 18F-Fluorodeoxyglucose (18F-FDG) as an imaging tool in parathyroid cancer is not clearly reported in the literature, although its impact in other cancers is well-defined. The aim of the following illustrative clinical cases is to highlight the impact of PET/CT in the management of different phases of parathyroid cancer. We describe five patients with parathyroid malignant lesions, who underwent FDG PET/CT at initial staging, restaging and post-surgery evaluation. In each patient we report the value of PET/CT comparing its findings with other common imaging modalities (e.g., CT, planar scintigraphy with 99mTc-sestamibi, magnetic resonance imaging) thus determining the complementary benefit of FDG PET/CT in parathyroid carcinoma. We hope to provide an insight into the potential role of PET/CT in assessing the extent of disease and response to treatment which are the general principles used to correctly evaluate disease status.