CT定位经皮穿刺缓释化疗粒子联合~(125)I粒子植入治疗晚期恶性肿瘤的价值

目的:探讨CT引导经皮穿刺缓释化疗粒子联合125I粒子植入在治疗晚期恶性肿瘤中的价值。方法:共37例晚期肺癌、肝癌、胰腺癌、鼻咽癌及直肠癌术后复发患者,根据术前CT或MRI检查所见肿瘤大小、形态,应用肿瘤治疗计划系统制定125I粒子和缓释化疗粒子治疗计划,并确定穿刺途径,在CT定位引导下植入缓释化疗粒子和125I粒子,在术后第1、3、6、12个月进行CT随访检查,对肿瘤的大小、密度进行评估。结果:术后随访,肿瘤体积缩小,密度降低,病灶无或轻度强化;无严重并发症。术后第6个月时有效率83.78%,生存率为100%;术后第12个月有效率为70.27%,生存率为78.38%。结论:CT定位经皮穿刺缓释化疗粒子联合125I粒子植入在晚期恶性肿瘤治疗中具有方便、安全、疗效高的特点,对治疗晚期肿瘤有着重要的价值。     

TACE联合CT导向下125I放射性粒子植入治疗肝癌

目的探讨经皮导管动脉化疗栓塞术（TACE）联合CT导向下^125I放射性粒子植入治疗肝癌的方法。方法16例接受过碘油柃塞治疗的患者术前均行CT扫描,根据扫描结果制订术前计划,确定放射性粒子植入数量及位置,勾画肿瘤靶区时应超出碘油沉积范围0．5～1．0cm,^125I粒子平均能量27～35keV。结果27例患者中完全缓解2例,部分缓解16例,无变化6例,进展3例,总有效率66．7％。术后6个月随访,除1例死于远处转移外,其余患者均生存。结论TACE联合CT导向下^125I碘放射性粒子植入是治疗肝癌的安全有效的方法。     

CT引导下125Ⅰ粒子植入治疗难治性盆腔恶性肿瘤

目的评价CT引导下^125I粒子组织间植入治疗盆腔难治性恶性肿瘤的临床疗效，探讨粒子植入技术。方法23例盆腔恶性肿瘤，均为术后复发接受化疗和（或）根治量放疗肿瘤仍进展患者，瘤体最大径3.5—7．0cm，平均4．5cm。粒子植入术前1～3d行模拟CT扫描，采用治疗计划系统（TPS）制定粒子植入计划，根据处方剂量求出术中所需^125I粒子的总活度并算出治疗粒子数量。在CT引导下经皮穿刺植入^125I粒子。其中6例患者粒子植入前或后接受髂内动脉灌注化疗。结果单个瘤体内首次植入粒子数为9～75粒，平均27粒。6例接受髂内动脉灌注化疗共14个疗程。粒子植入术后72h～4周，下肢疼痛和（或）肛门、会阴周围疼痛坠胀不适，完全缓解5例，部分缓解11例，有效率69．6％（16／23）。术后随访2～34个月，中位随访21个月，部分缓解（PR）18例；无变化（SD）4例；进展（PD）1例，总有效率78．3％（18／23）。死亡3例，存活20例，最长生存时间34个月。结论CT引导下^125I粒子植入对盆腔难治性恶性肿瘤安全、有效。     

CT导向下125I粒子植入联合髂内动脉化疗灌注治疗盆腔复发肿瘤

目的探讨CT导向下125I粒子植入联合髂内动脉化疗灌注治疗盆腔肿瘤复发的临床疗效.方法总结8例盆腔复发肿瘤采用CT导向下125I放射性粒子植入联合髂内动脉化疗灌注患者的疗效.所有患者术前或术后给髂内动脉灌注化疗,化疗方案根据原发肿瘤的类型确定.粒子植入之前采用TPS模拟布源或遵循Halarism的125I经验公式mCi=Da×5,Da为靶组织长、宽、高的平均值(L+W+H)/3,单位为cm,求出术中所需125I粒子的总活度及算出治疗粒子的数量.在螺旋CT导向下将125I放射性粒子植入盆腔肿瘤内.结果全组8例患者8个病灶2个月后采用PET-CT评价,完全缓解(CR)0例,部分缓解(PR)5例,稳定(NC)2例,进展(PD)1例,全组病例随访1年,死亡2例,其余6例存活,最长的生存时间15个月.结论125I放射性粒子植入联合髂内动脉灌注化疗是治疗盆腔肿瘤复发的一种有效的方法.     

CT引导下125I粒子植入治疗复发性直肠癌的临床应用

目的探讨CT引导下^125I放射性粒子植入治疗胰腺癌技术的可行性和疗效。方法对40例不能手术切除的晚期胰腺癌患者作CT引导下植入^125I粒子治疗。术前采用治疗计划系统（TPS）重建胰腺肿瘤的三维立体图像,计算出植入的^125I粒子数目、空间分布和剂量分布率,在CT引导下将^125I粒子植入胰腺肿瘤内,采用^125I粒子活度为0．5～0．8mCi／颗,相隔1．0cm植入,避开血管和胰管等周围要脏器。放射性粒子的肿瘤匹配周边剂量（matched peripheral dose,MPD）为60～140Gy。中位植入粒子36颗（18～68颗）,术后即刻行CT扫描进行粒子质量验证。术后1周10例患者给予吉西他滨和5-Fu动脉灌注化疗,3～4个疗程。结果全组肿瘤平均直径为4．9cm。治疗后随访2～28个月,术后患者顽固性疼痛症状明显缓解（P〈0．05）,Karnofsky评分显著提高（P〈0．05）。平均术后2～5d疼痛开始缓解。术后2个月CT随访,肿瘤完全缓解（CR）3例,部分缓解（PR）20例,无变化（NC）14例,进展（PD）3例。总有效率（CR＋PR）为57．5％。全组中位生存时间为10．2个月。Ⅱ、Ⅲ、Ⅳ期粒了植入术后中位生存期分别为14．7、10．9及7．1个月;6个月和12个月累计生存率分别为100％、88％、62％和70％、41％、0。其中5例合并肝转移患者,则同时行动脉栓塞治疗。3例患者术后随访发现4颗粒了迁移到肝脏内。住随访过程中未见上消化道出血、胰腺炎、胰瘘及放射十牛肠炎等并发症。结论CT引导下植入^125I放射性粒子治疗胰腺癌,近期疗效确切,具有良好的止痛效果,是一种安全、有效、并发症发生率低的微创治疗方法,粒了治疗后联合化疗药物动脉灌注治疗,有望提高疗效,远期疗效尚待进一步随访和观察。     

CT导向下125I粒子组织间植入治疗非小细胞肺癌

目的探讨CT引导下经皮穿刺植入^125I粒子近距离内照射治疗晚期非小细胞肺癌（NSCLC）的方法、疗效及并发症的处理。方法选择21例术前活检证实为NSCLC的患者,根据治疗计划系统（TPS）计算布源,于CT引导下经皮穿刺植入^125I粒子。粒子活度0．5～0．8mCi,间隔1．0～1．5cm多层面植入肿瘤内。术后即刻CT扫描验证,2～6个月复查CT观察粒子在瘤体内的分布、疗效及有无并发症,随访12个月。结果随诊CT复查,21例患者中完全缓解7例;部分缓解12例;稳定（无变化）2例。1年生存率90．5％（19／21）。并发症包括术中气胸6例,咳血2例。未见严重并发疗和治疗相关的放射损伤。结论CT导向下^125I粒了植入治疗NSCLC安全、有效,近期疗效肯定。     

CT导向下^125I粒子组织间插植治疗恶性肿瘤的临床应用

目的：介绍CT导向下^125I粒子组织间插植治疗恶性肿瘤的技术方法并评价其临床价值。方法：17例36个恶性肿瘤病灶，在CT引导下进行肿瘤内^125I粒子组织间插植。首先根据影像资料，利用TPS计算出治疗肿瘤所需要^125I粒子的最佳数量及分布，然后在CT导向下经皮穿刺将^125I粒子植入到肿瘤内，术后2月随访。结果：CR17个（47．2％），PR11个（30．6％），NC4个（11．1％），PD1个（2．8％）。结论：CT导向下组织间植入^125I粒子治疗恶性肿瘤是一种安全、可靠、疗效显著的治疗方法。     

125I放射性粒子植入联合栓塞化疗治疗肾上腺转移瘤临床应用

目的 探讨CT导引下经皮穿刺植入125I放射性粒子联合介入栓塞化疗治疗肾上腺转移瘤的方法及疗效.方法 对12例肾上腺转移瘤患者,应用介入栓塞化疗,2周后复查CT,采用治疗计划系统(TPS)计算剂量和布粒计划,CT定位下行病灶内125I放射性粒子植入术.植入结束后,再次进行CT扫描观察粒子分布情况及有无并发症,评价粒子分布情况.术后2～6个月定期CT随访.结果 术后2、4、6个月随访,12例有效率分别为58.33 %、81.82 %、80.00 %.结论 CT引导下经皮穿刺125I粒子植入联合介入栓塞化疗治疗肾上腺转移瘤安全,损伤小,并发症轻,近期疗效确切,值得推广和应用.     

CT引导下组织间置入125I粒子治疗肺癌的临床应用

目的 介绍CT引导下组织问置入^125I粒子治疗肺癌的技术方法并评价其临床价值。方法 31例肺癌患者均在CT引导下进行肿瘤内^125I粒子置入术。首先根据肿瘤的大小利用放射性粒子治疗计划系统计算出治疗肿瘤所需要^125I粒子的最佳数量，然后经CT引导下经皮穿刺将^125I粒子均匀置入到肿瘤内进行组织间放疗，术后1、2、6个月内分别进行CT检查对患者随访，根据肿瘤大小变化将疗效分为4级：Ⅰ级：明显缓解(肿瘤缩小50％以上)；Ⅱ级：缓解(肿瘤缩小，25％～50％)；Ⅲ级：轻度缓解(肿瘤缩小1％～25％)；Ⅳ级：无效(肿瘤无变化或增大，临床症状亦无缓解)。结果 1个月：Ⅰ级9例，Ⅱ级6例，Ⅲ级13例，Ⅳ级3例(包括1例失访者)，1个月有效率为90．32％；2个月：Ⅰ级17例，Ⅱ级8例，Ⅲ级3例，Ⅳ级3例(包括2例失访者)，2个月有效率为90．32％；6个月：Ⅰ级23例，Ⅱ级3例，Ⅲ级2例，Ⅳ级3例(包括2例失访者)，6个月有效率为90．32％。结论 CT导向下组织间置入^125I粒子是1种治疗肺癌安全、可靠、疗效显著的治疗方法。     

放射性125I粒子植入治疗头颈部肿瘤

目的 探讨超声或CT引导下放射性^125I粒子组织间植入治疗头颈部肿瘤的技术可行性和近期疗效。方法 40例头颈部癌和转移癌患者。4例采用全身麻醉，在CT引导下行^125I粒子植入术；36例采用局部麻醉，行超声引导下^125I粒子植入术。粒子针平行排列，间距1～1．5cm，原发肿瘤植入靶体积影像学边界外放lcm，转移瘤植入靶体积为影像学边界。粒子间距1cm。肿瘤周边匹配剂量（matched peripheral dose，MPD）90～145Gy，每颗粒子活度0．40～0．70mCi，每个病灶植入3～84颗粒子。5例患者术后1周加外放疗，每次200cGy，总剂量45～50Gy。术后24h拍头颈正侧位平片或CT，行质量验证。术后24～48h拍胸部x线片了解有无粒子移位或游走。结果 随访3～33月，10例舌癌3例完全缓解，3例部分缓解，3例稳定，1例进展；2例颈部淋巴结转移的患者经粒子治疗后完全缓解，局部控制率为60％，中位生存期11个月，1年和2年生存率分别为87．50％和35％。14例头颈部癌粒子治疗后，局部控制率为76．47％，中位生存期9个月，1年和2年生存率为66．08％和24％。16例头颈部转移癌粒子治疗后，局部控制率95．23％，中位生存期9个月，1年和2年生存率为54．55％和32．73％。没有1例发生严重的皮肤反应。结论 放射性^125I粒子粒子植入治疗头颈部癌疗效确切，尤其是为那些手术后或放疗复发患者提供了一种新的、可行的、安全和微创治疗手段。     

Comparison of IV contrast-enhanced sonography and histopathology of pancreatic cancer

OBJECTIVE: We compared contrast-enhanced sonography findings with pathologic findings in pancreatic cancer to evaluate the ability of contrast-enhanced sonography to depict the pathologic changes associated with pancreatic cancer. SUBJECTS AND METHODS: Thirty-four patients with pancreatic cancer who underwent surgery were investigated. Sonography was performed with contrast material (Levovist) for all patients before surgery. Pathologic findings were evaluated on the basis of the resected cancer specimens. We compared contrast-enhanced sonography findings with pathologic findings. RESULTS: All tumors that were hyperechoic on contrast-enhanced sonography were papillary adenocarcinoma, and all tumors that were hypoechoic on contrast-enhanced sonography were ductal adenocarcinoma. Among ductal adenocarcinomas, five (71.4%) of seven tumors for which the size of the hypoechoic area was unchanged on contrast-enhanced sonography had clear tumor margins with no infiltration or inflammation in the margin. In contrast, all tumors for which the size of the hypoechoic area was reduced on contrast-enhanced sonography had unclear tumor margins with infiltration of cancerous cells and inflammation. Nine (90%) of 10 tumors that showed partial contrast enhancement or a vascular shadow in a hypoechoic area had large or medium-sized vessels within a tumor at pathology. In contrast, only one (4.8%) of 21 tumors that did not show the vascular shadow in a hypoechoic area had no large or medium-sized vessels in a tumor. CONCLUSION: Contrast-enhanced sonography well reflects the pathologic changes of pancreatic cancer and will provide useful information in a pretreatment evaluation. Further studies with a large number of patients will be required to confirm this finding.     

立体定向放射治疗体部肿瘤(附96例随访分析)

目的:通过临床随访观察,确定用立体定向分次放射治疗(Fractionted Stereotactic Radiotherapy,FSRT)体部肿瘤的近期疗效。对象与方法:96例体部肿瘤患者,其中38例肺癌、12例肝癌、11例胰腺癌、6例纵隔恶性肿瘤、6例食管癌、5例胃癌、5例胆管癌、6例直肠癌、3例宫颈癌和卵巢癌、4例椎骨转移瘤,继确诊和/或手术后,均经x线立体定向分次放射治疗。全部病例中67例(70％)经术前经皮穿刺针吸活组织检查或术后病理组织学检查证实,其余病例由临床、CT和/或磁共振等影像资料证实。用体箱、负压袋固定患者后CT扫描定位,X线立体定向放射治疗计划系统设计并优化治疗计划,加速器旋转照射。部分病人结合常规放射治疗。结果:X线立体定向放射治疗后1～3周内,90例(近94％)表现出临床症状明显改善,而且在此期间未发现1例严重并发症或死亡。肺癌患者随访CT检查32例,其中29例于FSRT后1～6个月肿瘤消失,2例肿瘤体积缩小50％以上,只有1例肿瘤大小无变化,有效率近97％。FSRT对其他肿瘤也有明显疗效,不仅可使原发癌灶缩小或消失,而且可使有癌转移的淋巴结消失。结论:FSRT是一种安全、无痛苦的、且能保持器官原有形态、结构及功能的治疗体部肿瘤的方法,它不仅适合于早期肿瘤患者,而且尤其适合于那些年老体弱,不能耐受手术的或术后残     

Contrast-enhanced ultrasonography depicts small tumor vessels for the evaluation of pancreatic tumors

OBJECTIVE: The aim of this study is to evaluate the efficacy of contrast-enhanced ultrasonography for the diagnosis of pancreatic tumors. MATERIALS AND METHODS: Contrast-enhanced ultrasonography with Levovist was performed on 62 consecutive patients (53 with pancreatic cancer, 4 with islet cell tumor, 3 with inflammatory pancreatic tumor, and 2 with metastatic tumor). The vascular and perfusion image phases of the tumors were evaluated and compared with the findings of contrast-enhanced computed tomography. RESULTS: Contrast-enhanced ultrasonography showed tumor vessels around and/or in the tumor at the vascular image phase in 79% of pancreatic cancer patients (42/53). At the perfusion image phase, 96% of pancreatic cancers (51/53) were classified as hypo-enhancement type. However, tiny spotty or irregular heterogeneous enhanced lesions were found in 84% of hypo-enhanced pancreatic cancer patients (43/51). The presence of small vessels at the vascular image phase was closely correlated with the presence of these intratumor regional enhanced lesions at the perfusion image phase (kappa coefficient=0.42). The sensitivity of contrast-enhanced ultrasonography (100%) for pancreatic cancer was superior to that of contrast-enhanced computed tomography (91%), but no significant difference was observed between the two (McNemar test: p=0.063). CONCLUSION: Contrast-enhanced ultrasonography with Levovist successfully visualizes fine vessels and enhancement in pancreatic tumors, and is useful for evaluating pancreatic tumors.     

Molecular markers,pathology, and ultrasound features of invasive breast cancer

IntroductionUltrasound is commonly used in breast cancer screening and diagnosis. The use of ultrasound features to predict the subtypes of invasive breast cancer is of great clinical significance, since it facilitates a fast and early diagnosis and treatment. The correlation between breast lesion ultrasound features and the breast cancer subtypes requires further investigation.Methods388 patients with invasive breast cancer were retrospectively analyzed by two sonographers. The tumor size, shape, margin, echogenicity, echotexture, posterior echo attenuation microcalcification, and blood vessel density were recorded. The correlation between the tumor ER, PR, HER2, and Ki67 status, the molecular subtypes, and the ultrasound features was analyzed using the chi-square test, Fisher's exact test, and multiple logistic regression.ResultsER and PR positivity were correlated with a low histologic grade, lymph node metastasis, and smaller-sized tumors. A hyperechoic or a mixed echogenicity was rare in the tumors of all groups but was enriched in the ER and PR tumors (9.57% and 7.64%, respectively, p < 0.01). A high percentage of posterior echo attenuation was found in the Ki67 low (53.94%) and ER+ (51.28%) tumors. Furthermore, heterogeneous and microcalcifications were enriched in HER2-positive tumors. In terms of the molecular subtypes, the luminal A subtype group had the lowest lymph node positivity and the smallest primary tumor size. The luminal B subtype had the lowest percentage of hyperechoic or mixed tumors. The HER2 subtype was positively correlated with microcalcification. Finally, TNBC showed the highest percentage of hyperechoic or mixed tumors and the lowest percentage of posterior echo attenuation and microcalcification.ConclusionTumor pathologic and ultrasound features were correlated with invasive breast tumor molecular marker positivity and its molecular subtypes.     

PET—CT在肿瘤放射治疗中的价值

目的探讨PET／CT在放射治疗中的临床应用价值。方法对病理和临床综合检查确诊的178例恶性肿瘤患孝行^18F—FDGPET／CT全身或局部显像,其中头颈部肿瘤15例,肺癌59例,恶性淋巴瘤21例,骨转移瘤55例,脑瘤4例,结、直肠癌4例,转移性淋巴结20例;分析其PET／CT表现,测量兴趣区标准化摄取最大值（SUVmax）,勾画生物靶区,评价肿瘤放疗疗效。结果178例恶性肿瘤患者中新发现淋巴结转移37例;淋巴结伴远处器官转移25例;调整肿瘤的分期62例;勾画生物靶区68例;评估肿瘤放疗后疗效45例：判断放疗后肿瘤残留或复发32例。结论PET／CT在放射治疗应用中具有定性分期准确、勾画生物靶区、判断肿瘤残留、复发和评价疗效等独特优势。     

miR-93在肿瘤发生发展中的作用机制

MicroRNAs(miRNAs)是长约20~25个核苷酸的非编码RNA,在肿瘤中表达异常,发挥癌基因或抑癌基因的作用。miR-93是miR-106b-93-25簇的成员之一,在胃癌、乳腺癌和肺癌等肿瘤中高表达。miR-93通过调节靶基因的表达,参与调控肿瘤细胞增殖、转移和凋亡等过程,因此其表达水平与肿瘤的发生、发展、转移和预后等相关。此外,miR-93的表达还与抗肿瘤药物的耐药性相关。因此miR-93是肿瘤治疗的一个潜在的重要靶点。     

Clinical results of conventional fractionation radiotherapy for glottic and supraglottic laryngeal cancers--the usefulness of hyperfractionation for these cancers

Ninety patients with glottic and eighteen patients with supraglottic laryngeal cancer (anyN, M0) were treated by conventional fractionation radiotherapy between July, 1963 and August, 1988. Tumor control and cause specific survival were evaluated according to tumor location (glottic or supraglottic) and tumor size (T1, T2, T3, or T4). As a result, the steepness of dose-response curve for the tumor control in T1-2 glottic and T2 supraglottic tumors was more slanting upwards than that in other laryngeal tumors, and the patients whose tumors were irradiated at larger doses had a tendency to survive longer. These results suggested that T1-2 glottic and T2 supraglottic laryngeal tumors can have a good application for hyperfractionation radiotherapy which is a radiation therapy with multiple fractions per day with a small fraction size and with which tumors can receive larger radiation doses than with conventional fractionation radiotherapy. Five patients with glottic or supraglottic tumors treated by hyperfractionation radiotherapy obtained CR, and now show no recurrence. We are going to investigate the usefulness of hyperfractionation radiotherapy after treating more patients with Twice-A-Day fractionation radiotherapy.     

Local effect of hyperthermia for superficial and shallow-seated tumors

In approximately seven years, 134 patients with 161 tumors were treated by hyperthermia combined with radiation or chemotherapy at our department. The primary tumors were breast cancer, head and neck cancer, and soft tissue tumors in most patients. Adenocarcinoma was the most frequent, followed by squamous cell carcinoma and soft tissue sarcoma. The local response rates for primary inoperable advanced, metastatic, and local recurrence of breast cancer were 88% (7/8), 50% (10/15), and 86% (18/21), respectively. The local response rate of 39 tumors of neck lymph nodes was 49% (19/39). A total of 26 tumors of bone and soft tissue were treated. Five tumors showed CR and six PR, for a total response rate of 42%. Among 20 patients with malignant melanoma, CR and PR were 25% (5/20) and 30% (6/20), respectively. The local response rate for all patients with superficial and shallow-seated tumors was 58% (94/161). In some tumors classified as showing NR, complete disappearance of tumor cells was demonstrated by a post-treatment histological examination. The efficacy of hyperthermia, when evaluated solely on the basis of tumor size, is likely to be underestimated.     

Phase I trial of the positron-emitting Arg-Gly-Asp (RGD) peptide radioligand 18F-AH111585 in breast cancer patients.

The integrin alpha v beta3 receptor is upregulated on tumor cells and endothelium and plays important roles in angiogenesis and metastasis. Arg-Gly-Asp (RGD) peptide ligands have high affinity for these integrins and can be radiolabeled for PET imaging of angiogenesis or tumor development. We have assessed the safety, stability, and tumor distribution kinetics of a novel radiolabeled RGD-based integrin peptide-polymer conjugate, 18F-AH111585, and its feasibility to detect tumors in metastatic breast cancer patients using PET. METHODS: The biodistribution of 18F-AH111585 was assessed in 18 tumor lesions from 7 patients with metastatic breast cancer by PET, and the PET data were compared with CT results. The metabolic stability of 18F-AH111585 was assessed by chromatography of plasma samples. Regions of interest (ROIs) defined over tumor and normal tissues of the PET images were used to determine the kinetics of radioligand binding in tissues. RESULTS: The radiopharmaceutical and PET procedures were well tolerated in all patients. All 18 tumors detected by CT were visible on the 18F-AH111585 PET images, either as distinct increases in uptake compared with the surrounding normal tissue or, in the case of liver metastases, as regions of deficit uptake because of the high background activity in normal liver tissue. 18F-AH111585 was either homogeneously distributed in the tumors or appeared within the tumor rim, consistent with the pattern of viable peripheral tumor and central necrosis often seen in association with angiogenesis. Increased uptake compared with background (P = 0.002) was demonstrated in metastases in lung, pleura, bone, lymph node, and primary tumor. CONCLUSION: 18F-AH111585 designed to bind the alpha v beta3 integrin is safe, metabolically stable, and retained in tumor tissues and detects breast cancer lesions by PET in most anatomic sites.     

PET with O-(2-18F-Fluoroethyl)-L-Tyrosine in peripheral tumors: first clinical results.

O-(2-18F-Fluoroethyl)-L-Tyrosine (18F-FET) PET has shown promising results in brain tumor diagnosis. The aim of this prospective study was to evaluate 18F-FET PET in comparison with 18F-FDG PET in patients with peripheral tumors. METHODS: Forty-four consecutive patients with suspected malignant tumors underwent 18F-FET PET and 18F-FDG PET within 7 d. Whole-body PET studies were performed 1 h after intravenous injection of 370 MBq of 18F-FET or 18F-FDG. Six patients were excluded from the analysis because a malignant tumor could not be verified. In 38 patients (7 with colorectal cancer, 6 with pancreatic cancer, 9 with head-neck cancer, 4 with lymphomas, 3 with lung cancer, 3 with ovarian cancer, 4 with breast cancer, and 2 with prostatic cancer), 18F-FET PET and 18F-FDG PET were compared. RESULTS: 18F-FET was positive in only 13 of 38 patients (8 with head-neck cancer, 3 with breast cancer, and 2 with lung cancer), whereas 18F-FDG exhibited increased uptake in 37 of 38 patients. All squamous cell carcinomas were found to be 18F-FET-positive tumors (8 head-neck cancer and 2 lung cancer), whereas most adenocarcinomas were found to be 18F-FET-negative tumors. In patients with colorectal cancer, pancreatic cancer, ovarian cancer, prostatic cancer, and lymphomas, no increased 18F-FET uptake could be identified. All lesions that exhibited increased 18F-FET uptake also showed increased 18F-FDG uptake. No additional lesion was identified by 18F-FET PET but not by 18F-FDG PET. A subgroup analysis of patients with head-neck carcinomas allowed a better distinction between malignant and inflammatory tissues with 18F-FET than with 18F-FDG. CONCLUSION: 18F-FET is inferior to 18F-FDG as a PET tracer for general tumor diagnosis. Our preliminary results suggest rather selective uptake of 18F-FET in squamous cell carcinomas. Compared with 18F-FDG PET, 18F-FET PET may allow a better distinction between tumors and inflammatory tissues in patients with squamous cell carcinomas.