体内~(31)P磁共振频谱监测乳腺癌治疗反应

体内~(31)P磁共振频谱(~(31)P—MRS)既可测定细胞内低能含磷代谢物,如磷酸单脂(PME)及磷酸二酯(PDE);也可测定高能代谢物,如三磷酸核苷(NTP),包括ATP、磷酸肌酸(Pcr)及无机磷(Pi)。 一例限局性晚期乳腺癌患者,每日服三苯氧胺20mg,尔后行联合化疗。用1.5T Siemens磁共振全身扫描器作频谱来监测,获得肿瘤单独的频谱资料,通过对称lorentzian分布进行峰形分析。     

恶性肿瘤患者新发骨病灶和原发肿瘤的相关性90例活检分析

目的本研究旨在探讨新发骨病灶经活检诊断为其它良性或恶性肿瘤的可能性,以及分析影响骨病灶和原发肿瘤相关性的临床因素。方法回顾性分析2012~2016年接受骨病灶活检的有恶性肿瘤既往史的患者资料。根据病理结果,所有病例分为原发肿瘤骨转移组和非原发肿瘤骨转移组。对病例的年龄、性别、临床症状(如疼痛和神经功能障碍等)、~(18)F-FDG PET/CT(2-deoxy-2-(18F)fluoro-D-glucose Positron Emission Tomography/Computer Tomography)或ECT(emission computed tomography)检查结果、病理结果、累及骨的数量(单骨或多骨)、骨活检的部位以及原发肿瘤和新发骨病灶明确诊断的间隔时间等进行了归纳总结,分析了可能影响新发骨病灶和原发肿瘤相关性的临床因素。结果共有90例有恶性肿瘤既往史的患者进行了骨病灶活检手术,男49例,女41例,平均年龄(56.9±12.8)岁。活检病理结果提示16.7%(15/90)的骨病灶为良性病变(包括1例单纯性骨囊肿,1例动脉瘤样骨囊肿,1例纤维结构不良,1例骨结核和1例孤立性纤维组织肿瘤等),2.2%(2/90)为新发现的恶性肿瘤(1例软骨肉瘤和1例与原发肿瘤无关的癌转移),81.1%(73/90)证实为原发肿瘤骨转移。研究结果表明有临床症状的患者活检结果为原发肿瘤骨转移的比例为85.0%(68/80),明显高于没有临床症状者(50.0%,5/10)(P=0.017)。而两组之间的年龄、性别、原发肿瘤和骨病灶诊断的间隔时间以及~(18)F-FDG PET/CT的SUV_(max)值差异无统计学意义。骨病灶的数量以及部位也不是影响原发肿瘤的新发骨病灶相关性的因素。结论恶性肿瘤患者中新发骨病灶有近20%与原发肿瘤无关,其中有2.2%为新发现的恶性骨肿瘤。临床症状的有无是影响新发骨病灶和原发恶性肿瘤相关性的重要因素。对于恶性肿瘤患者随访过程中新发现的可疑骨病灶,特别是没有临床症状的,应建议积极的活检手术来明确诊断,避免误诊和不当的治疗。     

133例腮腺肿瘤的CT征象分析

背景与目的:腮腺肿瘤大多数生长缓慢,临床上难以估计其良恶性.本研究拟通过对腮腺肿瘤CT征象的分析,以提高CT对腮腺肿瘤的诊断准确率.方法:对经病理证实的133例腮腺肿瘤共157个病灶的CT征象进行回顾性分析,包括病灶的分布、轮廓、边界、强化程度、瘤内囊变坏死、邻近组织的受累情况等.结果:在157个病灶中,良性肿瘤110个(70.0%)、交界性肿瘤18个(11.5%)、恶性肿瘤29个(18.5%).80个(72.7%)良性肿瘤及14个(77.8%)交界性肿瘤位于腮腺浅叶,而恶性肿瘤位于深叶(7/29,24.1%)或跨深浅两叶(10/29,34.5%)的比例明显增加.99个(90.0%)良性肿瘤边缘清楚;交界性肿瘤8个(44.4%)边界清楚,10个(55.6%)部分边界不清;而恶性肿瘤边界部分不清(10/29,34.5%)及边界不清(11/29,37.9%)的比例明显增多.良性肿瘤多呈类圆形(68/110,61.8%)或椭圆形(23/110,20.9%),而恶性肿瘤则多表现为不规则形(14/29,48.3%).11个病灶(2个交界性肿瘤、9个恶性肿瘤)的邻近皮下脂肪受累.腮腺床受累仅见于恶性肿瘤;所有良性肿瘤均未见邻近组织受侵.结论:CT征象可以为腮腺肿瘤的良恶性鉴别诊断提供有价值的依据.位于浅叶、边界清楚、类圆形或椭圆形的腮腺肿瘤多为良性肿瘤;反之,多为恶性肿瘤.     

99mTc-MDP骨显像237例肿瘤患者腰椎病变诊断分析

[目的]研究肿瘤患者99mTc-亚甲基二膦酸盐(MDP)骨显像判断腰椎单一浓集灶良恶性的价值.[方法]237例肿瘤患者行99mTc-亚甲基二膦酸盐(MDP)SPECT显像,磁共振检查;其中32例行99mTc-甲氧基异丁基异腈(MIBI)显像,89例行第二次、第三次99mTc-MDP骨显像.[结果] 237例99mTc-MDP显像显示腰椎单一病灶浓聚,99mTc-MIBI显像示28例腰椎异常部位未见MIBI浓聚,4例腰椎病灶肉眼见低、中度MIBI浓聚,其中1例经磁共振诊断为恶性肿瘤骨转移:随访观察的89例患者中有5例其它部位出现骨转移,腰椎异常浓集部位在随访观察中无明显变化.病灶部位与对侧或相邻正常组织放射性计数比值(I/C)为(1.45±0.40).[结论]有恶性肿瘤病史的患者,99mTc-MDP全身骨显像,腰椎单一部位如摄取MDP略增加或无MIRI摄取,随访观察无明显变化,首先考虑为腰椎良性病变(腰椎退行性变).     

重离子束及其在骨和软组织恶性肿瘤中的应用

骨和软组织恶性肿瘤属于常规射线抗拒性肿瘤.重离子射线12C6+具有高线性能量传递(LET)、Bragg峰、散射小、生物学效应高、对肿瘤细胞损伤以致死性损伤为主、DNA双链断裂等特点,可使肿瘤靶区获得高剂量照射而周围正常组织得到最好保护.近年来,重离子治疗射线抗拒的骨和软组织恶性肿瘤的基础与临床研究均取得了一定进展.     

重视特殊情况下肿瘤骨转移的诊治

恶性肿瘤骨转移是十分常见的现象,诊断和治疗并不十分困难。但在特殊的情况下,如骨病灶和其他部位占位病灶同时出现;或仅有骨的单发或多发病灶,但疾病的良恶性较长时间内难以确定;或骨病灶的性质大致明确,其他部位无病灶可寻;或原发肿瘤已消失多年,新出现骨病灶,此时诊断需要慎重。对于单纯肿瘤骨转移引起的疼痛,有可能出现麻醉性止痛药的过度使用和放疗的应用不足,也需要引起重视。     

乳腺良恶性肿瘤微血管构筑的异质性及其血流动力学的功能变化

目的 探讨乳腺良恶性肿瘤及其不同灌注区域在血管构筑、血流动力学功能、超微结构及其微血管分布方面的差异性.方法 应用实时灰阶超声造影微血管成像(MVI)技术,检测30例乳腺恶性肿瘤(33个病灶)和30例乳腺纤维腺瘤(34个病灶)的微血管造影特征.应用时间-强度曲线(TIC)定量分析技术,检测瘤灶边缘及中心部区域灌注参数及平均灌注参数峰值强度(PI)、曲线下面积(AUC)、达峰时间(TTP)和廓清时间(WOT).应用透射电镜观察瘤内新生血管超微结构改变,应用免疫组化技术检测CD34的表达.结果 乳腺良恶性肿瘤造影后,病灶呈不均匀增强、充盈缺损、紊乱的血管网、血管扩张、血管迂曲征象的差异有统计学意义(P<0.05).恶性组病灶中,TIC多数(29/33,87.9%)呈速升缓降型;良性组病灶中,TIC多数(27/34,79.4%)呈缓升速降型.恶性组平均AUC和WOT大于良性组(P<0.05).两组平均PI和TTP比较,差异无统计学意义(P0.05).恶性组病灶边缘各灌注参数与中心区域相比,差异有统计学意义(P<0.05);良性组病灶边缘各灌注参数与中心区域相比,差异无统计学意义(P>0.05).恶性组新生血管内皮细胞超微结构不同于正常血管内皮细胞,具有分裂旺盛的瘤性特征,痛灶边缘以扩张、迂曲的大血管为多,癌灶中心常见狭窄、闭塞的幼稚新生血管及固缩、变形的内皮细胞和周细胞.恶性组的微血管密度(34.84±8.34)显著高于良性组(18.65±4.69,P<0.05),微血管丰富区位于痛巢边缘.结论 实时超声造影灌注模式、TIC形态、各平均灌注参数及区域灌注参数的差异,为乳腺良恶性肿瘤的鉴别诊断提供了重要依据.肿瘤间质中新生微血管密度、形态、分布、结构及功能的差异性,是影像学评价肿瘤血管生成的基础.     

软组织韧带样型纤维瘤病的影像表现及其病理特征

背景与目的:软组织韧带样型纤维瘤病是一种具有局部侵袭性的少见良性肿瘤,本研究回顾性分析韧带样型纤维瘤病病灶的CT、MRI改变及其病理基础,旨在提高对该肿瘤的诊断水平.方法:29例软组织韧带样型纤维瘤病患者共有34个肿瘤病灶,其中原发性肿瘤20个,复发性肿瘤14个.对7例患者8个肿瘤病灶进行了CT检查,对22例患者26个肿瘤病灶进行了MRI检查.主要分析肿瘤的生长特点、CT及MRI表现,并对肿瘤的组织病理特点进行了分析.结果:肿瘤大小平均为6.5 cm.91.2%(31/34)肿瘤边界不清或部分不清.91.2%(31/34)肿瘤呈分叶状或不规则状.17例(50.0%)肿瘤累及神经血管束,15例(44.1%)肿瘤累及骨质.67.6%(23/34)肿瘤跨解剖间室生长.8个肿瘤病灶中有6个在CT平扫上呈稍低密度,增强后有7个肿瘤病灶呈不均匀强化.26个肿瘤病灶在T1W图像上呈等或稍高信号,T2W图像上呈高信号.88.5%(23/26)肿瘤MRI信号不均匀,肿瘤呈中度或高度强化.22个肿瘤病灶(84.6%)内发现有条索状、片状的T1WI及T2WI上均呈明显低信号改变的区域.光学显微镜下可见肿瘤由梭形细胞和胶原纤维束组成,浸润周围组织结构,梭形细胞周围有胶原纤维包绕.细胞偶见核分裂相,但无病理性核分裂.结论:软组织韧带样型纤维瘤病在CT、MRI表现为肿瘤内无囊变坏死区,瘤内出现T1W、T2W均为低信号的条带影.这是该肿瘤与软组织恶性肿瘤的重要鉴别点.     

PET在骨和软组织肿瘤方面的应用

骨和软组织肿瘤是发生于骨骼或其附属组织(血管、神经、骨髓等)的肿瘤。骨和软组织肿瘤有良性、恶性之分，良性骨肿瘤易根治，预后良好．恶性骨肿瘤发展迅速．预后不佳．死亡率高，至今尚无满意的治疗方法。研究表明，PET对于骨和软组织肿瘤的良恶性鉴别、病变部位的定位、恶性度评价、活检部位的确定、疗效果判断和预后有较好的诊断价值。特别是病变部位进展范围的定位对以手术为主要治疗方法的骨和软组织肿瘤来说非常重要。     

流式细胞小球微阵列术检测恶性肿瘤患者血清六种细胞因子的临床意义

目的探讨流式细胞小球微阵列术(Cytometric Bead Array, CBA)检测恶性肿瘤患者血清干扰素-γ(IFN-γ)、肿瘤坏死因子-α(TNF-α)、白细胞介素(IL-10、IL-5、IL-4、IL-2)含量改变在恶性肿瘤诊断中的意义.方法连续收集各类恶性肿瘤患者共101例,同时设立健康体检组作为对照.采用流式细胞术的微阵列技术代替传统的ELISA方法来检测血清IFN-γ、TNF-α、IL-10、IL-5、IL-4、IL-2的含量,然后分析比较.结果恶性肿瘤组患者血清IFN-γ、TNF-α、IL-10、IL-5、IL-4、IL-2含量分别为(62.05±127.96),(19.53±37.41),(10.68±12.00),(4.43±7.95),(7.32±13.68)和(2.99±9.73)pg/ml;除IL-2外,其余5项均明显高于健康体检组,差异有显著性(P<0.05).IFN-γ、TNF-α、IL-10、IL-5、IL-4、IL-2测定的敏感度分别为72.3%、17.8%、39.6%、85.2%、80.2%和9.9%.大多数恶性肿瘤患者血清中有多种细胞因子水平同时升高,其中以IL-5、IL-4和IFN-γ三种细胞因子均升高最多见,占60.4%,与对照组相比,差异有高度显著性(P<0.01).结论通过对比与分析,细胞因子的单项检测在肿瘤诊断中的意义并不大,但联合检测血清IL-5、IL-4、IFN-γ等的含量在肿瘤临床诊断中有较重要的应用价值.     

Early radiation effects in highly apoptotic murine lymphoma xenografts monitored by 31P magnetic resonance spectroscopy

Purpose: Phosphorus-31 magnetic resonance spectra (³¹P-MRS) were obtained from highly apoptotic murine lymphoma xenografts before and up to 24 hr following graded doses of radiation ranging from 2 to 30 Gy. Radiation-induced apoptosis was also estimated up to 24 hr by scoring apoptotic cells in tumor tissue.Methods and Materials: Highly apoptotic murine lymphoma cells, EL4, were subcutaneously transplanted into C57/BL mice. At 7 days after transplantation, radiation was given to the tumor with a single dose at 3, 10, and 30 Gy. The β-ATP/Pi, PME/Pi, and β-ATP/PME values were calculated from the peak area of each spectrum. Radiation-induced apoptosis was scored with counting apoptotic cells on hematoxylin and eosin stained specimens (%apoptosis).Results: The values of % apoptosis 4, 8, and 24 hr after radiation were 21.8, 19.6, and 4.6% at 3 Gy, 35.1, 25.6, and 14.8% at 10 Gy, 38.4, 38.0, and 30.6% at 30 Gy, respectively (cf. 4.4% in control). There was no correlation between early change in β-ATP/Pi and % apoptosis at 4 hr after radiation when most of the apoptosis occurred. An early decrease in PME/Pi was observed at 4 hr after radiation dose at 30 Gy. For each dose, the values of β-ATP/Pi 24 hr after radiation were inversely related to radiation dose.Conclusion: The increase in β-ATP/Pi observed by ³¹P-MRS was linked to the degree of histological recovery from radiation-induced apoptosis.     

Correlations between in vivo 31P NMR spectroscopy measurements, tumor size, hypoxic fraction and cell survival after radiotherapy

Phosphorus metabolite levels were measured non-invasively using 31P magnetic resonance spectroscopy (MRS) in SCCVII/SF tumors, subcutaneously transplanted into the legs of unanesthetized C3Hf/Sed mice. Shortly after MRS measurements, tumors were irradiated with a single dose of 20 Gy, and cell survival and radiobiologic hypoxic fraction were determined with an in vitro cloning assay. Significant correlations were found between tumor size and surviving fraction, hypoxic fraction, pH, and phosphorus metabolite ratios. With increase of tumor size, surviving fraction and hypoxic fraction both increased, the ratios of inorganic phosphate and phosphomonoesters to nucleoside triphosphates (Pi/NTP and PME/NTP, respectively) and inorganic phosphate to phosphocreatine (Pi/PCr) increased and pH decreased. However, considerable heterogeneity of MRS spectral parameters, even in tumors of similar size, precluded accurate prediction of hypoxic fraction and cell survival after radiotherapy.     

Tumor size dependent changes in a murine fibrosarcoma: use of in vivo 31P NMR for non-invasive evaluation of tumor metabolic status

Tumor tissue contains viable hypoxic regions that are radioresistant and often chemoresistant and may therefore be responsible for some treatment failures. A subject of general interest has been the development of non-invasive means of monitoring tissue oxygen. Pulse Fourier transform 31P NMR spectroscopy can be used to estimate intracellular nucleotide triphosphates (NTP), phosphocreatinine (PCr), inorganic phosphate (Pi) and pH. We have obtained 31P NMR spectra as an indirect estimate of tissue oxygen and metabolic status in a C3H mouse fibrosarcoma FSaII. Sequential spectra were studied during tumor growth in a cohort of animals and peak area ratios for several metabolites were computed digitally by computer. During growth, tumors showed a progressive loss of PCr with increasing Pi, and most tumors greater than 250 mm3 in volume had little or no measurable PCr. The smallest tumors (38 mm3 average volume) had PCr/Pi ratios of 1.03 +/- .24, whereas tumors 250 mm3 or more had an average PCr/Pi ratio of 0.15 +/- .04. Similarly derived NTP/Pi ratios decreased with tumor size, but this change was not significant (p = .17). Radiobiologic hypoxic cell fractions were estimated using the radiation dose required to control tumor in 50% of animals (TCD50) or by the lung colony technique. Tumors less than 100 mm3 had a hypoxic cell fraction of 4% (TCD50) while tumors 250 mm3 had a 40% hypoxic cell fraction (lung colony assay). These hypoxic fraction determinations correlated well with the depletion of PCr and decline in NTP/Pi ratios seen at 250 mm3 tumor volumes. Tumor spectral changes with acute ischemia were studied after ligation of the tumor bearing limb and were similar to changes seen with tumor growth. PCr was lost within 7 minutes, with concurrent increase in Pi and loss of NTP. Complete loss of all high energy phosphates occurred by 40 minutes of occlusion. In vivo tumor 31P NMR spectroscopy can be used to estimate tissue metabolic status and may be useful in non-invasive prediction of hypoxic cell fraction, reoxygenation, and radiation treatment response.     

In vivo 31P-NMR spectroscopy of murine tumours before and after localized hyperthermia

In vivo 31P-NMR spectroscopy was used to monitor the energy metabolism, apparent intracellular pH (pHNMR), and phospholipid turnover in subcutaneous fibrosarcomas (FSall) and mammary carcinomas (MCaIV) treated with hyperthermia (HT). Treatment consisted of elevation of tumour temperature to 43.5 degrees C for 15, 30 or 60 min (FSall) and 30 min (MCaIV). Experiments were performed on conscious mice with biologically relevant tumour sizes. Using water bath immersion, this study focused on acute heat-induced metabolic changes (up to 7 h post-HT). 31P-NMR spectra of both murine tumours were characterized by relatively high pretreatment levels of PME, Pi and NTP, and lower levels of PDE, PCr and DPDE. Following hyperthermia, NTP and PCr levels, as well as pHNMR, decreased in both tumour lines. This drop was accompanied by a prompt and dramatic increase in Pi. After heating for 15 min, the limited spectral changes observed for the high-energy phosphates and the marginal decline in pHNMR were nullified within 7 h, whereas Pi remained significantly elevated. With the exception of PME/NTP and PME/PDE, all relevant metabolic ratios (PCr/Pi, NTP/Pi, PME/Pi) decreased after heating and did not resolve thereafter. Upon longer heat exposure times the high-energy phosphates, pHNMR, NTP/Pi, PCr/Pi, and PME/Pi all decreased in a dose-dependent manner and remained at the respective lower levels. The PME/PDE ratio was increased after 43.5 degrees C/15 min whereas at longer heating times this ratio did not change. At comparable heat doses MCaIV tumours seem to exhibit changes similar to FSall tumours.     

Early radiation effects in highly apoptotic murine lymphoma xenografts monitored by P magnetic resonance spectroscopy

Purpose: Phosphorus-31 magnetic resonance spectra (³¹P-MRS) were obtained from highly apoptotic murine lymphoma xenografts before and up to 24 hr following graded doses of radiation ranging from 2 to 30 Gy. Radiation-induced apoptosis was also estimated up to 24 hr by scoring apoptotic cells in tumor tissue.Methods and Materials: Highly apoptotic murine lymphoma cells, EL4, were subcutaneously transplanted into C57/BL mice. At 7 days after transplantation, radiation was given to the tumor with a single dose at 3, 10, and 30 Gy. The β-ATP/Pi, PME/Pi, and β-ATP/PME values were calculated from the peak area of each spectrum. Radiation-induced apoptosis was scored with counting apoptotic cells on hematoxylin and eosin stained specimens (%apoptosis).Results: The values of % apoptosis 4, 8, and 24 hr after radiation were 21.8, 19.6, and 4.6% at 3 Gy, 35.1, 25.6, and 14.8% at 10 Gy, 38.4, 38.0, and 30.6% at 30 Gy, respectively (cf. 4.4% in control). There was no correlation between early change in β-ATP/Pi and % apoptosis at 4 hr after radiation when most of the apoptosis occurred. An early decrease in PME/Pi was observed at 4 hr after radiation dose at 30 Gy. For each dose, the values of β-ATP/Pi 24 hr after radiation were inversely related to radiation dose.Conclusion: The increase in β-ATP/Pi observed by ³¹P-MRS was linked to the degree of histological recovery from radiation-induced apoptosis.     

彩色多普勒超声对良恶性骨肿瘤的诊断价值

目的 探讨彩色多普勒超声对良恶性骨肿瘤的诊断价值.方法 选取了130例拟诊骨肿瘤患者,根据病情程度分为良性组和恶性组.通过观察患者的血流分级、血流动力学参数、骨皮质连续性、周围软组织浸润情况、超声诊断的准确性,评价彩色多普勒超声对于良恶性骨肿瘤的诊断效果.结果 2组总体血流分级比较,差异具有统计学意义(P<0.05),良性组血流分级多为0级,而恶性组血流分级分布在Ⅱ~Ⅲ级.与恶性组相比,良性组RI和PI值明显较高(P<0.05).与恶性组相比,良性组骨皮质连续性优于恶性组(P<0.05),良性组周围软组织无浸润的情况优于恶性组(P<0.05).超声诊断恶性骨肿瘤符合率95.1%,准确率97.7%.结论 彩色多普勒超声对良、恶性骨肿瘤具有较高的诊断准确度,能清晰地观察到良、恶性骨肿瘤中血流动力学特征及血流分布情况,是良恶性骨肿瘤的首选诊断方式.     

Dietary fat modulation of murine mammary tumor metabolism studied by in vivo 31P-nuclear magnetic resonance spectroscopy

The effect of dietary fat concentration and saturation on high energy phosphate metabolites and phospholipid turnover in transplanted line 168 murine mammary tumors was studied using surface coil 31P-nuclear magnetic resonance spectroscopy. Female BALB/c mice were fed one of five diets each containing at least the minimum of essential fatty acids (EFA). Four diets contained additional safflower or palm oil for a total fat concentration of 5 or 20% by weight. The growth rate of tumors from mice fed the high safflower oil diet was significantly greater than the growth rate of tumors for mice fed all other diets including the one which contained the minimal EFA. 31P-nuclear magnetic resonance-observable phosphate metabolite ratios. ATP/Pi, ATP/phosphomonoester (ATP/PME), and PME/Pi, and tumor pH of line 168 tumors decreased with increasing tumor volume, indicating a shift from active to inactive tumor metabolism. The rates of those decreases with progressive tumor growth differed significantly among tumors of mice fed the different diets. Decreases in ATP/Pi, ATP/PME, and pH were the most rapid in the tumors of mice fed the high safflower oil diet and significantly faster than tumors of mice fed the diet containing minimum EFA. In addition, the decrease in the PME/Pi ratio of tumors was significantly greater in mice fed the high fat (high palm oil and high safflower oil) diets than mice fed the diet containing the minimum of EFA. The rate of decline of ATP/Pi and ATP/PME with progressive tumor growth was directly correlated with levels of linoleic acid as well as total unsaturated fat. High levels of a polyunsaturated fat had a significant effect on mammary tumor metabolism particularly during early stages of tumor growth. Differences in high energy phosphate metabolite dynamics relative to dietary fat were present in tumors of equal volume. Thus, dietary fat influences on mammary tumorigenesis may be related to high energy phosphate metabolites.     

Magnetic resonance angiography without contrast enhancement medium in bone and soft tissue tumors

The aim of this study was to assess the ability of a new magnetic resonance (MR) angiography technique that does not use contrast enhancement medium to depict the vascularity of musculoskeletal neoplasms, and evaluate its clinical utility. We performed 3D fresh blood imaging (FBI) MR angiography in 57 patients with bone or soft tissue tumors, and the detection of vessels in and around the tumor was evaluated. Moreover, differences in vascularity between benign and malignant tumors were analyzed. In the lower leg, large arteries such as femoral or popliteal arteries were visible. In the trunk or arm, large vessels such as subclavian or iliac arteries were visible. Discrimination between benign and malignant tumors was impossible in bone tumors; however, the mean value of vascularity differed between benign and malignant tumors in the soft tissue tumors. This is the first trial of the FBI method for bone and soft tissue tumors. The still developing method of MRA without contrast materials could clearly depict major arteries in the trunk and the extremities, this method may replace conventional MRA of bone and soft tissue tumors because it produces vivid images while being non-invasive.     

Tumors growing in irradiated tissue: oxygenation, metabolic state, and pH

Experimental tumors growing in irradiated tissue have been used to study the biological differences characteristic of locally recurrent tumors. Animal tumors were early generation isotransplants of a spontaneous fibrosarcoma in a C3Hf/Sed mouse, designated FSa-II. Since the hypoxic cell fraction of tumors growing in irradiated tissue is increased, these tumors are assumed to be metabolically deprived with hypoperfusion and acidosis. In this study we directly measured the oxygen partial pressure (pO2) distribution, metabolic state, and pH of tumors growing in an irradiated tumor bed using oxygen sensitive electrodes and 31P-NMR. The results confirmed a three-fold increase in the number of pO2 readings less than or equal to 2.5 mmHg and also showed increased acidosis with a 0.17 unit decrease in pHNMR. When tumors growing in pre-irradiated tissue reached approximately 100 mm3 in volume, a high frequency of gross and microscopic necrosis and hemorrhage was already observed. Consistent with these observations, the phosphocreatine/inorganic phosphate (PCr/Pi) and nucleoside triphosphate/inorganic phosphate (NTP/Pi) ratios were significantly lower in the tumors in a pre-irradiated bed compared to tumors in a non-irradiated bed (PCr/Pi: 0.51 vs 0.79, p less than 0.05; and NTP/Pi: 0.64 vs 0.93, p less than 0.05). The longitudinal relaxation time (T1) of Pi was numerically shorter in control tumors (consistent with the better tissue oxygenation), but this did not reach statistical significance (2.09 +/- .11 sec vs 2.25 +/- .16 sec).