Principles and applications of diffusion-weighted imaging in cancer detection, staging, and treatment follow-up

Diffusion-weighted imaging relies on the detection of the random microscopic motion of free water molecules known as Brownian movement. With the development of new magnetic resonance (MR) imaging technologies and stronger diffusion gradients, recent applications of diffusion-weighted imaging in whole-body imaging have attracted considerable attention, especially in the field of oncology. Diffusion-weighted imaging is being established as a pivotal aspect of MR imaging in the evaluation of specific organs, including the breast, liver, kidney, and those in the pelvis. When used in conjunction with apparent diffusion coefficient mapping, diffusion-weighted imaging provides information about the functional environment of water in tissues, thereby augmenting the morphologic information provided by conventional MR imaging. Detected changes include shifts of water from extracellular to intracellular spaces, restriction of cellular membrane permeability, increased cellular density, and disruption of cellular membrane depolarization. These findings are commonly associated with malignancies; therefore, diffusion-weighted imaging has many applications in oncologic imaging and can aid in tumor detection and characterization and in the prediction and assessment of response to therapy.     

Ultrasound in tumor diagnostics and treatment planning (author's transl)]

The fundamental requirements of irradiation planning are discussed delimitating the minimum and maximum demands of planning. Different possibilities to represent the topographic relations within the irradiation plane of the patient's cross-section are described. The computer-assisted system for irradiation planning, installed at our hospital by means of MAT construction, is discussed. A pathway is shown which leads to individual treatment planning and considers dosimetrically the actual conditions of the patient who will undergo radiation therapy. The possibilities and limits of ultrasonic cross-sectional imaging are demonstrated.     

HIFU治疗前列腺癌对血清PMSA水平及特异性细胞免疫功能的影响

目的：研究超声聚能刀（HIFU）治疗前列腺癌对血清前列腺特异性膜抗原（PSMA）水平变化及特异性激活细胞毒性T淋巴细胞活性的影响。方法：8例确诊前列腺癌患者，ELISA法检测HIFU治疗前后血清PSMA，混合淋巴细胞反应检测特异性细胞毒性T淋巴细胞的增殖。结果：HIFU治疗后，血清PSMA升高，并可显著刺激特异性T淋巴细胞增殖，与对照组比较具有显著性差异（P〈0．01）。结论：HIFU治疗可有效激活机体PSMA特异性的T细胞。     

Clinical applications of a CT-simulator: precision treatment planning and portal marking in breast cancer

Breast cancer is frequently treated with radiation using opposed tangent portals to the involved breast, including the chest wall. Presented is a method for simulating such treatment fields on a CT simulator. A short series of CT images provides a three dimensional model for treatment planning prior to marking the patient. Gantry and collimator angles, as well as wedges or custom blocks, are determined in the planning stage. Upon receipt of an approved treatment plan, the portals are available for simulation. The cross-hair laser and computerized bed movement in the CT simulator aid in marking the entrance of the radiation fields on the patient's skin. Discussion of the clinical application of the described technique is included.     

肝癌干细胞表面标志物及其在临床诊疗中的应用研究进展

肝癌是我国最常见的恶性肿瘤之一,具有发病率高和术后易转移的特点,一直是临床医学研究的热点。近年来,从肝癌组织和细胞中发现了多种表面标志物,它们在正常细胞中不表达或低表达,而在肝癌干细胞表面特异性高表达,已经成为肝癌早期诊断和靶向治疗的依据。作者对与肝癌转移和复发相关的肝癌干细胞表面标志物及其在临床诊疗中应用的研究进展进行综述。     

Lung Tumour Induction in Mice after X-rays and Neutrons

Summary

Dose–response curves were determined for pulmonary adenomas and adenocarcinomas in mice after single acute doses of 200 kVp X-rays and cyclotron neutrons (E¯ = 7·5 MeV). A serial-killing experiment established that the radiation induction of chromosome aberrations. The validity of the concept of PLD neous cancers. The dose versus incidence (I) of tumours in male and female mice for X-ray doses between 0·25 and 7·5 Gy is ‘bell-shaped’ and best fitted with a purely quadratic induction and exponential inactivation terms, i.e. I = A + BD²e^?αD. In contrast, the tumour dose–response after 0·1–4·0 Gy of neutrons is best fitted by I = A + BD e^?αD and is steeply linear ≤ 1 Gy, peaks between 1 and 3 Gy and sharply declines at 4·0 Gy. The data for the female mice ≤ 1 Gy neutrons are best fitted to the square root of the dose.

A major objective of the experiments was to derive neutron RBE values. Because of the differences between the X-ray (quadratic) and neutron (linear) curves, the RBE_n will vary inversely with decreasing X-ray dose. The RBE values at 1 Gy of X-rays derived from the B coefficients in the above equations are 7·4 ± 3·2 (male and female); 8·6 ± 3·6 (female) and 4·7 ± 1·8 (male). These are high values and imply even higher values at the doses of interest to radiation protection. If, however, one restricts the analysis to the initial, induction side of the response (≤ 1 Gy neutrons, ≤ 3 Gy X-rays) then good linear fits are obtainable for both radiations and indicate neutron RBE values of 7·4 ± 2·3 for female mice and 4·5 ± 1·8 for males, and these are independent of dose level.     

New ultrasound technologies for the diagnostics of prostate cancer

CLINICAL/METHODOLOGICAL ISSUE: Prostate cancer is the most common cancer in men. The diagnosis is based on prostate-specific antigen (PSA), digital rectal examination (DRE) and transrectal ultrasound (TRUS) guided biopsy. These techniques have considerable limitations, which result in unnecessary biopsies. Furthermore the biopsies are associated with morbidity and costs. STANDARD RADIOLOGICAL METHODS: Standard gray-scale ultrasound has a low sensitivity and specificity for prostate cancer detection. METHODOLOGICAL INNOVATIONS: New ultrasound technologies, including color- and power Doppler ultrasound, contrast enhanced US and real-time sonoelastography have shown to improve prostate cancer diagnosis. PERFORMANCE: Contrast-enhanced ultrasound has shown a sensitivity of 100% (95% CI, 95%), a negative predictive value (NPV) of 99.8% and a positive predictive value (PPV) of 88.8% for prostate cancer detection. Real-time sonoelastography has shown a sensitivity of 86%, a specificity of 81% and NPV of 91% for prostate cancer diagnosis. ACHIEVEMENTS: Most studies show that these new ultrasound modalities demonstrate a 1.5 to 2.5 times higher detection of prostate cancer per biopsy specimen compared with systematic biopsy. Multicenter studies results are at present lacking but are, however ongoing. PRACTICAL RECOMMENDATIONS: In patients with suspected prostate cancer (elevated PSA, suspicious DRE) these new ultrasound techniques should be used. These techniques can detect prostate cancer and allow a targeted biopsy approach.     

Features of clinic, diagnostics and treatment of typhoid fever in young patients

Typhoid fever is a dangerous infection. The article analyzes the clinical aspects, diagnostic possibilities and casual treatment of the young men in organized group with typhoid. It's shown that despite early hospitalization (at average of 5.5 days) the main manifestations peculiar to the "classical" infection retained. The majority (61.5%) had disease of moderate severity, mild form were at 37,4% of patients. Complications occurred in 5.0% of the patients: pneumonia (2.8%), myocarditis (2.2%) and pancreatits (2.2%). Pathogen isolated from patients with typhoid fever had reduced susceptibility to fluoroquinolones. Antimicrobial therapy showed the advantage of the 3 generation cephalosporin (ceftriaxone) compared with ciprofloxacin or a combination of the latter with cefotaxime.     

252Cf瞬发裂变中子及20～60MeV单能中子的比释动能系数

本文基于新发表的氢、碳,氨、氧等介质单能中子比释动能系数,对中子剂量学中常用的一些介质,计算了²⁵²cf瞬发裂变中子及20～60MeV单能中子的比释动能系数,并讨论了组织等效室的有关问题.     

Computer applications in radiation therapy treatment planning

A virtual revolution in computer capability has occurred in the last few years, based largely on rapidly decreasing cost and increasing reliability of digital memory and mass storage capability. These developments have now made it possible to consider the application of both computer and imaging technology to a much broader range of problems in radiation therapy including dose computation, therapy planning and treatment verification. In this paper, a review of the current status in the United States of dose computational algorithms for photon beam and electron beams and treatment planning display is presented.     

Image-based intracavitary brachytherapy in the treatment of inoperable uterine cancer: individual dose specification at specific anatomical sites

PURPOSE: With advances in imaging studies, dose specification for uterine cancer can be defined at specific anatomical sites such as the myometrium or the serosal surface rather than at arbitrary points or milligram-hours. This report presents our experience with image-based brachytherapy for inoperable uterine cancer. METHODS AND MATERIALS: Eight patients with organ-confined uterine cancer (2 Stage I GI, 3 Stage I G2, 3 Stage I G3) underwent definitive radiation therapy because of poor medical condition. All the patients underwent a CT or MRI scan of the pelvis before intracavitary application. Based on the size of the uterine cavity, a single-channel intrauterine applicator was selected for a small uterus, and a multiple-channel intrauterine applicator was used for a large uterus. A CT (n=5) or MRI (n=3) scan of the pelvis was performed with the applicator in place in addition to orthogonal pelvic films. Individualized dose specification was 75Gy to the midmyometrium and limited to 50Gy to the serosal surface of the uterus based on imaging information. RESULTS: Four patients with Stage I G1-2 disease had intracavitary brachytherapy alone. Four patients with Stage I G2-3 disease were treated with a combination of external pelvic radiation and intracavitary brachytherapy. Six patients had low-dose-rate brachytherapy, and 2 patients had high-dose-rate brachytherapy. Five patients had single-channel intrauterine brachytherapy, and 3 patients had multiple-channel brachytherapy. Based on the measurements of the uterine wall thickness by the imaging studies, the dose specification was prescribed to 1.5 cm lateral to the central axis of the uterus in 4 patients, 2.0 cm in 3 patients, and 2.5 cm in 1 patient. The medium followup time after radiation treatment was 38 months. Six patients are alive without evidence of disease, and 2 patients died of other causes. All patients had local control without major side effects. CONCLUSIONS: Image-based brachytherapy based on individualized dose specification at specific anatomical sites can be done easily and provides excellent local control for inoperable uterine cancer.     

Activation of Endogeneous Retroviruses in Mouse Cells by Thermal Neutrons

Summary

The effect of thermal neutrons on the induction of murine endogenous viruses from a mouse fibroblast cell line was investigated. Thermal neutrons were more effective than X-rays in induction of endogenous virus as well as in killing of the cells. However, when measured as a function of cell killing, both radiations had similar efficiency of induction. The RBEs of thermal neutrons alone were calculated on the assumption that the contribution of contaminating γ-rays was additive. It was 4·2 for the killing effect and 4–5 for virus induction.