Conversion of measured percentage depth dose to tissue maximum ratio values in stereotactic radiotherapy.

For many treatment planning systems tissue maximum ratios (TMR) are required as input. These tissue maximum ratios can be measured with a 3D computer-controlled water phantom; however, a TMR measurement option is not always available on such a system. Alternatively TMR values can be measured 'manually' by lowering the detector and raising the water phantom with the same distance, but this makes TMR measurements time consuming.

Improved antitumor response to isolated limb perfusion with tumor necrosis factor after upregulation of endothelial monocyte-activating polypeptide II in soft tissue sarcoma.

Background: Experiments with tumor necrosis factor alpha (TNF) in rodents have shown that a high dose can lead to hemorrhagic necrosis in tumors. Endothelial monocyte-activating polypeptide II (EMAP-II) is a novel tumor-derived cytokine, and its expression increases the TNF-1 receptor on tumor endothelium, enhances the induction of tissue factor on tumor endothelial cells, and has an antiangiogenic effect. It has recently been shown that in vivo sensitivity of tumor vasculature to TNF is determined by tumor production of EMAP-II.

Ferumoxide-enhanced magnetic resonance imaging techniques in pre-operative assessment for colorectal liver metastases.

Aim: The objective was to evaluate whether contrast-enhanced magnetic resonance imaging (MRI) techniques used in a pre-operative assessment protocol for colorectal liver metastases are as accurate as spiral computer tomography during arterial portography (CTAP). Pre-operative accuracy and clinical consequences of MRI are described and compared with CTAP. Moreover, post-operative survival rate and tumour recurrence were studied.

Clinical experience of prophylactic mastectomy followed by immediate breast reconstruction in women at hereditary risk of breast cancer (HB(O)C) or a proven BRCA1 and BRCA2 germ-line mutation.

Aim: Women with a proven BRCA1 or BRCA2 germ-line mutation or with a 50% risk of carrying the mutation, have an increased risk of breast cancer. Regular surveillance, chemoprevention or prophylactic mastectomy (PM) are options to detect breast cancer at an early stage or to reduce the risk. We describe the management of women who have opted for PM, the postoperative complications of PM, especially in combination with immediate breast reconstruction (IBR), and the oncological follow-up.

A prospective study on silicone breast implants and the silicone-related symptom complex.

This cohort study prospectively evaluated the prevalence of the silicone-related symptom complex (SRSC) in relation to antinuclear antibodies (ANA) and magnetic resonance imaging (MRI) of silicone breast implants (SBI) 1 year after implantation. A total of 57 women undergoing mastectomy followed by immediate breast reconstruction (IBR) and SBI between March 1995 and March 1997 at the University Hospital Rotterdam/Daniel den Hoed Cancer Centre, were prospectively evaluated. Just before and 1 year after IBR the sera of these women were tested for the presence of ANA and they were screened for the prevalence of SRSC-related symptoms by questionnaire.

Prerequisites for effective adenovirus mediated gene therapy of colorectal liver metastases in the rat using an intracellular neutralizing antibody fragment to p21-Ras.

Ras mutations are present in 40-50% of colorectal cancers. Inactivating this oncogene may therefore reduce proliferation capacity. In order to target ras we studied the transduction efficacy and anti tumour activity of an adenoviral vector expressing an intracellular, neutralizing single chain antibody to p21-ras (Y28).

Molecular quantification of viral load in plasma allows for fast and accurate prediction of response to therapy of Epstein-Barr virus-associated lymphoproliferative disease after allogeneic stem cell transplantation.

Epstein-Barr virus lymphoproliferative disease (EBV-LPD) following allogeneic stem cell transplantation (allo-SCT) has a poor prognosis. We used a sensitive real-time polymerase chain reaction (PCR) assay for quantitative detection of EBV-DNA in plasma and serially measured EBV-DNA levels to assess the response to treatment in allo-SCT recipients with EBV-LPD. Fourteen allo-SCT recipients with EBV-LPD who received a T cell-depleted (TCD) sibling (n = 5) or matched unrelated donor (n = 9) graft were monitored from the time of EBV-LPD diagnosis, during therapy and assessment of clinical response.

Single dose irradiation response of pig skin: a comparison of brachytherapy using a single, high dose rate iridium-192 stepping source with 200 kV X-rays.

An experimental brachytherapy model has been developed to study acute and late normal tissue reactions as a tool to examine the effects of clinically relevant multifractionation schedules. Pig skin was used as a model since its morphology, structure, cell kinetics and radiation-induced responses are similar to human skin. Brachytherapy was performed using a microSelectron high dose rate (HDR) afterloading machine with a single stepping source and a custom-made template.

Nitric oxide synthase inhibition results in synergistic anti-tumour activity with melphalan and tumour necrosis factor alpha-based isolated limb perfusions.

Nitric oxide (NO) is an important molecule in regulating tumour blood flow and stimulating tumour angiogenesis. Inhibition of NO synthase by L-NAME might induce an anti-tumour effect by limiting nutrients and oxygen to reach tumour tissue or affecting vascular growth. The anti-tumour effect of L-NAME after systemic administration was studied in a renal subcapsular CC531 adenocarcinoma model in rats.

Earlier detection of breast cancer by surveillance of women at familial risk.

A positive family history increases the risk for breast cancer which oft en occurs at a much younger age than in the general population. We stud ied whether surveillance of these women resulted in the detection of bre ast cancer in an earlier stage than in symptomatic patients with a famil y history. Between January 1994 and April 1998, 294 women with 15-25% r isk (moderate), mean age:43.

Immunocytochemical detection of prognostic markers in breast cancer; technical considerations.

The purpose of this study was to establish a good technical procedure for immunocytochemical (IC) staining of prognostic markers in breast cancer specimens. The influence of various preparation, fixation and storage methods on ER, P53 and Ki-67 IC staining was assessed, using cells of two breast cancer cell lines T47D (ER/P53+) and ZR-75-ER (ER+, P53-). In addition we searched for a suitable transport medium.

Cost of care in a randomised trial of early hospital discharge after surgery for breast cancer.

The aim of this study was to determine the effect of the reduction of the length of hospital stay after surgery for breast cancer on the rate of care consumption and the cost of care. Patients with operable breast cancer were randomised to a short or long postoperative hospital stay. Data on care consumption were collected for a period of 4 months in diaries administered by patients, and socioeconomic status was evaluated by questionnaires.

Monte Carlo simulations for EndoBronchial Photodynamic Therapy: the influence of variations in optical and geometrical properties and of realistic and eccentric light sources.

Background And Objective: Light dosimetry for endobronchial photodynamic therapy is not very advanced to date. This study investigates the dependency of the fluence rate distribution in the bronchial wall on several parameters.

Study Design/materials And Methods: A Monte Carlo model is employed for the illumination of a cylindrical cavity by a linear diffuser to compute the fluence rate distribution in the tissue.