A semi‑automated FISH‑based micronucleus‑centromere assay for biomonitoring of hospital workers exposed to low doses of ionizing radiation.

The aim of the present study was to perform cytogenetic analysis by means of a semi‑automated micronucleus‑centromere assay in lymphocytes from medical radiation workers. Two groups of workers receiving the highest occupational doses were selected: 10 nuclear medicine technicians and 10 interventional radiologists/cardiologists. Centromere‑negative micronucleus (MNCM‑) data, obtained from these two groups of medical radiation workers were compared with those obtained in matched controls.

Bioeffect modeling and equieffective dose concepts in radiation oncology--terminology, quantities and units.

The International Commission on Radiation Units and Measurements (ICRU) Report Committee on "Bioeffect Modeling and Biologically Equivalent Dose Concepts in Radiation Therapy" is currently developing a comprehensive and consistent framework for radiobiological effect modeling based on the equieffective dose, EQDX(α/β), a concept encompassing BED and EQD2 as special cases.

PTV margins should not be used to compensate for uncertainties in 3D image guided intracavitary brachytherapy.

The planning target volume (PTV) concept has been created within the context of external beam radiotherapy (EBRT). It would be ideal to have a similar approach in brachytherapy (BT) to compensate for uncertainties. However, the BT and EBRT dose distributions are profoundly different, and the role of a PTV concept in BT needs a distinct discussion.

[Radiologic exposure of the dental patient: comparison of the doses delivered by different techniques].

This paper evaluates the doses delivered to the patient during several radiological procedures in dentistry: intraoral, panoramic and cephalometric radiography. Different digital techniques now available are compared to the AgBr film and film-screen technique. Absorbed doses at different organs are derived from measurements on dental radiological phantoms.

What's new in target volume definition for radiologists in ICRU Report 71? How can the ICRU volume definitions be integrated in clinical practice?

The optimal definition of the size, shape and location of gross tumour volume is one of the most important steps in the planning of radiation therapy, and necessitates a proper understanding of the procedure from both the oncologic radiologist and the radiation oncologist. This overview reports on the different terms and concepts that have been recommended in the ICRU Reports for this purpose; the latest Report 71 focuses on both previously given recommendations, and especially on electron beam therapy. This paper also highlights some of the problems that are encountered in the use of the International Commission on Radiation Units and Measurements (ICRU) recommendations in clinical practice, and at the interface between the radiation oncologist and the diagnostic oncologist.

Comparison of the Methods of Specifying Carbon Ion Doses at NIRS and GSI.

Due to the RBE variations, the carbon-ion doses (in Gy) are no longer sufficient to monitor adequately the biological effect of these radiations. Therefore, "RBE dose weighting factors" - W(RBE) - allowing for the RBE variations with energy, dose and biological system have to be introduced in the treatment plans in order to provide the physician with interpretable information. This paper compares the methods employed for this purpose at NIRS and GSI, which are specific of the beam delivery system of these institutions.

3-D Conformal radiotherapy of localized prostate cancer within an Austrian-German multicenter trial: a prospective study of patients' acceptance of the rectal balloon during treatment.

Purpose: Patients with localized prostate cancer are treated with 3D radiotherapy using a rectal balloon catheter for internal immobilization of the prostate, thereby reducing the radiation dose to the dorsal rectal wall. The purpose of the study was to investigate clinical feasibility and the influence of acute rectal side effects and pre-existing hemorrhoids on patients' acceptance of the rectal balloon catheter.

Methods And Materials: 442 patients who underwent primary radiation therapy for localized prostate cancer were included in this prospective Austrian-German multicenter trial.

3-D conformal radiotherapy of localized prostate cancer: a subgroup analysis of rectoscopic findings prior to radiotherapy and acute/late rectal side effects.

Background And Purpose: To identify endoscopic pathological findings prior to radiotherapy and a possible correlation with acute or chronic rectal side effects after three-dimensional conformal radiotherapy (3D-CRT) for prostate cancer.

Patients And Methods: Between 03/99 and 07/02, a total of 298 patients, who consented in a voluntary rectoscopy prior to radiotherapy were included into the analysis. Patients were treated with a total dose of either 70 or 74 Gy.

In-vivo dosimetry for gynaecological brachytherapy: physical and clinical considerations.

Introduction: The study aimed to estimate the dosimetric uncertainty using diodes (PTW/Germany) for a high-dose rate Iridum-192 source under clinical conditions. Finally, the role of in-vivo dosimetry for cervix cancer patients was evaluated.

Material And Methods: First, diode calibration and factors influencing diode response were investigated and phantom studies compared doses measured and computed by the treatment planning system.

RBE and weighting of absorbed dose in ion-beam therapy.

Absorbed dose is the fundamental quantity used to quantify the exposure of any biological system to ionizing radiation. However, the relationship between dose and biological effect is not unique but varies with fractionation and time factor(s), radiation quality and irradiation conditions. In radiation therapy, weighting factors are used to correlate absorbed dose and clinical effects when altering irradiation conditions, or for combining or comparing different technical modalities.

Intestinal crypt regeneration in mice: a biological system for quality assurance in non-conventional radiation therapy.

Background And Purpose: The Relative Biological Effectiveness (RBE) of 8 fast-neutron beams, 5 proton beams and 1 carbonion beam was determined using as biological criterion intestinal crypt regeneration in mice, i.e. an in vivo system.

General principles for prescribing, recording and reporting a therapeutic irradiation.

Exchange of clinical information is essential for the development and progress in radiation oncology. This goal can be achieved only through a general harmonization on methods of reporting. The ICRU has been involved for several decades in a continuous effort to harmonize reporting of dose and to standardize methods used to determine the doses and points or volumes where these doses are delivered.

Radiobiological rationale and patient selection for high-LET radiation in cancer therapy.

The rationale for introducing ion beams in cancer therapy is the high level of physical selectivity that can be achieved with ions, equal or even better than with proton beams or modern photon techniques, as well as the potential advantage of high-LET radiations for some tumour types and sites. The radiobiological arguments for high-LET radiation in cancer therapy are reviewed: reduction of OER in the case of hypoxic and poorly-reoxygenating tumours, and the lesser importance of repair phenomena which are a problem in controlling repair-proficient photon-resistant tumours. Fast neutrons were the first type of high-LET radiation used clinically, and were often applied under suboptimal technical conditions.

Relative biologic effectiveness determination in mouse intestine for scanning proton beam at Paul Scherrer Institute, Switzerland. Influence of motion.

Purpose: To determine the relative biologic effectiveness (RBE) of the Paul Scherrer Institute (PSI) scanning proton beam in reference conditions and to evaluate the influence of intestine motion on the proton dose homogeneity.

Methods And Materials: First, RBE was determined for crypt regeneration in mice after irradiation in a single fraction. Irradiation was performed at the middle of a 7-cm spread out Bragg peak (SOBP; reference position), as well as in the proximal part of the plateau and at the distal end of the SOBP.