A Voxel-Based Approach to Explore Local Dose Differences Associated With Radiation-Induced Lung Damage.

Purpose: To apply a voxel-based (VB) approach aimed at exploring local dose differences associated with late radiation-induced lung damage (RILD).

Methods And Materials: An interinstitutional database of 98 patients who were Hodgkin lymphoma (HL) survivors treated with postchemotherapy supradiaphragmatic radiation therapy was analyzed in the study. Eighteen patients experienced late RILD, classified according to the Radiation Therapy Oncology Group scoring system.

Modeling the risk of radiation-induced lung fibrosis: Irradiated heart tissue is as important as irradiated lung.

Purpose: We used normal tissue complication probability (NTCP) modeling to explore the impact of heart irradiation on radiation-induced lung fibrosis (RILF).

Materials And Methods: We retrospectively reviewed for RILF 148 consecutive Hodgkin lymphoma (HL) patients treated with sequential chemo-radiotherapy (CHT-RT). Left, right, total lung and heart dose-volume and dose-mass parameters along with clinical, disease and treatment-related characteristics were analyzed.

Twenty years of radiobiology in clinical practice: the Italian contribution.

Aims And Background: To present the Italian state-of-the-art contribution to radiobiology of external beam radiotherapy, brachytherapy, and radionuclide radiotherapy.

Methods And Study Design: A survey of the literature was carried out, using PubMed, by some independent researchers of the Italian group of radiobiology. Each paper was reviewed by researchers of centers not comprising its authors.

Patterns of CT lung injury and toxicity after stereotactic radiotherapy delivered with helical tomotherapy in early stage medically inoperable NSCLC.

Objective: To evaluate toxicity and patterns of radiologic lung injury on CT images after hypofractionated image-guided stereotactic body radiotherapy (SBRT) delivered with helical tomotherapy (HT) in medically early stage inoperable non-small-cell lung cancer (NSCLC).

Methods: 28 elderly patients (31 lesions) with compromised pulmonary reserve were deemed inoperable and enrolled to undergo SBRT. Patterns of lung injury based on CT appearance were assessed at baseline and during follow up.

Hodgkin's lymphoma emerging radiation treatment techniques: trade-offs between late radio-induced toxicities and secondary malignant neoplasms.

Background: Purpose of this study is to explore the trade-offs between radio-induced toxicities and second malignant neoplasm (SMN) induction risk of different emerging radiotherapy techniques for Hodgkin's lymphoma (HL) through a comprehensive dosimetric analysis on a representative clinical model.

Methods: Three different planning target volume (PTVi) scenarios of a female patient with supradiaphragmatic HL were used as models for the purpose of this study. Five treatment radiation techniques were simulated: an anterior-posterior parallel-opposed (AP-PA), a forward intensity modulated (FIMRT), an inverse intensity modulated (IMRT), a Tomotherapy (TOMO), a proton (PRO) technique.

Evaluation of helical tomotherapy in the treatment of high-grade gliomas near critical structures.

Background: Our purpose was to investigate the role of helical tomotherapy using a simultaneous integrated boost technique for the treatment of high-grade gliomas near intracranial critical structures.

Methods And Materials: Of 27 patients treated with helical tomotherapy, 11 were eligible. Only patients whose tumors were within 0.

Radiotherapy for inoperable non-small cell lung cancer using helical tomotherapy.

Aim: To investigate the impact of tomotherapy on the dose delivered to the lungs and other normal tissues.

Material And Methods: From February 2008 to May 2009, 35 patients with stage IIIA/IIIB non-small cell lung cancer were treated with helical tomotherapy at the S. Camillo-Forlanini Hospital.

Comparison of IMRT planning with two-step and one-step optimization: a strategy for improving therapeutic gain and reducing the integral dose.

The aim of this study was to evaluate the effectiveness and efficiency in inverse IMRT planning of one-step optimization with the step-and-shoot (SS) technique as compared to traditional two-step optimization using the sliding windows (SW) technique. The Pinnacle IMRT TPS allows both one-step and two-step approaches. The same beam setup for five head-and-neck tumor patients and dose-volume constraints were applied for all optimization methods.

Role of the parameters involved in the plan optimization based on the generalized equivalent uniform dose and radiobiological implications.

We investigated the role and the weight of the parameters involved in the intensity modulated radiation therapy (IMRT) optimization based on the generalized equivalent uniform dose (gEUD) method, for prostate and head-and-neck plans. We systematically varied the parameters (gEUDmax and weight) involved in the gEUD-based optimization of rectal wall and parotid glands. We found that the proper value of weight factor, still guaranteeing planning treatment volumes coverage, produced similar organs at risks dose-volume (DV) histograms for different gEUDmax with fixed a=1.

Monte Carlo dose calculations using MCNP4C and EGSnrc/BEAMnrc codes to study the energy dependence of the radiochromic film response to beta-emitting sources.

The energy dependence of the radiochromic film (RCF) response to beta-emitting sources was studied by dose theoretical calculations, employing the MCNP4C and EGSnrc/BEAMnrc Monte Carlo codes. Irradiations with virtual monochromatic electron sources, electron and photon clinical beams, a (32)P intravascular brachytherapy (IVB) source and other beta-emitting radioisotopes ((188)Re, (90)Y, (90)Sr/(90)Y,(32)P) were simulated. The MD-55-2 and HS radiochromic films (RCFs) were considered, in a planar or cylindrical irradiation geometry, with water or polystyrene as the surrounding medium.

Comparison of EPR occupational lifetime external dose assessments for Mayak nuclear workers and film badge dose data.

The Mayak worker cohort is one of the major sources of information on health risks due to protracted exposures to plutonium and external ionizing radiation. Electron paramagnetic resonance (EPR) measurements in tooth enamel in combination with personal dose monitoring can help to improve external dose assessment for this cohort. Here, the occupational lifetime external exposure was evaluated individually for 44 nuclear workers of three plants of the Mayak Production Association by EPR measurements of absorbed doses in collected tooth enamel samples.

Monte Carlo calculation and experimental verification of the photon energy response of tooth enamel in a head-sized plexiglas phantom.

The use of electron paramagnetic resonance (EPR) tooth dosimetry for calculation of organ doses requires conversion of the measured absorbed dose in enamel. Before deriving conversion factors from simulation calculations with a realistic anthropomorphic human phantom, in the current study a simplified phantom was chosen to compare EPR measurement and Monte Carlo calculation. The dose response of tooth enamel of molars at various positions inside a cylindrical Plexiglas phantom of head-size was calculated hy Monte Carlo modelling in parallel photon beams of X rays of 63 keV equivalent energy and 60Co gamma rays (1.