Low-dose CT for lung cancer screening: position paper from the Italian college of thoracic radiology.

Smoking is the main risk factor for lung cancer (LC), which is the leading cause of cancer-related death worldwide. Independent randomized controlled trials, governmental and inter-governmental task forces, and meta-analyses established that LC screening (LCS) with chest low dose computed tomography (LDCT) decreases the mortality of LC in smokers and former smokers, compared to no-screening, especially in women. Accordingly, several Italian initiatives are offering LCS by LDCT and smoking cessation to about 10,000 high-risk subjects, supported by Private or Public Health Institutions, envisaging a possible population-based screening program.

DEVELOPING RADIATION RESISTANT THERMAL NEUTRON DETECTORS FOR THE E_LIBANS PROJECT: PRELIMINARY RESULTS.

Radiation-resistant, gamma-insensitive, active thermal neutron detectors were developed to monitor the thermal neutron cavity of the E_LIBANS project. Silicon and silicon carbide semiconductors, plus vented air ion chambers, were chosen for this purpose. This communication describes the performance of these detectors, owing on the results of dedicated measurement campaigns.

INTENSE THERMAL NEUTRON FIELDS FROM A MEDICAL-TYPE LINAC: THE E_LIBANS PROJECT.

The e_LiBANS project aims at producing intense thermal neutron fields for diverse interdisciplinary irradiation purposes. It makes use of a reconditioned medical electron LINAC, recently installed at the Physics Department and INFN in Torino, coupled to a dedicated photo-converter, developed within this collaboration, that uses (γ,n) reaction within high Z targets. Produced neutrons are then moderated to thermal energies and concentrated in an irradiation volume.

Gamma camera calibrations for the Italian multicentre study for lesion dosimetry in Ra therapy of bone metastases.

Purpose: The aim was to calibrate gamma cameras in the framework of the Italian multicentre study for lesion dosimetry in Ra therapy of bone metastases. Equipments of several manufacturers and different models were used.

Methods: Eleven gamma cameras (3/8- and 5/8-inch crystal) were used, acquiring planar static images with double-peak (82 and 154keV, 20% wide) and MEGP collimator.

H2AX phosphorylation level in peripheral blood mononuclear cells as an event-free survival predictor for bladder cancer.

Bladder cancer (BC) has a typical aetiology characterized by a multistep carcinogenesis due to environmental exposures, genetic susceptibility, and their interaction. Several lines of evidence suggest that DNA repair plays a role in the development and progression of BC. In particular, the study of individual susceptibility to DNA double strand breaks (DSBs) may provide valuable information on BC risk, and help to identify those patients at high-risk of either recurrence or progression of the disease, possibly personalizing both surveillance and treatment.

Implementation of a program for quality assurance on leaf positioning accuracy using Gafchromic(®) RTQA2 films.

In radiotherapy treatments the correct dose delivery to the target volume and the consequent conservation of healthy tissues is affected by multileaf collimator (MLC) leaf positioning accuracy and reproducibility, mostly in intensity-modulated radiation therapy (IMRT): For this reason a quality assurance (QA) program is necessary to ensure the best treatment possible to each patient. The aim of this study is the implementation of a method using Gafchromic(®) RTQA 2 films to perform routine QA on the MLC, both for qualitative and quantitative analysis. A flatbed document scanner (Epson 10000XL) was used in conjunction with radiochromic detector; a scanning protocol was firstly defined to improve readout accuracy.

Complete recovery from paraparesis in spinal cord compression due to extramedullary haemopoiesis in beta-thalassaemia by emergency radiation therapy.

Extramedullary haemopoiesis (EMH) is a complication commonly associated with beta-thalassaemia intermedia; it is frequently asymptomatic but can sometimes lead to symptomatic tumour-like masses. No guidelines or common consensus are available in literature regarding the different treatment strategies and only single cases have been reported. We describe a case of spinal cord compression due to intrathoracic EMH masses treated with combined radiotherapy and hydroxyurea.

Volumetric and positional changes of planning target volumes and organs at risk using computed tomography imaging during intensity-modulated radiation therapy for head-neck cancer: an "old" adaptive radiation therapy approach.

Purpose: This study aimed to assess, in a department of radiation oncology not equipped with in-room imaging systems, volumetric and positional changes of planning target volumes (PTVs) and organs at risk in head and neck (H&N) cancer patients treated with intensity-modulated radiation therapy (IMRT), using consecutive off-board computed tomography (CT) imaging. Dosimetric aspects were not investigated.

Materials And Methods: Ten patients with H&N cancer underwent CT re-scanning at 3, 5, and 7 weeks.

A case of primary mediastinal Ewing's sarcoma / primitive neuroectodermal tumor presenting with initial compression of superior vena cava.

Ewing's sarcomas and peripheral primitive neuroectodermal tumors (ES/PNETs) are high grade malignant neoplasms. These malignancies are characterized by a chromosome 22 rearrangement, arise from bone or soft tissue, predominantly affect children and young adults, and are grouped in the Ewing family of tumors. Multimodality treatment programs are the treatment of choice.

Absolute and relative dose measurements with Gafchromic EBT film for high energy electron beams with different doses per pulse.

The authors have evaluated the accuracy, in absolute and relative dose measurements, of the Gafchromic EBT film in pulsed high-energy electron beams. Typically, the electron beams used in radiotherapy have a dose-per-pulse value of less than 0.1 mGy/pulse.

Dosimetric predictors of radiation-induced lung injury in stereotactic body radiation therapy.

Materials And Methods: The aim was to retrospectively investigate correlations between potential predictive parameters and the occurrence of radiation-induced lung injury in patients with primary or secondary lung tumours treated with stereotactic body radiation therapy (SBRT). Sixty patients (63 tumours) underwent SBRT, with a dose of 45 Gy in 3 fractions over 5 days or 26 Gy in single fraction. The following parameters were tested for correlation with Radiation Therapy Oncology Group (RTOG) lung toxicity score: planning target volume (PTV), tumour location, primary vs.

Clinical use of EBT model Gafchromic film in radiotherapy.

The Gafchromic EBT was recently introduced in film dosimetry for external beam therapy (EBT). The high spatial resolution, weak energy dependence, and near-tissue equivalence of EBT films make them suitable for measurement of dose distributions in radiotherapy, especially intensity-modulated radiation therapy (IMRT). Starting with a sensitometric curve and dose uncertainty relative to the flatbed scanner, the goal of this study was to find an efficient method of correcting for light scattering, and to compare dose distribution supplied by Gafchromic EBT with the distribution obtained with a 2D ion-chamber detector system.

Prostate brachytherapy with iodine-125 seeds: radiation protection issues.

Aims And Background: Brachytherapy for prostate cancer by means of permanently implanted 125I sources is a well established procedure. An increasing number of patients all over the world are treated with this modality. When the technique was introduced at our institution, radiation protection issues relative to this technique were investigated in order to comply with international recommendations and national regulations.

[Characterization of a diode system for in vivo dosimetry with electron beams].

Purpose: Current quality assurance regulation stresses the basic role of in vivo dosimetry. Our study evaluates the usefulness and reliability of semiconductor diodes in determining the electron absorbed dose.

Material And Methods: P-type EDE semiconductor detectors were irradiated with electron beams of different energies produced by a CGR Saturn Therac 20.

[Absorbed doses in dental radiology].

The growing use of dento-maxillo-facial radiographic examinations has been accompanied by the publication of a large number of studies on dosimetry. A thorough review of the literature is presented in this article. Most studies were carried out on tissue equivalent skull phantoms, while only a few were in vivo.

[High-dose-rate brachytherapy. The indications, technic and preliminary results].

The authors report their experience of high dose brachytherapy technique (HDR), relative to the first period of work, especially regarding treatment indications and preliminary clinical results. Twenty eight patients were examined, 12 of them with esophageal carcinoma, 7 biliary tract carcinoma, 6 skin of the face and 3 head and neck carcinoma. HDR brachytherapy was the first treatment in 20 cases; the other 8 cases were recurrences after previous irradiation.

[Total skin therapy with electron beams. II. Clinical results in mycosis fungoides].

Between 1985 and 1989, 19 patients with mycosis fungoides were treated by Total Skin Electron Therapy (TSET). Overall and disease-free survival at 3 years were 72% and 40%. The complete remission (CR) rate was 100% in patients with plaque and 33.

[Total skin therapy with electron beams. I. Physical and geometric factors].

The study pf physical and geometrical factors influencing dose distribution is necessary in performing the Total Skin Electron Therapy. The authors examined some aspects. Photographic emulsions in humanoid phantom were used for dosimetry.

Lateral high abdominal ovariopexy: an original surgical technique for protection of the ovaries during curative radiotherapy for Hodgkin's disease.

An original surgical method for gonadal protection in young women given pelvic radiation for Hodgkin's disease is presented. Lateral high ovarian transposition (LHAO) consists of the transposition of the ovaries into the paracolic gutter during staging laparotomy, after disconnecting the gonads from the fallopian tubes by dividing the tubo-ovarian vessels. The technique's effectiveness was assessed by a study using clinical investigation, radioimmunoassay (RIA) determination of sex hormones, and dosimetry; of 18 patients treated, 10 participated in the study.

[Total cutaneous irradiation with low energy electrons and mycosis fungoides. Technic and dosimetry].

Mycosis fungoides initially involves the epidermis and the superficial layers of derma at a depth of about 1 cm. Wide field irradiation with low energy electrons is therefore the treatment of choice in the initial stages of the disease. In our Institute, total skin electron beam irradiation is delivered with Therac 20 linear accelerator: the lowest available energy is 6 MeV.

[Technic and dosimetry in total body irradiation with 18 MeV photons].

Total body irradiation (TBI) is used in our Institution in the conditioning regimen for bone marrow transplantation. The fractionation pattern consists of two daily fractions of 1.65 Gy repeated for 4 days (total dose 13.

[Comparison of dosimetric protocols for beams of photons and electrons].

In this work we utilize different methods for the calculus of the absorbed dose at different photon and electron energies and we evaluate the difference between their yields. One of these methods is based on the consideration of the factors C lambda e CE (ICRU, HPA, AAPM protocols before 1980); by means of the others (AAPM-Task Group 21, NACP) we seek to obtain a better accuracy introducing new conversion factors. Our measurements were performed using cylindrical and flat ionisation chambers.