An external validation of the Candiolo nomogram in a cohort of prostate cancer patients treated by external-beam radiotherapy.

Background: the aim of this study is to perform an external validation for the Candiolo nomogram, a predictive algorithm of biochemical and clinical recurrences in prostate cancer patients treated by radical Radiotherapy, published in 2016 on the journal "Radiation Oncology".

Methods: 561 patients, treated by Radiotherapy with curative intent between 2003 and 2012, were classified according to the five risk-classes of the Candiolo nomogram and the three risk-classes of the D'Amico classification for comparison. Patients were treated with a mean prostatic dose of 77.

Exploring the variability of radiomic features of lung cancer lesions on unenhanced and contrast-enhanced chest CT imaging.

Purpose: The aim of this methods work is to explore the different behavior of radiomic features resulting by using or not the contrast medium in chest CT imaging of non-small cell lung cancer.

Methods: Chest CT scans, unenhanced and contrast-enhanced, of 17 patients were selected from images collected as part of the staging process. The major T1-T3 lesion was contoured through a semi-automatic approach.

Prostate cancer dose-response, fractionation sensitivity and repopulation parameters evaluation from 25 international radiotherapy outcome data sets.

Objective: This study was undertaken to model the biochemical free survival at 5 years and to evaluate the parameters defining dose-response curve, dose-fractionation radiosensitivity and repopulation.

Methods: It was carried out a literature search on Pubmed to retrieve data sets of patients treated with external beam radiation therapy of 1.8-4.

A new form of the calibration curve in radiochromic dosimetry. Properties and results.

Purpose: This work describes a new form of the calibration curve for radiochromic dosimetry that depends on one fit parameter. Some results are reported to show that the new curve performs as well as those previously used and, more importantly, significantly reduces the dependence on the lot of films, the film orientation on the scanner, and the time after exposure.

Methods: The form of the response curve makes use of the net optical densities ratio against the dose and has been studied by means of the Beer-Lambert law and a simple modeling of the film.

A practical tool to evaluate dose distributions using radiochromic film in radiation oncology.

Purpose: Triple channel algorithm and specific procedures make more reliable radiochromic dosimetry for treatment planning verification and quality assurance in radiation therapy. A tool to obtain radiochromic dose distributions and compare them with the ones resulting from a treatment planning system was developed and applied.

Methods: The tool was developed as Microsoft Excel macro; it builds dose calibration curves against net optical density of Gafchromic EBT3 film, produces axial, coronal and sagittal dose maps and allows to evaluate them against dose distributions calculated by the Varian treatment planning system Eclipse using gamma index and gamma angle.