Multi-centre evaluation of variation in cumulative dose assessment in reirradiation scenarios.

Background And Purpose: Safe reirradiation relies on assessment of cumulative doses to organs at risk (OARs) across multiple treatments. Different clinical pathways can result in inconsistent estimates. Here, we quantified the consistency of cumulative dose to OARs across multi-centre clinical pathways.

Effects of deep inspiration breath hold on prone photon or proton irradiation of breast and regional lymph nodes.

We report on a comparative dosimetrical study between deep inspiration breath hold (DIBH) and shallow breathing (SB) in prone crawl position for photon and proton radiotherapy of whole breast (WB) and locoregional lymph node regions, including the internal mammary chain (LN_MI). We investigate the dosimetrical effects of DIBH in prone crawl position on organs-at-risk for both photon and proton plans. For each modality, we further estimate the effects of lung and heart doses on the mortality risks of different risk profiles of patients.

Benchmarking a commercial proton therapy solution: The Paul Scherrer Institut experience.

Objective: For the past 20 years, Paul Scherrer Institut (PSI) has treated more than 1500 patients with deep-seated tumors using PSI-Plan, an in-house developed treatment planning system (TPS) used for proton beam scanning proton therapy, in combination with its home-built gantries. The goal of the present work is to benchmark the performance of a new TPS/Gantry system for proton therapy centers which have established already a baseline standard of care.

Methods And Materials: A total of 31 cases (=52 plans) distributed around 7 anatomical sites and 12 indications were randomly selected and re-planned using Eclipse™.

Comparison of supine or prone crawl photon or proton breast and regional lymph node radiation therapy including the internal mammary chain.

We report on a dosimetrical study comparing supine (S) and prone-crawl (P) position for radiotherapy of whole breast (WB) and loco-regional lymph node regions, including the internal mammary chain (LN_IM). Six left sided breast cancer patients were CT-simulated in S and P positions and four patients only in P position. Treatment plans were made using non-coplanar volumetric modulated arc photon therapy (VMAT) or pencil beam scanning intensity modulated proton therapy (IMPT).

On the pre-clinical validation of a commercial model-based optimisation engine: application to volumetric modulated arc therapy for patients with lung or prostate cancer.

Purpose: To evaluate the performance of a model-based optimisation process for volumetric modulated arc therapy applied to advanced lung cancer and to low risk prostate carcinoma patients.

Methods And Materials: Two sets each of 27 previously treated patients, were selected to train models for the prediction of dose-volume constraints. The models were validated on the same sets of plans (closed-loop) and on further two sets each of 25 patients not used for the training (open-loop).

Assessment of a model based optimization engine for volumetric modulated arc therapy for patients with advanced hepatocellular cancer.

Background: To evaluate in-silico the performance of a model-based optimization process for volumetric modulated arc therapy (RapidArc) applied to hepatocellular cancer treatments.

Patients And Methods: 45 clinically accepted RA plans were selected to train a knowledge-based engine for the prediction of individualized dose-volume constraints. The model was validated on the same plans used for training (closed-loop) and on a set of other 25 plans not used for the training (open-loop).

Generator breakthrough and radionuclidic purification in automated synthesis of 68Ga-DOTANOC.

68Ga labeled radiopharmaceuticals, like 68Ga-DOATNOC and other similar peptides, are gaining relevance in PET-CT, thanks to relatively easy local generator production, that do not requires an installed cyclotron. However, generator produced 68Ga is typically of suboptimal purity, mainly due to the breakthrough of the parent radionuclide 68Ge. Modern automated synthesis modules adopt both fractionation methods and purification methods in order to get rid of 68Ge breakthrough.