Genomic Aberrations in Circulating Tumor DNAs from Palbociclib-Treated Metastatic Breast Cancer Patients Reveal a Novel Resistance Mechanism.

Previously undescribed molecular mechanisms of resistance will emerge with the increased use of cyclin-dependent kinase 4/6 inhibitors in clinical settings. To identify genomic aberrations in circulating tumor DNA associated with treatment resistance in palbociclib-treated metastatic breast cancer (MBC) patients, we collected 35 pre- and post-treatment blood samples from 16 patients with estrogen receptor-positive (ER) MBC, including 9 with inflammatory breast cancer (IBC). Circulating cell-free DNAs (cfDNAs) were isolated for sequencing using a targeted panel of 91 genes.

The role of radiation therapy technologist in interventional radiotherapy (brachytherapy) in Italy: Italian Association of Radiotherapy and Clinical Oncology (AIRO) and Italian Association of Radiation Therapy and Medical Physics Technologists (AITRO) joint project.

Purpose: Interventional radiotherapy (IRT, brachytherapy and intra-operative radiotherapy) is a complex treatment approach that requires a multi-professional approach. The aim of this work was to assess the role of radiation therapy technologist (RTT) in IRT team, with a special focus on brachytherapy as well as to define more appropriate ways to improve skills and training to promote cooperation of multi-professional team.

Material And Methods: A nationwide survey consisting of 16 questions was proposed between April and May 2020, with collaboration between the Italian Association of Radiation Therapy and Medical Physics Technologists (AITRO) and the Interventional Radiotherapy Study Group of Italian Association of Radiotherapy and Clinical Oncology (AIRO).

Is it beneficial to use apertures in proton radiosurgery with a scanning beam? A dosimetric comparison in neurinoma and meningioma patients.

Purpose: To assess the dosimetric advantages of apertures in intracranial single fraction proton radiosurgery.

Materials And Methods: Six neuroma and 10 meningioma patients were investigated. For each patient, six plans were computed, with two spot spacing and three aperture settings (no apertures, 5 and 8 mm margin between aperture and clinical target volume [CTV]).

Clinical validation of a GPU-based Monte Carlo dose engine of a commercial treatment planning system for pencil beam scanning proton therapy.

Purpose: To perform the validation of the GPU-based (Graphical Processing Unit based) proton Monte Carlo (MC) dose engine implemented in a commercial TPS (RayStation 10B) and to report final dose calculation times for clinical cases.

Materials And Methods: 440 patients treated at the Proton Therapy Center of Trento, Italy, between 2018 and 2019 were selected for this study. 636 approved plans with 3361 beams computed with the clinically implemented CPU-MC dose engine (version 4.

Rosette-Forming Glioneuronal Tumor of the Fourth Ventricle: A Case of Relapse Treated with Proton Beam Therapy.

Rosette-forming glioneuronal tumors (RGNTs) are rare, grade I, central nervous system (CNS) tumors typically localized to the fourth ventricle. We describe a 9-year-old girl with dizziness and occipital headache. A magnetic resonance imaging (MRI) revealed a large hypodense posterior fossa mass lesion in relation to the vermis, with cystic component.

An avoidance method to minimize dose perturbation effects in proton pencil beam scanning treatment of patients with small high-Z implants.

To implement a multi-field-optimization (MFO) technique for treating patients with high-Z implants in pencil beam scanning proton-therapy and generate treatment plans that avoids small implants. Two main issues were addressed: (i) the assessment of the optimal CT acquisition and segmentation technique to define the dimension of the implant and (ii) the distance of pencil beams from the implant (avoidance margin) to assure that it does not affect dose distribution. Different CT reconstruction protocols (by O-MAR or standard reconstruction and by 12 bit or 16 bit dynamic range) followed by thresholding segmentation were tested on a phantom with lead spheres of different sizes.

Prognostic value of HER2 status on circulating tumor cells in advanced-stage breast cancer patients with HER2-negative tumors.

Purpose: Discordance between HER2 expression in tumor tissue (tHER2) and HER2 status on circulating tumor cells (cHER2) has been reported. It remains largely underexplored whether patients with tHER2/cHER2 can benefit from anti-HER2 targeted therapies.

Methods: cHER2 status was determined in 105 advanced-stage patients with tHER2 breast tumors.

First operation in SPIDER and the path to complete MITICA.

The requirements of ITER neutral beam injectors (1 MeV, 40 A negative deuterium ion current for 1 h) have never been simultaneously attained; therefore, a dedicated Neutral Beam Test Facility (NBTF) was set up at Consorzio RFX (Padova, Italy). The NBTF includes two experiments: SPIDER (Source for the Production of Ions of Deuterium Extracted from Rf plasma), the full-scale prototype of the source of ITER injectors, with a 100 keV accelerator, to investigate and optimize the properties of the ion source; and MITICA, the full-scale prototype of the entire injector, devoted to the issues related to the accelerator, including voltage holding at low gas pressure. The present paper gives an account of the status of the procurements, of the timeline, and of the voltage holding tests and experiments for MITICA.

Modelling the risk of radiation induced alopecia in brain tumor patients treated with scanned proton beams.

Purpose: To develop normal tissue complication probability (NTCP) models for radiation-induced alopecia (RIA) in brain tumor patients treated with proton therapy (PT).

Methods And Materials: We analyzed 116 brain tumor adult patients undergoing scanning beam PT (median dose 54 GyRBE; range 36-72) for CTCAE v.4 grade 2 (G2) acute (≤90 days), late (>90 days) and permanent (>12 months) RIA.

An advanced junction concept in pediatric craniospinal irradiation by proton pencil beam scanning.

Purpose: To present an advanced junction concept in craniospinal irradiation (CSI) by proton pencil beam scanning (PBS).

Materials And Methods: In PBS CSI, whole brain irradiation (WBI) is commonly delivered by opposed lateral-beams, whereas spine irradiation is delivered by posterior entrances. Since lateral-beams would cross a large portion of the patient at the shoulder level, the junction between WBI and spine irradiation cannot extend below that level, thus the size of the lateral-beams needs to be limited and the number of required isocenters can increase.

Potential skin morbidity reduction with intensity-modulated proton therapy for breast cancer with nodal involvement.

Different modern radiation therapy treatment solutions for breast cancer (BC) and regional nodal irradiation (RNI) have been proposed. In this study, we evaluate the potential reduction in radiation-induced skin morbidity obtained by intensity modulated proton therapy (IMPT) compared with intensity modulated photon therapy (IMXT) for left-side BC and RNI. Using CT scans from 10 left-side BC patients, treatment plans were generated using IMXT and IMPT techniques.

A pre-absorber optimization technique for pencil beam scanning proton therapy treatments.

Purpose: To implement a new proton therapy planning method for the treatment of shallow lesions with PBS and to compare it to the standard method.

Methods And Materials: In order to treat shallow lesions, a pre-absorber, usually called range-shifter (RS), is needed: it is used to degrade the beam energy and treat tumors shallower than the minimum range available. Its use is associated to dose calculation uncertainties and plan quality degradation which should be minimized.

Radiation-Induced Moyamoya Syndrome After Proton Therapy in Child with Clival Chordoma: Natural History and Surgical Treatment.

Background: Proton therapy has proven to be effective and safe in the treatment of radioresistant skull base tumors such as chordomas. Thanks to the peculiar physical properties of the proton beam, radiation energy is delivered in a narrow space called the Bragg peak and the surrounding normal tissues receive a minimal amount of the radiation dose. This is important to lower the risk of radiation-induced damage, especially in children.

Association of clinical outcomes in metastatic breast cancer patients with circulating tumour cell and circulating cell-free DNA.

Background: Both circulating tumour cell (CTC) and total circulating cell-free DNA (ccfDNA) predict cancer patient prognosis. However, no study has explored the prognostic value of the combined use of CTC and ccfDNA. We aimed to investigate individual and joint effects of CTC and ccfDNA on clinical outcomes of metastatic breast cancer (MBC) patients.

Impact of dose engine algorithm in pencil beam scanning proton therapy for breast cancer.

Purpose: Proton therapy for the treatment of breast cancer is acquiring increasing interest, due to the potential reduction of radiation-induced side effects such as cardiac and pulmonary toxicity. While several in silico studies demonstrated the gain in plan quality offered by pencil beam scanning (PBS) compared to passive scattering techniques, the related dosimetric uncertainties have been poorly investigated so far.

Methods: Five breast cancer patients were planned with Raystation 6 analytical pencil beam (APB) and Monte Carlo (MC) dose calculation algorithms.

Universal field matching in craniospinal irradiation by a background-dose gradient-optimized method.

Purpose: The gradient-optimized methods are overcoming the traditional feathering methods to plan field junctions in craniospinal irradiation. In this note, a new gradient-optimized technique, based on the use of a background dose, is described.

Methods: Treatment planning was performed by RayStation (RaySearch Laboratories, Stockholm, Sweden) on the CT scans of a pediatric patient.

Supine craniospinal irradiation in pediatric patients by proton pencil beam scanning.

Background And Purpose: Proton therapy is the emerging treatment modality for craniospinal irradiation (CSI) in pediatric patients. Herein, special methods adopted for CSI at proton Therapy Center of Trento by pencil beam scanning (PBS) are comprehensively described.

Materials And Methods: Twelve pediatric patients were treated by proton PBS using two/three isocenters.

Water equivalent thickness of immobilization devices in proton therapy planning - Modelling at treatment planning and validation by measurements with a multi-layer ionization chamber.

Purpose: To investigate the range errors made in treatment planning due to the presence of the immobilization devices along the proton beam path.

Methods: The measured water equivalent thickness (WET) of selected devices was measured by a high-energy spot and a multi-layer ionization chamber and compared with that predicted by treatment planning system (TPS). Two treatment couches, two thermoplastic masks (both un-stretched and stretched) and one headrest were selected.

Steady state thermal-hydraulic analyses of the MITICA cooling circuits.

Megavolt ITER Injector Concept Advancement is the full scale prototype of the heating and current drive neutral beam injectors for ITER, to be built at Consorzio RFX (Padova). The engineering design of its components is challenging: the total heat loads they will be subjected to (expected between 2 and 19 MW), the high heat fluxes (up to 20 MW/m(2)), and the beam pulse duration up to 1 h, set demanding requirements for reliable active cooling circuits. In support of the design, the thermo-hydraulic behavior of each cooling circuit under steady state condition has been investigated by using one-dimensional models.

Nasal cavity reirradiation: a challenging case for comparison between proton therapy and volumetric modulated arc therapy.

Background: The aim of this case report is to report on a dosimetric comparison between volumetric modulated arc therapy (RapidArc technique and active scanning proton therapy (single-field (SFO) and multifield (MFO) techniques) in a case of nasal cavity cancer recurrence.

Case Report: A 72-year-old man, who received adjuvant radiotherapy for a carcinoma of the nasal cavity, experienced an unresectable local recurrence in the previous surgical bed. Hence, the patient was evaluated for reirradiation by comparing different modalities, with a total prescribed dose of 50 Gy in standard fractionation.

Installation of a versatile multiaperture negative ion source.

Neutral Beam Injectors (NBI), which need to be strongly optimized in the perspective of DEMO reactor, request a thorough understanding of the negative ion source used and of the multi-beamlet optics. A relatively compact RF ion source, named NIO1 (Negative Ion Optimization 1), with 9 beam apertures for a total H(-) current of 130 mA, 60 kV acceleration voltage, is being installed at Padua, in Consorzio RFX, to provide a test bench for source optimizations in the framework of the accompanying activities in support to the ITER NBI test facility. NIO1 construction and status of the overall installation, including a high voltage deck and an optical cavity ring down spectrometer are here summarized and reported.

IMRT or 3D-CRT in glioblastoma? A dosimetric criterion for patient selection.

Intensity modulated radiation therapy (IMRT) is increasingly employed in glioblastoma (GBM) treatment. The present work aimed to assess which clinical-dosimetric scenario could benefit the most from IMRT application, with respect to three-dimensional conformal radiation therapy (3D-CRT). The number of organs at risk (OARs) overlapping the planning target volume (PTV) was the parameter describing the clinical-dosimetric pattern.

Helical tomotherapy and intensity modulated proton therapy in the treatment of dominant intraprostatic lesion: a treament planning comparison.

Purpose: To compare helical tomotherapy (HT) and intensity modulated proton therapy (IMPT) for prostate cancer irradiation while concomitantly boosting dominant intraprostatic lesions (DILs).

Methods And Materials: Treatment plans of seven patients were designed for HT and IMPT (pencil beam size: 3mm sigma). The prescribed median PTV/DIL doses were 71.