Very high-energy electron therapy as light-particle alternative to transmission proton FLASH therapy - An evaluation of dosimetric performances.

Purpose: Clinical translation of FLASH-radiotherapy (RT) to deep-seated tumours is still a technological challenge. One proposed solution consists of using ultra-high dose rate transmission proton (TP) beams of about 200-250 MeV to irradiate the tumour with the flat entrance of the proton depth-dose profile. This work evaluates the dosimetric performance of very high-energy electron (VHEE)-based RT (50-250 MeV) as a potential alternative to TP-based RT for the clinical transfer of the FLASH effect.

Low-Dose Radiation Yields Lower Rates of Pathologic Response in Esophageal Cancer Patients.

Background: Although neoadjuvant chemoradiation (nCRT) followed by surgery is standard treatment for locally advanced esophageal or gastroesophageal junction (E/GEJ) cancer, the optimal radiation dose is still under debate.

Objective: The aim of this study was to assess the impact of different preoperative radiation doses (41.4 Gy, 45 Gy or 50.

3D-conformal very-high energy electron therapy as candidate modality for FLASH-RT: A treatment planning study for glioblastoma and lung cancer.

Background: Pre-clinical ultra-high dose rate (UHDR) electron irradiations on time scales of 100 ms have demonstrated a remarkable sparing of brain and lung tissues while retaining tumor efficacy when compared to conventional dose rate irradiations. While clinically-used gantries and intensity modulation techniques are too slow to match such time scales, novel very-high energy electron (VHEE, 50-250 MeV) radiotherapy (RT) devices using 3D-conformed broad VHEE beams are designed to deliver UHDR treatments that fulfill these timing requirements.

Purpose: To assess the dosimetric plan quality obtained using VHEE-based 3D-conformal RT (3D-CRT) for treatments of glioblastoma and lung cancer patients and compare the resulting treatment plans to those delivered by standard-of-care intensity modulated photon RT (IMRT) techniques.

Effect of Conventional and Ultrahigh Dose Rate FLASH Irradiations on Preclinical Tumor Models: A Systematic Analysis.

Purpose: Compared with conventional dose rate irradiation (CONV), ultrahigh dose rate irradiation (UHDR) has shown superior normal tissue sparing. However, a clinically relevant widening of the therapeutic window by UHDR, termed "FLASH effect," also depends on the tumor toxicity obtained by UHDR. Based on a combined analysis of published literature, the current study examined the hypothesis of tumor isoefficacy for UHDR versus CONV and aimed to identify potential knowledge gaps to inspire future in vivo studies.

Normal Tissue Sparing by FLASH as a Function of Single-Fraction Dose: A Quantitative Analysis.

Purpose: The FLASH effect designates normal tissue sparing by ultra-high dose rate (UHDR) compared with conventional dose rate irradiation without compromising tumor control. Understanding the magnitude of this effect and its dependency on dose are essential requirements for an optimized clinical translation of FLASH radiation therapy. In this context, we evaluated available experimental data on the magnitudes of normal tissue sparing provided by the FLASH effect as a function of dose, and followed a phenomenological data-driven approach for its parameterization.

Fiducial markers for stereotactic lung radiation therapy: review of the transthoracic, endovascular and endobronchial approaches.

Stereotactic body radiation therapy is an alternative to surgery for early-stage, inoperable peripheral non-small cell lung cancer. As opposed to linear accelerator (linac)-based ( gating) and free-breathing techniques, CyberKnife® with Synchrony® technology allows accurate radiation delivery by means of a real-time respiratory motion tracking system using, in most cases, metal fiducial markers (FMs) placed in the vicinity of the target. The aims of this review are as follows.

[Management of abdominal soft tissue sarcomas].

Sarcomas are rare tumors divided into two categories: soft tissue sarcomas and bone sarcomas. A soft tissue mass measuring more than 5 cm, deep, growing, atypical or symptomatic should be investigated further and referred to a specialized center. A percutaneous image-guided biopsy should always be performed in suspicious cases.

Endobronchial coil spring fiducial markers for CyberKnife® stereotactic body radiation therapy.

Background And Objective: SBRT is an alternative treatment for early-stage inoperable lung cancer. Metallic FM allow to increase tumour tracking precision by CyberKnife®. Currently used techniques for FM placement have many limitations; transthoracic insertion has a high risk for pneumothorax, endovascular insertion requires expertise and dedicated angiography infrastructure and endobronchial linear-gold FM dislocate frequently.

Current landscape of palliative radiotherapy for non-small-cell lung cancer.

Radiotherapy (RT) is a cornerstone in the management of advanced stage III and stage IV non-small-cell lung cancer (NSCLC) patients. Despite international guidelines, clinical practice remains heterogeneous. Additionally, the advent of stereotactic ablative RT (SABR) and new systemic treatments such as immunotherapy have shaken up dogmas in the approach of these patients.

Randomized Phase 2 Trial of a Novel Clonidine Mucoadhesive Buccal Tablet for the Amelioration of Oral Mucositis in Patients Treated With Concomitant Chemoradiation Therapy for Head and Neck Cancer.

Purpose: Oral mucositis (OM) is a frequent and painful sequela of concomitant chemoradiation (CRT) used for the treatment of head and neck cancer (HNC) for which there is no effective intervention. This randomized, placebo-controlled study evaluated the efficacy of a novel, mucoadhesive topical tablet formulation of clonidine in mitigating CRT-induced OM in patients with HNC.

Methods And Materials: Patients with HNC undergoing adjuvant radiation therapy (60-66 Gy; 5 × 1.

Total-body irradiation using linac-based volumetric modulated arc therapy: Its clinical accuracy, feasibility and reliability.

Purpose: To report the feasibility, accuracy, and reliability of volumetric modulated arc therapy (VMAT)-based total-body irradiation (TBI) treatment in patients with acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL).

Materials And Methods: From 2015 to 2018, 30 patients with AML or ALL were planned and treated with VMAT-based TBI, which consisted of three isocenters and three overlapping arcs. TBI dose was prescribed to 90% of the planning treatment volume (PTV) receiving 12 Gy in six fractions, at two fractions per day.

Optimization of re-irradiation using deformable registration: a case study.

Re-irradiation is frequently performed in radiotherapy (RT) departments. We present an optimization methodology that takes the previous irradiation into account. A 68-year-old female patient suffering from rectal adenocarcinoma, who had previously undergone RT for metastases to the right iliac bone, presented with a recurrence of metastasis to the L5 and the left sacroiliac joint.

Efficacy and safety of helical tomotherapy with daily image guidance in anal canal cancer patients.

Background and purpose Intensity-modulated radiotherapy (IMRT), also using volumetric modulated arc therapy (VMAT) and helical tomotherapy (HT) techniques, has been only recently introduced for treating anal cancer patients. We report efficacy and safety HT, and daily image-guided RT (IGRT) for anal cancer. Materials and methods We retrospectively analyzed efficacy and toxicity of HT with or without chemotherapy for anal cancer patients.

Radiation-induced CD8 T-lymphocyte Apoptosis as a Predictor of Breast Fibrosis After Radiotherapy: Results of the Prospective Multicenter French Trial.

Background: Monocentric cohorts suggested that radiation-induced CD8 T-lymphocyte apoptosis (RILA) can predict late toxicity after curative intent radiotherapy (RT). We assessed the role of RILA as a predictor of breast fibrosis (bf +) after adjuvant breast RT in a prospective multicenter trial.

Methods: A total of 502 breast-cancer patients (pts) treated by conservative surgery and adjuvant RT were recruited at ten centers.

The reasons for discrepancies in target volume delineation : a SASRO study on head-and-neck and prostate cancers.

Purpose: To understand the reasons for differences in the delineation of target volumes between physicians.

Material And Methods: 18 Swiss radiooncology centers were invited to delineate volumes for one prostate and one head-and-neck case. In addition, a questionnaire was sent to evaluate the differences in the volume definition (GTV [gross tumor volume], CTV [clinical target volume], PTV [planning target volume]), the various estimated margins, and the nodes at risk.

Defining risk levels in locally advanced head and neck cancers: a comparative analysis of concurrent postoperative radiation plus chemotherapy trials of the EORTC (#22931) and RTOG (# 9501).

Background: In 2004, level I evidence was established for the postoperative adjuvant treatment of patients with selected high-risk locally advanced head and neck cancers, with the publication of the results of two trials conducted in Europe (European Organization Research and Treatment of Cancer; EORTC) and the United States (Radiation Therapy Oncology Group; RTOG). Adjuvant chemotherapy-enhanced radiation therapy (CERT) was shown to be more efficacious than postoperative radiotherapy for these tumors in terms of locoregional control and disease-free survival. However, additional studies were needed to identify precisely which patients were most suitable for such intense treatment.