Clinical practice in European centres treating paediatric posterior fossa tumours with pencil beam scanning proton therapy.

Background And Purpose: As no guidelines for pencil beam scanning (PBS) proton therapy (PT) of paediatric posterior fossa (PF) tumours exist to date, this study investigated planning techniques across European PT centres, with special considerations for brainstem and spinal cord sparing.

Materials And Methods: A survey and a treatment planning comparison were initiated across nineteen European PBS-PT centres treating paediatric patients. The survey assessed all aspects of the treatment chain, including but not limited to delineations, dose constraints and treatment planning.

Risk of second primary cancer from proton arc therapy of pediatric brain tumors.

Proton arc therapy (PAT) is currently explored for clinical implementation, despite its associated low-dose bath. This study therefore aimed at evaluating the risk of radiation-induced second primary cancer (SPC) for PAT in pediatric brain tumor patients. Two brain-specific models for SPC induction were applied in five cases to compare volumetric modulated arc therapy (VMAT), intensity modulated proton therapy (IMPT) and PAT surrogate plans.

Histological regression of peritoneal metastases of recurrent tubo-ovarian cancer after systemic chemotherapy.

Introduction: Post-treatment histological regression of peritoneal metastases (PM) is a new and potentially important predictor of oncological outcomes. Histology of PM from adnexal origin is usually evaluated by the Chemotherapy Response Score (CRS). The aim of this preliminary study was to quantify the response of PM of recurrent tubo-ovarian cancer (TOVC) after systemic chemotherapy by using the recently validated Peritoneal Regression Grading System () and compare it with CRS.

[Convalescence after groin hernia surgery].

Inguinal hernia repair represents one of the most common operations in general surgery worldwide. It is performed either as open surgery using a transinguinal approach or as minimal invasive procedure using a preperitoneal (endoscopic) or transabdominal (laparoscopic) approach, respectively. A mesh is always placed to reinforce the abdominal wall of the groin.

Histological regression of gastrointestinal peritoneal metastases after systemic chemotherapy.

Objectives: Peritoneal metastases (PM) are relatively resistant to systemic chemotherapy, and data on histological response to therapy is rare. The aim of this study was to quantify the treatment response of PM after systemic chemotherapy.

Methods: Retrospective monocentric cohort study of 47 consecutive patients with PM from gastrointestinal origin undergoing surgery (cytoreduction: CRS + Hyperthermic IntraPEritoneal Chemotherapy [HIPEC] or Pressurized IntraPeritoneal Aerosol Chemotherapy [PIPAC]) after prior systemic chemotherapy from 1.

Spatial Agreement of Brainstem Dose Distributions Depending on Biological Model in Proton Therapy for Pediatric Brain Tumors.

Purpose: During radiation therapy for pediatric brain tumors, the brainstem is a critical organ at risk, possibly with different radio-sensitivity across its substructures. In proton therapy, treatment planning is currently performed using a constant relative biological effectiveness (RBE) of 1.1 (RBE), whereas preclinical studies point toward spatial variability of this factor.

Variation in relative biological effectiveness for cognitive structures in proton therapy of pediatric brain tumors.

Background: Clinically, a constant value of 1.1 is used for the relative biological effectiveness (RBE) of protons, whereas the RBE has been shown to vary depending on physical dose, tissue type, and linear energy transfer (LET). As the LET increases at the distal end of the proton beam, concerns exist for an elevated RBE in normal tissues.

Comparison between microcatheter and nebulizer for generating Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC).

Background: This study compares an endoscopic microcatheter and a nebulizer for delivering Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC).

Methods: This is an in vitro and ex vivo study in an established model (inverted bovine urinary bladder). Four parameters were compared to determine the performance of a micro-perforated endoscopic spray catheter vs.

Temporal lobe sparing radiotherapy with photons or protons for cognitive function preservation in paediatric craniopharyngioma.

Background And Purpose: Reducing radiation exposure to the temporal lobes could be beneficial to preserve cognitive function in paediatric brain tumour patients. The distribution of doses to brain substructures associated with cognition (BSCs) both within and outside of the temporal lobe have not been reported. The aim of this study was therefore to investigate temporal lobe sparing photon vs.

Towards proton arc therapy: physical and biologically equivalent doses with increasing number of beams in pediatric brain irradiation.

Proton arc therapy may improve physical dose conformity and reduce concerns of elevated linear energy transfer (LET) and relative biological effectiveness (RBE) at the end of the proton range, while offering more degrees of freedom for normal tissue sparing. To explore the potential of proton arc therapy, we studied the effect of increasing the number of beams on physical and biologically equivalent dose conformity in the setting of pediatric brain tumors. A cylindrical phantom (Ø = 150 mm) with central cylindrical targets (Ø = 25 and 30 mm) was planned with increasing number of equiangular coplanar proton beams (from 3 to 36).

Radiation doses to brain substructures associated with cognition in radiotherapy of pediatric brain tumors.

Several brain substructures associated with cognition (BSCs) are located close to typical pediatric brain tumors. Pediatric patients therefore have considerable risks of neurocognitive impairment after brain radiotherapy. In this study, we investigated the radiation doses received by BSCs for three common locations of pediatric brain tumor entities.