Purpose: The proximity or overlap of planning target volume (PTV) and organs-at-risk (OARs) poses a major challenge in stereotactic body radiation therapy (SBRT) of pancreatic cancer (PACA). This international treatment planning benchmark study investigates whether simultaneous integrated boost (SIB) and simultaneous integrated protection (SIP) concepts in PACA SBRT can lead to improved and harmonized plan quality.
Methods And Materials: A multiparametric specification of desired target doses (gross target volume [GTV], GTV, PTV, and PTV) with 2 prescription doses of GTV = 5 × 9.
Background: In stereotactic radiotherapy, dose is prescribed to an isodose surrounding the planning target volume (PTV). However, the desired dose inhomogeneity inside the PTV leaves the specific dose distribution to the gross tumor volume (GTV) unspecified. A simultaneously integrated boost (SIB) to the GTV could solve this shortcoming.
View Article and Find Full Text PDFBackground: Small-cell lung cancer (SCLC) is a malignant tumor known for its poor prognosis. In addition to chemotherapy and immunotherapy irradiation plays a big role especially in inoperability. This study evaluated prognostic factors in patients with SCLC, receiving chemotherapy and thoracic irradiation, that may affect overall survival (OS), progression-free survival (PFS) and toxicity.
View Article and Find Full Text PDFInt J Radiat Oncol Biol Phys
May 2022
Purpose: Our purpose was to investigate whether liver stereotactic body radiation therapy treatment planning can be harmonized across different treatment planning systems, delivery techniques, and institutions by using a specific prescription method and to minimize the knowledge gap concerning intersystem and interuser differences. We provide best practice guidelines for all used techniques.
Methods And Materials: A multiparametric specification of target dose (gross target volume [GTV], GTV, GTV, planning target volume [PTV]) with a prescription dose of GTV = 3 × 20 Gy and organ-at-risk (OAR) limits were distributed with computed tomography and structure sets from 3 patients with liver metastases.
To report outcome (freedom from local progression [FFLP], overall survival [OS] and toxicity) after stereotactic, palliative or highly conformal fractionated (>12) radiotherapy (SBRT, Pall-RT, 3DCRT/IMRT) for adrenal metastases in a retrospective multicenter cohort within the framework of the German Society for Radiation Oncology (DEGRO). Adrenal metastases treated with SBRT (≤12 fractions, biologically effective dose [BED10] ≥ 50 Gy), 3DCRT/IMRT (>12 fractions, BED10 ≥ 50 Gy) or Pall-RT (BED10 < 50 Gy) were eligible for this analysis. In addition to unadjusted FFLP (Kaplan-Meier/log-rank), we calculated the competing-risk-adjusted local recurrence rate (CRA-LRR).
View Article and Find Full Text PDFPurpose: This multi-institutional study investigates whether computational verification of fluence-modulated treatment plans using independent software with its own Strahlerkopfmodel is an appropriate method for patient-related quality assurance (PRQA) in the context of various combinations of linear accelerators (linacs), treatment techniques and treatment planning systems (TPS).
Materials And Methods: The PRQA-software's (Mobius3D) recalculations of 9 institutions' treatment plans were analyzed for a horseshoe-shaped planning target volume (PTV) inside a phantom. The recomputed dose distributions were compared to a) the dose distributions as calculated by all TPS's and b) the measured dose distributions, which were acquired using the same independent measuring system for all institutions.
Purpose: The aim was to evaluate stereotactic body radiation therapy (SBRT) treatment planning variability for early stage nonsmall cell lung cancer (NSCLC) with respect to the published guidelines of the Stereotactic Radiotherapy Working Group of the German Society for Radiation Oncology (DEGRO).
Materials And Methods: Planning computed tomography (CT) scan and the structure sets (planning target volume, PTV; organs at risk, OARs) of 3 patients with early stage NSCLC were sent to 22 radiotherapy departments with SBRT experience: each department was asked to prepare a treatment plan according to the DEGRO guidelines. The prescription dose was 3 fractions of 15 Gy to the 65% isodose.
Purpose: This project compares the different patient-related quality assurance systems for intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) techniques currently used in the central Germany area with an independent measuring system.
Materials And Methods: The participating institutions generated 21 treatment plans with different combinations of treatment planning systems (TPS) and linear accelerators (LINAC) for the QUASIMODO (Quality ASsurance of Intensity MODulated radiation Oncology) patient model. The plans were exposed to the ArcCHECK measuring system (Sun Nuclear Corporation, Melbourne, FL, USA).
The co-incidence of synchronous intraepithelial neoplasia and early stage invasive lung cancer is not a rare phenomenon. The need for curative treatment and the invasive potential of squamous cell pulmonary carcinoma in situ have been a topic of controversy. Surgical resection still remains the treatment of choice.
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