Search results for "Dose Fractionation"

Early Impact of Pulmonary Fractionated Stereotactic Body Radiotherapy on Quality of Life:Benefit for Patients With Low Initial Scores (STRIPE Trial)

2019

Abstract Introduction Quality of life (QoL) of comorbid patients with pulmonary malignancies is a key issue in considering fractionated stereotactic body radiotherapy (SBRT) indication. This study investigates the early impact of SBRT on QoL. Methods One hundred patients with pulmonary lesions were treated with SBRT from February 2011 to December 2014 within the prospective, monocenter, phase II STRIPE trial. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core module (EORTC QLQ-C30) and the QLQ-LC13 lung cancer-specific questionnaire were used to evaluate QoL before, 2 and 7 weeks after SBRT, then every 3 months for 2 years. We report on the ana…

Fractionated Radiation of Primary Prostate Basal Cells Results in Downplay of Interferon Stem Cell and Cell Cycle Checkpoint Signatures

2018

Quantitative changes of metabolic and bioenergetic parameters in experimental tumors during fractionated irradiation.

1999

Abstract Purpose: Previous studies with rat rhabdomyosarcomas indicate that during fractionated irradiation profound alterations of the tumor microvasculature and the oxygenation status occur when the total dose exceeds 45 Gy. At this dose a destruction which included all structures of the vessels and a significant worsening in tumor oxygenation were found. The aim of the present study was to analyze whether these effects of fractionated irradiation on the microvasculature and on tumor oxygenation also induce changes in the bioenergetic and metabolic status in the tumors during radiation treatment. Methods and Materials: R1H rhabdomyosarcomas of the rat implanted into the flank were irradia…

Pimonidazole labelling and response to fractionated irradiation of five human squamous cell carcinoma (hSCC) lines in nude mice: The need for a multi…

2006

To investigate the influence on local control after fractionated radiotherapy of hypoxia measured in unirradiated tumours using the hypoxic marker Pimonidazole, using multivariate approaches.Five human squamous cell carcinoma lines (FaDu, UT-SCC-15, UT-SCC-14, XF354, and UT-SCC-5) were transplanted subcutaneously into the right hind-leg of NMRI nude mice. Histological material was collected from 60 unirradiated tumours after injection of Pimonidazole. The relative hypoxic area within the viable tumour area (Pimonidazole hypoxic fraction, pHF) was determined in seven serial 10 microm cross-sections per tumour by fluorescence microscopy and computerized image analysis. Local tumour control wa…

Long-term quality of life in inoperable non-small cell lung cancer patients treated with conventionally fractionated compared to hyperfractionated ac…

2017

Abstract Background and purpose To evaluate the quality of life (QoL) of patients with inoperable non-small cell lung cancer treated with conventionally fractionated radiotherapy (CF) vs. continuous hyperfractionated accelerated radiotherapy weekend-less (CHARTWEL). Material and methods The largest monocentric subgroup of the phase III CHARTWEL trial was analyzed up to three years after randomization. QoL was assessed with the European Organization for Research and Treatment of Cancer QoL Core Questionnaire (QLQ-C30) and lung cancer module (QLQ-LC13) and compared using linear mixed models. QoL interrelations with recurrence, metastasis, and death were explored by multi-state modeling. Resul…

High-dose-rate brachytherapy boost for prostate cancer: Analysis of dose-volume histogram parameters for predicting late, rectal toxicity

2017

PURPOSE: To determine the significance of dose-volume histogram parameters for predicting late rectal toxicity (LRT) after single-fraction high-dose-rate brachytherapy (HDRBT) boost and external beam radiotherapy (EBRT) in prostate cancer. MATERIALS AND METHODS: Three hundred patients with intermediate- or high-risk prostate cancer were included between August 2010 and March 2015. Treatment comprised a single-fraction HDRBT boost of 15.0 Gy plus EBRT (46.0 Gy delivered in 23 fractions) or an HDRBT boost of 9.5 Gy plus EBRT (60.0 Gy delivered in 30 fractions) if the seminal vesicles were infiltrated using real-time transrectal ultrasound-based planning. LRT was evaluated every 3 months after…

Salvage reirradiation for locoregional failure after radiation therapy for prostate cancer: Who, when, where and how?

2014

Even in the current era of dose-escalated radiotherapy for prostate cancer, biochemical recurrence is not uncommon. Furthermore, biochemical failure is not specific to the site of recurrence. One of the major challenges in the management of prostate cancer patients with biochemical failure after radiotherapy is the early discrimination between those with locoregional recurrence only and those with metastatic disease. While the latter are generally considered incurable, patients with locoregional disease may benefit from emerging treatment options. Ultimately, the objective of salvage therapy is to control disease while ensuring minimal collateral damage, thereby optimizing both cancer and t…

Is high dose rate brachytherapy reliable and effective treatment for prostate cancer patients? A review of the literature.

2014

The intrinsic physical and radiobiological characteristics of High Dose Rate Brachytherapy (HDR-BT) are well suited to the treatment of prostate cancer. HDR-BT was initially used as a boost to external beam brachytherapy, but has subsequently been employed as the sole treatment, which is termed HDR monotherapy. This review summarizes the clinical outcomes and toxicity results of the principal studies and discusses the radiobiological basis supporting its use.

Blood flow and oxygenation status of human tumors. Clinical investigations.

1999

There is a large body of evidence suggesting that blood flow and oxygenation of human tumors are important research topics which may explain, in particular, resistance to radiation and to many antineoplastic drugs, which can limit the curability of solid tumors by radiotherapy and chemotherapy.This manuscript reviews the clinical investigations which have been performed regarding blood flow and oxygenation status of human tumors in radiation oncology.The possible uses and limitations of the prognostic significance and the changes under therapy measuring blood flow and oxygenation in human tumors were discussed. In addition, several approaches were summarized, which can improve the microvasc…

Review of clinical brachytherapy uncertainties: Analysis guidelines of GEC-ESTRO and the AAPM

2014

Background and purpose: A substantial reduction of uncertainties in clinical brachytherapy should result in improved outcome in terms of increased local control and reduced side effects. Types of uncertainties have to be identified, grouped, and quantified. Methods: A detailed literature review was performed to identify uncertainty components and their relative importance to the combined overall uncertainty. Results: Very few components (e.g., source strength and afterloader timer) are independent of clinical disease site and location of administered dose. While the influence of medium on dose calculation can be substantial for low energy sources or non-deeply seated implants, the influence…