Automatic treatment planning of VMAT for left-sided breast cancer with lymph nodes.

Background: The standard in Denmark for treating breast cancer patients receiving loco-regional irradiation is tangential 3D Conformal RadioTherapy (3DCRT), treated in deep inspiration breath-hold (DIBH). Treating with Volumetric Modulated Arc Therapy (VMAT) may reduce the treatment time, which is particularly important for DIBH treatments. The VMAT should be performed without increased dose to the heart, lung, and contralateral breast.

Tumor-site specific geometric distortions in high field integrated magnetic resonance linear accelerator radiotherapy.

Magnetic resonance imaging (MRI) has exquisite soft-tissue contrast and is the foundation for image guided radiotherapy (IGRT) with integrated magnetic resonance linacs. However, MRI suffers from geometrical distortions. In this study the MRI system- and patient-induced geometric distortion at four different tumor-sites was investigated: adrenal gland (7 patients), liver (4 patients), pancreas (6 patients), prostate (20 patients).

Clinical Outcomes of a Randomized Trial of Adaptive Plan-of-the-Day Treatment in Patients Receiving Ultra-hypofractionated Weekly Radiation Therapy for Bladder Cancer.

Purpose: Hypofractionated radiation therapy can be used to treat patients with muscle-invasive bladder cancer unable to have radical therapy. Toxicity is a key concern, but adaptive plan-of the day (POD) image-guided radiation therapy delivery could improve outcomes by minimizing the volume of normal tissue irradiated. The HYBRID trial assessed the multicenter implementation, safety, and efficacy of this strategy.

Quality assuring "Plan of the day" selection in a multicentre adaptive bladder trial: Implementation of a pre-accrual IGRT guidance and assessment module.

Background And Purpose: Hypofractionated bladder RT with or without image guided adaptive planning (HYBRID) is a multicentre clinical trial investigating "Plan of the Day" (PoD) adaptive radiotherapy for bladder cancer. To ensure correct PoD selection a pre-accrual guidance and assessment module was developed as part of an image guided radiotherapy quality assurance (IGRT QA) credentialing programme. This study aimed to evaluate its feasibility and effectiveness across multiple recruiting centres.

Portal dosimetry for VMAT using integrated images obtained during treatment.

Purpose: Portal dosimetry provides an accurate and convenient means of verifying dose delivered to the patient. A simple method for carrying out portal dosimetry for volumetric modulated arc therapy (VMAT) is described, together with phantom measurements demonstrating the validity of the approach.

Methods: Portal images were predicted by projecting dose in the isocentric plane through to the portal image plane, with exponential attenuation and convolution with a double-Gaussian scatter function.

Adaptive-predictive organ localization using cone-beam computed tomography for improved accuracy in external beam radiotherapy for bladder cancer.

Purpose: To examine patterns of bladder wall motion during high-dose hypofractionated bladder radiotherapy and to validate a novel adaptive planning method, A-POLO, to prevent subsequent geographic miss.

Methods And Materials: Patterns of individual bladder filling were obtained with repeat computed tomography planning scans at 0, 15, and 30minutes after voiding. A series of patient-specific plans corresponding to these time-displacement points was created.

Dosimetry audit for a multi-centre IMRT head and neck trial.

Background And Purpose: PARSPORT was a multi-centre randomised trial in the UK which compared Intensity-Modulated Radiotherapy (IMRT) and conventional radiotherapy (CRT) for patients with head and neck cancer. The dosimetry audit goals were to verify the plan delivery in participating centres, ascertain what tolerances were suitable for head and neck IMRT trials and develop an IMRT credentialing program.

Materials And Methods: Centres enrolling patients underwent rigorous quality assurance before joining the trial.

Treatment of lung cancer using volumetric modulated arc therapy and image guidance: a case study.

Background: Volumetric modulated arc therapy (VMAT) is a radiotherapy technique in which the gantry rotates while the beam is on. Gantry speed, multileaf collimator (MLC) leaf position and dose rate vary continuously during the irradiation. For optimum results, this type of treatment should be subject to image guidance.

Treatment of extensive scalp lesions with segmental intensity-modulated photon therapy.

Purpose: To compare static electron therapy, electron arc therapy, and photon intensity-modulated radiation therapy (IMRT) for treatment of extensive scalp lesions and to examine the dosimetric accuracy of the techniques.

Methods And Materials: A retrospective treatment-planning study was performed to evaluate the relative merits of static electron fields, arcing electron fields, and five-field photon IMRT. Thermoluminescent dosimeters (TLD) were used to verify the accuracy of the techniques.