Effect of inaccurate small field output factors on brain SRS plans.

External beam radiotherapy often includes the use of field sizes 3 × 3 cmor less, which can be defined as small fields. Dosimetry is a difficult, yet important part of the radiotherapy process. The dosimetry of small fields has additional challenges, which can lead to treatment inconsistencies if not done properly.

A Practical Radiotherapy Treatment Planning Technique for Second-Incidence Cancers That Incorporates Complete Organ-At-Risk Dose History.

Introduction: Patients requiring treatment for second cancer incidences present unique radiotherapy plan development challenges. Historical dose delivered to organs at risk must be accounted for to properly estimate lifetime toxicity risks, but historical dose delivered to the region now occupied by tumours does not contribute to the prescription dose. Treatment planning systems permit inclusion of a base plan but do not provide the ability to manipulate it.

Template-based Intensity-Modulated Radiation Therapy: A Cost-effective Intensity-Modulated Radiation Therapy Planning Procedure for Prostate Cancer.

Introduction: Intensity-modulated radiation therapy (IMRT) has been widely accepted for the treatment of prostate cancer. In comparison with traditional three-dimensional conformal radiation therapy (3D-CRT), it improves local control while minimizing side effects. However, IMRT comes at a significantly higher cost.

The quality assurance of volumetric modulated arc therapy (VMAT) plans for early stage prostate cancer: a technical note.

As radiation therapy transitions from intensity modulated radiation therapy (IMRT) to volumetric modulated arc therapy (VMAT) it is important to consider the quality assurance (QA) of VMAT plans in light of what has previously been learned and developed in IMRT QA. This technical note assesses if IMRT based plan QA software, which has reduced the need in IMRT for phantom dose measurements on the linear accelerator, can be incorporated into VMAT QA processes. Twenty prostate cases were retrospectively planned using VMAT with one arc to deliver a prescription of 74 Gy in 37 fractions.

On using the dosimetric leaf gap to model the rounded leaf ends in VMAT/RapidArc plans.

Partial transmission through rounded leaf ends of Varian multileaf collimators (MLC) is accounted for with a parameter called the dosimetric leaf gap (DLG). Verification of the value of the DLG is needed when the dose delivery is accompanied by gantry rotation in VMAT plans. We compared the doses measured with GAFCHROMIC film and an ionization chamber to treatment planning system (TPS) calculations to identify the optimum values of the DLG in clinical plans of the whole brain with metastases transferred to a phantom.

A Retrospective Planning Analysis Comparing Volumetric-Modulated Arc Therapy (VMAT) to Intensity-Modulated Radiation Therapy (IMRT) for Radiotherapy Treatment of Prostate Cancer.

Purpose: This study aims to compare intensity-modulated radiation therapy (IMRT) to volumetric-modulated arc therapy (VMAT) for the treatment of prostate cancer. Particular focus was placed on the impact IMRT and VMAT have on departmental planning and treatment resources.

Materials And Methods: Twenty prostate cancer cases were retrospectively planned to compare 5-field IMRT to VMAT using a single arc (VMAT-1A) and 2 arcs (VMAT-2A).

Template-based breast IMRT planning for increased workload efficiency.

Background: To be less resource intensive, we developed a template-based breast IMRT technique (TB-IMRT). This study aims to compare resources and dose distribution between TB-IMRT and conventional breast radiation (CBR).

Methods: Twenty patients with early stage breast cancer were planned using CBR and TB-IMRT.

A three-isocenter jagged-junction IMRT approach for craniospinal irradiation without beam edge matching for field junctions.

Purpose: Traditionally craniospinal irradiation treats the central nervous system using two or three adjacent field sets. We propose a technique using a three-isocenter intensity-modulated radiotherapy (IMRT) plan (jagged-junction IMRT) which overcomes problems associated with field junctions and beam edge matching and improves planning and treatment setup efficiencies with homogenous target dose distribution.

Methods And Materials: Treatments for 3 patients with a prescription of 36 Gy in 20 fractions were retrospectively planned with jagged-junction IMRT and compared to conventional treatment plans.

Whole brain radiotherapy with hippocampal avoidance and simultaneous integrated boost for 1-3 brain metastases: a feasibility study using volumetric modulated arc therapy.

Purpose: To evaluate the feasibility of using volumetric modulated arc therapy (VMAT) to deliver whole brain radiotherapy (WBRT) with hippocampal avoidance and a simultaneous integrated boost (SIB) for one to three brain metastases.

Methods And Materials: Ten patients previously treated with stereotactic radiosurgery for one to three brain metastases underwent repeat planning using VMAT. The whole brain prescription dose was 32.

Dosimetric evaluation of Plastic Water Diagnostic-Therapy.

High-precision radiotherapy planning and quality assurance require accurate dosimetric and geometric phantom measurements. Phantom design requires materials with mechanical strength and resilience, and dosimetric properties close to those of water over diagnostic and therapeutic ranges. Plastic Water Diagnostic Therapy (PWDT: CIRS, Norfolk, VA) is a phantom material designed for water equivalence in photon beams from 0.