A Phase II trial of brachytherapy alone after lumpectomy for select breast cancer: tumor control and survival outcomes of RTOG 95-17.

Purpose: Radiation Therapy Oncology Group 95-17 is a prospective Phase II cooperative group trial of accelerated partial breast irradiation (APBI) alone using multicatheter brachytherapy after lumpectomy in select early-stage breast cancers. Tumor control and survival outcomes are reported.

Methods And Materials: Eligibility criteria included Stage I/II breast carcinoma confirmed to be <3 cm, unifocal, invasive nonlobular histology with zero to three positive axillary nodes without extracapsular extension.

Design, development, and implementation of the radiological physics center's pelvis and thorax anthropomorphic quality assurance phantoms.

The Radiological Physics Center (RPC) developed two heterogeneous anthropomorphic quality assurance phantoms for use in verifying the accuracy of radiation delivery: one for intensity-modulated radiation therapy (IMRT) to the pelvis and the other for stereotactic body radiation therapy (SBRT) to the thorax. The purpose of this study was to describe the design and development of these two phantoms and to demonstrate the reproducibility of measurements generated with them. The phantoms were built to simulate actual patient anatomy.

Consistency of absorbed dose to water measurements using 21 ion-chamber models following the AAPM TG51 and TG21 calibration protocols.

In 1999, the AAPM introduced a reference dosimetry protocol, known as TG51, based on an absorbed dose standard. This replaced the previous protocol, known as TG21, which was based on an air kerma standard. A significant body of literature has emerged discussing the improved accuracy and robustness of the absorbed dose standard, and quantifying the changes in baseline dosimetry with the introduction of the absorbed dose protocol.

Design and implementation of an anthropomorphic quality assurance phantom for intensity-modulated radiation therapy for the Radiation Therapy Oncology Group.

Purpose: To design, construct, and evaluate an anthropomorphic phantom for evaluation of intensity-modulated radiation therapy (IMRT) dose planning and delivery, for protocols developed by the Radiation Therapy Oncology Group (RTOG) and other cooperative groups.

Methods And Materials: The phantom was constructed from a plastic head-shaped shell and water-equivalent plastics. Internal structures mimic planning target volumes and an organ at risk.

Procedures for establishing and maintaining consistent air-kerma strength standards for low-energy, photon-emitting brachytherapy sources: recommendations of the Calibration Laboratory Accreditation Subcommittee of the American Association of Physicists in Medicine.

Low dose rate brachytherapy is being used extensively for the treatment of prostate cancer. As of September 2003, there are a total of thirteen 125I and seven 103Pd sources that have calibrations from the National Institute of Standards and Technology (NIST) and the Accredited Dosimetry Calibration Laboratories (ADCLs) of the American Association of Physicists in Medicine (AAPM). The dosimetry standards for these sources are traceable to the NIST wide-angle free-air chamber.

Update of AAPM Task Group No. 43 Report: A revised AAPM protocol for brachytherapy dose calculations.

Since publication of the American Association of Physicists in Medicine (AAPM) Task Group No. 43 Report in 1995 (TG-43), both the utilization of permanent source implantation and the number of low-energy interstitial brachytherapy source models commercially available have dramatically increased. In addition, the National Institute of Standards and Technology has introduced a new primary standard of air-kerma strength, and the brachytherapy dosimetry literature has grown substantially, documenting both improved dosimetry methodologies and dosimetric characterization of particular source models.

A reanalysis of the Collaborative Ocular Melanoma Study Medium Tumor Trial eye plaque dosimetry.

Purpose: To recalculate the radiation doses delivered to structures of interest within the eye, i.e., the lens, tumor apex, 5-mm point, optic disk, and macula for patients treated with eye plaque radiotherapy on the Collaborative Ocular Melanoma Study (COMS) Medium Tumor Trial, using updated dosimetric data.

Differences in electron beam dosimetry using two commercial ionization chambers and the TG-21 protocol: another reason to switch to TG-51.

Two of the most popular dosimetry systems used for calibration of megavoltage photon and electron beams in radiation therapy are (i) cylindrical Farmer-type chambers in liquid water and (ii) Holt Memorial parallel-plate chambers in clear polystyrene. Since implementation of the AAPM TG-21 calibration protocol, the Radiological Physics Center (which uses the Farmer in-water system) has compared machine calibrations on two occasions with those of Memorial Sloan-Kettering Cancer Center (which uses the Holt in-polystyrene system). Two years post publication of the TG-51 protocol, 70% of the clinics monitored by the RPC still use TG-21.

Radiotherapy: effects on expanded skin.

Although the combination of radiation and tissue expansion has been associated with a significant rate of complications, the specific pathophysiology has yet to be clearly elucidated. The objective of this study was to develop a model to identify and examine specific histologic changes associated with tissue expansion and irradiation. Rectangular 50-cc silicone tissue expanders were placed subcutaneously over the midline dorsum of 18 adult New Zealand white rabbits.