Press Release

PTW Introduces the World's First Liquid-Filled 2D Ion Chamber Array at 2011 Joint AAPM/COMP Meeting

New OCTAVIUS Detector 1000SRS array for stereotactic QA delivers spatial resolution and field coverage similar to film

NEW YORK, NY -- The accurate determination of dose in very small fields poses great challenges for high-precision radiation therapy. With OCTAVIUS Detector 1000SRS, which was developed for the dosimetric verification of very small fields, PTW has now achieved a major breakthrough in SBRT and SRS QA. The new liquid-filled
2D ion chamber array perfectly combines the advantages of ion chambers and solid state detectors, offering a spatial resolution and field coverage as only known from film measurement. It will be on showcase at the Joint AAPM/COMP Meeting in Vancouver, Canada, 31 July - 4 August 2011,  the leading conference for the international medical physics community.

OCTAVIUS Detector 1000SRS is the first commercially available 2D flat-panel detector array worldwide which employs liquid-filled ionization chambers.
Liquid-filled ion chambers show an excellent signal-to-noise ratio even for very small volumes. They are thus capable of providing high spatial resolution which is particularly useful for dose determination in very small radiation fields and high dose gradients as encountered in stereotaxy and radiosurgery. Other than solid state detectors, however, liquid-filled ion chambers have a density very close to water and a superior surface coverage. These particular characteristics put them in the same line with dosimetric films. "OCTAVIUS Detector 1000SRS offers medical physicists the advantages of film dosimetry, but not its known drawbacks - an added workload for calibration, scanning and maintenance. It will make the verification of SBRT and SRS plans much faster and easier than before and truly challenge the use of film in stereotactic quality assurance programs," says John J. Seddo, Managing Director of PTW-New York Corporation.

With 977 liquid-filled ionization chambers, each as small as
2 mm x 2 mm x 0.4 mm, and a spatial resolution of only 2.5 mm, the new OCTAVIUS detector array delivers highly accurate dose measurements for field sizes of less than 1 cm x 1 cm up to
10 cm x 10 cm.
It will be available end of 2011.

For more information on OCTAVIUS, visit PTW at the
AAPM/COMP Meeting, booth # 601
or on the web at

About PTW

In 1922, PTW launched the first dosemeter based on an electrostatic relay which laid the foundation for ionization chamber dosimetry as we know it today. Since then, PTW has successfully built on its reputation as the technology leader for dosimetry applications and is worldwide recognized for its product excellence and innovative strength. As a globally operating company, PTW today provides the full range of dosimetry products and services to healthcare professionals in radiation therapy, diagnostic radiology, nuclear medicine and health physics in more than eighty countries. The private-owned company employs approximately
260 people and keeps in close contact with the international medical physics community through a network of subsidiaries and licensed partners.
For more information on PTW visit

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Press Contact USA:

John J. Seddo
+1 516 827-3181

Press Contact International:

Ute Wuestefeld
+49 761 49055-591

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