EDGE Detector

EDGE Detector

The Ultimate Small Field Dosimeter

EDGE Detector is a waterproof dosimeter with a design that nearly eliminates the convolution of high dose gradient regions during profile and depth measurements. It is intended for measurement of fields as small as 5 mm up to 10 x 10 cm.

Features & Benefits

  • Waterproof
  • Use for SRS and IMRT beam modeling, and TPS Commissioning
  • SunPoint® Diode Detector technology
    • 800 times smaller than micro ionization chambers
    • 100 times more signal than micro ionization chambers
  • Small size ideal for accurate penumbra characterization and steep gradients
  • Works with all common water phantoms
S3 Combined Charts

Output factors measured for CyberKnife® beams at Dmax (6 MV)1

S4 Output Cyberknife Resized

The EDGE Detector agrees with EBT film; even for the 5 mm cone. The ion chambers clearly underestimate the output factors of the small beams.

PDD curves measured by different detectors for a 2 x 2 cm field (6 MV)1

S4 Curves Detectors Resized

The PDD curve measured by EDGE Detector agrees with those of the ion chambers.

EDGE Penumbra Comparison2

Field Size Energy Penumbra measured (mm) at 10 cm depth
(cm x cm)
2 x 2
18 4.4 4.9
10 x 10 6 4.4 5.6
18 5.5 6.9

EDGE Specification Comparison

Detector type SunPoint® Diode Detecto Typical scanning ion chamber
Width (mm): 0.8 2.0
Thickness (mm): 0.03 2.0
Length (mm): 0.8 5.0
Volume (mm3): 0.019 16.0


S7  Features Edgedetector
  1. “Sun Nuclear EDGE Detector Users Guide” pg. 23 - Mr. Daljit Saini and Mr. Anand Prabhu from CCC of Brevard, Melbourne, FL.; Dr. Ellen Wilcox at St. Francis Hospital, Hartford, CT.
  2. “Sun Nuclear EDGE Detector Users Guide” pg. 25 - courtesy of Ron Watts Ph. D.

PinPoint is a registered trademark of PTW Freiburg GmbH, IBA CC01 is a trademark of IBA Dosimetry Corporation. Exradin is a trademark of Standard Imaging Inc.


Active Detection Area (mm): 0.8 x 0.8
0.3 from top
4.72 from end
Diode Die Location: (mm): 2.7 from side Location is indicated by
cross hairs on top of the housing
Water Depth Equivalent (mm): 0.5
Housing Wall Thickness (mm): 0.13 brass
External Dimensions (mm): 3.8 x 5.5 x 38
Nominal Sensitivity (nC/Gy): 32.0
Impedance (Mohm): >200 at 10 mV reverse bias/td>
Output Polarity: Negative
Cable 3.4 mm dia. x 1.8 m long, triax
Cable Connector: BNC or TNC triax, or adapters upon request
S8  Sun Point Logo