For vaginal cylinder HDR in the setting of adjuvant endometrial cancer radiation, do you routinely alter the prescription dose based on the diameter of the cylinder?
Or would a typical prescription, such as 7 Gy x 3 Fx to 5 mm depth be reasonable for typical sizes 2.5-3.5 cm? Per ABS guidelines, they specify that the surface dose will vary for varying cylinder sizes and to alter accordingly.
2 Answers
Mednet MemberInvited Expert
Radiation Oncology · University of Texas MD Anderson Cancer Center
Answered on
The prescription dose will remain the same regardless of the size of the cylinder that is used and should be specified to the vaginal surface (often 6 Gy x 5) or to 5 mm depth (often 7 Gy x 3). Because of the inverse square law, the dose to the non-prescription point will vary as a function of cylin...
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Mednet Member
Radiation Oncology · Sunnybrook Health Sciences Centre
Answered on
We keep the prescription dose the same regardless of the cylinder diameter.
7 Gy x 3, weekly treatment.
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