Dosimetric comparison of pre-planned and or-planned prostate seed brachytherapy.
OBJECTIVE
To compare the dosimetry of the traditional two step procedure (volume study + treatment planning several weeks later) with that of an OR-based single procedure in which these two steps follow one another immediately. Computer generated treatment plans were used in both procedures.


METHODS
Several dosimetric parameters relating to target coverage were obtained from dose volume histograms of CT-based evaluation plans developed either 1 or 3 days following seed implantation. A total of 113 patients with early stage (T1C, T2A) prostate cancer were used for this retrospective study.


RESULTS
The fraction of target (prostate) covered by the prescription dose (144 Gy), 90% of the prescription dose (115 Gy), and the dose encompassing 90% of the target in the evaluation plan were all statistically significantly improved for OR-based plans compared to pre-planned cases.


CONCLUSIONS
In our hands, there is a small but significant improvement in dose coverage of the prostate when the ultrasound volume study and treatment planning are combined into a single procedure.
Wilkinson
D A
DA
Department of Radiation Oncology, The Cleveland Clinic Foundation, Cleveland, OH 44195, USA. wilkinson@radonc.ccf.org
Lee
E J
EJ
Ciezki
J P
JP
Mohan
D S
DS
Zippe
C
C
Angermeier
K
K
Ulchaker
J
J
Klein
E A
EA
Mohan
D
D
D001918:Brachytherapy / Q000379:methods*; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D018579:Patient Selection; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography
D007457:Iodine Radioisotopes