Studies - 03-09-2010 01:07 AM
I'm sure most of us never read half the forms we have signed at our Cancer Centers and now-a-days these are all electronic and I really don't think I got copies.
Anyway most of us have unknowingly signed up to be part of numerous studies. I came across another one recently so the other day when I was up at the Cancer Center I asked if I was part of it and sure enough.
One of the doctors mentioned is my RO (Kelly Dewit). She is one of the Brain, Head & Neck RO's,
TEXT of STUDY
Med Dosim. 2010 Spring;35(1):31-7. Epub 2009 Feb 28.
Analysis of daily setup variation with tomotherapy megavoltage computed tomography.
Zhou J, Uhl B, Dewit K, Young M, Taylor B, Fei DY, Lo YC.
Center for Cancer Treatment, Sharp Grossmont La Mesa, CA, USA.
The purpose of this study was to evaluate different setup uncertainties for various anatomic sites with TomoTherapy pretreatment megavoltage computed tomography (MVCT) and to provide optimal margin guidelines for these anatomic sites. Ninety-two patients with tumors in head and neck (HN), brain, lung, abdominal, or prostate regions were included in the study. MVCT was used to verify patient position and tumor target localization before each treatment. With the anatomy registration tool, MVCT provided real-time tumor shift coordinates relative to the positions where the simulation CT was performed. Thermoplastic facemasks were used for HN and brain treatments. Vac-Lok cushions were used to immobilize the lower extremities up to the thighs for prostate patients. No respiration suppression was administered for lung and abdomen patients. The interfractional setup variations were recorded and corrected before treatment. The mean interfractional setup error was the smallest for HN among the 5 sites analyzed. The average 3D displacement in lateral, longitudinal, and vertical directions for the 5 sites ranged from 2.2-7.7 mm for HN and lung, respectively. The largest movement in the lung was 2.0 cm in the longitudinal direction, with a mean error of 6.0 mm and standard deviation of 4.8 mm. The mean interfractional rotation variation was small and ranged from 0.2-0.5 degrees, with the standard deviation ranging from 0.7-0.9 degrees. Internal organ displacement was also investigated with a posttreatment MVCT scan for HN, lung, abdomen, and prostate patients. The maximum 3D intrafractional displacement across all sites was less than 4.5 mm. The interfractional systematic errors and random errors were analyzed and the suggested margins for HN, brain, prostate, abdomen, and lung in the lateral, longitudinal, and vertical directions were between 4.2 and 8.2 mm, 5.0 mm and 12.0 mm, and 1.5 mm and 6.8 mm, respectively. We suggest that TomoTherapy pretreatment MVCT can be used to improve the accuracy of patient positioning and reduce tumor margin. Published by Elsevier Inc.
PMID: 19931012 [PubMed - in process]
Anyway most of us have unknowingly signed up to be part of numerous studies. I came across another one recently so the other day when I was up at the Cancer Center I asked if I was part of it and sure enough.
One of the doctors mentioned is my RO (Kelly Dewit). She is one of the Brain, Head & Neck RO's,
TEXT of STUDY
Med Dosim. 2010 Spring;35(1):31-7. Epub 2009 Feb 28.
Analysis of daily setup variation with tomotherapy megavoltage computed tomography.
Zhou J, Uhl B, Dewit K, Young M, Taylor B, Fei DY, Lo YC.
Center for Cancer Treatment, Sharp Grossmont La Mesa, CA, USA.
The purpose of this study was to evaluate different setup uncertainties for various anatomic sites with TomoTherapy pretreatment megavoltage computed tomography (MVCT) and to provide optimal margin guidelines for these anatomic sites. Ninety-two patients with tumors in head and neck (HN), brain, lung, abdominal, or prostate regions were included in the study. MVCT was used to verify patient position and tumor target localization before each treatment. With the anatomy registration tool, MVCT provided real-time tumor shift coordinates relative to the positions where the simulation CT was performed. Thermoplastic facemasks were used for HN and brain treatments. Vac-Lok cushions were used to immobilize the lower extremities up to the thighs for prostate patients. No respiration suppression was administered for lung and abdomen patients. The interfractional setup variations were recorded and corrected before treatment. The mean interfractional setup error was the smallest for HN among the 5 sites analyzed. The average 3D displacement in lateral, longitudinal, and vertical directions for the 5 sites ranged from 2.2-7.7 mm for HN and lung, respectively. The largest movement in the lung was 2.0 cm in the longitudinal direction, with a mean error of 6.0 mm and standard deviation of 4.8 mm. The mean interfractional rotation variation was small and ranged from 0.2-0.5 degrees, with the standard deviation ranging from 0.7-0.9 degrees. Internal organ displacement was also investigated with a posttreatment MVCT scan for HN, lung, abdomen, and prostate patients. The maximum 3D intrafractional displacement across all sites was less than 4.5 mm. The interfractional systematic errors and random errors were analyzed and the suggested margins for HN, brain, prostate, abdomen, and lung in the lateral, longitudinal, and vertical directions were between 4.2 and 8.2 mm, 5.0 mm and 12.0 mm, and 1.5 mm and 6.8 mm, respectively. We suggest that TomoTherapy pretreatment MVCT can be used to improve the accuracy of patient positioning and reduce tumor margin. Published by Elsevier Inc.
PMID: 19931012 [PubMed - in process]