Bootstrap Framework 3.3.6

[michael_tallhamer_msc_dabr]

For those of you who use AlignRT for SGRT...

How often are you doing monthly / SRS calibration? Are you following the recommendation of doing it monthly or are you doing it more on an "as needed" basis (meaning when the daily starts to show some sort of drift)?

We started off doing it every month for about the first year which necessitates redoing you SRS calibration as well but we weren't seeing any indication that it was needed. We went to looking at the daily QAs for an indication that the system is drifting and it seems to be very stable. However, I'm not sure that should be the only indicator in going to a longer cycle or an as needed regiment.

We are looking at our daily QA stats and haven't done a monthly for approx 22 months at our primary site and the system remains rock solid. I have other sites that had to do a monthly after approx. 10 months and not had to do one since. We do very extensive pretreatment QAs for our SRS patients (WL, Hidden Target, IsoCal, dose verification) and monthly QA testing the cameras against WL tests with and without imaging and the system is remarkably stable so I'm not worried that we are possibly missing anything systematically but I'm more or less curious at what others are doing and the rationale for doing so.

Thanks,
Mike

[serpil_wilson_ms_dabr]

Hi Mike,

At RockHill Radiation Therapy Center every month I check the calibration to make sure isocenter is not deviated from the previous month or last Monthly QA

We set our morning QA tolerance to 0.5 cm .. As we all know , if they fail daily QA test  3 times, the monthly QA wipes out.  At our site, RTT is well trained to do a monthly qa with a raised plate calibration so that in case physicist is not arrived they can treat patients without any interruption.  However, they notify physics right away to redo the monthly QA and check Isocal during lunch or at the end of that day.  We have been utilizing ART (Align RT) since summer of 2015 and we have never failed  daily QA and RTT never had to do monthly QA in the absence of physicist.

I check Isocal once a month to verify there is no shift. If we have an SRS patient,  I will check the entire system (Mechanical Iso, Imaging Iso and Align RT)  during W-L test. In the morning of the SRS treatment,  I will do a quick check on ODI, and laser and set ART Iso Cube.  I have a QA patient collimators/ MLC's are set for center ball of the IsoCube.   I will acquire  W-L  images  and using the entire cube I will re acquire portal images to check ART  Isocal and verify this set up with Kv pair and CBCT.  There is usually no shifts in images and W-L values are less than 0.5 mm. Real delta values for ART Iso is very close to zero.

Serpil

[serpil_caputlu_wilson]

Tolerance supposed to be 0.5 mm not cm..I hope many caught that typo :))

[james_murray]

Hi Serpil,

I'm new to the forum.  I was not aware that of "<span style="color: #515151; font-family: 'Hind Vadodara', sans-serif; line-height: 1.5;">As we all know , if they fail daily QA test  3 times, the monthly QA wipes out."</span>

Is that really true?

Jim

[serpil_wilson_ms_dabr]

Hi Jim,

We have version 5.0.1747 and installed in mid 2015. Yes, That is true!!!  If Daily Qa does not pass three times , the system does not allow you to repeat the DailyQA and you need redo Monthly QA- I consider this is a very well established safety lock.  We experienced this  only once at early days when our therapists were new to the system.  Now if in case Daily QA fails once, they check their setup, room light etc.. right away.  Please let me know if you have any more questions

serpil

Here  are some inserts from VisionRT training module. 'Phase 1 Module Summary1.2 Final.pptx    page 27-28
<p dir="LTR" align="CENTER">What are two occurrences that force the user to do Monthly Calibration?---</p>
<p dir="LTR">1. Product installation</p>
<p dir="LTR" align="CENTER"></p>
<p dir="LTR">2. Daily QA failed three times</p>

<dir>
<p dir="LTR">------------------------------------------------</p>
<p dir="LTR">DAILYQA</p>
<p dir="LTR">Does <b>NOT</b> define or check isocenter or calibrate the system.</p>
<p dir="LTR">Checks that the current monthly calibration is still valid by comparing data generated from pairs of pods.</p>
<p dir="LTR">The process calculates the 3D blob locations from the Daily QA images.</p>
<p dir="LTR">These locations are compared to their ideal positions and the average shift from true to ideal is computed for each camera pod.</p>
<p dir="LTR">The discrepancy between these shifts are computed between two pairs of pods giving two error values.</p>
<p dir="LTR">If either of the two errors are greater than 1mm the Daily QA fails.</p>
<p dir="LTR">Failure is normally due to relative camera pod movement.</p>
<p dir="LTR">------------------------------------------------------------------------------------------------</p>
<p dir="LTR">Monthly QA</p>

<dir>
<p dir="LTR">Determines the camera locations and parameters</p>
<p dir="LTR">Defines the isocenter position from which all patient shifts are computed</p>

</dir>
<p dir="LTR"></p>
<span style="font-family: Arial;">**</span><span style="font-family: Arial; font-size: x-large;"><span style="font-family: Arial; font-size: x-large;">IF DONE INCORRECTLY ALIGNRT WILL INCORRECTLY PERFORM MATCHING </span></span>

</dir>
<p dir="LTR" align="CENTER"></p>

[serpil_wilson_ms_dabr]

Hi Jim,

We have version 5.0.1747 and installed in mid 2015. Yes, That is true!!!  If Daily Qa does not pass three times , the system does not allow you to repeat the DailyQA and you need redo Monthly QA- I consider this is a very well established safety lock.  We experienced this  only once at early days when our therapists were new to the system.  Now if in case Daily QA fails once, they check their setup, room light etc.. right away.  Please let me know if you have any more questions

serpil

Here  are some inserts from VisionRT training module. 'Phase 1 Module Summary1.2 Final.pptx    page 27-28


<p dir="LTR" align="CENTER">What are two occurrences that force the user to do Monthly Calibration?---</p>

<p dir="LTR">1. Product installation</p>

<p dir="LTR">2. Daily QA failed three times</p>



<p dir="LTR">------------------------------------------------</p>
<p dir="LTR">DAILYQA</p>
<p dir="LTR">Does <b>NOT</b> define or check isocenter or calibrate the system.</p>

<p dir="LTR">Checks that the current monthly calibration is still valid by comparing data generated from pairs of pods.</p>
<p dir="LTR">The process calculates the 3D blob locations from the Daily QA images.</p>
<p dir="LTR">These locations are compared to their ideal positions and the average shift from true to ideal is computed for each camera pod.</p>
<p dir="LTR">The discrepancy between these shifts are computed between two pairs of pods giving two error values.</p>

<p dir="LTR">If either of the two errors are greater than 1mm the Daily QA fails.</p>
<p dir="LTR">Failure is normally due to relative camera pod movement.</p>
<p dir="LTR">------------------------------------------------------------------------------------------------</p>
<p dir="LTR">Monthly QA</p>



<p dir="LTR">Determines the camera locations and parameters</p>
<p dir="LTR">Defines the isocenter position from which all patient shifts are computed</p>

<p dir="LTR"></p>


<span style="font-family: Arial;">**</span><span style="font-family: Arial; font-size: x-large;"><span style="font-family: Arial; font-size: x-large;">IF DONE INCORRECTLY ALIGNRT WILL INCORRECTLY PERFORM MATCHING </span></span>
<p dir="LTR"></p>

<p dir="LTR" align="CENTER"><span style="font-family: Arial;">
</span></p>

[daniel_vetterli]

Hi Serpil

obviously you are using the ART SRS module for ART MV iso calibration. I try to understand what this module is exactly doing... According to the manual there are 2 options to perform the iso calibration, either "image center option" or "field center option". Which one are you using and for what rational? Lets assume you performed ART iso calibration (with one or the other method) and applied the couch shift such that all RTDs are "0.0" at couch angle 0°. Then you rotate your couch e.g. to 270° and you will find some non zero RTDs. How did you validate the correctness of these RTDs at non zero couch angle?

One last question. Do you consider the ART SRS module as an aboslute necessity when applying arcs at non-zero couch angles and you don't have a room based kV-imaging system to cross check patient positioning after couch rotation?

Best regards
Daniel

[ryan_huntley]

Hi Daniel,

In reference to which MV Iso option to use, "Field center" option will calculate centroid of your 10x10 field and use that as radiation isocenter. "Image center" option uses the calibration of your MV imager to establish radiation ISO. VRT trainers instructed that it is up to us to decide, but usually "image center" is used if you have ISOCAL, which is apparently something on TrueBeams. Since we do not have ISOCAL, I am planning on using the "field center" option, but will probably use MLC to define my 10x10, as I trust MLC tolerance more than jaw tolerance.

Hope this helps.

Ryan

[ali_alkaissi]

Has anyone done commissioning on AlignRT before implementing it in the clinic? Beside AAPM TG-147 report, has anyone done any E2E testing with a 4D phantom ? Anyone done any DIBH testing with a phantom ?