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[alissa_fischer]

Hi all,

I am looking into setting breast patients up using the Free Breathing DICOM/then using the Breath hold DICOM for treatment.  I'm curious as to what imaging other centers are using for their DIBH Breast cases.  We typically take Orthogs & film each port on the patients very first day, then switch to taking weekly port films (s/clav & tangents for 4-field patients or just tangs on a breast case with no nodal involvement).  The MD's seem to be pushing for us to take daily orthogs lately, however we find that we typically need to make additional shifts off out tangents.  Bear in mind that all our films are taken with the patients breath held using the DICOM BH surface.  I am interested to find out what other centers are doing/what the work flow is for breast cases using Vision.

[ellen_herron_bsrtt]

We do the same for initial verification and weekly ports. Are you recapturing the FB and BH reference image after shifting on films? When taking orthogs (on lateral) are you looking at spine and sternum to make sure they both are on? If not, you may need to have to patient take in air or let some out. We also try to get the patient to hold their breath exactly in the middle of the coaching bar. Same is true on FB setup (green is not good enough for us...we get those FB translations as tight as we possibly can especially for yaw, pitch and roll.) When we take the extra second or two to do this they usually fall right into the threshold when taking in breath for their BH image.

[ellen_herron_bsrtt]

Alissa, what type of machine do you have?

[marko_laaksomaa]

Hi Alissa

In the first three fractions we check from AP images that rotation of the vertebra (th1-th10) is inside 1 cm and the pitch/BHL measured from LAT image is in SI inside 7 mm and in AP inside 5 mm, this is measured from LAT image as the displacement errors between vertebra th6 and upper part of sternum.  If these criterions are met, matching location is the compromise match between ribs and sternum in SI, ribs in the LAT direction, and sternum in the AP-direction. With this compromise match tangential image accuracy is with at least 90% effectiveness inside 5mm in SI and 4 mm in AP/LAT with AlignRT. Position of the shoulder joint should be inside 8 mm after compromise match, if not, either small  (1-2 mm) shift in the matching location is done towards shoulder joint or arm re-setup is performed. If addition to these SI,LAT,AP isocenter in the orthogonal images are systematically inside 5 mm in the first three fraction, daily tangential AND weekly AP/LAT IGRT- protocol is performed. If the named threshold are exceeded in the three first fractions we continue with the orthogonal images as long as we have solved the problem. This mostly requires new VRT surfaces and changes in the original ROI.

If only AP/LAT images are acquired matching guidelines and protocols in the unit should be in good order to treat blindly the tangential. If only tangential images are acquired, one do not see enough about patient entire chest wall position. Both is better but unpractical. So we try in the first fractions make this AlignRT to discuss with the orthogonal images as reliably as possible and after that make IGRT protocoll lighter.

Best regards Marko

[alissa_fischer]

<span style="font-family: Georgia, serif;">Thanks for all the feedback, this is helpful.  We are using a Varian ix machine.</span>



<span style="font-family: Georgia, serif;">I did forget to mention that every treatment we take one CINE image during one of the tangent fields to make sure Vision is reading the patients surface correctly and that there is no heart in the treatment field (unless planned).  The way we use Vision is a little different in that we only use it to check the patients breath hold and monitor the vertical value in Vision during a patients treatment as we are using the Breath hold DICOM Surface for treatment.    We do not currently set-up patients using Vision- we are in the process of potentially changing the way we use the system.  In fact we only import the DICOM Breath hold surface into Vision and only reacquire a new surface if needed based on our daily CINE images.  We set patient up (free breathing and THEN turn on vision, have patient take breath in and either coach patient to get within vertical threshold or can adjust the couch vertical +/- 3mm in either direction from the couch vertical value noted from Day 1.  (We check the patients Free breathing PIN and DIBH PIN Day 1 and stick with that Couch vertical value throughout treatment unless we start having trouble getting the patient to the correct breath hold)  The way we use it works, but there are times when we have set-up issues and trouble shooting these cases can be cumbersome.  Like I mentioned we do take orthogs and all tx ports day 1.  We do pay attention to the separation between the spine and sternum and this flags us if the patient needs to adjust their breath.  Once in a while we will have trouble with patients slightly arching their back to be able to get to the same breath hold they were taking at the time of the sim, and this trouble shooting can be tedious. </span>