Preventing wrong site treatment?

[Krukenberg]

---

Members don't see this ad.

Hey,

Spinning this off from the discussion about malpractice cases. Anyone have a systematic way of preventing wrong site treatment?

I was thinking of putting a wire over the intended site before sims. Kind of like how surgeons will initial the correct limb after confirming with the patient.

 

[TheWallnerus]

Hey,

Spinning this off from the discussion about malpractice cases. Anyone have a systematic way of preventing wrong site treatment?

I was thinking of putting a wire over the intended site before sims. Kind of like how surgeons will initial the correct limb after confirming with the patient.

PREPARATION
Pre-tx doesn't worry me as much. I will see 100% of my treated cases in silico before treatment/after sim. If wrong site has been simmed... which is kind of difficult to do (simmed the leg instead of the abdomen, and I can't see any abdomen on the CT)... then you just re-sim. To me, there are two types of wrong site tx: wrong side (R instead of L breast), and wrong site (breast instead of anus). The first one is more common. I don't "wire" every case (i.e. I let the tech place the dye soaked long Q tip for an endometrial case), but I do put the wires on in sim for every breast/CW case. Any skin case, I draw the block area (magic marker on skin) prior to sim. Some cases will just never be amenable to drawing/wiring: whole brain, nasopharynx, prostate, etc.

EXECUTION
IGRT on every single case: palliative, 3D, AP/PA, even go so far as electron (plan the electron in Eclipse e.g. and have dosimetry put on CBCT or kV films on the "iso"). It's the best, most robust way to prevent wrong site tx IMHO. To me it's a little weird that with the plethora of QA activities in radiation oncology there's not been an idea to QA the patient setup prior to every fraction; short of having the physician personally attend every tx fraction, IGRT (with computer automatch) accomplishes that.

 

[seper]

I don’t see how IGRT would help. You’re taking ports before 1st fraction, anyway

 

[TheWallnerus]

I don’t see how IGRT would help. You’re taking ports before 1st fraction, anyway

Fair. Although the MV films are much hazier and usually not as amenable to the computer weighing in (auto match) on the process. I recall a case of a lady with a parotid malignancy in Atlanta treated by an Atlanta rad onc back in the early 2000s. Was in news, can't find now. If not mistaken, she got right parotid (correct side) treated first day but thereafter with a therapist change-over had the wrong side, left, treated for two weeks. Could have been prevented w/ daily IGRT?

 

[RickyScott]

I don’t see how IGRT would help. You’re taking ports before 1st fraction, anyway

had one of the first cone beams in the north east and in the first 3 months, caught 2 failure to shift. Prior to igrt, techs would just make a special effort on port day. Chief tech had some saying about how they can always provide good port films (but who knows what is going on the other days).

Yes, ports are taken first day, but what if you drop the ball. and would have caught error on second or third fraction w/igrt. (No one is going to admit that they just rushed through ports and just signed off without really looking, but it happens) With daily igrt or (surface guidance), hard to deliver wrong treeament. I use igrt or surface guidance for every fraction.

 

[TheWallnerus]

had one of the first cone beams in the north east and in the first 3 months, caught 2 failure to shifts. Prior to igrt, techs would just make a special effort on port day. Chief tech had some saying about how they can always give good port films (but who knows what is going on the other days).

Yes, ports are taken first day, but what if you drop the ball. and would have caught it on the second or third fraction w/igrt. With daily igrt or (surface guidance), hard to deliver wrong treeament. I use igrt or surface guidance for every fraction.

Yeah the shifts can be tricky. You've got marks for the "sim iso," and then there can be a shift to the actual iso on setup day... and that is marked... and sometimes the therapists keep the initial sim iso marks on... well, you know. If the beam is aimed >1cm away from where it should be, that's wrong site, too. How would you know if you weren't IGRTing every day.

 

[jondunn]

Daily IGRT is great.

I do it for everyone, many times not getting it paid for (bone Mets won’t get paid routinely, etc)

 

[Palex80]

EXECUTION
IGRT on every single case: palliative, 3D, AP/PA, even go so far as electron (plan the electron in Eclipse e.g. and have dosimetry put on CBCT or kV films on the "iso"). It's the best, most robust way to prevent wrong site tx IMHO. To me it's a little weird that with the plethora of QA activities in radiation oncology there's not been an idea to QA the patient setup prior to every fraction; short of having the physician personally attend every tx fraction, IGRT (with computer automatch) accomplishes that.

An SGRT system could (in theory) fix that.

 

[RickyScott]

An SGRT system could (in theory) fix that.

It does, and use it all the time.

 

[Krukenberg]

It does, and use it all the time.

So would SGRT tell you if a shift wasn’t performed?

 

[TheWallnerus]

So would SGRT tell you if a shift wasn’t performed?

Yes. If the patient is not aligned to the isocenter as exists in the TPS, it will show as a mismatch w/ SGRT. Other image guidance tech will show if the patient is not aligned to the isocenter too tho (CBCT e.g.). But SGRT does have an advantage of helping the patient (and the therapists) get nearer to the iso quicker than X-ray methods. Then when you CBCT e.g. after SGRT it's going to be finesse work; almost always X, Y, and Z shifts will be <0.7 cm.

And then when you beam on you check that the radiation hits the right spot by monitoring Cherenkov. JK. But it would be cool to have.

 

[seper]

Daily IGRT is great.

I do it for everyone, many times not getting it paid for (bone Mets won’t get paid routinely, etc)

Is your manager good at figuring out when to bill for IGRT and when not to? At my current employer they bill for everything and I'm a bit worried about straight Medicare pts.
Also, when you do non-billable CBCT, do you get wRVU credit anyway?

 

[elementaryschooleconomics]

And then when you beam on you check that the radiation hits the right spot by monitoring Cherenkov. JK. But it would be cool to have.

I really want the Beamsite device. I absolutely cannot figure out a reason to justify it other than "it's cool". I don't think "doc thinks it's cool" is a budget justification though.

 

[jondunn]

Is your manager good at figuring out when to bill for IGRT and when not to? At my current employer they bill for everything and I'm a bit worried about straight Medicare pts.
Also, when you do non-billable CBCT, do you get wRVU credit anyway?

it's a bit of a hurdle. we need to come up with a more systematic way for when to bill and when not to

 

[TheWallnerus]

Is your manager good at figuring out when to bill for IGRT and when not to? At my current employer they bill for everything and I'm a bit worried about straight Medicare pts.
Also, when you do non-billable CBCT, do you get wRVU credit anyway?

it's a bit of a hurdle. we need to come up with a more systematic way for when to bill and when not to

In the hospital the IGRT technical is not billable for IMRT (it's bundled). And no kind of IGRT is billable for SBRT/SRS no matter place of service (bundled as well). When it comes to Medicare it's all about "medical necessity." If you feel that the necessity is there to do IGRT, you do the IGRT. Following some of the medical reasoning in this thread it seems like the medical necessity is often times there. What is problematic w/ Medicare is when you do IGRT, and it is not bundled, and you don't bill for it. This is the boogeyman tale of "down coding" which is often told but doesn't appear to have near the attractiveness to whistle-blowers.

 

[evilbooyaa]

I had a near miss like this once - we simmed both legs, I forgot that patient was FFS rather than HFS, planned for RT along the wrong leg. Caught at machine when patient saw them lining up over his R femur and said his L femur was the one hurting. So wrong side rather than truly wrong site (but it is officially similar).

I think a wire at time of CT sim on the laterality being treated is reasonable.

 

[jondunn]

I had a near miss like this once - we simmed both legs, I forgot that patient was FFS rather than HFS, planned for RT along the wrong leg. Caught at machine when patient saw them lining up over his R femur and said his L femur was the one hurting. So wrong side rather than truly wrong site (but it is officially similar).

I think a wire at time of CT sim on the laterality being treated is reasonable.

This is the danger zone. I have to always remember when I do feet first sim

 

[Krukenberg]

I had a near miss like this once - we simmed both legs, I forgot that patient was FFS rather than HFS, planned for RT along the wrong leg. Caught at machine when patient saw them lining up over his R femur and said his L femur was the one hurting. So wrong side rather than truly wrong site (but it is officially similar).

I think a wire at time of CT sim on the laterality being treated is reasonable.

Scary when it comes that close. Sounds like SGRT would have caught that, but only if the area it’s looking at includes part of the pelvis. If it’s strictly looking at the leg, I’d be concerned that it could get fooled.

 

[Ray D. Ayshun]

I had a near miss like this once - we simmed both legs, I forgot that patient was FFS rather than HFS, planned for RT along the wrong leg. Caught at machine when patient saw them lining up over his R femur and said his L femur was the one hurting. So wrong side rather than truly wrong site (but it is officially similar).

I think a wire at time of CT sim on the laterality being treated is reasonable.

What were you treating in the right femur? I draw a gtv or ctv always, even palliative bone.

 

[medgator]

What were you treating in the right femur? I draw a gtv or ctv always, even palliative bone.

Can't imagine the last time i treated anything without a volume... Even in single fraction HO I'll draw something

 

[evilbooyaa]

What were you treating in the right femur? I draw a gtv or ctv always, even palliative bone.

As do I.
Patient had metastatic disease in bilateral femurs (and most other bones) so had plenty of things in both femurs that could be considered symptomatic. I suppose we were going to treat asymptomatic bone metastases, not the one that was actually bothering him.

 

[Lamount]

I’ve had a patient change their mind about which met was symptomatic on the first day of treatment…. Not technically a near miss, but there was a few minutes where I thought it was.

 

[Burt Radnolds]

Have worked several jobs and in said jobs have worked at multiple sites per job. No less than 4 times across multiple jobs/sites have I seen the CBCT be dead on but the confirmatory ports be off. Turns out you can have a CBCT be perfect and still be wrong. Depending on how iso is assigned in the TPS and in the setup fields, you can be duped into thinking you are aligned but not quite so. Furthering the pain is that therapists can be so lulled to sleep by CBCT infallibility that they don't pick up on these potentially catastrophic misalignments. One patients was a prostate who would have received 80gy into the entire rectum if I hadn't noticed the 1.5cm ant post misalignment. Sleep well!!!

 

[medgator]

Have worked several jobs and in said jobs have worked at multiple sites per job. No less than 4 times across multiple jobs/sites have I seen the CBCT be dead on but the confirmatory ports be off. Turns out you can have a CBCT be perfect and still be wrong. Depending on how iso is assigned in the TPS and in the setup fields, you can be duped into thinking you are aligned but not quite so. Furthering the pain is that therapists can be so lulled to sleep by CBCT infallibility that they don't pick up on these potentially catastrophic misalignments. One patients was a prostate who would have received 80gy into the entire rectum if I hadn't noticed the 1.5cm ant post misalignment. Sleep well!!!

Big fan of kV and fiducials for that reason. Relatively dummie proof compared to daily CBCT if your therapists aren't at the top of their game

 

[TheWallnerus]

Have worked several jobs and in said jobs have worked at multiple sites per job. No less than 4 times across multiple jobs/sites have I seen the CBCT be dead on but the confirmatory ports be off. Turns out you can have a CBCT be perfect and still be wrong. Depending on how iso is assigned in the TPS and in the setup fields, you can be duped into thinking you are aligned but not quite so. Furthering the pain is that therapists can be so lulled to sleep by CBCT infallibility that they don't pick up on these potentially catastrophic misalignments. One patients was a prostate who would have received 80gy into the entire rectum if I hadn't noticed the 1.5cm ant post misalignment. Sleep well!!!

Ruminated on this. I have never seen anything like it so I'm trying to guess at what you mean/what happened. It almost sounds like the dosimetrists are making the CBCT iso not be the same iso as the beams' iso (post IGRT shift by a specified amount?). If so that's a big recipe for disaster.

 

[Lamount]

Ruminated on this. I have never seen anything like it so I'm trying to guess at what you mean/what happened. It almost sounds like the dosimetrists are making the CBCT iso not be the same iso as the beams' iso (post IGRT shift by a specified amount?). If so that's a big recipe for disaster.

Agree. The only times I see this massive shift is either when CBCT cannot be performed at true iso because of clearance issues, or we are doing a stitched CBCT for large (sup/inf) targets. Then it is just a matter of the therapists making sure they shift back to iso.

 

[evilbooyaa]

Have worked several jobs and in said jobs have worked at multiple sites per job. No less than 4 times across multiple jobs/sites have I seen the CBCT be dead on but the confirmatory ports be off. Turns out you can have a CBCT be perfect and still be wrong. Depending on how iso is assigned in the TPS and in the setup fields, you can be duped into thinking you are aligned but not quite so. Furthering the pain is that therapists can be so lulled to sleep by CBCT infallibility that they don't pick up on these potentially catastrophic misalignments. One patients was a prostate who would have received 80gy into the entire rectum if I hadn't noticed the 1.5cm ant post misalignment. Sleep well!!!

Would also be intrigued as to the rationale behind this... just set CBCT iso = kV/kV iso and the only thing that causes that is a huge gas bubble in the rectum, after the CBCT, before the kVs.

 

[Burt Radnolds]

Would also be intrigued as to the rationale behind this... just set CBCT iso = kV/kV iso and the only thing that causes that is a huge gas bubble in the rectum, after the CBCT, before the kVs.

Yes this is clearly the ideal way of doing it. Just saying that it is possible for iso defined on CBCT to be different than the plan iso (this should never actually be the case, but it is in fact possible). For an MV or kV port, iso is iso is iso, you can't trick the system otherwise. But for a CBCT, you could theoretically think you were aligned, but if someone input the CBCT with a different iso than plan you might not be. Theoretically this should all be easily picked up by physics/dosimetry ahead of time in chart check, or even the therapists reviewing the setup or in room SSDs. And perhaps it even would require an unadvised console override to get to this point too, that would be a question for someone else.

Think about it this way. You are treating someone with sequential IMRT plans, without plans to resimulate. There is an iso shift for the boost. However, when the patient is getting the boost, the therapist loads up the initial CBCT somehow from the first plan instead of the new iso shifted one and all looks good. There are many ways this should be detected though before and during the process.

 

[Palex80]

Ruminated on this. I have never seen anything like it so I'm trying to guess at what you mean/what happened. It almost sounds like the dosimetrists are making the CBCT iso not be the same iso as the beams' iso (post IGRT shift by a specified amount?). If so that's a big recipe for disaster.

Indeed. I am aware of a handful of cases we did this and it could have gone wrong, had we not shifted back.

I remember a patient getting treatment of both breasts, including IMN and SCV where the plan ISO was in the middle but we performed separate CBCTs to be certain that the breast contours matched. That could have gone wrong.

I also recall a patient receiving CSI where we did an extra CBCT at the junction of the fields to be certain there is no overlap, then shifted back to ISO.

But these are REALLY special cases and certainly not your everyday patients!

 

[TheWallnerus]

Yes this is clearly the ideal way of doing it. Just saying that it is possible for iso defined on CBCT to be different than the plan iso (this should never actually be the case, but it is in fact possible). For an MV or kV port, iso is iso is iso, you can't trick the system otherwise. But for a CBCT, you could theoretically think you were aligned, but if someone input the CBCT with a different iso than plan you might not be. Theoretically this should all be easily picked up by physics/dosimetry ahead of time in chart check, or even the therapists reviewing the setup or in room SSDs. And perhaps it even would require an unadvised console override to get to this point too, that would be a question for someone else.

Think about it this way. You are treating someone with sequential IMRT plans, without plans to resimulate. There is an iso shift for the boost. However, when the patient is getting the boost, the therapist loads up the initial CBCT somehow from the first plan instead of the new iso shifted one and all looks good. There are many ways this should be detected though before and during the process.

Indeed. I am aware of a handful of cases we did this and it could have gone wrong, had we not shifted back.

I remember a patient getting treatment of both breasts, including IMN and SCV where the plan ISO was in the middle but we performed separate CBCTs to be certain that the breast contours matched. That could have gone wrong.

I also recall a patient receiving CSI where we did an extra CBCT at the junction of the fields to be certain there is no overlap, then shifted back to ISO.

But these are REALLY special cases and certainly not your everyday patients!

If there is ever a call for a separate IGRT and plan/beam iso, my policy is to make a whole separate plan for the IGRT iso, with one 1x1cm AP beam that delivers 1 MU per fraction. This plan is labelled "SETUP PLAN" in the TPS. (And even if it is accidentally administered it can only give one 1x1cm field of 1 cGy in a single fraction.) Then the therapists must mode up a whole other plan, the "TREATMENT PLAN," in the system after the setup iso is obtained, and a pre-specified shift to the setup plan (i.e. "shift patient 10 cm in and 10 cm left") is documented copiously in the thin paper chart and R&V system. (I feel it's good practice to make the "SETUP PLAN" iso some round, whole integer number offset from the "TREATMENT PLAN" iso; "shift patient 3.78 cm out and 5.92 cm right" would be no bueno in my dept.)

In short, I never allow but one iso in any plan.

 

[Burt Radnolds]

If there is ever a call for a separate IGRT and plan/beam iso, my policy is to make a whole separate plan for the IGRT iso, with one 1x1cm AP beam that delivers 1 MU per fraction. This plan is labelled "SETUP PLAN" in the TPS. (And even if it is accidentally administered it can only give one 1x1cm field of 1 cGy in a single fraction.) Then the therapists must mode up a whole other plan, the "TREATMENT PLAN," in the system after the setup iso is obtained, and a pre-specified shift to the setup plan (i.e. "shift patient 10 cm in and 10 cm left") is documented copiously in the thin paper chart and R&V system. (I feel it's good practice to make the "SETUP PLAN" iso some round, whole integer number offset from the "TREATMENT PLAN" iso; "shift patient 3.78 cm out and 5.92 cm right" would be no bueno in my dept.)

In short, I never allow but one iso in any plan.

There are many things that can/should be done to avoid any iso funny business. Any difference between cbct iso and treatment iso should be methodically planned out such as your methods. The few times that I can recall that something was amiss, everyone knew it and it was just trying to figure out why. However there was that one aforementioned time we were off ant - post and I was sadly the last line of defense. There had just been a massive restructuring of physics/dosimetry at this particular place the week prior to give you some insight. I tell the story as I feel it is educational for some who don't understand some of the underlying principles and a reminder to always be vigilant. Ultimately I ended up doing a lot of my own dosimetry stemming from early experience with a weak team. Thankfully I have great support now but still am more hands on than most (except you).

 

[evilbooyaa]

There are many things that can/should be done to avoid any iso funny business. Any difference between cbct iso and treatment iso should be methodically planned out such as your methods. The few times that I can recall that something was amiss, everyone knew it and it was just trying to figure out why. However there was that one aforementioned time we were off ant - post and I was sadly the last line of defense. There had just been a massive restructuring of physics/dosimetry at this particular place the week prior to give you some insight. I tell the story as I feel it is educational for some who don't understand some of the underlying principles and a reminder to always be vigilant. Ultimately I ended up doing a lot of my own dosimetry stemming from early experience with a weak team. Thankfully I have great support now but still am more hands on than most (except you).

Thanks for sharing your experiences. I think there is great value in having these discussions, and brainstorming ways to minimize those chances - almost like a Root Cause Analysis on the internet. There are a lot of things like this that we are not necessarily spoon fed in residency, that in residency we "trust" other departments like dosimetry/physics to do their jobs, when in the real world there is a lot of extra supervision from the physician that is necessary.

 

[seper]

Have worked several jobs and in said jobs have worked at multiple sites per job. No less than 4 times across multiple jobs/sites have I seen the CBCT be dead on but the confirmatory ports be off. Turns out you can have a CBCT be perfect and still be wrong. Depending on how iso is assigned in the TPS and in the setup fields, you can be duped into thinking you are aligned but not quite so. Furthering the pain is that therapists can be so lulled to sleep by CBCT infallibility that they don't pick up on these potentially catastrophic misalignments. One patients was a prostate who would have received 80gy into the entire rectum if I hadn't noticed the 1.5cm ant post misalignment. Sleep well!!!

Pictures, or this hasn't happened. Sorry

 

[Krukenberg]

Pictures, or this hasn't happened. Sorry

So our clinic usually starts off by aligning to bone with kv-kv, then does the CBCT for soft tissue adjustment. You’re saying it should actually be the reverse (except maybe with MV)?

 

[TheWallnerus]

So our clinic usually starts off by aligning to bone with kv-kv, then does the CBCT for soft tissue adjustment. You’re saying it should actually be the reverse (except maybe with MV)?

Either way a big problem will or should show. Because either way/order, there will be a big shift to get from one match to the other. The therapists would hopefully realize something amiss. I am also not 100% certain the kV and MVs can’t have different isos from at least some beams with Eclipse new beam iso grouping feature that came out a few years back. Different beams can have different isos in the same plan. I always thought that was a risky feature.