Four-field breast and genearl breast ca questions

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BraggPeak

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Just thought I would see what other people are doing for four-field breast plans (it's always surprising to me how different it can be from attending-attending and institution-institution):

What do you aim for your ipsilateral V20 to be (we use <20% for 4-field and <15% for regular tangents)

How "hot" are you willing to have the match-line be (120%? 125%?, etc)

If you are doing post-mastectomy XRT with a tissue expander, do you still use bolus? Do you do you do every day until skin rxn, or every other day? Also, do you use 0.5 cm or 1.0 cm bolus?

For your breast-only plans, for patients with large breasts, how low of an isodose line are you willing to prescribe? I've seen some go as low as 86%...but I've also heard other institutions saying they dont like to be more than 7% hot. I mentioned this to my dosimetrists and they laughed at me...
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Our "goal" ipsilateral lung V20 is < 10% for tangents & < 15% for three field. I don't routinely use PAB fields.

Since the isocentric match line is in lung, I think the dose overlap is irrelevant as long as V20 goals are met. The lung has parallel FSUs.

I do not use bolus with tissue expanders s/p mastectomy unless an area of the skin is specifically at risk. Otherwise using bolus increases the risk of capsular contracture IMO. Otherwise I use qod 0.5 cm bolus for regular post-mastectomy XRT.

107% max point dose is a good guideline. For women with very pendulous breast if "substantial" volumes exceed 110% then I will use IMRT.
 
Interesting, when we do our 4-fields, most of the V20s are between 15-20%. I haven't seen any patient with pneumonitis as yet....

We use segments and rarely use IMRT for patients with pendulous breasts (unless it's left-sided, which case we can get IMRT approved more easily from insurance). Do you easily get approval for IMRT for patients who have pendulous breasts?

Is there good data showing that bolus with the expander increases the risk of capsular contracture?

Also, re: match line-- I know it's somewhat irrelevant, but I was just surprised when I saw how hot it gets...
 
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I agree V20s are mostly academic with breast cancer. I've yet to see radiation pneumonitis as an attending for a breast cancer patient.

If you make a good faith effort to do 3D tangents but are unable to achieve reasonable dose homogeneity, I've found most insurers are reasonable in allowing IMRT. If they refuse authorization, we use "forward planned" IMRT.

There is no good data on bolus since its use is so heterogeneous among practices. However, not surprisingly, bolus increases acute skin toxicity. Thus, I don't automatically use it with expanders.
 
Skin is target in PMRT, so I do same bolus as I do with non expanded patients- 0.5cm QOD. I'll break when they peel.

I've seen pneumonitis after SCV RT. Sucks. V20<20 ideal but not always attainable. A late acute pneumonitis may be preferable to a recurrence. Not being sarcastic, but that is my bias. If you actually contour level III and SCV as a target, you may find your V20 higher than when you use a standard bony anatomy field. Not always, but sometimes. Just warn them ahead of time.

As far as capsular contracture/late toxicity - your marginal toxicity with chest wall RT vs Chest wall RT + bolus or scar boost ... Minimal at best. 50 Gy is bad. Question should be to radiate or not radiate, not these minimal questions about bolus and boost. Damage is done. Pick a philosophy beforehand and stick with it. I've basically decided, if under 50, boost regardless. If over 50, boost if without reconstruction. If neither, discuss with patient.

S
 
Keeping lung dose as low as possible is important with regard to secondary malignancies.Obviously, no solid dose-response data are available.
 
Agree with SimulD regarding bolus. Locoregional failure after mastectomy + axillary node dx, regardless of expander placement, is 60-70% chest wall/skin, 25% SCV, 5-10% Axilla, and <2% IMN (NSABP, ECOG, MDACC, etc). As such, skin is important target, perhaps more important than all regional nodes combined. I use 5mm bolus for first 15-18fx (30-36Gy). For pts with tissue expanders in, will often use wet towel bolus due to difficulties with using slab bolus over curved surface.

Capsular contracture is more of an issue for patients having immediate reconstruction. Patients treated with tissue expanders are having delayed-immediate reconstruction. In this setting, bolus use should have minimal effect on risk of contracture.

Agree that pneumonitis is rare in breast cancer tx. Does appear to be increased, however, among patients receiving adjuvant taxane chemo. Agree with Simul that ipsilateral lung V20 tends to be higher with 3D planning than with conventional. I also contour SCV and undissected level III axilla and do 3D planning. Will accept ipsilateral lung V20 up to 25% for chest wall + SCV and up to 32% for comprehensive nodal tx. There are older data from Duke and Scandanavia showing low rate of RP for patients receiving comprehensive nodal RT with ipsilateral lung V20 <32%.

For intact breast, the 7% max dose comes from the Whelan hypofrac study. That was the max allowable dose at central axis. For most patients, however, the max dose is not at central axis. For patients treated with Canadian fractionation, I try to keep point max <110%. In many patients, it is difficult to acheive good target coverage with max constraint of 107%. For patients with larger breast vol or greater separation, treated with conventional fractionation, I keep point max <112%.
 
As far as dose homogeneity, utilizing 3D-FiF with control points, try for maximal point dose of 108% for regular breast, 107% for hypofx (I know - sort of arbritrary) if possible. Will tolerate 110% in either case before trying inverse planning. I also look at volume of 105%. PTV is essentially the 85-90% isodose line turned into a region of interest. I don't carve out lung, but I eyeball it and try to keep the 105% below 15% if possible. Beriwal told me that, but I don't know the actual data.
 
TarHeelRadOnc said:
Agree with SimulD regarding bolus. Locoregional failure after mastectomy + axillary node dx, regardless of expander placement, is 60-70% chest wall/skin, 25% SCV, 5-10% Axilla, and <2% IMN (NSABP, ECOG, MDACC, etc). As such, skin is important target, perhaps more important than all regional nodes combined. I use 5mm bolus for first 15-18fx (30-36Gy). For pts with tissue expanders in, will often use wet towel bolus due to difficulties with using slab bolus over curved surface.

Capsular contracture is more of an issue for patients having immediate reconstruction. Patients treated with tissue expanders are having delayed-immediate reconstruction. In this setting, bolus use should have minimal effect on risk of contracture.

Agree that pneumonitis is rare in breast cancer tx. Does appear to be increased, however, among patients receiving adjuvant taxane chemo. Agree with Simul that ipsilateral lung V20 tends to be higher with 3D planning than with conventional. I also contour SCV and undissected level III axilla and do 3D planning. Will accept ipsilateral lung V20 up to 25% for chest wall + SCV and up to 32% for comprehensive nodal tx. There are older data from Duke and Scandanavia showing low rate of RP for patients receiving comprehensive nodal RT with ipsilateral lung V20 <32%.
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Agree with all of this, especially bolded. It's hard to get a low V20 with a with a 3 or 4-field 3DCRT plan. IMRT doesn't help when we've tried.

Old school folks will just treat the SCV field with a 3 cm calc point, which often underdoses the area where the lymphatics tend to be (especially in modern times, with our more bariatric population). This, unsurprisingly, probably leads to a lower V20 as well.
 
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medgator said:
Old school folks will just treat the SCV field with a 3 cm calc point, which often underdoses the area with the lymphatics tend to me (especially in modern times, with our more bariatric population). This, unsurprisingly, probably leads to a lower V20 as well.
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Since most data we have on SCV recurrence are based on "old school" techniques, perhaps we should re-examine if we don't need the full 50 Gy for subclinical disease or 40-45 Gy would suffice, doses that were given in the past with an anterior field and 3 cm calc point.
 
That's a good point, 45 Gy in 2D era, might be 39-40 Gy in modern era. I'm going to look at some of my plans and compare ...

EDIT: just looked at one prescribed to 3cm. About 10% of the volume got 45 Gy. Most of it get 20-30 Gy. Hmmm...
 
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Palex80 said:
Since most data we have on SCV recurrence are based on "old school" techniques, perhaps we should re-examine if we don't need the full 50 Gy for subclinical disease or 40-45 Gy would suffice, doses that were given in the past with an anterior field and 3 cm calc point.
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Excellent point. Applies to many sites actually. If I'm not mistaken, in the "old school" days, most prescriptions were to isocenter and/or other points. Now, in the era of ct-planning and IMRT, we are Rxing to isodose lines which is basically a built-in dose escalation. Even for the whole breast, if I'm not mistaken, the rx used to be to a point, not an isodose line, so the whole breast never really received 50 Gy. I know attendings who still rx to a point 2/3 the distance from the apex of the breast to the chest wall and simply ensure 90% coverage of the breast. I believe these were the techniques used for the original NSABP trials as well, no?
 
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Amongst other reasons, this partly explains why IBTRs are in the single percent range after RT now.
Same with prostate dose escalation- the Dutch trial, Harvard trial, MDACC all prescribed to a point, while we are giving 75.6-80 Gy to the entire PTV - the biochemical control rates from this single institution reports are all in the mid 90s for low risk. Head and neck must benefit, too - that's why the IMRT protocols like 0022 and 0225 for NP and OP have such low local recurrence rates compared to historical controls. Sometimes the high tech stuff actually improves outcomes. I bet even with palliation - when we did 20 Gy to mid plane in 5 fractions, who knew how much the met got.

S
 
SimulD said:
Amongst other reasons, this partly explains why IBTRs are in the single percent range after RT now.
Same with prostate dose escalation- the Dutch trial, Harvard trial, MDACC all prescribed to a point, while we are giving 75.6-80 Gy to the entire PTV - the biochemical control rates from this single institution reports are all in the mid 90s for low risk. Head and neck must benefit, too - that's why the IMRT protocols like 0022 and 0225 for NP and OP have such low local recurrence rates compared to historical controls. Sometimes the high tech stuff actually improves outcomes. I bet even with palliation - when we did 20 Gy to mid plane in 5 fractions, who knew how much the met got.

S
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Just to play a little devil's advocate here :)... IBTR didn't break 10% until the 20 year followup on NASBP 06 if I'm not mistaken and there was no tamoxifen. Regarding the prostate dosing, the biochemical control on the Harvard trial was >90% for low risk disease in the most recent followup. 0022 was early oropharyngeal cancer (enrollment criteria: T1-2N0-1) in the era of HPV+ disease. Regarding 0225, is it really the dose escalation or is it better definition of target volume (MRI-based volumes) and the use of IMRT that's leading to better control?
 
No - I agree, but I wasn't articulate. The volume based dosimetry is in its own way dose escalation, but it also ensures that the volume you want to treat gets full dose. B06- we've improved because of Tam, the boost, using greater than 1 cell thick margins, effective chemo, but also dose coverage. Same with 0225 - the targets are well defined AND we can give 70 Gy without decreasing coverage. Prostate - well, we have the same control rates and 1-5% grade 2 rectal bleeding. So, yeah I agree - I'm just saying that our technology has allowed us to treat volumes to the dose we want to treat, and we are seeing some better outcomes.
 
When you're looking at breast plans, what is the lowest isodose line you typically look at to make sure there is no low dose creeping to the contralateral breast?
 
Revisiting this excellent thread on breast cancer planning!

Just a few questions:

1. What is the max hot spot you would accept on a IMRT intact breast plan?

2. Taking into account patterns of spread... When do you guys typically add a SCLV field for:
a.)PMRT
b) intact breast (breast conservation)?
c) are there instances of PMRT in which SCLV can be omitted?

Thanks,
B.
 
1. < 0.01 cc receives 110% of Rx dose. Even this is sometimes not possible in patients with a large separation. At that point it is ALARA but options include: covering a little bit less breast (well away from the resection cavity) or reducing the whole breast dose to ~ 44-46 Gy and increasing the boost to compensate.
2. SCV field is added for various reasons: >3 LN positive, cN prior to neo-adjuvant chemotherapy, women with extremely high-risk features (< 35 years old, triple negative, grade III, extensive LVI). There are rare cases that I would perform PMRT without an SCV field such as very close margins on mastectomy but o/w low risk for LN spread
 
Totally agree with point 1. Do both frequently in large breasted pts. Literally took me months, though, to convince my planners maybe it's okay to cheat a few slices on superior breast border when the pt has say a small tumor in the inframammary fold.
 
jcradonc said:
http://www.npr.org/blogs/health/201...w-to-adopt-changes-in-breast-cancer-treatment

thoughts?
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Remember, the calgb study was a prospective randomized study where adherence to adjuvant hormonal manipulation for five years was likely much higher than the community. On top of that, a benefit was in fact shown for the XRT+Tamoxifen arm, it's just that the magnitude of that benefit wrt the expense, hassle and toxicity of XRT was controversial.

http://www.ncbi.nlm.nih.gov/m/pubmed/16541307/

That certainly plays into my discussion with patients. It's not a mandate per the NCCN to omit... You "may omit" xrt in those patients
 
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I agree with medgator that this is a controversial area. NCCN guidelines state "may omit" in this select group of patients. So I explain to patients who would be eligible for Hughes that their risk of breast cancer recurrence in the breast or immediate area (i.e. LNs) is about 10% without radiation and 2% with radiation at 10 years (slight simplification). Most patients I explain that to elect for radiation. My experience with patients is that they will take any little bit of added measure that their breast cancer won't come back, provided the treatment is easy and with minimal side effects. We do mostly 3D-APBI or intra-op for these patients.

Thus, I think the title of the NPR article "doctors are slow to adopt changes" is misleading. My experience is that patient attitudes are driving these practices.
 
Neuronix said:
I agree with medgator that this is a controversial area. NCCN guidelines state "may omit" in this select group of patients. So I explain to patients who would be eligible for Hughes that their risk of breast cancer recurrence in the breast or immediate area (i.e. LNs) is about 10% without radiation and 2% with radiation at 10 years (slight simplification). Most patients I explain that to elect for radiation. My experience with patients is that they will take any little bit of added measure that their breast cancer won't come back, provided the treatment is easy and with minimal side effects. We do mostly 3D-APBI or intra-op for these patients.

Thus, I think the title of the NPR article "doctors are slow to adopt changes" is misleading. My experience is that patient attitudes are driving these practices.
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What's your experience been with 3D-APBI? I'm a bit hesitant to consider that APBI technique vs intra-luminal multi-catheter, or just hypoFx to the whole breast, given the relative lack of data and some data suggesting poorer cosmesis..
 
what's your prescription for 3D-APBI nowadays?
 
medgator said:
What's your experience been with 3D-APBI? I'm a bit hesitant to consider that APBI technique vs intra-luminal multi-catheter, or just hypoFx to the whole breast, given the relative lack of data and some data suggesting poorer cosmesis..
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This is our institution's experience with cosmetic outcomes: http://www.practicalradonc.org/article/S1879-8500(13)00278-6/abstract

The failure rate is incredibly low with limited follow-up. I'd estimate less than 2%. I don't really have long-term outcomes, but we use ASTRO consensus guidelines for APBI to select patients, so the expected failure rate would be low even without treatment. We use the suitable criteria with only one "cautionary" criterion allowed (with the exception of using grade 3 as a cautionary as well which is not included in the guidlines).

Since we do both 3D-APBI and IORT, I'm in the process of trying to comparing cosmetic outcomes between the two. We had an abstract on this recently that I'd like to turn into a manuscript at some point: http://www.redjournal.org/article/S0360-3016(13)01223-6/fulltext

My take on it is that we're not the first to report that the V50% (volume of whole breast receiving 50% (19.25 Gy) or more of the prescription dose) is correlated with poor cosmetic outcomes. So smaller breasted women here should probably be getting IORT assuming their cavity is far enough away from the skin surface. IORT's issue is that it tends to leave a large seroma, though these are mostly asymptomatic (http://onlinelibrary.wiley.com/doi/10.1002/jso.23581/full).

How this all compares to the many other partial breast techniques, I really couldn't say. Our median age in the cosmetic outcomes series was 69, and honestly I'm yet to meet a woman in her 60s or older who really cares much about breast cosmesis.

I do think the START trial and Canadian hypofx trials for whole breast are also very reasonable alternatives even in this low risk patient population. They're just not as fast of course.

seper said:
what's your prescription for 3D-APBI nowadays?
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3.85 Gy BID x 5 days per NSABP B39 protocol (summary and nice pictures: http://atc.wustl.edu/protocols/nsabp/b-39/PBI_presentations_050122/PDF/PBI_Arthur.pdf)
 
seper said:
This regimen is now known to be unsafe (Olivotto et al). I put a lot of patients on RTOG 0413 during my training, and we've known that all along.
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Oh, RAPID trial. I was unclear from your post what was "unsafe" about the technique. I do take issue with the word "unsafe" because that to me implies cardiac, pulmonary, or some other toxicity beyond cosmesis.

Sure, the publication showed that cosmesis is worse with 3D-APBI than whole breast. Given the five retrospective series on the topic, we've known in unselected patients that cosmesis is worse. The RAPID trial publication does not take into account dosimetric parameters. We also don't know the efficacy and cosmetic outcomes of most of the other partial breast techniques in a randomized fashion. The recent TARGIT-A implies that IORT (50kV photon) has a higher failure rate, and we certainly see our fair share of seromas with it.

So in the end I've seen two approaches to partial breast. You can either say:

1. I'm not willing to treat partial breast because cosmesis might worse and failure rate might be higher. Some physicians refuse to treat partial breast until we have better data (hopefully B-39/RTOG 0413 will settle this).
2. It's worth a patient discussion to see how the patient feels about START or Canadian regimen vs IORT/3D-APBI. Like I wrote before, I'm yet to see a woman in her 60s or older care significantly about her breast cosmesis after treatment.

I personally take approach #2. I think it's wise to have some partial breast technique on standby. My breast surgeon friend refuses to refer her cases to the group in town that only does whole breast treatments. But, all partial breast techniques can be criticized compared to the gold standard of whole breast.
 
Neuronix said:
Oh, RAPID trial. I was unclear from your post what was "unsafe" about the technique. I do take issue with the word "unsafe" because that to me implies cardiac, pulmonary, or some other toxicity beyond cosmesis.

Sure, the publication showed that cosmesis is worse with 3D-APBI than whole breast. Given the five retrospective series on the topic, we've known in unselected patients that cosmesis is worse. The RAPID trial publication does not take into account dosimetric parameters. We also don't know the efficacy and cosmetic outcomes of most of the other partial breast techniques in a randomized fashion. The recent TARGIT-A implies that IORT (50kV photon) has a higher failure rate, and we certainly see our fair share of seromas with it.

So in the end I've seen two approaches to partial breast. You can either say:

1. I'm not willing to treat partial breast because cosmesis might worse and failure rate might be higher. Some physicians refuse to treat partial breast until we have better data (hopefully B-39/RTOG 0413 will settle this).
2. It's worth a patient discussion to see how the patient feels about START or Canadian regimen vs IORT/3D-APBI. Like I wrote before, I'm yet to see a woman in her 60s or older care significantly about her breast cosmesis after treatment.

I personally take approach #2. I think it's wise to have some partial breast technique on standby. My breast surgeon friend refuses to refer her cases to the group in town that only does whole breast treatments. But, all partial breast techniques can be criticized compared to the gold standard of whole breast.
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Very true.


Being able to offer apbi to appropriately selected pts in the community will definitely get you on the good side of some surgeons given the financial incentive for placing apbi devices postoperatively in the office.

It gets you patients through the door and not all of them end up being apbi candidates
 
medgator said:
Being able to offer apbi to appropriately selected pts in the community will definitely get you on the good side of some surgeons given the financial incentive for placing apbi devices postoperatively in the office.
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This particular surgeon feels strongly about any partial breast including 3D-APBI. There is no financial incentive to the surgeons for that treatment. The reason is that patients are often unable to travel to our linacs every day for several weeks due to transport or distance from home issues. Up to one week of treatment is much more reasonable.
 
Good points, but please remember that rock-hard fibrosis after 38.5 Gy/5 days is not simply a cosmetic issue. I'm sure you've seen that. Any recent statements on this topic in published guidelines?
 
seper said:
Good points, but please remember that rock-hard fibrosis after 38.5 Gy/5 days is not simply a cosmetic issue. I'm sure you've seen that. Any recent statements on this topic in published guidelines?
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I'm with you on that. I think outside of maybe certain academic centers, 3DCRT apbi is not ready for prime time, certainly not in the community
 
I've never really understood why virtually EVERY advocated partial breast technique seeks to dramatically reduce overall treatment time. To me, the main argument pro PBI is offering a treatment with less side effects not necessarily the optimal convenience for the patient, when it comes to travelling to treatment. Safety should come first.

The 38.5Gy in 5 days is clearly overdosed. From the biological point of view you are looking at an applied dose which is way over the 39.9/2,66 given in StartB and patients who are supposed to get PBI dont usually qualify for a boost anyway.
So that's probably the problem when people are experiencing more fibrosis with it. Giving more than 6 Gy per day even to a small portion of the breast is probably a bad idea. The trial should have probably tried something like 30Gy given in 5 days. That would still have been enough in terms of local control with less fibrosis.

For the record: I'm giving StartB-fractionation for PBI. 39.9/2.66.
Treatment is done in 15 days. Toxicity is zero, in the few patients I've seen. And I am offering it to selected patients, knowing that I will have less dose to heart/lungs, less skin toxicity (especially outside the PTV) and using a well tested and effective fractionation schedule. Surely, noone has given it for PBI before, but the recurrence rate in/around the cavity is going to be as low as in StartB.
 
Yes, 38.5Gy/5 days is an obviously ill-conceived EBRT prescription. EBRT is not brachy! I think 38.5Gy/5 came from Beaumont in late 90-s.
 
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