boost after hypofx wbi

[Pointless]

---

Members do not see this ad.

What is everyone's opinion regarding boost following hypofx whole breast RT (e.g. 42.5 in 16 fx)? I find myself being much more selective in who I will boost after hypofx treatment, while still routinely boosting all conventionally-fractionated patients. As the BED is essentially equal between conventional and hypofx treatment, it makes no sense to boost one and not the other, but there it is. What is everyone else doing?

 

[Gfunk6]

I still boost 2 Gy x 5, but as you wrote most of my hypofrac are lower risk. So, I boost them less than conventional frac.

 

[Neuronix]

I typically do the Lyon boost, 10 Gy in 4 fractions. That gives you a nice round 20 treatments in 4 weeks. I'd also agree with 10 Gy in 5 fractions or even just giving the last of the 5 fractions in a BID fashion.

 

[Palex80]

We are using the START B hypofx scheme, which is 39.9 Gy in 2.66 Gy / fraction for WBI.

For boost we are giving 10.64-13.3 Gy in 4-5 fractions of 2.66 Gy each.
That's more than then typical 10/2, but we tend to give a lot of 16/2 as well after 50/2, so we like to keep our boost-dose higher anyways... START B gave 10/2.

 

[thesauce]

2Gy x 5 whether we're doing 50/2, 50.4/1.8, or Canadian

 

[OTN]

.

 

[OTN]

2Gy x 5 whether we're doing 50/2, 50.4/1.8, or Canadian

What I do as well.

 

[deleted4401]

Don't treat people I'd boost on Canadian. If they need a boost, I'm doing 61/33.
Sticking to Whelan. I get that there is good UK data, but I'm sticking with my countrymen on this one.

 

[Pointless]

Where I trained, most everyone got boosted after conventional. What are your indications to boost? Age <50 y, high grade, close/positive margins, ER/PR negative?

 

[hot sauce]

Don't treat people I'd boost on Canadian. If they need a boost, I'm doing 61/33.
Sticking to Whelan. I get that there is good UK data, but I'm sticking with my countrymen on this one.

This is essentially our institutional policy unless they are willing and eligible to enroll on RTOG 1005.

 

[medgator]

Astro essentially leaves it up to the discretion of the treating rad onc

https://www.astro.org/Clinical-Practice/Guidelines/Whole-Breast-Fractionation.aspx

Not enough data one way or the other.

 

[Palex80]

Where I trained, most everyone got boosted after conventional. What are your indications to boost? Age <50 y, high grade, close/positive margins, ER/PR negative?

One (or more) of the following:

a) premenopausal status or age <50y
b) >T1
c) N+
d) G3
e) L1
f) V1
g) ER and PR negative (under 10% positive receptors)
h) margin < 4mm
i) multifocal tumor

 

[Gfunk6]

What do L1 and V1 mean?

 

[Palex80]

What do L1 and V1 mean?

Lymphangiosis and Haemangiosis carcinomatosa respectively. 🙂

 

[Brim]

What do L1 and V1 mean?

Methinks L = lymphatic invasion and V = vascular invasion

 

[Gfunk6]

Lymphangiosis and Haemangiosis carcinomatosa respectively. 🙂

Interesting. On the pathology reports I see, they are seldom differentiated (e.g. just LVI). Is it relevant to differentiate them?

 

[Palex80]

Interesting. On the pathology reports I see, they are seldom differentiated (e.g. just LVI). Is it relevant to differentiate them?

I am not sure.

I think L1 = LVI in North America. But noone calls it LVI in Europe (at least where I trained).