Prostate SBRT with Pelvic Nodal Irradiation

[dieABRdie]

Anybody doing this yet?

I'm sure its where we will be in 10 years. Just curious what others thoughts are. I have a high risk patient with 2.5 hour drive each way I'm thinking of offering it. I know the data isn't real great but its either this or permanent ADT.

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[row_RO_row]

SABR in High-Risk Prostate Cancer: Outcomes From 2 Prospective Clinical Trials With and Without Elective Nodal Irradiation - PubMed

SABR in high-risk PCa yields biochemical control rates that may be comparable to that of other radiation therapy modalities. ENI using SABR is feasible and may lead to a significant improvement in biochemical control and in 4yPSARR, without an increase in late gastrointestinal or genitourinary...

pubmed.ncbi.nlm.nih.gov

Some practitioners have adopted this, particularly early on in the pandemic, to reduce exposure and linac resource utilization. I haven't done it off trial myself but I would certainly consider it for a situation like you describe.

Why would elective nodal RT impact the duration of ADT you recommend?

 

[dieABRdie]

SABR in High-Risk Prostate Cancer: Outcomes From 2 Prospective Clinical Trials With and Without Elective Nodal Irradiation - PubMed

SABR in high-risk PCa yields biochemical control rates that may be comparable to that of other radiation therapy modalities. ENI using SABR is feasible and may lead to a significant improvement in biochemical control and in 4yPSARR, without an increase in late gastrointestinal or genitourinary...

pubmed.ncbi.nlm.nih.gov

Some practitioners have adopted this, particularly early on in the pandemic, to reduce exposure and linac resource utilization. I haven't done it off trial myself but I would certainly consider it for a situation like you describe.

Why would elective nodal RT impact the duration of ADT you recommend?

Thanks for the input. I could certainly just treat the prostate, its just been our practice in high risk patients to treat pelvic lymph nodes so I was wondering if people were doing it. If we don't offer a short schedule he won't get treatment at all and would just get ADT. Adding pelvic nodes really doesn't affect that.

 

[evilbooyaa]

Sean Collins at Georgetown is doing 25/5 as per Twitter. I believe Spratt would offer/consider as well. I agree that we'll probably be doing it routinely within 10-15 years.

How high risk is he?

I don't think it's unreasonable to do in a patient who otherwise couldn't get radiation. Is there any RO facility closer to him?

 

[OTN]

Although I don't do SBRT for high risk PCa, given the less than stellar data, SBRT + ADT would be better than nothing, so I would treat the prostate alone with SBRT. I don't think the addition of nodal RT adds a ton to overall cure rates- sorry, Dr. Roach.

 

[Gfunk6]

For high-risk and unfavorable intermediate risk, I've been using "virtual HDR" with SBRT. I deliver an initial 45-50 Gy to pelvic lymph nodes and prostate and then perform a 19 Gy/2 fx boost to the prostate. This is fine with Medicare but won't fly with private payors.

 

[TheWallnerus]

Although I don't do SBRT for high risk PCa, given the less than stellar data, SBRT + ADT would be better than nothing, so I would treat the prostate alone with SBRT. I don't think the addition of nodal RT adds a ton to overall cure rates- sorry, Dr. Roach.

Dan Spratt and Nicholas Zaorsky agree w/ you

 

[medgator]

Can't be any worse than the cryo ADT he might get from some GUs

 

[DoctwoB]

Can't be any worse than the cryo ADT he might get from some GUs

But not nearly as good as Cutting it Out (+/- early salvage xrt)!

 

[mavrik13]

I'd like to see more data before offering off study. My experience during training was quite favorable where it was being done as part of a prospective registry, but it was quite nuanced with how it was performed (i.e. differential CTV/PTV dosing, small margins, low residue diet + simethicone, fleet enema before each fx). I haven't done it since finishing my training.

 

[GI_RadOnc]

My colleague has now done this a few times with the MR linac; 25 / 5 to pelvis; 40/5 to prostate, boost to dominant prostatic nodule to 45-50; urethra stays between 33 and 36. Trying to do our best with the FLAME / HYPOFLAME / POPART data...

 

[jondunn]

My colleague has now done this a few times with the MR linac; 25 / 5 to pelvis; 40/5 to prostate, boost to dominant prostatic nodule to 45-50; urethra stays between 33 and 36. Trying to do our best with the FLAME / HYPOFLAME / POPART data...

This makes a ton of sense to me. Align to dominant nodule/ prostate

 

[SneakyBooger]

I would send for LDR brachy if someone can find a place that does still does it.

I would not do SBRT myself, but would let the patient know he could probably shop around for rad onc's who probably would.

BTW, where in the US is there a place without a linac within 2.5 hrs of home? Sounds like 3rd world, maybe Canada or UK?