Research about the interruption of EBRT and impacts on effectiveness... Also, how does one weigh the risks of continuing tx in time of COVID

[Rich_Rad]

Hi all,

Does anyone have any information on research of impacts of effectiveness if EBRT needs to be interrupted due to whatever reasons (eg. mechanical problems with the equipment, COVID infection of the patient, or desire on patient’s part to avoid infection)?

I am 16 treatments into a 44 treatment EBRT plan. Today the machine went down, and my treatment was cancelled.. no big deal, they say, we’ll just add one onto the end...

In the meantime, I got my most recent HIV bloodwork back, and have the the situation of having numbers that demonstrate the impact of the cancer and the treatments on my immune system. My T4 cells have gone down (as expected) but seem really significant to me... T4 cells went from 1115 on 3/2019, 694 on 1/20 and 279 on 3/26/20... call is into my infectious disease provider to consult on this. Sitting with the concerns that I am sure that most of us are...

Any input that you have would be helpful...

My prostate cancer stats are in profile...

Thanks,

Rich Rad

[timotur]

The decrease in lymphocytes is entirely normal with pelvic radiation. My absolute lymphocyte count went from 1325 to 274 before/after 25 sessions of IMRT, and have recovered to 500 six months afterwards.

Given the uncertainty with regard to the effectiveness of pelvic nodal irradiation (PNI) for prostate cancer, we aimed to determine whether patients with prostate cancer who are treated with PNI are at a higher risk of developing radiation-related lymphopenia (RRL). Methods and materials:The electronic charts of 886 consecutive patients treated with radiation therapy for prostate cancer between 2006 and 2018 at our institution were retrospectively analyzed. Qualifying patients were those with total lymphocyte counts within 1 year before and 3 to 24 months after the start of radiation therapy. Lymphopenia was the primary outcome, and overall survival and biochemical progression-free survival were secondary outcomes. Results:Thirty-six patients with and 95 patients without PNI qualified for inclusion. In the PNI cohort, 61.1% of patients developed RRL (median follow-up total lymphocyte count < 1000 cells/μL) versus 26.3% of non-PNI patients (P < .001). On univariate analysis, initial prostate-specific antigen level, baseline lymphopenia, treatment modality, PNI status, increased planned target volume, and androgen deprivation therapy administration were all significant predictors of RRL (P < .05). On multivariate analysis, PNI status was a significant predictor of RRL (hazard ratio [HR], 3.42; 95% confidence interval [CI], 1.22-9.61; P < .001), as were initial prostate-specific antigen values (HR, 1.05; 95% CI, 1.00-1.11; P = .006) and baseline lymphopenia (HR, 8.32; 95% CI, 2.19-31.6; P = .007). RRL was not predictive for biochemical progression-free survival, distant metastasis, or overall survival on multivariate analysis, but the number of events was likely insufficient for these analyses. Conclusions:The higher risk of RRL among patients with PNI comports with other papers that show that increased treatment volumes are associated with higher rates of RRL. Mounting evidence for the adverse effects of RRL on clinical outcomes supports the significance of our findings and suggests that further studies are needed on RRL as a potential harm of PNI that may affect the interpretation of results from clinical trials of PNI.

europepmc.org/article/PMC/6...

[Rich_Rad in reply to timotur]

Thanks so much Tim...

[Tall_Allen]

No worries about delaying prostate radiation for a few days - the cancer grows back very slowly. The bigger question is why are they still putting you through a 44 treatment plan? ASTRO has strongly endorsed fewer treatments. You can ask them to accelerate the remainder of your schedule:

pcnrv.blogspot.com/2018/10/...

And a combo treatment with whole pelvic external beam radiation and brachytherapy to the prostate would only require 20 total external beam treatments, and is much more effective for your diagnosis. You can possibly still do that:

pcnrv.blogspot.com/2017/03/...

Your CD4 decline is troubling, especially since it started well before any radiation. I'm sure you had a bone scan that showed no infiltration into the bones. Perhaps your HAART has become resistant? There are clinical trials to test whether some HIV meds can be used to treat covid-19 - too early to tell.

[Rich_Rad in reply to Tall_Allen]

Thanks so much Allen... always so helpful to get your feedback... had made the decision to not go with the brachytherapy boost, b/c Yale’s radiologist said no one in CT is doing it... probably should have explored it further... we looked at the shorter treatment plan with higher doses at the end... i think it was 28 total... but concern about location of my particular cancer butting up (pardon the pun) to the rectum lead to the decision to do the 44...

As for the HAART becoming resistant... i have been undetectable (HIV viral load that is) for 9 + years... and i still am... do you mean HAART resistance Impacting my CD4 count. My ID doctor is convinced that CD4 decline is totally due to the cancer and its treatment...

I will give an update as I make my way through this... I am hesitant to change course at this time, but there is fear of exposure that is weighing on me..

Rich

[Tall_Allen in reply to Rich_Rad]

Thanks for explaining- that makes sense that the cancer abutting the rectum requires lower daily doses. I'm not sure why the cancer would affect your CD4 levels if it has not invaded your bone marrow, and you are still undetectable. Why does your ID doctor think that might be? Your treatment up to your current radiation has only been ADT, and ADT increases immune response. It's puzzling to me.

[Rich_Rad in reply to Tall_Allen]

I will ask him on Friday... I think he might think it was my immune systems response to the cancer in the first place??? Also, the stress of the aborted robotic prostatectomy, in December?? Not sure if that’s a potential cause of fluctuations... will review with him at my telemedicine visit on Friday...

Thanks again Allen! I am super grateful for your help!

[Tall_Allen in reply to Rich_Rad]

Let me know, thanks.