Badr Id Said, MD

Radiation Oncology @UofTDRO 🇨🇦 | | Alumnus @MDAndersonNews 🇺🇸

[Badr Id Said, MD @BadrIdsaid]

1/ 🧵 Thrilled to share that our manuscript on immune modulation during curative RT is now published in the Red Journal! https://t.co/34T1BZYSE4
Here’s what we found about how RT reshapes systemic immunity (and why it may matter for distant mets)

[Allison Fitzgerald, MD, PhD @allisonoconn]

My mom passed away from lung cancer one month ago.

Balancing being a caregiver, family member and oncologist was the hardest thing I’ve ever done.

I wanted to share some reflections on the experience. Thank you ASCO for giving me a platform to do so.

https://t.co/9We5ssnQeB

[Henning Willers, MD, FASTRO @HenningWillers]

⚠️Interesting & thought provoking: Immune modulation by #radiotherapy across different cancers - out in the Feb 1 issue of the #RedJournal

#radbio
@IJROBP @sueyom @BenLok @CGrassberger

https://t.co/7Nn2Q0DIfr

[Adam Grippin @adam_grippin]

🚨Our new paper is out today in Nature! We show that SARS-CoV-2 mRNA vaccines can sensitize tumors to immune checkpoint blockade (ICI) — revealing that clinically available RNA vaccines may act as potent immune modulators. https://t.co/sH13agsz5c

[Badr Id Said, MD @BadrIdsaid]

10/ Acknowledgments 🙌
Huge thanks to my co-authors & the entire PM team!
Special thanks to @MFMilosevic for involving me in this project early in my training 🙏
@pmcancercentre @UofTDRO @RadMedPM @IJROBP

[Badr Id Said, MD @BadrIdsaid]

8/ Clinical takeaways 🩺
If your goal includes systemic control:
• 🎯 Be intentional with LN volumes (lymphocyte-sparing where safe)
• ⏱️ Consider IO timing when Teff pools are most intact
• 🧪 Track RIL/Teff as on-treatment biomarkers in trials

[Badr Id Said, MD @BadrIdsaid]

9/ Limitations ⚠️
• 🧪 Small cohort (n=37)
• 🩸 Blood-only analysis – unclear if systemic changes translate to tumor immune changes
• ⏱️ Single on-treatment timepoint – unknown how long effects persist
• 📊 Unclear if pattern holds with hypofractionation/SBRT

[Badr Id Said, MD @BadrIdsaid]

7/ Conserved across tumor types ♻️
Signals seen in HNC/NSCLC/rectal/STS, including STS w/o chemo → points to RT itself as driver of these systemic changes

[Badr Id Said, MD @BadrIdsaid]

1/ 🧵 Thrilled to share that our manuscript on immune modulation during curative RT is now published in the Red Journal! https://t.co/34T1BZYSE4
Here’s what we found about how RT reshapes systemic immunity (and why it may matter for distant mets)

[Badr Id Said, MD @BadrIdsaid]

6/ Link to distant failure 🌐📉
Patients who developed DM had a greater decline in circulating CD4 Teff post-RT (p=0.049), while those who remained recurrence-free did not.
🧠 This suggests that preserving Teff pools may be critical for achieving systemic control.

[Badr Id Said, MD @BadrIdsaid]

5/ Elective nodal RT matters 🧩🧬
Compared to patients without LN RT, those receiving LN RT (± chemo) had:
• lower frequencies of circulating memory and naïve CD4, naïve CD8 and Treg populations
➡️ These differences persisted independent of receipt of chemotherapy

[Badr Id Said, MD @BadrIdsaid]

4/ Chemokines light the way 🧭
After RT, we observed:
• CXCL12 ↑ (p=0.044)
• MCP-1 ↑ (p<0.001)
→ Both are key signals for monocyte trafficking, suggesting a potential mechanism linking RT to the systemic myeloid shift

[Badr Id Said, MD @BadrIdsaid]

3/ Headline immune shifts 📈📉
RT was associated with:
• Monocytes ↑ (classical & nonclassical; p<0.001)
• B cells ↓ (p<0.001) & NK cells ↓ (p<0.001)
➡️ RT drives a systemic, myeloid-rich, lymphocyte-depleted profile that’s conserved regardless of disease site or chemo use.

[Badr Id Said, MD @BadrIdsaid]

2/ Study design 🧪
Prospective, single-arm (n=37): HNC(8), NSCLC(8), rectal(7), STS(14)
Curative RT ≥45 Gy (1.8–3 Gy/fx); ~54% concurrent chemo
Paired blood: baseline + ≥45 Gy
Assays: Luminex + CyTOF
Median FU: 21 mo; 12/37 developed DM

[Ramez Kouzy, MD @RKouzyMD]

In this new piece just published in @LancetDigitalH we argue why we have one shot at trust with medical AI, and how we’re at risk of blowing it due to poor communication and study design. @dbittermanmd @julian_hong
1/3

https://t.co/lRwn3gcPzX

[Badr Id Said, MD @BadrIdsaid]

Fellowship at @MDAndersonNews officially complete! Grateful for the people, the science, and the mentors that shaped this incredible year. On to the next chapter @pmcancercentre @UofTDRO 🚀📚

[Sean Pitroda, M.D. @SeanPitroda]

Excited to share our recent @Nature paper!

https://t.co/ZPfEqgqXcZ

Tremendous collaborative effort from @UCCancerCenter @UChicago @UChicagoRadonc @rweichselbaum

[Shankar Siva @_ShankarSiva]

📢 🚨#lungcancer peeps. Please consider Prof Andrea Bezjak from @UofT for your next IASLC president! A very deserving candidate and a great representative for #radonc!!! @ldawsonmd #lcsm

[Badr Id Said, MD @BadrIdsaid]

Residency Grad Day X Ghibli 👨‍🎓 ⛩️ @MarissaSherwood @safaviaa @davidymak

[Prajnan Das, MD, MS, MPH @PrajnanDasMD]

Truly a privilege to have @ppisters speak to our rad onc residents and fellows today. So inspiring to hear his vision! @ACKoongMDPhD @ChelseaPinnix @DrEmmaHolliday @MDAndersonNews

[Badr Id Said, MD @BadrIdsaid]

Exciting news: Our oral cavity DM prediction model has been validated as prognostic for OS in a US dataset of over 60,000 patients! Thrilled to see the impact 🌟 . Original paper: https://t.co/ccAE6TSvo3 Latest validation: https://t.co/PcQxrfABGP