🚨 just published @ESTRO_RT and @EORTC consensus on re-irradiation: definition, reporting,.and clinical decision making . @TheLancetOncol #radonc. A thread 🧵 . 👇 1/n.

RT @FelixEhretMD: Treating adrenal gland metastases with SBRT? Check out our latest guide - huge thanks to all collaborators! @ASTRO_org @E….

RT @KatsuakiMaehara: 1/3. 🫁 #TTF-1 is a new marker to identify patients best suited for #lung cancer KRAS inhibitors 🫁. 🫁 #Sotorasib - #KRA….

RT @FelixEhretMD: The @ESTRO_RT is conducting a survey on reirradiation for brain tumors - please take a moment to fill it out and help us….

RT @mtugceyilmaz: 🚨 Just out in Red Journal! . We analyzed our 191-patient H&N reirradiation cohort, with a specific focus on toxicity and….

9/.🙏 Huge thanks to our fantastic team—especially.@amithjkamath.@mreyesag .@NAndratschke. — for driving this important work forward and to @krebsliga for the support!.

8/.✅ Our findings support:.▪️ Standardized review protocols.▪️ Tools that quantify dose impact.▪️ AI to assist in reviewing contours—not just generating them.

7/.⚠️ Clinical takeaway:.Unnecessary edits to AI contours may waste time and offer no dose benefit. In a world moving toward auto-segmentation, we need smarter, dose-aware review strategies—not just cautious habits.

6/.🧠 Why did experts decide as they did?.Thematic analysis (aided by LLMs 🤖) revealed 3 main drivers:.1️⃣ Proximity to OARs.2️⃣ Size of the change.3️⃣ Shape/geometry of the modification.But these didn’t consistently predict dosimetric impact.

5/.🧮 Inter-evaluator agreement was modest:.Cohen’s Kappa ranged from 0.33 to 0.74.Only 52% of evaluator pairs showed strong agreement.This variability points to subjectivity in contour review.

4/.📉 Key results:.⚠️ 42% of “no change” variations were misjudged as “Worse”.❌ No evaluator labeled any variation as “Better”—even though 4 variations reduced OAR dose.Overestimation of detrimental effects was common.

3/.📦 Study design:.▪️ 14 glioblastoma patients.▪️ 54 systematically modified CTVs.▪️ 4 radiation oncologists & 3 physicists.Each variation was labeled “Better,” “No change,” or “Worse” based on dosimetry (ground truth), and then by experts using images only.

2/.🔗 We asked:.💡 Can experts visually estimate the dosimetric impact of target volume changes?.🧠 Do they agree with each other?.💬 What factors shape their decisions during contour review?.

With AI-driven auto-contouring now routine, the role of radiation oncologists is shifting—from manual delineation to reviewing AI-generated contours. But how well does our inner compass detect which changes really impact OAR dose?. 📊 We put this to the test in our new study.👇.

@Unispital_USZ 🎓 This study was part of the doctoral thesis of the stellar Katja Dähler @UZH_ch.

@Unispital_USZ 🚀 What’s next?.📌 Prospective data from E²-RADIatE ReCare and others are needed to.- develop validated cumulative dose constraints.- explore applicability in other tumor sites.- optimize integration with systemic therapy.

@Unispital_USZ ⚠️ Notably:.Repeat organ irradiation carried the highest risk for pneumonitis, potentially due to exposure of previously unirradiated lung tissue. This supports the idea that organ-specific reirradiation risks depend on both overlap and cumulative dose distribution.

@Unispital_USZ 🧠 To our knowledge, this is the first validation of the ESTRO/EORTC reirradiation classification showing differences in toxicity and local control in NSCLC thoracic reirradiation. It offers a clinical framework to stratify patients undergoing reirradiation.

@Unispital_USZ Importantly:. 📊 Favorable median overall survival: 26.3 months. 📊 No significant difference in OS (p = 0.43) or PFS (p = 0.58) between reirradiation types. 🟢 Grade 5 events were rare — only one fatal case of esophageal rupture.

@Unispital_USZ 🔍 Key findings:. ✅ Repeat organ irradiation had the best local control. 🚨 Grade ≥3 toxicity occurred in 7.3% overall. 🚨 Pneumonitis was most common (2.7%) and more frequent in repeat organ irradiation (9.1%) vs. type 1 (0%, p = 0.02).

@Unispital_USZ - Type 1: overlapping irradiated volumes (using the 50% isodose line). - Type 2: no overlap, but cumulative doses raise toxicity concern (i.e. exceeding first-course constraints). - Repeat organ irradiation: no overlap, and cumulative doses within first-course constraints.