Jeff Ryckman, Associate Professor of Radiation Oncology at WVU Medicine Camden Clark Medical Center, shared a post on by Masahiro Torasawa, Medical Oncologist at Juntendo University, on X:
“Very important study. Great read!
Lymphopenia-sparing techniques may be meaningful here. Shortening the ‘number of insults’ from 10 fractions to a 5-fraction regimen could help. Beyond fewer fractions, planning should intentionally spare the thoracic vertebral bodies, aorta, and heart to reduce exposure of marrow and the circulating blood pool.
My unsolicited take: The median lung V5 on TREASURE was approximately 60%. With long craniocaudal central/N2 targets, lung V5 often becomes constraint-saturated around this level. Continuing to force V5 below 60% does not make the low-dose bath disappear. It may simply redirect dose through the heart, aorta, and thoracic vertebral bodies. RT planning is like stepping on a balloon: the dose has to go somewhere. In this setting, selectively relaxing lung V5 may meaningfully reduce integral exposure to more consequential immune structures.
I routinely deliver 20-25 Gy/5 fx IMRT during maintenance single-agent immunotherapy in these scenarios, which has generally appeared well tolerated without unexpected safety signals.
Random thoughts aside, congratulations to the authors! Really looking forward to NRG-LU007/RAPTOR and JCOG2002, although neither will directly answer whether a 5-fraction thoracic regimen reduces the depth or duration of radiation-induced lymphopenia .”
Quoting Masahiro Torasawa‘s post:
“Important phase III data are still awaited before drawing definitive conclusions.
RAPTOR (NRG-LU007) is evaluating consolidative radiation after first-line chemo-IO.
JCOG is also conducting JCOG 2002 (yES-TRT), a randomized phase III trial testing the addition of TRT to atezo- or durva-based therapy in ES-SCLC, with approx. 240 pts planned for randomization.
Title: JCOG2002: A randomized phase III study of thoracic radiotherapy for extensive stage small cell lung cancer.
Authors: Kaname Nosaki, Yoshitaka Zenke, Shogo Nomura, Tomonari Sasaki, Seiji Niho, Kiyotaka Yoh, Hiroshige Yoshioka, Yukio Hosomi, Isamu Okamoto, Hiroyasu Kaneda, Hiroaki Akamatsu, Hiroaki Okamoto, Keita Sasaki, Yuta Sekino, Hidehito Horinouchi, Yuichiro Ohe
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The optimal role and appropriate patient selection for consolidative TRT in the immunotherapy era remains an important open question.”
