2023 World Conference on Lung Cancer (Posters)-P1.28. Cessation of Marrow Proliferation on FLT-PET with Low RT Doses During ChemoRT for NSCLC Correlates with Lymphocyte Decline

P1.28. Cessation of Marrow Proliferation on FLT-PET with Low RT Doses During ChemoRT for NSCLC Correlates with Lymphocyte Decline - PDF(Slides)

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Researchers at the Peter MacCallum Cancer Centre in Australia conducted a study to investigate the correlation between bone marrow proliferation and lymphocyte decline in non-small cell lung cancer (NSCLC) patients receiving concurrent chemoradiotherapy (chemoRT). The study utilized serial FLT-PET scans to track changes in bone marrow proliferation during treatment.<br /><br />The study included 28 stage III NSCLC patients who underwent chemoRT with a radiation dose of 60 Gy, along with concurrent cisplatin/etoposide or carboplatin/paclitaxel. FLT-PET scans were obtained at baseline, week 2, and week 4 of treatment. The maximum standardized uptake value (SUVmax) in each isodose volume of interest (VOI) represented peak marrow proliferation. The dose at which marrow uptake was visually unapparent was determined for each patient at weeks 2 and 4, representing the lowest radiation dose resulting in ablation.<br /><br />The results showed that FLT uptake ceased in bone marrow volumes exposed to doses above 4 Gy on week 2 and week 4 FLT-PET scans. Lymphocyte counts dropped steadily during chemoRT. There was a significant correlation between the percentage of proliferating bone marrow ablated by radiation and the drop in lymphocyte counts from baseline to week 4. This correlation appeared to be linear and became more apparent with time.<br /><br />The researchers concluded that bone marrow proliferation decreased with increasing radiation doses during chemoRT for NSCLC and ceased with doses above 4 Gy. The percentage of marrow ablated on week 4 FLT-PET scans was strongly correlated with lymphocyte decline. These findings suggest that bone marrow is an organ at risk from low radiation doses during CRT for NSCLC. The study highlights the importance of monitoring bone marrow proliferation and lymphocyte counts during treatment to optimize immunotherapy outcomes.

Asset Subtitle

Michael MacManus

Meta Tag

Speaker Michael MacManus

Topic Local-Regional NSCLC

Keywords

Peter MacCallum Cancer Centre

Australia

bone marrow proliferation

lymphocyte decline

non-small cell lung cancer

NSCLC

chemoradiotherapy

FLT-PET scans

radiation dose

chemoRT