"This is the first randomized trial that demonstrated the feasibility and safety of performing biologically adaptive radiation therapy escalation in a multicenter setting in patients with stage III NSCLC. This preliminary analysis did not show an improvement in overall local regional tumor control," Dr. Kong reported.

In the second study, Dr. Saskia Cooke, The Netherlands Cancer Institute in Amsterdam, Netherlands, reports on local and regional failure in the phase II PET-Boost trial (NCT01024829). In this study, patients with stage II-III non-small cell lung cancer (NSCLC) were treated with hypofractionated dose escalation to either the primary tumor as a whole (Arm A) or the high fluorodeoxyglucose (FDG)-uptake region inside the PT (> 50% SUVmax; Arm B).


The trial randomly assigned 107 patients--82% had stage III disease and most patients (72%) received concurrent chemoradiotherapy. In Arms A and B, median gross tumor volume (GTV) for the primary tumor was 100 and 115 cm3, respectively; median GTV for the involved lymph nodes was 18 and 20 cm3, respectively. Median fraction dose was 3.25 Gy to planning target volume (PTV) to the entire primary tumor and 3.50 Gy to PTV 50% SUVmax, resulting in total planned physical dose of 78.0 and 84.0 Gy, in 24 fractions. Median overall treatment time was 34 days in both arms, and median follow-up for CT scans in central review was 12.6 months.

In a previous report, the authors revealed that the primary tumor was non-measurable on follow-up in 27% of patients [Cooke S, 2020]. Of the 12 patients in Arm A who experienced locoregional failure, 2 had local failure (LF) without regional failure (RF) and 9 had RF without LF. Of the 15 patients in Arm B, 4 had LF without RF and 10 had RF without LF. In Arms A and B, respectively, the 2-year cumulative incidence of LF was 11% and 18%, and 28% and 25% for RF. The authors concluded that "dose escalation to the whole PT or 50% SUVmax in patients with NSCLC led to excellent local control rates in both treatment arms". However, few patients were evaluable for assessment of local failure at 2-years, grade 5 toxicity rates was previously reported to be 16% [van Diessen J, 2018], with 3-year OS rates of only 37% in armA and 33% in armB, respectively.


About the IASLC:
The International Association for the Study of Lung Cancer (IASLC) is the only global organization dedicated solely to the study of lung cancer and other thoracic malignancies. Founded in 1974, the association's membership includes nearly 7,500 lung cancer specialists across all disciplines in over 100 countries, forming a global network working together to conquer lung and thoracic cancers worldwide. The association also publishes the Journal of Thoracic Oncology, the primary educational and informational publication for topics relevant to the prevention, detection, diagnosis, and treatment of all thoracic malignancies.

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