Treatment planning and outcomes effects of reducing the preferred mean esophagus dose for conventionally fractionated non‐small cell lung cancer radiotherapy

Abstract

Based on an analysis of published literature, our department recently lowered the preferred mean esophagus dose (MED) constraint for conventionally fractionated (2 Gy/fraction in approximately 30 fractions) treatment of locally advanced non‐small cell lung cancer (LA‐NSCLC) with the goal of reducing the incidence of symptomatic acute esophagitis (AE). The goal of the change was to encourage treatment planners to achieve a MED close to 21 Gy while still permitting MED to go up to the previous guideline of 34 Gy in difficult cases. We compared all our suitable LA‐NSCLC patients treated with plans from one year before through one year after the constraint change. The primary endpoint for this study was achievability of the new constraint by the planners; the secondary endpoint was reduction in symptomatic AE. Planners were able to achieve the new constraint in statistically significantly more cases during the year following its explicit implementation than in the year before (P = 0.0025). Furthermore, 38% of patients treated after the new constraint developed symptomatic AE during their treatment as opposed to 48% of the patients treated before. This is a clinically desirable endpoint although the observed difference was not statistically significant. A subsequent power calculation suggests that this is due to the relatively small number of patients in the study.

A Prospective Study on Deep Inspiration Breath Hold Thoracic Radiation Therapy Guided by Bronchoscopically Implanted Electromagnetic Transponders

“…High-dose stereotactic body radiation therapy (SBRT) results in excellent local control for early-stage non-small cell lung cancer (NSCLC) [1][2][3][4][5] and metastatic disease [6][7][8][9][10], and conventionally fractionated RT with concurrent chemotherapy is the standard of care in NSCLC patients who are medically inoperable or have unresectable locally advanced disease [11][12][13]. Toxicities of thoracic RT are related to the volume of normal tissue irradiated, tumor size and location, and dose [14][15][16][17][18][19]. A major challenge in thoracic RT is respiratory tumor and organ-at-risk (OAR) motion.…”