2482 - Patient Reported Outcomes Following Brain Reirradiation (reRT) with Proton Therapy

J. L. Anderson¹, B. Hall¹, C. E. Anderson², E. Schreibmann³, H. K. G. Shu³, B. R. Eaton³, J. Zhong³, S. Flampouri⁴, J. Shade⁵, and M. W. McDonald⁶; ¹Emory University School of Medicine, Atlanta, GA, ²Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, ³Department of Radiation Oncology, Winship Cancer Institute of Emory University, Atlanta, GA, ⁴Emory School of Medicine, Atlanta, GA, ⁵Emory, Atlanta, GA, ⁶Emory Proton Therapy Center, Atlanta, GA

Purpose/Objective(s): There are few patient reported outcomes (PROs) data following brain reRT. We hypothesized that the short-term toxicity profile of proton-based brain reRT is modest. Materials/

Methods: We examined patients with prior brain-directed RT who received overlapping brain reRT with pencil beam proton therapy and completed pretreatment and 3-month post-radiation (postRT) PROs as part of a prospective outcomes registry which included PROMIS Fatigue (PF, a 4 point change is the median estimate of a clinically meaningful difference) and Cognitive (PC) instruments and the MD Anderson Symptom Inventory for Brain Tumors (MDASI-BT). Changes in PRO scores over time were analyzed with a Wilcoxan signed rank test for paired data and Mann-Whitney U test to assess correlations with clinical variables.
Results: 26 patients were evaluable with a median age of 54 years (20-75). The most common indications for reRT were progressive or recurrent meningioma (n=10) or glioma (n=7). None received craniospinal re-RT; 7 received concurrent systemic therapy. The prior overlapping RT was fractionated in 19 and SRS in 9, with 4 having multiple prior courses. For reRT, 19 received conventional fractionation (range 45 – 60 Gy), 6 moderate hypofractionation (range 35 – 50 Gy), and 1 proton-based SBRT (30 Gy, 5 fxs). The median nominal cumulative dose was 102 Gy. The median interval from prior RT was 40 months (9-240). There was no statistically significant difference between baseline and 3 month postRT scores for the PF, PC, or mean MDASI-BT Symptom or Interference scores. 11 patients had a 4 point worsening in PF scores at 3 months post-RT: 7 newly entering the moderate severity range and none newly entering severe. For PC, no patient newly reported moderate or worse cognitive impairment at 3 months postRT. Comparing the (baseline, 3 month postRT) median MDASI-BT scores, there was a statistically significant higher (worse) median score for drowsiness (3, 4.5), dry mouth (0, 2), difficulty understanding (1, 2) and appearance (0, 0.5) though the median scores remained low, below a moderate level of severity on the 0-10 MDASI-BT scale. At baseline and 3 months postRT, those with an ECOG performance status (PS) of 1+ (n=13) reported a statistically significant worse PF and MDASI-BT Interference scores compared to those with a baseline ECOG PS=0 (n=12). At 3 months postRT, the four patients requiring steroids reported statistically worse MDASI-BT Interference scores, particularly in relationships and enjoyment of life.
Conclusion: CNS-directed proton reRT was associated with modest changes in patient reported outcomes with ~27% reporting a new moderate level of fatigue at 3 months postRT. Those with a worse baseline ECOG PS and those requiring steroids reported a greater detriment on quality of life. These data are helpful in counseling on short term side effects and shared decision making when considering CNS proton reRT.