Employee; William Beaumont Hospital. P. Paximadis: None. M.M. Dominello: None. I.S. Grills; Greater Michigan Gamma Knife. J.A. Hayman: Research Grant; Blue Cross Blue Shield of Michigan. Board member; ASTRO. R.T. Dess: None. L.J. Pierce: Royalty; UpToDate. D.E. Spratt: None. D.P. Bergsma: None. B. Movsas: Research Grant; Varian Medical Systems, Inc, Philips, Inc. Honoraria; ViewRay. Travel Expenses; Varian Medical Systems, Inc, Philips, Inc. To help organize annual meetings (note: I am slated to become President of ARS in 4/2019). These roles were discussed in advance with ASTRO leadership in this regard.; American Radium Society. Guide QO. S. Jolly: None. 197 Quality of Life Based Total Cost Function (TCF) to Guide Treatment Plan Optimization for Head and Neck Cancer H.P. van der Laan, 1 L. Van den Bosch, 1 A. van der Schaaf, 1 R. Steenbakkers, 1 H. Bijl, 1 M. Dieters, 1 A.V.D. Hoek, 1 S. Both, 2 E. Shuit, 3 and J.A. Langendijk 2 ; 1 Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands, 2 Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands, 3 University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht University, Utrecht, The Netherlands, Utrecht, Netherlands Purpose/Objective(s): A comprehensive range of NTCP-models for common toxicities has recently been developed and validated for definitive radiotherapy for head and neck cancer (HNC). However, it is currently unclear which toxicities are most relevant to patients and thus should get highest priority during treatment plan optimization. Therefore, the aim of this study was to develop a quality of life (QoL)-based Total Cost Function (TCF) that can be used to guide treatment optimization and to select the best treatment plan from a patient’s perspective. Materials/Methods: This prospective cohort study included 750 HNC patients treated with definitive radiotherapy with or without chemotherapy. Baseline patient- and treatment characteristics, as well as physician-rated CTCAEv4 and patient-rated outcome measures (i.e. EORTC QLQ-C30 and EORTC QLQ-HN35) were prospectively scored. QoL was defined as the average score of global health status and 5 functional scales of EORTC QLQ-C30 (scale 0-100) measured at 6, 12, 18 and 24 months. Eleven toxicities were measured at the same time points (Table 1). The impact of each toxicity on QoL was obtained by means of a two-step approach: 1) a principal component analysis (PCA), yielding components explaining most variance among the toxicities; 2) a linear regression analysis incorporating the PCA results and baseline factors to obtain the impact per toxicity and time point on QoL. Results: The impact on QoL differed per toxicity. E.g., dysphagia grade 2- 4 at 6 months reduced QoL with 2.0 points on a 100 points scale, while moderate to severe xerostomia reduced QoL with 0.8 point. The impact of dysphagia grade 2-4 increased over time, with a reduction of 3.4 points at 24 months, resulting in a total reduction of 11.4 points for symptoms that persisted from 6 to 24 month. The impact of xerostomia remained rela- tively stable over time. Other toxicities reduced QoL ranging from less than 1 point for physician-rated loss of taste, xerostomia and sticky saliva at 6 and 12 months, to 4.4 and 4.5 points for patient-rated moderate to severe hoarseness and aspiration at 24 months. Toxicity weightings were added to the NTCP models and combined in the TCF to calculate the comprehensive impact on QoL for each single treatment plan. Conclusion: The impact of physician-rated and patient-rated toxicities on QoL can be quantified in a TCF. The TCF can be used to optimize radi- ation treatment plans, compare plans and select the plan which is expected to provide the optimal spectrum of toxicities resulting in the best quality of life for individual patients. Author Disclosure: H. van der Laan: None. L. Van den Bosch: None. A. van der Schaaf: None. R. Steenbakkers: None. H. Bijl: None. M. Di- eters: None. A.v. Hoek: None. S. Both: None. E. Shuit: None. J.A. Langendijk: Consultant; IBA. 198 Prostate Cancer Anxiety in Survivors, Results from a Population-Based Cohort S. Peterson, 1 R. Basak, 2 D.H. Moon, 3 D. Usinger, 3 S. Walden, 3 A. Katz, 3 P. Godley, 3 and R.C. Chen 3 ; 1 University of North Carolina School of Medicine, Chapel Hill, NC, 2 The University of North Carolina at Chapel Hill, Chapel Hill, NC, 3 University of North Carolina at Chapel Hill, Chapel Hill, NC Purpose/Objective(s): Anxiety in cancer survivors can be harmful because it is associated with depression, poorer adherence to medical treatment, poorer treatment outcomes, and higher rates of mortality. However, anxiety in prostate cancer survivors has not been well-studied and is not well understood. Materials/Methods: In the only modern, fully-prospective, population- based cohort, 951 men diagnosed from 2011-13 with localized prostate cancer were enrolled throughout the state in collaboration with the North Carolina state cancer registry. All patients were prospectively followed, and anxiety assessed using the validated Memorial Anxiety Scale for Prostate Cancer (MAX-PC); 11 items assess prostate cancer anxiety with total score range from 0 (none) to 33 (most anxiety). Multivariable analysis using generalized estimating equations assessed patient and diagnostic factors associated with anxiety. Results: Diversity of the cohort reflects population-based recruitment: 26% non-white, 30% high school education or less, 23% rural. Median age 65. Mean anxiety score for the entire cohort was 6.1 (out of maximum 33) at 12 months, 5.1 at 24 months, 4.8 at 36 months, and 5.0 at 48 months. Mean score at 48 months by subgroup is summarized in Table. Multivar- iable analysis showed that longer follow-up (48 vs 12 months, estimate -1.1, p<.01), lower risk cancer (low vs high, estimate -1.5, p<.05; inter- mediate vs high, estimate -1.5, pZ.04), and older age (estimate -0.1 per year, p<.01) were associated with less anxiety. Conversely, non-white men (vs white, estimate 2.4, p<.01) and lower education (vs college, estimate 2.1, p<.01) were associated with higher anxiety. Active surveillance pa- tients had borderline higher anxiety compared to RT (estimate 1.0, pZ.068). Conclusion: Anxiety in prostate cancer survivors decreases over time, but certain subgroupsdespecially minority patients and those with lower educational attainmentdexperience higher anxiety than other subgroups at 48 months follow-up. While disparities in prostate cancer treatment and survival are well-described, to our knowledge this is the first study demonstrating disparity by race and education in mental well-being in prostate cancer survivors. Abstract 198; Table 1 Mean Prostate Cancer Anxiety score at 48 months by subgroup (range 0e33) Treatment Modality Active surveillance 5.6 Radical prostatectomy 4.9 RT 4.6 Race White 4.2 Non-white 7.4 NCCN Risk Category Low 5.1 Intermediate 4.6 High 5.3 Education High school or less 6.4 College or higher 4.3 Abstract 197; Table 1 Patient-Rated Toxicities Physician-Rated Toxicities Moderate-Severe Xerostomia Dysphagia grade 2-4 Severe Xerostomia Dysphagia grade 3-4 Moderate-Severe Hoarseness Xerostomia grade 2-4 Moderate-Severe Sticky Saliva Sticky Saliva grade 2-4 Moderate-Severe Loss of Taste Loss of Taste grade 2-4 Aspiration grade 2-4 International Journal of Radiation Oncology  Biology  Physics S96