BackgroundPatients with high‐risk prostate cancer (HRPC) have multiple accepted treatment options. Because there is no overall survival benefit of one option over another, appropriate treatment must consider patient life expectancy, quality of life, and cost.MethodsThe authors compared quality‐adjusted life years (QALYs) and cost effectiveness among treatment options for HRPC using a Markov model with three treatment arms: (1) external‐beam radiotherapy (EBRT) delivered with 20 fractions, (2) EBRT with 23 fractions followed by low‐dose‐rate (LDR) brachytherapy boost, or (3) radical prostatectomy alone. An exploratory analysis considered a simultaneous integrated boost according to the FLAME trial (ClinicalTrials.gov identifier NCT01168479).ResultsTreatment strategies were compared using the incremental cost‐effectiveness ratio (ICER). EBRT with LDR brachytherapy boost was a cost‐effective strategy (ICER, $20,929 per QALY gained). These results were most sensitive to variations in the biochemical failure rate. However, the results still demonstrated cost effectiveness for the brachytherapy boost paradigm, regardless of any tested parameter ranges. Probabilistic sensitivity analysis demonstrated that EBRT with LDR brachytherapy was favored in 52% of 100,000 Monte Carlo iterations. In an exploratory analysis, EBRT with a simultaneous integrated boost was also a cost‐effective strategy, resulting in an ICER of $62,607 per QALY gained; however, it was not cost effective compared with EBRT plus LDR brachytherapy boost.ConclusionsEBRT with LDR brachytherapy boost may be a cost‐effective treatment strategy compared with EBRT alone and radical prostatectomy for HRPC, demonstrating high‐value care. The current analysis suggests that a reduction in biochemical failure alone can result in cost‐effective care, despite no change in overall survival.
Development and Assessment of a Predictive Score for Vertebral Compression Fracture After Stereotactic Body Radiation Therapy for Spinal Metastases
RADT-10. DEVELOPMENT AND INTERNAL VALIDATION OF A PREDICTIVE SCORE FOR VERTEBRAL COMPRESSION FRACTURE AFTER STEREOTACTIC BODY RADIATION THERAPY FOR SPINAL METASTASES
Abstract PURPOSE Vertebral compression fracture (VCF) is a potential adverse effect following stereotactic body radiation therapy (SBRT) for spinal metastases. In this analysis, we developed and internally validated a risk stratification model for VCF. METHODS From an initial set of 680 treatments, we excluded those with proton therapy, prior surgical intervention, or missing data. The final dataset had 464 treatments in 313 patients. Delineations of VCF and all radiographic components of the spinal instability neoplastic score (SINS) were determined by a radiologist. Recursive partitioning analysis (RPA) was conducted using separate training (70%), internal validation (15%), and test (15%) sets. The log-rank test was used as the criterion for node splitting. RESULTS With a median follow-up of 21 months, we identified 84 VCF (18%), including 65 (77%) de novo and 19 (23%) progressive fractures. There was a median 9 months (IQR: 3 – 21) to VCF. From an initial set of 15 candidate variables, six were identified using the backwards selection method, feature importance testing, and a correlation heatmap. Four were then selected in the highest-fidelity RPA models: epidural tumor extension, lumbar location, gross tumor volume > 10 cc, and SINS > 6. One point was assigned to each variable, and the resulting multivariate Cox model had a concordance of 0.760. Each one point increase in score was associated with increasing rates of VCF. Low-risk lesions (score: 0-1, n=273) had 2-year freedom from VCF of 92%, compared to 80% for intermediate-risk (score: 2, n=99) and 56% (score: 3-4, n=92) for high-risk lesions (p < 0.0001). Cumulative incidence curves with death as a competing risk showed increased VCF with higher scores via Gray’s test (p < 0.001). CONCLUSIONS Our internally-validated model identifies a subgroup of patients with high risk for VCF who may benefit from prophylactic surgical stabilization or vertebroplasty.
Progression and Outcome in Patients with Biclonal Gammopathies
Abstract Background: Patients with monoclonal gammopathies typically have a single clone making a unique type of monoclonal protein, one heavy chain and one light chain. In a small proportion of patients, more than one (typically two) types of monoclonal protein can be seen and differ with respect to the heavy chain or light chain or both. There is limited information on the clinical course of patients with more than one monoclonal protein identified in their serum or urine. Objectives: We report outcomes of patients with more than one monoclonal protein at our institution over the past thirty years. Patients and Methods: We queried the existing clinical database to identify all patients with at least two different monoclonal protein types identified on serum or urine studies during the course of their disease. Retrospective chart review was performed on 551 patients, who had more than one type of monoclonal protein on electrophoresis and/or immunofixation. Results: Among the entire study cohort (N=551), 461 pts (84%) had a biclonal pattern, 7 (1%) had a triclonal pattern and the remaining 83 (15%) had a monoclonal pattern at the time of initial positive study. The median age at the time of initial diagnosis was 69.7 years (range; 32-93); 359 (65%) were male. Among these, 390 were diagnosed as MGUS/BGUS, 18 with SMM, 36 with MM, 20 with WM, and rest with another lymphoproliferative disorders. The median duration between the initial detection of monoclonal protein and the emergence of the biclonal protein was 40 months for the 83 patients, who were monoclonal initially. The distributions of the dominant monoclonal proteins were GK (30%), GL (21%), MK (22%), ML (9%), AK (9%), and AL (8%). The distributions of the second monoclonal proteins were GK (27%), GL (24%), MK (16%), ML (15%), AK (10%), and AL (7%). Overall, 20 patients with a MGUS/BGUS progressed to smoldering or symptomatic myeloma, while 12 patients with an initial diagnosis of SMM progressed to MM. The median estimated follow up for the MGUS/BGUS group and those with SMM were 6.5 years (95% CI; 5, 7) and 9.8 (95% CI; 4, 13), respectively. This translates to 20 progressions over 3822 person years of follow up for the MGUS/BGUS patient group and 12 progressions over 131 person years of follow up for the SMM group. The rate of progression was ~1% per year for patients with MGUS/BGUS and the median estimated time to progression was 2.6 years for the SMM group. (Figure). In majority of patients, the dominant M spike increased with the disease progression. Conclusion: Patients with biclonal gammopathies appear to have a similar rate of progression compared to what has been historically described for MGUS/ SMM population. For the patients who progressed and received treatment, both M proteins typically responded to therapy, and during relapse, the original dominant M protein typically reemerged as the dominant M protein. Figure 1 Figure 1. Disclosures Kumar: Janssen: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Sanofi-Aventis: Consultancy, Research Funding; Onyx Pharmaceuticals: Consultancy, Research Funding; Millennium: The Takeda Oncology Co.: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Skyline Diagnostics: Membership on an entity's Board of Directors or advisory committees.
First Year Medical Student Peer Nominations of Professionalism: A Methodological Detective Story about Making Sense of Non‐Sense