Browsing by Author "Fuller, Clifton David"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Improved human observer performance in digital reconstructed radiograph verification in head and neck cancer radiotherapy.
    (Springer, 2015-10) Sturgeon, Jared D.; Cox, John A.; Mayo, Lauren L.; Gunn, G. Brandon; Zhang, Lifei; Balter, Peter A.; Dong, Lei; Awan, Musaddiq; Kocak-Uzel, Esengul; Mohamed, Abdallah Sherif Radwan; Rosenthal, David I.; Fuller, Clifton David; Department of Radiation Oncology, IU School of Medicine
    Purpose: Digitally reconstructed radiographs (DRRs) are routinely used as an a priori reference for setup correction in radiotherapy. The spatial resolution of DRRs may be improved to reduce setup error in fractionated radiotherapy treatment protocols. The influence of finer CT slice thickness reconstruction (STR) and resultant increased resolution DRRs on physician setup accuracy was prospectively evaluated. Methods: Four head and neck patient CT-simulation images were acquired and used to create DRR cohorts by varying STRs at 0.5, 1, 2, 2.5, and 3 mm. DRRs were displaced relative to a fixed isocenter using 0–5 mm random shifts in the three cardinal axes. Physician observers reviewed DRRs of varying STRs and displacements and then aligned reference and test DRRs replicating daily KV imaging workflow. A total of 1,064 images were reviewed by four blinded physicians. Observer errors were analyzed using nonparametric statistics (Friedman’s test) to determine whether STR cohorts had detectably different displacement profiles. Post hoc bootstrap resampling was applied to evaluate potential generalizability. Results: The observer-based trial revealed a statistically significant difference between cohort means for observer displacement vector error (p = 0.02) and for Z-axis (p < 0.01). Bootstrap analysis suggests a 15% gain in isocenter translational setup error with reduction of STR from 3 mm to ≤2 mm, though interobserver variance was a larger feature than STR-associated measurement variance. Conclusions: Higher resolution DRRs generated using finer CT scan STR resulted in improved observer performance at shift detection and could decrease operator-dependent geometric error. Ideally, CT STRs ≤2 mm should be utilized for DRR generation in the head and break neck.
  • Thumbnail Image
    Item
    Use of the g-index for assessment of citation-based scholarly activity of United States radiation oncology residents and subsequent choice of academic versus private practice career
    (Elsevier, 2019-04-30) McClelland, Shearwood, III; Mitin, Timur; Nabavizadeh, Nima; Fuller, Clifton David; Thomas, Charles R., Jr.; Jaboin, Jerry J.; Radiation Oncology, School of Medicine
    Introduction: The Hirsch index (h-index) evaluates citation-based scholarly activity, but has limited ability to acknowledge those publishing a smaller number of manuscripts with exceedingly high citations. The g-index addresses this limitation by assessing the largest number of manuscripts (g) by an author cited at least (g × g) times, but has yet to be applied to radiation oncology resident productivity. Methods: A list of recent radiation oncology resident graduates (comprising 86% of the 2016 graduating class) and their post-residency career choice was compiled. The Scopus bibliometric citation database was searched to collect and calculate g-index data for each resident. Results: The mean g-index score for all resident graduates was 7.16. Residents with a PhD had significantly higher g-index scores (11.97 versus 5.80; p < 0.01), while there was no statistically significant difference in g-index scores between male and female residents. Residents choosing academic careers had higher g-index scores than those choosing private practice (9.47 versus 4.99; p < 0.01). Programs graduating at least three residents produced significantly higher g-index scores/resident than those graduating two residents, and while comprising only 25% of programs and 45% of residents, produced 60% of academic careers (p < 0.02). Conclusion: Radiation oncology resident graduates published on average a minimum of seven manuscripts cited at least 49 times. PhD-degree graduates had significantly higher g-index scores, as did residents choosing academic over private practice careers. There was no significant gender-related difference in g-index score regardless of career choice. The majority of academic careers are produced from programs graduating at least three residents.