Browsing by Author "Nabavizadeh, Nima"

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    Clinical outcome and prognostic factors for central neurocytoma: twenty year institutional experience
    (Springer, 2016-01) Imber, Brandon S.; Braunstein, Steve E.; Wu, Fred Y.; Nabavizadeh, Nima; Boehling, Nicholas; Weinberg, Vivian K.; Tihan, Tarik; Barnes, Michael; Mueller, Sabine; Butowski, Nicholas A.; Clarke, Jennifer L.; Chang, Susan M.; McDermott, Michael M.; Prados, Michael D.; Berger, Mitchel S.; Haas-Kogan, Daphne A.; Department of Medicine, IU School of Medicine
    Central neurocytomas are uncommon intraventricular neoplasms whose optimal management remains controversial due to their rarity. We assessed outcomes for a historical cohort of neurocytoma patients and evaluated effects of tumor atypia, size, resection extent, and adjuvant radiotherapy. Progression-free survival (PFS) was measured by Kaplan-Meier and Cox proportional hazards methods. A total of 28 patients (15 males, 13 females) were treated between 1995 and 2014, with a median age at diagnosis of 26 years (range 5-61). Median follow-up was 62.2 months and 3 patients were lost to follow-up postoperatively. Thirteen patients experienced recurrent/progressive disease and 2-year PFS was 75% (95% CI 53-88%). Two-year PFS was 48% for MIB-1 labeling >4% versus 90% for ≤4% (HR 5.4, CI 2.2-27.8, p = 0.0026). Nine patients (32%) had gross total resections (GTR) and 19 (68%) had subtotal resections (STR). PFS for >80% resection was 83 versus 67% for ≤80% resection (HR 0.67, CI 0.23-2.0, p = 0.47). Three STR patients (16%) received adjuvant radiation which significantly improved overall PFS (p = 0.049). Estimated 5-year PFS was 67% for STR with radiotherapy versus 53% for STR without radiotherapy. Salvage therapy regimens were diverse and resulted in stable disease for 54% of patients and additional progression for 38 %. Two patients with neuropathology-confirmed atypical neurocytomas died at 4.3 and 113.4 months after initial surgery. For central neurocytomas, MIB-1 labeling index >4% is predictive of poorer outcome and our data suggest that adjuvant radiotherapy after STR may improve PFS. Most patients requiring salvage therapy will be stabilized and multiple modalities can be effectively utilized.
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    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.