Gross Tumor and Intracranial Control Benefits with Fractionated Radiotherapy Compared with Stereotactic Radiosurgery for Patients with WHO Grade 2 Meningioma.

OBJECTIVE: Surgical resection is the mainstay of treatment for WHO grade 2 meningioma. Fractionated radiation therapy (RT) is frequently used after surgery, though many centers utilize stereotactic radiosurgery (SRS) for recurrence or progression. Herein, we report disease control outcomes from an institutional cohort with adjuvant fractionated RT versus salvage SRS. METHODS: We identified 32 patients from an institutional database with WHO grade 2 meningioma and residual/recurrent tumor treated with either SRS or fractionated RT. Patients were treated between 2007 and 2021 and had at least 1 year of follow-up. Kaplan-Meier estimators were used to determine gross tumor control (GTC) and intracranial control (IC). Univariate Cox proportional hazards models using biologically effective dose (BED) as a continuous parameter were used to assess for dose responses. RESULTS: With a median follow-up of 5.5 years, 13 patients (41%) received SRS to a recurrent or progressive nodule, 2 (6%) fractionated RT to a recurrent or progressive nodule, and 17 (53%) adjuvant fractionated RT following subtotal resection. Five-year GTC was higher with fractionated RT versus SRS (82% vs. 38%, P = 0.03). Five-year IC was also better with fractionated RT versus SRS (82% vs. 11%, P < 0.001). On univariate analysis, increasing BED10 was significantly associated with better GTC (P = 0.039); increasing BED3 was not (P = 0.82). CONCLUSIONS: In this patient cohort, GTC and IC were significantly higher in patients treated with adjuvant fractionated RT compared with salvage SRS. Increasing BED10 was associated with better GTC. Fractionated RT may provide a better therapeutic ratio than SRS for grade 2 meningiomas.

Patterns of failure after radiosurgery for WHO grade 1 or imaging defined meningiomas: Long-term outcomes and implications for management.

BACKGROUND: We analyzed long-term control and patterns of failure in patients with World Health Organization Grade 1 meningiomas treated with definitive or postoperative stereotactic radiosurgery at the authors' affiliated institution. METHODS: 96 patients were treated between 2004 and 2019 with definitive (n = 57) or postoperative (n = 39) stereotactic radiosurgery. Of the postoperative patients, 17 were treated adjuvantly following subtotal resection and 22 were treated as salvage at time of progression. Patients were treated to the gross tumor alone without margin or coverage of the dural tail to a median dose of 15 Gy. Median follow up was 7.4 years (inter-quartile range 4.8-11.3). Local control, marginal control, regional control, and progression-free survival were analyzed. RESULTS: Local control at 5 and 10 years was 97 % and 95 %. PFS at 5 and 10 years was 94 % and 90 % with no failures reported after 6 years. Definitive and postoperative local control were similar at 5 (95 % [82-99 %] vs. 100 %) and 10 years (92 % [82-99 %] vs. 100 %). Patients treated with postoperative SRS did not have an increased marginal failure rate (p = 0.83) and only 2/39 (5 %) experienced recurrence elsewhere in the cavity. CONCLUSIONS: Stereotactic radiosurgery targeting the gross tumor alone provides excellent local control and progression free survival in patients treated definitively and postoperatively. As in the definitive setting, patients treated postoperatively can be treated to gross tumor alone without need for additional margin or dural tail coverage.

Survival outcomes for patients with T3N0M0 squamous cell carcinoma of the glottis treated with definitive radiation alone versus chemoradiation.

BACKGROUND: Given the poor lymphatics of the glottis, we evaluated omission of chemotherapy in patients treated definitely for T3N0M0 squamous cell carcinoma (SCC) of the glottis. METHODS: We performed survival analysis of patients with T3N0M0 SCC of the glottis identified in the National Cancer Database treated with radiation alone versus chemoradiation. RESULTS: A total of 3785 patients were identified. Patients age ≥70 and those with comorbidities were less likely to receive chemotherapy (odds ratio [OR] 0.30, 95% CI [0.25-0.37] and 0.48 [0.31-0.76], respectively). Five-year OS was lower in patients treated with radiation versus chemoradiation (33.8% [30.3%-37.2%] vs. 58.0% [55.8%-60.0%]). In patients <70 with no comorbidities this difference persisted (51.0% [44.5%-57.0%] versus 66.7% [64.0%-69.3%]). CONCLUSION: Overall survival was higher in patients treated with chemoradiation compared to radiation alone, even when controlling for age and comorbidities. Radiotherapy with chemotherapy omission is not appropriate in patients with T3N0M0 SCC of the glottis.

Second Primary Malignancies in Diffuse Large B-cell Lymphoma Survivors with 40 Years of Follow Up: Influence of Chemotherapy and Radiation Therapy.

Purpose: Previous studies have shown an increased risk of second primary malignancies (SPMs) in survivors of diffuse large B-cell lymphoma (DLBCL). Survivors live longer due to the intensification of and improvements in therapy; thus, we aimed to characterize SPM patterns in patients with DLBCL by treatment modality. Methods and Materials: Standardized incidence ratio and absolute excess risk of SPMs were assessed in patients with primary DLBCL from 1975 to 2016 in the National Cancer Institute's Surveillance, Epidemiology, and End Results Program. A subgroup analyses based on, sex, race, age at the time of diagnosis, latency, and treatment modality were performed. Propensity score-adjusted cumulative incidence curves were generated, stratified by treatment and accounting for death as a competing risk. Results: In total, 45,946 patients with DLBCL were identified with a mean follow up of 70 months. Overall, 9.2% of patients developed an SPM with a standardized incidence ratio of 1.23 (95% confidence interval, 1.20-1.27). There was no difference in SPM risk between men and women or Black and White patients. Patients age <25 years were particularly susceptible to the development of SPMs, with a risk 2.5 times greater than patients aged 50 to 74 years. Temporal patterns showed increasing risk of solid malignancies and decreasing risk of hematologic malignancies over time, with bladder cancer posing the greatest absolute excess risk of any cancer type after 15 years. Patients treated with radiation therapy (RT), chemotherapy (CT), and chemoradiation therapy (CRT) all had an increased risk of SPM development compared with the general population. The cumulative incidence of SPMs was the lowest in patients treated with RT and the highest when treated with CRT. In the modern treatment era, the cumulative incidence of SPM for patients treated with CT versus CRT was not significantly different. Conclusions: In this large population-based study, we demonstrate unique SPM risk patterns based on age, latency, and treatment modality that have important implications for the treatment and screening of patients diagnosed with DLBCL.

18FDG positron emission tomography mining for metabolic imaging biomarkers of radiation-induced xerostomia in patients with oropharyngeal cancer.

PURPOSE: Head and neck cancers radiotherapy (RT) is associated with inevitable injury to parotid glands and subsequent xerostomia. We investigated the utility of SUV derived from 18FDG-PET to develop metabolic imaging biomarkers (MIBs) of RT-related parotid injury. METHODS: Data for oropharyngeal cancer (OPC) patients treated with RT at our institution between 2005 and 2015 with available planning computed tomography (CT), dose grid, pre- & first post-RT 18FDG-PET-CT scans, and physician-reported xerostomia assessment at 3-6 months post-RT (Xero 3-6 ms) per CTCAE, was retrieved, following an IRB approval. A CT-CT deformable image co-registration followed by voxel-by-voxel resampling of pre & post-RT 18FDG activity and dose grid were performed. Ipsilateral (Ipsi) and contralateral (contra) parotid glands were sub-segmented based on the received dose in 5 Gy increments, i.e. 0-5 Gy, 5-10 Gy sub-volumes, etc. Median and dose-weighted SUV were extracted from whole parotid volumes and sub-volumes on pre- & post-RT PET scans, using in-house code that runs on MATLAB. Wilcoxon signed-rank and Kruskal-Wallis tests were used to test differences pre- and post-RT. RESULTS: 432 parotid glands, belonging to 108 OPC patients treated with RT, were sub-segmented & analyzed. Xero 3-6 ms was reported as: non-severe (78.7%) and severe (21.3%). SUV- median values were significantly reduced post-RT, irrespective of laterality (p = 0.02). A similar pattern was observed in parotid sub-volumes, especially ipsi parotid gland sub-volumes receiving doses 10-50 Gy (p < 0.05). Kruskal-Wallis test showed a significantly higher mean RT dose in the contra parotid in the patients with more severe Xero 3-6mo (p = 0.03). Multiple logistic regression showed a combined clinical-dosimetric-metabolic imaging model could predict the severity of Xero 3-6mo; AUC = 0.78 (95%CI: 0.66-0.85; p < 0.0001). CONCLUSION: We sought to quantify pre- and post-RT 18FDG-PET metrics of parotid glands in patients with OPC. Temporal dynamics of PET-derived metrics can potentially serve as MIBs of RT-related xerostomia in concert with clinical and dosimetric variables.

Evaluation of the Relative Citation Ratio, a New National Institutes of Health-Supported Bibliometric Measure of Research Productivity, among Academic Radiation Oncologists.

PURPOSE: Publication metrics are useful in evaluating academic faculty for awarding grants, recruitment, and promotion. A new metric, the relative citation ratio (RCR), was recently released by the National Institutes of Health (NIH); however, no benchmark data yet exist. We sought to create benchmark data for physician faculty in academic radiation oncology (RO) and analyze correlations associated with increased academic productivity. METHODS: Citation database searches were performed for all US radiation oncologists affiliated with academic RO programs. Gender, NIH funding, career duration, academic rank, RCR, and weighted RCR were collected for each faculty. RCR and weighted RCR were calculated and compared between each subgroup of interest. RCR percentiles were also created for reference. RESULTS: A total of 1,299 RO physician faculty members from 75 institutions were included in the analysis. Overall, RO physician were very productive and influential with a mean RCR of 1.57 ± 1.53 SD and median RCR (interquartile range) of 1.32 (0.87-1.94). Academic rank, career duration, and NIH funding were associated with increased mean RCR and weighted RCR. Male gender and having a PhD were associated with an increased weighted RCR but not an increased mean RCR. CONCLUSIONS: Current academic radiation oncologists have a high mean RCR value relative to the benchmark NIH RCR value of 1. All subgroups analyzed had an RCR value above 1 with professor or chair and previous NIH funding having the highest RCR and weighted RCR values overall. These data may be useful for self-evaluation of ROs as well as evaluation of faculty by institutional and departmental leaders.