The omission of intentional primary site radiation following transoral robotic surgery in 59 patients: No local-regional failures.

BACKGROUND: We assessed locoregional control with omission of intentional primary site radiation after transoral robotic surgery (TORS) and quantified nontargeted primary site dose. METHODS: Following Institutional Review Board (IRB) approval, patients treated with primary TORS resection for squamous cell carcinomas of the oropharynx were reviewed. Patients with cT1-2 tumors, >2 mm margins, in whom the surgeon resected the primary without revising specimen-driven margins, qualified for omission of primary site radiation. RESULTS: From 2014 to 2019, 112 patients met criteria. Fifty-nine (52%) patients did not receive radiation targeting the primary site; of whom, 22 received no radiation. In this group, there were no local failures; mean age was 58 years and median follow-up was 25 months. Thirty-seven patients received adjuvant radiation targeting the neck, mean bystander dose to the primary site was 28.8 Gy (range, 13.3-50.6 Gy). CONCLUSION: In a 59 patient population, omission of radiation to the primary site after TORS resulted in no locoregional failures.

Fine-tuning the normal tissue objective in eclipse for lung stereotactic body radiation therapy.

The purpose of this study was to characterize the effects of the normal tissue objective (NTO) on lung stereotactic body radiation therapy (SBRT) dose distributions. The NTO is a spatially varying constraint used in Eclipse to limit dose to normal tissues by steepening the dose gradient. However, the multitude of potential NTO setting combinations challenges optimal NTO tuning. In the present study, a broad range of NTO settings are investigated for lung SBRT treatment planning with volumetric modulated arc therapy(VMAT). Ten prior lung SBRT cases were replanned using NTO priorities of 1, 50, 100, 200, 500, and 999 in combination with fall-off values of 0.01, 0.05, 0.10, 0.15, 0.20, 0.30, 0.50, 1.00, and 5.00 mm-1 and the automatic NTO. NTO distances to planning target volume (PTV), start dose, and end dose were 1 mm, 100%, and 10%, respectively, for all 600 plans. Prescription dose covered 95% of the PTV. The following metrics were recorded: conformity index (CI), ratio of the 50% prescription isodose volume to PTV (R50%), maximum dose 2 cm away from PTV (D2cm), lung volume of ≥20 Gy (V20Gy), maximum PTV dose (PTVmax), and monitor units (MUs). Differences between prior plans and NTO plans were evaluated using the Wilcoxon signed-rank test. Different combinations of NTO settings resulted in wide-ranging plan quality metrics: CI (1.00 to 1.54), R50% (3.95 to 7.57), D2cm (33.4% to 67.9%), V20Gy (1.66% to 2.75%), MU (1.81 cGy-1 to 4.69 cGy-1), and PTVmax (118% to 175%). Although no settings were optimal for all metrics, a fall-off of 0.15 mm-1 and a priority of 500 best satisfied institutional criteria. Compared with prior plans, NTO plans resulted in significantly lower R50% (4.00 vs 4.35, p = 0.002), lower V20Gy (1.22% vs 1.32%, p = 0.006), and higher PTVmax (138% vs 122%, p = 0.002). All of the prior and well-tuned NTO plans met Radiation Therapy Oncology Group (RTOG) 0813 guidelines. Lung SBRT dose distributions were characterized across a range of NTO settings. NTO plans with well-tuned settings compared favorably with prior plans.

Correlations Between Macular, Skin, and Serum Carotenoids.

Purpose: Ocular and systemic measurement and imaging of the macular carotenoids lutein and zeaxanthin have been employed extensively as potential biomarkers of AMD risk. In this study, we systematically compare dual wavelength retinal autofluorescence imaging (AFI) of macular pigment with skin resonance Raman spectroscopy (RRS) and serum carotenoid levels in a clinic-based population. Methods: Eighty-eight patients were recruited from retina and general ophthalmology practices from a tertiary referral center and excluded only if they did not have all three modalities tested, had a diagnosis of macular telangiectasia (MacTel) or Stargardt disease, or had poor AFI image quality. Skin, macular, and serum carotenoid levels were measured by RRS, AFI, and HPLC, respectively. Results: Skin RRS measurements and serum zeaxanthin concentrations correlated most strongly with AFI macular pigment volume under the curve (MPVUC) measurements up to 9° eccentricity relative to MPVUC or rotationally averaged macular pigment optical density (MPOD) measurements at smaller eccentricities. These measurements were reproducible and not significantly affected by cataracts. We also found that these techniques could readily identify subjects taking oral carotenoid-containing supplements. Conclusions: Larger macular pigment volume AFI and skin RRS measurements are noninvasive, objective, and reliable methods to assess ocular and systemic carotenoid levels. They are an attractive alternative to psychophysical and optical methods that measure MPOD at a limited number of eccentricities. Consequently, skin RRS and MPVUC at 9° are both reasonable biomarkers of macular carotenoid status that could be readily adapted to research and clinical settings.