K. Stang

Local control dependence on consecutive vs. nonconsecutive fractionation in lung stereotactic body radiation therapy

BACKGROUND Recent reports demonstrate impaired tumor re-oxygenation 24-48h after stereotactic body radiation therapy (SBRT), suggesting that non-consecutive treatment delivery may be advantageous. To test this hypothesis clinically, we compared local control in patients treated in consecutive daily fractions vs. nonconsecutive fractions. METHODS We retrospectively reviewed 107 lung SBRT patients (117 tumors) treated for T1-T2N0 NSCLC with LINAC based SBRT (50 or 60Gy/5fractions). Patients were characterized as having been treated in consecutive daily fractions vs. in non-consecutive fractions. Local control, survival and toxicity end points (CTCAE V4.0) were compared. Propensity score matching and Cox regression analyses were performed in order to determine the effect of fractionation on local control. RESULTS With a median follow up of 23.7months, 3-year local control was superior at 93.3% vs. 63.6% in the non-consecutive and consecutive group, respectively (p=0.001). Multivariate analysis and propensity score matching showed that consecutive fractionation was an independent predictor of local failure. Overall survival trended toward improvement in the non-consecutive group, but this was not statistically significant (p=0.188). Development of any grade 2 toxicity was not significantly different between the two groups (p=0.75). CONCLUSION Five-fraction SBRT delivered over non-consecutive days imparts superior LC and similar toxicity compared to consecutive fractionation. These results should be validated in independent datasets and in a prospective fashion.

Leukemia Cutis of the Face, Scalp, and Neck Treated with Non-coplanar Split Field Volumetric Modulated Arc Therapy: A Case Report

Malignancies with a superficial involvement of the scalp present a unique technical challenge for radiation treatment planning. As an example of this, leukemic infiltration of the superficial skin as the only presentation of the disease is a rare entity. For such cases, radiation oncologists have typically treated with 3D conformal radiotherapy with matched electron fields, a technique that can lead to significant dose inhomogeneity. In this report, we describe the case of a patient with leukemia cutis with a superficial involvement of the scalp, face, and shoulders that was treated with volumetric modulated arc radiotherapy, with an impressive clinical response.

The integration of radiation therapy and immunotherapy in melanoma management

Melanoma has long been considered an “immunologic” malignancy because of numerous reports of spontaneous regression as well as abscopal phenomena along with its relative responsiveness to cancer immunotherapy. Over the past few years, there has been a resurgence of interest in cancer immunotherapy with particular focus on melanoma. Many new immunotherapeutic interventions have arisen, some with notable clinical efficacy. One such example is the current generation of checkpoint inhibitors. In this article, we shall review the recent data on checkpoint inhibition in melanoma along with a brief review of other immunotherapeutic approaches, including the encouraging and expanding role of radiation therapy in integrated immunotherapy.

Predictors of Distant Failure After Stereotactic Body Radiation Therapy for Stages I to IIA Non–Small-Cell Lung Cancer

Purpose: The use of stereotactic body radiation therapy (SBRT) has emerged as an effective treatment modality for patients with early‐stage non–small‐cell lung cancer (NSCLC), with excellent local control rates. Despite this, there is a predominant pattern of distant failure. We sought to identify factors that help predict which patients with stages I to IIA NSCLC treated with SBRT are at highest risk of distant failure, so that we may utilize these factors in the future to help determine which patients may benefit from the addition of systemic therapies. Patients and Methods: We retrospectively reviewed 292 patients treated with SBRT for early stage NSCLC from 2006 to 2016 at 2 institutions. Patients were classified by T stage, tumor size, location and histology, pretreatment positron emission tomography/computed tomography (PET/CT) standardized uptake value (SUV), smoking status, and age. The primary endpoint of the study was distant failure. We aimed to analyze if patient characteristics could be identified that predicted for distant failure through the use of competing risk analysis. Results: The median follow‐up was 21.9 months. The median dose of radiation and fractionation delivered was 50 Gy (range, 45‐65 Gy) in 5 fractions (range, 3‐13 fractions). The median patient age was 72.8 years (interquartile range, 65.4‐79.7 years). The 2‐year distant failure was 22.0%, and overall survival at 2 years was found to be 61.0%. For every 1‐year increase in patient age, the hazard of distant failure at any given time was 3% lower (hazard ratio, 0.97; 95% confidence interval, 0.94‐0.99; P = .04). None of the remaining characteristics emerged as significant risk factors for distant failure on univariable or multivariable analysis. Conclusions: Overall, our cohort had distant failure and survival rates comparable with what has been described in the literature. Although we were unable to identify factors outside of age that correlated to risk of distant failure, this topic warrants further investigation, as distant failure is the primary pattern of failure with SBRT when used as the primary management for early‐stage NSCLC. Additional molecular studies are needed to further inform on the role of systemic therapy in patients with early‐stage NSCLC to improve clinical outcomes.