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Introduction Patients treated with stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) are subject to locoregional and distant recurrence, as well as the formation of second primary lung cancers (SPLC). The optimal surveillance regimen for patients treated with SBRT for early-stage NSCLC remains unclear, and herein we investigated the post-treatment recurrence patterns and development of SPLC. Methods Three-hundred and sixty-six patients with pathologically proven inoperable early-stage NSCLC treated with SBRT between 2006 and 2013 were assessed. Patients underwent a CT scan of the chest every 3 months during years 1 and 2, every 6 months during years 3 and 4, and annually thereafter. Competing risks analysis was used for all time-to-event analyses. Results With a median follow up of 23 months, the 2-year cumulative incidence of local, nodal and distant failures were 12.2%, 16.1%, and 15.5%, respectively. Of patients with disease progression post-SBRT (n=108), 84% (n=91) occurred within the first two years. Five percent (n=19) of patients developed a SPLC. The median time to development of SPLC was 16.5 months (range 6.5 to 71.1 months), with 33% (n=6) of these patients developing SPLCs after two years. None of the never smokers, but 4% of former and 15% of current tobacco smokers developed a SPLC (p=0.005). Conclusion Close monitoring with routine CT scans within the first 2 years after SBRT is effective in detecting early disease progression. In contrast, the risk for developing a SPLC remains elevated beyond 2 years, particularly in former and current smokers.

Purpose Beam gating with deep inspiration breath hold (DIBH) has been widely used for motion management in radiotherapy. Normally it relies on some external surrogate for estimating the internal target motion, while the exact internal motion is unknown. In this study, we used the intrafraction motion review (IMR) application to directly track an internal target and characterized the residual motion during DIBH treatment for pancreatic cancer patients through their full treatment courses. Methods and Materials Eight patients with pancreatic cancer treated with DIBH volumetric modulated arc therapy in 2017 and 2018 were selected for this study, each with some radiopaque markers (fiducial or surgical clips) implanted near or inside the target. The Varian Real‐time Position Management (RPM) system was used to monitor the breath hold, represented by the anterior‐posterior displacement of an external surrogate, namely reflective markers mounted on a plastic block placed on the patient's abdomen. Before each treatment, a cone beam computed tomography (CBCT) scan under DIBH was acquired for patient setup. For scan and treatment, the breath hold reported by RPM had to lie within a 3 mm window. IMR kV images were taken every 20° or 40° gantry rotation during dose delivery, resulting in over 5000 images for the cohort. The internal markers were manually identified in the IMR images. The residual motion amplitudes of the markers as well as the displacement from their initial positions located in the setup CBCT images were analyzed. Results Even though the external markers indicated that the respiratory motion was within 3 mm in DIBH treatment, significant residual internal target motion was observed for some patients. The range of average motion was from 3.4 to 7.9 mm, with standard deviation ranging from 1.2 to 3.5 mm. For all patients, the target residual motions seemed to be random with mean positions around their initial setup positions. Therefore, the absolute target displacement relative to the initial position was small during DIBH treatment, with the mean and the standard deviation 0.6 and 2.9 mm, respectively. Conclusions Internal target motion may differ from external surrogate motion in DIBH treatment. Radiographic verification of target position at the beginning and during each fraction is necessary for precise RT delivery. IMR can serve as a useful tool to directly monitor the internal target motion.

Background: Multi-beam IMRT enhances the therapeutic index by increasing the dosimetric coverage of the targeted tumor tissues while minimizing volumes of adjacent organs receiving high doses of RT. The tradeoff is that a greater volume of lung is exposed to low doses of RT, raising concern about the risk of radiation pneumonitis (RP).Methods: Between 7/2010-1/2013, patients with node-positive breast cancer received inverseplanned, multibeam IMRT to the breast/chest wall and regional nodes including the internal mammary nodes (IMN). The primary endpoint was feasibility, predefined by dosimetric treatment planning criteria. Secondary endpoints included the incidence of ≥ grade 3 RP and changes in pulmonary function measured by CTCAE v3.0 scales, pulmonary function tests (PFTs) and

Background To evaluate the efficacy and tolerability of the addition of two monoclonal antibodies, bevacizumab and cetuximab, to two cycles of high-dose cisplatin administered concurrently with IMRT for HNSCC. Methods Patients with newly diagnosed stage III/IVB (M0) HNSCC received cetuximab (400 mg/m2 loading dose, followed by 250 mg/m2 weekly), bevacizumab (15 mg/kg, days 1 and 22), and cisplatin (50 mg/m2, days 1, 2, 22, and 23) concurrently with IMRT (70 Gy). The primary endpoint was progression free survival (PFS). Secondary endpoints were overall survival (OS) and safety and tolerability. Results Among 30 patients enrolled, the primary tumor site was oropharynx in 25 patients (p16 immunohistochemistry was positive in 17, negative in 1, and not done in 6 of the oropharynx tumors). Median age was 57 years (range, 38–77 years) and 27 patients had clinical stage IVA disease. All patients completed the full planned dose of radiation therapy. The most common ≥ grade 3 adverse events were lymphopenia, mucositis (functional), and dysphagia. With a median follow up of 33.8 months, 2 year PFS was 88.5% (95% CI, 68.1–96.1) and 2 year OS was 92.8% (95% CI, 74.2–98.1%) Conclusion The addition of bevacizumab and cetuximab to two cycles of cisplatin, given concurrently with IMRT, was well tolerated and was associated with favorable efficacy outcomes in this patient population.