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BackgroundChemoradiotherapy (CRT) and bio-radiotherapy (BRT) are recognized as standard therapies for head and neck cancer (HNC). Aspiration pneumonia after CRT or BRT is a common late adverse event. Our aim in this study was to evaluate the cause-specific incidence of aspiration pneumonia after CRT or BRT and to identify its clinical risk factors.MethodsWe performed a retrospective analysis of 305 patients with locally advanced HNC treated by CRT or BRT between August 2006 and April 2015.ResultsOf these 305 patients, 65 (21.3%) developed aspiration pneumonia after treatment. The median onset was 161 days after treatment. The two-year cause-specific cumulative incidence by CRT or BRT was 21.0%. Multivariate analysis revealed five independent risk factors for aspiration pneumonia, namely, habitual alcoholic consumption, use of sleeping pills at the end of treatment, poor oral hygiene, hypoalbuminemia before treatment, and the coexistence of other malignancies. A predictive model using these risk factors and treatment efficacy was constructed, dividing patients into low- (0–2 predictive factors), moderate- (3–4 factors), and high-risk groups (5–6 factors), the two-year cumulative incidences of aspiration pneumonia of which were 3.0, 41.6, and 77.3%, respectively. Aspiration pneumonia tended to be associated with increased risk of death, although this was not statistically significant (multivariate-adjusted hazard ratio 1.39, P = 0.18).ConclusionThe cause-specific incidence and clinical risk factors for aspiration pneumonia after definitive CRT or BRT were investigated in patients with locally advanced HNC. Our predictive model may be useful for identifying patients at high risk for aspiration pneumonia.

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UMIN000016453.

We have successfully created a single arc volumetric modulated arc therapy (VMAT) plan for treating post-surgical left breast/chest wall and regional nodes using Elekta multileaf collimator (MLC). Dose volume histograms (DVHs) were compared between the VMAT plans and conventional tangential beam plans using a field-in-field technique, leading to significant DVH advantages in the VMAT plans. The difference between Elekta VMAT and Varian RapidArc due to different MLC designs was discussed in terms of the number of arcs required to cover a large target, highlighting a single arc capability of Elekta VMAT for a large target volume which may be less sensitive to unexpected organ motion during dose delivery.

We conducted a retrospective, nationwide multicenter study to evaluate the clinical outcomes of proton beam therapy for bone sarcomas of the skull base and spine in Japan. Eligibility criteria included: (i) histologically proven bone sarcomas of the skull base or spine; (ii) no metastases; (iii) ≥20 years of age; and (iv) no prior treatment with radiotherapy. Of the 103 patients treated between January 2004 and January 2012, we retrospectively analyzed data from 96 patients who were followed‐up for >6 months or had died within 6 months. Seventy‐two patients (75.0%) had chordoma, 20 patients (20.8%) had chondrosarcoma, and four patients (7.2%) had osteosarcoma. The most frequent tumor locations included the skull base in 68 patients (70.8%) and the sacral spine in 13 patients (13.5%). Patients received a median total dose of 70.0 Gy (relative biological effectiveness). The median follow‐up was 52.6 (range, 6.3–131.9) months. The 5‐year overall survival, progression‐free survival, and local control rates were 75.3%, 49.6%, and 71.1%, respectively. Performance status was a significant factor for overall survival and progression‐free survival, whilst sex was a significant factor for local control. Acute Grade 3 and late toxicities of ≥Grade 3 were observed in nine patients (9.4%) each (late Grade 4 toxicities [n = 3 patients; 3.1%]). No treatment‐related deaths occurred. Proton beam therapy is safe and effective for the treatment of bone sarcomas of the skull base and spine in Japan. However, larger prospective studies with a longer follow‐up are warranted.

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BackgroundRe-irradiation (re-RT) of the thorax is challenging due to the impact of prior therapies on normal tissues, and there are few reports of definitive re-RT. The treatment toxicities and efficacy of re-RT are not well known. The aim of the present study was to assess the safety and efficacy of definitive re-RT of the thorax.MethodsPatients who were treated with thoracic re-RT between March 2007 and December 2014 were retrospectively analyzed. Primary and re-irradiation plans were required to have an overlap of dose distributions for the 80 % isodose level. All doses were recalculated to an equivalent dose of 2 Gy per fraction (EQD2). When possible, analysis of dose accumulation was carried out using the medical image merge (MIM) (®) software program (version 6.5, MIM Software Inc., Cleveland, OH). Administration dosages for organs at risk were defined.ResultsFourteen (67 %) and seven (33 %) patients with non-small cell carcinoma (NSCLC) and small cell carcinoma (SCLC), respectively, were identified. The patients’ median age was 72 (range 53–85) years. Fifteen patients (71 %) had “proximal” tumors, defined as tumors at the distal 2 cm of the trachea, carina, and main bronchi. The median interval from initial RT to re-RT was 26.8 (range 11.4–92.3) months. Re-RT was delivered by X-ray beam and proton beam therapy in 20 (95 %) patients and 1 (5 %) patient, respectively. The median radiation dose of re-RT was 60 (range 54–87.5) Gy10 and 50 (range 50.0–87.5) Gy10 for patients with NSCLC and SCLC, respectively. Grade 3 acute radiation pneumonitis occurred in only one patient. There were no other serious complications. The median follow-up time was 22.1 (range 2.3–56.4) months. The median local progression-free survival time (LPFS) and overall survival time (OS) were 12.9 (95 % confidence interval (CI): 8.9–27.9) months and 31.4 (95 % CI: 16.9–45.9) months, respectively. Patients receiving ≥ 60 Gy10 at re-RT had longer LPFS (p = 0.04).ConclusionsGood safety with longer OS than in previous reports was demonstrated. Re-RT seems to be a promising treatment option. Further study to define the risk-benefit ratios is necessary.