Background We compared proton beam therapy (PBT) with intensity-modulated radiation therapy (IMRT) for pediatric craniopharyngioma in terms of disease control, cyst dynamics, and toxicity. Methods We reviewed records from 52 children treated with PBT (n=21) or IMRT (n=31) at two institutions in 1996−2012. Endpoints were overall survival (OS), disease control, cyst dynamics, and toxicity. Results At 59.6 months’ median follow-up ( PBT 33 mo vs. IMRT 106 mo, P < 0.001), the 3 year outcomes were 96% for OS, 95% for nodular failure-free survival (NFFS) and 76% for cystic failure-free survival (CFFS). Neither OS nor disease control differed between treatment groups (OS P=0.742; NFFS P=0.546; CFFS P=0.994). During therapy, 40% of patients had cyst growth (20% requiring intervention); immediately after therapy, 17 patients (33%) had cyst growth (transient in 14), more commonly in the IMRT group (42% vs. 19% PBT, P=0.082); and 27% experienced late cyst growth (32% IMRT, 19% PBT, P=0.353), with intervention required in 40%. Toxicity did not differ between groups. On multivariate analysis, cyst growth was related to visual and hypothalamic toxicity (P=0.009 and 0.04). Patients given radiation as salvage therapy (for recurrence) rather than adjuvant therapy had higher rates of visual and endocrine (P=0.017 and 0.024) dysfunction. Conclusions Survival and disease-control outcomes were equivalent for PBT and IMRT. Cyst growth is common, unpredictable, and should be followed during and after therapy, as it contributes to late toxicity. Delaying RT until recurrence may result in worse visual and endocrine function.

Introduction We investigated relationships between treatment characteristics and long-term outcomes in patients with locally advanced thymoma or thymic carcinoma. Methods We retrospectively reviewed 146 patients treated in 1980–2011 at two tertiary cancer care centers, 110 with Masaoka-Koga stage III–IVa invasive thymoma and 36 with stage I–IVa thymic carcinoma. Survival probabilities were estimated with the Kaplan-Meier method. Risk factors related to survival were identified by univariate and multivariate competing risk analysis, with overall survival (OS) as the competing risk. Cox regression analysis was used to identify risk factors for OS. Results Median follow-up time for all patients was 64 months. At 5/10 years, rates of OS and freedom from recurrence (FFR) were 81/58% and 81/65%, respectively. Of patients who underwent surgery, trimodality treatment produced better survival compared to less aggressive treatment among patients with stage III disease (p=0.03). Among patients who underwent trimodality treatment, patients with stage III disease had better OS (p=0.03) and FFR (p<0.001) than those with stage IVA disease. On Cox regression analysis, decreased OS was associated with thymic carcinoma (hazard ratio [HR]=7.36, 95% CI=2.38–22.77, p=0.001), R2/unresectable disease (HR=8.45, 95% CI=1.44–49.42, p=0.02) and an Eastern Cooperative Oncology Group performance score of 1 (HR=8.14, 95% CI=1.55–42.75, p=0.01) or 2–3 (HR=29.60, 95% CI=4.0–218.98, p=0.001) versus 0. Conclusion Aggressive treatment with chemotherapy, surgical resection, and postoperative radiation therapy can produce long-term survival for patients with invasive thymic malignanices.