Is severe emphysema, as defined by quantitative CT measurement, a negative risk factor of radiation fibrosis?

OBJECTIVE: To investigate whether patients with emphysema, as evaluated by quantitative CT image measurement, are at risk of developing radiation pneumonitis (RP) after radiotherapy (RT) for non-small cell lung cancer (NSCLC). METHODS: Between March 2011 and June 2015, 68 consecutive patients with Stage I NSCLC treated with a RT dose of 75 Gy given in 30 fractions were enrolled. The median age was 79 years and there were 45 males and 23 females. The number of patients with T1 and T2 were 49 and 19, respectively. The severity of emphysema was evaluated by the percentages of the low attenuation area (LAA) of ≤-860 or -950 Hounsfield unit (HU) and average HU in the whole lung. RESULTS: The mean difference percentages of LAA of ≤-860 (p = 0.0004) or -950 HU (p = 0.005) and average HU (p = 0.001) in patients with RP were significantly lower than those in patients without RP. The area under curve (AUC) of average HU was significantly higher than AUC of LAA of ≤-860 (p < 0.0001) or -950 HU (p < 0.0001). The RP rate after RT was significantly lower when the average HU values were ≤-850 HU (p = 0.0003). CONCLUSION: Patients with emphysema evaluated by average HU (≤-850 HU) in the whole lung were found to be at low risk of RP after RT. Advances in Knowledge: Quantitative measurement of average HU from CT images was predicted of RP after RT.

Target volume dose and clinical outcome in radiotherapy for primary marginal zone lymphoma of the ocular adnexa.

The aim of the present study was to determine the optimal dose and optimal target volume for marginal zone lymphoma of the ocular adnexa. Between January, 2008 and December, 2013, 40 patients with histologically proven primary marginal zone lymphoma of the ocular adnexa who underwent radiotherapy at the Tokyo Medical University were evaluated. The prescribed dose was 30 Gy in 15 fractions to the iso-center. Doses to the gross tumor volume (GTV), conjunctiva, bulbus oculi, retina and retrobulbar space were investigated, and the association between dose-volume factors and clinical outcome was analyzed. The overall and local progression-free survival rates at 3 and 5 years were 100% during a median observation period of 32 months. Two patients relapsed in the contralateral ocular adnexa. The progression-free survival rates at 3 and 5 years were 100 and 93.3%, respectively. The mean dose was 2.0 and 1.9 Gy for targets receiving 95% of the GTV dose (D95). The minimum dose was 0.9-2.0 Gy (median, 1.8 Gy). Thus, primary marginal zone lymphoma of the ocular adnexa favorably responded to lower doses of radiation, compared with prescribed doses to the iso-center. A radiation dose of 27 Gy in 15 fractions at D95 of GTV appeared to be optimal.

Feasibility of intensity-modulated radiotherapy combined with gemcitabine and S-1 for patients with pancreatic cancer.

The aim of the present study was to establish whether intensity-modulated radiotherapy (IMRT) with concurrent gemcitabine and S-1 is a feasible treatment option for patients with locally advanced pancreatic ductal adenocarcinoma. Patients with pancreatic ductal adenocarcinoma were prospectively enrolled. An IMRT dose of 50.4 Gy in 28 fractions with concurrent gemcitabine at a dose of 600 mg/m2 and S-1 at a dose of 60 mg were administrated. Adverse events and associated dosimetric factors were assessed. Between February 2012 and January 2014, 17 patients with borderline resectable and 4 with unresectable pancreatic cancer were enrolled. None of the patients experienced grade 3 or worse nausea and vomiting. The planning target volume (≥200 vs. <200 ml) was a statistically significant predictive factor for neutrocytopenia (≥500 vs. 500/µl, P=0.02). Concurrent IMRT with gemcitabine and S-1 for patients with locally advanced pancreatic cancer is feasible, with tolerable hematological toxicities and low gastrointestinal toxicities.