Radiation therapy (RT) for a left-sided breast cancer often involves some incidental exposure of the heart and increase in the rate of major coronary events. One method to reduce the dose to the heart during a tangential breast irradiation is the deep inspiration breath hold (DIBH) technique. Our department adopted DIBH for selected left breast cancer patients with a maximum cardiac distance ≥ 10 mm. We evaluated the effect of the DIBH on cardiac dose compared to normal free breathing (FB). The secondary objective of our present study was to use modeled risk estimates to quantify the risk of coronary events after RT with DIBH. Thirty-two patients who underwent RT with DIBH at our hospital were retrospectively analyzed. For each patient, two computed tomography (CT) scans were acquired, FB-CT and DIBH-CT. Using a deformable image registration tool, the target volume was deformed from DIBH-CT to FB-CT, and conventional tangential treatment planning was performed, focusing on the equality of target coverage between the two plans. Doses to the heart, left anterior descending (LAD) artery, and ipsilateral lung were assessed. By using DIBH, the average mean heart dose was reduced from 724.1 cGy to 279.3 (p < 0.001). The relative heart volume irradiated with 10 Gy–50 Gy was consistently reduced. The mean dose to the LAD coronary artery was reduced from 4079.1 cGy to 2368.9 cGy (p < 0.001). The ipsilateral lung volume receiving 20 Gy or more and 40 Gy or more was reduced by 2.2 % in both cases. Estimated risks of coronary events at 10 years were 4.03 and 2.55 % for RT with FB and DIBH, respectively (p < 0.001). The use of DIBH during RT of the left-sided breast considerably reduces the doses delivered to the heart and LAD artery with similar target coverage. For the current study patients, the probability of major coronary events was reduced with DIBH.

Objective: The aim of the present study was to evaluate prognostic values of pre-treatment fluorine-18 fludeoxyglucose (18F-FDG) positron emission tomography (PET) parameters for predicting the distant metastasis (DM) of nasopharyngeal cancer. Methods: 73 patients diagnosed with nasopharyngeal cancer with regional lymph node (LN) involvement, who underwent pre-treatment 18F-FDG PET evaluation between January 2005 and December 2012, were retrospectively reviewed. We assessed the 18F-FDG PET parameters of the primary tumours (T–) and regional LNs (N–). For patients with bilateral retropharyngeal, bilateral neck and/or supraclavicular LN involvement, we also assessed the 18F-FDG PET parameters of the farthest LN station [N(f)–]. The following 18F-FDG PET parameters were evaluated: maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), peak standardized uptake value (SUVpeak), metabolic tumour volumes (MTVs) (MTV30–MTV70, which were calculated as the tumour volume with 30%, 40%, 50%, 60% and 70% of the SUVmax as the threshold, respectively) and total lesion glycolysis (TLG) (TLG30–TLG70, which were determined by the product of each MTV and the corresponding SUVmean within that MTV). Distant metastasis-free survival (DMFS) rates were estimated from the date of the start of radiotherapy to the date of DM or last follow-up by the Kaplan–Meier method. Univariate and multivariate analyses were performed to identify prognostic factors for DMFS. The median follow-up period was 53 months (range 12–110 months). Results: Most patients (95%) received concurrent chemoradiotherapy. The major failure pattern was DM (15 of all patients, 21%) and the 5-year DMFS was 79%. In univariate analysis, the T–SUVmax, T–SUVmean, T–SUVpeak, N–SUVmax, N–SUVpeak, N(f)–SUVmax and N(f)–SUVpeak were significant prognostic factors for DMFS. In multivariate analysis, the T–SUVmax, T–SUVpeak, N(f)–SUVmax and N(f)–SUVpeak were significant prognostic factors for DMFS. Of these parameters, the N(f)–SUVmax (hazard ratio = 6.524; p = 0.001) and N(f)–SUVpeak (hazard ratio = 5.399; p = 0.001) were the strongest prognostic factors for DMFS. Conclusion: In patients with nasopharyngeal cancer with LN involvement, the standardized uptake value parameter of the farthest LN station seems to be an important 18F-FDG PET parameter for predicting DM. Further studies are needed to validate its clinical significance. Advances in knowledge: We found that pre-treatment 18F-FDG PET parameters of primary tumours and regional LNs (the SUVmax and SUVpeak of the primary tumour and the farthest LN station) were significant prognostic factors for DMFS in patients with nasopharyngeal carcinoma with LN involvement.

Elderly patients with non-small cell lung cancer (NSCLC) are frequently treated with radiation therapy (RT) alone, due to poor performance status or underlying disease. We investigated the effectiveness of RT over 60 Gy administered alone to NSCLC patients who were unfit or rejecting for combination treatment. From April 2002 to July 2010, 83 patients with stage II-III NSCLC, aged over 60 years, treated by RT alone with a curative aim were analyzed. Radiation was targeted to the primary tumor and clinically involved lymph nodes. A total dose of 66 Gy in 30 fractions (2.2 Gy/fraction) was delivered once daily (5 fractions weekly). One month after completing RT, initial tumor responses were evaluated. Median age of patients was 73 years (range, 60 – 82 years). The median survival time was 18.6 months (range, 2–135). The actuarial overall survival rates at 2 and 3 years were 39 % and 23 %, and cause-specific survival rate at 2 and 3 years were 57 % and 47 %, respectively. When primary tumor was controlled, the 2- and 3-year CSS were 56 % and 45 %, but 32 % and 23 % in those patients with local failure, respectively (P = 0.017). Additionally, the local control rate was associated with the initial tumor response (P = 0.01). No patient experienced grade 4+ toxicity. For stage II-III NSCLC patients aged over 60 years and unfit or rejecting for combination treatment, RT alone showed promising result. Long-term disease control can be expected if an early tumor response to radiation is achieved, which could result in improved overall survival rates.

This Korean population-based study aimed to describe the patterns of hypothyroidism after adjuvant radiation therapy (RT) in patients with breast cancer. The Korean Health Insurance Review and Assessment Service database was searched for patients with invasive breast carcinomas. We calculated the cumulative incidence and incidence rates per 1,000 person-years of subsequent hypothyroidism and compared them using the log-rank test and the Cox proportional hazards model. Between 2007 and 2018, 117,135 women diagnosed with breast cancer with a median follow-up time of 4.6 years were identified. The 8-year incidence of hypothyroidism was 9.3% in patients treated with radiation and 8.6% in those treated without radiation (p = 0.002). The incidence rates per 1,000 person-years in the corresponding treatment groups were 6.2 and 5.7 cases, respectively. The hazard ratio (HR) in patients receiving RT was 1.081 (95% confidence interval [CI], 1.013–1.134; p = 0.002). After mastectomy, RT showed a trend toward a higher risk of hypothyroidism (HR = 1.248; 95% CI, 0.977–1.595; p = 0.076). Our study provides one of the largest population-based data analyses regarding the risk of hypothyroidism among Korean patients with breast cancer. The adjusted risk for patients treated with RT exceeded that for patients with breast cancer treated without RT. The effect was evident immediately after treatment and lasted up to approximately 9 years.

Introduction: We evaluated the radiologic response rate of combined transarterial chemoembolization (TACE) plus radiotherapy (RT) in treatment-naïve patients with liver-confined hepatocellular carcinoma (HCC) with macroscopic vascular invasion (MVI) and analyzed its clinical importance in overall survival (OS) outcomes. Methods: Patients who were treated with TACE plus RT as a first-line treatment for HCC with MVI between January 2010 and December 2015 were retrospectively reviewed. Radiologic response was assessed according to the modified Response Evaluation Criteria in Solid Tumors (mRECIST) at 2 and 4 months after completion of RT. Landmark analysis at 2 and 4 months, and time-dependent Cox regression analysis using response as a time-dependent covariate were performed for univariable and multivariable analyses. Results: The 2-month landmark analysis included 427 patients, and the 4-month landmark analysis included 355 patients after excluding patients without imaging studies for response evaluation at 4 months. Radiologic responses were observed in 210 (49.2%) patients at 2 months and 181 (51.8%) patients at 4 months. In multivariable analyses, radiologic response was identified as an independent prognosticator for OS at 2 months (median OS: responders, 23.1 months vs. nonresponders, 8.0 months; hazard ratio [HR], 3.194; p < 0.001) and 4 months (median OS: responders, 26.5 months vs. nonresponders, 9.3 months; HR, 4.534; p < 0.001). Conclusion: Radiologic response assessed by mRECIST was a significant prognostic factor for OS in patients with advanced-stage HCC showing MVI treated with combined TACE plus RT.