Ki Y, et al. J Korean Med Sci. 2014 Oct;29(10):1372-1378. http://dx.doi.org/10.3346/jkms.2014.29.10.1372

Ki Y, et al. J Korean Med Sci. 2017 May;32(5):757-763. https://doi.org/10.3346/jkms.2017.32.5.757

To evaluate the treatment outcomes of adjuvant external beam radiation therapy (EBRT) and vaginal brachytherapy (VB) following radical hysterectomy in cervical cancer patients with involved vaginal resection margin (VRM). Materials and. We retrospectively reviewed the medical records of 21 patients treated with postoperative EBRT and VB for positive VRM FIGO stage IB-IIA cervical cancer between 2003 and 2015. Concurrent platinum-based chemotherapy was administered to all patients. The median whole pelvis EBRT dose was 50.4 Gy (range, 45 to 50.4 Gy). In the VB, the median dose per fraction, number of fractions, and total dose delivered were: 4 Gy (range, 3.0 to 4.0 Gy), 4 fractions (range, 3 to 5 fractions), and 16 Gy (range, 12 to 20 Gy), respectively. At a median follow-up of 46 months (range, 9 to 122 months), local recurrence was observed in 2 patients, and distant metastasis was present in 7 patients. All patients with local recurrence subsequently developed distant metastases. The 5-year local control, disease-free survival, and overall survival rates were 89.1%, 65.9%, and 62.9%, respectively. Of the 21 patients, 7 patients (33.3%) reported grade 2 acute toxicity; however, there were no grade 3 or higher acute adverse events. Grade 1-2 late toxicities were observed in 8 patients. Late grade 3 urinary toxicity was reported in 1 patient. Conclusions: Adjuvant EBRT and VB showed excellent local control and low toxicity in cervical cancer patients with positive VRM. Although limited by its retrospective nature, the findings from our study provide evidence supporting the use of additional VB in pathologically involved VRM.

Background: To investigate risk factors for developing radiation-associated facial lymphedema (FL) in nasopharyngeal carcinoma (NPC) patients after concurrent chemoradiation (CCRT). Methods: Clinical data from 87 patients who underwent definitive CCRT for NPC in 2010–2018 was retrospectively evaluated. FL severity was graded using MD Anderson Cancer Center head and neck lymphedema rating scale. Logistic regression analysis was used to examine the factors associated with the presence of moderate/severe FL (grade ≥ 2). Results: At a median follow-up of 34 months (range, 18–96), 26/87 (29.9%) patients experienced grade ≥ 2 FL. A majority (84.6%) was experienced grade ≥ 2 FL 3–6 months after CCRT. Mean dose to the level IV, level I-VII neck node and N stage were significantly correlated with grade ≥ 2 FL at univariate analysis. At multivariate analysis, mean dose of level IV neck node (hazard ratio [HR], 1.238; 95% confidence interval [CI] = 1.084–1.414; p = 0.002) and level I-VII neck node (HR, 1.384; 95% CI = 1.121–1.708; p = 0.003) were independent predictors. Receiver Operating Characteristics (ROC) curve analysis showed that cut-off value of mean level IV neck node dose was 58.7 Gy (area under the curve [AUC] = 0.726; 95% CI = 0.614–0.839, p = 0.001) and mean level I-VII neck node dose was 58.6 Gy (AUC = 0.720; 95% CI = 0.614–0.826, p = 0.001) for grade ≥ 2 FL. Conclusions: Keeping mean dose to the level IV and level I-VII below 58.7 Gy and 58.6 Gy may reduce the likelihood of moderate/severe FL after CCRT for NPC.

The “oxygen effect” improves radiation efficacy; thus, tumor cell oxygen concentration is a crucial factor for improving lung cancer treatment. In the current study, we aimed to identify aerobic exercise-induced changes in oxygen concentrations in non-small cell lung cancer (NSCLC) cells. To this end, an NSCLC xenograft mouse model was established using human A549 cells. Animals were subsequently subjected to aerobic exercise and radiation three times per week for 2 weeks. Aerobic exercise was performed at a speed of 8.0 m/m for 30 min, and the tumor was irradiated with 2 Gy of 6 MV X-rays (total radiation dose 12 Gy). Combined aerobic exercise and radiation reduced NSCLC cell growth. In addition, the positive effect of aerobic exercise on radiation efficacy through oxygenation of tumor cells was confirmed based on hypoxia-inducible factor-1 and carbonic anhydrase IX expression. Finally, whole-transcriptome analysis revealed the key factors that induce oxygenation in NSCLC cells when aerobic exercise was combined with radiation. Taken together, these results indicate that aerobic exercise improves the effectiveness of radiation in the treatment of NSCLC. This preclinical study provides a basis for the clinical application of aerobic exercise to patients with NSCLC undergoing radiation therapy.

In volumetric modulated arc therapy (VMAT) planning, usually the collimator is rotated to minimize interleaf leakage and the tongue-and-groove effect. The objective of this study was to evaluate the effect of collimator angle on the dosimetric results of VMAT plans for patients with a locally-advanced nasopharyngeal carcinoma (LA-NPC). VMAT treatment planning sets were generated using the same planning parameters, but with different collimator angles for 11 LA-NPC patients. Each set was composed of 10 plans with collimator angles at 0, 5, 10, 15, 20, 25, 35, 40, and 45 degrees. Dosimetric parameters, such as target coverage, organs at risk (OAR), and dose conformity, were analyzed at various collimator angles. With increasing collimator angles, the absorbed doses to the optic apparatus were increased by up to 35% comparing to that at a collimator angle of 0°. The best value of the conformity index (CI) was 0.971 ± 0.023 at collimator angles of 20° and 30°. The worst value of CI was 0.917 ± 0.051 at a collimator angle of 0°. The homogeneity index (HI)₉₅ and HI₉₈ had the best values of 0.106 ± 0.040 and 0.079 ± 0.031, respectively, at a collimator angle of 25°. The worst values of HI₉₅ and HI₉₈ were 0.136 ± 0.039 and 0.105 ± 0.032, respectively, at a collimator angle of of 0°. The maximum doses for some OARs (body, ear, parotid gland, mandible, and brainstem) and the HI did not show any statistically significant differences. However, the mean doses had positive correlations (r = 0.449 ~ 0.773, p<0.001) with the irradiated volume. The CI had a weak positive correlation (r = 0.316, p<0.001) with the irradiated volume. Other comparison parameters were evaluated as functions of the collimator angle. These findings will give useful information for choosing the collimator angle in VMAT plans for patients with a LA-NPC.