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Background. Three nomogram models for early stage uterine cervical cancer have been developed (KROG 13-03 for overall survival [OS], SNUH/AMC for disease-free survival [DFS], and KROG 12-08 for distant metastases-free survival [DMFS]) after radical hysterectomy (RH) and pelvic lymph node dissection (PLND). This study aimed to validate these models using our cohort with adjuvant radiotherapy. Methods. According to the eligibility criteria of nomogram studies, patients were enrolled in Group A (N=109) for the two KROG models (RH with PLND and whole pelvic irradiation) and Group B (N=101) for the SNUH/AMC model (RH with PLND and squamous histology). Using Cox-regression hazard models, the prognostic factors of our cohorts were evaluated. The risk probabilities induced from published nomogram scores were calculated and the concordance indices were evaluated. Results. Group A had 88.1% 5-year OS and 86.0% 5-year DMFS. Group B had 83.0% 5-year DFS. In multivariate analyses, large tumor size for OS (HR 8.62, P<0.001) and DMFS (HR 5.13, P=0.003), young age (≤40 versus 41–64 years) for OS (HR 4.63, P=0.097) and DFS (HR 3.44, P=0.051), and multiple lymph node metastases (0 versus ≥3) for DMFS (HR 4.03, P=0.031) and DFS (HR 3.90, P=0.038) were significantly correlated. The concordance indices for OS, DMFS, and DFS were 0.612 (P=0.002), 0.597 (P=0.014), and 0.587 (P=0.020), respectively. Conclusion. The developed nomogram models after RH and PLND are clinically useful in predicting various types of survival with significance.

Skin reaction is major problem during whole breast radiotherapy. To identify factors related to skin reactions during whole breast radiotherapy, various personal, clinical, and radiation dosimetric parameters were evaluated. From January 2012 to December 2013, a total of 125 patients who underwent breast conserving surgery and adjuvant whole breast irradiation were retrospectively reviewed. All patients had both whole breast irradiation and boost to the tumour bed. Skin reaction was measured on the first day of boost therapy based on photography of the radiation field and medical records. For each area of axilla and inferior fold, the intensity score of erythema (score 1 to 5) and extent (score 0 to 1) were summed. The relationship of various parameters to skin reaction was evaluated using chi-square and linear regression tests. TheV100(volume receiving 100% of prescribed radiation dose,p<0.001, both axilla and inferior fold) and age (p=0.039for axilla and 0.026 for inferior fold) were significant parameters in multivariate analyses. The calculated axilla dose (p=0.003) and breast separation (p=0.036) were also risk factors for axilla and inferior fold, respectively. Young age and largeV100are significant factors for acute skin reaction that can be simply and cost-effectively measured.

Purpose. To investigate the effectiveness of respiratory guidance system in 4-dimensional computed tomography (4DCT) based respiratory-gated radiation therapy (RGRT) by comparing respiratory signals and dosimetric analysis of treatment plans.Methods. The respiratory amplitude and period of the free, the audio device-guided, and the complex system-guided breathing were evaluated in eleven patients with lung or liver cancers. The dosimetric parameters were assessed by comparing free breathing CT plan and 4DCT-based 30–70% maximal intensity projection (MIP) plan.Results. The use of complex system-guided breathing showed significantly less variation in respiratory amplitude and period compared to the free or audio-guided breathing regarding the root mean square errors (RMSE) of full inspiration (P=0.031), full expiration (P=0.007), and period (P=0.007). The dosimetric parameters includingV5 Gy,V10 Gy,V20 Gy,V30 Gy,V40 Gy, andV50 Gyof normal liver or lung in 4DCT MIP plan were superior over free breathing CT plan.Conclusions. The reproducibility and regularity of respiratory amplitude and period were significantly improved with the complex system-guided breathing compared to the free or the audio-guided breathing. In addition, the treatment plan based on the 4D CT-based MIP images acquired with the complex system guided breathing showed better normal tissue sparing than that on the free breathing CT.