Disease severity-based evaluation of utility weights for lung cancer-related health states in Korea.

BACKGROUND: Utility weight, a measure of health-related quality of life, is used in disease burden measurements and economic evaluations. In this study, we used the visual analogue scale (VAS) and standard gamble (SG) method to determine the utility weights of lung cancer health states in South Korea from a societal perspective. METHODS: Six hypothetical health states for lung cancer or a related health state reflective of disease severity were developed: 1) Stage I, 2) Stage II, 3) Stage IIIa, 4) Stage IIIB, 5) Stage IV, and 6) Pulmonary nodule. The description of each health state description was divided into four parts: diagnosis, symptoms, treatment, and progression and prognosis. A total of 515 representative adult Korean participants used a VAS and SG to evaluate these six health states via face-to-face computer-assisted interviews. The means, standard deviations, and median utility weights of the six health states were estimated by valuation method. RESULTS: The two valuation methods of the scenarios yielded the same mean utility rankings. Pulmonary nodule received the highest rank (VAS, 0.66 and SG, 0.83), whereas Stage 4 was assigned the lowest rank (VAS, 0.09 and SG, 0.31). For all health states, the mean utility weights calculated using the SG were greater than those calculated using the VAS. The differences between the utility weights obtained using the two valuation methods ranged from 0.14 (Stage I) to 0.22 (Stage IV). The two approaches tended to yield larger differences for more severe stages. CONCLUSIONS: This study determined utilities for squamous cell lung cancer that will be useful for estimating the burden of lung cancer and for conducting economic evaluations of lung cancer interventions.

Novel management of expected post-radiotherapy complications in hepatocellular carcinoma patients: a case report.

In recent years, radiotherapy (RT) has been used to treat hepatocellular carcinoma (HCC) at each stage. This clinical trend has developed with the increasing improvement of RT techniques, which show clinical results comparable to those of other treatment modalities. Intensity-modulated radiotherapy uses a high radiation dose to improve treatment effectiveness. However, the associated radiation toxicity can damage adjacent organs. Radiation-induced gastric damage with gastric ulcers is a complication of RT. This report presents a novel management strategy for preventing post-RT gastric ulcers. We present the case of a 53-year-old male patient diagnosed with HCC, who experienced gastric ulcer after RT. Before the second round of RT, the patient was administered a gas-foaming agent, which was effective in preventing RT complications.

Stump rotation in a nerve autograft by 2 factors: cross-connection and difference in diameter.

The aim of this study was to determine the influence of stump rotation (fascicular cross-connection) on nerve autograft functional recovery. Thirty rat sciatic nerves were transected and repaired by autograft. The rats were divided into 3 groups according to the number of stump rotations of the autograft: (1) plain graft (PG-g, with no change in fascicular orientation, no difference in diameter), (2) graft rotation (GR-g, with no change in fascicular orientation, and diameter difference between fascicles), (3) stump rotation (SR-g, with cross-connection and diameter difference between fascicles). Relative gastrocnemius muscle weight and nerve fiber count were examined as anatomic recovery indices, and autotomy score (ATS) and toe-out angle as functional recovery indices. The results showed that SR-g had a significantly low functional recovery compared with PG-g and GR-g. However, there was no difference found in the anatomic recovery. These findings suggest that the stump rotation in nerve autograft had no effect on neural regeneration and muscle reinnervation; however, it had a negative effect on functional recovery. Because GR-g was similar to PG-g rather than SR-g in functional recovery, the diameter difference between fascicles appears to have had little effect on the functional recovery. The results of this study suggest that a novel approach to ATS interpretation is needed. It is recommended that (1) ATS 2 be considered the onset of autotomy instead of ATS 1; and (2) the frequency of "ATS 2 and above" should be considered for the comparison of the autotomy rather than the mean ATS.

Customized 3D Bolus Applied to the Oral Cavity and Supraclavicular Area for Head and Neck Cancer.

BACKGROUND/AIM: In this study, a new method to create a customized three-dimensional (3D) bolus by accurately considering the anatomy of an individual patient is demonstrated. PATIENTS AND METHODS: A 3D bolus structure was created from an extended planning target volume (PTV) to reduce an inevitable skin reaction. In addition, during computed tomography simulation in patients with oral cavity cancers, a balloon was inserted into the mouth of a patient to secure space, and then the area surrounding the balloon was designed into a 3D bolus structure. RESULTS: For patients with head and neck cancers, a customized 3D bolus can reduce the unnecessary skin dose by 14.4% compared to a commercial bolus. For patients with oral cavity cancer, the PTV and tongue doses were 93.8% and 8% of the prescribed dose, respectively. CONCLUSION: The customized 3D bolus enables effective skin sparing and full coverage of the target area.

Feasibility of normal tissue dose reduction in radiotherapy using low strength magnetic field.

PURPOSE: Toxicity of mucosa is one of the major concerns of radiotherapy (RT), when a target tumor is located near a mucosal lined organ. Energy of photon RT is transferred primarily by secondary electrons. If these secondary electrons could be removed in an internal cavity of mucosal lined organ, the mucosa will be spared without compromising the target tumor dose. The purpose of this study was to present a RT dose reduction in near target inner-surface (NTIS) of internal cavity, using Lorentz force of magnetic field. MATERIALS AND METHODS: Tissue equivalent phantoms, composed with a cylinder shaped internal cavity, and adjacent a target tumor part, were developed. The phantoms were irradiated using 6 MV photon beam, with or without 0.3 T of perpendicular magnetic field. Two experimental models were developed: single beam model (SBM) to analyze central axis dose distributions and multiple beam model (MBM) to simulate a clinical case of prostate cancer with rectum. RT dose of NTIS of internal cavity and target tumor area (TTA) were measured. RESULTS: With magnetic field applied, bending effect of dose distribution was visualized. The depth dose distribution of SBM showed 28.1% dose reduction of NTIS and little difference in dose of TTA with magnetic field. In MBM, cross-sectional dose of NTIS was reduced by 33.1% with magnetic field, while TTA dose were the same, irrespective of magnetic field. CONCLUSION: RT dose of mucosal lined organ, located near treatment target, could be modulated by perpendicular magnetic field.

Clinical outcome of fiducial-less CyberKnife radiosurgery for stage I non-small cell lung cancer.

PURPOSE: To evaluate the treatment results in early stage non-small cell lung cancer patients who have undergone fiducial-less CyberKnife radiosurgery (CKRS). MATERIALS AND METHODS: From June 2011 to November 2013, 58 patients underwent CKRS at Asan Medical Center for stage I lung cancer. After excluding 14 patients, we retrospectively reviewed the records of the remaining 44 patients. All analyses were performed using SPSS ver. 21. RESULTS: The median age at diagnosis was 75 years. Most patients had inoperable primary lung cancer with a poor pulmonary function test with comorbidity or old age. The clinical stage was IA in 30 patients (68.2%), IB in 14 (31.8%). The mean tumor size was 2.6 cm (range, 1.2 to 4.8 cm), and the tumor was smaller than 2 cm in 12 patients (27.3%). The radiation dose given was 48-60 Gy in 3-4 fractions. In a median follow-up of 23.1 months, local recurrence occurred in three patients (2-year local recurrence-free survival rate, 90.4%) and distant metastasis occurred in 13 patients. All patients tolerated the radiosurgery well, only two patients developing grade 3 dyspnea. The most common complications were radiation-induced fibrosis and pneumonitis. Eight patients died due to cancer progression. CONCLUSION: The results showed that fiducial-less CKRS shows comparable local tumor control and survival rates to those of LINAC-based SABR or CKRS with a fiducial marker. Thus, fiducial-less CKRS using Xsight lung tracking system can be effectively and safely performed for patients with medically inoperable stage I non-small cell lung cancer without any risk of procedure-related complication.

Postoperative radiotherapy for gallbladder cancer.

AIM: To evaluate the results of postoperative radiotherapy (PORT) and to identify prognostic factors for gallbladder cancer (GBC). PATIENTS AND METHODS: We retrospectively analyzed 86 patients with GBC who underwent potentially curative surgical resection and PORT between November 1993 and December 2009. All patients received three-dimensional conformal radiotherapy and 61 patients (71%) had concurrent chemotherapy. Survival outcomes including locoregional control (LRC), disease-free survival (DFS) and overall survival (OS) rates were analyzed. RESULTS: The median follow-up period was 83 months for surviving patients. The 5-year OS, DFS and LRC rates were 42%, 36% and 73%, respectively. Isolated locoregional recurrence as first failure occurred in seven patients (8%). On multivariate analysis, the postoperative carbohydrate antigen 19-9 (CA 19-9) level was a significant prognostic factor for LRC, DFS and OS. CONCLUSION: Adjuvant radiotherapy might be an effective treatment in terms of LRC in GBC. Postoperative CA 19-9 might be useful as a surrogate marker for survival.