PURPOSE: This study was performed to assess frequency, timings of occurrence, and predictors of radiologic lung damage (RLD) after forward-planned intensity-modulated radiotherapy (FIMRT) for whole breast irradiation. METHODS: We retrospectively reviewed medical records of 157 breast cancer patients and each of their serial chest computed tomography (CT) taken 4, 10, 16, and 22 months after completion of breast radiotherapy (RT). FIMRT was administered to whole breast only (n=152), or whole breast and supraclavicular regions (n=5). Dosimetric parameters, such as mean lung dose and lung volume receiving more than 10 to 50 Gy (V10-V50), and clinical parameters were analyzed in relation to radiologic lung damage. RESULTS: In total, 104 patients (66.2%) developed RLD after whole breast FIMRT. Among the cases of RLD, 84.7% were detected at 4 months, and 15.3% at 10 months after completion of RT. More patients of 47 or younger were found to have RLD at 10 months after RT than patients older than the age (11.7% vs. 2.9%, p=0.01). In univariate and multivariate analyses, age >47 and V40 >7.2% were significant predictors for higher risk of RLD. CONCLUSION: RLD were not infrequently detected in follow-up CT after whole breast FIMRT. More detected cases of RLD among younger patients are believed to have developed at later points after RT than those of older patients. Age and V40 were significant predictors for RLD after whole breast intensity-modulated radiotherapy.
Breast Neoplasms ; Breast* ; Follow-Up Studies ; Humans ; Lung Injury* ; Lung* ; Medical Records ; Multivariate Analysis ; Radiotherapy ; Radiotherapy, Intensity-Modulated* ; Retrospective Studies ; Thorax

Less execution of the electron arc treatment could in large part be attributed to the lack of an adequate planning system. Unlike most linear accelerators providing the electron arc mode, no commercial planning systems for the electron arc plan are available at this time. In this work, with the expectation that an easily accessible planning system could promote electron arc therapy, a commercial planning system was commissioned and evaluated for the electron arc plan. For the electron arc plan with use of a Varian 21-EX, Pinnacle3 (ver. 7.4f), with an electron pencil beam algorithm, was commissioned in which the arc consisted of multiple static fields with a fixed beam opening. Film dosimetry and point measurements were executed for the evaluation of the computation. Beam modeling was not satisfactory with the calculation of lateral profiles. Contrary to good agreement within 1% of the calculated and measured depth profiles, the calculated lateral profiles showed underestimation compared with measurements, such that the distance-to-agreement (DTA) was 5.1 mm at a 50% dose level for 6 MeV and 6.7 mm for 12 MeV with similar results for the measured depths. Point and film measurements for the humanoid phantom revealed that the delivered dose was more than the calculation by approximately 10%. The electron arc plan, based on the pencil beam algorithm, provides qualitative information for the dose distribution. Dose verification before the treatment should be mandatory.
Electrons ; Film Dosimetry ; Particle Accelerators

Radiation treatment techniques using photon beam such as three-dimensional conformal radiation therapy (3D-CRT) as well as intensity modulated radiotherapy treatment (IMRT) demand accurate dose calculation in order to increase target coverage and spare healthy tissue. Both jaw collimator and multi-leaf collimators (MLCs) for photon beams have been used to achieve such goals. In the Pinnacle3 treatment planning system (TPS), which we are using in our clinics, a set of model parameters like jaw collimator transmission factor (JTF) and MLC transmission factor (MLCTF) are determined from the measured data because it is using a model-based photon dose algorithm. However, model parameters obtained by this auto-modeling process can be different from those by direct measurement, which can have a dosimetric effect on the dose distribution. In this paper we estimated JTF and MLCTF obtained by the auto-modeling process in the Pinnacle3 TPS. At first, we obtained JTF and MLCTF by direct measurement, which were the ratio of the output at the reference depth under the closed jaw collimator (MLCs for MLCTF) to that at the same depth with the field size 10x10 cm2 in the water phantom. And then JTF and MLCTF were also obtained by auto-modeling process. And we evaluated the dose difference through phantom and patient study in the 3D-CRT plan. For direct measurement, JTF was 0.001966 for 6 MV and 0.002971 for 10 MV, and MLCTF was 0.01657 for 6 MV and 0.01925 for 10 MV. On the other hand, for auto-modeling process, JTF was 0.001983 for 6 MV and 0.010431 for 10 MV, and MLCTF was 0.00188 for 6 MV and 0.00453 for 10 MV. JTF and MLCTF by direct measurement were very different from those by auto-modeling process and even more reasonable considering each beam quality of 6 MV and 10 MV. These different parameters affect the dose in the low-dose region. Since the wrong estimation of JTF and MLCTF can lead some dosimetric error, comparison of direct measurement and auto-modeling of JTF and MLCTF would be helpful during the beam commissioning.
Hand ; Humans ; Jaw ; Water

Purpose: This study aimed to evaluate the effects of bladder cuff method on oncological outcomes in patients who underwent radical nephroureterectomy (RNU) for upper tract urothelial carcinoma. Materials and Methods: The records of 1,095 patients treated with RNU performed at our hospital between 1994 and 2018 were retrospectively reviewed; 856 patients with no bladder tumor history were enrolled in the present study. The management of bladder cuff was divided into two categories: extravesical ligation (EL) or transvesical resection (TR). Survival was analyzed using the Kaplan-Meier method and Cox regression analyses were performed to determine which factors were associated with intravesical recurrence (IVR)–free survival (IVRFS), cancer-specific survival (CSS), and overall survival (OS). Results: The mean patient age was 64.8 years and the median follow-up was 37.7 months. Among the 865 patients, 477 (55.7%) underwent the TR and 379 (44.3%) the EL. Significantly higher IVRFS (p=0.001) and OS (p=0.013) were observed in the TR group. In multivariable analysis, IVR, CSS, and OS were independently associated with the EL. Among 379 patients treated with the EL, eight underwent remnant ureterectomy. Based on radical cystectomy–free survival, significant difference was not observed between the two groups. However, significantly higher IVRFS was observed in the TR group when the tumor was located in the renal pelvis. Conclusion Intramural complete excision of the distal ureter during RNU should be the gold standard approach compared with EL for the management of distal ureter in terms of oncological outcomes.

Purpose: To analyze and compare the results of robotic partial nephrectomy (RPN) at a single center with the previous large-scale studies in terms of perioperative and oncological outcomes. Materials and Methods: We retrospectively evaluated 1,013 cases of RPN in our center database from December 2008 to August 2018. Total 11 cases were excluded in final analysis. We evaluated perioperative outcomes as the Trifecta achievement, which is defined as no positive surgical margin (PSM), no perioperative complications greater than Clavien-Dindo classification I and a warm ischemia time of <25 minutes. In addition, we analyzed pathological and oncological outcomes; recurrence, metastasis, all-cause deaths, cancer-specific deaths, and 5-year survival rates. Results: In 1,002 cases, the Trifecta achievement was 61.1% (n=612). The postoperative complication was 18.4% (n=184) but most were grade 2 or less (14.9%, n=145). Ninety-three cases (9.28%) had benign and 907 cases (90.5%) had malignant pathologies. A local recurrence were 14 cases (1.54%) and distant metastasis were 20 cases (2.2%) during follow-up periods. Allcause death rate was 1.2% (n=11) and cancer-specific death rate was 0.2% (n=2). The median follow-up period was 39 months. A 5-year recurrence-free survival rate, cancer-specific survival rate, and overall survival rate were 95.2%, 99.7%, and 98.4%. Conclusions In summary, our data shows comparable perioperative outcomes to other largescale studies of RPN in terms of the Trifecta achievement with similar baseline characteristics. In terms of oncological outcomes, there was lower rate of PSM and similar recurrence free survival rate.

Purpose: This study aimed to evaluate the effects of bladder cuff method on oncological outcomes in patients who underwent radical nephroureterectomy (RNU) for upper tract urothelial carcinoma. Materials and Methods: The records of 1,095 patients treated with RNU performed at our hospital between 1994 and 2018 were retrospectively reviewed; 856 patients with no bladder tumor history were enrolled in the present study. The management of bladder cuff was divided into two categories: extravesical ligation (EL) or transvesical resection (TR). Survival was analyzed using the Kaplan-Meier method and Cox regression analyses were performed to determine which factors were associated with intravesical recurrence (IVR)–free survival (IVRFS), cancer-specific survival (CSS), and overall survival (OS). Results: The mean patient age was 64.8 years and the median follow-up was 37.7 months. Among the 865 patients, 477 (55.7%) underwent the TR and 379 (44.3%) the EL. Significantly higher IVRFS (p=0.001) and OS (p=0.013) were observed in the TR group. In multivariable analysis, IVR, CSS, and OS were independently associated with the EL. Among 379 patients treated with the EL, eight underwent remnant ureterectomy. Based on radical cystectomy–free survival, significant difference was not observed between the two groups. However, significantly higher IVRFS was observed in the TR group when the tumor was located in the renal pelvis. Conclusion Intramural complete excision of the distal ureter during RNU should be the gold standard approach compared with EL for the management of distal ureter in terms of oncological outcomes.

Purpose: To analyze and compare the results of robotic partial nephrectomy (RPN) at a single center with the previous large-scale studies in terms of perioperative and oncological outcomes. Materials and Methods: We retrospectively evaluated 1,013 cases of RPN in our center database from December 2008 to August 2018. Total 11 cases were excluded in final analysis. We evaluated perioperative outcomes as the Trifecta achievement, which is defined as no positive surgical margin (PSM), no perioperative complications greater than Clavien-Dindo classification I and a warm ischemia time of <25 minutes. In addition, we analyzed pathological and oncological outcomes; recurrence, metastasis, all-cause deaths, cancer-specific deaths, and 5-year survival rates. Results: In 1,002 cases, the Trifecta achievement was 61.1% (n=612). The postoperative complication was 18.4% (n=184) but most were grade 2 or less (14.9%, n=145). Ninety-three cases (9.28%) had benign and 907 cases (90.5%) had malignant pathologies. A local recurrence were 14 cases (1.54%) and distant metastasis were 20 cases (2.2%) during follow-up periods. Allcause death rate was 1.2% (n=11) and cancer-specific death rate was 0.2% (n=2). The median follow-up period was 39 months. A 5-year recurrence-free survival rate, cancer-specific survival rate, and overall survival rate were 95.2%, 99.7%, and 98.4%. Conclusions In summary, our data shows comparable perioperative outcomes to other largescale studies of RPN in terms of the Trifecta achievement with similar baseline characteristics. In terms of oncological outcomes, there was lower rate of PSM and similar recurrence free survival rate.