6.Intra-Fractional Dose Evaluation for Patients with Breast Cancer Using Synthetic Computed Tomography
Sohyun AHN ; So Eun CHOI ; Jeong-Heon KIM ; Kwangwoo PARK ; Hai-Jeon YOON
Progress in Medical Physics 2024;35(4):145-154
Purpose:
This study investigated the use of synthetic computed tomography (CT) images derived from cone beam CT (CBCT) scans to analyze dose changes in breast cancer patients undergoing treatment and to evaluate the optimal timing for implementing adaptive radiotherapy.
Methods:
A retrospective analysis was conducted on five breast cancer patients treated with tomotherapy-based volumetric-modulated arc therapy at Yongin Severance Hospital. Each patient received 15 fractions, with doses of 320 centigray (cGy) to the high-dose planning target volume (PTV) and 267 cGy to the low-dose PTV. Planning CT images were acquired using the Aquilion scanner, andCBCT images were captured with the VersaHD linear accelerator’s on-board imager. These imageswere registered in RayStation using a hybrid deformable image registration method to generate synthetic CT images. Dose distributions were reanalyzed using the synthetic CT images, and dose-volume histogram parameters, including the dose to 95% of the volume (D95 ) and mean dose (Dmean ) for the PTV, as well as D95 , Dmean , the percentage of the volume receiving at least 5 Gy (V5 ) and 10 Gy (V10 )for organs-at-risk (OARs), were extracted using MATLAB to assess dose changes during treatment.
Results:
For the original plans, the mean D95 for PTV high across all patients was 287.13±31.32cGy, while for PTV low, it was 245.53±6.21 cGy. In contrast, the adaptive plans yielded a mean D95of 298.17±12.37 cGy for PTV High and 247.25±4.23 cGy for PTV low. The ART Plan may lead to increased dose exposure in certain structures, such as the spinal cord, while providing targeted improvements in reducing radiation exposure in specific OARs (e.g., contralateral breast and esophagus).
Conclusions
Synthetic CT images generated from CBCT scans provide a fast and efficient means of quantifying dose changes, supporting precise patient care through interfractional evaluation.Future studies will aim to apply this method to other organs and larger patient cohorts.
7.Intra-Fractional Dose Evaluation for Patients with Breast Cancer Using Synthetic Computed Tomography
Sohyun AHN ; So Eun CHOI ; Jeong-Heon KIM ; Kwangwoo PARK ; Hai-Jeon YOON
Progress in Medical Physics 2024;35(4):145-154
Purpose:
This study investigated the use of synthetic computed tomography (CT) images derived from cone beam CT (CBCT) scans to analyze dose changes in breast cancer patients undergoing treatment and to evaluate the optimal timing for implementing adaptive radiotherapy.
Methods:
A retrospective analysis was conducted on five breast cancer patients treated with tomotherapy-based volumetric-modulated arc therapy at Yongin Severance Hospital. Each patient received 15 fractions, with doses of 320 centigray (cGy) to the high-dose planning target volume (PTV) and 267 cGy to the low-dose PTV. Planning CT images were acquired using the Aquilion scanner, andCBCT images were captured with the VersaHD linear accelerator’s on-board imager. These imageswere registered in RayStation using a hybrid deformable image registration method to generate synthetic CT images. Dose distributions were reanalyzed using the synthetic CT images, and dose-volume histogram parameters, including the dose to 95% of the volume (D95 ) and mean dose (Dmean ) for the PTV, as well as D95 , Dmean , the percentage of the volume receiving at least 5 Gy (V5 ) and 10 Gy (V10 )for organs-at-risk (OARs), were extracted using MATLAB to assess dose changes during treatment.
Results:
For the original plans, the mean D95 for PTV high across all patients was 287.13±31.32cGy, while for PTV low, it was 245.53±6.21 cGy. In contrast, the adaptive plans yielded a mean D95of 298.17±12.37 cGy for PTV High and 247.25±4.23 cGy for PTV low. The ART Plan may lead to increased dose exposure in certain structures, such as the spinal cord, while providing targeted improvements in reducing radiation exposure in specific OARs (e.g., contralateral breast and esophagus).
Conclusions
Synthetic CT images generated from CBCT scans provide a fast and efficient means of quantifying dose changes, supporting precise patient care through interfractional evaluation.Future studies will aim to apply this method to other organs and larger patient cohorts.
8.Capsular Contracture After Postmastectomy Radiation in Implant-Based Breast Reconstruction:Effect of Implant Pocket and Two-Stage Surgery
Sohyun MOON ; Kyunghyun MIN ; Tae Ho KIM ; Jung Hwan UM ; Yoonwon KOOK ; Seung Ho BAEK ; In Sik YUN ; Tai Suk ROH ; Soong June BAE ; Joon JEONG ; Sung Gwe AHN ; Young Seok KIM
Journal of Breast Cancer 2024;27(6):395-406
Capsular contracture (CC) is a concerning issue for individuals undergoing postmastectomy radiation therapy (PMRT) with implant-based breast reconstruction. This study investigated whether the extent of CC and implant migration differs based on implant placement and the reconstruction stage. Insertion plane and stage of breast implants were investigated, and the presence and severe cases of CC and implant migration were analyzed. Among 195 participants, 83 were in the pre-pectoral group, and 112 were in the sub-pectoral group. Two-staged surgery was performed on 116 patients, while 79 underwent direct-to-implant (DTI).Notably, The occurrence of CC (prepectoral, 17 [20.48%] and subpectoral, 42 [37.50%];p = 0.011), CC severity (prepectoral, 4 [4.82%] and subpectoral, 17 [15.17%]; p = 0.021), and implant upward migration (prepectoral, 15 [18.07%] and subpectoral, 38 [33.92%]; p = 0.014) significantly varied between the two groups. The incidence of CC was more common in the DTI group (odds ratio [OR], 2.283; 95% confidence interval [CI], 1.164–4.478). Furthermore, subpectoral placement was an independent risk factor for occurrence (OR, 2.989; 95% CI, 1.476–6.054) and severity of CC (OR, 38.552; 95% CI, 1.855–801.186) and upward implant migration (OR, 2.531; 95% CI, 1.263–5.071). Our findings suggest that pre-pectoral reconstruction and the two-stage operation benefit patients who may undergo PMRT. These approaches can help reduce the incidence of CC and abnormal implant migration following radiation, leading to improved aesthetic outcomes and greater patient satisfaction.
9.Korean Thyroid Association Guidelines on the Management of Differentiated Thyroid Cancers; Overview and Summary 2024
Young Joo PARK ; Eun Kyung LEE ; Young Shin SONG ; Bon Seok KOO ; Hyungju KWON ; Keunyoung KIM ; Mijin KIM ; Bo Hyun KIM ; Won Gu KIM ; Won Bae KIM ; Won Woong KIM ; Jung-Han KIM ; Hee Kyung KIM ; Hee Young NA ; Shin Je MOON ; Jung-Eun MOON ; Sohyun PARK ; Jun-Ook PARK ; Ji-In BANG ; Kyorim BACK ; Youngduk SEO ; Dong Yeob SHIN ; Su-Jin SHIN ; Hwa Young AHN ; So Won OH ; Seung Hoon WOO ; Ho-Ryun WON ; Chang Hwan RYU ; Jee Hee YOON ; Ka Hee YI ; Min Kyoung LEE ; Sang-Woo LEE ; Seung Eun LEE ; Sihoon LEE ; Young Ah LEE ; Joon-Hyop LEE ; Ji Ye LEE ; Jieun LEE ; Cho Rok LEE ; Dong-Jun LIM ; Jae-Yol LIM ; Yun Kyung JEON ; Kyong Yeun JUNG ; Ari CHONG ; Yun Jae CHUNG ; Chan Kwon JUNG ; Kwanhoon JO ; Yoon Young CHO ; A Ram HONG ; Chae Moon HONG ; Ho-Cheol KANG ; Sun Wook KIM ; Woong Youn CHUNG ; Do Joon PARK ; Dong Gyu NA ;
International Journal of Thyroidology 2024;17(1):1-20
Differentiated thyroid cancer demonstrates a wide range of clinical presentations, from very indolent cases to those with an aggressive prognosis. Therefore, diagnosing and treating each cancer appropriately based on its risk status is important. The Korean Thyroid Association (KTA) has provided and amended the clinical guidelines for thyroid cancer management since 2007. The main changes in this revised 2024 guideline include 1) individualization of surgical extent according to pathological tests and clinical findings, 2) application of active surveillance in low-risk papillary thyroid microcarcinoma, 3) indications for minimally invasive surgery, 4) adoption of World Health Organization pathological diagnostic criteria and definition of terminology in Korean, 5) update on literature evidence of recurrence risk for initial risk stratification, 6) addition of the role of molecular testing, 7) addition of definition of initial risk stratification and targeting thyroid stimulating hormone (TSH) concentrations according to ongoing risk stratification (ORS), 8) addition of treatment of perioperative hypoparathyroidism, 9) update on systemic chemotherapy, and 10) addition of treatment for pediatric patients with thyroid cancer.
10.Capsular Contracture After Postmastectomy Radiation in Implant-Based Breast Reconstruction:Effect of Implant Pocket and Two-Stage Surgery
Sohyun MOON ; Kyunghyun MIN ; Tae Ho KIM ; Jung Hwan UM ; Yoonwon KOOK ; Seung Ho BAEK ; In Sik YUN ; Tai Suk ROH ; Soong June BAE ; Joon JEONG ; Sung Gwe AHN ; Young Seok KIM
Journal of Breast Cancer 2024;27(6):395-406
Capsular contracture (CC) is a concerning issue for individuals undergoing postmastectomy radiation therapy (PMRT) with implant-based breast reconstruction. This study investigated whether the extent of CC and implant migration differs based on implant placement and the reconstruction stage. Insertion plane and stage of breast implants were investigated, and the presence and severe cases of CC and implant migration were analyzed. Among 195 participants, 83 were in the pre-pectoral group, and 112 were in the sub-pectoral group. Two-staged surgery was performed on 116 patients, while 79 underwent direct-to-implant (DTI).Notably, The occurrence of CC (prepectoral, 17 [20.48%] and subpectoral, 42 [37.50%];p = 0.011), CC severity (prepectoral, 4 [4.82%] and subpectoral, 17 [15.17%]; p = 0.021), and implant upward migration (prepectoral, 15 [18.07%] and subpectoral, 38 [33.92%]; p = 0.014) significantly varied between the two groups. The incidence of CC was more common in the DTI group (odds ratio [OR], 2.283; 95% confidence interval [CI], 1.164–4.478). Furthermore, subpectoral placement was an independent risk factor for occurrence (OR, 2.989; 95% CI, 1.476–6.054) and severity of CC (OR, 38.552; 95% CI, 1.855–801.186) and upward implant migration (OR, 2.531; 95% CI, 1.263–5.071). Our findings suggest that pre-pectoral reconstruction and the two-stage operation benefit patients who may undergo PMRT. These approaches can help reduce the incidence of CC and abnormal implant migration following radiation, leading to improved aesthetic outcomes and greater patient satisfaction.

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