We published in May 10, 2022 a retrospective cohort study comparing the post-radiotherapy (post-RT) hemoglobin levels between patients with breast cancer who underwent intensity-modulated radiotherapy (IMRT) and those who underwent three-dimensional conformal radiotherapy (3D-CRT) in the Radiation Oncology Section of the Department of Radiological and Imaging Sciences of Southern Philippines Medical Center (ROS DORIS-SPMC) from October 2018 to March 2019. It came to our knowledge that the IMRT planning that was done on the patients included in our study was different from the IMRT planning that is currently being done since late 2020. Prior to late 2020, ROS DORIS-SPMC had been implementing forward-planned IMRT, wherein the weight of the multileaf collimator (MLC) segment was preselected at fixed values. In late 2020, ROS DORIS-SPMC started implementing inverse-planned IMRT, wherein the appropriate weights of the MLC segments are determined by an inverse optimization algorithm that creates a more uniform dose distribution throughout the target. Inverse-planned IMRT improves the dose homogeneity within the entire 3D-breast volume, while forward-planned IMRT mainly improves the dose distribution on the inframammary fold.1 Compared to 3D-CRT, however, forward-planned IMRT improves target homogeneity, albeit to a lesser degree than the homogeneity produced by the inverse technique.2 In the original article, we also stated that, for both IMRT and 3D-CRT, each dose fraction is given weekly within a span of 7 to 8 months. We recently confirmed that, among patients with breast cancer, each dose fraction of IMRT or 3D-CRT is given daily within a span of 33 days—28 days for conventional dose and 5 days for boost dose. In this corrigendum, we specify that the IMRT protocol used among the patients in our study was forward-planned IMRT, with all dose fractions given daily for 33 consecutive workdays, excluding weekends and holidays. We also describe here the original statements that we changed or removed because they have become irrelevant in light of the corrections. The table below shows the list of corrections.
Radiotherapy, Intensity-Modulated ; Radiotherapy, Conformal

KylinRay-IMRT is the advanced radiotherapy treatment planning module of accurate radiotherapy system (KylinRay) aiming to provide accurate and efficient plan design platform. In this paper the system design, main functions and key technologies of KylinRay-IMRT were introduced. KylinRay-IMRT supports three dimensional conformal radiotherapy (3D-CRT), intensity modulated radiotherapy (IMRT) and many other types of treatment plan design with function modules including patient data management, image registration and fusion, image contouring, image three dimensional reconstruction and visualization, three dimensional conformal radiotherapy planning, intensity modulated radiotherapy planning, plan evaluation and comparison, and report print. KylinRay-IMRT has been tested by the national standard YY/T 0889-2013, the results showed that the performance of KylinRay-IMRT can fully meet the standard requirements.
Humans ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted ; Radiotherapy, Conformal ; Radiotherapy, Intensity-Modulated ; Tomography, X-Ray Computed

PURPOSE: Radiotherapy of the neck is known to cause carotid artery stenosis. We compared the carotid artery dose received between volumetric modulated arc therapy (VMAT) and conventional fixed-field intensity-modulated radiotherapy (IMRT) plans in patients with early glottic cancer. MATERIALS AND METHODS: Twenty-one early glottic cancer patients who previously underwent definitive radiotherapy were selected for this study. For each patient, double arc VMAT, 8-field IMRT, 3-dimensional conformal radiotherapy (3DCRT), and lateral parallel-opposed photon field radiotherapy (LPRT) plans were created. The 3DCRT plan was generated using lateral parallel-opposed photon fields plus an anterior photon field. VMAT and IMRT treatment plan optimization was performed under standardized conditions to obtain adequate target volume coverage and spare the carotid artery. Dose-volume specifications for the VMAT, IMRT, 3DCRT, and LPRT plans were calculated with radiotherapy planning system. Monitor units (MUs) and delivery time were measured to evaluate treatment efficiency. RESULTS: Target volume coverage and homogeneity results were comparable between VMAT and IMRT; however, VMAT was superior to IMRT for carotid artery dose sparing. The mean dose to the carotid arteries in double arc VMAT was reduced by 6.8% compared to fixed-field IMRT (p < 0.001). The MUs for VMAT and IMRT were not significantly different (p = 0.089). VMAT allowed an approximately two-fold reduction in treatment delivery time in comparison to IMRT (3 to 5 minutes vs. 5 to 10 minutes). CONCLUSION: VMAT resulted in a lower carotid artery dose compared to conventional fixed-field IMRT, and maintained good target coverage in patients with early glottic cancer.
Animals ; Carotid Arteries ; Carotid Stenosis ; Glottis ; Humans ; Mice ; Neck ; Radiotherapy ; Radiotherapy, Conformal ; Radiotherapy, Intensity-Modulated*

PURPOSE: The objective of this study was to compare dosimetric characteristics of three-dimensional conformal radiotherapy (3D-CRT) and two types of intensity-modulated radiotherapy (IMRT) which are step-and-shoot intensity modulated radiotherapy (s-IMRT) and modulated arc therapy (mARC) for thoracic esophageal cancer and analyze whether IMRT could reduce organ-at-risk (OAR) dose. MATERIALS AND METHODS: We performed 3D-CRT, s-IMRT, and mARC planning for ten patients with thoracic esophageal cancer. The dose-volume histogram for each plan was extracted and the mean dose and clinically significant parameters were analyzed. RESULTS: Analysis of target coverage showed that the conformity index (CI) and conformation number (CN) in mARC were superior to the other two plans (CI, p = 0.050; CN, p = 0.042). For the comparison of OAR, lung V5 was lowest in s-IMRT, followed by 3D-CRT, and mARC (p = 0.033). s-IMRT and mARC had lower values than 3D-CRT for heart V30 (p = 0.039), V40 (p = 0.040), and V50 (p = 0.032). CONCLUSION: Effective conservation of the lung and heart in thoracic esophageal cancer could be expected when using s-IMRT. The mARC was lower in lung V10, V20, and V30 than in 3D-CRT, but could not be proven superior in lung V5. In conclusion, low-dose exposure to the lung and heart were expected to be lower in s-IMRT, reducing complications such as radiation pneumonitis or heart-related toxicities.
Esophageal Neoplasms ; Heart ; Humans ; Lung ; Radiation Pneumonitis ; Radiotherapy ; Radiotherapy, Conformal ; Radiotherapy, Intensity-Modulated

PURPOSE: The purpose of this study was to investigate the dosimetric benefits and treatment efficiency of carotid-sparing TomoHelical 3-dimensional conformal radiotherapy (TH-3DCRT) for early glottic cancer. MATERIALS AND METHODS: Ten early-stage (T1N0M0) glottic squamous cell carcinoma patients were simulated, based on computed tomography scans. Two-field 3DCRT (2F-3DCRT), 3-field intensity-modulated radiation therapy (3F-IMRT), TomoHelical-IMRT (TH-IMRT), and TH-3DCRT plans were generated with a 67.5-Gy total prescription dose to the planning target volume (PTV) for each patient. In order to evaluate the plan quality, dosimetric characteristics were compared in terms of conformity index (CI) and homogeneity index (HI) for PTV, dose to the carotid arteries, and maximum dose to the spinal cord. Treatment planning and delivery times were compared to evaluate treatment efficiency. RESULTS: The median CI was substantially better for the 3F-IMRT (0.65), TH-IMRT (0.64), and TH-3DCRT (0.63) plans, compared to the 2F-3DCRT plan (0.32). PTV HI was slightly better for TH-3DCRT and TH-IMRT (1.05) compared to 2F-3DCRT (1.06) and 3F-IMRT (1.09). TH-3DCRT, 3F-IMRT, and TH-IMRT showed an excellent carotid sparing capability compared to 2F-3DCRT (p < 0.05). For all plans, the maximum dose to the spinal cord was < 45 Gy. The median treatment planning times for 2F-3DCRT (5.85 minutes) and TH-3DCRT (7.10 minutes) were much lower than those for 3F-IMRT (45.48 minutes) and TH-IMRT (35.30 minutes). The delivery times for 2F-3DCRT (2.06 minutes) and 3F-IMRT (2.48 minutes) were slightly lower than those for TH-IMRT (2.90 minutes) and TH-3DCRT (2.86 minutes). CONCLUSION: TH-3DCRT showed excellent carotid-sparing capability, while offering high efficiency and maintaining good PTV coverage.
Carcinoma, Squamous Cell ; Carotid Arteries ; Humans ; Prescriptions ; Radiotherapy, Conformal* ; Radiotherapy, Intensity-Modulated ; Spinal Cord

BACKGROUNDThe role of internal mammary nodes (IMN) irradiation for breast cancer patients after mastectomy remains controversial. This study aimed to compare different techniques for radiation of the chest wall (CW) and IMN post-mastectomy for left-breast cancer patients in terms of dose homogeneity within planning target volume (PTV) and dose to critical structures.

METHODSThirty patients underwent CT simulation, while CW, IMN, left lung, heart and contralateral breast were contoured. Three three-dimensional conformal radiotherapy (3D-CRT) techniques, namely, standard tangents, partially wide tangents (PWT), and modified PWT techniques plus intensity modulated radiotherapy (IMRT) technique have been used to radiate CW and IMN. In addition to the target coverage and dose homogeneity, we also evaluated the dose to the critical structures including heart, left lung and contralateral breast.

RESULTSAll three 3D-CRT techniques provided satisfactory coverage regarding total PTV. The PWT and the modified PWT gave better coverage of IMN PTV with V(47.5) of (96.83 ± 4.56)% and (95.19 ± 3.90)% compared to standard tangents ((88.16 ± 7.77)%), P < 0.05. The standard tangents also contributed the biggest IMN V(D105%), V(D110%), V(D115%) and V(D120%). The lowest mean dose of the heart was achieved by the modified PWT ((8.47 ± 2.30) Gy), compared with PWT ((11.97 ± 3.54) Gy) and standard tangents ((11.18 ± 2.53) Gy). The mean dose of lung and contralateral breast with the modified PWT was significantly lower than those with PWT. Comparing IMRT with the modified PWT, both techniques provided satisfactory coverage. The conformity indexes (CI) with IMRT (CI1: 0.71 ± 0.02; CI2: 0.64 ± 0.02) were better than those with the modified PWT (CI1: 0.50 ± 0.02; CI2: 0.45 ± 0.02). The mean dose, V(5), V(10) and V(5-10) of heart and left lung with the modified PWT were significantly lower than those with the IMRT. The mean dose and V(D2%) of contralateral breast with the modified PWT were not significantly different from the IMRT (P = 0.868 and P = 0.212).

CONCLUSIONSNo single technique provides both the best CW and IMN coverage with minimum lung and heart dose. The modified PWT technique can be used as a clinical tool for the treatment of the left-sided post-mastectomy breast cancer patients to provide homogeneous target coverage while maintaining low doses to normal tissue.

Breast Neoplasms ; radiotherapy ; surgery ; Combined Modality Therapy ; Female ; Humans ; Mastectomy ; Radiotherapy Dosage ; Radiotherapy, Conformal ; methods ; Radiotherapy, Intensity-Modulated ; methods

Brachytherapy is an essential part of the radiotherapy for uterine cervical cancer. Since 1979, high dose rate (HDR) brachytherapy has been used for the treatment of uterine cervical cancer in Korea; the number of institutions employing HDR has been increasing. At 40 radiation oncology departments out of 53 in Korea, HDR brachytherapy was practiced in 2004. Approximately in 1,000 of patients, brachytherapy was done annually and among these, HDR proportions were 75-80%. In Korea, treatment results for HDR are comparable with the low dose rate (LDR) system series and appear to be a safe and effective alternative to LDR for the treatment of cervical carcinoma. The studies from the major centers report the five-year survival rate of cervical cancer as, 78-86% for Stage I, 68-85% for stage II, and 38-56% for Stage III. In conclusion, HDR intracavitary radiotherapy is increasingly practiced in Korea and an effective treatment modality for cervical cancer. To determine the optimum radiation dose and fractionation schedule, a nation-wide prospective study is necessary in Korea. Recently a three-dimensional conformal radiotherapy (3DCRT) or an intensity-modulated radiotherapy (IMRT), which allow for a high degree of conformity to the target volume have been used for the uterine cervical cancer. Several studies have reported the superiority of IMRT, over the conventional technique, in reducing the small bowel dose. The author will introduce the small bowel displacement system (SBDS)-assisted IMRT for cervical cancer patients. Positional changes of the uterus during radiotherapy, which can degrade the accuracy of 3DCRT and IMRT, will be discussed.
Appointments and Schedules ; Brachytherapy ; Humans ; Korea* ; Radiation Oncology ; Radiotherapy ; Radiotherapy, Conformal ; Radiotherapy, Intensity-Modulated ; Survival Rate ; Uterine Cervical Neoplasms* ; Uterus

PURPOSE: We aimed to analyze the treatment outcome and long-term toxicity of 70 Gy hypofractionated intensity-modulated radiotherapy (IMRT) for localized prostate cancer using a customized rectal balloon. MATERIALS AND METHODS: We reviewed medical records of 86 prostate cancer patients who received curative radiotherapy between January 2004 and December 2011 at our institution. Patients were designated as low (12.8%), intermediate (20.9%), or high risk (66.3%). Thirty patients received a total dose of 70 Gy in 28 fractions over 5 weeks via IMRT (the Hypo-IMRT group); 56 received 70.2 Gy in 39 fractions over 7 weeks via 3-dimensional conformal radiotherapy (the CF-3DRT group, which served as a reference for comparison). A customized rectal balloon was placed in Hypo-IMRT group throughout the entire radiotherapy course. Androgen deprivation therapy was administered to 47 patients (Hypo-IMRT group, 17; CF-3DRT group, 30). Late genitourinary (GU) and gastrointestinal (GI) toxicity were evaluated according to the Radiation Therapy Oncology Group criteria. RESULTS: The median follow-up period was 74.4 months (range, 18.8 to 125.9 months). The 5-year actuarial biochemical relapse-free survival rates for low-, intermediate-, and high-risk patients were 100%, 100%, and 88.5%, respectively, for the Hypo-IMRT group and 80%, 77.8%, and 63.6%, respectively, for the CF-3DRT group (p < 0.046). No patient presented with acute or late GU toxicity > or =grade 3. Late grade 3 GI toxicity occurred in 2 patients (3.6%) in the CF-3DRT group and 1 patient (3.3%) in the Hypo-IMRT group. CONCLUSION: Hypo-IMRT with a customized rectal balloon resulted in excellent biochemical control rates with minimal toxicity in localized prostate cancer patients.
Follow-Up Studies ; Humans ; Medical Records ; Prostatic Neoplasms* ; Radiotherapy ; Radiotherapy, Conformal ; Radiotherapy, Intensity-Modulated* ; Survival Rate ; Treatment Outcome*

PURPOSE: Local recurrence is the most common cause of failure in retroperitoneal soft tissue sarcoma patients after surgical resection. Postoperative radiotherapy (PORT) is infrequently used due to its high complication risk. We investigated the efficacy of PORT using modern techniques in patients with retroperitoneal soft tissue sarcoma. MATERIALS AND METHODS: Eighty patients, who underwent surgical resection for non-metastatic primary retroperitoneal soft tissue sarcoma at the Yonsei Cancer Center between 1994 and 2015, were retrospectively reviewed. Thirty-eight (47.5%) patients received PORT: three-dimensional conformal radiotherapy in 29 and intensity-modulated radiotherapy in nine patients. Local failure-free survival (LFFS), overall survival (OS), and RT-related toxicities were investigated. RESULTS: Median follow-up was 37.1 months (range, 5.8–207.9). Treatment failure occurred in 47 (58.8%) patients including local recurrence in 33 (41.3%), distant metastasis in eight (10%), and both occurred in six (7.5%) patients. The 2-year and 5-year LFFS rates were 63.9% and 47.9%, respectively. The 2-year and 5-year OS rates were 87.5% and 71.1%. The 5-year LFFS rate was significantly higher in PORT group than in no-PORT group (74.2% vs. 24.3%, p < 0.001). In multivariate analysis, PORT was the only independent prognostic factor for LFFS. However, there was no significant correlation between RT dose and LFFS. OS showed no significant difference between the two groups. Grade ≤2 acute toxicities were observed in 63% of patients, but no acute toxicity ≥grade 3 was observed. CONCLUSION: PORT using modern technique markedly reduced local recurrence in retroperitoneal sarcoma patients, with low toxicity. The optimal RT technique, in terms of RT dose and target volume, should be further investigated.
Follow-Up Studies ; Humans ; Multivariate Analysis ; Neoplasm Metastasis ; Radiotherapy* ; Radiotherapy, Conformal ; Radiotherapy, Intensity-Modulated ; Recurrence ; Retrospective Studies ; Sarcoma* ; Treatment Failure

PURPOSE: To evaluate the results of hypofractionated radiotherapy (HFX) for early glottic cancer. MATERIALS AND METHODS: Eighty-five patients with cT1-2N0M0 squamous cell carcinoma of the glottis who had undergone HFX, performed using intensity-modulated radiotherapy (IMRT, n = 66) and three-dimensional conformal radiotherapy (3D CRT, n = 19) were analyzed. For all patients, radiotherapy was administered at 60.75 Gy in 27 fractions. Forty-three patients received a simultaneous integrated boost (SIB) of 2.3–2.5 Gy per tumor fraction. RESULTS: The median follow-up duration was 29.9 months (range, 5.5 to 76.5 months). All patients achieved complete remission at a median of 50 days after the end of radiotherapy (range, 14 to 206 days). The 5-year rates for locoregional recurrence-free survival was 88.1%, and the 5-year overall survival rate was 86.2%. T2 stage was a prognostic factor for locoregional recurrence-free survival after radiotherapy (p = 0.002). SIB for the tumor did not affect disease control and survival (p = 0.191 and p = 0.387, respectively). No patients experienced acute or chronic toxicities of ≥grade 3. IMRT significantly decreased the dose administered to the carotid artery as opposed to 3D CRT (V₃₅, p < 0.001; V₅₀, p < 0.001). CONCLUSIONS: Patients treated with HFX achieved acceptable locoregional disease control rates and overall survival rates compared with previous HFX studies. A fraction size of 2.25 Gy provided good disease control regardless of SIB administration.
Carcinoma, Squamous Cell ; Carotid Arteries ; Follow-Up Studies ; Glottis ; Humans ; Radiotherapy ; Radiotherapy, Conformal ; Radiotherapy, Intensity-Modulated ; Retrospective Studies ; Survival Rate