Recent trends in radiotherapy use for major cancers in Korea.

BACKGROUND: Although the trend in radiotherapy in all cancer patients has been studied, changes in radiotherapy modalities for specific cancer types have not been reported. This study aimed to analyze radiotherapy patterns for major cancers in Korea in recent years. MATERIALS AND METHODS: We collected data from claims and reimbursement records of the Health and Insurance Review and Assessment Service from 2017 to 2020, according to initial diagnostic codes. The radiotherapy modalities for major cancers, such as lung, stomach, colorectal, breast and liver cancer, were analyzed. The radiotherapy modalities consisted of two-dimensional radiotherapy, three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, proton radiotherapy and stereotactic body radiotherapy. RESULTS: Overall, from 2017 to 2020, the use of two-dimensional radiotherapy and three-dimensional conformal radiotherapy decreased, and intensity-modulated radiotherapy increased. In 2017, three-dimensional conformal radiotherapy accounted for approximately half of the radiotherapy in patients for lung and colorectal cancer, which was replaced by intensity-modulated radiotherapy in 2020. In 2020, stereotactic body radiotherapy also accounted for a large proportion of radiotherapy used in liver cancer cases. Intensity-modulated radiotherapy was most used, followed by three-dimensional conformal radiotherapy and two-dimensional radiotherapy for breast cancer in 2020. Among major cancers, radiotherapy utilization for breast cancer is the highest. Compared with other cancers, the number of patients receiving radiotherapy for stomach cancer was low. CONCLUSION: The number of patients receiving radiotherapy for major cancers has increased. The use of advanced forms of radiotherapy, such as intensity-modulated radiotherapy, is rapidly increasing for major cancers. The rate of radiotherapy utilization was higher in major cancer patients than in all cancer patients.

Comparison of radiotherapy infrastructure between Korea and Japan.

BACKGROUND: Patterns of cancer incidence and radiotherapy use are similar in Korea and Japan, with differences in radiotherapy infrastructure. METHODS: The authors surveyed the megavoltage machines in 91 radiotherapy centers in Korea and published data in Japan. The number of megavoltage machines per center was used as an indicator of the fragmentation of radiotherapy services using four as the threshold, and the number of megavoltage machines per million people was compared. The practice pattern of intensity-modulated radiation therapy was analyzed. RESULTS: There were 91 centers in Korea and 825 in Japan. The number of megavoltage machines per center was 1.3 in Japan and 2.3 in Korea. Radiotherapy infrastructure showed fragmentation in Korea and hyperfragmentation in Japan. In Japan, 75% of radiotherapy centers operated with one megavoltage machine, whereas in Korea, 47% megavoltage machines per center was 3.2 in Seoul, while that in the non-capital area was 1.8, constituting a mixed pattern of centralization and fragmentation. In Japan, megavoltage machines per center in Tokyo, Kanagawa and Osaka, was 1.5, 1.3 and 1.2, respectively, indicating no concentration in the metropolis. The number of megavoltage machines per million in Korea was 4.0, whereas that in Seoul was 8.7, constituting capital concentration. In Japan, the number of megavoltage machines per million was 8.7, whereas in Tokyo, Kanagawa and Osaka, it was is 9.3, 6.3 and 9.0, showing uniform distribution. intensity-modulated radiation therapy utilization is increasing, accounting for 15% and 23% of radiotherapy patients in Japan and Korea, respectively. CONCLUSIONS: The fragmentation of radiotherapy services in Korea and Japan might affect radiotherapy quality.

Frequency of pathogenic germline mutation in CHEK2, PALB2, MRE11, and RAD50 in patients at high risk for hereditary breast cancer.

PURPOSE: This study was performed to evaluate the frequency of mutations in CHEK2, PALB2, MRE11, and RAD50 among Korean patients at high risk for hereditary breast cancer. METHODS: A total of 235 Korean patients with hereditary breast cancer who tested negative for BRCA1/2 mutation were enrolled to this study. Entire coding regions of CHEK2, PALB2, MRE11, and RAD50 were analyzed using massively parallel sequencing (MPS). Sequence variants detected by MPS were confirmed by Sanger sequencing. RESULTS: Six patients (2.5 %) were found to have pathogenic variants in CHEK2 (n = 1), PALB2 (n = 2), MRE11 (n = 1), and RAD50 (n = 2). Among the pathogenic variants, PALB2 c.2257C>T was previously reported in other studies, while CHEK2 c.1245dupC, PALB2 c.1048C>T, MRE11 c.1773_1774delAA, RAD50 c.1276C>T, and RAD50 c.3811_3813delGAA were newly identified in this study. A total of 15 missense variants were found in the four genes among 26 patients; 7 patients had a variant in CHEK2, 11 in PALB2, 2 in MRE11, and 6 in RAD50. When in silico analyses were performed to the 15 missense variants, six variants (CHEK2 c.686A>G, PALB2 c.1492G>T, PALB2 c.3054G>C, MRE11 c.140C>T, RAD50 c.1456C>T, and RAD50 c.3790C>T) were predicted to be deleterious. CONCLUSIONS: Pathogenic variants in CHEK2, PALB2, MRE11, and RAD50 were detected in a small proportion of Korean patients with features of hereditary breast cancer.

Recurrence outcomes after omission of postoperative radiotherapy following breast-conserving surgery for ductal carcinoma in situ of the breast: a multicenter, retrospective study in Korea (KROG 16-02).

PURPOSE: To evaluate the loco-regional recurrence (LRR) rate after breast-conserving surgery without postoperative radiotherapy (RT) for ductal carcinoma in situ (DCIS) of the breast. METHODS: Between 2000 and 2010, 311 DCIS patients from 9 institutions were analyzed retrospectively. The median age was 47 (range, 20-82). The median tumor size was 7 mm (range, 0.01-76). Margin width was <1 cm in 85 patients (27.3%), and nuclear grade was high in 37 patients (11.9%). Two hundred and three patients (65.3%) received tamoxifen. RESULTS: With a median follow-up of 74 months (range, 5-189), there were 11 local recurrences (invasive carcinoma in 6 and DCIS in 5) and 1 regional recurrence. The 7-year LRR rate was 3.8%. On univariate analysis, age and margin width were significant risk factors influencing LRR (p = 0.017 and 0.014, respectively). When age and margin width were combined among 211 patients whose margin width were available, the 7-year LRR rates were as follows (p < 0.001): (1) 0% in patients with age >50 years and any margin width status (n = 64), (2) 1.2% in age ≤50 years and margin width ≥1 cm (n = 93), (3) 13.1% in age ≤50 years and margin width <1 cm (n = 54). CONCLUSIONS: The LRR rate was very low in selected DCIS patients treated with breast-conserving surgery without postoperative RT. However, adjuvant RT should be considered for those with age ≤50 years and margin width <1 cm.

Parametrial Involvement on Magnetic Resonance Imaging Has No Effect on the Survival of Early-Stage Cervical Cancer Patients.

OBJECTIVES: Parametrial involvement (PMI) in patients with cervical cancer is known to be an unfavourable prognostic factor. The purpose of this study was to investigate the prognostic significance of PMI on magnetic resonance imaging (MRI) in patients with early-stage cervical cancer. METHODS: Three hundred three patients with stage IB or IIA cervical cancer treated by adjuvant radiotherapy or concurrent chemoradiotherapy following primary surgery from 2001 to 2011 were enrolled in this study. We reviewed preoperative MRI and pathologic findings and compared recurrence and survival of group defined according to PMI status. RESULTS: There were 73 patients (24.1%) with PMI based on MRI and 52 patients (17.2%) with PMI based on surgical pathology. The accuracy of MRI for detecting PMI was 77.2% (sensitivity, 53.8%; specificity, 82.1%). In all patients, pathology-based evidence of PMI had a negative effect on both 5-year disease-free survival (73.2% vs 85.3%, P = 0.048) and 5-year overall survival (76.6% vs 91.4%, P = 0.009), but PMI on MRI did not have a significant effect on survival. In subgroups defined according to PMI status on MRI and surgical pathology, subgroups with pathology-based evidence of PMI showed a trend of a lower survival rate, regardless of PMI on MRI, but without statistical significance. CONCLUSIONS: Unlike pathologic results, PMI on MRI was not associated with recurrence or survival in patients with early-stage cervical cancer.

Patient-reported symptoms of radiation dermatitis during breast cancer radiotherapy: a pilot study.

PURPOSE: To find out which symptoms most frequently and severely affect breast cancer patients during radiotherapy and how patients manage the symptoms and unmet needs. METHODS: A cross-sectional survey was conducted with 111 patients who receive radiotherapy for breast cancer from January to April 2015 at Samsung Medical Center in Seoul, South Korea. Participants were asked about symptoms and discomfort due to radiotherapy, management methods for radiation dermatitis, unmet needs for radiation dermatitis care, and clinical and socio-demographic information. RESULTS: Of total, 108 out of 111 patients (97.3%) reported symptoms related to radiation dermatitis. Hyperpigmentation was the most commonly reported uncomfortable symptom followed by erythema. On average, patients reported 8.6 radiotherapy-induced skin problems (range, 0-11). Of total, 59 (53.2%) patients stated that they wanted care for radiation dermatitis, and 80.0, 59.4, and 51% of patients searched for information, used products, and visited the hospital to manage radiotherapy-related skin problems. Patients who experienced dryness, burning feelings, irritation, roughness, and hyperpigmentation were 11.73, 7.02, 5.10, 4.27, and 2.80 times more likely to have management needs than patients without those symptoms, respectively, adjusting age, current cycle of radiation therapy, chemotherapy, and type of surgery. CONCLUSIONS: Most of the breast cancer patients experience multiple symptoms associated with radiation dermatitis. Hyperpigmentation was the most common and uncomfortable symptom followed by erythema. Majority of patients wanted management for radiation dermatitis and patients who experienced dryness, burning feelings, irritation, roughness, and hyperpigmentation had higher needs for radiation dermatitis management.

Secondary cancer-incidence risk estimates for external radiotherapy and high-dose-rate brachytherapy in cervical cancer: phantom study.

This study was designed to estimate radiation-induced secondary cancer risks from high-dose-rate (HDR) brachytherapy and external radiotherapy for patients with cervical cancer based on measurements of doses absorbed by various organs. Organ doses from HDR brachytherapy and external radiotherapy were measured using glass rod dosimeters. Doses to out-of-field organs were measured at various loca-tions inside an anthropomorphic phantom. Brachytherapy-associated organ doses were measured using a specialized phantom that enabled applicator insertion, with the pelvis portion of the existing anthropomorphic phantom replaced by this new phantom. Measured organ doses were used to calculate secondary cancer risk based on Biological Effects of Ionizing Radiation (BEIR) VII models. In both treatment modalities, organ doses per prescribed dose (PD) mostly depended on the distance between organs. The locations showing the highest and lowest doses were the right kidney (external radiotherapy: 215.2 mGy; brachytherapy: 655.17 mGy) and the brain (external radiotherapy: 15.82 mGy; brachytherapy: 2.49 mGy), respectively. Organ doses to nearby regions were higher for brachytherapy than for external beam therapy, whereas organ doses to distant regions were higher for external beam therapy. Organ doses to distant treatment regions in external radiotherapy were due primarily to out-of-field radiation resulting from scattering and leakage in the gantry head. For brachytherapy, the highest estimated lifetime attributable risk per 100,000 population was to the stomach (88.6), whereas the lowest risks were to the brain (0.4) and eye (0.4); for external radiotherapy, the highest and lowest risks were to the thyroid (305.1) and brain (2.4). These results may help provide a database on the impact of radiotherapy-induced secondary cancer incidence dur-ing cervical cancer treatment, as well as suggest further research on strategies to counteract the risks of radiotherapy-associated secondary malignancies.

Does internal mammary node irradiation affect treatment outcome in clinical stage II-III breast cancer patients receiving neoadjuv ant chemotherapy?

The purpose of this study is to assess the value of internal mammary node irradiation (IMNI) in patients receiving postoperative radiotherapy after neoadjuvant chemotherapy (NAC) using modern systemic therapy. Between 2001 and 2009, 521 consecutive patients with clinical stage II-III breast cancer received NAC and postoperative radiotherapy. With a consistent policy, the treating radiation oncologist either included (N = 284) or excluded (N = 237) the internal mammary node in the treatment volume. Anthracycline- and taxane-based chemotherapy was provided to 482 (92.5 %) patients. To account for the unbalanced characteristics between the two groups, we performed propensity score matching and covariate adjustment using the propensity score. The median follow-up duration was 71 months (range 31-153 months). The 5-year disease-free survival (DFS) with and without IMNI was 81.8 and 72.7 %, respectively (p = 0.019). The benefit of IMNI varied according to patient characteristics such that it was more apparent in patients with N1-2 disease, inner/central location, and triple-negative subtype. After adjusting for all potential confounding variables, IMNI was independently associated with improved DFS (p = 0.049). The significant effect of IMNI on DFS was sustained after propensity score matching (p = 0.040) and covariate adjustment using the propensity score (p = 0.048). Symptomatic radiation pneumonitis developed in 9 (3.2 %) patients receiving IMNI. Our results indicated that IMNI was associated with a significant improvement in DFS with low toxicity rate for breast cancer patients receiving NAC. Further prospective studies are warranted to confirm the effect of IMNI in the NAC setting.

A multicenter analysis of adjuvant therapy after surgery for stage IIIC endometrial adenocarcinoma: A Korean Radiation Oncology Group study (KROG 13-17).

OBJECTIVE: To investigate whether combined chemoradiotherapy (CTRT) confers a benefit for survival outcome over radiotherapy (RT) alone after primary surgery in patients with FIGO stage IIIC endometrial adenocarcinoma. METHODS: We conducted a multicenter retrospective study of patients with surgical stage IIIC endometrial cancer from 1990 to 2011. Adjuvant RT alone was performed in 85 patients (40.3%) and adjuvant CTRT in 126 patients (59.7%). Disease-free survival (DFS) and overall survival (OS) were analyzed using Kaplan-Meier method and Cox proportional hazards model. RESULTS: Stage IIIC1 and stage IIIC2 accounted for 63% and 37%, respectively. FIGO IIIC2 had a higher recurrence rate than FIGO IIIC1 (38.5% vs. 29.3%, p=0.172). Five-year OS and DFS were lower in FIGO IIIC2 than FIGO IIIC1 (85.1% vs. 76.9%, p=0.417; 71.0% vs. 59.2%, p=0.108, respectively). Eighteen patients (13.5%) in stage IIIC1 developed PALN recurrence, whereas only one (3.3%) in stage IIIC2 had PALN recurrence (p=0.001). In multivariate analysis, predictors of DFS were parametrial invasion (HR, 3.49; 95% CI, 1.83-6.64; p<0.001), higher grade (HR, 2.78; 95% CI, 1.31-5.89; p=0.008), and >3 positive pelvic nodes (HR, 1.84; 95% CI, 1.11-3.05; p=0.019). Combined CTRT did not affect DFS or OS in IIIC1 and IIIC2 compared with RT alone. CONCLUSION: CTRT showed comparable survival outcome to RT alone. Half of relapses (46%) in stage IIIC1 occurred in PALN region, whereas relapse in stage IIIC2 primarily occurred in distant metastasis (90%). Future randomized studies are needed to determine which subgroup may be most likely to benefit from CCRT.

Correlation between location of transposed ovary and function in cervical cancer patients who underwent radical hysterectomy.

OBJECTIVE: The study investigated the association between the location of transposed ovaries and posttreatment ovarian function in patients with early cervical cancer (IB1-IIA) who underwent radical hysterectomy and ovarian transposition with or without adjuvant therapies. METHODS: Retrospective medical records were reviewed to enroll the patients with early cervical cancer who underwent ovarian transposition during radical hysterectomy at Samsung Medical Center between July 1995 and July 2012. Serum follicle-stimulating hormone (FSH) level was used as a surrogate marker for ovarian function. RESULTS: Twenty-one patients were enrolled. The median age and body mass index (BMI) were 31 years (range, 24-39 years) and 21.3 kg/m² (range, 17.7-31.2 kg/m²), respectively. The median serum FSH level after treatment was 7.9 mIU/mL (range, 2.4-143.4 mIU/mL). The median distance from the iliac crest to transposed ovaries on erect plain abdominal x-ray was 0.5 cm (range, -2.7 to 5.2 cm). In multivariate analysis, posttreatment serum FSH levels were significantly associated with the location of transposed ovaries (ß = -8.1, P = 0.032), concurrent chemoradiation (CCRT) as an adjuvant therapy (ß = 71.08, P = 0.006), and BMI before treatment (underweight: ß = -59.93, P = 0.05; overweight: ß = -40.62, P = 0.041). CONCLUSIONS: Location of transposed ovaries, adjuvant CCRT, and BMI before treatment may be associated with ovarian function after treatment. We suggest that ovaries should be transposed as highly as possible during radical hysterectomy to preserve ovarian function in young patients with early cervical cancer who might be a candidate for adjuvant CCRT and who have low BMI before treatment.

Significance of early prostate-specific antigen values after salvage radiotherapy in recurrent prostate cancer patients treated with surgery.

OBJECTIVES: To assess the use of post-salvage radiotherapy prostate-specific antigen for early prediction of biochemical failure or clinical recurrence after salvage radiotherapy in recurrent prostate cancer patients after prostatectomy. METHODS: From 2000 to 2011, 164 patients were treated with salvage radiotherapy alone for recurrent prostate cancer. Patients who received androgen deprivation therapy before or within 1 month of the termination of salvage radiotherapy were excluded. Survival analysis was carried out with: (i) a selected prostate-specific antigen reference value (0.2 ng/mL) at the second follow-up period (4 months) after salvage radiotherapy (prostate-specific antigen value over 0.2 ng/mL at post-salvage radiotherapy 4 months); and (ii) prostate-specific antigen percent decline (post-salvage radiotherapy 4 months prostate-specific antigen/pre-salvage radiotherapy prostate-specific antigen). RESULTS: The median follow-up time was 53.4 months (range 8.5-134.1 months). The 5-year clinical recurrence-free survival was 87.9%. Prostate-specific antigen percent decline of 0.45 was set as the cut-off value for clinical recurrence-free survival based on the receiver operating characteristics curve. In the multivariate analysis, a prostate-specific antigen value over 0.2 ng/mL at post-salvage radiotherapy 4 months (P = 0.013) and prostate-specific antigen percent decline ≥ 0.45 (P = 0.002) were both significant parameters predicting clinical recurrence-free survival. Otherwise, prostate-specific antigen percent decline ≥ 0.45 was the only statistically significant predictor of biochemical failure-free survival (biochemical failure-free survival after salvage radiotherapy). CONCLUSIONS: A prostate-specific antigen value over 0.2 ng/mL at post-salvage radiotherapy 4 months and prostate-specific antigen percent decline ≥ 0.45 are negative predictors of clinical recurrence-free survival after salvage radiotherapy. Prostate-specific antigen percent decline ≥ 0.45 is also associated with worse biochemical failure-free survival after salvage radiotherapy. Patients with delayed prostate-specific antigen decrease should be carefully observed for clinical recurrence.

Comparison of clinical outcomes of adenocarcinoma and adenosquamous carcinoma in uterine cervical cancer patients receiving surgical resection followed by radiotherapy: a multicenter retrospective study (KROG 13-10).

OBJECTIVE: To evaluate the prognostic influence of adenocarcinoma (AC) and adenosquamous carcinoma (ASC) in patients with FIGO stage IB-IIA cervical cancer who received radical hysterectomy followed by adjuvant radiotherapy (RT) or concurrent chemoradiotherapy (CCRT). METHODS: We analyzed 1323 patients who satisfied the following criteria: histologically proven squamous cell carcinoma (SCC), AC, or ASC of the uterine cervix; FIGO stage IB-IIA disease; no history of neoadjuvant chemotherapy; and a history of radical hysterectomy with pelvic lymph node (PLN) dissection, followed by postoperative pelvic RT at a dose ≥ 45 Gy. The median age was 50 years. Median RT dose delivered to the whole pelvis was 50.4 Gy, and 219 (16.6%) patients received brachytherapy at a median dose of 24 Gy. Concurrent chemotherapy was delivered to 492 (37.2%) patients. RESULTS: Pathologic risk factors were not different according to pathologic subtype. The median follow-up duration was 75.7 months. Locoregional recurrence-free survival, relapse-free survival (RFS), and overall survival were significantly affected by histology, tumor size, PLN metastasis, parametrial invasion, lymphovascular invasion, and deep stromal invasion. The 5-year RFS rates were 83.7%, 66.5%, and 79.6% in patients with SCC, AC, and ASC histology, respectively (P<0.0001). By multivariate analysis, AC histology was the only significant prognostic factor affecting all survival outcomes. CONCLUSIONS: AC histology was associated with poor survival outcomes in patients with FIGO stage IB-IIA cervical cancer who received adjuvant RT or CCRT. Prognosis of ASC histology was closer to that of SCC histology than that of AC histology.

Blood oxygenation level-dependent MR imaging as a predictor of therapeutic response to concurrent chemoradiotherapy in cervical cancer: a preliminary experience.

OBJECTIVES: To investigate the value of blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) as a predictor of therapeutic response in cervical cancer patients undergoing concurrent chemoradiotherapy (CCRT). METHODS: Thirty consecutive patients with biopsy-proven cervical cancer were examined by BOLD MRI before (preTx) and after CCRT (postTx). The R2* value (s(-1)) was calculated in the tumour and normal myometrium for preTx and postTx studies. Final tumour responses, as determined by changes of tumour size or volume on MRI, were correlated with tumour R2* values at preTx. RESULTS: The mean R2* values of tumours at preTx (21.1) were significantly lower than those at postTx (39.4 s(-1)) (p < 0.001), while those of normal myometrium were similar between preTx and postTx (p = 0.363). At preTx, tumour R2* values showed significantly negative correlation with final tumour size response (p = 0.022, Spearman's coefficient = -0.415). However, tumour R2* values at preTx were not associated with final tumour volume response (p = 0.069). CONCLUSIONS: BOLD MRI at 3 T, as an imaging biomarker, may have the potential to evaluate therapeutic response in cervical cancers. The association between BOLD MRI findings and CCRT responses warrants further validation. KEY POINTS: • Hypoxia in cervical cancer is an independent risk factor • BOLD MRI reflect oxygenation status of tissue adjacent to perfused microvessels • Pretreatment tumour R2* reveal negative correlation with final tumour size response • Accurate oxygenation assessment in cervical cancer may help clinical decision making.

Engineering pre-vascularized 3D tissue and rapid vascular integration with host blood vessels via co-cultured spheroids-laden hydrogel.

Recent advances in regenerative medicine and tissue engineering have enabled the biofabrication of three-dimensional (3D) tissue analogues with the potential for use in transplants and disease modeling. However, the practical use of these biomimetic tissues has been hindered by the challenge posed by reconstructing anatomical-scale micro-vasculature tissues. In this study, we suggest that co-cultured spheroids within hydrogels hold promise for regenerating highly vascularized and innervated tissues, bothin vitroandin vivo. Human adipose-derived stem cells (hADSCs) and human umbilical vein cells (HUVECs) were prepared as spheroids, which were encapsulated in gelatin methacryloyl hydrogels to fabricate a 3D pre-vascularized tissue. The vasculogenic responses, extracellular matrix production, and remodeling depending on parameters like co-culture ratio, hydrogel strength, and pre-vascularization time forin vivointegration with native vessels were then delicately characterized. The co-cultured spheroids with 3:1 ratio (hADSCs/HUVECs) within the hydrogel and with a pliable storage modulus showed the greatest vasculogenic potential, and ultimately formedin vitroarteriole-scale vasculature with a longitudinal lumen structure and a complex vascular network after long-term culturing. Importantly, the pre-vascularized tissue also showed anastomotic vascular integration with host blood vessels after transplantation, and successful vascularization that was positive for both CD31 and alpha-smooth muscle actin covering 18.6 ± 3.6µm2of the luminal area. The described co-cultured spheroids-laden hydrogel can therefore serve as effective platform for engineering 3D vascularized complex tissues.

Enhancement of Bone Tissue Regeneration with Multi-Functional Nanoparticles by Coordination of Immune, Osteogenic, and Angiogenic Responses.

Inorganic nanoparticles are promising materials for bone tissue engineering due to their chemical resemblance to the native bone structure. However, most studies are unable to capture the entirety of the defective environment, providing limited bone regenerative abilities. Hence, this study aims to develop a multifunctional nanoparticle to collectively control the defective bone niche, including immune, angiogenic, and osteogenic systems. The nanoparticles, self-assembled by biomimetic mineralization and tannic acid (TA)-mediated metal-polyphenol network (MPN), are released sustainably after the incorporation within a gelatin cryogel. The released nanoparticles display a reduction in M1 macrophages by means of reactive oxygen species (ROS) elimination. Consequently, osteoclast maturation is also reduced, which is observed by the minimal formation of multinucleated cells (0.4%). Furthermore, the proportion of M2 macrophages, osteogenic differentiation, and angiogenic potential are consistently increased by the effects of magnesium from the nanoparticles. This orchestrated control of multiple systems influences the in vivo vascularized bone regeneration in which 80% of the critical-sized bone defect is regenerated with new bones with mature lamellar structure and arteriole-scale micro-vessels. Altogether, this study emphasizes the importance of the coordinated modulation of immune, osteogenic, and angiogenic systems at the bone defect site for robust bone regeneration.

Composite Spheroid-Laden Bilayer Hydrogel for Engineering Three-Dimensional Osteochondral Tissue.

A combination of hydrogels and stem cell spheroids has been used to engineer three-dimensional (3D) osteochondral tissue, but precise zonal control directing cell fate within the hydrogel remains a challenge. In this study, we developed a composite spheroid-laden bilayer hydrogel to imitate osteochondral tissue by spatially controlled differentiation of human adipose-derived stem cells. Meticulous optimization of the spheroid-size and mechanical strength of gelatin methacryloyl (GelMA) hydrogel enables the cells to homogeneously sprout within the hydrogel. Moreover, fibers immobilizing transforming growth factor beta-1 (TGF-ß1) or bone morphogenetic protein-2 (BMP-2) were incorporated within the spheroids, which induced chondrogenic or osteogenic differentiation of cells in general media, respectively. The spheroids-filled GelMA solution was crosslinked to create the bilayer hydrogel, which demonstrated a strong interfacial adhesion between the two layers. The cell sprouting enhanced the adhesion of each hydrogel, demonstrated by increase in tensile strength from 4.8 ± 0.4 to 6.9 ± 1.2 MPa after 14 days of culture. Importantly, the spatially confined delivery of BMP-2 within the spheroids increased mineral deposition and more than threefold enhanced osteogenic genes of cells in the bone layer while the cells induced by TGF-ß1 signals were apparently differentiated into chondrocytes within the cartilage layer. The results suggest that our composite spheroid-laden hydrogel could be used for the biofabrication of osteochondral tissue, which can be applied to engineer other complex tissues by delivery of appropriate biomolecules.

Cell-homing and immunomodulatory composite hydrogels for effective wound healing with neovascularization.

Wound healing in cases of excessive inflammation poses a significant challenge due to compromised neovascularization. Here, we propose a multi-functional composite hydrogel engineered to overcome such conditions through recruitment and activation of macrophages with adapted degradation of the hydrogel. The composite hydrogel (G-TSrP) is created by combining gelatin methacryloyl (GelMA) and nanoparticles (TSrP) composed of tannic acid (TA) and Sr2+. These nanoparticles are prepared using a one-step mineralization process assisted by metal-phenolic network formation. G-TSrP exhibits the ability to eliminate reactive oxygen species and direct polarization of macrophages toward M2 phenotype. It has been observed that the liberation of TA and Sr2+ from G-TSrP actively facilitate the recruitment and up-regulation of the expression of extracellular matrix remodeling genes of macrophages, and thereby, coordinate in vivo adapted degradation of the G-TSrP. Most significantly, G-TSrP accelerates angiogenesis despite the TA's inhibitory properties, which are counteracted by the released Sr2+. Moreover, G-TSrP enhances wound closure under inflammation and promotes normal tissue formation with strong vessel growth. Genetic analysis confirms macrophage-mediated wound healing by the composite hydrogel. Collectively, these findings pave the way for the development of biomaterials that promote wound healing by creating regenerative environment.

Prophylactic supraclavicular radiotherapy after surgery in high-risk n1 breast cancer.

OBJECTIVES: To evaluate the role of prophylactic supraclavicular radiotherapy (RT) by comparing the clinical outcomes of locoregional recurrence (LRR) in high-risk N1 breast cancer. METHODS: We performed a retrospective comparison study of 250 high-risk N1 breast cancer patients treated at two institutions. Patients were considered to be high-risk when they had more than two of the following risk factors: lymphovascular invasion, extracapsular extension, metastasis to more than two axillary lymph nodes (ALNs), or level II or higher ALN metastasis. We compared two groups treated with different adjuvant RT fields for the purpose of prophylactic supraclavicular RT (SCRT). RESULTS: Among the 250 patients, 97 patients received SCRT while 153 did not. During follow-up, 32 patients (7 in the SCRT and 25 in the no-SCRT group) had recurrence, and LRR developed in 19 patients, 18 of whom had not received SCRT. In multivariate analysis, SCRT [hazard ratio (HR) 0.072; p = 0.011] and chemotherapy regimen (cyclophosphamide, Adriamycin, and taxane; TAC) were the significant prognostic factors in LRR-free survival (HR 0.385; p = 0.046), and chemotherapy regimen also showed significance for distant metastasis-free survival (HR 0.399; p = 0.037). CONCLUSIONS: Use of prophylactic SCRT may reduce the risk of LRR in patients with high-risk N1 breast cancer.

Evaluation of therapeutic response to concurrent chemoradiotherapy in patients with cervical cancer using diffusion-weighted MR imaging.

PURPOSE: To investigate the changes in apparent diffusion coefficients (ADCs) in cervical cancer patients receiving concurrent chemoradiotherapy (CCRT), and to assess the relationship between tumor ADCs or changes in tumor ADCs and final tumor responses to therapy. MATERIALS AND METHODS: Twenty-four patients with cervical cancer who received CCRT were examined with 3 Tesla (T) MRI including diffusion-weighted imaging (DWI). All patients had three serial MR examinations: before therapy (pre-Tx); at 4 weeks of therapy (mid-Tx); and 1 month after completion of therapy (post-Tx). At each examination, ADC was measured in tumors and normal gluteus muscles. Final tumor response as determined by change in tumor size or volume using MRI was correlated with tumor ADCs at each therapeutic time or changes in tumor ADCs at mid-Tx. RESULTS: From pre-Tx to post-Tx, mean tumor ADCs were 0.88, 1.30, and 1.47 × 10(-3) mm(2)/s in sequence (P < 0.001), while those of normal gluteus muscles were 1.24, 1.29, and 1.21 × 10(-3) mm(2)/s in sequence (P > 0.05). At mid-Tx, tumor ADCs and changes in tumor ADCs had a significant correlation with final tumor size responses (P = 0.029 and 0.025, respectively). However, the tumor ADC values at pre-Tx were not associated with the final tumor size response (P = 0.47). The final tumor volume response was not associated with tumor ADC at pre-Tx or mid-Tx (P > 0.05) or changes in tumor ADCs at mid-Tx (P > 0.05). CONCLUSION: DWI may have potentials in evaluating the therapeutic response to CCRT in patients with cervical cancer.

Recent Trends of Medical Expenses Associated with Radiation Therapy in Korea Based on HIRA Big Data.

PURPOSE: We aimed to determine the trends in the use of radiotherapy (RT) and the expenses associated with it in South Korea. Materials and Methods: The statistical data of the claims and reimbursement records provided on the Health and Insurance Review and Assessment Service website were utilized. This included information such as the number of patients, fractions, medical expenses according to treatment codes, in/outpatient, sex, age, and regions of hospitals. We analyzed data from 2016 to 2020. RESULTS: With a growing RT infrastructure and an increase in the number of radiation oncologists, the expenses for RT were 605.5 million USD in 2020, which had increased 1.5 times from 394.7 million USD in 2016. This growth was mainly because of the increased usage of advanced RT techniques. Furthermore, the proportion of intensity-modulated radiation therapy (IMRT) expenses in the total expenses increased by 1.6 times from 48.8% in 2016 to 76.9% in 2020. Advanced techniques were used more commonly in older individuals or children. However, the proportion of IMRT expenses increased mostly in young women. Additionally, geographical differences in RT use and expense were observed, although the gap in the IMRT fractions decreased among the regions. CONCLUSION: Recent medical expenses associated with RT in Korea have increased in tandem with technological advances and changes in demographics.