Low-Dose Ionizing Radiation Modulates Microglia Phenotypes in the Models of Alzheimer's Disease.

Alzheimer's disease (AD) is the most common type of dementia. AD involves major pathologies such as amyloid-ß (Aß) plaques and neurofibrillary tangles in the brain. During the progression of AD, microglia can be polarized from anti-inflammatory M2 to pro-inflammatory M1 phenotype. The activation of triggering receptor expressed on myeloid cells 2 (TREM2) may result in microglia phenotype switching from M1 to M2, which finally attenuated Aß deposition and memory loss in AD. Low-dose ionizing radiation (LDIR) is known to ameliorate Aß pathology and cognitive deficits in AD; however, the therapeutic mechanisms of LDIR against AD-related pathology have been little studied. First, we reconfirm that LDIR (two Gy per fraction for five times)-treated six-month 5XFAD mice exhibited (1) the reduction of Aß deposition, as reflected by thioflavins S staining, and (2) the improvement of cognitive deficits, as revealed by Morris water maze test, compared to sham-exposed 5XFAD mice. To elucidate the mechanisms of LDIR-induced inhibition of Aß accumulation and memory loss in AD, we examined whether LDIR regulates the microglial phenotype through the examination of levels of M1 and M2 cytokines in 5XFAD mice. In addition, we investigated the direct effects of LDIR on lipopolysaccharide (LPS)-induced production and secretion of M1/M2 cytokines in the BV-2 microglial cells. In the LPS- and LDIR-treated BV-2 cells, the M2 phenotypic marker CD206 was significantly increased, compared with LPS- and sham-treated BV-2 cells. Finally, the effect of LDIR on M2 polarization was confirmed by detection of increased expression of TREM2 in LPS-induced BV2 cells. These results suggest that LDIR directly induced phenotype switching from M1 to M2 in the brain with AD. Taken together, our results indicated that LDIR modulates LPS- and Aß-induced neuroinflammation by promoting M2 polarization via TREM2 expression, and has beneficial effects in the AD-related pathology such as Aß deposition and memory loss.

Neuroprotective and Anti-Inflammatory Effects of Low-Moderate Dose Ionizing Radiation in Models of Alzheimer's Disease.

Alzheimer's disease (AD) is the most common cause of dementia. The neuropathological features of AD include amyloid-ß (Aß) deposition and hyperphosphorylated tau accumulation. Although several clinical trials have been conducted to identify a cure for AD, no effective drug or treatment has been identified thus far. Recently, the potential use of non-pharmacological interventions to prevent or treat AD has gained attention. Low-dose ionizing radiation (LDIR) is a non-pharmacological intervention which is currently being evaluated in clinical trials for AD patients. However, the mechanisms underlying the therapeutic effects of LDIR therapy have not yet been established. In this study, we examined the effect of LDIR on Aß accumulation and Aß-mediated pathology. To investigate the short-term effects of low-moderate dose ionizing radiation (LMDIR), a total of 9 Gy (1.8 Gy per fraction for five times) were radiated to 4-month-old 5XFAD mice, an Aß-overexpressing transgenic mouse model of AD, and then sacrificed at 4 days after last exposure to LMDIR. Comparing sham-exposed and LMDIR-exposed 5XFAD mice indicated that short-term exposure to LMDIR did not affect Aß accumulation in the brain, but significantly ameliorated synaptic degeneration, neuronal loss, and neuroinflammation in the hippocampal formation and cerebral cortex. In addition, a direct neuroprotective effect was confirmed in SH-SY5Y neuronal cells treated with Aß1-42 (2 µM) after single irradiation (1 Gy). In BV-2 microglial cells exposed to Aß and/or LMDIR, LMDIR therapy significantly inhibited the production of pro-inflammatory molecules and activation of the nuclear factor-kappa B (NF-κB) pathway. These results indicate that LMDIR directly ameliorated neurodegeneration and neuroinflammation in vivo and in vitro. Collectively, our findings suggest that the therapeutic benefits of LMDIR in AD may be mediated by its neuroprotective and anti-inflammatory effects.

Dosimetric analysis of six whole-breast irradiation techniques in supine and prone positions.

In breast cancer radiation therapy, minimizing radiation-related risks and toxicity is vital for improving life expectancy. Tailoring radiotherapy techniques and treatment positions can reduce radiation doses to normal organs and mitigate treatment-related toxicity. This study entailed a dosimetric comparison of six different external beam whole-breast irradiation techniques in both supine and prone positions. We selected fourteen breast cancer patients, generating six treatment plans in both positions per patient. We assessed target coverage and organs at risk (OAR) doses to evaluate the impact of treatment techniques and positions. Excess absolute risk was calculated to estimate potential secondary cancer risk in the contralateral breast, ipsilateral lung, and contralateral lung. Additionally, we analyzed the distance between the target volume and OARs (heart and ipsilateral lung) while considering the treatment position. The results indicate that prone positioning lowers lung exposure in X-ray radiotherapy. However, particle beam therapies (PBTs) significantly reduce the dose to the heart and ipsilateral lung regardless of the patient's position. Notably, negligible differences were observed between arc-delivery and static-delivery PBTs in terms of target conformity and OAR sparing. This study provides critical dosimetric evidence to facilitate informed decision-making regarding treatment techniques and positions.

Comparative efficacy of Jaungo, a traditional herbal ointment, and a water-in-oil type non-steroidal moisturizer for radiation-induced dermatitis in patients with breast cancer: a prospective, randomized, single-blind, pilot study.

Background: Radiation-induced dermatitis (RID) is one of the most prevalent side-effects of conventional cancer therapies; however, there is no standard treatment for its prevention. Therefore, this study aimed to evaluate the comparative efficacy and safety of Jaungo (mainly composed of Lithospermum erythrorhizon Siebold & Zucc. and Angelica sinensis (Oliv.) Diel) and the water-in-oil-type non-steroidal moisturizer for the prevention of RID in patients with breast cancer (BC). Methods: This is a prospective, single-blind, pilot randomized controlled trial. Between March 2021 and July 2022, 50 patients were randomly selected to use Jaungo or the moisturizer while undergoing postoperative radiation therapy (RT). Assessments were conducted nine times-every week while the patients underwent RT and 2 weeks after the end of therapy. The primary outcome was the incidence rate of RID grade ≥2. The secondary outcomes were the incidence rate of maximum grade RID, time to RID onset, RID-related quality of life (QOL) score, pain intensity, and adverse events. Results: The incidence rate of RID grade ≥2 was 24.0% and 20.0% in the Jaungo and the moisturizer groups, respectively, with no significant difference between the groups (p = 0.733). Regarding the secondary outcomes, the incidence rate of maximum grade RID (p = 0.890), mean time to RID onset (p = 0.092), cumulative incidence rate of RID (p = 0.280), RID-related QOL score, and maximum pain intensity (p = 0.844) also did not differ significantly between the groups. None of the subjects in either group experienced severe adverse effects, although one participant in the moisturizer group had mild fever and insomnia. Conclusion: These findings suggest that Jaungo has preventive efficacy without severe side-effects against RID in patients with BC that is comparable to that of the water-in-oil type non-steroidal moisturizer. Further extensive randomized controlled trials with larger sample sizes are warranted to validate our findings. Clinical Trial Registration: Clinical Research Information Service (CRIS), https://cris.nih.go.kr, identifier KCT0005971.

Corrigendum: Comparative efficacy of Jaungo, a traditional herbal ointment, and a water-in-oil type non-steroidal moisturizer for radiation-induced dermatitis in patients with breast cancer: a prospective, randomized, single-blind, pilot study.

[This corrects the article DOI: 10.3389/fphar.2023.1216668.].

Clinicopathological Outcomes in Patients With Locally Advanced Rectal Cancer Undergoing Preoperative Short-Versus Long-course Chemoradiotherapy With Delayed Surgery.

BACKGROUND/AIM: We aimed to compare the clinicopathological outcomes in patients with locally advanced rectal cancer after short- or long-course concurrent chemoradiotherapy (CCRT) followed by delayed surgery. PATIENTS AND METHODS: The records of 94 patients with cT3-4N0-2M0 rectal cancer who received CCRT between 2010 and 2017 were reviewed. Short-course radiotherapy (RT) was delivered with a median total dose of 25 Gy in five fractions (n=27), and long-course RT was delivered with a median total dose of 50.4 Gy in 28 fractions (n=67). The following concurrent chemotherapy regimens were administered: 5-fluorouracil plus leucovorin in 58 and capecitabine in 24; in 12 cases agents were unknown. The median interval between CCRT and surgery was 8 weeks. Adjuvant chemotherapy was administered after surgery in 80 patients (5-fluorouracil plus leucovorin, n=54; capecitabine, n=9; other, n=14; and unknown, n=3). Propensity-score matching analysis was conducted. RESULTS: The median follow-up duration was 4.3 years. There were no statistically significant differences between the short- and long-course RT groups in sphincter preservation (85.2% vs. 92.5%, p=0.478), pathological complete remission (18.5% vs. 14.9%, p=0.905), downstaging (44.4% vs. 26.9%, p=0.159), and negative circumferential resection margin (92.6% vs. 89.6%, p=0.947) rates. No differences were found in survival outcomes between the short- and long-course groups at 3 years (overall survival: 91.8% vs. 88.1%, p=0.790; disease-free survival, 75.2% vs. 72.5%, p=0.420; locoregional relapse-free survival, 90.5% vs. 98.4%, p=0.180; and distant metastasis-free survival, 79.6% vs. 73.5%, p=0.490). Similar results were observed after PSM. CONCLUSION: Clinically, short-course CCRT may be a feasible alternative to long-course CCRT in patients with locally advanced rectal cancer.

Evaluation of Efficacy and Safety Using Low Dose Radiation Therapy with Alzheimer's Disease: A Protocol for Multicenter Phase II Clinical Trial.

BACKGROUND: Alzheimer's disease (AD), the most common cause of dementia, is a neurodegenerative disease resulting from extracellular and intracellular deposits of amyloid-ß (Aß) and neurofibrillary tangles in the brain. Although many clinical studies evaluating pharmacological approaches have been conducted, most have shown disappointing results; thus, innovative strategies other than drugs have been actively attempted. OBJECTIVE: This study aims to explore low-dose radiation therapy (LDRT) for the treatment of patients with AD based on preclinical evidence, case reports, and a small pilot trial in humans. METHODS: This study is a phase II, multicenter, prospective, single-blinded, randomized controlled trial that will evaluate the efficacy and safety of LDRT to the whole brain using a linear accelerator in patients with mild AD. Sixty participants will be randomly assigned to three groups: experimental I (24 cGy/6 fractions), experimental II (300 cGy/6 fractions), or sham RT group (0 cGy/6 fractions). During LDRT and follow-up visits after LDRT, possible adverse events will be assessed by the physician's interview and neurological examinations. Furthermore, the effectiveness of LDRT will be measured using neurocognitive function tests and imaging tools at 6 and 12 months after LDRT. We will also monitor the alterations in cytokines, Aß42/Aß40 ratio, and tau levels in plasma. Our primary endpoint is the change in cognitive function test scores estimated by the Alzheimer's Disease Assessment Scale-Korea compared to baseline after 6 months of LDRT. CONCLUSIONS: This study is registered at ClinicalTrials.gov [NCT05635968] and is currently recruiting patients. This study will provide evidence that LDRT is a new treatment strategy for AD.

Dynamic alterations in PD-1/PD-L1 expression level and immune cell profiles based on radiation response status in mouse tumor model.

Introduction: Based on the immunologic effects of anti-cancer treatment and their therapeutic implications, we evaluated radiotherapy (RT)-induced dynamic alterations in programmed death-1 (PD-1)/PD ligand-1 (PD-L1) expression profiles. Methods: Local RT with 2 Gy × 5 or 7.5 Gy × 1 was administered to the CT26 mouse model. Thereafter, tumors were resected and evaluated at the following predefined timepoints according to radiation response status: baseline, early (immediately after RT), middle (beginning of tumor shrinkage), late (stable status with RT effect), and progression (tumor regrowth). PD-1/PD-L1 activity and related immune cell profiles were quantitatively assessed. Results: RT upregulated PD-L1 expression in tumor cells from the middle to late phase; however, the levels subsequently decreased to levels comparable to baseline in the progression phase. RT with 2 Gy × 5 induced a higher frequency of PD-L1+ myeloid-derived suppressor cells, with a lesser degree of tumor regression, compared to 7.5 Gy. The proportion of PD-1+ and interferon (IFN)-γ+CD8α T cells continued to increase. The frequency of splenic PD-1+CD8+ T cells was markedly elevated, and was sustained longer with 2 Gy × 5. Based on the transcriptomic data, RT stimulated the transcription of immune-related genes, leading to sequentially altered patterns. Discussion: The dynamic alterations in PD-1/PD-L1 expression level were observed according to the time phases of tumor regression. This study suggests the influence of tumor cell killing and radiation dosing strategy on the tumor immune microenvironment.

Clinical evaluation of toll-like receptor-5 agonist for radiation-induced oral mucositis in beagle dogs.

This study aimed to evaluate the clinical safety and validate the radiomitigative effect of KMRC011, against radiation-induced oral mucositis in beagle dogs. Clinical safety was evaluated by assessing tolerability, complete blood tests, and plasma biochemistry after drug administration. The radiomitigative effect of KMRC011 was evaluated macropathologically and histopathologically after inducing oral mucositis iatrogenically using 20 Gy irradiation. The plasma concentration of interleukin-6 was measured via enzyme-linked immunosorbent assay, as a biomarker of KMRC011 bioreactivity. Decreased tolerability, increased neutrophil count, hepatic enzyme concentration, C-reactive protein concentration, and interleukin-6 concentration after the administration was observed and ceased within 24 h without additional treatment. Although all animals included in the present study developed severe mucositis in the late course of the study, animals administered KMRC011 showed less erythema, ulcer, inflammatory infiltration. These results suggest that KMRC011 may be used as an adjuvant for radiotherapy without severe adverse effects, especially during short-term radiotherapy, such as hypofractionated radiotherapy or stereotactic radiotherapy.

Clinical Approach of Low-Dose Whole-Brain Ionizing Radiation Treatment in Alzheimer's Disease Dementia Patients.

Our research team recently published two relevant papers. In one study, we have seen the acute effect of low-dose ionizing irradiation (LDIR) did not reduce the amyloid-ß (Aß) protein concentration in brain tissue, yet significantly improved synaptic degeneration and neuronal loss in the hippocampus and cerebral cortex. Surprisingly, in another study, we could see late effect that the LDIR-treated mice showed significantly improved learning and memory skills compared with those in the sham group. In addition, Aß concentrations were significantly decreased in brain tissue. Furthermore, the pro-inflammatory cytokine tumor necrosis factor-α was decreased and the anti-inflammatory cytokine transforming growth factor-ß was increased in the brain tissue of 5xFAD mice treated with LDIR. Definitive clinical results for the safety and efficacy of LDIR have not yet been published and, despite the promising outcomes reported during preclinical studies, LDIR can only be applied to patients with Alzheimer's disease dementia when clinical results are made available. In addition, in the case of LDIR, additional large-scale clinical studies are necessary to determine the severity of Alzheimer's disease dementia, indications for LDIR, the total dose to be irradiated, fraction size, and intervals of LDIR treatment. The purpose of this review is to summarize the mechanism of LDIR based on existing preclinical results in a way that is useful for conducting subsequent clinical research.

Comparative Efficacy of Jaungo, A Traditional Herbal Ointment, and the Water-in-Oil Type Non-Steroidal Moisturizer for Radiation-Induced Dermatitis in Patients With Breast Cancer: A Study Protocol for a Prospective, Randomized, Single-Blinded, Pilot Study.

Background: Radiation-induced dermatitis (RID) is a common complication of radiation therapy (RT). Although it has a high prevalence and can even trigger the premature end of conventional cancer therapies, there is no standard management. This study aims to evaluate whether topical use of Jaungo (Shiunko), a traditional herbal ointment mainly composed of Lithospermi radix and Angelica sinensis, could reduce RID compared to the water-in-oil type non-steroidal moisturizer in patients with breast cancer. Methods: This is a prospective, single-blinded, randomized controlled pilot trial that investigates the effect of topical application of Jaungo for the prevention of RID in postoperative breast cancer patients scheduled for RT, in comparison with the non-steroidal moisturizer, with a random distribution of 50 patients across the two groups. RT will be administered for 5-7 weeks with a biological equivalent dose (BED10) of 60 Gy or more, and the interventions will be applied 3 times a day during RT duration. Participants will be assessed a total of nine times, including eight visits during the period of RT and one visit at a 2-week follow-up period after the end of treatment. The incidence and severity of RID, quality of life, skin reaction symptoms, and maximum pain related to RID will be measured. The incidence rate of grade 2 or higher RID using the Radiation Therapy Oncology Group (RTOG) in the two groups will be statistically compared as the primary outcome. The types and frequencies of adverse events will be also collected and evaluated. All assessments will be performed by independent radiology oncologists. Discussion: This trial is currently ongoing and is recruiting. This study will determine the preventive efficacy of Jaungo in RID with postoperative breast cancer patients and provide evidence in traditional Korean medicine clinical practice.

p62/SQSTM1-induced caspase-8 aggresomes are essential for ionizing radiation-mediated apoptosis.

The autophagy-lysosome pathway and apoptosis constitute vital determinants of cell fate and engage in a complex interplay in both physiological and pathological conditions. Central to this interplay is the archetypal autophagic cargo adaptor p62/SQSTM1/Sequestosome-1 which mediates both cell survival and endoplasmic reticulum stress-induced apoptosis via aggregation of ubiquitinated caspase-8. Here, we investigated the role of p62-mediated apoptosis in head and neck squamous cell carcinoma (HNSCC), which can be divided into two groups based on human papillomavirus (HPV) infection status. We show that increased autophagic flux and defective apoptosis are associated with radioresistance in HPV(-) HNSCC, whereas HPV(+) HNSCC fail to induce autophagic flux and readily undergo apoptotic cell death upon radiation treatments. The degree of radioresistance and tumor progression of HPV(-) HNSCC respectively correlated with autophagic activity and cytosolic levels of p62. Pharmacological activation of the p62-ZZ domain using small molecule ligands sensitized radioresistant HPV(-) HNSCC cells to ionizing radiation by facilitating p62 self-polymerization and sequestration of cargoes leading to apoptosis. The self-polymerizing activity of p62 was identified as the essential mechanism by which ubiquitinated caspase-8 is sequestered into aggresome-like structures, without which irradiation fails to induce apoptosis in HNSCC. Our results suggest that harnessing p62-dependent sequestration of ubiquitinated caspase-8 provides a novel therapeutic avenue in patients with radioresistant tumors.

Dummy Run of Quality Assurance Program before Prospective Study of Hippocampus-Sparing Whole-Brain Radiotherapy and Simultaneous Integrated Boost for Multiple Brain Metastases from Non-small Cell Lung Cancer: Korean Radiation Oncology Group (KROG) 17-06 Study.

PURPOSE: Lung Cancer Subcommittee of Korean Radiation Oncology Group (KROG) has recently launched a prospective clinical trial (KROG 17-06) of hippocampus-sparing whole brain radiotherapy (HS-WBRT) with simultaneous integrated boost (SIB) in treating multiple brain metastases from non-small cell lung cancer. In order to improve trial quality, dummy run studies among the participating institutions were designed. This work reported the results of two-step dummy run procedures of the KROG 17-06 study. MATERIALS AND METHODS: Two steps tested hippocampus contouring variability and radiation therapy planning compliance. In the first step, the variation of the hippocampus delineation was investigated for two representative cases using the Dice similarity coefficients. In the second step, the participating institutions were requested to generate a HS-WBRT with SIB treatment plan for another representative case. The compliance of the treatment plans to the planning protocol was evaluated. RESULTS: In the first step, the median Dice similarity coefficients of the hippocampus contours for two other dummy run cases changed from 0.669 (range, 0.073 to 0.712) to 0.690 (range, 0.522 to 0.750) and from 0.291 (range, 0.219 to 0.522) to 0.412 (range, 0.264 to 0.598) after providing the hippocampus contouring feedback. In the second step, with providing additional plan priority and extended dose constraints to the target volumes and normal structures, we observed the improved compliance of the treatment plans to the planning protocol. CONCLUSION: The dummy run studies demonstrated the notable inter-institutional variability in delineating the hippocampus and treatment plan generation, which could be decreased through feedback from the trial center.

Preoperative short- vs. long-course chemoradiotherapy with delayed surgery for locally advanced rectal cancer.

PURPOSE: To compare the clinical outcomes between short-course chemoradiotherapy (CRT) and long-course CRT with delayed surgery in locally advanced rectal cancer patients. RESULTS: From 2010 to 2015, 19 patients were treated with short-course CRT and 53 patients were treated with LCRT. The sphincter-saving rate (89.5% vs. 94.3%, short-course CRT vs. long-course CRT), pathologic complete remission (21.1% vs. 13.2%), downstaging (47.4% vs. 26.4%), and treatment complications including anastomotic site leakage, bowel adhesion, and hematologic toxicity associated with short-course CRT were not significantly different from those associated with long-course CRT. 2-year overall survival was 90.0% and 91.2% (p = 0.448), respectively. METHODS AND MATERIALS: 72 patients with stage cT3-4N0-2M0 rectal cancer participated in a multicenter study. Short-course CRT treatment was as follows: a total of 25 Gy of radiotherapy was delivered in 5 equal doses with intensity modulated radiation therapy. Chemotherapy was consisted of Leucovorin 400 mg/m2 administered by bolus injection on day 1 and 5-Fluouracil 1200 mg/m2 given by continuous infusion on days 1 and 2. An additional three cycles of chemotherapy were administered before the surgery. Long-course CRT treatment was as follows: a total of 50.4 Gy of radiotherapy was delivered in 28 equal doses. Chemotherapy consisted of a bolus injection of 5-Fluouracil + Leucovorin during the first and last week of radiotherapy. Surgery was performed 6-8 weeks after completion of radiotherapy in both groups. CONCLUSIONS: Preoperative short-course CRT is an effective and safe modality. It is clinically comparable to long-course CRT in locally advanced rectal cancer.

Angiosarcoma after excisional surgery for chronic lymphedema.

Angiosarcoma is a rare soft tissue sarcoma of endothelial cell origin. It can arise from the endothelium of lymphatics (lymphangiosarcoma) or blood vessels (hemangiosarcoma). Chronic lymphedema of any origin is associated with its development. Few cases have been reported after surgical procedures for lymphedema. Here, we report one case of angiosarcoma that developed 15 months after excisional surgery for lymphedema. In spite of radical surgery and adjuvant chemoradiotherapy, the patient died of multiple lung metastases and pleural effusion 13 months later.

Comparison of the extent of hippocampal sparing according to the tilt of a patient's head during WBRT using linear accelerator-based IMRT and VMAT.

In this paper, we report the results of our investigation into whole brain radiotherapy (WBRT) using linear accelerator-based intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) in lung cancer patients with a high risk of metastasis to the brain. Specifically, we assessed the absorbed dose and the rate of adverse effects for several organs at risk (OAR), including the hippocampus, according to the tilt of a patient's head. We arbitrarily selected five cases where measurements were made with the patients' heads tilted forward and five cases without such tilt. We set the entire brain as the planning target volume (PTV), and the hippocampi, the lenses, the eyes, and the cochleae as the main OAR, and formulated new plans for IMRT (coplanar, non-coplanar) and VMAT (coplanar, non-coplanar). Using the dose-volume histogram (DVH), we calculated and compared the effective uniform dose (EUD), normal tissue complication probability (NTCP) of the OAR and the mean and the maximum doses of hippocampus. As a result, if the patient tilted the head forward when receiving the Linac-based treatment, for the same treatment effect in the PTV, we confirmed that a lower dose entered the OAR, such as the hippocampus, eye, lens, and cochlea. Moreover, the damage to the hippocampus was expected to be the least when receiving coplanar VMAT with the head tilted forward. Accordingly, if patients tilt their heads forward when undergoing Linac-based WBRT, we anticipate that a smaller dose would be transmitted to the OAR, resulting in better quality of life following treatment.

Estimation of the risk of secondary malignancy arising from whole-breast irradiation: comparison of five radiotherapy modalities, including TomoHDA.

The risk of secondary cancer from radiation treatment remains a concern for long-term breast cancer survivors, especially those treated with radiation at the age younger than 45 years. Treatment modalities optimally maximize the dose delivery to the tumor while minimizing radiation doses to neighboring organs, which can lead to secondary cancers. A new TomoTherapy treatment machine, TomoHDATM, can treat an entire breast with two static but intensity-modulated beams in a slice-by-slice fashion. This feature could reduce scattered and leakage radiation doses. We compared the plan quality and lifetime attributable risk (LAR) of a second malignancy among five treatment modalities: three-dimensional conformal radiation therapy, field-in-field forward-planned intensity-modulated radiation therapy, inverse-planned intensity-modulated radiation therapy (IMRT), volumetric modulated arc therapy, and TomoDirect mode on the TomoHDA system. Ten breast cancer patients were selected for retrospective analysis. Organ equivalent doses, plan characteristics, and LARs were compared. Out-of-field organ doses were measured with radio-photoluminescence glass dosimeters. Although the IMRT plan provided overall better plan quality, including the lowest probability of pneumonitis, it caused the second highest LAR. The TomoTherapy plan provided plan quality comparable to the IMRT plan and posed the lowest total LAR to neighboring organs. Therefore, it can be a better treatment modality for younger patients who have a longer life expectancy.

Development of new on-line statistical program for the Korean Society for Radiation Oncology.

PURPOSE: To develop new on-line statistical program for the Korean Society for Radiation Oncology (KOSRO) to collect and extract medical data in radiation oncology more efficiently. MATERIALS AND METHODS: The statistical program is a web-based program. The directory was placed in a sub-folder of the homepage of KOSRO and its web address is http://www.kosro.or.kr/asda. The operating systems server is Linux and the webserver is the Apache HTTP server. For database (DB) server, MySQL is adopted and dedicated scripting language is the PHP. Each ID and password are controlled independently and all screen pages for data input or analysis are made to be friendly to users. Scroll-down menu is actively used for the convenience of user and the consistence of data analysis. RESULTS: Year of data is one of top categories and main topics include human resource, equipment, clinical statistics, specialized treatment and research achievement. Each topic or category has several subcategorized topics. Real-time on-line report of analysis is produced immediately after entering each data and the administrator is able to monitor status of data input of each hospital. Backup of data as spread sheets can be accessed by the administrator and be used for academic works by any members of the KOSRO. CONCLUSION: The new on-line statistical program was developed to collect data from nationwide departments of radiation oncology. Intuitive screen and consistent input structure are expected to promote entering data of member hospitals and annual statistics should be a cornerstone of advance in radiation oncology.

Postoperative adjuvant chemotherapy and radiotherapy for stage II and III non-small cell lung cancer (NSCLC).

The role of postoperative adjuvant chemo-radiotherapy in the treatment of patients with non-small cell lung cancer (NSCLC) remains unclear. This study was undertaken to evaluate the survival outcomes, relapse patterns, prognostic factors and complications of postoperative adjuvant MVP chemotherapy and radiotherapy. The study involved some 96 patients who had undergone curative resection of stage II and III NSCLC between 1991 and 1996. Among these, 94 patients who completed their adjuvant treatment were analyzed. Surgery consisted of pneumonectomy (33%), single lobectomy (54%) or bilobectomy (13%). Within 4 weeks of curative resection, two cycles of MVP chemotherapy (mitomycinC 8 mg/m(2), vinblastine 8 mg/m(2), cisplatin 60 mg/m(2)) were started at 4 weeks intervals. Conventionally fractionated radiotherapy was given 3 weeks after chemotherapy to a total dose of 50 Gy in completely resected patients and 55-60 Gy in patients with positive resection margins. The TNM classification of the AJCC, as revised in 1997, was used for pathologic staging. The number of patients at AJCC stages IIa, IIb, IIIa, and IIIb were four, 40, 45, and five, respectively. A pathologically positive bronchial resection margin was found in nine patients. At the time of analysis, death was recorded in 29 patients (31%), though five had died without evidence of lung cancer. Overall 2, 3, and 5-year-survival rates for all patients were 74.2, 70.2, and 65%, respectively, and locoregional disease-free survival (LRDFS) rates were 88.6, 83.7, 74.3%, at 2, 3, and 5-years, distant metastasis disease-free survival (DMDFS) rates were 67.7, 65.0, and 63.6%, respectively. In the multivariate model, a primary tumor size of more than 5 cm and the level of pathologically positive nodes were found to be associated with poor overall survival, LRDFS and DMDFS. Although positive bronchial resection margin affected overall survival, LRDFS and DMDFS were unaffected. With respect to the first site of relapse, distant metastasis occurred more frequently (N=33, 35%) than locoregional recurrence (N=15, 16%). Grade 3 esophagitis in two patients and weight loss of more than 10% in five patients were observed during adjuvant treatment. Grade 4 pulmonary toxicity was observed in one patient after radiotherapy and this patient ultimately died 5 months after treatment. The postoperative adjuvant MVP chemotherapy and radiotherapy regimen showed relatively low locoregional recurrence and distant metastasis rates and good survival with acceptable toxicity. A prospective randomized trial, which compares this regimen to surgery alone or postoperative adjuvant radiotherapy is needed.

Risk of secondary cancers from scattered radiation during intensity-modulated radiotherapies for hepatocellular carcinoma.

PURPOSE: To evaluate and compare the risks of secondary cancers from therapeutic doses received by patients with hepatocellular carcinoma (HCC) during intensity-modulated radiotherapy (IMRT), volumetric arc therapy (VMAT), and tomotherapy (TOMO). METHODS: Treatments for five patients with hepatocellular carcinoma (HCC) were planned using IMRT, VMAT, and TOMO. Based on the Biological Effects of Ionizing Radiation VII method, the excess relative risk (ERR), excess absolute risk (EAR), and lifetime attributable risk (LAR) were evaluated from therapeutic doses, which were measured using radiophotoluminescence glass dosimeters (RPLGDs) for each organ inside a humanoid phantom. RESULTS: The average organ equivalent doses (OEDs) of 5 patients were measured as 0.23, 1.18, 0.91, 0.95, 0.97, 0.24, and 0.20 Gy for the thyroid, lung, stomach, liver, small intestine, prostate (or ovary), and rectum, respectively. From the OED measurements, LAR incidence were calculated as 83, 46, 22, 30, 2 and 6 per 10(4) person for the lung, stomach, normal liver, small intestine, prostate (or ovary), and rectum. CONCLUSIONS: We estimated the secondary cancer risks at various organs for patients with HCC who received different treatment modalities. We found that HCC treatment is associated with a high secondary cancer risk in the lung and stomach.