Assessment of deep learning-based auto-contouring on interobserver consistency in target volume and organs-at-risk delineation for breast cancer: Implications for RTQA program in a multi-institutional study.

PURPOSE: To quantify interobserver variation (IOV) in target volume and organs-at-risk (OAR) contouring across 31 institutions in breast cancer cases and to explore the clinical utility of deep learning (DL)-based auto-contouring in reducing potential IOV. METHODS AND MATERIALS: In phase 1, two breast cancer cases were randomly selected and distributed to multiple institutions for contouring six clinical target volumes (CTVs) and eight OAR. In Phase 2, auto-contour sets were generated using a previously published DL Breast segmentation model and were made available for all participants. The difference in IOV of submitted contours in phases 1 and 2 was investigated quantitatively using the Dice similarity coefficient (DSC) and Hausdorff distance (HD). The qualitative analysis involved using contour heat maps to visualize the extent and location of these variations and the required modification. RESULTS: Over 800 pairwise comparisons were analysed for each structure in each case. Quantitative phase 2 metrics showed significant improvement in the mean DSC (from 0.69 to 0.77) and HD (from 34.9 to 17.9 mm). Quantitative analysis showed increased interobserver agreement in phase 2, specifically for CTV structures (5-19 %), leading to fewer manual adjustments. Underlying IOV differences causes were reported using a questionnaire and hierarchical clustering analysis based on the volume of CTVs. CONCLUSION: DL-based auto-contours improved the contour agreement for OARs and CTVs significantly, both qualitatively and quantitatively, suggesting its potential role in minimizing radiation therapy protocol deviation.

Comparison of initial and sequential salvage brain-directed treatment in patients with 1-4 vs. 5-10 brain metastases from breast cancer (KROG 16-12).

PURPOSE: We aimed to compare the initial and salvage brain-directed treatment and overall survival (OS) between patients with 1-4 brain metastases (BMs) and those with 5-10 from breast cancer (BC). We also organized a decision tree to select the initial whole-brain radiotherapy (WBRT) for these patients. METHODS: Between 2008 and 2014, 471 patients were diagnosed with 1-10 BMs. They were divided into two groups based on the number of BM: 1-4 BMs (n = 337) and 5-10 BMs (n = 134). Median follow-up duration was 14.0 months. RESULTS: Stereotactic radiosurgery (SRS)/fractionated stereotactic radiotherapy (FSRT) was the most common treatment modality (n = 120, 36%) in the 1-4 BMs group. In contrast, 80% (n = 107) of patients with 5-10 BMs were treated with WBRT. The median OS of the entire cohort, 1-4 BMs, and 5-10 BMs was 18.0, 20.9, and 13.9 months, respectively. In the multivariate analysis, the number of BM and WBRT were not associated with OS, whereas triple-negative BC and extracranial metastasis decreased OS. Physicians determined the initial WBRT based on four variables in the following order: number and location of BM, primary tumor control, and performance status. Salvage brain-directed treatment (n = 184), mainly SRS/FSRT (n = 109, 59%), prolonged OS by a median of 14.3 months. CONCLUSION: The initial brain-directed treatment differed notably according to the number of BM, which was chosen based on four clinical factors. In patients with ≤ 10 BMs, the number of BM and WBRT did not affect OS. The major salvage brain-directed treatment modality was SRS/FSRT and increased OS.

Target movement according to cervical lymph node level in head and neck cancer and its clinical significance.

PURPOSE: To evaluate set-up error for head and neck cancer (HNC) patients according to each neck lymph node (LN) level. And clinical factors affecting set-up error were analyzed. MATERIALS AND METHODS: Reference points (RP1, RP2, RP3, and RP4) representing neck LN levels I to IV were designated. These RP were contoured on simulation computed tomography (CT) and cone-beam CT of 89 HNC patients with the same standard. After image registration was performed, movement of each RP was measured. Univariable logistic regression analyses were performed to analyze clinical factors related to measured movements. RESULTS: The mean value of deviation of all axes was 1.6 mm, 1.3 mm, 1.8 mm, and 1.5 mm for RP1, RP2, RP3, and RP4, respectively. Deviation was over 3 mm in 24 patients. Movement of more than 3 mm was observed only in RP1 and RP3. In RP1, it was related to bite block use. Movement exceeding 3 mm was most frequently observed in RP3. Primary tumor and metastatic LN volume change were clinical factors related to the RP3 movement. CONCLUSION: Planning target volume margin of 4 mm for neck LN level I, 3 mm for neck LN level II, 5 mm for neck LN level III, and 3 mm for neck LN level IV was required to include all movements of each LN level. In patients using bite block, changes in primary tumor volume, and metastatic LN volume were related to significant movement.

Mebendazole Increases Anticancer Activity of Radiotherapy in Radiotherapy-Resistant Triple-Negative Breast Cancer Cells by Enhancing Natural Killer Cell-Mediated Cytotoxicity.

Breast cancer is the most commonly diagnosed cancer worldwide and ranks first in terms of both prevalence and cancer-related mortality in women. In this study, we aimed to evaluate the anticancer effect of mebendazole (MBZ) and radiotherapy (RT) concomitant use in triple-negative breast cancer (TNBC) cells and elucidate the underlying mechanisms of action. Breast cancer mouse models and several types of breast cancer cells, including TNBC-derived RT-resistant (RT-R) MDA-MB-231 cells, were treated with MBZ and/or RT. In mice, changes in body weight, renal and liver toxicity, tumor volume, and number of lung metastases were determined. In cells, cell viability, colony formation, scratch wound healing, Matrigel invasion, and protein expression using western blotting were determined. Our findings showed that MBZ and RT combined treatment increased the anticancer effect of RT without additional toxicity. In addition, we noted that cyclin B1, PH2AX, and natural killer (NK) cell-mediated cytotoxicity increased following MBZ + RT treatment compared to unaided RT. Our results suggest that MBZ + RT have an enhanced anticancer effect in TNBC which acquires radiation resistance through blocking cell cycle progression, initiating DNA double-strand breaks, and promoting NK cell-mediated cytotoxicity.

Comprehensive Analysis of Set-Up Gain of 6-Dimensional Cone-Beam CT Correction Method in Radiotherapy for Head and Neck and Brain Tumors.

This study quantitatively analyzed the gain of the six-dimensional (6D) cone-beam CT (CBCT) correction method compared with the conventional set-up method in 60 patients who underwent radiation treatment of head and neck and brain tumors. The correction gain of CBCT was calculated for the translational and rotational motion components separately and in combination to evaluate the individual and overall effects of these motion components. Using a statistical simulation mimicking the actual set-up correction process, the effective gain of periodic CBCT correction during the entire treatment fraction was analyzed by target size and CBCT correction period under two different correction scenarios: translation alone and full 6D corrections. From the analyses performed in this study, the gain of CBCT correction was quantitatively determined for each situation, and the appropriate CBCT correction strategy was suggested based on treatment purpose and target size.

The Pattern of Care for Brain Metastasis from Breast Cancer over the Past 10 Years in Korea: A Multicenter Retrospective Study (KROG 16-12).

PURPOSE: We aimed to investigate manifestations and patterns of care for patients with brain metastasis (BM) from breast cancer (BC) and compared their overall survival (OS) from 2005 through 2014 in Korea. MATERIALS AND METHODS: We retrospectively reviewed 600 BC patients with BM diagnosed between 2005 and 2014. The median follow-up duration was 12.5 months. We categorized the patients into three groups according to the year when BM was initially diagnosed (group I [2005-2008], 98 patients; group II [2009-2011], 200 patients; and group III [2012-2014], 302 patients). RESULTS: Over time, the median age at BM diagnosis increased by 2.2 years (group I, 49.0 years; group II, 48.3 years; and group III, 51.2 years; p=0.008). The percentage of patients with extracranial metastasis was 73.5%, 83.5%, and 86.4% for group I, II, and III, respectively (p=0.011). The time interval between BC and BM was prolonged in patients with stage III primary BC (median, 2.4 to 3 years; p=0.029). As an initial brain-directed treatment, whole-brain radiotherapy alone decreased from 80.0% in 2005 to 41.1% in 2014. Meanwhile, stereotactic radiosurgery or fractionated stereotactic radiotherapy alone increased from 13.3% to 34.7% during the same period (p=0.005). The median OS for group I, II, and III was 15.6, 17.9, and 15.0 months, respectively, with no statistical significance. CONCLUSION: The manifestations of BM from BC and the pattern of care have changed from 2005 to 2014 in Korea. However, the OS has remained relatively unchanged over the 10 years.

Comparison of treatment outcomes of pelvis external radiotherapy with and without vaginal brachytherapy for cervical cancer patients with positive or close vaginal resected margins.

BACKGROUND: We evaluated whether there is a difference in the local recurrence and survival after pelvic external radiotherapy (ERT) with and without boost vaginal brachytherapy (VB) in cervical cancer patients with positive or close vaginal resected margins (RM). METHODS: We retrospectively reviewed FIGO stage IA-IIB cervical cancer patients treated with postoperative ERT between 1997 and 2018. The sixty patients showing close (safety margin < 5 mm) or positive vaginal RM were included. ERT was delivered with median 50.4 Gy in 28 fractions to the pelvis and VB with median 30 Gy in 6 fractions. RESULTS: The median follow-up duration was 46 months. Five out of 30 patients treated with ERT alone experienced vaginal recurrence within 2 years after surgery. The 5-year local control (LC) was 100% in patients receiving ERT + VB compared with 81.3% in patients receiving ERT alone (log rank p = 0.022). The 5-year pelvic control (PC) was 95.8% for patients receiving ERT + VB and 76.8% for ERT alone (p = 0.041). The 5-year overall survival and recurrence-free survival (RFS) were not significantly different between treatment groups. In multivariate analysis, perineural invasion was a significant risk factor for PC (p = 0.024). Parametrial involvement (p = 0.044) and vascular invasion (p = 0.032) were unfavorable prognostic factors for RFS. Late toxicity occurrences were not significant in both groups. CONCLUSION: VB after ERT improved LC and PC in cervical cancer patients with close or positive RM after hysterectomy. The toxicities were not increased after VB was added to ERT.

Sarcopenia using pectoralis muscle area and lymphocyte-to-monocyte ratio (LMR) are independent prognostic factors in patients for nonmetastatic breast cancer.

Sarcopenia is defined as loss of skeletal muscle mass and strength. This can lead to adverse clinical outcomes in patients with advanced cancer. The lymphocyte-to-monocyte ratio (LMR), a converted inflammatory response, is associated with poor prognosis in patients with malignancies. Herein, we examined the prognostic influence of sarcopenia status assessed by pectoralis muscle area (PMA), inflammatory status calculated by LMR, and its association with disease-free survival (DFS) in a cohort of women diagnosed with nonmetastatic breast cancer. A total of 293 patients with nonmetastatic breast cancer who underwent primary mass resection and radiotherapy between January 2011 and December 2017 were enrolled. The cross-sectional area of the muscle (cm2) at PMA was measured using computed tomography before radiation therapy. Baseline monocyte and lymphocyte counts were obtained from the complete blood count to calculate the LMR. Most of the patients (248/293, 84.6%) underwent breast conservation surgery. Lymph node involvement at diagnosis (hazard ratio [HR], 5.08; P < .001), low LMR (HR, 2.79; P = .007), and low PMA (HR, 3.80; P < .001) were independent poor prognostic factors in multivariate analysis. The mean DFS of sarcopenic and nonsarcopenic patients was 89.8 months and 118.8 months, respectively (P < .001). Sarcopenic patients with low LMR showed the worst outcomes, whereas nonsarcopenic patients with high LMR showed the best outcomes. Low PMA and low LMR were independent poor prognostic factors for DFS in patients with nonmetastatic breast cancer.

Novel prognostic classification predicts overall survival of patients receiving salvage whole-brain radiotherapy for recurrent brain metastasis from breast cancer: A recursive partitioning analysis (KROG 16-12).

BACKGROUND: To investigate outcomes of salvage whole-brain radiotherapy (WBRT) for recurrent brain metastases (BM) from breast cancer (BC), to identify prognostic factors of overall survival (OS), and to propose a novel prognostic classification for OS in these patients. MATERIALS AND METHODS: We identified 54 patients who had received salvage WBRT as the second brain-focused treatment for recurrent BM from BC (2000-2014). The median follow-up duration was 4.9 months. A recursive partitioning analysis (RPA) was conducted to develop a model to predict OS at the time of salvage WBRT. RESULTS: The median OS was 6.8 months. OS according to BC-specific graded prognostic assessment (breast-GPA), modified breast-GPA, and updated breast-GPA did not represent our cohort. In the multivariate analysis, a long time before salvage WBRT (≥16 months), control of primary BC or extracranial metastases, systemic treatment after salvage WBRT, and administration of a biologically effective dose for an α/ß of 10 Gy (BED10) of salvage WBRT >37.5 Gy showed superior OS. We proposed three RPA classes based on the control of both primary BC and extracranial metastasis and BED10 of salvage WBRT: class I, class II, and class III. In this model, patients with class I experienced the best OS (34.6 months; class II, 5.0 months; class III, 2.4 months; P < 0.001). CONCLUSIONS: In our RPA classification according to the control of both primary BC and extracranial metastasis and the dose of salvage WBRT, significant differences in OS were observed. The subsequent use of a systemic treatment showed better OS.

Abscopal Effect of Radiotherapy Enhanced with Immune Checkpoint Inhibitors of Triple Negative Breast Cancer in 4T1 Mammary Carcinoma Model.

Local radiotherapy (RT) is important to manage metastatic triple-negative breast cancer (TNBC). Although RT primarily reduces cancer cells locally, this control can be enhanced by triggering the immune system via immunotherapy. RT and immunotherapy may lead to an improved systemic effect, known as the abscopal effect. Here, we analyzed the antitumor effect of combination therapy using RT with an anti-programmed cell death-1 (PD-1) antibody in primary tumors, using poorly immunogenic metastatic mouse mammary carcinoma 4T1 model. Mice were injected subcutaneously into both flanks with 4T1 cells, and treatment was initiated 12 days later. Mice were randomly assigned to three treatment groups: (1) control (no treatment with RT or immune checkpoint inhibitor (ICI)), (2) RT alone, and (3) RT+ICI. The same RT dose was prescribed in both RT-alone and RT+ICI groups as 10Gy/fx in two fractions and delivered to only one of the two tumor burdens injected at both sides of flanks. In the RT+ICI group, 200 µg fixed dose of PD-1 antibody was intraperitoneally administered concurrently with RT. The RT and ICI combination markedly reduced tumor cell growth not only in the irradiated site but also in non-irradiated sites, a typical characteristic of the abscopal effect. This was observed only in radiation-sensitive cancer cells. Lung metastasis development was lower in RT-irradiated groups (RT-only and RT+ICI groups) than in the non-irradiated group, regardless of the radiation sensitivity of tumor cells. However, there was no additive effect of ICI on RT to control lung metastasis, as was already known regarding the abscopal effect. The combination of local RT with anti-PD-1 blockade could be a promising treatment strategy against metastatic TNBC. Further research is required to integrate our results into a clinical setting.

Anticancer Effect of Benzimidazole Derivatives, Especially Mebendazole, on Triple-Negative Breast Cancer (TNBC) and Radiotherapy-Resistant TNBC In Vivo and In Vitro.

In this study, we aimed to evaluate the anticancer effect of benzimidazole derivatives on triple-negative breast cancer (TNBC) and investigate its underlying mechanism of action. Several types of cancer and normal breast cells including MDA-MB-231, radiotherapy-resistant (RT-R) MDA-MB-231, and allograft mice were treated with six benzimidazole derivatives including mebendazole (MBZ). Cells were analyzed for viability, colony formation, scratch wound healing, Matrigel invasion, cell cycle, tubulin polymerization, and protein expression by using Western blotting. In mice, liver and kidney toxicity, changes in body weight and tumor volume, and incidence of lung metastasis were analyzed. Our study showed that MBZ significantly induced DNA damage, cell cycle arrest, and downregulation of cancer stem cell markers CD44 and OCT3/4, and cancer progression-related ESM-1 protein expression in TNBC and RT-R-TNBC cells. In conclusion, MBZ has the potential to be an effective anticancer agent that can overcome treatment resistance in TNBC.

Inter-institutional Variation in Intensity-modulated Radiotherapy for Breast Cancer in Korea (KROG 19-01).

BACKGROUND/AIM: To present the variations in the target delineation and the planning results of intensity-modulated radiation therapy (IMRT) for breast cancers. PATIENTS AND METHODS: We requested the target volumes and organs at risk delineation for two cases of left breast cancers, and evaluated the IMRT plans including the supraclavicular and internal mammary node irradiation. RESULTS: Twenty-one institutions participated in this study. Differences in the planning target volume among institutions reached up to three-times for breast-conserving surgery (BCS) case and five-times for mastectomy case. Mean heart doses ranged from 3.3 to 24.1 Gy for BCS case and from 5.0 to 26.5 Gy for mastectomy case. Ipsilateral lung volumes receiving more than 20 Gy ranged from 4.7 to 57.4% for BCS case and from 16.4 to 55.5% for mastectomy case. CONCLUSION: There were large variations in the target delineation and planning results of IMRT for breast cancers among institutions. Considering the increased use of breast IMRT, more standardized protocols are needed.

Interfractional diaphragmatic position variation according to stomach volume change during respiratory-gated radiotherapy for hepatocellular carcinoma.

PURPOSE: We evaluated the correlation between stomach volume change and interfractional baseline shifts of the diaphragm in image-guided radiotherapy (IGRT) for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty-four patients with HCC underwent ten fractions of IGRT, and a total of 240 cone beam computed tomography (CBCT) and on-board imager (OBI) kV image sets were acquired. These image sets were retrospectively analyzed. Baseline shifts of the diaphragm relative to bone and stomach volume change ratios were evaluated using four-dimensional simulation CT, kV image, and CBCT images. Associations between baseline shifts and patient physiologic factors were investigated. RESULTS: The average baseline shift of the diaphragm in the superior-inferior (SI) direction was 1.5 mm (standard deviation 4.6 mm), which was higher than the shift in other directions (0.7, 2.0 mm and 0.9, 2.6 mm in right-left (RL) and anterior-posterior (AP) directions, respectively). Interfractional baseline shifts of the diaphragm in the SI and AP directions were positively correlated with the stomach volume change ratio (Pearson's r: 0.416 and 0.302, p-value: <0.001 and <0.001, respectively). CONCLUSIONS: The interfractional baseline shifts of the diaphragm in the SI and AP directions correlated well with stomach volume changes. Efforts to maintain a constant stomach volume before the simulation and each treatment, such as fasting, may reduce interfractional baseline shifts of liver tumors.

Effects of Vitamin E on the immune system and tumor growth during radiotherapy.

PURPOSE: The purpose of this study is to evaluate the effects of Vitamin E (VE) on the immune system and tumor growth during radiotherapy (RT) in mice model. METHODS: C57BL/6NCrSlc mice were randomly distributed in four groups (control, VE alone, RT alone, and VE + RT). In the VE and VE + RT groups, VE was administered in the diet at 500 mg/kg. Radiation was delivered at 2 Gy in a single fraction on the whole body or at 6 Gy in three fractions locally in the RT and VE + RT groups. Changes in leukocytes and T lymphocytes were counted and compared between the four groups. To evaluate the effects on tumor growth, Ehrlich carcinoma cells were injected into the thighs of mice, and tumor volumes and growth inhibition rates were compared. RESULTS: The number of leukocytes was increased in the VE group compared with that in the control group. The magnitude of leukocyte recovery after RT was also increased by VE. This change was affected largely by alterations in lymphocytes and monocytes rather than that in granulocytes. Both CD4+ and CD8+ T lymphocytes were positively affected by VE. The tumor growth was inhibited not only by RT but also by VE alone. If RT was delivered with VE, tumor growth was markedly inhibited. CONCLUSION: VE could increase the number of leukocytes, primarily lymphocytes, even after RT was delivered. VE also inhibited the tumor growth in addition to RT. Thus, VE may be a useful radioprotective supplement in radiotherapy without inducing tumor growth.

Cytokine Profiles of Non-Small Cell Lung Cancer Patients Treated with Concurrent Chemoradiotherapy with Regards to Radiation Pneumonitis Severity.

The immunologic aspects of radiation pneumonitis (RP) are unclear. We analyzed variations in cytokine profiles between patients with grade (Gr) 0-1 and Gr ≥ 2 RP. Fifteen patients undergoing concurrent chemoradiotherapy for non-small cell lung cancer were included. Blood samples of 9 patients with Gr 0-1 and 6 with Gr ≥ 2 RP were obtained from the Biobank. Cytokine levels were evaluated using an enzyme linked immunosorbent assay at before radiotherapy (RT) initiation, 1, 3, and 6 weeks post-RT initiation, and 1 month post-RT completion. Concentrations of granulocyte colony-stimulating factor (G-CSF), interleukin (IL)-6, IL-10, IL-13, IL-17, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-ß were analyzed; none were related to the occurrence of Gr ≥ 2 RP at pre-RT initiation. At 3 weeks, relative changes in the G-CSF, IL-6, and IFN-γ levels differed significantly between the groups (p = 0.026, 0.05 and 0.026, respectively). One month post-RT completion, relative changes of IL-17 showed significant differences (p = 0.045); however, relative changes in TNF-α, IL-10, IL-13, and TGF-ß, did not differ significantly. Evaluation of changes in IL-6, G-CSF, and IFN-γ at 3 weeks after RT initiation can identify patients pre-disposed to severe RP. The mechanism of variation in cytokine levels in relation to RP severity warrants further investigation.

New brain metastases after whole-brain radiotherapy of initial brain metastases in breast cancer patients: the significance of molecular subtypes (KROG 16-12).

PURPOSE: To identify the risk factors leading to new brain metastases (BM) following brain-directed treatment for initial BM resulting from breast cancer (BC). METHODS: In this multi-institutional study, 538 BC patients with available follow-up imaging after brain-directed treatment for initial BM were analyzed. Tumor molecular subtypes were classified as follows: hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-, n = 136), HER2-positive (HER2+, n = 253), or triple-negative BC (TNBC, n = 149). RESULTS: In 37.4% of patients, new BM emerged at a median of 10.5 months after brain-directed treatment for initial BM. The 1-year actuarial rate of new BM for HR+/HER2-, HER2+, and TNBC were 51.9%, 44.0%, and 69.6%, respectively (p = 0.008). Initial whole-brain radiotherapy (WBRT) reduced new BM rates (22.5% reduction at 1 year, p < 0.001) according to molecular subtype (HR+/HER2-, 42% reduction at 1 year, p < 0.001; HER2+, 18.5%, p = 0.004; TNBC, 16.9%, p = 0.071). Multivariate analysis revealed an increased risk of new BM for the following factors: shorter intervals between primary BC diagnoses and BM (p = 0.031); TNBC (relative to HR+/HER2-) (p = 0.016); presence of extracranial metastases (p = 0.019); number of BM (>4) (p < 0.001); and BM in both tentorial regions (p = 0.045). Anti-HER2 therapy in HER2+ patients (p = 0.013) and initial use of WBRT (p < 0.001) significantly lowered new BM development. CONCLUSIONS: Tumor molecular subtypes were associated with both rates of new BM development and the effectiveness of initial WBRT. Anti-HER2 therapy in HER2+ patients significantly lowered new BM occurrence.

Synergistic Tumoricidal Effects of Alpha-Lipoic Acid and Radiotherapy on Human Breast Cancer Cells via HMGB1.

PURPOSE: Radiotherapy (RT) is one of main strategies of cancer treatment. However, some cancer cells are resistant to radiation-induced cell death, including apoptosis. Therefore, alternative approaches targeting different anti-tumor mechanisms such as cell senescence are required. This study aimed to investigate the synergistic effect of alpha-lipoic acid (ALA) on radiation-induced cell death and senescence in MDA-MB-231 human breast cancer cells. MATERIALS AND METHODS: The cells were divided into four groups depending on the cell treatment (control, ALA, RT, and ALA+RT). Cells were analyzed for morphology, apoptotic cell death, mitochondrial reactive oxygen species, membrane potential, cellular senescence, and cell cycle. RESULTS: Our data showed that ALA significantly promoted apoptotic cell death when combined with RT, as reflected by Annexin V staining, expression of apoptosis-related factors, mitochondrial damages as well as cell morphological changes and reduction of cell numbers. In addition, ALA significantly enhanced radiation-induced cellular senescence, which was shown by increased HMGB1 expression in the cytosol fraction compared to the control, increased p53 expression compared to the control, activation of p38 as well as nuclear factor кB, and G2/M cell cycle arrest. CONCLUSION: The current study is the first report showing a new mode of action (senescence induction) of ALA beyond apoptotic cell death in MDA-MB-231 cancer cells known to be resistant to RT.

Effectiveness of stereotactic body radiotherapy for portal vein tumor thrombosis in patients with hepatocellular carcinoma and underlying chronic liver disease.

AIM: Stereotactic-body radiotherapy (SBRT) is a treatment option for portal vein tumor thrombosis (PVTT) in patients with hepatocellular carcinoma (HCC). Here, we report on our experience of treating PVTT using SBRT in patients with concomitant underlying chronic liver disease. METHODS: This study included 24 patients. The initial prescription dose was 45 Gy in three fractions in 17 (70.8%) patients, but it was modified in the remaining seven (29.2%) patients, with the dose ranging from 39 to 42 Gy in 3-4 fractions. After SBRT, transarterial chemoembolization (TACE) was performed in 16 (66.7%) patients. RESULTS: Of the 24 patients, 2 (8.3%) showed complete response, while 11 (45.8%) showed partial response. After a median follow-up of 8.4 months (range: 2.6-56.5 months), the 1-year overall survival (OS) and the median survival were 67.5% and 20.8 months, respectively. Both combined SBRT and TACE and grade ≥3 hepatic toxicity affected the 1-year OS (SBRT alone vs SBRT + TACE: 14.6% vs 71.4%, P < .001; presence of hepatic toxicity vs absence: 0% vs 81.1%, P = .002). CONCLUSIONS: Overall, SBRT, especially in combination with TACE, is an effective treatment for patients with HCC and PVTT. An optimal dose schedule must be followed to reduce hepatic toxicity while maintaining tumor response.

Tumor Control and Overall Survival after Stereotactic Body Radiotherapy for Pulmonary Oligometastases from Colorectal Cancer: A Meta-Analysis.

PURPOSE: In pulmonary oligometastases from colorectal cancer (POM-CRC), the primarily recommended local therapy is metastasectomy. Stereotactic body radiotherapy (SBRT) is another local therapy modality that is considered as an alternative option in patients who cannot undergo surgery. The purpose of this meta-analysis is to demonstrate the effects of SBRT on POM-CRC by integrating the relevant studies. MATERIALS AND METHODS: The authors explored MEDLINE, EMBASE, Cochrane Library, Web of Science, and SCOPUS, and selected studies including patients treated with SBRT for POM-CRC and availability of local control (LC) or overall survival (OS) rate. In this meta-analysis, the effect of SBRT was presented in the form of the LC and OS rates for 1, 2, 3, and 5 years after SBRT as pooled estimates, and the frequency of pulmonary toxicity of grade 3 or higher after SBRT (PTG3-SBRT). RESULTS: Fourteen full texts among the searched 4,984 studies were the objects of this meta-analysis. The overall number of POM-CRC patients was 495 as per the integration of 14 studies. The pooled estimate LC rate at 1, 2, 3, and 5 years after SBRT was 81.0%, 71.5%, 56.0%, and 61.8%, and the OS rate was 86.9%, 70.1%, 57.9%, and 43.0%, respectively. The LC and OS rates gradually declined until 3 years after SBRT in a similar pattern. Among the 14 studies, only two studies reported PTG3-SBRT as 2.2% and 10.8%, respectively. CONCLUSION: For POM-CRC, SBRT is an ablative therapy with a benefit on LC and OS rates and less adverse effects on the lung.