Synthesis of Topological Gels by Penetrating Polymerization Using a Molecular Net.

Topological gels possess structures that are cross-linked only via physical constraints; ideally, no attractive intermolecular interactions act between their components, which yields interesting physical properties. However, most reported previous topological gels were synthesized based on supramolecular interlocked structures such as polyrotaxane, for which attractive intermolecular interactions are essential. Here, we synthesize a water-soluble "molecular net" (MN) with a large molecular weight and three-dimensional network structure using poly(ethylene glycol). When a water-soluble monomer (N-isopropylacrylamide) is polymerized in the presence of the MNs, the extending polymer chains penetrates the MNs to form an ideal topological MN gel with no specific attractive interactions between its components. The MN gels show unique physical properties as well a significantly high degree of swelling and high extensibility due to slipping of the physical cross-linking. We postulate this method to yield a new paradigm in gel science with unprecedented physical properties.

Phase I trial of myeloablative conditioning with 3-day total marrow and lymphoid irradiation for leukemia.

This prospective phase I trial aimed to determine the recommended dose of 3-day total marrow and lymphoid irradiation (TMLI) for a myeloablative conditioning regimen by increasing the dose per fraction. The primary end-point of this single-institution dose escalation study was the recommended TMLI dose based on the frequency of dose-limiting toxicity (DLT) ≤100 days posthematopoietic stem cell transplantation (HSCT); a 3 + 3 design was used to evaluate the safety of TMLI. Three dose levels of TMLI (14/16/18 Gy in six fractions over 3 days) were set. The treatment protocol began at 14 Gy. Dose-limiting toxicities were defined as grade 3 or 4 nonhematological toxicities. Nine patients, with a median age of 42 years (range, 35-48), eight with acute lymphoblastic leukemia and one with chronic myeloblastic leukemia, received TMLI followed by unrelated bone marrow transplant. The median follow-up period after HSCT was 575 days (range, 253-1037). Three patients were enrolled for each dose level. No patient showed DLT within 100 days of HSCT. The recommended dose of 3-day TMLI was 18 Gy in six fractions. All patients achieved neutrophil engraftment at a median of 19 days (range, 14-25). One-year overall and disease-free survival rates were 83.3% and 57.1%, respectively. Three patients experienced relapse, and no nonrelapse mortality was documented during the observation period. One patient died due to disease relapse 306 days post-HSCT. The recommended dose of 3-day TMLI was 18 Gy in six fractions. The efficacy evaluation of this regimen is currently being planned in a phase II study.

An Area-Efficient up/down Double-Sampling Circuit for a LOFIC CMOS Image Sensor.

A lateral overflow integration capacitor (LOFIC) complementary metal oxide semiconductor (CMOS) image sensor can realize high-dynamic-range (HDR) imaging with combination of a low-conversion-gain (LCG) signal for large maximum signal electrons and a high-conversion-gain (HCG) signal for electron-referred noise floor. However, LOFIC-CMOS image sensor requires a two-channel read-out chain for LCG and HCG signals whose polarities are inverted. In order to provide an area-efficient LOFIC-CMOS image sensor, a one-channel read-out chain that can process both HCG and LCG signals is presented in this paper. An up/down double-sampling circuit composed of an inverting amplifier for HCG signals and a non-inverting attenuator for LCG signals can reduce the area of the read-out chain by half compared to the conventional two-channel read-out chain. A test chip is fabricated in a 0.18 µm CMOS process with a metal-insulator-metal (MIM) capacitor, achieving a readout noise of 130 µVrms for the HCG signal and 1.19 V for the LCG input window. The performance is equivalent to 103 dB of the dynamic range with our previous LOFIC pixel in which HCG and LCG conversion gains are, respectively, 160 µV/e- and 10 µV/e-.

Fracture risk following stereotactic body radiotherapy for long bone metastases.

BACKGROUND: Stereotactic body radiotherapy is a new treatment modality for long bone metastasis and has not been discussed in literature. We aimed to clarify stereotactic body radiotherapy outcomes for long bone metastases. METHODS: Data of patients receiving stereotactic body radiotherapy for long bone metastases (July 2016-November 2020) were retrospectively reviewed. The prescribed dose was 30 or 35 Gy in five fractions. The endpoints were local failure and adverse effects. Local failure was defined as radiological tumor growth within the irradiation field. Adverse effects were evaluated according to the National Cancer Institute Common Terminology Criteria for Adverse Events, version 5. RESULTS: Nineteen osseous lesions in 17 patients were assessed. The target lesions included 13 femoral, 4 humeral and 2 radial lesions. The median follow-up duration was 14 (range, 3-62) months. The 12- and 18-month local failure rates were 0 and 11%, respectively. Following 2 and 46 months of stereotactic body radiotherapy, two lesions (11%) resulted in painful femoral fractures (grade 3). Both patients underwent bipolar hip arthroplasty and could walk normally after surgery. In the late phase, one patient developed radiculopathy (almost complete paralysis of grasp) and another developed grade 2 limb edema. Other grade 2 or more severe acute and late toxicities were not observed during the follow-up period. CONCLUSIONS: Stereotactic body radiotherapy for long bone metastases achieved excellent local control and caused two femoral fractures. We argue that stereotactic body radiotherapy for curative intent should not be contraindicated in long bone oligometastasis because fractures do not directly contribute to life expectancy.

Risk of radiculopathy caused by second course of spine stereotactic body radiotherapy.

OBJECTIVE: Stereotactic body radiotherapy is used to treat spinal metastases; however, 10% of patients experience local failure. We aimed to clarify the outcomes of the second course of stereotactic body radiotherapy for spinal metastases with a uniform fractionation schedule at our institution. METHODS: Data of patients treated with a second salvage stereotactic body radiotherapy course at the same spinal level or adjacent level from July 2018 to December 2020 were retrospectively reviewed. The initial prescribed dose was 24 Gy in two fractions, and the second dose 30 or 35 Gy in five fractions. The spinal cord dose constraint at the second course was 15.5 Gy at the maximum point dose. The endpoints were local failure and adverse effects. Local failure was defined as tumor progression using imaging. RESULTS: We assessed 19 lesions in 17 patients, with radioresistant lesions in 14 (74%) cases, the second stereotactic body radiotherapy to the same/adjacent spinal level in 13/6 cases, the median interval between stereotactic body radiotherapy of 23 (range, 6-52) months, and lesions compressing the cord in 5 (26%) cases. The median follow-up period was 19 months. The 12- and 18-month local failure rates were 0% and 8%, respectively. Radiation-induced myelopathy, radiculopathy and vertebral compression fractures were observed in 0 (0%), 4 (21%) and 2 (11%) lesions, respectively. Three patients with radiculopathy experienced almost complete upper or lower limb paralysis. CONCLUSIONS: The second course of salvage stereotactic body radiotherapy for spinal metastases achieved good local control with a reduced risk of myelopathy. However, a high occurrence rate of radiation-induced radiculopathy has been confirmed.

Efficacy and toxicity of re-irradiation spine stereotactic body radiotherapy with respect to irradiation dose history.

OBJECTIVE: We aimed to clarify the outcomes of re-irradiation stereotactic body radiotherapy for spinal metastases with a uniform dose fractionation schedule at our institution. METHODS: Data of patients treated with re-irradiation stereotactic body radiotherapy for spinal metastases (September 2013-March 2020) were retrospectively reviewed. The prescribed dose was 24 Gy in two fractions. The spinal cord dose constraint and dose for previously irradiated cases ≥50 Gy in 25 fractions were 12.2 Gy (maximum dose) and 11 Gy, respectively. The endpoints were pain control, local failure and adverse effects. Pain status was measured on a scale of 0-10 using the patients' self-reports and pain response was defined using international consensus criteria. Local failure was defined as tumor progression on imaging evaluations. RESULTS: We assessed 133 lesions in 123 patients, where 70 (52.6%) had three or more spinal levels treated, 58 (43.6%) had previous irradiation doses of 40 Gy or more and 53 (39.8%) had the targets compressing the cord. The median follow-up was 12 months and the 3-, 6- and 12-month pain response rate was 75, 64 and 59%, respectively. The 1-year local failure rate was 25.8%. Previous irradiation dose was not correlated with local failure rate (P = 0.13). Radiation-induced myelopathy, radiculopathy and vertebral compression fractures were observed in 4 (3.0%), 2 (1.5%) and 17 (13.8%) lesions, respectively. A trend towards an association between any toxicity and previous irradiation dose was not observed. CONCLUSIONS: Re-irradiation spine stereotactic body radiotherapy achieved good local control and pain control, with reduced risk of radiation myelopathy.

The protective effect of tight-fitting powered air-purifying respirators during chest compressions.

BACKGROUND: Airborne personal protective equipment is required for healthcare workers when performing aerosol-generating procedures on patients with infectious diseases. Chest compressions, one of the main components of cardiopulmonary resuscitation, require intense and dynamic movements of the upper body. We aimed to investigate the protective effect of tight-fitting powered air-purifying respirators (PAPRs) during chest compressions. METHODS: This single-center simulation study was performed from February 2021 to March 2021. The simulated workplace protection factor (SWPF) is the concentration ratio of ambient particles and particles inside the PAPR mask; this value indicates the level of protection provided by a respirator when subjected to a simulated work environment. Participants performed continuous chest compressions three times for 2 min each time, with a 4-min break between each session. We measured the SWPF of the tight-fitting PAPR during chest compression in real-time mode. The primary outcome was the ratio of any failure of protection (SWPF <500) during the chest compression sessions. RESULTS: Fifty-four participants completed the simulation. Overall, 78% (n = 42) of the participants failed (the measured SWPF value was less than 500) at least one of the three sessions of chest compressions. The median value and interquartile range of the SWPF was 4304 (685-16,191). There were no reports of slipping down of the respirator or mechanical failure during chest compressions. CONCLUSIONS: Although the median SWPF value was high during chest compressions, the tight-fitting PAPR did not provide adequate protection.

Sputum Gram Stain for Bacterial Pathogen Diagnosis in Community-acquired Pneumonia: A Systematic Review and Bayesian Meta-analysis of Diagnostic Accuracy and Yield.

BACKGROUND: The clinical role of sputum Gram stain (SGS) in community-acquired pneumonia (CAP) diagnosis remains controversial. A 1996 meta-analysis of the diagnostic accuracy of SGS reported heterogeneous results. To update the available evidence, we performed a systematic review and a Bayesian standard and latent-class model meta-analysis. METHODS: We searched Medline, Embase, and Cochrane Central by 23 August 2018 to identify studies reporting on the diagnostic accuracy, yield (percentage of patients with any pathogen[s] correctly identified by SGS), and clinical outcomes of SGS in adult patients with CAP. Two reviewers extracted the data. We quantitatively synthesized the diagnostic accuracy and yield, and descriptively analyzed other outcomes. RESULTS: Twenty-four studies with 4533 patients were included. The methodological and reporting quality of the included studies was limited. When good-quality sputum specimens were selected, SGS had a summary sensitivity of 0.69 (95% credible interval [CrI], .56-.80) and specificity of 0.91 (CrI, .83-.96) for detecting Streptococcus pneumoniae, and a sensitivity of 0.76 (CrI, .60-.87) and specificity of 0.97 (CrI, .91-.99) for Haemophilus influenzae. Adjusted analyses accounting for imperfect reference standards provided higher-specificity estimates than the unadjusted analyses. Bacterial pathogens were identified in 73% (CrI, 26%-96%) of good-quality specimens, and 36% (CrI, 22%-53%) of all specimens regardless of quality. Evidence on other bacteria was sparse. CONCLUSIONS: SGS was highly specific to diagnose S. pneumoniae and H. influenzae infections in patients with CAP. With good-quality specimens, SGS can provide clinically actionable information for pathogen-directed antibiotic therapies.

Radiation therapy and the risk of herpes zoster in patients with cancer.

BACKGROUND: The role and impact of radiation therapy (RT) on the development of herpes zoster (HZ) has not been well studied. The objective of this study was to investigate the association between RT and HZ. METHODS: A propensity score-matched, retrospective cohort study was conducted using institutional cancer registry data and medical records from 2011 to 2015. The risk of developing HZ in the RT and non-RT groups was compared using a Cox proportional hazards model. Associations also were explored between the RT field and the anatomic location of HZ in patients who developed HZ after RT. The expected number of HZ events within the radiation field was calculated according to the RT received by each patient; then, this number was compared with the observed number of in-field events. RESULTS: Of 17,655 patients, propensity score matching yielded 4350 pairs; of these, 3891 pairs were eligible for comparison. The cumulative incidence of HZ in the RT group (vs the non-RT group) during the first 5 years after the index date was 2.1% (vs 0.7%) at 1 year, 3.0% (vs 1.0%) at 2 years, 3.4% (vs 1.3%) at 3 years, 4.1% vs 1.7% at 4 years, and 4.4% vs 1.8% at 5 years. The RT group showed a significantly higher risk of HZ than the non-RT group (hazard ratio, 2.59, 95% CI, 1.84-3.66). In the 120 patients who developed HZ after RT, HZ events were observed significantly more frequently within the RT field than expected (74 vs 43.8 events; P < .001). CONCLUSIONS: Patients with cancer who received RT showed a significantly higher risk of HZ, which was commonly observed within the radiation field.

Stereotactic body radiotherapy for bone metastases in patients with colorectal cancer.

OBJECTIVE: To clarify the clinical outcomes of stereotactic body radiotherapy for colorectal cancer-derived bone metastases and identify factors predicting treatment failure. METHODS: Patients treated with stereotactic body radiotherapy for bone metastases from colorectal cancer between September 2013 and June 2019 were retrospectively reviewed. The prescribed dose for spine and non-spine bone metastases was 24 Gy in two fractions and 35 Gy in five fractions, respectively. The end point was local failure, which was defined as tumour progression on imaging evaluations. In addition, various treatment- and tumour-specific factors were evaluated to determine predictors of local failure. RESULTS: This study included 43 lesions in 38 patients, with solitary bone metastases in 18 lesions (42%), re-irradiation stereotactic body radiotherapy in 28 lesions (65%) and postoperative stereotactic body radiotherapy due to spinal cord compression in 10 lesions (23%). The median follow-up after stereotactic body radiotherapy was 12 (range, 2-60) months. The 1-year LF rate was 44%. In the univariate analysis, sacral metastases (P = 0.02) were found to be significantly correlated with LF, and multiple-course systemic therapy before stereotactic body radiotherapy (P= 0.06) and large target volume (P = 0.07) showed a trend towards an association with LF. However, these factors were not independent predictors of LF in the multivariate analysis. CONCLUSION: More than 40% of the lesions treated with stereotactic body radiotherapy for bone metastases from colorectal cancer showed LF within 1 year. No poor prognostic factors could be identified statistically. The poor outcomes in all groups indicate that the treatment intensity of the stereotactic body radiotherapy was insufficient to control colorectal cancer bone metastases.

Appropriate endpoints for stereotactic body radiotherapy for bone metastasis: Classification into five treatment groups.

Treatment of bone metastasis using stereotactic body radiotherapy (SBRT) is being widely used in clinical practice. The reported clinical advantages of SBRT include high pain and local control rates, high response rates against bone metastasis from radio-resistant tumors, and safe re-irradiations. Although most reports in the literature use local control as the primary treatment endpoint, this endpoint is not appropriate because local control does not relate directly to patient benefit. Herein, we proposed five pathophysiology-based patient groups, as well as appropriate endpoints for each group.

Determining the recommended dose of stereotactic body radiotherapy boost in patients with cervical cancer who are unsuitable for intracavitary brachytherapy: a phase I dose-escalation study.

OBJECTIVE: Some patients are ineligible for intracavitary brachytherapy (ICBT) for locally advanced cervical cancer. Stereotactic body radiotherapy (SBRT) could be a good treatment option for such patients. This phase I clinical trial aimed to determine the recommended SBRT boost dose for ICBT-ineligible cervical cancer patients. METHODS: Patients with untreated uterine cervical cancer (clinical stages IB1-IIIB) who were ineligible for ICBT were enrolled. Radiotherapy consisted of whole-pelvis radiotherapy (45 Gy in 25 fractions) followed by SBRT. Three dose levels of SBRT (19.5/21/22.5 Gy in three fractions) were set; the treatment protocol began at 21 Gy (level 2). The 'rolling-six' design study was used to establish the recommended dose of SBRT. Each dose level covered three or six patients. The primary endpoint included dose-limiting toxicity (DLT), defined as the occurrence of grade 3 (or worse) non-hematologic adverse effects within 6 months after SBRT. RESULTS: The median follow-up after registration was 17 (range, 8-32) months. Three patients were enrolled in study level 2 (SBRT of 21 Gy); none of the patients exhibited DLT within 6 months after treatment completion. In study level 3 (SBRT of 22.5 Gy), three patients did not exhibit DLT. Although all six patients achieved locoregional control during follow-up, one patient treated with level 2 SBRT experienced distant metastases 14 months after registration. CONCLUSIONS: The recommended dose of SBRT boost was 22.5 Gy in three fractions. We plan to conduct a phase II multi-center clinical trial using the methodology obtained from the current study.

Re-irradiation for painful bone metastases using stereotactic body radiotherapy.

PURPOSE: Stereotactic body radiotherapy (SBRT) is expected to achieve safe and effective re-irradiation for painful bone metastases. This study aimed to clarify the efficacy of re-irradiation using SBRT for painful bone metastases. METHODS: Prospective database at our institution for the period between September 2013 and December 2017 were retrospectively reviewed for patients with: (1) painful bone metastases; (2) history of radiotherapy to the metastasis; and (3) SBRT performed as re-irradiation. Pain response, pain failure-free duration, analgesics medications, and adverse events were evaluated. Pain was evaluated using the Numerical Rating Pain Score, and pain response was evaluated based on International Consensus Pain Response Endpoints. Best response during follow-up was noted. Patients with complete or partial response were defined as showing pain response, and patients with pain progression were defined as showing pain failure. Adverse events were evaluated based on the RTOG/EORTC Late Radiation Morbidity Scoring Schema. RESULTS: Sixty-six patients selected from our database showed: median age, 65 years (range, 33-82 years); ECOG performance status, 0-1/2/3/4, 51/10/3/2; lesion histopathology, rectal/lung/renal/thyroid/other cancer, 13/11/9/5/28; median previous irradiated dose, 30 Gy (range, 8-70.4 Gy); median interval from latest irradiation, 21 months (range, 4-192 months); prescribed dose for SBRT, 24 Gy in 2 fractions/30 Gy in 5 fractions/35 Gy in 5 fractions, 51/13/2. Median follow-up after SBRT was 10 months (range, 1-37 months). Fifty-seven patients achieved pain response (86%). The 1-year pain failure-free rate was 55%. Median pain failure-free duration was 13 months (range, 1-24 months). Grade 4 adverse events were observed in six patients (vertebral compression fracture, n = 5; radiation myelopathy, n = 1). No other toxicities of Grade 3 or greater were encountered. CONCLUSIONS: Re-irradiation SBRT has potential to achieve good response and long-term pain control for painful bone metastases. Prospective analysis is necessary to confirm the safety and efficacy of SBRT as re-irradiation.

Effect of azithromycin on enhancement of methane production from waste activated sludge.

In the methane production from waste activated sludge (WAS), complex bacterial interactions in WAS have been known as a major contribution to methane production. Therefore, the influence of bacterial community changes toward methane production from WAS was investigated by an application of antibiotics as a simple means for it. In this study, azithromycin (Azm) as an antibiotic was mainly used to observe the effect on microbial changes that influence methane production from WAS. The results showed that at the end of fermentation, Azm enhanced methane production about twofold compared to control. Azm fostered the growth of acid-producing bacterial communities, which synthesized more precursors for methane formation. DGGE result showed that the hydrolysis as well as acetogenesis stage was improved by the dominant of B1, B2 and B3 strains, which are Clostridium species. In the presence of Azm, the total population of archaeal group was increased, resulting in higher methane productivity achievement.

Ion Tracks and Nanohillocks Created in Natural Zirconia Irradiated with Swift Heavy Ions.

Natural monoclinic zirconia (baddeleyite) was irradiated with 340 MeV Au ions, and the irradiation-induced nanostructures (i.e., ion tracks and nanohillocks) were observed using transmission electron microscopy. The diameter of the nanohillocks was approximately 10 nm, which was similar to the maximum molten region size calculated using the analytical thermal spike model. Ion tracks were imaged as strained regions that maintained their crystalline structure. The cross-sections of most of the ion tracks were imaged as rectangular contrasts as large as 10 nm. These results strongly indicated that the molten region was recrystallized anisotropically, reflecting the lattice structure. Furthermore, low-density track cores were formed in the center of the ion tracks. The formation of low-density track cores can be attributed to the ejection of molten matter toward the surface. A comparison of the ion tracks in the synthetic zirconia nanoparticles and those in larger natural zirconia samples showed that the interface between the strained track contrast and the matrix was less clear in the former than in the latter. These findings suggest that the recrystallization process was affected by the size of the irradiated samples.

Phase II Clinical Trial of Second Course of Stereotactic Body Radiotherapy for Spinal Metastases.

PURPOSE: The optimal method for the second course of stereotactic body radiotherapy (SBRT) for spinal metastases remains poorly established. This single-center, single-arm, phase II trial was conducted to propose a safe and effective salvage spine SBRT. METHODS: The patients initially treated with SBRT for spine-targeted protocol treatment, or for areas adjacent to the spine, were enrolled. The second SBRT dose was 30 Gy delivered in five fractions; the spinal cord dose constraint was 15.5 Gy at the maximum point dose. The brachial or lumbosacral plexuses were dose-constrained to <30 Gy if the boundary between the nerves and tumors was detected. The primary endpoint was dose-limiting toxicity (DLT) (grade ≥ 3 severe radiation-related toxicity) within a year after the second SBRT. RESULTS: The second SBRT was administered to the same spinal level in 12 patients and to an adjacent spinal level in 8 patients. SBRT2 was performed for 14 painful lesions, 10 MESCC, and 6 oligometastases, with some lesions having multiple indications. The median interval between SBRT sessions was 21 months (range: 6-51 months). The median follow-up duration was 14 months. No radiation myelopathy or local failure was reported during the follow-up period. DLT was confirmed in two patients (10%) within a year, both of whom developed grade 3 lumbosacral plexopathy. These two patients received SBRT twice to the S1-2 and S1-5 vertebrae, respectively, and both experienced paralysis of the tibialis anterior muscle (L5 level). Grade 3 late adverse effects (including lumbosacral plexopathy and vertebral compression fracture) were observed in 25% of the patients throughout the entire follow-up period. CONCLUSIONS: The second spine SBRT achieved good local control without causing myelopathy. However, one-quarter of the patients experienced grade 3 late adverse effects, suggesting that the treatment protocol carries a risk of toxicity.

Phase I/II study of stereotactic body radiotherapy boost in patients with cervical cancer ineligible for intracavitary brachytherapy.

PURPOSE: Stereotactic body radiotherapy (SBRT) boost is a promising treatment for cervical cancer patients who are ineligible for intracavitary brachytherapy (ICBT). The aim of this multicenter, single-arm, phase I/II study was to prospectively evaluate the efficacy and toxicity of SBRT boost. MATERIALS AND METHODS: ICBT-ineligible patients with untreated cervical cancer were enrolled. Patients underwent whole-pelvic radiotherapy (45 Gy in 25 fractions) with SBRT boost to the primary lesion. In the phase I dose-escalation cohort (3 + 3 design), patients were treated with SBRT boost of 21 or 22.5 Gy in three fractions. Although dose-limiting toxicity was not confirmed, a dose of 21 Gy was selected for the phase II cohort because it was difficult to reproduce the pelvic organs position in two patients during the phase I trial. The primary endpoint was 2-year progression-free survival. RESULTS: Twenty-one patients (phase I, n = 3; phase II, n = 18) were enrolled between April 2016 and October 2020; 17 (81%) had clinical stage III-IV (with para-aortic lymph node metastases) disease. The median (range) follow-up was 40 (10-84) months. The initial response was complete response in 20 patients and partial response in one patient. The 2-year locoregional control, progression-free survival, and overall survival rates were 84%, 67%, and 81%, respectively. Grade ≥ 3 toxicity was confirmed in one patient each in the acute (diarrhea) and late (urinary tract obstruction) phases. CONCLUSION: These findings suggested that a SBRT boost is more effective than the conventional EBRT boost and can be an important treatment option for ICBT-ineligible patients with cervical cancer. STUDY REGISTRATION: This study was registered at the University Hospital Medical Information Network Clinical Trials Registry (UMIN000036845).

Incidence and Prognostic Factors of Painful Vertebral Compression Fracture Caused by Spine Stereotactic Body Radiotherapy.

Most studies of vertebral compression fractures (VCF) caused by stereotactic body radiotherapy (SBRT) do not discuss the symptoms of this complication. In this paper, we aimed to determine the rate and prognostic factors of painful VCF caused by SBRT for spinal metastases. Spinal segments with VCF in patients treated with spine SBRT between 2013 and 2021 were retrospectively reviewed. The primary endpoint was the rate of painful VCF (grades 2-3). Patient demographic and clinical characteristics were evaluated as prognosticators. In total, 779 spinal segments in 391 patients were analyzed. The median follow-up after SBRT was 18 (range: 1-107) months. Sixty iatrogenic VCFs (7.7%) were identified. The rate of painful VCF was 2.4% (19/779). Eight (1.0%) VCFs required surgery for internal fixation or spinal canal decompression. The painful VCF rate was significantly higher in patients with no posterolateral tumor involvement than in those with bilateral or unilateral involvement (50% vs. 23%; p = 0.042); it was also higher in patients with spine without fixation than in those with fixation (44% vs. 0%; p < 0.001). Painful VCFs were confirmed in only 2.4% of all the irradiated spinal segments. The absence of posterolateral tumor involvement and no fixation was significantly associated with painful VCF.

Recent Postoperative Radiotherapy for Left-sided Breast Cancer Does Not Increase Mortality of Heart Disease in Asians or Pacific Islanders: SEER Database Analysis.

BACKGROUND/AIM: The purpose of this study was to evaluate the impact of recent radiotherapy on mortality from heart disease in Asians or Pacific islanders with breast cancer using the Surveillance, Epidemiology, and End Results (SEER) database. PATIENTS AND METHODS: Asians or Pacific islanders with stage 0 or I (AJCC 6th) breast cancer between 2000 and 2015 were analyzed. The impact of radiotherapy for mortality from heart disease after treatment was evaluated by comparing patients who received radiotherapy for left-sided breast cancer, patients who received radiotherapy for right-sided breast cancer and patients who did not receive radiotherapy. RESULTS: In 25,684 Asians or Pacific islanders, the incidence of cardiac death was higher in patients who did not receive radiotherapy than in patients who received radiotherapy. Among patients who received external beam irradiation, the incidence of cardiac death was 2.00% for patients with left-sided breast cancer and 1.69% for patients with right-sided breast cancer, with no significant difference (chi-square test, p=0.427). In the period from 2000 to 2008, there was no significant difference between the cumulative heart-related death rates in patients who received radiotherapy and in patients who did not receive radiotherapy (Tarone-Ware test, p=0.406); however, in 2009-2015, the cumulative heart-related death rate in patients who did not receive radiotherapy was significantly higher than that in patients who received radiotherapy (log-rank test, p<0.001). CONCLUSION: Heart-related death after treatment for breast cancer is relatively rare in Asians or Pacific islanders. Since at least 2000, the cardiac impact of postoperative radiotherapy has not been significant.