Minimal short-term decline in functional performance and quality of life predicts better long-term outcomes for both in older Taiwanese adults after hip fracture surgery: a prospective study.

BACKGROUND: Hip fracture can lead to long-term loss of mobility and self-care ability in older adults. Despite initial decreases in functional performance after hip fracture surgery, patients tend to gradually recover. However, recovery can vary, with some regaining their abilities quickly while others becoming functionally dependent. In this study, we investigated whether the level of short-term postoperative decline in activity of daily living (ADL) performance and quality of life (QoL) can predict the 1-year outcomes for both following hip fracture surgery in older Taiwanese adults. METHODS: This prospective cohort study included 427 older adults (≥ 60 years) who underwent hip fracture surgery at a single tertiary medical center in Taiwan between November 2017 and March 2021. We collected pre-fracture data, including the patients' demographics, Charlson comorbidity index (CCI) scores, and responses to a questionnaire (Short Portable Mental State Questionnaire [SPMSQ]) for dementia screening. Moreover, their scores on the EuroQol-5D questionnaire (for evaluating QoL) and the Barthel Index (for assessing ADL performance) were collected at pre-fracture status and at 3- and 12-months following surgery. Changes in ADL and QoL three months post-surgery compared to pre-fracture status were evaluated, and the associations of these parameters (and other potential factors) with 1-year outcomes for ADL and QoL were investigated. RESULTS: We analyzed the data of 318 patients with hip fracture and complete follow-up data regarding ADL performance and QoL at 3- and 12-months post-surgery. After adjusting for covariates, multivariate linear regression revealed that changes in ADL and QoL at 3 months post-surgery from pre-fracture status were positively and significantly associated with 1-year outcomes for both (p < .001 for both). Furthermore, pre-fracture CCI and SPMSQ scores were independent predictive factors associated with 1-year ADL outcomes (p = .042 and < .001, respectively). CONCLUSIONS: Patients who exhibit a smaller decline in functional performance and quality of life three months after hip fracture surgery from pre-fracture status are likely to have improved long-term ADL and QoL. TRIAL REGISTRATION: TMU-JIRB N201709053.

Associations of the Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio with Osteoporosis: A Meta-Analysis.

Osteoporosis is characterized by low bone mass and increased bone fragility. Numerous studies have suggested that inflammation contributes to its pathogenesis. The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are simple, noninvasive biomarkers that can reflect the inflammation status on human body. However, evidence on their associations with osteoporosis remains scant. The PubMed, Embase, and Cochrane Library databases were searched for relevant studies from their inception to April 2022. Observational studies providing complete NLR or PLR data in both the osteoporosis and normal bone mineral density (BMD) groups were included. Studies involving individuals at risk of secondary osteoporosis or restricted to a certain disease population were excluded. The main outcome was the associations of NLR and PLR with osteoporosis. Between-group differences were measured using mean differences (MDs) and 95% confidence intervals (CIs). In our analysis, both NLR and PLR were significantly higher in the osteoporosis group (MD = 0.494, 95% CI: 0.339−0.649, p < 0.0001; MD = 23.33, 95% CI: 4.809−41.850, p = 0.014, respectively) than in the normal BMD group. NLR was significantly higher in postmenopausal women with osteoporosis (MD = 0.432, 95% CI: 0.309−0.544, p < 0.0001). Our findings suggest the associations of NLR and PLR with osteoporosis. NLR and PLR constitute potential targets in osteoporosis screening.

Inverse relation of body weight with short-term and long-term mortality following hip fracture surgery: a meta-analysis.

BACKGROUND: The obesity paradox, which suggests that high body weight is positively associated with survival in some diseases, has not been proven in patients with hip fracture. In this study, meta-analysis of previous studies on the impacts of body weight on postoperative mortality following hip fracture surgery in older adults was conducted. METHODS: PubMed, Embase, and Cochrane library were searched for studies investigating the correlation between mortality after hip fracture surgery and body weight. The search main items included: ("Body mass index" OR "BMI" or "body weight") and ("hip fracture" or "hip fractures"). Studies contained data on short-term (≤ 30-day) and long-term (≥ 1 year) mortality after hip fracture and its association with distinct body weight or BMI groups were reported as full-text articles were included in this meta-analysis. RESULTS: Eleven separate studies were included. The definitions of underweight and obesity differed among the included studies, but the majority of the enrolled studies used the average body weight definition of a BMI of 18.5 to 24.9 kg/m2; underweight referred to a BMI of < 18.5 kg/m2; and obesity pertained to a BMI of > 30 kg/m2. Based on the generalized definitions of body-weight groups from the enrolled studies, the group with obesity had lower long-term (odds ratio [OR]: 0.63, 95% CI: 0.50-0.79, P < 0.00001) and short-term (OR: 0.63, 95% CI: 0.58-0.68, P ≤ 0.00001) mortality rates after hip fracture surgery when compared with patients with average-weight group. However, compared with the average-weight group, the underweight group had higher long-term (OR: 1.51, 95% CI: 1.15-1.98, P=0.003) and short-term (OR: 1.49, 95% CI: 1.29-1.72, P<0.00001) mortality rates after hip fracture surgery. CONCLUSIONS: Current evidence demonstrates an inverse relation of body weight with long-term and short-term mortality after hip fracture surgery in older adults.

Prognostic and radiographic correlates of a prospectively collected molecularly profiled cohort of IDH1/2-wildtype astrocytomas.

BACKGROUND: In the molecular era, the relevance of tumor grade for prognostication of IDH1/2-wildtype (WT) gliomas has been debated. It has been suggested that histologic grade II and III astrocytomas with molecular features of glioblastoma, IDH1/2-WT have a similar prognosis to glioblastoma and should be considered for the same clinical trials. METHODS: We integrated prospective clinical sequencing from 564 patients with IDH1/2-WT gliomas (26 grade II, 71 grade III and 467 grade IV) with clinical and radiographic data to assess associations between molecular features, grade and outcome. RESULTS: Compared to histologic grade IV IDH1/2-WT astrocytomas, histologic grade II astrocytomas harbor fewer chromosome 7/10 alterations (P = 0.04), EGFR amplifications (P = 0.022) and alterations in cell-cycle effectors (P = 1.9e-11), but a similar frequency of TERT promoter mutations. In contrast, there is no difference in the frequency of these canonical molecular features in histologic grade III vs. IV IDH1/2-WT disease. Progression-free (PFS) and overall survival (OS) for histologic grade II tumors were significantly longer than grade III tumors (P = 0.02 and P = 0.008, respectively), whereas there was no difference in PFS and OS for histologic grade III compared to grade IV tumors. Median PFS for histologic grade II, III and IV tumors was 19, 11 and 9 months, respectively. Median OS for the same tumors was 44, 23 and 23 months, respectively. In histologic grade II and III IDH1/2 WT tumors, gliomatosis is associated with the absence of cell-cycle alterations (P = 0.008) and enriched in grade II features (P = 0.1) and alterations in the PI3K-AKT pathway (P = 0.09). CONCLUSIONS: Grade II histology has genotypic and phenotypic associations with prognostic implications in IDH1/2-WT astrocytomas.

Increased age and proton pump inhibitors are associated with severe Clostridium difficile infections in children.

BACKGROUND: Clostridium difficile infection (CDI) is increasing in children. We aimed to compare the clinical characteristics between CDI and colonization and to identify the risk factors for severe diseases of CDI in children. METHOD: We retrospectively reviewed 124 children (1-18 years old) from 2011 to 2018. CDI was defined as diarrhea (≥3 loose stool in the past 24 h) with confirmed toxigenic strain. Colonization was defined as presence of C. difficile without clinical symptoms. Severe diseases included ileus, acute kidney injury, gastrointestinal bleeding or mortality. Patients younger than 1 year old and coinfections with other enteric pathogens were excluded. RESULTS: Among 124 patients with C. difficile identified, 49 of them fulfilled CDI definition and 75 had C. difficile colonization. Children with CDI were more likely to present with watery (74% vs. 1%, p < 0.01) and mucoid stool (25% vs. 7%, p < 0.01) and occult blood in stool (67% vs. 33%, p < 0.01) than children with colonization. In CDI cases, elevated age-adjusted creatinine (18% vs. 0%, p = 0.03) and hyponatremia (134 mEq/L vs. 137 mEq/L, p = 0.04) were found. Also, they had more complicated diseases (27% vs. 0%, p < 0.01). On multivariate analysis, age older than 4 years (adjusted odds ratio: 5.83; 95% confidence interval: 1.05-32.27) and proton pump inhibitor use (PPI) (adjusted odds ratio: 7.25; 95% confidence interval: 1.07-49.07) were the independent factors for severe diseases. CONCLUSIONS: Watery diarrhea, mucoid stool and occult blood in stool could differentiate CDI from colonization. Patients with increased age and previous PPI use were the independent risk factors for severe diseases in children.

Case report: painful exanthems caused by enterovirus D68 in an adolescent.

RATIONALE: Unlike other enteroviruses which can cause herpangina or hand-foot-and-mouth disease, enterovirus D68 (EV-D68) has usually been linked to respiratory and neurological problems in young children. Skin manifestations had rarely been described in current literatures. PATIENT CONCERNS: We report a 17-year-old girl with fever and painful skin rash over legs and soles for 9 days. Pitting edema was also noted below the knees. There was no respiratory tract or neurological symptoms in this patient. DIAGNOSES: EV-D68 was detected from a throat swab by RT-PCR and confirmed to be subclade B3 by sequencing. INTERVENTIONS: Supportive management. OUTCOMES: The patient was afebrile after 9 days and got full recovery on the 23rd day at outpatient follow-up. LESSONS: To the best of our knowledge, this is the first report of EV-D68 infection with skin manifestations, clinical images, and detailed clinical course. Our findings in this particular case extend the understanding of the disease spectrum.

Adenovirus replication and host innate response in primary human airway epithelial cells.

BACKGROUND: Adenovirus infections are very common in children and sometimes fatal. Immune responses and hypercytokinemia are related to disease severity in patients with adenovirus infection. Understanding of viral replication and immune responses could help elucidate the immunopathogenesis of severe adenovirus infections. METHODS: Polarized human airway epithelial cells (hAECs) were set up to mimic human airway, and we conducted high (1 the multiplicity of infection, MOI) and low dosage (0.5 MOI) of wild-type adenovirus serotype 3 infection in hAECs from both apical (AP) and basolateral (BL) compartments, compared the viral replication kinetics and measured 25 cytokine and 9 chemokine levels by multiplex immunoassay to evaluate the host immune response. RESULTS: Virus titer was the highest in the apical compartment in low dose apical infection. BL infection showed a relative steady viral titer in different doses and infection sites. Responses of several cytokines such as IL-1RA, IL-21 and all of the chemokines were found after adenovirus infection. Besides, the responses detected in the BL compartment were generally higher than those in the apical compartment, especially IL-1RA, IL-21, GM-CSF, GRO-α, SDF-1α and IL-8. CONCLUSION: During the infections of hAECs by adenovirus, higher viral replication was found in the apical compartment but cytokine and chemokine responses were higher in the basolateral compartment. This indicated viral entrance and replication occurred more in the apical part and major innate response took place in the basolateral part, which may make adenovirus infect human airway efficiently and cause different degree of severity.

Mycoplasma pneumoniae in pediatric patients: Do macrolide-resistance and/or delayed treatment matter?

BACKGROUND: Mycoplasma pneumoniae is a common pathogen for pneumonia in children, especially in the post-pneumococcal conjugate vaccination era. Though self-limited disease was found in the majority of the patients, severe diseases occurred occasionally. The emergence of macrolide resistance was reported worldwide. It is important to delineate whether macrolide resistance or delayed treatment affects outcome. METHODS: We retrospectively collected pediatric patients with M. pneumoniae infection confirmed by positive PCR in a tertiary medical center in Taiwan from 2010 to 2017. Patients' clinical characteristics, bacterial load, macrolide resistance and treatment outcome were analyzed. RESULTS: Among 471 children with positive M. pneumoniae PCR, 95% were diagnosed with pneumonia. Seventeen percent of patients had extrapulmonary complications, and 1.5% had respiratory failure. Delayed treatment was associated with prolonged fever after appropriate treatment, fulminant disease, and extrapulmonary manifestations (p < 0.05). The mean rate of macrolide resistance was 24% and macrolide resistance was related to longer febrile duration, longer hospital stay, lung consolidation and impaired liver function tests (P < 0.05). CONCLUSIONS: Macrolide resistance was fairly common and might lead to delayed appropriate antibiotic treatment. Delayed appropriate antimicrobial treatment, no matter macrolide resistance or not, was associated with more severe and/or prolonged diseases. Early diagnosis of M. pneumoniae as well as the awareness of macrolide resistance make early effective antibiotic treatment possible and may improve clinical outcomes.

Pathogens and outcomes in pediatric septic shock patients supported by extracorporeal membrane oxygenation.

BACKGROUND: Refractory septic shock is the leading cause of mortality in children. There is limited evidence to support extracorporeal membrane oxygenation (ECMO) use in pediatric septic shock. We described the etiology and outcomes of septic patients in our institution and attempted to find predictive factors. METHODS: We retrospectively reviewed 55 pediatric patients with septic shock who required ECMO support in a tertiary medical center from 2008 to 2015. Septic shock was defined as culture proved or clinical suspected sepsis with hypotension or end-organ hypoperfusion. ECMO would be applied when pediatric advanced life support steps were performed thoroughly without clinical response. Patient's demographics, laboratory parameters before and after ECMO, and outcomes were analyzed. RESULTS: Among 55 children with ECMO support, 31% of them survived on discharge. For 25 immunocompromised patients, causal pathogens were found in 17 patients: 7 due to bacteremia, 9 with preexisting virus infections and one with invasive fungal infection. Among 30 previously healthy patients, causal pathogens were found in 18 patients: 10 due to bacteremia (the most common was pneumococcus), 7 with preexisting virus infections including influenza (n = 4), adenovirus (n = 2), RSV, and 1 patient had mixed virus and bacterial infections. Predictive factors associated with death were arterial blood gas pH, CO2 and Glasgow Coma Scale (p < 0.05). SOFA score was a valuable predictive scoring system for outcome prediction (p < 0.05). CONCLUSIONS: Pediatric patients with refractory septic shock had high mortality rate and ECMO could be used as a rescue modality, and SOFA score could be applied to predict outcomes.

A user authentication scheme using physiological and behavioral biometrics for multitouch devices.

With the rapid growth of mobile network, tablets and smart phones have become sorts of keys to access personal secured services in our daily life. People use these devices to manage personal finances, shop on the Internet, and even pay at vending machines. Besides, it also helps us get connected with friends and business partners through social network applications, which were widely used as personal identifications in both real and virtual societies. However, these devices use inherently weak authentication mechanism, based upon passwords and PINs that is not changed all the time. Although forcing users to change password periodically can enhance the security level, it may also be considered annoyances for users. Biometric technologies are straightforward because of the simple authentication process. However, most of the traditional biometrics methodologies require diverse equipment to acquire biometric information, which may be expensive and not portable. This paper proposes a multibiometric user authentication scheme with both physiological and behavioral biometrics. Only simple rotations with fingers on multitouch devices are required to enhance the security level without annoyances for users. In addition, the user credential is replaceable to prevent from the privacy leakage.

A prospective, multicenter study of complementary/alternative medicine (CAM) utilization during definitive radiation for breast cancer.

PURPOSE: Although complementary and alternative medicine (CAM) utilization in breast cancer patients is reported to be high, there are few data on CAM practices in breast patients specifically during radiation. This prospective, multi-institutional study was conducted to define CAM utilization in breast cancer during definitive radiation. MATERIALS/METHODS: A validated CAM instrument with a self-skin assessment was administered to 360 Stage 0-III breast cancer patients from 5 centers during the last week of radiation. All data were analyzed to detect significant differences between users/nonusers. RESULTS: CAM usage was reported in 54% of the study cohort (n=194/360). Of CAM users, 71% reported activity-based CAM (eg, Reiki, meditation), 26% topical CAM, and 45% oral CAM. Only 16% received advice/counseling from naturopathic/homeopathic/medical professionals before initiating CAM. CAM use significantly correlated with higher education level (P<.001), inversely correlated with concomitant hormone/radiation therapy use (P=.010), with a trend toward greater use in younger patients (P=.066). On multivariate analysis, level of education (OR: 6.821, 95% CI: 2.307-20.168, P<.001) and hormones/radiation therapy (OR: 0.573, 95% CI: 0.347-0.949, P=.031) independently predicted for CAM use. Significantly lower skin toxicity scores were reported in CAM users vs nonusers, respectively (mild: 34% vs 25%, severe: 17% vs 29%, P=.017). CONCLUSION: This is the first prospective study to assess CAM practices in breast patients during radiation, with definition of these practices as the first step for future investigation of CAM/radiation interactions. These results should alert radiation oncologists that a large percentage of breast cancer patients use CAM during radiation without disclosure or consideration for potential interactions, and should encourage increased awareness, communication, and documentation of CAM practices in patients undergoing radiation treatment for breast cancer.

Imaging radiotherapy-induced apoptosis.

Prediction of response to therapy has been identified as an important tool to obtain a more customized treatment. It allows the selection of those patients who will benefit most from a particular therapy and prevents the exposure of patients to toxic, noneffective regimens. Recent technical advances and the introduction of novel markers in anatomical and functional imaging have created exciting opportunities for in vivo visualization and quantification of cell death. This review will focus on in vivo apoptosis imaging as a predictive marker for tumor response after radiation.

Dosimetric impact of post-operative seroma reduction during radiotherapy after breast-conserving surgery.

PURPOSE: Three boost radiotherapy (RT) techniques were compared to evaluate the dosimetric effect of seroma reduction during RT after breast-conserving surgery (BCS). MATERIALS AND METHODS: Twenty-one patients who developed seroma after BCS were included. Each patient underwent three CT scans: one week before RT (CT(-1)), in the third (CT(3)) and fifth (CT(5)) week of RT. For each patient, three plans were generated. (1) SEQ: whole breast irradiation planned on CT(-1,) sequential boost planned on CT(5), (2) SIB: simultaneous integrated boost planned on CT(-1), (3) SIB adaptive radiation therapy (SIB-ART): planned on CT(-1) and re-planned on CT(3). Irradiated volumes, mean lung (MLD) and maximum heart dose (HD(max)) were projected and compared on CT(5). RESULTS: On average 62% seroma reduction during RT was observed. Volumes receiving ≥ 107% of prescribed whole breast dose were significantly smaller with SIB-ART compared to SEQ and SIB. The undesired volume receiving ≥ 95% of prescribed total dose was also significantly smaller with SIB-ART. For SEQ, SIB-ART and SIB, respectively, small but significant differences were found in MLD (4.2 vs. 4.6 vs. 4.7 Gy) and in HD(max) for patients with left-sided breast cancer (39.9 vs. 35.8 vs. 36.9 Gy). CONCLUSIONS: This study demonstrates a dosimetric advantage for patients with seroma when simultaneous integrated boost is used with re-planning halfway through treatment.

Clinical applicability of cone-beam computed tomography in monitoring seroma volume change during breast irradiation.

PURPOSE: To determine whether cone-beam CT (CBCT) is effective in monitoring seroma reduction during breast irradiation when compared with conventional CT. PATIENTS AND METHODS: This study included 19 women with Stage T1-2 breast cancer treated with breast-conserving therapy. Each patient underwent two to four CT and multiple CBCT scans (mean, 8; range, 7-13 scans) at various time intervals during radiotherapy. Seroma were contoured by two observers on all scans and checked by one radiation oncologist. Seroma clarity was determined according to The British Columbia Cancer Agency Seroma Clarity Score scale, and conformity index (CI) of the two observers was evaluated. Correlations in seroma contours and seroma characteristics between CBCT and CT, as well as interobserver variation, were examined. RESULTS: The mean differences in seroma volume between CT and CBCT (3%, p = 0.3) and between the two observers (6%, p = 0.2) were not statistically significant. Seroma clarity correlated significantly with CI for both CT and CBCT (p = 0.02 and p = 0.001, respectively), indicating the higher the seroma clarity score, the greater the CI between the observers. With seroma clarity 3 or higher for CT and CBCT, a high level of observer concordance was shown (all CI of these scans were >or=50%). CONCLUSION: Volume discrepancy between CBCT and CT and between the two observers was not statistically significant. Seroma clarity influenced observers' ability to contour on CT or CBCT equally. Therefore, CBCT is a good clinical surrogate for CT in monitoring seroma reduction during breast radiotherapy, especially for patients with seroma clarity score 3 or higher.

Predicting early chemotherapy response with technetium-99m methoxyisobutylisonitrile SPECT/CT in advanced non-small cell lung cancer.

PURPOSE: The purpose of this study is to examine the prognostic value of prechemotherapy technetium-99m methoxyisobutylisonitrile ((99m)Tc-MIBI) uptake with single photon emission computed tomography/computed tomography (SPECT/CT) in relation to tumor size change measured by CT. METHODS: Eleven patients with stage IIIB/IV non-small cell lung cancer (NSCLC) underwent (99m)Tc-MIBI SPECT/CT within 24 h before starting platinum-containing chemotherapy. Following the Response Evaluation Criteria in Solid Tumors guidelines, 20 lesions from the 11 patients were available for evaluation. Maximum (C (max)) and mean (C (mean)) MIBI counts were calculated for each lesion. One-dimensional (1D; longest diameter) and two-dimensional (2D; area of the largest transverse surface) tumor measurements were assessed by two observers on the diagnostic CT and the response assessment CT after two cycles of chemotherapy. RESULTS: Bland-Altman analysis demonstrated no clinically significant bias between the observers. A solid correlation was found between (99m)Tc-MIBI C (mean) and change in the longest diameter (1D change) of the target lesion (rho = -0.62) using Spearman's rank correlation test. C (mean) also correlated negatively with change in the area of the largest transverse surface (2D change) of the target lesion (rho = -0.53). Furthermore, a correlation was established between (99m)Tc-MIBI C (max) and 1D change (rho = -0.56) in tumor size as well, though less strongly when compared to its C (mean) counterpart. CONCLUSIONS: Our series demonstrated solid, negative correlations between prechemotherapy (99m)Tc-MIBI uptake and tumor size change measured by CT for advanced NSCLC, particularly with C (mean) and 1D change.

Prognosis for mammographically occult, early-stage breast cancer patients treated with breast-conservation therapy.

PURPOSE: To compare mammographically occult (MamOcc) and mammographically positive (MamPos) early-stage breast cancer patients treated with breast-conservation therapy (BCT), to analyze differences between the two cohorts. METHODS AND MATERIALS: Our two cohorts consisted of 214 MamOcc and 2168 MamPos patients treated with BCT. Chart reviews were conducted to assess mammogram reports and method of detection. All clinical-pathologic and outcome parameters were analyzed to detect differences between the two cohorts. RESULTS: Median follow-up was 7 years. There were no differences in final margins, T stage, nodal status, estrogen/progesterone receptor status, or "triple-negative" status. Significant differences included younger age at diagnosis (p < 0.0001), more positive family history (p = 0.0033), less HER-2+ disease (p = 0.0294), and 1 degrees histology (p < 0.0001). At 10 years, the differences in overall survival, cause-specific survival, and distant relapse between the two groups did not differ significantly. The MamOcc cohort had more breast relapses (15% vs. 8%; p = 0.0357), but on multivariate analysis this difference was not significant (hazard ratio 1.0, 95% confidence interval 0.993-1.007, p = 0.9296). Breast relapses were mammographically occult in 32% of the MamOcc and 12% of the MamPos cohorts (p = 0.0136). CONCLUSIONS: Although our study suggests that there are clinical-pathologic variations for the MamOcc cohort vs. MamPos patients that may ultimately affect management, breast relapse after BCT was not significantly different. Breast recurrences were more often mammographically occult in the MamOcc cohort; consideration should be given to closer follow-up and alternative imaging strategies (ultrasound, breast MRI) for routine posttreatment examination. To our knowledge, this represents the largest series addressing the prognostic significance of MamOcc cancers treated with BCT.

Clinical factors associated with seroma volume reduction in breast-Conserving Therapy for early-stage breast cancer: a multi-institutional analysis.

PURPOSE: To correlate clinical factors with seroma volume and reduction; and to determine whether cone-beam CT (CBCT) could be used clinically to monitor seroma reduction. PATIENTS AND METHODS: This investigation included 102 women from five institutions with stage T1-2 breast cancer treated with breast-conserving therapy. Two CT scans were acquired: the planning CT (CT1) and a second CT (CT2) during radiotherapy (RT). Seroma was contoured on all scans, and correlations between seroma characteristics and clinical factors were investigated by univariate and multivariate analyses. In a substudy, 10 of the 102 patients received multiple CBCT scans during RT. Seroma were contoured by two observers in the substudy. Fifteen time points at which CT and CBCT were performed within 2 days were identified. The levels of correlation in seroma contours between CBCT and CT and between the two observers were examined. RESULTS: The mean relative seroma reduction from CT1 to CT2 was 54% (p < 0.001). A significant inverse relationship was found between relative seroma reduction per week and number of RT fractions given by univariate and multivariate analyses (p = 0.01, 0.03). The mean difference in contoured seroma volumes between CT and CBCT was 12% (3.3 cm(3)). When assessing the relative difference in seroma contours between Observer 1 and Observer 2, an interobserver difference of 12% was demonstrated. Neither discrepancy was clinically significant. CONCLUSIONS: Radiotherapy seems to hinder seroma reduction. Volume discrepancies between CBCT and CT were minor, with low interobserver variation, indicating that CBCT might be useful in monitoring seroma reduction.