Natural history and growth prediction model of pancreatic serous cystic neoplasms

OBJECTIVE

Serous cystic neoplasms (SCN) are benign pancreatic cystic neoplasms that may require resection based on local complications and rate of growth. We aimed to develop a predictive model for the growth curve of SCNs to aid in the clinical decision making of determining need for surgical resection.

METHODS

Utilizing a prospectively maintained pancreatic cyst database from a single institution, patients with SCNs were identified. Diagnosis confirmation included imaging, cyst aspiration, pathology, or expert opinion. Cyst size diameter was measured by radiology or surgery. Patients with interval imaging ≥3 months from diagnosis were included. Flexible restricted cubic splines were utilized for modeling of non-linearities in time and previous measurements. Model fitting and analysis were performed using R (V3.50, Vienna, Austria) with the rms package.

RESULTS

Among 203 eligible patients from 1998 to 2021, the mean initial cyst size was 31 mm (range 5-160 mm), with a mean follow-up of 72 months (range 3-266 months). The model effectively captured the non-linear relationship between cyst size and time, with both time and previous cyst size (not initial cyst size) significantly predicting current cyst growth (p < 0.01). The root mean square error for overall prediction was 10.74. Validation through bootstrapping demonstrated consistent performance, particularly for shorter follow-up intervals.

CONCLUSION

SCNs typically have a similar growth rate regardless of initial size. An accurate predictive model can be used to identify rapidly growing outliers that may warrant surgical intervention, and this free model (https://riskcalc.org/SerousCystadenomaSize/) can be incorporated in the electronic medical record.

Sequential surgeries following transversus abdominis release for abdominal wall reconstruction: Insights from a single-center analysis

INTRODUCTION

Abdominal surgery following transversus abdominis release (TAR) procedure commonly involves incisions through the previously implanted mesh, potentially creating vulnerabilities for hernia recurrence. Despite the popularity of the TAR procedure, current literature regarding post-AWR surgeries is limited. This study aims to reveal the incidence and outcomes of post-TAR non-hernia-related abdominal surgeries of any kind.

METHODS

Adult patients who underwent non-hernia-related abdominal surgery following ventral hernia repair with concurrent TAR procedure and permanent synthetic mesh in the Cleveland Clinic Center for Abdominal Core Health between January 2014 and January 2022 were queried from a prospectively collected database in the Abdominal Core Health Quality Collaborative. We evaluated 30-day wound morbidity, perioperative complications, and long-term hernia recurrence.

RESULTS

A total of 1137 patients who underwent TAR procedure were identified, with 53 patients (4.7%) undergoing subsequent non-hernia-related abdominal surgery post-TAR. Small bowel obstruction was the primary indication for reoperation (22.6%), and bowel resection was the most frequent procedure (24.5%). 49.1% of the patients required urgent or emergent surgery, with the majority (70%) having open procedures. Fascia closure was achieved by absorbable sutures in 50.9%, and of the open cases, fascia closure was achieved by running sutures technique in 35.8%. 20.8% experienced SSO, the SSOPI rate was 11.3%, and 26.4% required more than a single reoperation. A total of 88.7% were available for extended follow-up, spanning 17-30 months, resulting in a 36.1% recurrent hernia diagnosis rate.

CONCLUSIONS

Abdominal surgery following TAR surgery is associated with significant comorbidities and significantly impacts hernia recurrence rates. Our study findings underscore the significance of making all efforts to minimize reoperations after TAR procedure and offers suggestions on managing the abdominal wall of these complex cases.

Comparing oncologic and surgical outcomes of robotic and laparoscopic pancreatoduodenectomy in patients with pancreatic cancer: a propensity-matched analysis

INTRODUCTION

Minimally invasive Pancreatoduodenectomy (MIPD), or the Whipple procedure, is increasingly utilized. No study has compared laparoscopic (LPD) and robotic (RPD) approaches, and the impact of the learning curve on oncologic, technical, and post-operative outcomes remains relatively understudied.

METHODS

The National Cancer Database was queried for patients undergoing LPD or RPD from 2010 to 2020 with a diagnosis of pancreatic cancer. Outcomes were compared between approaches using propensity-score matching (PSM); the impact of annual center-level volume of MIPD was also assessed by dividing volume into quartiles.

RESULTS

A total of 3,342 patients were included. Most (n = 2,716, 81.3%) underwent LPD versus RPD (n = 626, 18.7%). There was a high rate (20.2%, n = 719) of positive margins. Mean length-of-stay (LOS) was 10.4 ± 8.9 days. Thirty-day mortality was 2.8% (n = 92) and ninety-day mortality was 5.7% (n = 189). PSM matched 625 pairs of patients receiving LPD or RPD. After PSM, there was no differences between groups based on age, sex, race, CCI, T-stage, neoadjuvant chemo/radiotherapy, or type of PD. After PSM, there was a higher rate of conversion to open (HR = 0.68, 95%CI = 0.50-0.92)., but there was no difference in LOS (HR = 1.00, 95%CI = 0.92-1.11), 30-day readmission (HR = 1.08, 95% CI = 0.68-1.71), 30-day (HR = 0.78, 95% CI = 0.39-1.56) or 90-day mortality (HR = 0.70, 95% CI = 0.42-1.16), ability to receive adjuvant therapy (HR = 1.15, 95% CI = 0.92-1.44), nodal harvest (HR = 1.01, 95%CI = 0.94-1.09) or positive margins (HR = 1.19, 95% CI = 0.89-1.59). Centers in lower quartiles of annual volume of MIPD demonstrated reduced nodal harvest (p = 0.005) and a higher rate of conversion to open (p = 0.038). Higher-volume centers had a shorter LOS (p = 0.012), higher rate of initiation of adjuvant therapy (p = 0.042), and, most strikingly, a reduction in 90-day mortality (p = 0.033).

CONCLUSION

LPD and RPD have similar surgical and oncologic outcomes, with a lower rate of conversion to open in the robotic cohort. The robotic technique does not appear to eliminate the "learning curve", with higher volume centers demonstrating improved outcomes, especially seen at minimum annual volume of 5 cases.

Gender representation in the Central Surgical Association: A call to action

BACKGROUND

Organizations such as the Central Surgical Association are important for promulgating advances in general surgery, but diversity and inclusion profoundly affect what is presented and discussed. The objective of this study was to evaluate gender representation trends at the Central Surgical Association and its annual meetings over the past 13 years.

METHODS

Publicly available Central Surgical Association meeting proceedings from 2010 to 2022 were reviewed for society leaders, new members, invited speakers and moderators, and contributors to scientific sessions (first authors, senior authors). Gender identity was assessed through professional online platforms. The 2017 and 2021 meetings were conjoined with the Midwest Surgical Association. Incomplete data were obtained from 2013 and 2020-2022.

RESULTS

A total of 2,158 individuals were reviewed, 554 (25.7%) of which were women. The overall trend of the absolute proportion of women participation increased by 1.8% per year (R2 = 0.7, P < .01). For leadership roles, 42/205 (20%) were women, with a 2.4% per year increase (R2 = 0.45, P = .02). For speaker roles, 82/384 (21.4%) were women, with a 2.2% increase per year (R2 = 0.6, P < .01). For scientific contributions, 253 first (35.9%) and 136 (19.3%) senior authors of 704 were women, with 1.5% (R2 = 0.4, P = .02) and 1.3% (R2 = 0.4, P = .03) increase per year, respectively.

CONCLUSION

There has been a positive trend in women's involvement at Central Surgical Association meetings for leaders, speakers, and scientific authors. Diversity allows variate experiences to contribute to surgical advancements; thus, measures by the Central Surgical Association to ensure adequate representation should continue.

Cholecystoenteric Stent-Related Complications: Rendering the Inoperable Patient Operable

INTRODUCTION

Cholecystoenteric stenting is an alternative treatment for cholecystitis. However, complications with this approach can render a need for surgical intervention.

METHODS

A case series of three patients undergoing surgery for a cholecystoenteric stent-related complication.

RESULTS

Patient 1 was a 42-year-old male with history of lung transplant who had a cholecystoenteric stent placed for acalculous cholecystitis. One year later the stent became occluded with return of symptoms. Endoscopic replacement failed. A laparoscopic cholecystectomy with modified Graham patch was performed. Patient 2 is a 73-year-old female with acalculous cholecystitis in the setting of metastatic colon cancer on FOLFOX. Antibiotic treatment failed. A cholecystoenteric stent was attempted, but the stent dislodged during deployment. The fistula tract was clipped, and a percutaneous cholecystostomy drain was placed, which noted a leak at the gallbladder infundibulum. The patient deteriorated clinically and was taken emergently for an open cholecystectomy. Patient 3 was a 71-year-old male with history of ischemic cardiomyopathy who had a cholecystogastric stent placed for necrotizing gallstone pancreatitis. The stent migrated into the gastrointestinal tract and he developed post-prandial pain. A cholecystectomy and modified Graham patch repair of the gastrotomy was performed. This failed as the gastrotomy was too close to the pylorus. He underwent re-operation with Heineke-Mikulicz pyloroplasty. All patients recovered without any cardiopulmonary complications.

CONCLUSION

With the increasing utility of cholecystoenteric stents, surgeons should be aware of the complications and have a plan for managing the duodenotomy or gastrotomy. Shared-medical decision-making involving surgeons should be applied when placing these stents.

Paving a Path to Gender Parity: Recent Trends in Participation of Women in an Academic Surgery Society (Society for Surgery of the Alimentary Tract)

INTRODUCTION

The proportion of women surgeons is increasing, although women in surgical leadership and research has not kept pace. The Society for Surgery of the Alimentary Tract (SSAT) pledged its commitment to diversity and inclusion in 2016. Our study sought to evaluate the temporal trend of gender representation in leadership, speakership, and research at SSAT.

METHODS

Publicly available SSAT meeting programs from 2010 to 2022 were reviewed to assess gender proportions within leadership positions (officers and committee chairs); invited speakerships, multidisciplinary symposia, and committee panel session moderators and speakers; and contributions to scientific sessions (moderator, first author and senior author). Verified individual professional profiles were analyzed to categorize gender as woman, man, or unavailable. Descriptive and trend analyses using linear regression and chi-squared testing were performed.

RESULTS

A total of 5506 individuals were reviewed; 1178 (21.4%) were identified as women and 4328 (78.6%) as men or did not have available data. The absolute proportion of total female participation increased by 1.05% per year (R2=0.82). There was a statistically significant difference in the total proportion of women participation before and after 2016 (18.5% vs. 27.1%, p<0.01). Increases in the proportion of women were demonstrated in leadership, invited speakerships, multidisciplinary symposia, committee panel sessions, research session moderators, and abstract first authors. The proportion of women senior authors remained stagnant.

CONCLUSION

Though this upward trajectory in SSAT women participation is encouraging, current trends predict that gender parity will not be reached until 2044.

Female Representation at the Association of Program Directors in Surgery Annual Meeting: Moving Towards Gender Equality

OBJECTIVE

This study aims to evaluate the state and changes over time of female representation in Association of Program Directors in Surgery (APDS) leadership and annual meeting presenters and session leaders.

DESIGN, SETTING, AND PARTICIPANTS

APDS conference programs from 2013 to 2022 were reviewed to identify society leadership and meeting presenters and session leaders. Verified online profiles were used to gather professional role and reported gender. Descriptive statistics and t-tests compared female representation in the first half (2013-2017, prior) and second half of data (2018-2022, current).

RESULTS

Leadership of APDS was an average 22% women, increasing from 13% in 2013 to 37% in 2022, and significantly increased from prior to current period (p = 0.0004). Conference presenters and session leaders were 42% women overall, increasing from 30% in 2013 to 52% in 2022. An average 33% staff surgeons, 54% trainees, 64% education scientists, and 51% medical student participants were female. Staff were 44% female in 2022 from 24% in 2013, significantly increased from prior to current period (p = 0.021). Comparing prior and current period cohorts, female presenters for paper sessions increased from 38% to 55% (p = 0.011), moderators from 15% to 39% (p = 0.046), and last author listed on presentation sessions from 18% to 32% (p = 0.010), while panelists, workshop directors, and presenters at all sessions increased without statistical significance. Female poster presenters decreased over time.

CONCLUSIONS

Female representation at APDS meetings has increased over time. Women are well represented compared to the 2022 member population of 36% women. While positions typically held by more senior members, such as leadership, panelists, moderators, and last authors remain lower than other roles, increases over time are encouraging. APDS female representation compares favorably to many other surgical societies. Translation of successful practices regarding gender representation utilized by APDS to other surgical organizations could expedite progress toward gender parity in the field.

Distressed community index as a predictor of presentation and postoperative outcomes in ventral hernia repair

BACKGROUND

We evaluated the impact of socioeconomic status on presentation, management, and outcomes of ventral hernias.

METHODS

The Abdominal Core Health Quality Collaborative was queried for adult patients undergoing ventral hernia repair. Socioeconomic quintiles were assigned using the Distressed Community Index (DCI): prosperous (0-20), comfortable (21-40), mid-tier (41-60), at-risk (61-80), and distressed (81-100). Outcomes included presenting symptoms, urgency, operative details, 30-day outcomes, and one-year hernia recurrence rates. Multivariable regression evaluated 30-day wound complications.

RESULTS

39,494 subjects were identified; 32,471 had zip codes (82.2%).Urgent presentation (3.6% vs. 2.3%) and contaminated cases (0.83% vs. 2.06%) were more common in the distressed group compared to the prosperous group (p < 0.001). Higher DCI correlated with readmission (distressed: 4.7% vs prosperous: 2.9%,p < 0.001) and reoperation (distressed 1.8% vs prosperous: 0.92%,p < 0.001). Wound complications were independently associated with increasing DCI (p < 0.05). Clinical recurrence rates were similar at one-year (distressed: 10.4% vs prosperous: 8.6%, p = 0.54).

CONCLUSIONS

Inequity exists in presentation and perioperative outcomes for ventral hernia repair and efforts should be focused on increasing access to elective surgery and improving postoperative wound care.

Postoperative Day 1 Drain Amylase After Pancreatoduodenectomy: Optimal Level to Predict Pancreatic Fistula

INTRODUCTION

Drain amylase on day 1 (DA-D1) after pancreaticoduodendectomy (PD) to predict occurrence of postoperative pancreatic fistula (POPF) is controversial. In this study, we evaluate the optimal DA-D1 level to predict clinically relevant POPF (CR-POPF).

METHODS

The 2014-2020 NSQIP pancreatectomy-targeted database was queried for patients who underwent elective PD. Perioperative data was extracted to determine development of POPF and CR-POPF per International Study Group of Pancreatic Fistula guidelines. Receiver operative curve (ROC) and Youden's index were used to assess the performance and optimal cutoff for DA-D1 to predict CR-POPF. The DA-D1 value was confirmed with a multivariable logistic regression to determine hazard ratios (HR) for CR-POPF and conditional logistic regression by modified fistula risk score (mFRS) subgroups.

RESULTS

A total of 6,087 patients with complete perioperative data were included. Mean DA-D1 was 2,897 ± 8,636 U/L; median drain duration was 5 days. CR-POPF was documented in 544 (8.9%) patients. DA-D1 ROC for CR-POPF had area under the curve of 0.779 (95%CI 0.759-0.798). Youden's index for the CR-POPF ROC coordinates had 77.6% sensitivity and 66.3% specificity, corresponding to DA-D1 values ≥ 720U/L as an optimal cutoff. CR-POPF was higher for patients with DA-D1 ≥ 720U/L (HR 4.6; p = 0.001). Patients DA-D1 < 720U/L with a negligible, low, intermediate, and high mFRS had respectively 1%, 3%, 4%, and 7% rate of CR-POPF.

CONCLUSION

DA-D1 < 720U/L after elective PD is a clinically useful predictor of CR-POPF. For patients with negligible to intermediate FRS, surgeons should consider utilizing DA-D1 < 720 U/L for removal of a drain on the first postoperative day.

The Impact of TP53 Mutations and Use of the TP53-Mutation-Reactivating Agent APR-246 on Metastatic Castrate-Sensitive Prostate Cancer

PURPOSE/OBJECTIVE(S)

TP53 mutations appear to be enriched over the spectrum of metastatic castration-sensitive prostate cancer (mCSPC) and are associated with worse survival outcomes. We chose to further explore the impact of dominant negative (DN) TP53 mutations on mCSPC progression and pro-metastatic behaviors in addition to studying the ability of APR-246, a small molecule targeting TP53 mutants, to blunt pro-metastatic behaviors.

MATERIALS/METHODS

We retrospectively analyzed 531 mCSPC patients who underwent next-generation sequencing. Patients were stratified by metastasis timing (synchronous if metastasis present at diagnosis or metachronous if arising after definitive treatment of localized disease) and the number of metastatic lesions (oligometastatic ≤5 or polymetastatic >5 lesions). Tumors were classified based on TP53 mutation status (missense, truncating, or wild-type [WT]) and dominant negativity, which was defined as the production of a mutant protein that reduces the residual WT protein's transcriptional activity according to the World Health Organization TP53 database. Clinical outcomes were radiographic progression-free survival (rPFS) and overall survival (OS), evaluated with Kaplan-Meier and multivariable Cox regression. To verify the impact of TP53 mutation on metastasis, we created isogenic 22Rv1 prostate cancer cell lines that carried either TP53 WT or TP53 R175H and tested this mutation for migration, invasion, and anchorage-independent growth. APR-246 (25-80 µM) was tested for anti-metastatic properties in vitro and anti-tumor growth in 22Rv1 xenografted nude mice.

RESULTS

In our cohort, 155 (29.2%) had a TP53 mutation, which mostly occurred in the DNA-binding domain (85.16%). DN TP53 mutations were associated with more aggressive disease states: DN TP53 mutations were enriched in patients with synchronous (vs. metachronous: 20.7% vs. 6.3%, p < 0.01) and polymetastatic disease (vs. oligometastatic: 14.4% vs. 7.9%, p < 0.01). On multivariable analysis, DN TP53 mutations were correlated with shorter rPFS (HR = 1.97, 95% CI: 1.31-2.98, p < 0.01) and OS (HR = 2.05, 95% CI: 1.14-3.68, p = 0.02) compared to those with TP53 WT. In vitro, 22Rv1 cells with DN TP53 R175H mutation had increased abilities to migrate, invade, and form colonies compared to TP53 WT. APR-246 treatment of TP53 R175H mutants blunted the pro-metastatic effects of the cell line in vitro (p < 0.01 for all assays by unpaired t-test). Interestingly, APR-246 also inhibited xenograft tumor growth of 22Rv1 TP53 R175H mutants (p < 0.0001 by two-way ANOVA).

CONCLUSION

DN TP53 mutations were associated with poorer survival outcomes for mCSPC patients. DN TP53 mutations also promoted prostate cancer pro-metastatic behaviors in vitro, which was effectively counteracted by APR-246, making it a promising treatment option that should be explored further in early-phase clinical studies.

Whole Regional Lymph Node Area Delineation with Deep Learning Model for Total Marrow and Lymphoid Irradiation

PURPOSE/OBJECTIVE(S)

Total body irradiation (TBI) has been performed for conditioning before hematopoietic stem cell transplantation. However, TBI can be related to diverse adverse events including radiation pneumonitis and cataract. Efforts to reduce these events include the total marrow irradiation (TMI) and total marrow and lymphoid irradiation (TMLI). Compared to TMI, TMLI requires more target delineations with lymph nodes which can be labor-intensive and time-consuming. However, with the TMI plans, the coverage to lymph node might be lower than TMLI and its clinical significance is unknown. In the current study, we aimed to develop a deep learning model for automatic delineation of whole regional lymph nodes area and assess the dose coverage of lymph nodes with TMI plans.

MATERIALS/METHODS

Whole regional lymph nodes (cervical, axillary, mediastinal, para-aortic, common iliac, external iliac, internal iliac, obturator, presacral, inguinal lymph nodes) were manually contoured by 3 radiation oncologists in 26 patients having whole body computed tomography (CT) images. Twenty patients were designated as the training/validation set and 6 patients as the testing set, and model was developed using the 'nnUNET' framework. The trained model was evaluated with dice coefficient score (DCS), precision, and recall. In addition, dose coverage of the automatically or manually delineated lymph nodes in TMI plans was calculated.

RESULTS

The mean value of DCS, precision, and recall of the trained model was 0.76, 0.81, and 0.74, respectively. Dose parameters for manually delineated lymph nodes in previously treated TMI plans showed the mean value of V100% (the percentage of volume receiving 100% of the prescribed dose), V95%, and V90% to be 46.50%, 62.12%, and 73.68%, respectively. The highest V90% was observed in presacral (93.61%), axillary (90.40%), obturator (88.78%), and internal iliac lymph nodes (84.67%). In contrast, the lowest V90% was identified in inguinal (47.95%), cervical (61.69%), and para-aortic (65.75%) and external iliac lymph nodes (68.97%). For automatically delineated lymph nodes, the mean value of V100%, V95%, and V90% of TMI plan was 38.35%, 55.06%, and 67.84%, respectively. The difference with dose coverage of lymph node between delineated manually and automatically was not statistically significant.

CONCLUSION

Automatic delineation of lymph node using deep learning showed the potential to reduce the labor-intensive process of TMLI. When treated with TMI, the coverage of inguinal, cervical, para-aortic and external iliac lymph nodes was lower than expected.

Relationships between Microbiome and Response to Neoadjuvant Chemoradiotherapy in Rectal Cancer

PURPOSE/OBJECTIVE(S)

Gut microbiome is known to be involved in antitumor immunotherapy and chemotherapy responses; however, few research has focused on the role of gut microbiome in the setting of concurrent chemoradiotherapy (CCRT). In this study, we investigated the tumor microbiome dynamics in patients undergoing neoadjuvant CCRT for locally advanced rectal cancer and sought to determine whether the diversity and composition of microbiome affect treatment response.

MATERIALS/METHODS

A total of 103 samples from 26 patients with locally advanced rectal cancer were collected and 16S ribosomal RNA amplicon sequencing was performed. All patients underwent neoadjuvant CCRT followed by surgical resection between 2008 and 2016. Samples were obtained from both tumor and normal rectal tissue at pre- and post-CCRT. According to the American Joint Committee on Cancer tumor regression grading (TRG) system, patients were divided into responders (TRG 0, 1) and non-responders (TRG 2, 3). We performed diversity, taxonomy, and network analyses to compare responders and non-responders. Then, we established the Bayesian network model to predict treatment response in patients with rectal cancer.

RESULTS

Overall, we detected 1260 microbial genera from 287 families, 132 orders, 56 classes, and 32 phyla in the bacteria kingdom. Between tumor and normal rectal tissues, there was no difference in microbial diversity and composition. On the other hand, there was a significant decrease in diversity and compositional alterations when comparing pre- and post-CCRT samples (all p<0.001). Ten patients (38.5%) were classified as responders and 16 patients (61.5%) were classified as non-responders. In both groups, CCRT significantly reduced microbial diversity and altered their composition, but it was more pronounced in non-responders. In taxonomic analysis of pre-CCRT samples, butyrate-producing bacteria were differentially enriched in responders. Meanwhile, in post-CCRT samples, opportunistic pathogen were overrepresented in non-responders. The network analysis revealed that butyrate-producing bacteria had strong interactions in responders, whereas opportunistic pathogen demonstrated strong interactions in non-responders (Pearson's coefficient>0.5). Finally, five microbes were selected as the optimal set for the response prediction model, which yielded an area under the curve value of 82.33%.

CONCLUSION

CCRT significantly changed the diversity and composition of microbiome, especially in non-responders. Several microbes might be related with treatment response. These findings highlight the potential of microbiome to play an important role as a biomarker in patients with rectal cancer. (NCT02533271).

The role of minimally invasive surgery in resectable distal pancreatic adenocarcinoma

BACKGROUND

In distal pancreatectomy (DP) for pancreatic ductal adenocarcinoma (PDAC), we hypothesize that minimally invasive DP (MIDP) carries short-term benefits over ODP (ODP) in the absence of postoperative pancreatic fistula (POPF).

METHODS

NSQIP database was queried to select patients who underwent DP for PDAC with available report on POPF. The population was divided into No-POPF vs. POPF groups. In each group, propensity-score matching was applied to compare 30-day outcomes of ODP vs. MIDP.

RESULTS

There were 2,824 patients; 2,332 (82%) had No-POPF and 492 (21%) had POPF. In No-POPF patients, 921 pairs were matched between ODP and MIDP. MIDP patients had slightly longer operations (227 vs. 205 minutes; p < 0.001), but lower rates of surgical site complications (1% vs. 2.9%; p = 0.002), postoperative transfusion (7.1% vs. 11.0%; p = 0.003), overall morbidity (21.1% vs. 26.3%; p = 0.009), and one-day shorter median length of stay (LOS) (5 vs. 6 days; p = 0.001). In the POPF group, 172 pairs were matched. There was no difference in morbidity, mortality, reoperation, LOS, and home discharge. Similar conclusions were drawn in the intention-to-treat and per-protocol analyses.

CONCLUSION

POPF is common following DP for PDAC. In the absence of POPF, MIDP is associated with fewer postoperative morbidities and shorter LOS.

Identifying Common Topics in Patient Portal Messages with Unsupervised Natural Language Processing

PURPOSE/OBJECTIVE(S)

Patient portal messaging is an increasingly important form of communication between patients and medical providers. This has become particularly relevant in oncology, where patients undergo intense longitudinal treatments that require frequent communication regarding symptoms, appointments, and diagnostic results. The rise in the volume of these messages has significantly increased the workload of medical providers and consequent physician burn-out. Natural language processing (NLP), particularly transformer-based models, may offer an automated approach to characterize the content of patient messages and improve message triage and routing. In this study, we employed a state-of-the-art language model (Bidirectional Encoder Representations from Transformers; BERT) to identify data-derived categories of representative topics from real-world data thereby providing basic information to build an appropriate routing system.

MATERIALS/METHODS

Patient-generated portal messages sent to a messaging pool for a single institution radiation oncology department from 2014 to 2023 were extracted. BERTopic, an NLP-based topic modeling technique based on BERT was optimized for topic modeling of patient messages. Uniform Manifold Approximation and Projection (UMAP) was used to reduce dimensionality and visualize topic relationships across messages. The BERTopic-identified topic categories were subsequently labeled manually by one of the physician investigators. Differences of number of messages over time were assessed using t-tests.

RESULTS

A total of 47,492 messages were retrieved. The average number of messages per month from a single patient ranged from 1 to 18 (median 1.67, interquartile range 1.0-2.4). The total volume of patient messages showed a ten-fold increase over the study period, with 101 messages per month sent in 2014 and 999 messages per month in 2022 (p<0.001). BERTopic initially identified 35 topics whose relationships and degrees of overlap were visualized by UMAP. Due to physician-identified similarities, these topics were reduced into 13 categories. The most frequent topic category was messages about laboratory tests or imaging studies: 24.3%, followed by messages expressing appreciation: 18.9%, scheduling discussions: 15.6%, symptom-related messages: 11%, and treatment-related messages: 10.7%.

CONCLUSION

Patient portal messages sent to a single institution radiation oncology department have increased dramatically in volume since implementation, corresponding to a broader national trend. NLP successfully identified common subject themes across patient messages, many of which are related to scheduling. This presents potential opportunities to apply NLP to automate message routing in the future.

Impact of the New ESTRO-ACROP Target Volume Delineation Guideline on Breast-Related Complications after Implant-Based Reconstruction and Postmastectomy Radiotherapy

PURPOSE/OBJECTIVE(S)

The European Society for Radiotherapy and Oncology Advisory Committee in Radiation Oncology Practice (ESTRO-ACROP) recently updated a new target volume delineation guideline for postmastectomy radiotherapy (PMRT) after implant-based reconstruction. This study aimed whether this change has impact on breast-related complications.

MATERIALS/METHODS

We retrospectively reviewed patients who underwent PMRT after mastectomy with tissue expander or permanent implant insertion from 2016 to 2021. In total, 412 patients were included; 277 received RT by the new ESTRO-ACROP target delineation (ESTRO-T), and 135 received RT by conventional target delineation (CONV-T). The primary endpoint was comparison between the target groups of major breast-related complication, including infection, capsular contracture, deformity and necrosis requiring re-operation or re-hospitalization during follow-up after RT or delayed implant replacement. Complications were evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0., and capsular contracture was graded by the Baker Classification.

RESULTS

The median follow-up was 29.5 months (range, 0.3-76.8). The 1-, 2-, and 3-year incidence rates of major breast-related complication were 5.7%, 10.0%, and 11.6% in the ESTRO-T group, and 8.2%, 13.8%, and 14.7% in the CONV-T groups; it did not show a difference between the groups (P = 0.55). In multivariate analyses, target delineation is not significantly associated with the major complications (hazard ratio [HR] = 0.93; P = 0.83, Table 1). There was no significant difference between the ESTRO-T and CONV-T groups in the incidence of any breast-related complications (3-year cumulative incidence, 37.3% vs. 29.4%, respectively; P = 0.28). Symptomatic RT-induced pneumonitis rates were 2.7% in the ESTRO-T group (7 patients) and 2.2% in the CONV-T group (3 patients). Only one local recurrence event occurred in the ESTRO-T group, which was within the ESTRO-target volume.

CONCLUSION

Target volume delineation according to the new ESTRO-ACROP guideline did not reduce the risk of major or any breast-related complications. As the dosimetric benefits of heart and lung have been reported, further analyses with long-term follow-up are necessary to evaluate whether it could be connected to better clinical outcomes.

The Early and Late Effects of High-Dose Irradiation on Cardiac Injury in a Rat Model

PURPOSE/OBJECTIVE(S)

Radiation-induced heart disease is a critical concern after radiotherapy (RT) for thoracic and chest wall tumors; however, the biological effects and mechanisms are still unknown. In this study, we investigated dose-responsive functional and pathological changes in rat hearts at 1, 3, and 5 months after high-dose irradiation. Then, we sought to elucidate the underlying mechanisms of myocardial changes induced by high-dose irradiation.

MATERIALS/METHODS

Whole hearts of rats (N = 72) were irradiated with a single fraction of 0 (control), 10, 20, or 30 Gy and allocated into three groups according to the follow-up period after RT: baseline, one, three, and five months. During follow-up periods, rats underwent functional evaluation by electrocardiogram and echocardiography at 4-week intervals. If a rat's body weight decreased by 20% or more, it was considered premature death, and the heart was explanted immediately. Otherwise, all hearts were explanted when each group's follow-up period was completed. Pathological changes of cardiac structures were evaluated using a light microscope after staining with hematoxylin-eosin, Masson's trichrome, α-smooth muscle actin, desmin, and connexin-43.

RESULTS

All rats irradiated with 0 or 10 Gy completed their follow-up periods with continuously increasing body weight. However, among rats irradiated with 20 or 30 Gy, half of the rats died prematurely at 8-10 weeks after RT, and the remainder survived until 20 weeks. In echocardiography, increased wall thickness and E/E' ratio, and decreased end-diastolic volume were observed in 20-30 Gy groups compared to 0-10 Gy groups from 8 weeks after RT. Ejection fraction was preserved in all groups. In pathological review, 20-30 Gy groups demonstrated diffuse inflammation and vacuolization at 4 weeks. Then, at 8 weeks, prominent fibrotic changes and intercalated disc disruptions were observed. Notably, fibrotic changes were somewhat resolved at 20 weeks, but intercalated disc disruptions were not repaired until 20 weeks. The 0 and 10 Gy groups showed no significant changes in both functional and pathological analyses.

CONCLUSION

Rats irradiated with 20 or 30 Gy showed diastolic dysfunction in functional analysis and time-dependent myocardial changes in pathological analysis. Radiation-induced fibrosis might be a "reactive" fibrosis, which could proceed to either a profibrotic course (progressive fibrosis) or an anti-fibrotic course (recovery phase). Further studies are needed to identify whether high-dose irradiation-induced cardiac fibrosis could be reversible.

Pattern and Complication of Reconstructed Breast Cancer Patients Who Received Postmastectomy Radiotherapy in the National Health Insurance Service Cohort

PURPOSE/OBJECTIVE(S)

This study aimed to analyze the nationwide pattern of reconstruction after mastectomy in patients with breast cancer who received postmastectomy radiotherapy (PMRT) and to compare complications according to fractionation and reconstruction procedures.

MATERIALS/METHODS

By using claim data from the National Health Insurance Service (NHIS) database, we analyzed breast cancer patients who received PMRT and underwent reconstruction between 2015 and 2020. We defined the grade ≥ 3 complications as the primary endpoint which involved hospital admission to the plastic surgery department. The complication was identified by using the procedure code for debridement and the International Classification of Diseases 10th codes for wound infections, dehiscence, necrosis, and mechanical complication of breast prosthesis and implant. The propensity score matching method was adopted to constitute the matched cohort between the hypofractionated fractionation (HF) and the conventional fractionation (CF), adjusted for age, diabetes, hypertension, obesity, smoking history, PMRT technique, use of bolus, year of PMRT delivery, and reconstruction method. Logistic regression was performed to evaluate the association between complication and variables.

RESULTS

Altogether 4,553 patients were analyzed: 1,395 (30.6%) in the HF group and 3,158 (69.4.%) in the CF group. The use of HF has steadily increased from 20.1% in 2015 to 42.2% in 2020. Immediate implant reconstruction (36.8%) method was the most frequently used, followed by immediate autologous (33.3%) and two-stage implant reconstruction methods (19.6%). In the matched cohort (N = 2,052), the major complication rate was not significantly different between the HF group and the CF group (5.9% [60/1,026] vs. 5.4% [55/1,026], P = 0.568) with the median follow-up of 30.9 months (range, 6.0-82.1). Surgical debridement was performed in 3.3% [34/1026] of the HF group and 3.5% [36/1026] of the CF group (P = 0.808). HF was not associated with major complications (odds ratio (OR) 1.09, 95% CI 0.75-1.59, P = 0.128).

CONCLUSION

In a nationwide insurance cohort, the complication rate was not significantly different between the HF group and the CF group. Our data suggest HF for reconstructed breasts is comparable to CF. However, consultation for fractionation regimen for reconstructed breast cancer patients may be still required at time of consideration of PMRT.

Safety and Efficacy of Stereotactic Body Radiotherapy for Ultra-Central Thoracic Tumors

PURPOSE/OBJECTIVE(S)

Stereotactic body radiotherapy (SBRT) is increasingly utilized in the management of ultra-central thoracic tumors, although concerns regarding significant toxicity remain. We sought to evaluate the toxicity and efficacy of SBRT to these tumors at our institution.

MATERIALS/METHODS

Patients with ultra-central lung tumors or nodes treated at our institution with SBRT between 2009 and 2019 were retrospectively reviewed. Ultra-central was defined as having the planning target volume (PTV) overlapping or abutting the central bronchial tree and/or esophagus. All SBRT plans were generated with homogenous dose distributions using target coverage objectives of ITV V100% >99%, PTV V95% >99%, and an ideal PTV Dmax <105% (strict <120%). All plans were reviewed in quality assurance rounds by a team of dosimetrists, physicists, and radiation oncologists. The primary endpoint was incidence of severe toxicity (ST), defined as SBRT-related grade ≥3 toxicities, graded using the Common Terminology Criteria for Adverse Events V5.0. Secondary endpoints included local failure (LF), progression-free survival (PFS) and overall survival (OS). Competing risk analysis was used to estimate incidence and predictors of ST and LF, with death as a competing risk. Kaplan-Meier method was used to estimate PFS and OS.

RESULTS

A total of 154 patients who received 162 ultra-central courses of SBRT were included, with a median follow-up of 21.5 months. Treatment intent was most commonly for oligoprogression (46%), oligometastasis (30%), followed by curative (20%). The most frequent tumor histologies were NSCLC (41%) and RCC (26%). SBRT prescription doses ranged from 30-55 Gy in 5 fractions (BED10 range 48-115 Gy). The most common prescription was 50 Gy in 5 fractions (42%). The cumulative incidence of ST was 8.9% at 3-years. The most common ST was pneumonitis (n = 4). Notable toxicities included bronchopleural fistula (n = 2, grade 3 and 4), bronchial stricture (n = 1, grade 3), and esophagitis leading to bleeding (n = 1, grade 4). There were no esophageal strictures or perforations, and no bronchial bleeds. There was 1 possible treatment related death from pneumonitis/pneumonia. Predictors of any ST included increased lung V5 Gy, decreased PTV V95%, and not having prior radiation therapy to the chest. The cumulative incidence of LF was 4.8%, 11% and 14% at 1-, 2-, and 3-years respectively. Predictors of LF included younger age, and greater volume of overlap between the PTV and esophagus. Median PFS was 8.4 months, while median OS was 3.7 years.

CONCLUSION

In one of the largest case series of ultra-central thoracic SBRT reported to date, homogenously prescribed SBRT plans were associated with relatively low rates of ST and LF across a variety of treatment indications. Predictors of ST should be interpreted recognizing the heterogeneity in toxicities observed. Identified predictors of both ST and LF can contribute to future work to optimize the therapeutic ratio in treatment of ultra-central thoracic tumors.

Biliary Anatomy Quiz: Test Your Knowledge

One of the most common surgical procedures performed in the USA is the cholecystectomy. Understanding biliary anatomy, which includes the gallbladder and extrahepatic biliary tree, is essential for every general surgeon. This quiz includes clinically relevant anatomy and radiology questions for the current and future surgeon at every level of training, and we hope it will be a useful adjunct to one's review.

MRI Features May Predict Molecular Features of Glioblastoma in Isocitrate Dehydrogenase Wild-Type Lower-Grade Gliomas

BACKGROUND AND PURPOSE

Isocitrate dehydrogenase (IDH) wild-type lower-grade gliomas (histologic grades II and III) with epidermal growth factor receptor (EGFR) amplification or telomerase reverse transcriptase (TERT) promoter mutation are reported to behave similar to glioblastoma. We aimed to evaluate whether MR imaging features could identify a subset of IDH wild-type lower-grade gliomas that carry molecular features of glioblastoma.

MATERIALS AND METHODS

In this multi-institutional retrospective study, pathologically confirmed IDH wild-type lower-grade gliomas from 2 tertiary institutions and The Cancer Genome Atlas constituted the training set (institution 1 and The Cancer Genome Atlas, 64 patients) and the independent test set (institution 2, 57 patients). Preoperative MRIs were analyzed using the Visually AcceSAble Rembrandt Images and radiomics. The molecular glioblastoma status was determined on the basis of the presence of EGFR amplification and TERT promoter mutation. Molecular glioblastoma was present in 73.4% and 56.1% in the training and test sets, respectively. Models using clinical, Visually AcceSAble Rembrandt Images, and radiomic features were built to predict the molecular glioblastoma status in the training set; then they were validated in the test set.

RESULTS

In the test set, a model using both Visually AcceSAble Rembrandt Images and radiomic features showed superior predictive performance (area under the curve = 0.854) than that with only clinical features or Visually AcceSAble Rembrandt Images (areas under the curve = 0.514 and 0.648, respectively; P < . 001, both). When both Visually AcceSAble Rembrandt Images and radiomics were added to clinical features, the predictive performance significantly increased (areas under the curve = 0.514 versus 0.863, P < .001).

CONCLUSIONS

MR imaging features integrated with machine learning classifiers may predict a subset of IDH wild-type lower-grade gliomas that carry molecular features of glioblastoma.

Reporting and Abstracting Variability in Technical Standards for Breast Cancer Operations

BACKGROUND

The American College of Surgeons Commission on Cancer has incorporated documentation of critical elements outlined in Operative Standards for Cancer Surgery into revised standards for cancer center accreditation. This study assessed the current documentation of critical elements in partial mastectomy (PM) and sentinel lymph node biopsy (SLNB) operative reports.

MATERIALS AND METHODS

Operative reports for PM + SLNB at a single academic institution from 2013 to 2018 were reviewed for compliance and surveyor interobserver reliability with the Oncologic Elements of Operative Record defined in Operative Standards and compared with a nonredundant American Society of Breast Surgeons Mastery of Breast Surgery (MBS) quality measure for specimen orientation.

RESULTS

Ten reviewers each evaluated 66 PM + SLNB operative reports for 13 Oncologic Elements and one MBS measure. No operative records reported all critical elements for PM + SLNB or PM alone. Residents completed 36.4% of operative reports: Element documentation was similar for PM but varied significantly for SLNB between resident and attending authorship. Combined reporting performance and interrater reliability varied across all elements and was highest for the use of SLNB tracer (97.1% and κ = 0.95, respectively) and lowest for intraoperative assessment of SLNB (30.6%, κ = 0.43). MBS specimen orientation had both high proportion reported (87.0%) and interrater reliability (κ = 0.84).

CONCLUSIONS

Adherence to reporting critical elements for PM and SLNB varied. Whether differential compliance was tied to discrepancies in documentation or reviewer abstraction, clarification of synoptic choices may improve reporting consistency. Evolving techniques or technologies will require continuous appraisal of mandated reporting for breast surgery.

Changes in Bone Mineral Density After Kidney Transplantation

BACKGROUND

Numerous studies have shown that osteoporosis is common in kidney transplant recipients. However, the change in bone mineral density after kidney transplantation (KT) is not fully understood.

METHODS

Thirty-nine kidney transplant recipients with bone densitometry at pretransplant and 24 months after KT were reviewed.

RESULTS

The recipients' median age (44.5 ± 10.7 years) and dialysis duration before KT (4.2 ± 3.4 years) were recorded. The T-scores of the lumbar spine and femur neck at 24 months after KT were positively associated with the respective pretransplant T-score (P < .001 in the lumbar spine and P < .001 in the femur neck). However, the T-score after KT did not show significant change (P = .680 in lumbar spine, P = .093 in femur neck). Changes in the T-scores of the lumbar spine and femur neck over 24 months (delta T-score) were negatively associated with the respective pretransplant T-scores (P = .001 in lumbar spine, P = .026 in femur neck). Changes in the T-scores of the lumbar spine and femur neck over 24 months (delta T-score) were also associated with the pretransplant T-scores after the adjustment of other variables.

CONCLUSION

The change of bone mineral density was related with pretransplant bone mineral density. Careful follow-up of bone densitometry for KT recipients was needed.

Suspected Frequent Relapsing IgG4-related Lung Disease in Kidney Transplant Patient: A Case Report

Besides the initial description of IgG4-related pancreatic disease, other sites are now commonly involved. However, occurrence of IgG4-related disease is rare in organ transplanted patients. A 57-year-old man who received a kidney transplantation presented with recurrent dyspnea on exertion. A computed tomography scan of the chest revealed bilateral interlobular septal thickening and multiple tubular and branching small nodular lesions in the right upper lobe, and mass-like consolidation of the left middle lobe. Despite no elevation of serum IgG4 level, a percutaneous core needle biopsy on consolidative mass showed interstitial fibrosis and infiltration of IgG4-positive plasma cells to be more than > 20 per high power field. After treatment with glucocorticoids and rituximab, the consolidative mass of the left middle lobe disappeared.

Whole-Tumor Histogram and Texture Analyses of DTI for Evaluation of IDH1-Mutation and 1p/19q-Codeletion Status in World Health Organization Grade II Gliomas

BACKGROUND AND PURPOSE

Prediction of the isocitrate dehydrogenase 1 (IDH1)-mutation and 1p/19q-codeletion status of World Health Organization grade ll gliomas preoperatively may assist in predicting prognosis and planning treatment strategies. Our aim was to characterize the histogram and texture analyses of apparent diffusion coefficient and fractional anisotropy maps to determine IDH1-mutation and 1p/19q-codeletion status in World Health Organization grade II gliomas.

MATERIALS AND METHODS

Ninety-three patients with World Health Organization grade II gliomas with known IDH1-mutation and 1p/19q-codeletion status (18 IDH1 wild-type, 45 IDH1 mutant and no 1p/19q codeletion, 30 IDH1-mutant and 1p/19q codeleted tumors) underwent DTI. ROIs were drawn on every section of the T2-weighted images and transferred to the ADC and the fractional anisotropy maps to derive volume-based data of the entire tumor. Histogram and texture analyses were correlated with the IDH1-mutation and 1p/19q-codeletion status. The predictive powers of imaging features for IDH1 wild-type tumors and 1p/19q-codeletion status in IDH1-mutant subgroups were evaluated using the least absolute shrinkage and selection operator.

RESULTS

Various histogram and texture parameters differed significantly according to IDH1-mutation and 1p/19q-codeletion status. The skewness and energy of ADC, 10th and 25th percentiles, and correlation of fractional anisotropy were independent predictors of an IDH1 wild-type in the least absolute shrinkage and selection operator. The area under the receiver operating curve for the prediction model was 0.853. The skewness and cluster shade of ADC, energy, and correlation of fractional anisotropy were independent predictors of a 1p/19q codeletion in IDH1-mutant tumors in the least absolute shrinkage and selection operator. The area under the receiver operating curve was 0.807.

CONCLUSIONS

Whole-tumor histogram and texture features of the ADC and fractional anisotropy maps are useful for predicting the IDH1-mutation and 1p/19q-codeletion status in World Health Organization grade II gliomas.

Prediction of IDH1-Mutation and 1p/19q-Codeletion Status Using Preoperative MR Imaging Phenotypes in Lower Grade Gliomas

BACKGROUND AND PURPOSE

WHO grade II gliomas are divided into three classes: isocitrate dehydrogenase (IDH)-wildtype, IDH-mutant and no 1p/19q codeletion, and IDH-mutant and 1p/19q-codeleted. Different molecular subtypes have been reported to have prognostic differences and different chemosensitivity. Our aim was to evaluate the predictive value of imaging phenotypes assessed with the Visually AcceSAble Rembrandt Images lexicon for molecular classification of lower grade gliomas.

MATERIALS AND METHODS

MR imaging scans of 175 patients with lower grade gliomas with known IDH1 mutation and 1p/19q-codeletion status were included (78 grade II and 97 grade III) in the discovery set. MR imaging features were reviewed by using Visually AcceSAble Rembrandt Images (VASARI); their associations with molecular markers were assessed. The predictive power of imaging features for IDH1-wild type tumors was evaluated using the Least Absolute Shrinkage and Selection Operator. We tested the model in a validation set (40 subjects).

RESULTS

Various imaging features were significantly different according to IDH1 mutation. Nonlobar location, larger proportion of enhancing tumors, multifocal/multicentric distribution, and poor definition of nonenhancing margins were independent predictors of an IDH1 wild type according to the Least Absolute Shrinkage and Selection Operator. The areas under the curve for the prediction model were 0.859 and 0.778 in the discovery and validation sets, respectively. The IDH1-mutant, 1p/19q-codeleted group frequently had mixed/restricted diffusion characteristics and showed more pial invasion compared with the IDH1-mutant, no codeletion group.

CONCLUSIONS

Preoperative MR imaging phenotypes are different according to the molecular markers of lower grade gliomas, and they may be helpful in predicting the IDH1-mutation status.

The Initial Area Under the Curve Derived from Dynamic Contrast-Enhanced MRI Improves Prognosis Prediction in Glioblastoma with Unmethylated MGMT Promoter

BACKGROUND AND PURPOSE

Although perfusion and permeability MR parameters have known to have prognostic value, they have reproducibility issues. Our aim was to evaluate whether the initial area under the time-to-signal intensity curve (IAUC) derived from dynamic contrast-enhanced MR imaging can improve prognosis prediction in patients with glioblastoma with known MGMT status.

MATERIALS AND METHODS

We retrospectively examined 88 patients with glioblastoma who underwent preoperative dynamic contrast-enhanced MR imaging. The means of IAUC values at 30 and 60 seconds (IAUC30_mean and IAUC60_mean) were extracted from enhancing tumors. The prognostic values of IAUC parameters for overall survival and progression-free survival were assessed with log-rank tests, according to the MGMT status. Multivariate overall survival and progression-free survival models before and after adding the IAUC parameters as covariates were explored by net reclassification improvement after receiver operating characteristic analysis for 1.5-year overall survival and 1-year progression-free survival and by random survival forest.

RESULTS

High IAUC parameters were associated with worse overall survival and progression-free survival in the unmethylated MGMT group, but not in the methylated group. In the unmethylated MGMT group, 1.5-year overall survival and 1-year progression-free survival prediction improved significantly after adding IAUC parameters (overall survival area under the receiver operating characteristic curve, 0.86; progression-free survival area under the receiver operating characteristic curve, 0.74-0.76) to the model with other prognostic factors (overall survival area under the receiver operating characteristic curve, 0.81; progression-free survival area under the receiver operating characteristic curve, 0.69; P < .05 for all) except in the case of IAUC60_mean for 1-year progression-free survival prediction (P = .059). Random survival forest models indicated that the IAUC parameters were the second or most important predictors in the unmethylated MGMT group, except in the case of the IAUC60_mean for progression-free survival.

CONCLUSIONS

IAUC can be a useful prognostic imaging biomarker in patients with glioblastoma with known MGMT status, improving prediction of glioblastoma prognosis with the unmethylated MGMT promoter status.

Application of iodinated starch powder using an atomizer spray gun - a new and effective tool to evaluate hypohidrosis

BACKGROUND

Hypohidrosis is defined as diminished sweating in response to an appropriate thermal or sympathetic stimulus. When encountered in a clinical setting, it necessitates an accurate documentation of its pattern and extent to prognosticate the risk of associated heat-related illnesses. This can be achieved by thermoregulatory sweat testing which includes a starch-iodine sweat test that can be administered via various methods.

OBJECTIVE

To describe and evaluate the effectiveness and safety of a novel method of using an atomizer spray gun in administering the starch-iodine test.

METHODS

We describe the administration of the starch-iodine test via an atomizer spray gun (Series 700 Lab Model; Mitsuba Systems, Mumbai, India). The method was utilized for the evaluation of 30 individuals who presented with symptoms of hypohidrosis.

RESULTS

Application of iodinated starch powder prepared in-house with the atomizer spray gun achieved a lightweight and homogeneous coat on our patients' skin which allowed for clear visualization of the sweating pattern in areas of anhidrosis. The sharp demarcation of the pathological regions enabled the precise calculation of the affected body surface area of impaired sweating. Unlike the starch-iodine tests using the Minor and Wada methods, neither staining of the skin nor irritation was detected in this method.

CONCLUSION

We report a novel method of using an atomizer spray gun to perform the starch-iodine test in a rapid, reproducible, effective, and safe manner suitable for use in the clinical evaluation of hypohidrosis.

Low pulmonary function is related with a high risk of sarcopenia in community-dwelling older adults: the Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2011

Sarcopenia is the age-related reduction of skeletal muscle mass in older individuals. Respiratory muscle strength may be related to skeletal muscle mass and, thus, the present study attempted to estimate the risk of sarcopenia relative to decreased pulmonary function. The present findings demonstrated that low pulmonary function was associated with low muscle mass in community-dwelling older adults.

INTRODUCTION

Lean body mass is related to pulmonary function in patients with chronic obstructive pulmonary disease (COPD). However, the relationship between muscle mass and pulmonary function in healthy older adults has yet to be clarified. Thus, the present study investigated the association of pulmonary function with muscle mass in an older community-dwelling Korean population.

METHODS

This study included 463 disease-free subjects over 65 years of age who underwent anthropometric measurements, laboratory tests, spirometry, and the estimation of appendicular skeletal muscle (ASM) mass in the 2008-2011 Korea National Health and Nutrition Examination Survey (KNHANES). Low muscle mass was defined as the value of ASM divided by height squared (ASM/height(2)) that was less than two standard deviations (SD) below the sex-specific mean of the young reference group.

RESULTS

Forced expiratory volume in 1 s (FEV1[L]) and forced vital capacity (FVC[L]) were positively correlated with ASM/height(2) in males (p < 0.001 and p = 0.001, respectively) but not in females (p = 0.360 and p = 0.779, respectively). A univariate logistic regression analysis revealed that males with low FEV1 or FVC were more likely to have low muscle mass (odds ratio [OR] = 3.11, 95% confidence interval [CI] 1.62-5.99 for FEV1; OR = 1.99, 95% CI 1.13-3.53 for FVC); similar results were found for females, but the significance was lower (OR = 11.37, 95% CI 0.97-132.91 for FEV1; OR = 7.31, 95% CI 1.25-42.74 for FVC). After adjusting for age, smoking, and moderate physical activity, a low FEV1 value was associated with low muscle mass in both males (OR = 2.90, 95% CI 1.50-5.63) and females (OR = 9.15, 95% CI 1.53-54.77).

CONCLUSIONS

Using nationally representative data from the 2008-2011 KNHANES, low pulmonary function was found to be associated with low muscle mass in community-dwelling older Korean adults.

The Added Prognostic Value of Preoperative Dynamic Contrast-Enhanced MRI Histogram Analysis in Patients with Glioblastoma: Analysis of Overall and Progression-Free Survival

BACKGROUND AND PURPOSE

The prognostic value of dynamic contrast-enhanced MR imaging in patients with glioblastoma is controversial. We investigated the added prognostic value of dynamic contrast-enhanced MR imaging to clinical parameters and molecular biomarkers in patients with glioblastoma by using histogram analysis.

MATERIALS AND METHODS

This retrospective study consisted of 61 patients who underwent preoperative dynamic contrast-enhanced MR imaging for glioblastoma. The histogram parameters of dynamic contrast-enhanced MR imaging, including volume transfer constant, extravascular extracellular volume fraction, and plasma volume fraction, were calculated from entire enhancing tumors. Univariate analyses for overall survival and progression-free survival were performed with preoperative clinical and dynamic contrast-enhanced MR imaging parameters and postoperative molecular biomarkers. Multivariate Cox regression was performed to build pre- and postoperative models for overall survival and progression-free survival. The performance of models was assessed by calculating the Harrell concordance index.

RESULTS

In univariate analysis, patients with higher volume transfer constant and extravascular extracellular volume fraction values showed worse overall survival and progression-free survival, whereas plasma volume fraction showed no significant correlation. In multivariate analyses for overall survival, the fifth percentile value of volume transfer constant and kurtosis of extravascular extracellular volume fraction were independently prognostic in the preoperative model, and kurtosis of volume transfer constant and extravascular extracellular volume fraction were independently prognostic in the postoperative model. For progression-free survival, independent prognostic factors were minimum and fifth percentile values of volume transfer constant and kurtosis of extravascular extracellular volume fraction in the preoperative model and kurtosis of extravascular extracellular volume fraction in the postoperative model. The performance of preoperative models for progression-free survival was significantly improved when minimum or fifth percentile values of volume transfer constant and kurtosis of extravascular extracellular volume fraction were added.

CONCLUSIONS

Higher volume transfer constant and extravascular extracellular volume fraction values are associated with worse prognosis, and dynamic contrast-enhanced MR imaging may have added prognostic value in combination with preoperative clinical parameters, especially in predicting progression-free survival.

Pilot study on interfractional and intrafractional movements using surface infrared markers and EPID for patients with rectal cancer treated in the prone position

OBJECTIVE

To evaluate interfractional and intrafractional movement of patients with rectal cancer during radiotherapy with electronic portal imaging device (EPID) and surface infrared (IR) markers.

METHODS

20 patients undergoing radiotherapy for rectal cancer with body mass index ranging from 18.5 to 30 were enrolled. Patients were placed in the prone position on a couch with a leg pillow. Three IR markers were put on the surface of each patient and traced by two stereo cameras during radiotherapy on a twice-weekly basis. Interfractional isocentre movement was obtained with EPID images on a weekly basis. Movement of the IR markers was analysed in correlation with the isocentre movement obtained from the EPID images.

RESULTS

The maximum right-to-left (R-L) movement of the laterally located markers in the horizontal isocentre plane was correlated with isocentre translocation with statistical significance (p = 0.018 and 0.015, respectively). Movement of the surface markers was cyclical. For centrally located markers, the 95% confidence intervals for the average amplitude in the R-L, cranial-to-caudal (C-C) and anterior-to-posterior (A-P) directions were 0.86, 2.25 and 3.48 mm, respectively. In 10 patients, intrafractional movement exceeding 5 mm in at least one direction was observed. Time-dependent systematic movement of surface markers during treatment, which consisted of continuous movement towards the cranial direction and a sail back motion in the A-P direction, was also observed.

CONCLUSION

Intrafractional movement of surface markers has both cyclic components and time-dependent systematic components. Marker deviations exceeding 5 mm were mainly seen in the A-P direction. Pre- or post-treatment EPID images may not provide adequate information regarding intrafractional movement because of systematic movement in the A-P direction during radiotherapy.

ADVANCES IN KNOWLEDGE

This work uncovered a sail back motion of patients in the A-P direction during radiotherapy. Pre- or post-treatment EPID images may not provide accurate positioning of patients in the A-P direction because of this time-dependent intrafractional motion.

Crosstalk analysis in homogeneous multi-core two-mode fiber under bent condition

We analyze the inter-core crosstalk in homogeneous multi-core two-mode fibers (MC-TMFs) under bent condition by using the coupled-mode equations. In particular, we investigate the effects of the intra-core mode coupling on the inter-core crosstalk for two different types of MC-TMFs at various bending radii. The results show that the inter-core homo-mode crosstalk of LP(11) mode is dominant under the gentle fiber bending condition due to its large effective area. However, as the fiber bending becomes tight, the intra-core mode coupling is significantly enhanced and consequently makes all the inter-core crosstalk levels comparable to each other regardless of the mode. A similar tendency is observed at a reduced bending radius when the difference in the propagation constants between modes is large and core pitch is small.

Role of second-look ultrasound examinations for MR-detected lesions in patients with breast cancer

PURPOSE

To assess the clinical value of second-look ultrasound (US) examination for the evaluation of additional enhancing lesions detected on magnetic resonance (MR) imaging.

MATERIALS AND METHODS

Between May 2008 and February 2011, 794 consecutive patients with histologically confirmed breast cancer underwent breast MR imaging. We included 101 patients with 132 additional enhancing breast lesions detected on MR imaging who underwent second-look US.  The imaging features and lesion category according to the Breast Imaging and Reporting and Data System (BI-RADS) were assessed with MR and US imaging, respectively.

RESULTS

According to the BI-RADS system, 67 lesions (50.8 %) were classified as category 0, 33 lesions (25.0 %) as category 3, and 32 lesions (24.2 %) as category 4. Of the 67 indeterminate lesions on MR imaging, 34 (50.7 %) were demonstrated on second-look US. 11 of these 34 lesions showed suspicious sonographic features, including 1 lesion that showed malignancy (9.1 %, 1/11). Most of the suspicious lesions on MR imaging (26 of 32 BI-RADS category 4 lesions, 81.3 %) were demonstrated on second-look US, and 17 were malignant (65.4 %, 17/26). Of the 6 BI-RADS category 4 lesions without sonographic correlation, 1 was malignant (16.7 %, 1/6).

CONCLUSION

Second-look US examination was useful for evaluating MR-detected lesions in patients with breast cancer.

UV Light and Gas Sensing Properties of Hybrid Sensor Based on Indium-Tin-Oxide Nanocrystals

We proposed a hybrid sensor which is able to detect both UV light and gas species. The sensor was fabricated by screen printing using indium-tin-oxide (ITO) nanocrystals. To improve the UV sensitivity, high temperature annealing (600 degrees C) under an external pressure (0.2 MPa) was applied. We could observe room temperature operation of the sensor under the simultaneous stimulation of UV light and CH4 gas. This is indicating that an improved fire warning is possible by using the proposed hybrid sensor.

Optical performance monitoring technique using software-based synchronous amplitude histograms

We propose and demonstrate a simple technique to monitor both the optical signal-to-noise ratio (OSNR) and chromatic dispersion (CD) by using the software-based synchronous amplitude histogram (SAH) analysis. We exploit the software-based synchronization technique to construct SAHs from the asynchronously sampled intensities of the signal. The use of SAHs facilitates the accurate extraction of the monitoring parameters at the center of the symbol. Thus, unlike in the case of using the technique based on the asynchronous amplitude histogram (AAH), this technique is not affected by the transient characteristics of the modulated signals. The performance of the proposed monitoring technique is evaluated experimentally by using 10-Gbaud quadrature phase-shift keying (QPSK) and quadrature amplitude modulation (QAM) signals over wide ranges of OSNR and CD. We also evaluate the robustness of the proposed technique to the signal's transient characteristics.

Gender flip-flop association between genetic variations of NEDD4L and metabolic syndrome in the Kazakh general population

Genetic variation is thought to contribute to etiology of metabolic syndrome (MS). Neural precursor cell expressed developmentally downregulated 4-like gene (NEDD4L) is a candidate gene for MS. This study investigated the relationship between variations of NEDD4L and MS in the Kazakh, which is an ideal population to study the genetic mechanisms of complex diseases such as MS. We screened the promoter and exons of NEDD4L in 48 Kazakh individuals with MS to identify representative variations. By genotyping the representative variations [271420T>C (rs2288774), 271454A>G (rs2288775), and 296921-296923delTTG] in the Kazakh general population, we conducted a case-control study. In female subjects, the distribution of genotypes and alleles of rs2288775 and 296921-296923delTTG differed significantly between the MS pacients and controls. In male subjects, the genotype distributions of 296921-296923delTTG were significantly different between the MS pacients and controls in the dominant model (P = 0.047). After adjustment for age, smoking, and drinking, multivariate logistic regression analysis showed that rs2288775 was significantly associated with MS [for the A/A genotype, odds ratio (OR) = 3.296, P = 0.011] in female subjects. For 296921-296923delTTG, the I/D+D/D genotype was the high-risk genotype for MS in female subjects (OR = 2.791, P = 0.035) and was a protective factor for MS in male subjects (OR = 0.580, P = 0.045). The 296921-296923delTTG variation of NEDD4L is a gender flip-flop associated with MS in Kazakh individuals. The A allele of rs2288775 may be an independent risk factor for MS in Kazakh women. The results suggest that the genetic variations of NEDD4L might be involved in the pathogenesis of MS.

Achievable capacity improvement by using multi-level modulation format in trench-assisted multi-core fiber system

We evaluate the impacts of using multi-level modulation formats on the transmission capacity of the multi-core fiber (MCF) having trench-assisted index profile and hexagonal layout. For this evaluation, we utilize the spectral efficiency per unit area, defined as the spatial spectral efficiency (SSE). The results show that the SSE improvement achievable by using the higher-level modulation format can be reduced due to its lower tolerance to the inter-core crosstalk. We also evaluate the effects of using large effective area on the transmission capacity of the trench-assisted MCF. The results show that the use of large effective area can decrease this capacity due to the increased inter-core crosstalk and lengthened cable cutoff wavelength, although it can help increase the transmission distance. Thus, it is necessary to optimize the effective area of MCF by considering both the SSE and transmission distance. However, the results indicate that the effect of using different effective areas on the SSE-distance product is not significant, and it is not useful to increase the effective area of the trench-assisted MCF to be larger than ~110 μm(2).

Factors associated with early onset post-traumatic syringomyelia

STUDY DESIGN

Retrospective study.

OBJECTIVES

To identify factors associated with the development of early onset post-traumatic syringomyelia within 5 years of spinal cord injury.

SETTING

Department of Rehabilitation Medicine, Pusan National University School of Medicine, Korea.

METHODS

We retrospectively examined the records of 502 patients with traumatic cervical or thoracic spinal cord injury who underwent follow-up magnetic resonance imaging (MRI) examinations more than once a year for at least 5 years. Patients were assessed in terms of the neurological level of injury, the severity of initial spinal cord injury, the use of surgery and the extent of spinal canal involvement. The latter was evaluated by calculating the shortest antero-posterior diameter of the injured vertebral canal and the spinal reserve capacity as shown on MRI at the time of trauma onset and at the time of diagnosis of syringomyelia.

RESULTS

Syringomyelia developed within 5 years in 37 (7.3%) of the 502 patients. The mean age of these 37 patients was 44.6 years (range, 17-67 years) and the mean interval from spinal cord injury to onset of syringomyelia was 38.8 months (range, 2-54 months). The development of post-traumatic syringomyelia within 5 years was not significantly related to the severity or level of injury, the use of spinal surgery or the extent of spinal canal encroachment (P≥0.05 for each comparison).

CONCLUSION

Early onset syringomyelia occurring within 5 years after spinal cord injury was not associated with neurological injury level, severity of injury, the use of spinal surgery or canal encroachment.

Metastatic sarcomatoid carcinoma to liver and bone marrow in renal transplant recipient: due to exacerbation of quiescent renal cancer? A case report

Sarcomatoid carcinoma is a rare tumor with rapid growth and a poor prognosis. A 60-year-old man underwent kidney transplantation. Three months after transplantation, multiple tumors were found in the liver and bone, and the patient died several days later. Pathological examination of liver and bone marrow biopsies revealed metastatic sarcomatoid carcinoma. Pretransplantation, the patient's workup was positive only for mild thrombocytopenia and a complicated cyst with peripheral rim calcification (Bosniak IIF) in the right kidney. Retrospectively, we found the abdominal computed tomography film, which had been examined at another hospital 6 years previously. The calcified complicated cyst was a 3-cm enhancing solid mass in the right kidney, suggesting renal cell cancer. It is possible that the cancer developed from the calcified complicated cyst. In this case, immunosuppressants may have altered malignant cell proliferation, invasion, and the form of metastasis.

An immunohistochemical study of the pancreatic endocrine cells of the Korean golden frog, Rana plancyi chosenica

The regional distribution and quantitative frequency of pancreatic endocrine cells were demonstrated in the Korean golden frog (Rana plancyi chosenica Okada), which is known as a Korean endemic species, for the first time by immunohistochemical methods using specific mammalian antisera to insulin, glucagon, somatostatin and human pancreatic polypeptide (PP). In the pancreas of the Korean golden frog, all four endocrine cell types were demonstrated. Insulin- and glucagon-positive cells were located in the pancreas as single cells or islet-like clusters, respectively. Somatostatin-containing cells were also dispersed in the pancreas as single cells or clusters but in the case of clusters, they are exclusively situated in the marginal regions of insulin- or glucagon-positive cell clusters. PP-containing cells were also distributed as single cells or clusters. Clusters consisted of PP-positive cells are distributed as a core type and a marginally distributed type. Overall, there were 40.84±3.81% insulin-, 26.02±1.71% glucagon-, 7.63±2.09% somatostatin- and 25.51±3.26% PP-IR cells.

Electrochemical isothermal-capacitance-transient spectroscopy: a new depth profiling method of deep levels

The authors report on a new depth profiling method of deep levels, which we call electrochemical isothermal-capacitance-transient spectroscopy (EICTS). This is combined with electrochemical capacitance-voltage using the Schottky barrier of etchable electrolyte and isothermal-capacitance-transient spectroscopy using the capacitance-transient profile at a fixed temperature. We proved its validity by applying to the ZnSe:N epitaxial film of thickness of more than 1000 nm and comparing the characteristics of an obtained deep level with the results measured by conventional deep-level detection techniques. It is expected that EICTS is very effective to assess the deep levels of wide-bandgap semiconductors that suffer from various point defects and their complexes.

Clinical outcomes and prognostic factors in patients with tuberculous destroyed lung

OBJECTIVE

To characterise the prognosis and identify factors contributing to mortality in patients with tuberculous destroyed lung (TDL).

DESIGN

Following a retrospective review of clinical data and radiographic findings, 169 patients with TDL were enrolled in this study. All patients were graded on a 4-point scale (field score 1-4) based on the extent of destroyed lung parenchyma on chest radiography.

RESULTS

The mean patient age was 64 years (range 33-90); 103 (61%) were male. The median number of hospitalisations was 1 (range 0-11) during follow-up, with a mean duration of 31 months (range 0-172). Pneumonia developed in 96 patients (57%), while 50 patients (30%) developed acute respiratory failure requiring mechanical ventilation, 37 (22%) haemoptysis, 24 (14%) spontaneous pneumothorax and 22 (13%) reactivation of tuberculosis. Overall mortality was 28% (47/169), with a median survival of 39 months (range 0-176) after diagnosis. TDL-related mortality was 19% (32/169), and a field score ≥ 3 was the only independent predictor of shorter survival based on a Cox proportional hazards model (HR 3.520, 95%CI 1.51-8.20, P = 0.004).

CONCLUSION

TDL has a poor prognosis, particularly in patients with more extensive lung destruction.

Limitations in fields of vision for simulated young farm tractor operators

Farm tractors account for the majority of deaths and injuries among youths working on North American farms. A vehicle operator's field of vision is an important operational aspect for safe driving. However, very little is known about visual limitations of young tractor operators compared to adult operators. The main purpose of this study was to quantify limitations in fields of vision of children with different anthropometry. The study was based on assessment of 42 farm tractors in popular use in the USA. The results showed that youth operators typically had diminished fields of vision compared to the average adult operator. The degree of visual limitation is greatest for objects at close distances and when objects are straight in front of the operator/tractor. This has serious implications in terms of risks for runovers, rollovers and collisions. Study findings may help illuminate the development of policies and guidelines in tractor-related jobs for children. STATEMENT OF RELEVANCE: This study provides an ergonomic approach for evaluation of children's visual limitations in tractor operations. This approach could be used in other related cases, where children are allowed to operate vehicles.