Survival and renal outcomes of direct heart transplant from veno-arterial extracorporeal membrane oxygenation support

Backgrounds

Patients on veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support are given the highest priority for cardiac transplantation (OHT) in the new UNOS heart allocation policy adopted in October 2018. Although patients may receive an organ quicker there may not be enough time to recover end-organ function. To date, little is known about survival and renal outcomes of direct OHT in patients that have been supported with VA-ECMO as a bridge to transplant due to limited experience in most transplant centers.

Purpose

The aim of this study was to investigate survival and renal outcomes of direct OHT in patients supported with VA-ECMO prior to transplant.

Methods

From January 2010 to February 2022, 23 patients who received single organ OHT alone directly from VA-ECMO support were retrospectively analyzed (16 patients after the new allocation policy). Kaplan-Meier analysis was used to estimate event-free survival.

Results

The median age of recipients was 48 years. The median length of pre-transplant VA-ECMO support was 5 days. Additional pre-transplant support with intra-aortic balloon pump or Impella was utilized in 15 patients (65.2%) and 2 patients (9%) respectively. There was a trend toward improvement of serum creatinine after initiation of VA-ECMO support (Pre-ECMO: 1.66±1.22 mg/dl vs. Pre-OHT: 1.20±0.74 mg/dl, P=0.084). Four patients required preoperative renal replacement therapy (RRT); three were on RRT at the time of OHT. The median ischemic time of donor hearts was 168 minutes. VA-ECMO support was continued in 10 patients (43.5%) after OHT.

Hospital mortality was 8.7% (2 patients). Post-transplant RRT was required in 9 patients (39.1%), and, of these, 5 patients were transitioned to permanent dialysis. Among the 14 patients who did not require post-transplant RRT, none required RRT during the follow-up period (median, 21.5 months). Kaplan-Meier survival analysis showed that estimated survival at 1 year and 3 years were 86.1%, and 77.5%, respectively (Figure 1A). The freedom from dialysis rate was 82.4% at 1 year, and 74.9% at 3 years (Figure 2A). Both survival (100% vs. 66.7%, P=0.008, Fig.1B) and dialysis free rate (100% vs. 55.6%, P=0.002, Figure 2B) at one-year were significantly worse in patients who required postoperative RRT.

Conclusions

To our knowledge this is the largest single center study of OHT in patients that were supported with VA-ECMO. VA-ECMO as a bridge to end-organ recovery and OHT resulted in excellent outcomes. Patients who required post-transplant RRT more likely to require long-term dialysis, while those that did not receive RRT showed favorable outcomes. Overall survival in this patient population is comparable to patients that were not on VA-ECMO prior to transplant.

Funding Acknowledgement

Type of funding sources: None.

P01.07.A Neurocognitive outcomes after proton beam therapy for skull base tumours

Background

Evidence suggests that Proton Beam Therapy (PBT) may lessen the risk of neurocognitive decline (NCD) by reducing the dose to the normal brain as compared to conventional photon radiotherapy (XRT). We report the incidence of moderate-severe (Grade ≥3) NCD in adults treated for skull base chordomas and chondrosarcomas within the United Kingdom’s Proton Overseas Programme (POP).

Material and Methods

Baseline (pre-PBT) and follow-up clinical outcomes data were prospectively collected as part of a national PBT-outcomes registry, which started in 2008 . This registry is curated by a dedicated Proton Clinical Outcomes Unit. Specifically, late toxicities ≥G3 as per CTCAE (Common Terminology Criteria for Adverse Events) v4.0 definition, occurring later than 90 days after treatment completion, were recorded. This study focuses on the incidence of memory impairment (MI) in the adult (≥25 y) cohort.

Results

Between 2008-2018, 141 adult patients were treated for skull base chordomas (77 patients, 54.6%) and chondrosarcomas (64 patients, 45.4%) via the POP (the majority -62.8%- treated at the University of Florida PBT Institute). Median age at treatment was 51 years (range 26-77). Median prescription dose was 73.8 GyRBE (70-75.6), with a median dose per fraction of 1.8 Gy (1.2-2.1). Of note, the median dose for chondrosarcomas was 70.2 GyRBE (70-75.6), whereas the median dose for chordomas was 73.8 GyRBE (72-75.6). Median follow up was 39 months (0-138). On clinical assessment, 4 patients (2 chordomas, 2 chondrosarcomas) were reported with G3 MI after a median time of 43 months (27-49). None of them had impaired memory at baseline, nor relevant neurological comorbidities. Median age of those who developed G3 MI was 63 y (39-70). Median prescription dose was 72.9 GyRBE (70-73.8). Plans were available for 3 of these 4 patients. Relevant dose statistics to hippocampi and temporal lobes were extracted. Dmean to the omo- and contralateral hippocampi in these 3 patient plans were: patient 1) 33.7 and 11.6 GyRBE; patient 2) 28.1 and 24.4 Gy; patient 3) 8.7 and 8.2 GyRBE, respectively. V20 to the omo- and contralateral temporal lobes in the same patients were: patient 1) 47% and 10%; patient 2) 29% and 28.7%; patient 3) 30% and 28%, respectively. Suggested constraints for these structures are: Dmean < 20 Gy to the hippocampi and V20Gy <10% to the temporal lobes.

Conclusion

Our results indicate that adult patients undergoing high dose radiation for radioresistant tumours may experience detrimental effects on memory. Neurocognitive baseline and follow-up assessment is not routinely performed in this age group but might be appropriate to explore which domains of cognitive function are mainly affected. Larger cohorts are warranted to establish predictive factors and better understand dose volume effect of brain structures and neurocognitive sequelae.

Effect of Weight-Adjusted Phenylephrine, Norepinephrine, and Metaraminol for Elective Cesarean Delivery on Neonatal Acid–Base Status: A Randomized Controlled Trial

Purpose

Many previous trials have compared the effects of different vasoactive drugs on cesarean section patients, but their infusion rate is based on experience rather than high-quality evidence. It is difficult to judge whether the effect of vasoactive drug comes from the better choice or a more appropriate at rates of vasoactive drugs. The effect of vasoactive drugs at the rates of the 90% effective dose needs to be verified and compared.

Patients and Methods

Women undergoing elective caesarean delivery under combined spinal-epidural anaesthesia were randomized to receive phenylephrine or norepinephrine or metaraminol infusion at the rate that was assumed to be the 90% effective dose. Anesthetic management was standardized and included fluid loading with 10 mL/kg of Ringer. The primary outcome was the umbilical artery pH.

Results

78 patients were included. The umbilical artery pH was not significantly different among the three groups (phenylephrine group: 7.33 ± 0.03 vs norepinephrine group: 7.33 ± 0.04 vs metaraminol group: 7.33 ± 0.04, P = 0.99). There were no significant differences in the incidence of hypotension, hypertension, bradycardia, and nausea and vomiting among the three groups. The SBP of the phenylephrine group was significantly higher than that of the metaraminol group (adjustive P value = 0.005).

Conclusion

Phenylephrine (0.54 μg/kg/min) or metaraminol (2 μg/kg/min) or norepinephrine (0.08 μg/kg/min) administered to healthy patients with elective cesarean section after spinal anesthesia has no significant effect on the acid-base balance of the fetus.

Comparison of Analgesic Efficacy of Local Anesthetic Infiltration and Ultrasound-guided Abdominal Wall Nerve Block in Children Undergoing Ambulatory Inguinal Hernia Repair

PURPOSE

Placement of local anesthetics either as infiltration (LAI) or as abdominal wall nerve block (AWNB) has been shown to reduce postoperative pain following laparoscopic surgery. We aimed to compare intraoperative remifentanil consumption and postoperative pain of AWNB and LAI in children undergoing ambulatory two-port laparoscopic inguinal hernia surgery with propofol-remifentanil based general anesthesia.

DESIGN

Randomized controlled trial.

METHODS

Children aged between 1 and 6 years undergoing two-port laparoscopic inguinal hernia repair were enrolled for analysis. These children received one of the three anesthesia regimens (1) standard general anesthesia (SGA); (2) SGA with preemptive LAI; (3) SGA with preemptive AWNB; and were categorized accordingly. Primary outcome variable were intraoperative average infusion rate of remifentanil and postoperative FLACC (Face, Legs, Activity, Cry, and Consolability) pain score. Secondary outcome data included demographics, intraoperative variables (hemodynamics and bispectral index score recorded at three different time points), and duration of surgery.

FINDINGS

A total of 90 children (30 in each group) were included in the analysis. General information, intraoperative hemodynamic variables, bispectral index score, and duration of surgery were not significantly different among groups. The intragroup variation of hemodynamic variables were less stable in the SGA group compared with the other two groups, while BIS score was similar among groups. The intraoperative infusion rate of remifentanil was significantly lower in the AWNB group than in the SGA or the LAI group (median [25th to 75th centiles]: 0.11[0.11 to 0.11] µg/kg/min, 0.33[0.33 to 0.33] µg/kg/min; 0.17[0.17 to 0.20] µg/kg/min, respectively, P < .001 for both), and lower in the LAI group than in the SGA group (P < .001). The postoperative FLACC pain score was significantly lower in the AWNB group than in the SGA or the LAI group (P < .001 for both).

CONCLUSIONS

AWNB is associated with a lower intraoperative remifentanil requirement and a lower postoperative FLACC pain score compared with LAI in children undergoing laparoscopic inguinal hernia repair with propofol-remifentanil based general anesthesia.

[Value of purple sign for predicting rebleeding events in cirrhotic patients following endoscopic selective varices devascularization]

OBJECTIVE

To assess the value of the purple sign for predicting long-term rebleeding events in cirrhotic patients following endoscopic selective varices devascularization.

METHODS

We retrospectively analyzed the clinical data of 97 patients with liver cirrhosis, who had a history of gastroesophageal variceal bleeding and underwent endoscopic selective varices devascularization. Thirty-two of the patients showed purple sign after endoscopic treatment. We used propensity score matching (PSM) to minimize the selection bias of the patients (purple sign vs no purple sign) and reduce the intergroup differences of clinical characteristics. The primary outcome measure of this study was cumulative rebleeding events after endoscopic selective varices devascularization.

RESULTS

The 1-year rebleeding rate (27.0% vs 36.7%) or 6-month rebleeding rate (10.9% vs 26.9%) following endoscopic treatment was not significantly different between the purple sign group and no purple sign group before PSM (P=0.2385). But after PSM, the 1-year rebleeding rate (28.2% vs 56.4%) and 6-month rebleeding rate (5.0% vs 37.0%) were significantly lower in the purple sign group than in the no purple sign group (P=0.0304).

CONCLUSIONS

The presence of purple sign indicates a lower risk of rebleeding after endoscopic treatment of cirrhotic gastroesophageal varices and a potentially favorable treatment response after endoscopic therapy, thus providing a clinical indicator for stratification of the patients for sequential endoscopic sessions.

The Accuracy of a Wireless Axillary Thermometer for Core Temperature Monitoring in Pediatric Patients Having Noncardiac Surgery: An Observational Study

PURPOSE

A wireless and wearable axillary thermometer (iThermonitor) has been validated for perioperative core temperature monitoring in adults. The purpose of this study was to evaluate its accuracy in pediatrics having non-cardiac surgery.

DESIGN

Prospective observational study.

METHODS

From January 2019 to December 2019, 70 children aged younger than 14 years undergoing surgery in a tertiary hospital were selected. Pairs of esophageal temperatures (T_Eso), rectal temperatures (T_Rec), and axillary temperatures monitored by the iThermonitor (T_iTh) were collected every 5 min during surgery. Taking T_Eso as reference, the bias between T_Eso and T_iTh and the proportion of bias within ±0.5°C were calculated. Bland-Altman method was used to analyze the 95% of limits of agreement (LOA) between T_iTh and T_Eso. The same analyses were done for T_Rec. FINDINGS: A total of 2232 pairs of temperatures were collected. The bias (mean ± SD) between T_iTh and T_Eso was -0.07 °C ± 0.25°C, and 95% LOA was -0.07°C ± 0.50°C. The proportion of bias within ±0.5°C accounted for 96% (95% Confidence Interval [CI], 92-98%). Higher bias and 95% LOA, and lower proportion of bias within ± 0.5°C were found between T_Rec and T_Eso than those between T_iTh and T_Eso.

CONCLUSION

During pediatric non-cardiac surgery, axillary temperature derived from iThermonitor is in good agreement with esophageal temperature and can be used as an alternative to core temperature.

Comparative immunogenicity of outer membrane protein K and whole-cell antigens of Vibrio parahaemolyticus for diagnosis

The immunogenicity of soluble outer membrane protein K (OmpK)- small ubiquitin-like modifier, OmpK inclusion bodies, formalin, and heat-killed Vibrio parahaemolyticus cells were prepared and studied in a mouse model. The results of whole-cell ELISA and Western blot (WB) revealed that the serum against soluble OmpK and OmpK inclusion bodies reacted only with homologous V. parahaemolyticus. Furthermore, recombinant OmpK proteins were not recognized by the serum against whole-cell V. parahaemolyticus antigens. Unexpectedly, the serum against formalin and heat-killed V. parahaemolyticus reacted broadly with homologous (an immunization strain) and heterologous (non-immunization strains) V. parahaemolyticus and Vibrio species. The WB results revealed that the serum against the two V. parahaemolyticus whole-cell antigens primarily reacted with proteins that were approximately 100, 70, 36, 28, and 22 kDa in the cell lysates from different Vibrio strains, rather than the recombinant OmpK. The 70 and 28 kDa proteins exhibited specificity to Vibrio species, while the 22 kDa protein was more specific to V. parahaemolyticus. This study showed the limitation of recombinant OmpK to prepare diagnostic antibodies and revealed several specific Omps of Vibrio sp. and V. parahaemolyticus that were promising in diagnosis and vaccine development.

Three-dimensional vectorcardiographic characteristics of breast cancer patients treated with chemotherapy

Funding Acknowledgements

Type of funding sources: None.

Background

 Patients receiving chemotherapy for breast cancer (BC) may develop cardiac electrophysiological abnormalities. The aim of this study is to examined possible alterations in cardiac electrophysiological parameters detected by three-dimensional vectorcardiograms (3D-VCGs) in BC patients who received chemotherapy.

Methods

This was a prospective single-center cohort study conducted. Patients with BC referred for chemotherapy from May 1, 2019, to October 1, 2019 were invited to participate in the study. 3D-VCG and echocardiography were recorded at rest four times (baseline, after the first cycle, after third cycles and at the end of the regimen, respectively). 

Results

 A total of 63 patients were included. Compared with baseline, decreases in 3-dimensional maximum T vector magnitude (TVM) (0.29 ± 0.10 vs. 0.25 ± 0.10mV; p &lt; 0.05) and 3-dimensional T/QRS ratio (0.26 ± 0.11 vs. 0.21 ± 0.11; p &lt; 0.05) were observed by the end of chemotherapy regimen, while echocardiographic parameters showed no significant variation before and after chemotherapy (all P &gt; 0.05). Maximum TVM showed a significant positive correlation with left ventricular ejection fraction (LVEF) (all p &lt; 0.05). Furthermore, the cut-off value with 0.23 of 3-dimensional T/QRS ratio (the area under the curve [AUC] 0.725) for differentiating LVEF reduction ≥10% following initiation of chemotherapy. The AUC of the front plane T/QRS ratio and horizontal plane T/QRS ratio for the detection of an LVEF reduction ≥10% was 0.725 and 0.763, respectively.

Conclusions

 3D-VCGs can be used to detect electrophysiological abnormalities in BC patients receiving chemotherapy. Subclinical cardiac dysfunction can be revealed by 3D-VCGs before alterations in traditional echocardiographic parameters.

The acquisition of Mycobacterium tuberculosis infection in village doctors in China: a prospective study

BACKGROUND: Occupational exposure-related risk of Mycobacterium tuberculosis infection has been reported for village doctors in China. This prospective study aims to estimate the infection acquisition in this key population.METHODS: At baseline, all village doctors registered in Zhongmu County were tested by QuantiFERON^®-TB Gold In-Tube (QFT) and QuantiFERON^®-TB Gold Plus (QFT-Plus) in parallel. Those negatives for either of the tests were retested to identify conversions at the 2-year follow-up investigation.RESULTS: A total of 367 eligible participants completed the 2-year follow-up survey with frequency of conversion of 5.0% (18/361) for QFT and 6.1% (21/343) for QFT-Plus. The agreement of follow-up results between the tests was 93.2% with a κ coefficient of 0.43 (95%CI 0.20-0.65). Among QFT-Plus convertors, the difference between TB1 and TB2 tubes (TB2-TB1) was significantly increased as compared with baseline results (P = 0.039). Participants from the villages with occurrence of microbiologically confirmed pulmonary TB showed higher frequency of QFT conversions (11.0% vs. 3.2%, P = 0.011) and QFT-Plus conversions (12.3% vs. 4.4%, P = 0.027) than those from the villages without occurrence.CONCLUSION: Our results consistently suggest that capability on occupational protection and M. tuberculosis infection control should be improved in village doctors in China.

Large-for-gestational age diagnosed during second-trimester anatomy ultrasound and association with gestational diabetes and large-for-gestational age at birth

OBJECTIVES

To determine if large-for-gestational age (LGA) diagnosed during second-trimester ultrasound examination is associated with the development of gestational diabetes mellitus (GDM) and LGA at birth.

METHODS

This was a retrospective cohort study of all pregnant women who underwent a second-trimester anatomy ultrasound examination between 18 and 22 weeks at our institution from 2012 to 2017. Patients were included in the LGA group if estimated fetal weight and/or fetal abdominal circumference was ≥ 90^th percentile for gestational age. Patients with a history of pre-GDM, multiple gestation, preterm delivery, use of betamethasone or fetal anomaly were excluded. The control group consisted of appropriate-for-gestational-age (AGA) pregnancies that were scanned at 18-22 weeks during the study period. AGA was defined as EFW > 10^th percentile and ≤ 89^th percentile. Prenatal and delivery records were reviewed and demographic and outcome variables were collected. Multivariable logistic regression models were applied to assess the impact of LGA diagnosed in the second trimester on the development of GDM and LGA at birth (birth weight ≥ 90^th percentile).

RESULTS

The study population included 756 patients with a LGA fetus and 756 with an AGA fetus on second-trimester ultrasound examination. In patients with a LGA fetus diagnosed during the second-trimester ultrasound examination, the incidence of GDM was 6.0% and the incidence of LGA at birth was 14.9%. Among patients with a LGA fetus in the second trimester, those who developed GDM or LGA at birth were significantly older and were more likely to be obese. Moreover, parity was associated with neonatal LGA (P = 0.0003) but not with GDM (P = 0.82). On multivariable logistic regression analysis with adjustment for age, parity, change in gestational body mass index, obesity, ethnicity and neonatal sex, LGA diagnosed during the second trimester was associated significantly with GDM (adjusted odds ratio (aOR), 2.54; 95% CI, 1.29-5.03; P = 0.007) and LGA at birth (aOR, 6.85; 95% CI, 3.60-13.05; P < 0.0001).

CONCLUSIONS

LGA diagnosed during second-trimester ultrasound examination is associated with the development of GDM and LGA at birth, independent of known risk factors, and could be used to identify these women earlier for intervention. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Effects of Local Warming on the Peripheral Vein Cross-Sectional Area in Children Under Sedation

PURPOSE

Peripheral venous catheterization is challenging in small children. The local warming technique has been used to increase the peripheral vein cross-sectional area (CSA) and improve the success rate. However, there is limited evidence on the effect of local warming on venous CSA in children under sedation.

DESIGN

A pilot randomized controlled trial.

METHODS

Eligible children aged 1 to 4 years undergoing ambulatory surgery were enrolled. At the bedside in the ambulatory surgery center, they were routinely sedated with 1 mcg/kg of intranasal dexmedetomidine. Through a computer allocation program, children were randomized into either a control group or a local warming group. Cephalic vein and basilic vein at 1 cm proximal to cubital fossa were scanned with ultrasound to measure venous CSA. Children in the control group received no intervention; those in the local warming group had a prepared hot pack of ~40°C applied to the target area on the arm for 5 minutes. A second ultrasound measurement was undertaken in both groups.

FINDINGS

A total of 35 from 40 children were analyzed. Cephalic vein CSA and basilic vein CSA increased significantly vs the first measurement within the local warming group (P < .05 for both) but not in the control group (P > .05 for both). Cephalic vein CSA was significantly different between groups at the second measurement (P < .05) but not at the first measurement (P > .05). Basilic vein CSA was significantly different between groups neither at the first measurement nor at the second measurement (P > .05 for both). The application of local warming resulted in an average of 34% increase (from 4.1 to 5.5 mm²) in cephalic vein CSA and an average of 21% increase (from 4.8 to 5.8 mm²) in basilic vein CSA.

CONCLUSIONS

The application of local warming induced mild venodilation in cephalic vein with an increase in CSA by 34% and had little venodilation effect on the basilic vein with an increase in CSA by only 21%.

Identification of novel monoclonal antibodies targeting the outer membrane protein C and lipopolysaccharides for Escherichia coli O157:H7 detection

AIMS

To identify and evaluate the application of two novel monoclonal antibody (mAb) 2G12 against outer membrane protein (Omp) C and mAb 12B1 targeting the O chain of the lipopolysaccharides (LPS) of Escherichia coli O157:H7 (ECO157).

METHODS AND RESULTS

The sensitivity and specificity of these two antibodies were evaluated with eight ECO157 strains and 68 untargeted strains. mAb 2G12 and 12B1 had no detectable binding with any of the non-O157 strains at 6·0 log₁₀ CFU per ml, while its high specificity and affinity remained with all ECO157 strains. When a higher level (8·0 log₁₀ CFU per ml) was tested, 2G12 and 12B1 did not react with 82·35 and 97·06% of the non-O157 strains respectively. Based on the pair of two antibodies, the sandwich enzyme-linked immunosorbent assay detected 100% (8/8) of ECO157 strains and none of the non-ECO157 strains. The detection limit of ECO157 strains in pure culture were 4·2 ± 0·2 log₁₀ CFU per ml. When the developed test was applied to artificially inoculated beef samples, the detection limit was 6·0 log₁₀ CFU per gram without enrichment and 1·0 log₁₀ CFU per gram after 12 h of enrichment.

CONCLUSIONS

The two novel antibodies identified in this study served as great candidates for the recovery, and detection of ECO157 from different environmental and food samples.

SIGNIFICANCE AND IMPACT OF THE STUDY

ECO157-specific detection was improved by a combination of the novel OmpC mAb and LPS mAb with defined target antigen and good specificity.

Prognostic value of cardiac cycle efficiency in children undergoing cardiac surgery: a prospective observational study

BACKGROUND

Cardiac cycle efficiency (CCE) derived from a pressure-recording analytical method is a unique parameter to assess haemodynamic performance from an energetic view. This study investigated changes of CCE according to an anatomical diagnosis group, and its association with early postoperative outcomes in children undergoing cardiac surgery.

METHODS

Ninety children were included with a ventricular septal defect (VSD; n=30), tetralogy of Fallot (TOF; n=40), or total anomalous pulmonary venous connection (TAPVC; n=20). CCE along with other haemodynamic parameters, was recorded from anaesthesia induction until 48 h post-surgery. Predictive CCE (CCE_p) was defined as the average of CCE at post-modified ultrafiltration and CCE at the end of surgery. The relationship between CCE and early outcomes was assessed by the comparison between the high-CCE_p group (CCE_p ≥75th centile) and the low-CCE_p group (CCE_p ≤25th centile).

RESULTS

There was a significant time × diagnostic group interaction effect in the trend of CCE. Compared with the high-CCE_p group (n=23), the low-CCE_p group (n=22) required more inotropics post-surgery, had higher lactate concentrations at 8 and 24 h post-surgery, a longer intubation time and longer ICU stay, and higher frequency of peritoneal fluid.

CONCLUSIONS

Perioperative changes of CCE vary according to anatomical diagnosis in children undergoing cardiac surgery. Children with TOF have an unfavourable trend of CCE compared with children with VSD or TAPVC. A decline in CCE is associated with adverse early postoperative outcomes.

CLINICAL TRIAL REGISTRATION

ChiCTR1800014996.

Impact of Peer Review in Reducing Uncertainty in the Definition of the Lung Target Volume Among Trainee Oncologists

AIMS

To evaluate the impact of peer review and contouring workshops on reducing uncertainty in target volume delineation for lung cancer radiotherapy.

MATERIALS AND METHODS

Data from two lung cancer target volume delineation courses were analysed. In total, 22 trainees in clinical oncology working across different UK centres attended these courses with priori experience in lung cancer radiotherapy. The courses were made up of short presentations and contouring practice sessions. The participants were divided into two groups and asked to first individually delineate (IND) and then individually peer review (IPR) the contours of another participant. The contours were discussed with an expert panel consisting of two consultant clinical oncologists and a consultant radiologist. Contours were analysed quantitatively by measuring the volume and local distance standard deviation (localSD) from the reference expert consensus contour and qualitatively through visual analysis. Feedback from the participants was obtained using a questionnaire.

RESULTS

All participants applied minor editing to the contours during IPR, leading to a non-statistically significant reduction in the mean delineated volume (IND = 140.92 cm3, IPR = 125.26 cm3, P = 0.211). The overall interobserver variation was similar, with a localSD of 0.33 cm and 0.38 cm for the IND and IPR, respectively (P = 0.848). Six participants (29%) carried out correct major changes by either including tumour or excluding healthy tissue. One participant (5%) carried out an incorrect edit by excluding parts of the tumour, while another observer failed to identify a major contour error. The participants' level of confidence in target volume delineation increased following the course and identified the discussions with the radiologist and colleagues as the most important highlights of the course.

CONCLUSION

IPR could improve target volume delineation quality among trainee oncologists by identifying most major contour errors. However, errors were also introduced after IPR, suggesting the need to further discuss major changes with a multidisciplinary team.