Background & purpose: Involved internal iliac and obturator lateral lymph nodes (LLNs) are a known risk factor for ipsi-lateral local recurrences (LLR) in rectal cancer. This study examined... Show moreBackground & purpose: Involved internal iliac and obturator lateral lymph nodes (LLNs) are a known risk factor for ipsi-lateral local recurrences (LLR) in rectal cancer. This study examined coverage of LLNs with routine radiotherapy practice in the Netherlands and associated LLR rates. Materials & methods: Patients with a primary tumor ≤8cm of the anorectal junction, cT3-4 stage and at least one internal iliac or obturator LLN with short-axis ≥5mm who received neoadjuvant (chemo)radiotherapy, were selected from a national, cross-sectional study of rectal cancer patients treated in the Netherlands in 2016. MR-images and radiotherapy treatment plans were reviewed regarding segmented LLNs as gross-tumor volume (GTV), location of LLNs within clinical target volume (CTV), and received proportion of the planned radiotherapy dose. Results: A total of 223 out of 3057 patients with at least one LLN ≥5mm were selected. Of those, 180 (80.7%) LLNs were inside the CTV, of which 60 (33.3%) were segmented as GTV. Overall, 202 LLNs (90.6%) received >95% of the planned dose. Four-year LLR rates were not significantly higher for LLNs situated outside the CTV compared to inside (4.0% vs. 12.5%, p=.092) or when receiving <95% versus >95% of the planned radiotherapy dose (7.1% vs. 11.3%, p=.843), respectively. Two of seven patients who received a dose-escalation of 60Gy developed a LLR (4-year LLR rate 28.6%). Conclusion: This evaluation of routine radiotherapy practice showed that adequate coverage of LLNs was still associated with considerable 4-year LLR rates. Techniques resulting in better local control for patients with involved LLNs need to be explored further. Show less
Kroese, T.E.; Laarhoven, H.W.M. van; Schoppman, S.F.; Deseynde, P.R.A.J.; Cutsem, E. van; Haustermans, K.; ... ; Rossum, P.S.N. van 2023
Background: Local treatment improves the outcomes for oligometastatic disease (OMD, i.e. an intermediate state between locoregional and widespread disseminated disease). However, consensus about... Show moreBackground: Local treatment improves the outcomes for oligometastatic disease (OMD, i.e. an intermediate state between locoregional and widespread disseminated disease). However, consensus about the definition, diagnosis and treatment of oligometastatic oesopha-gogastric cancer is lacking. The aim of this study was to develop a multidisciplinary European consensus statement on the definition, diagnosis and treatment of oligometastatic oesophago-gastric cancer. Methods: In total, 65 specialists in the multidisciplinary treatment for oesophagogastric cancer from 49 expert centres across 16 European countries were requested to participate in this Del-phi study. The consensus finding process consisted of a starting meeting, 2 online Delphi ques-tionnaire rounds and an online consensus meeting. Input for Delphi questionnaires consisted of (1) a systematic review on definitions of oligometastatic oesophagogastric cancer and (2) a discussion of real-life clinical cases by multidisciplinary teams. Experts were asked to score each statement on a 5-point Likert scale. The agreement was scored to be either absent/poor (<50%), fair (50%-75%) or consensus (>75%). Results: A total of 48 experts participated in the starting meeting, both Delphi rounds, and the consensus meeting (overall response rate: 71%). OMD was considered in patients with meta-static oesophagogastric cancer limited to 1 organ with <3 metastases or 1 extra-regional lymph node station (consensus). In addition, OMD was considered in patients without pro-gression at restaging after systemic therapy (consensus). For patients with synchronous or me-tachronous OMD with a disease-free interval <2 years, systemic therapy followed by restaging to consider local treatment was considered as treatment (consensus). For metachronous OMD with a disease-free interval >2 years, either upfront local treatment or systemic treatment fol-lowed by restaging was considered as treatment (fair agreement). Conclusion: The OMEC project has resulted in a multidisciplinary European consensus state -ment for the definition, diagnosis and treatment of oligometastatic oesophagogastric adeno-carcinoma and squamous cell cancer. This can be used to standardise inclusion criteria for future clinical trials. 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Show less
Background and purpose: Neoadjuvant chemoradiotherapy (nCRT) is used in locally recurrent rectal cancer (LRRC) to increase chances of a radical surgical resection. Delineation in LRRC is hampered... Show moreBackground and purpose: Neoadjuvant chemoradiotherapy (nCRT) is used in locally recurrent rectal cancer (LRRC) to increase chances of a radical surgical resection. Delineation in LRRC is hampered by complex disease presentation and limited clinical exposure. Within the PelvEx II trial, evaluating the benefit of chemotherapy preceding nCRT for LRRC, a delineation guideline was developed by an expert LRRC team.Materials and methods: Eight radiation oncologists, from Dutch and Swedish expert centres, participated in two meetings, delineating GTV and CTV in six cases. Regions at-risk for re-recurrence or irradical resection were identified by eleven expert surgeons and one expert radiologist. Target volumes were evaluated multidisciplinary. Inter-observer variation was analysed.Results: Inter-observer variation in delineation of LRRC appeared large. Multidisciplinary evaluation per case is beneficial in determining target volumes. The following consensus regarding target volumes was reached. GTV should encompass all tumour, including extension into OAR if applicable. If the tumour is in fibrosis, GTV should encompass the entire fibrotic area. Only if tumour can clearly be distinguished from fibrosis, GTV may be reduced, as long as the entire fibrotic area is covered by the CTV. CTV is GTV with a 1 cm margin and should encompass all at-risk regions for irradical resection or re-recurrence. CTV should not be adjusted towards other organs. Multifocal recurrences should be encompassed in one CTV. Elective nodal delineation is only advised in radiotherapy-naïve patients.Conclusion: This study provides a first consensus-based delineation guideline for LRRC. Analyses of re-recurrences is needed to understand disease behaviour and to optimize delineation guidelines accordingly. Show less
Osong, B.; Masciocchi, C.; Damiani, A.; Bermejo, I.; Meldolesi, E.; Chiloiro, G.; ... ; Soest, J. van 2022
Background and Purpose: Tumor recurrence, a characteristic of malignant tumors, is the biggest concern for rectal cancer survivors. The epidemiology of the disease calls for a pressing need to... Show moreBackground and Purpose: Tumor recurrence, a characteristic of malignant tumors, is the biggest concern for rectal cancer survivors. The epidemiology of the disease calls for a pressing need to improve healthcare quality and patient outcomes. Prediction models such as Bayesian networks, which can probabilistically reason under uncertainty, could assist caregivers with patient management. However, some concerns are associated with the standard approaches to developing these structures in medicine. Therefore, this study aims to compare Bayesian network structures that stem from these two techniques. Materials and Methods: A retrospective analysis was performed on 6754 locally advanced rectal cancer (LARC) patients enrolled in 14 international clinical trials. Local tumor recurrence at 2, 3, and 5-years was defined as the endpoints of interest. Five rectal cancer treating physicians from three countries elicited the expert structure. The algorithmic structure was inferred from the data with the hill-climbing algorithm. Structural performance was assessed with calibration plots and area under the curve values. Results: The area under the curve for the expert structure on the training and validation data was above 0.9 and 0.8, respectively, for all the time points. However, the algorithmic structure had superior predictive performance over the expert structure for all time points of interest. Conclusion: We have developed and internally validated a Bayesian networks structure from experts' opinions, which can predict the risk of a LARC patient developing a tumor recurrence at 2, 3, and 5 years. Our result shows that the algorithmic-based structures are more performant and less interpretable than expert based structures. Show less
Kroese, T.E.; Hillegersberg, R. van; Schoppmann, S.; Deseyne, P.R.A.J.; Nafteux, P.; Obermannova, R.; ... ; OMEC Working Grp 2022
Background: Consensus about the definition and treatment of oligometastatic oesophagogastric cancer is lacking. Objective: To assess the definition and treatment of oligometastatic oesophagogastric... Show moreBackground: Consensus about the definition and treatment of oligometastatic oesophagogastric cancer is lacking. Objective: To assess the definition and treatment of oligometastatic oesophagogastric cancer across multidisciplinary tumour boards (MDTs) in Europe. Material and methods: European expert centers (n Z 49) were requested to discuss 15 real-life cases in their MDT with at least a medical, surgical, and radiation oncologist present. The cases varied in terms of location and number of metastases, histology, timing of detection (i.e. synchronous versus metachronous), primary tumour treatment status, and response to systemic therapy. The primary outcome was the agreement in the definition of oligometastatic disease at diagnosis and after systemic therapy. The secondary outcome was the agreement in treatment strategies. Treatment strategies for oligometastatic disease were categorised into up -front local treatment (i.e. metastasectomy or stereotactic radiotherapy), systemic therapy followed by restaging to consider local treatment or systemic therapy alone. The agreement across MDTs was scored to be either absent/poor (< 50%), fair (50%-75%), or consensus (>= 75%). Results: A total of 47 MDTs across 16 countries fully discussed the cases (96%). Oligometastatic disease was considered in patients with 1-2 metastases in either the liver, lung, retroperitoneal lymph nodes, adrenal gland, soft tissue or bone (consensus). At follow-up, oligometastatic disease was considered after a median of 18 weeks of systemic therapy when no progression or progression in size only of the oligometastatic lesion(s) was seen (consensus). If at restaging after a median of 18 weeks of systemic therapy the number of lesions progressed, this was not considered as oligometastatic disease (fair agreement). There was no consensus on treatment strategies for oligometastatic disease. Conclusion: A broad consensus on definitions of oligometastatic oesophagogastric cancer was found among MDTs of oesophagogastric cancer expert centres in Europe. However, high practice variability in treatment strategies exists. (C) 2022 The Authors. Published by Elsevier Ltd. Show less
Background and purpose: A matched comparison of external beam radiotherapy (EBRT) versus brachytherapy recently demonstrated that EBRT appears at least as effective for palliating dysphagia in... Show moreBackground and purpose: A matched comparison of external beam radiotherapy (EBRT) versus brachytherapy recently demonstrated that EBRT appears at least as effective for palliating dysphagia in patients with incurable esophageal cancer. The aim of this analysis was to compare patient-reported outcomes (PROs) after EBRT versus brachytherapy.Materials and methods: In a multicenter prospective cohort study, patients with incurable esophageal cancer requiring palliation of dysphagia were included to undergo EBRT (20 Gy in 5 fractions). This EBRT cohort was compared to the single-dose 12 Gy brachytherapy cohort of the previously reported SIRECtrial. Propensity score matching was applied to adjust for baseline imbalances. The primary endpoint of dysphagia improvement was reported previously. PROs were secondary outcomes and assessed at baseline and 3 months after treatment using EORTC QLQ-C30 and QLQ-OES18 questionnaires.Results: A total of 115 enrolled EBRT patients and 93 brachytherapy patients were eligible. After matching, 69 well-balanced pairs remained. At follow-up, significant deteriorations in functioning (i.e. physical, role, social), pain, appetite loss, and trouble with taste were observed after brachytherapy. In the EBRT group, such deterioration was observed only for role functioning, while significant improvements in trouble with eating and pain were found. Between-group comparison showed mostly comparable PRO changes, but significantly favored EBRT with regard to nausea, vomiting, pain, and appetite loss.Conclusion: Short course EBRT results in similar or better PROs at 3 months after treatment compared to single-dose brachytherapy for the palliation of malignant dysphagia. These findings further support its use and inclusion in clinical practice guidelines. (C) 2020 The Author(s). Published by Elsevier B.V. Show less
Introduction: Short-course external beam radiotherapy (EBRT) and intraluminal brachytherapy are both accepted treatments for the palliation of dysphagia in patients with incurable esophageal cancer... Show moreIntroduction: Short-course external beam radiotherapy (EBRT) and intraluminal brachytherapy are both accepted treatments for the palliation of dysphagia in patients with incurable esophageal cancer. We compared the effects of both treatments from two prospective studies.Methods: We performed a multicenter prospective cohort study of patients with metastasized or otherwise incurable esophageal cancer requiring palliation of dysphagia from September 2016 to March 2019. Patients were treated with EBRT in five fractions of 4 Gy. Data were compared with all patients treated with a single brachytherapy dose of 12 Gy in the SIREC (Stent or Intraluminal Radiotherapy for inoperable Esophageal Cancer) trial, both between the original cohorts and between 1:1 propensity score-matched cohorts. The primary end point was an improvement of dysphagia at 3 months without reintervention. The secondary end points included toxicity and time-to-effect.Results: A total of 115 patients treated with EBRT and 93 patients who underwent brachytherapy were eligible for analysis. In the original cohorts, dysphagia improved after EBRT in 79% of patients compared with 64% after brachytherapy (p = 0.058). Propensity score matching resulted in 69 patients in each cohort well-balanced at baseline. Improvement of dysphagia was observed in 83% after EBRT versus 64% after brachytherapy (p = 0.048). In responding patients, improvement of dysphagia at 2 weeks was observed in 67% after EBRT compared with 35% after brachytherapy, and the maximum effect was reached after 4 weeks in 55% and 33%, respectively. Severe toxicity occurred in 3% of patients after EBRT compared with 13% after brachytherapy.Conclusions: Short-course EBRT appears at least as effective as brachytherapy in the palliation of dysphagia in patients with esophageal cancer. (C) 2020 International Association for the Study of Lung Cancer. Published by Elsevier Inc. Show less
Ende, R.P.J. van den; Peters, F.P.; Harderwijk, E.; Rutten, H.; Bouwmans, L.; Berbee, M.; ... ; Kerkhof, E.M. 2020
Background The STAR-TReC trial is an international multi-center, randomized, phase II study assessing the feasibility of short-course radiotherapy or long-course chemoradiotherapy as an alternative... Show moreBackground The STAR-TReC trial is an international multi-center, randomized, phase II study assessing the feasibility of short-course radiotherapy or long-course chemoradiotherapy as an alternative to total mesorectal excision surgery. A new target volume is used for both (chemo)radiotherapy arms which includes only the mesorectum. The treatment planning QA revealed substantial variation in dose to organs at risk (OAR) between centers. Therefore, the aim of this study was to determine the treatment plan variability in terms of dose to OAR and assess the effect of a national study group meeting on the quality and variability of treatment plans for mesorectum-only planning for rectal cancer. Methods Eight centers produced 25 x 2 Gy treatment plans for five cases. The OAR were the bowel cavity, bladder and femoral heads. A study group meeting for the participating centers was organized to discuss the planning results. At the meeting, the values of the treatment plan DVH parameters were distributed among centers so that results could be compared. Subsequently, the centers were invited to perform replanning if they considered this to be necessary. Results All treatment plans, both initial planning and replanning, fulfilled the target constraints. Dose to OAR varied considerably for the initial planning, especially for dose levels below 20 Gy, indicating that there was room for trade-offs between the defined OAR. Five centers performed replanning for all cases. One center did not perform replanning at all and two centers performed replanning on two and three cases, respectively. On average, replanning reduced the bowel cavity V20Gy by 12.6%, bowel cavity V10Gy by 22.0%, bladder V35Gy by 14.7% and bladder V10Gy by 10.8%. In 26/30 replanned cases the V10Gy of both the bowel cavity and bladder was lower, indicating an overall lower dose to these OAR instead of a different trade-off. In addition, the bowel cavity V10Gy and V20Gy showed more similarity between centers. Conclusions Dose to OAR varied considerably between centers, especially for dose levels below 20 Gy. The study group meeting and the distribution of the initial planning results among centers resulted in lower dose to the defined OAR and reduced variability between centers after replanning. Show less
Braak, R.R.J.C. van den; Rijssen, L.B. van; Kleef, J.J. van; Vink, G.R.; Berbee, M.; Henegouwen, M.I.V.; ... ; PLCRC Working Grp 2018
Purpose: To assess the effect of additional magnetic resonance imaging (MRI) alongside the planning computed tomography (CT) scan on target volume delineation in pancreatic cancer patients.Material... Show morePurpose: To assess the effect of additional magnetic resonance imaging (MRI) alongside the planning computed tomography (CT) scan on target volume delineation in pancreatic cancer patients.Material and methods: Eight observers (radiation oncologists) from six institutions delineated the gross tumor volume (GTV) on 3DCT, and internal GTV (iGTV) on 4DCT of four pancreatic cancer patients, while MRI was available in a second window (CT+MRI). Variations in volume, generalized conformity index (CIgen), and overall observer variation, expressed as standard deviation (SD) of the distances between delineated surfaces, were analyzed. CIgen is a measure of overlap of the delineated iGTVs (1=full overlap, 0=no overlap). Results were compared with those from an earlier study that assessed the interobserver variation by the same observers on the same patients on CT without MRI (CT-only).Results: The maximum ratios between delineated volumes within a patient were 6.1 and 22.4 for the GTV (3DCT) and iGTV (4DCT), respectively. The average (root-mean-square) overall observer variations were SD=0.41cm (GTV) and SD=0.73cm (iGTV). The mean CIgen was 0.36 for GTV and 0.37 for iGTV. When compared to the iGTV delineated on CT-only, the mean volumes of the iGTV on CT+MRI were significantly smaller (32%, Wilcoxon signed-rank, p<.0005). The median volumes of the iGTV on CT+MRI were included for 97% and 92% in the median volumes of the iGTV on CT. Furthermore, CT+MRI showed smaller overall observer variations (root-mean-square SD=0.59cm) in six out of eight delineated structures compared to CT-only (root-mean-square SD=0.72cm). However, large local observer variations remained close to biliary stents and pathological lymph nodes, indicating issues with instructions and instruction compliance.Conclusions: The availability of MRI images during target delineation of pancreatic cancer on 3DCT and 4DCT resulted in smaller target volumes and reduced the interobserver variation in six out of eight delineated structures. Show less
