Here is the design of a clinical trial:

Official Title: Recurrent Disease Detection After Resection of Pancreatic Adenocarcinoma Using a Standardized Surveillance Strategy: a Nationwide Randomized Controlled Trial

Included conditions:
- Resectable Pancreatic Ductal Adenocarcinoma
- Recurrent Pancreatic Ductal Adenocarcinoma

Study Armgroups:
- {'label': 'Standardized surveillance', 'type': 'EXPERIMENTAL', 'description': 'Standardized surveillance strategy with routine imaging and serum tumor marker testing.', 'interventionNames': ['Other: Standardized surveillance']}
- {'label': 'Non-standardized surveillance', 'type': 'NO_INTERVENTION', 'description': 'Non-standardized surveillance strategy according to current clinical practice.'}

Interventions:
- {'type': 'OTHER', 'name': 'Standardized surveillance', 'description': 'Standardized 3-monthly surveillance with routine imaging and serum tumor marker testing.', 'armGroupLabels': ['Standardized surveillance']}

Primary Outcomes:
- {'measure': 'Overall survival', 'description': 'The interval between the date of PDAC resection and either death from any cause or last follow-up.', 'timeFrame': 'From date of PDAC resection until date of death from any cause or date of last follow-up, whichever came first, assessed up to 24 months'}

Please estimate the sample size based on the assumption: 
Statistical power of 80%, a 0.05 two-sided significance level, a drop-out rate of 1%, a baseline event rate of 3.5%, and a follow-up duration of 30 months.
Sample size {14}
        A retrospective study by Elmi et al. demonstrated that the median overall survival after primary tumor resection was 30.4Â months in 163 patients who received routine imaging surveillance, as compared with 17.1Â months in 66 patients receiving clinical follow-up without imaging [32]. Data from 1580 patients who underwent PDAC resection between 2014 and 2019 within the Netherlands showed a median overall survival of 33.6Â months (95% confidence interval (CI) 29.4â38.2Â months) in 284 patients who received routine follow-up imaging and 20.8Â months (95% CI 19.8â22.6Â months) in 1296 patients undergoing a symptomatic follow-up approach without routine imaging (Fig.Â 2). Combining these outcomes results in an expected median survival of 32.0Â months vs. 19.0Â months for patients in the intervention and control arm of the RADAR-PANC trial, respectively.Fig.Â 2KaplanâMeier curve comparing overall survival between patients with routine follow-up imaging and symptomatic follow-up in the Netherlands between 2014â2019 (unpublished data)
        As we expect 80% of patients to accept the experimental intervention offered in the intervention arm of the study, an estimated refusal rate of 20% needs to be taken into account. This leads to a decrease of the overall survival to 29.4Â months (80%âÃâ32.0Â monthsâ+â20%âÃâ19.0Â months) for patients in the intervention arm. Moreover, despite that current non-standardized follow-up in daily clinical practice mainly results in a symptomatic follow-up approach without routine imaging, data from our recurrence database showed that 85/1580 patients (5%) did nonetheless receive routine follow-up imaging based on shared-decision making (the remaining 199/284 patients (70%) who received routine follow-up imaging participated in a clinical study with a study-specific follow-up including routine imaging). This results in a slight increase of the suspected overall survival in the control arm to 19.7Â months (95%âÃâ19.0Â monthsâ+â5%âÃâ32.0Â months). The clinically relevant survival difference of 29.4Â months vs. 19.7Â months for the intervention and control arm, respectively, also approximates the mean survival difference of 9.5Â months presented in the meta-analysis from Halle-Smith et al. [33]. These numbers correspond to a relative hazard (RH) of survival of 1.49, which is used to calculate the sample size of the study. Furthermore, as we expect a minimal level of loss to follow-up in this surveillance study, a censoring rate of 1% is expected each month.
        To detect a 49% overall survival improvement (RH of survival 1.49) for patients in the intervention group, as compared with the control group, with a statistical power of 80% and a 0.05 two-sided significance level, a sample size of 306 patients is required. This calculation was based on the assumption of an exponential model, a median overall survival of 19.7Â months in the control arm, a follow-up duration of 30Â months, a drop-out rate of 1% and a baseline event rate of 3.5%. Following this calculation, we plan to include 306 patients in total: 153 patients in the recurrence-focused follow-up group and 153 patients in the non-standardized, symptomatic follow-up group.