Background/Objectives: Radiation therapy is a common treatment modality for non-small-cell and small-cell lung cancer that can be associated with considerable side effects, mainly reactions of healthy tissues in the radiation field. Radiation therapy may lead to significant fatigue, which can potentially be mitigated by maintaining or increasing physical activity during treatment. Since achieving this goal may be a challenge for patients, they may benefit from a mobile application reminding them daily to perform a predefined number of steps. Such a reminder app will be investigated prospectively in a phase 2 trial. The current APART-LUNG study (NCT07380815) is a mandatory study for designing the prospective trial. Methods: The main objective of the APART-LUNG (exploratory non-interventional) study is to report patterns of physical activity during radiation therapy for lung cancer patients and generate hypotheses based on our findings. Our primary endpoint is the within-patient difference in weekly average steps per wear hour of the smartphone (week 5 minus week 1 of radiation therapy), and our secondary aim is to estimate differences in operational measures (wear time of the smartphone) between week 5 and week 1. The sample size of approximately 20 patients (full analysis set) allows us to detect a moderate-to-large standardized within-patient difference and is driven by feasibility and the intent to obtain preliminary estimates of effect size and variability. The results of the APART-LUNG study will be very important for appropriately designing a phase 2 trial.

Background/Objectives: A symptom-based scoring system (0–9 points) for the identification of radiation pneumonitis was previously evaluated in lung cancer patients without age restrictions. A threshold of five points appeared optimal to detect pneumonitis. Since elderly patients have a higher pneumonitis risk, this threshold may not be valid for this group. The POLCAR trial evaluated performance and threshold selection in elderly patients. Methods: Diagnostic discrimination was assessed by receiver operating characteristic analysis. The areas under the curve (AUCs) and a null hypothesis that AUC equaled 0.7 were evaluated. Youden indices were used to identify candidate thresholds. In addition, the change from baseline and patient satisfaction were assessed. The dissatisfaction rate should be <20%. Results: Thirty new patients, plus 31 patients from another prospective trial with an almost identical design, qualified for analyses. The AUC for the pneumonitis score was 0.85 (95% confidence interval: 0.73–0.97). The highest Youden index (0.535) was observed for a threshold of four points. A threshold of five points led to a similar Youden index, a lower sensitivity, and higher specificity. An increase from the baseline by two points had a Youden index of 0.566 and a sensitivity of 100%, while an increase by three points had a Youden index of 0.550 and a specificity of 92.5%. Statistically superior discrimination for the change-from-baseline approach was not observed. The dissatisfaction rate was 5.4%. Conclusions: The scoring system showed good discrimination and high acceptance by patients. A threshold of four points appeared appropriate use in routine screening for the early detection of pneumonitis, whereas the change from baseline was considered useful as an exploratory tool when baseline data were available. Since only eight pneumonitis events occurred, threshold estimates require external validation.

Background: Radiation therapy with or without systemic treatment for lung cancer can cause adverse reactions, e.g., fatigue. Affected patients may experience a decrease in physical activity and, as a consequence, be unable to receive the complete assigned treatment. Physical exercise may be helpful. A benefit of exercise regarding completion of systemic treatment and quality of life was previously suggested. Irradiated patients may benefit as well. A smartphone-based app reminding patients to make a minimum number of steps might positively influence physical activity. The prototype of an app called “Step Reminder” was recently finalized. The randomized APPAREL trial (NCT07627022) evaluates whether this app can improve physical activity during irradiation for lung cancer. Methods: The primary endpoint of this phase 2 trial focuses on the within-patient change regarding the mean number of daily steps (week 5 minus week 1). Secondary objectives include satisfaction with the application and its impact on the perception of digital health technology. Patients are randomized 1:1 to be treated with a standard approach (conventionally fractionated irradiation with or without systemic treatment) supported by the “Step Reminder” app (Arm A) or standard treatment without the app (Arm B). The app provides reminders several times per day to walk a pre-defined number of steps. To make sure that the required 28 patients are included in the primary analysis population (full analysis set), 32 patients have to be randomized. Results: At this stage, results are not available. Conclusions: It is expected that the app will have a positive effect on the patients’ physical activity (number of steps).

Background: Radiotherapy commonly requires a computed tomography (CT) dataset for treatment planning. Artificial intelligence-supported radiotherapy systems now enable online adaptive workflows that reduce uncertainties resulting from the use of diagnostic instead of planning CT images. The aim was to identify patient groups that may particularly benefit from adaptive emergency treatments. Methods: In this retrospective exploratory study, 16 patients comprising 21 planning target volumes (PTVs) were evaluated. PTVs were classified as predominantly soft-tissue or bony. To verify the geometric agreement between scheduled and adapted treatment plans, these subgroups were analyzed using absolute planning target volume change, the Dice similarity coefficient (DSC), and the 95th percentile Hausdorff distance, and their association with V95% PTV coverage was evaluated. Results: Bony targets showed higher geometric reproducibility than soft-tissue-dominant lesions, with higher median DSC values (0.96 vs. 0.88) and lower median HD95 values (2.6 mm vs. 5.5 mm). Online adaptation improved coverage in 20 of 21 PTVs, while predominantly soft-tissue PTVs showed potentially greater benefit from online adaptation. Conclusions: Soft-tissue-dominant PTVs showed greater geometric variability and potentially greater benefit from adaptation, whereas selected bone-dominant cases may be suitable for faster conventional workflows. Given the small exploratory cohort, these results require further confirmation.

Background/Objectives: Moderate hypo-fractionation is frequently used for irradiation of prostate cancer. Irrespective of dose fractionation, radiotherapy can lead to radiation cystitis. To reduce urinary toxicity, it is important to avoid bladder volumes < 200 mL. This may be facilitated with an app reminding patients to drink water prior to irradiation. This non-randomized multicenter REFILL-PAC-HYPO trial with external control evaluated the association between use of the reminder app and bladder filling during a radiotherapy course. Methods: Twenty-two patients receiving hypo-fractionated irradiation (20 × 3.0 Gy) were planned to be supported by the app (the prospective experimental group) and compared to 95 patients who were not supported by the app (the historical control group). The primary endpoint was the number of fractions with a bladder volume < 200 mL. Secondary objectives included satisfaction with the app and its impact on using health technology. Results: The median number of fractions with a bladder volume < 200 mL was lower in the app-supported experimental group (13; interquartile range: 6, 18 vs. 19; interquartile range: 14, 20). The Wilcoxon–Mann–Whitney test indicated a significant between-group difference (p = 0.0009) with a Hodges–Lehmann estimate of −4 fractions (95% confidence interval: −7 to −2). Supportive analyses used a multivariable negative binomial model (rate ratio: 0.71; p = 0.0018) and propensity score analysis (p = 0.012). The dissatisfaction rate was 20%; 78.9% of patients stated at least a little impact of trial participation on the use of health technology. Conclusions: Given the limitations of this study, the app was associated with fewer fractions with a bladder volume < 200 mL in this cohort. Although patient dissatisfaction was considered acceptable, further optimization of the app would be welcomed. Moreover, the findings of this study require confirmation in a randomized trial that also considers urinary toxicity.