Werner, Elisa

Abstract Background: Pneumonitis caused by radiotherapy for lung cancer may be missed, since it often occurs only several months later. In a previous trial including patients of any age, a symptom-based scoring system was tested to facilitate the correct diagnosis of radiation pneumonitis. Since elderly lung cancer patients have a greater risk of developing this complication, a separate scoring system particularly for this age group appears reasonable. This trial investigates such a specific tool for elderly patients irradiated for lung cancer. Methods: Patients with lung cancer patients aged ≥65 years will be included in this prospective multi-center trial and complete paper-based questionnaires (symptom-based scoring system). Patients indicate and rate symptoms potentially caused by pneumonitis, namely cough, dyspnea, and fever, once a week during and up to 24 weeks following their radiotherapy course. If symptomatic (grade ≥2) pneumonitis is confirmed by corresponding diagnostic procedures, patients receive prednisolone whenever possible. The total score of the symptom-based scoring system, which ranges between 0 and 9 points, is correlated to pneumonitis (yes or no). The discriminative power of the scoring system is evaluated by calculating the area under the receiver operating characteristic curve (AUC). Optimality is defined as a cut-off score with sensitivity ≥90% and specificity ≥80%. In addition, the Youden index (sensitivity + specificity – 1) will be applied. Fifty-nine patients (18 with and 41 without pneumonitis) are required in the full analysis set. Assuming that 5% of the patients will not qualify for this set, 62 patients should be enrolled. In addition, patient satisfaction with the scoring system is evaluated. If the dissatisfaction rate is >20%, the score needs modifications; if the dissatisfaction rate is >40%, the scoring system is considered not useful. Discussion: If the optimal cut-off score facilitates the diagnosis of radiation pneumonitis and its discrimination from other lung diseases in elderly patients with lung cancer, it will contribute to the development of a mobile application for identification of radiation pneumonitis, which can be used by the patients at home. Trial registration: clinicaltrials.gov (NCT06480734; URL: https://clinicaltrials.gov/show/NCT06480734); protocol version 1.2, registered on 27th of June, 2024.

In Radiation Therapy Oncology Group 90-05, the maximum tolerated dose of single-fraction radiosurgery (SRS) for brain metastases of 21–30 mm was 18 Gy (biologically effective dose (BED) 45 Gy12). Since the patients in this study received prior brain irradiation, tolerable BED may be >45 Gy12 for de novo lesions. We investigated SRS and fractionated stereotactic radiotherapy (FSRT) with a higher BED for radiotherapy-naive lesions. Patients receiving SRS (19–20 Gy) and patients treated with FSRT (30–48 Gy in 3–12 fractions) with BED > 49 Gy12 for up to 4 brain metastases were compared for grade ≥ 2 radiation necrosis (RN). In the entire cohort (169 patients with 218 lesions), 1-year and 2-year RN rates were 8% after SRS vs. 2% and 13% after FSRT (p = 0.73) in per-patient analyses, and 7% after SRS vs. 7% and 10% after FSRT (p = 0.59) in per-lesion analyses. For lesions ≤ 20 mm (137 patients with 185 lesions), the RN rates were 4% (SRS) vs. 0% and 15%, respectively, (FSRT) (p = 0.60) in per-patient analyses, and 3% (SRS) vs. 0% and 11%, respectively, (FSRT) (p = 0.80) in per-lesion analyses. For lesions > 20 mm (32 patients with 33 lesions), the RN rates were 50% (SRS) vs. 9% (FSRT) (p = 0.012) in both per-patient and per-lesion analyses. In the SRS group, a lesion size > 20 mm was significantly associated with RN; in the FSRT group, lesion size had no impact on RN. Given the limitations of this study, FSRT with BED > 49 Gy12 was associated with low RN risk and may be safer than SRS for brain metastases > 20 mm.

A modern approach for brain metastases includes whole-brain radiotherapy plus simultaneous boost (WBRT+SIB). We developed a survival score in 128 patients treated with WBRT+SIB. Three models, each including three prognostic groups, were created. Positive predictive values (PPVs) for death ≤6 and survival ≥6 months were calculated. On multivariate analyses, performance score (KPS) and the number of brain metastases were significantly associated with survival. On univariate analyses, age showed a strong trend, and extra-cerebral cranial metastases a trend. In Model 1 (KPS, number of lesions), compared groups had 6-month survival rates of 15%, 38% and 57%. In Model 2 (KPS, lesions, age), rates were 17%, 33% and 75%, and in Model 3 (KPS, lesions, age, extra-cerebral metastases), 14%, 34% and 78%. PPVs for death ≤6 and survival ≥6 months were 85% and 57% (Model 1), 83% and 75% (Model 2), and 86% and 78% (Model 3). Thus, all models were accurate in predicting death ≤ 6 months; poor-prognosis patients may not benefit from SIB. Models 2 and 3 were superior in predicting survival ≥ 6 months. Given that Model 3 requires more data (including extensive staging), Model 2 is considered favorable for many patients. If extra-cerebral metastases are already known or extensive staging has been performed, Model 3 can also be used.

Radiotherapy of lung cancer may cause pneumonitis that generally occurs weeks or months following therapy and can be missed. This prospective trial aimed to pave the way for a mobile application (app) allowing early diagnosis of pneumonitis. The primary goal was the identification of the optimal cut-off of a score to detect pneumonitis of grade ≥2 after radiotherapy for lung cancer. Based on the severity of symptoms (cough, dyspnea, fever), scoring points were 0–9. Receiver operating characteristic (ROC)-curves were used to describe the sensitivity and specificity. The area under the ROC-curve (AUC) was calculated to judge the accuracy of the score, Youden-index was employed to define the optimal cut-off. Until trial termination, 57 of 98 patients were included. Eight of 42 patients evaluable for the primary endpoint (presence or absence of radiation pneumonitis) experienced pneumonitis. AUC was 0.987 (0.961–1.000). The highest sensitivity was achieved with 0–4 points (100%), followed by 5 points (87.5%), highest specificity with 5–6 points (100%). The highest Youden-index was found for 5 points (87.5%). The rate of patient satisfaction with the symptom-based scoring system was 93.5%. A cut-off of 5 points was identified as optimal to differentiate between pneumonitis and no pneumonitis. Moreover, pneumonitis was significantly associated with an increase of ≥3 points from baseline (p < 0.0001). The scoring system provided excellent accuracy and high patient satisfaction. Important foundations for the development of a mobile application were laid.