Untersuchungen zum Stellenwert der diffusionsgewichteten Kernspintomographie in der Verlaufsbeurteilung nach primärer Strahlentherapie des Lungenkarzinoms

Hintergrund: Die Computertomographie (CT) ist die Standarduntersuchung in der Nachsorge des nicht-kleinzelligen Lungenkarzinoms (NSCLC) nach erfolgter Radio(chemo)therapie. Die CT weist allerdings häufig Limitierungen bei der diagnostischen Abgrenzung des Primärtumors von einer radiogenen Schädigung der Lunge (Radiation-induced Lung Toxicity [RILT]) auf. Die diffusionsgewichtete Kernspintomographie (DWI) ermöglicht prinzipiell eine genauere Erkennung von vitalem Tumorgewebe. Ziel der Studie ist es, den diagnostischen Mehrwert der DWI im Vergleich zur CT im Rahmen der Nachsorge des NSCLC zu untersuchen. Patienten und Methoden: Bei 12 Patienten mit einem NSCLC in den Stadien I–III mit Indikation für eine Radio(chemo)therapie wurden vor der Strahlentherapie sowie anschließend nach 3, 6 und 12 Monaten eine CT- und zusätzlich eine MRT-inkl.-DWI-Untersuchungen durchgeführt. Für die thorakale MRT wurden mittels eines 1,5T-Scanners (Siemens, Magnetom@ Aera) atemgetriggerte axiale T2-Sequenzen sowie, ohne Atemgating, DWI-Sequenzen akquiriert (b = 0, 800, 1400 und eine ADC-Map). Die Primärtumore wurden volumetriert und ihre Größenänderung im Verlauf nach RECIST (Version 1.1) ausgewertet. Die Beurteilung der RILT erfolgte nach einem für CT und MRT einheitlichen vierstufigen Scoring-System (0 = keine RILT, 1 = retikuläre Parenchymveränderungen, 2 = inhomogene Konsolidierungen, 3 = homogene Konsolidierungen). Ergebnisse: Es ergab sich kein signifikanter Unterschied in der Auswertung des längsaxialen Durchmessers (LD) der untersuchten Tumore und des Tumorvolumens zwischen MRT und korrespondierender CT (p = 0.6221 und p = 0.25). Die Auswertung der RILT zeigte eine sehr hohe Korrelation zwischen MRT und CT (3-Monatskontrolle: r = 0.8750, und 12-Monatskontrolle: r = 0.903). Die Analyse der ADC-Werte suggeriert, dass Patienten mit einem guten lokalen Tumoransprechen bereits initial und im weiteren Verlauf höhere ADC-Werte aufweisen als Patienten mit einem geringeren lokalen Ansprechen. Schlussfolgerung: Die DWI-MRT ist im Rahmen der Nachsorge vergleichbar mit der CT bei der Bestimmung des Tumorvolumens. Die Ausprägung radiogener Lungenschäden (RILT) kann verlässlich in der MRT erfasst werden. Die DWI-MRT ermöglicht im Vergleich mit der CT insgesamt eine zuverlässigere Beurteilung des Tumoransprechens. ADC-Werte haben möglicherweise einen Stellenwert als prognostische Marker.Background: Computed tomography (CT) is the standard examination in the follow-up of non-small cell lung cancer (NSCLC) after radio(chemo)therapy. However, CT often has limitations in the diagnostic differentiation of the primary tumour from radiogenic damage to the lung (radiation-induced lung toxicity [RILT]). Diffusion-weighted magnetic resonance imaging (DWI) in principle allows a more accurate detection of vital tumour tissue. The aim of the study is to investigate the diagnostic added value of DWI compared to CT in the follow-up of NSCLC. Patients and methods: In 12 patients with stage I–III NSCLC with indication for radio(chemo)therapy, CT and MRI including DWI examinations were performed before radiotherapy and subsequently after 3, 6 and 12 months. For thoracic MRI, breath-triggered axial T2 sequences and, without breath gating, DWI sequences were acquired using a 1.5T scanner (Siemens, Magnetom@ Aera) (b=0, 800, 1400 and an ADC-map). The primary tumours were volumetrised and their size change during the course was evaluated according to RECIST (version 1.1). RILT was assessed according to a four-level scoring system uniform for CT and MRI (0 = no RILT, 1 = reticular parenchymal changes, 2 = inhomogeneous consolidations, 3 = homogeneous consolidations). Results: There was no significant difference in the evaluation of the longitudinal axial diameter (LD) of the examined tumours and tumour volume between MRI and corresponding CT (p = 0.6221 and p = 0.25). Evaluation of RILT showed a very high correlation between MRI and CT (3 month control: r = 0.8750, and 12 month control: r = 0.903). The analysis of the ADC values suggests that patients with a good local tumour response already initially and in the further course show higher ADC values than patients with a lower local response. Conclusion: DWI-MRI is comparable to CT in determining tumour volume in the context of follow-up. The extent of radiogenic lung damage (RILT) can be reliably detected by MRI. DWI MRI provides a more reliable overall assessment of tumour response compared to CT. ADC values may have value as prognostic markers

Diffusion-weighted MRI improves response assessment after definitive radiotherapy in patients with NSCLC

Background Computed tomography (CT) is the standard procedure for follow-up of non-small-cell lung cancer (NSCLC) after radiochemotherapy. CT has difficulties differentiating between tumor, atelectasis and radiation induced lung toxicity (RILT). Diffusion-weighted imaging (DWI) may enable a more accurate detection of vital tumor tissue. The aim of this study was to determine the diagnostic value of MRI versus CT in the follow-up of NSCLC. Methods Twelve patients with NSCLC stages I-III scheduled for radiochemotherapy were enrolled in this prospective study. CT with i.v. contrast agent and non enhanced MRI were performed before and 3, 6 and 12 months after treatment. Standardized ROIs were used to determine the apparent diffusion weighted coefficient (ADC) within the tumor. Tumor size was assessed by the longest longitudinal diameter (LD) and tumor volume on DWI and CT. RILT was assessed on a 4-point-score in breath-triggered T2-TSE and CT. Results There was no significant difference regarding LD and tumor volume between MRI and CT (p ≥ 0.6221, respectively p ≥ 0.25). Evaluation of RILT showed a very high correlation between MRI and CT at 3 (r = 0.8750) and 12 months (r = 0.903). Assessment of the ADC values suggested that patients with a good tumor response have higher ADC values than non-responders. Conclusions DWI is equivalent to CT for tumor volume determination in patients with NSCLC during follow up. The extent of RILT can be reliably determined by MRI. DWI could become a beneficial method to assess tumor response more accurately. ADC values may be useful as a prognostic marker

Low skeletal muscle mass is predictive of dose-limiting toxicities in head and neck cancer patients undergoing low-dose weekly cisplatin chemoradiotherapy.

BackgroundThe dose-limiting effect of CT-assessed low skeletal muscle mass (LSMM) measured at the level of the third cervical vertebra has been found in head and neck cancer patients receiving high-dose cisplatin chemoradiotherapy. The aim of this study was to investigate the predictive factors for dose-limiting toxicities (DLTs) using low-dose weekly chemoradiotherapy.Materials and methodsHead and neck cancer patients receiving definite chemoradiotherapy with weekly 40 mg/m2 body surface area (BSA) cisplatin or paclitaxel 45 mg/m2 BSA and carboplatin AUC2 were consecutively included and retrospectively analysed. Skeletal muscle mass was assessed using the muscle surface at the level of the third cervical vertebra in pretherapeutic CT scans. After stratification for LSMM DLT, acute toxicities and feeding status during the treatment were examined.ResultsDose-limiting toxicity was significantly higher in patients with LSMM receiving cisplatin weekly chemoradiotherapy. For paclitaxel/carboplatin, no significance regarding DLT and LSMM could be found. Patients with LSMM had significantly more dysphagia before treatment, although feeding tube placement before treatment was equal in patients with and without LSMM.ConclusionsLSMM is a predictive factor for DLT in head and neck patients treated with low-dose weekly chemoradiotherapy with cisplatin. For paclitaxel/carboplatin, further research must be carried out

Radiotherapy of Breast Cancer in Laterally Tilted Prone vs. Supine Position: What about the Internal Mammary Chain?

Background: In the multimodal breast-conserving curative therapy of some high-risk breast cancer patients, extended external beam radiotherapy (EBRT) not only to the breast but also to the supraclavicular fossa and the internal mammary chain (parasternal region (PSR)) is indicated. We report a dosimetric study on the EBRT of the breast (“B”) and the breast including PSR (“B + PSR”), comparing the supine and the laterally tilted prone patient positions in free breathing. Methods: The planning CT scans of 20 left- and 20 right-sided patients were analyzed. EBRT plans were calculated with 3D conformal EBRT (3D) and with intensity-modulated EBRT (IMRT) for “B” and “B + PSR” in the prone and supine positions. The mean and threshold doses were computed. The quality of EBRT plans was compared with an overall plan assessment factor (OPAF), comprising three subfactors, homogeneity, conformity, and radiogenic exposure of OAR. Results: In the EBRT of “B”, prone positioning significantly reduced the exposure of the OARs “heart” and “ipsilateral lung” and “lymphatic regions”. The OPAF was significantly better in the prone position, regardless of the planning technique or the treated breast side. In the EBRT of “B + PSR”, supine positioning significantly reduced the OAR “heart” exposure but increased the dose to the OARs “ipsilateral lung” and “lymphatic regions”. There were no significant differences for the OPAF, independent of the irradiated breast side. Only the IMRT planning technique increased the chance of a comparatively good EBRT plan. Conclusion: Free breathing prone positioning significantly improves plan quality in the EBRT of the breast but not in the EBRT of the breast + PSR

Radiotherapy of Breast Cancer in Laterally Tilted Prone vs. Supine Position: What about the Internal Mammary Chain?

Background: In the multimodal breast-conserving curative therapy of some high-risk breast cancer patients, extended external beam radiotherapy (EBRT) not only to the breast but also to the supraclavicular fossa and the internal mammary chain (parasternal region (PSR)) is indicated. We report a dosimetric study on the EBRT of the breast (“B”) and the breast including PSR (“B + PSR”), comparing the supine and the laterally tilted prone patient positions in free breathing. Methods: The planning CT scans of 20 left- and 20 right-sided patients were analyzed. EBRT plans were calculated with 3D conformal EBRT (3D) and with intensity-modulated EBRT (IMRT) for “B” and “B + PSR” in the prone and supine positions. The mean and threshold doses were computed. The quality of EBRT plans was compared with an overall plan assessment factor (OPAF), comprising three subfactors, homogeneity, conformity, and radiogenic exposure of OAR. Results: In the EBRT of “B”, prone positioning significantly reduced the exposure of the OARs “heart” and “ipsilateral lung” and “lymphatic regions”. The OPAF was significantly better in the prone position, regardless of the planning technique or the treated breast side. In the EBRT of “B + PSR”, supine positioning significantly reduced the OAR “heart” exposure but increased the dose to the OARs “ipsilateral lung” and “lymphatic regions”. There were no significant differences for the OPAF, independent of the irradiated breast side. Only the IMRT planning technique increased the chance of a comparatively good EBRT plan. Conclusion: Free breathing prone positioning significantly improves plan quality in the EBRT of the breast but not in the EBRT of the breast + PSR

The impact of palliative radiotherapy on health-related quality of life in patients with head and neck cancer – Results of a multicenter prospective cohort study

Purpose: Palliative radiotherapy for patients with head and neck cancer can be used to alleviate symptoms. Only a few studies have investigated its impact on patient-reported outcomes (PRO). Therefore, we conducted a prospective multicenter observational study. The primary objective was to assess changes in health-related quality of life (HrQoL) per PRO. Methods: Eligibility criteria included i.) head and neck cancer and ii.) palliative radiotherapy indicated (EQD2Gy < 60 Gy). The primary follow-up date was eight weeks after radiotherapy (t8w). PRO measures included the EORTC QLQ-C30 and EORTC QLQ-H&N43 and pain per Numeric Rating Scale (NRS). Per protocol, five PRO domains were to be reported in detail as well as PRO domains corresponding to a primary and secondary symptom as determined by the individual patient. We defined a minimal important difference (MID) of 10 points. Results: From 06/2020 to 06/2022, 61 patients were screened and 21 patients were included. Due to death or decline in health-status, HrQoL data was available for 18 patients at the first fraction and for eight patients at t8w. The MID was not met for the predefined domains in terms of mean values as compared from first fraction to t8w. Individually in those patients with available HrQoL data at t8w, 71% (5/7) improved in their primary and 40% (2/5) in their secondary symptom domain reaching the MID from first fraction to t8w, respectively. There was a significant improvement in pain per NRS in those patients with available data at t8w per Wilcoxon signed rank test (p = 0.041). Acute mucositis of grade ≥3 per CTCAE v5.0 occurred in 44% (8/18) of the patients. The median overall survival was 11 months. Conclusion: Despite low patient numbers and risk of selection bias, our study shows some evidence of a benefit from palliative radiotherapy for head and neck cancer as measured by PRO.German Clinical Trial Registry identifier: DRKS00021197