Background: The intraoperative detection of solitary pulmonary nodules (SPNs) continues to be a major challenge, especially in minimally invasive video-assisted thoracic surgery (VATS). The location, size, and intraoperative frozen section result of SPNs are decisive regarding the extent of lung resection. This feasibility study investigates the technical applicability of intraoperative contrast-enhanced ultrasonography (Io-CEUS) in minimally invasive thoracic surgery. Methods: In this prospective, monocentric clinical feasibility study, n = 30 patients who underwent Io-CEUS during elective minimally invasive lung resection for SPNs between October 2021 and February 2023. The primary endpoint was the technical feasibility of Io-CEUS during VATS. Secondary endpoints were defined as the detection and characterization of SPNs. Results: In all patients (female, n = 13; mean age, 63 ± 8.6 years) Io-CEUS could be performed without problems during VATS. All SPNs were detected by Io-CEUS (100%). SPNs had a mean size of 2.2 cm (0.5–4.5 cm) and a mean distance to the lung surface of 2.0 cm (0–6.4 cm). B-mode, colour-coded Doppler sonography, and contrast-enhanced ultrasound were used to characterize all tumours intraoperatively. Significant differences were found, especially in vascularization as well as in contrast agent behaviour, depending on the tumour entity. After successful lung resection, a pathologic examination confirmed the presence of lung carcinomas (n = 17), lung metastases (n = 10), and benign lung tumours (n = 3). Conclusions: The technical feasibility of Io-CEUS was confirmed in VATS before resection regarding the detection of suspicious SPNs. In particular, the use of Doppler sonography and contrast agent kinetics revealed intraoperative specific aspects depending on the tumour entity. Further studies on Io-CEUS and the application of an endoscopic probe for VATS will follow.

Hyperthermic intrathoracic chemotherapy (HITOC) is an additional intraoperative treatment option within the multimodality therapy of pleural malignancies. A chemotherapy perfusion with high-dose cisplatin is performed over a period of 60 min after surgical cytoreduction to improve local tumour control through the eradication of residual tumour cells. Although HITOC is increasingly used, there is only little scientific evidence about the necessary safety measures after HITOC. Therefore, the objective of this study was an analysis of cisplatin excretion via various body fluids after HITOC, with the aim of providing recommendations on occupational health and safety. Five patients undergoing HITOC were included. Before and after the HITOC, as well as during the following days, serum, urine, and bronchial secretion, as well as pleural effusion, were sampled. The platinum levels in the samples were measured using ICP-MS (inductively coupled plasma-mass spectrometry). Immediately after the HITOC, the mean levels of cisplatin increased dramatically in the serum (from 0.79 to 1349 µg/L), urine (from 3.48 to 10,528 µg/g creatinine), and bronchial secretion (from 0.11 to 156 µg/L). Thereafter, the cisplatin levels dropped to 133 µg/L in the serum and 994 µg/g creatinine in the urine within nine days after the HITOC. The AUC ratio shows 59% of the cisplatin being excreted via the urine after 48 h. The sampling of pleural effusion started 24 h after the HITOC, and the cisplatin levels decreased from 618 to 93 µg/L within nine days. Although the cisplatin levels in the body fluids of HITOC patients are much lower compared to patients receiving intravenous chemotherapy, a significant amount of cisplatin is excreted via these body fluids. Consequently, safety precautions must be implemented in the post-HITOC care of patients to avoid occupational exposure to cisplatin.

Background: Hyperthermic intrathoracic chemotherapy (HITOC) is an additive treatment option after surgical cytoreduction of pleural malignancies. Despite growing clinical experience and studies evaluating its feasibility, postoperative morbidity and mortality, as well as the effect on survival, there is still only little known about the local effects of HITOC on the lung parenchyma and tumour cells. The objective of this in vitro study was to evaluate the dose-dependent concentration and penetration depth of cisplatin in human lung tissue. Methods: In total, 40 patients were enrolled for elective lung resection, and wedge samples were taken to the laboratory. The visceral pleura was removed, and the decorticated lung tissue was incubated in cisplatin solutions of different concentrations (0.05, 0.075, and 0.1 mg/mL) at 42 °C over 60 min. Afterwards, platinum amounts in the lung tissue samples were measured using atomic absorption spectroscopy. Results: A strong decline of the cisplatin concentration was found until a depth of 3.5 mm, followed by a mild decline until a depth of 7.5 mm. In a depth of 0.5 mm, there was only a significant difference between 0.05 and 0.1 mg/mL (p = 0.03, Cohen’s d = 0.43). In a depth of 1.5 mm, there was an overall significant difference in cisplatin concentration dependent on dose (p = 0.027). In deeper tissue layers, no significant difference in cisplatin concentrations in the tissue was found. Conclusions: A dose-dependent increase of the cisplatin concentration was found for superficial tissue layers. This emphasises the relevance of sufficiently high intrathoracic concentrations of the chemotherapeutic agent. This study confirms that cisplatin penetrates lung tissue in therapeutically effective concentrations.