Pharmacokinetics of cisplatin in the systemic versus hyperthermic intrathoracic or intraperitoneal chemotherapy.

Objective: To compare the pharmacokinetics and adverse effects of cisplatin administered via intravenous infusion for systemic chemotherapy (SC) versus injection into the perfusate during hyperthermic intrathoracic chemotherapy (HITHOC) or hyperthermic intraperitoneal chemotherapy (HIPEC).

Methods: Total 60 patients who received SC, HITHOC, or HIPEC in the Department of Oncology, Tangdu Hospital, were enrolled into this study. After administering same dose of cisplatin (40 mg) via either intravenous infusion (SC group) or injection into the perfusate during the HITHOC or HIPEC procedure, concentration of cisplatin in the plasma as well as in the hyperthermic perfusate at various time points was quantified by HPLC analysis. The area under the plasma or perfusate concentration-time curve over the last 24h dosing interval (AUC_0-24h), mean residence time over the 24 h (MRT_0-24h), terminal elimination half-life (t_1/2z), time to peak concentration (T_max), apparent clearance (Clz/F), and peak concentration (C_max) in the perfusate and plasma were compared.

Results: In the perfusate, the AUC_0-24h (64.32 ± 27.12 µg/mL·h) and C_max (21.62 ± 5.88 µg/mL) were significantly higher in the HITHOC group compared to that in the HIPEC group (31.68 ± 13.29 µg/mL·h and 16.96 ± 5.54 µg/mL, respectively, p ≤ 0.01). In contrast, MRT_0-∞, t_1/2z, and Clz/F were significantly lower in the HITHOC group compared to that in the HIPEC group (p < 0.01). In the plasma, average AUC_0-24h and C_max of the HITHOC group were 2.57 ± 0.55 µg/mL·h and 0.26 ± 0.08 µg/mL, respectively, which were significantly lower than that of systemic chemotherapy (SC) group (3.26 ± 0.56 µg/mL·h and 0.69 ± 0.14 µg/mL, respectively, p < 0.01), but no difference compared to that of HIPEC group (3.02 ± 0.52 µg/mL·h and 0.40 ± 0.15 µg/mL, respectively, p > 0.05). In contrast, MRT_0-24h and T_max in the plasma of HITHOC group were significantly longer compared to that of SC group (p < 0.05), but no significant difference compared to that of HIPEC group (p > 0.05). Absolute bioavailability of cisplatin in the thoracic (HITHOC group) and abdominal (HIPEC group) cavities was 20 and 10 times higher than that in the blood administered intravenously (SC group), respectively. There was no significant difference in the incidence of adverse events among the three groups (p < 0.05).

Conclusion: The current study demonstrated that, in the perfusate, AUC_0-24h and C_max of cisplatin was significantly higher in the group of HITHOC compared to that of HIPEC, and that, in the plasma, AUC_0-24h and C_max of cisplatin was lower in the group of HITHOC compared to that of HIPEC or SC group. This study provided pharmacokinetic evidence to further support the concept that topical application of chemotherapeutic drug through minimally invasive HITHOC or HIPEC may enhance local exposure compared to systemic chemotherapy for the patients with malignant pleural effusion or ascites.