Distribution pattern and penetration depth of doxorubicin after pressurized intraperitoneal aerosol chemotherapy (PIPAC) in a postmortem swine model.

BACKGROUND: Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a novel approach delivering intraperitoneal chemotherapy by means of a pressurized aerosol. This study was conducted to evaluate the distribution pattern of doxorubicin in the abdominal cavity after PIPAC in a postmortem swine model. METHODS: Doxorubicin was aerosolized through a Micropump© (MIP) into the peritoneal cavity of two swines at a pressure of 12 mm Hg CO2 and 32 °C. To measure the distribution of the drug, 9 different positions within the abdominal cavity were sampled. In-tissue doxorubicin penetration was evaluated using fluorescence microscopy on frozen thin sections. RESULTS: A maximum of drug penetration was observed in the area around the MIP. The penetration in the small intestine reached a depth of 349 ± 65 µm. Penetration depth in the right upper abdomen and left upper abdomen were 349 ± 65 and 140 µm ± 26 µm, respectively. Distant areas to the MIP showed variable penetration rates between 50 and 150 µm. CONCLUSIONS: Doxorubicin reached all areas within the peritoneum. Highest penetration rates were measured in the area around the Micropump. Further studies are warranted to evaluate and optimize the distribution and penetration of cytotoxic agent into the tissue after PIPAC.

Irradiation Does Not Increase the Penetration Depth of Doxorubicin in Normal Tissue After Pressurized Intra-peritoneal Aerosol Chemotherapy (PIPAC) in an Ex Vivo Model.

AIM: To compare the impact of single fractional with bi-fractional irradiation on the depth of doxorubicin penetration into the normal tissue after pressurized intra-peritoneal aerosol chemotherapy (PIPAC) in our ex vivo model. MATERIALS AND METHODS: Fresh post mortem swine peritoneum was cut into 12 proportional sections. Two control samples were treated with PIPAC only (no irradiation), one sample on day 1, the other on day 2. Five samples were irradiated with 1, 2, 4, 7 or 14 Gy followed by PIPAC. Four samples were treated on day one with 0.5, 1, 2, 3.5 or 7 Gy and with the same radiation dose 24 h later followed by PIPAC. Doxorubicin was aerosolized in an ex vivo PIPAC model at 12 mmHg/36°C. In-tissue doxorubicin penetration was measured using fluorescence microscopy on frozen thin sections. RESULTS: Doxorubicin penetration (DP) after PIPAC for the control samples was 407 µm and 373 µm, respectively. DP for samples with single fraction irradiation was 396 µm after 1 Gy, 384 µm after 2 Gy, 327 µm after 4 Gy, 280 µm after 7 Gy and 243 µm after 14 Gy. DP for samples with 2 fractions of irradiation was 376 µm after 0.5+0.5 Gy, 363 µm after 1+1 Gy, 372 µm after 2+2 Gy, 341 µm after 3.5+3.5 and 301 µm after 7+7 Gy irradiation. Fractionating of the irradiation did not significantly change DP into normal tissue. CONCLUSION: Irradiation does not increase the penetration depth of doxorubicin into the normal tissue but might have a limiting impact on penetration and distribution of doxorubicin. Further studies are warranted to investigate the impact of addition of irradiation to PIPAC of tumor cells and to find out if irradiation can be used safely as chemopotenting agent for patients with peritoneal metastases treated with PIPAC.