In Vivo Feasibility of Electrostatic Precipitation as an Adjunct to Pressurized Intraperitoneal Aerosol Chemotherapy (ePIPAC)

Oxaliplatin-induced peripheral neurotoxicity in colorectal cancer patients: mechanisms, pharmacokinetics and strategies

Oxaliplatin-based chemotherapy is a standard treatment approach for colorectal cancer (CRC). However, oxaliplatin-induced peripheral neurotoxicity (OIPN) is a severe dose-limiting clinical problem that might lead to treatment interruption. This neuropathy may be reversible after treatment discontinuation. Its complicated mechanisms are related to DNA damage, dysfunction of voltage-gated ion channels, neuroinflammation, transporters, oxidative stress, and mitochondrial dysfunction, etc. Several strategies have been proposed to diminish OIPN without compromising the efficacy of adjuvant therapy, namely, combination with chemoprotectants (such as glutathione, Ca/Mg, ibudilast, duloxetine, etc.), chronomodulated infusion, dose reduction, reintroduction of oxaliplatin and topical administration [hepatic arterial infusion chemotherapy (HAIC), pressurized intraperitoneal aerosol chemotherapy (PIPAC), and hyperthermic intraperitoneal chemotherapy (HIPEC)]. This article provides recent updates related to the potential mechanisms, therapeutic strategies in treatment of OIPN, and pharmacokinetics of several methods of oxaliplatin administration in clinical trials.

Localized chemotherapy approaches and advanced drug delivery strategies: a step forward in the treatment of peritoneal carcinomatosis from ovarian cancer

Peritoneal carcinomatosis (PC) is a common outcome of epithelial ovarian carcinoma and is the leading cause of death for these patients. Tumor location, extent, peculiarities of the microenvironment, and the development of drug resistance are the main challenges that need to be addressed to improve therapeutic outcome. The development of new procedures such as HIPEC (Hyperthermic Intraperitoneal Chemotherapy) and PIPAC (Pressurized Intraperitoneal Aerosol Chemotherapy) have enabled locoregional delivery of chemotherapeutics, while the increasingly efficient design and development of advanced drug delivery micro and nanosystems are helping to promote tumor targeting and penetration and to reduce the side effects associated with systemic chemotherapy administration. The possibility of combining drug-loaded carriers with delivery via HIPEC and PIPAC represents a powerful tool to improve treatment efficacy, and this possibility has recently begun to be explored. This review will discuss the latest advances in the treatment of PC derived from ovarian cancer, with a focus on the potential of PIPAC and nanoparticles in terms of their application to develop new therapeutic strategies and future prospects.

Development of the Peritoneal Metastasis: A Review of Back-Grounds, Mechanisms, Treatments and Prospects

Peritoneal metastasis is a malignant disease which originated from several gastrointestinal and gynecological carcinomas and has been leading to a suffering condition in patients for decades. Currently, as people have gradually become more aware of the severity of peritoneal carcinomatosis, new molecular mechanisms for targeting and new treatments have been proposed. However, due to the uncertainty of influencing factors involved and a lack of a standardized procedure for this treatment, as well as a need for more clinical data for specific evaluation, more research is needed, both for preventing and treating. We aim to summarize backgrounds, mechanisms and treatments in this area and conclude limitations or new aspects for treatments.

Patient-reported outcomes during repetitive oxaliplatin-based pressurized intraperitoneal aerosol chemotherapy for isolated unresectable colorectal peritoneal metastases in a multicenter, single-arm, phase 2 trial (CRC-PIPAC)

BACKGROUND

CRC-PIPAC prospectively assessed repetitive oxaliplatin-based pressurized intraperitoneal aerosol chemotherapy (PIPAC-OX) as a palliative monotherapy (i.e., without concomitant systemic therapy in between subsequent procedures) for unresectable colorectal peritoneal metastases (CPM). The present study explored patient-reported outcomes (PROs) during trial treatment.

METHODS

In this single-arm phase 2 trial in two tertiary centers, patients with isolated unresectable CPM received 6-weekly PIPAC-OX (92 mg/m²). PROs (calculated from EQ-5D-5L, and EORTC QLQ-C30 and QLQ-CR29) were compared between baseline and 1 and 4 weeks after the first three procedures using linear mixed modeling with determination of clinical relevance (Cohen's D ≥ 0.50) of statistically significant differences.

RESULTS

Twenty patients underwent 59 procedures (median 3 [range 1-6]). Several PROs solely worsened 1 week after the first procedure (index value - 0.10, p < 0.001; physical functioning - 20, p < 0.001; role functioning - 27, p < 0.001; social functioning - 18, p < 0.001; C30 summary score - 16, p < 0.001; appetite loss + 15, p = 0.007; diarrhea + 15, p = 0.002; urinary frequency + 13, p = 0.004; flatulence + 13, p = 0.001). These PROs returned to baseline at subsequent time points. Other PROs worsened 1 week after the first procedure (fatigue + 23, p < 0.001; pain + 29, p < 0.001; abdominal pain + 32, p < 0.001), second procedure (fatigue + 20, p < 0.001; pain + 21, p < 0.001; abdominal pain + 20, p = 0.002), and third procedure (pain + 22, p < 0.001; abdominal pain + 22, p = 0.002). Except for appetite loss, all changes were clinically relevant. All analyzed PROs returned to baseline 4 weeks after the third procedure.

CONCLUSIONS

Patients receiving repetitive PIPAC-OX monotherapy for unresectable CPM had clinically relevant but reversible worsening of several PROs, mainly 1 week after the first procedure.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT03246321; Netherlands trial register: NL6426.

Primary and metastatic peritoneal surface malignancies

Peritoneal surface malignancies comprise a heterogeneous group of primary tumours, including peritoneal mesothelioma, and peritoneal metastases of other tumours, including ovarian, gastric, colorectal, appendicular or pancreatic cancers. The pathophysiology of peritoneal malignancy is complex and not fully understood. The two main hypotheses are the transformation of mesothelial cells (peritoneal primary tumour) and shedding of cells from a primary tumour with implantation of cells in the peritoneal cavity (peritoneal metastasis). Diagnosis is challenging and often requires modern imaging and interventional techniques, including surgical exploration. In the past decade, new treatments and multimodal strategies helped to improve patient survival and quality of life and the premise that peritoneal malignancies are fatal diseases has been dismissed as management strategies, including complete cytoreductive surgery embedded in perioperative systemic chemotherapy, can provide cure in selected patients. Furthermore, intraperitoneal chemotherapy has become an important part of combination treatments. Improving locoregional treatment delivery to enhance penetration to tumour nodules and reduce systemic uptake is one of the most active research areas. The current main challenges involve not only offering the best treatment option and developing intraperitoneal therapies that are equivalent to current systemic therapies but also defining the optimal treatment sequence according to primary tumour, disease extent and patient preferences. New imaging modalities, less invasive surgery, nanomedicines and targeted therapies are the basis for a new era of intraperitoneal therapy and are beginning to show encouraging outcomes.

Assessment of workplace environmental contamination and occupational exposure to cisplatin and doxorubicin aerosols during electrostatic pressurized intraperitoneal aerosol chemotherapy

BACKGROUND

Electrostatic precipitation pressurized intraperitoneal aerosol chemotherapy (ePIPAC) is a novel approach for intraperitoneal drug delivery. As ePIPAC using cisplatin and doxorubicin is performed in an operating room, the challenge is to safely deliver the chemotherapeutic aerosol intraperitoneally while preventing exposure to healthcare workers. The objective of this study was to describe cisplatin and doxorubicin workplace environmental contamination and healthcare worker exposure during ePIPAC.

METHODS

Antineoplastic drugs concentrations of cisplatin and doxorubicin were measured in wipe samples from the operating room, and urine samples were collected from healthcare workers. The air samples were collected in order to detect Cisplatin contamination. Cisplatin was analysed by inductively coupled plasma-mass spectrometry and doxorubicin by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry.

RESULTS

No trace of cisplatin was found in the air. Cisplatin and doxorubicin were detected on the operating room floor, surfaces, devices and personal protective equipment even after a cleaning protocol. No traces of cisplatin or doxorubicin were found in the urine samples.

CONCLUSION

In this study, no internal contamination was found in the ePIPAC surgical team even after implementing two successive ePIPAC procedures. These results showed the effectiveness of the individual and collective protective measures applied. However, the cleaning procedure during ePIPAC should be respected to limit environmental exposure to chemotherapy to cisplatin and doxorubicin during ePIPAC.

Pressurized intra-peritoneal aerosol chemotherapy (PIPAC): increased intraperitoneal pressure does not affect distribution patterns but leads to deeper penetration depth of doxorubicin in a sheep model

BACKGROUND

Pressurized Intra-Peritoneal Aerosol Chemotherapy (PIPAC) is an innovative treatment against peritoneal carcinomatosis. Doxorubicin is a common intra-venous chemotherapy used for peritoneal carcinomatosis and for PIPAC. This study evaluated the impact of increased PIPAC intraperitoneal pressure on the distribution and cell penetration of doxorubicin in a sheep model.

METHODS

Doxorubicin was aerosolized using PIPAC into the peritoneal cavity of 6 ewes (pre-alpes breed): N = 3 with 12 mmHg intraperitoneal pressure ("group 12") and N = 3 with 20 mmHg ("group 20"). Samples from peritoneum (N = 6), ovarian (N = 1), omentum (N = 1) and caecum (N = 1) were collected for each ewe. The number of doxorubicin positive cells was determined using the ratio between doxorubicine fluorescence-positive cell nuclei (DOXO+) over total number of DAPI positive cell nuclei (DAPI+). Penetration depth (μm) was defined as the distance between the luminal surface and the location of the deepest DOXO+ nuclei over the total number of cell nuclei that were stained with DAPI. Penetration depth (μm) was defined as the distance between the luminal surface and the location of the deepest DOXO+ nuclei.

RESULTS

DOXO+ nuclei were identified in 87% of samples. All omental samples, directly localized in front of the nebulizer head, had 100% DOXO+ nuclei whereas very few nuclei were DOXO+ for caecum. Distribution patterns were not different between the two groups but penetration depth in ovary and caecum samples was significantly deeper in group 20.

CONCLUSIONS

This study showed that applying a higher intra-peritoneal pressure during PIPAC treatment leads to a deeper penetration of doxorubicin in ovarian and caecum but does not affect distribution patterns.

The emergence of pressurized intraperitoneal aerosol chemotherapy as a palliative treatment option for patients with diffuse peritoneal metastases: a narrative review

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is an emerging palliative treatment for patients with unresectable peritoneal metastases. Potential advantages of PIPAC over current treatment options are a homogeneous intraperitoneal distribution, low local and systemic toxicity, and enhanced tumour penetration. Given these possible benefits, PIPAC is increasingly implemented in many centres worldwide. Scientific research into PIPAC is currently available from in vitro/in vivo/in animal studies, retrospective cohorts in humans, and phase I and II studies in humans. There are no results from randomised trials comparing PIPAC with conventional treatment, such as palliative systemic therapy. This narrative review aimed to provide an overview of the currently available literature on PIPAC. In general, repetitive PIPAC was feasible and safe for patients and operating room personnel. Primary and secondary non-access rates varied from 0-17% and 0-15%, respectively. Iatrogenic bowel injury was observed in 0-3% of PIPAC procedures. CTCAE grade 1-2 complications were common, mostly consisting of abdominal pain, nausea, vomiting, and fatigue. CTCAE grade 3-4 complications were uncommon, occurring on 0-15% of PIPAC procedures. Post-operative mortality rates of 0-2% were reported. The risk of occupational exposure to cytotoxic drugs was very low when strict safety guidelines were followed. Clinical heterogeneity was high in most studies, since, in general, patients with unresectable peritoneal metastases from a variety of primary tumours were included. Also, patients received either PIPAC monotherapy or PIPAC combined with concomitant systemic therapy, and were able to receive PIPAC in any line of palliative treatment. Since the results were generally not stratified for these three important factors, this severely complicates the interpretation of results. Based on the current literature, PIPAC may be regarded as a promising palliative treatment option in patients with diffuse peritoneal metastases. Initial results show that it is feasible and safe. However, well designed and (ideally) randomized controlled trials are urgently needed to determine the additional value of PIPAC in this setting. Until then, PIPAC should preferably be performed in the setting of clinical trials.

First-line palliative systemic therapy alternated with electrostatic pressurised intraperitoneal aerosol chemotherapy (oxaliplatin) for isolated unresectable colorectal peritoneal metastases: protocol of a multicentre, single-arm, phase II study (CRC-PIPAC-II)

INTRODUCTION

Despite its increasing use, first-line palliative systemic therapy alternated with electrostatic pressurised intraperitoneal aerosol chemotherapy with oxaliplatin (ePIPAC-OX), hereinafter referred to as first-line bidirectional therapy, has never been prospectively investigated in patients with colorectal peritoneal metastases (CPM). As a first step to address this evidence gap, the present study aims to assess the safety, feasibility, antitumour activity, patient-reported outcomes, costs and systemic pharmacokinetics of first-line bidirectional therapy in patients with isolated unresectable CPM.

METHODS AND ANALYSIS

In this single-arm, phase II study in two Dutch tertiary referral centres, 20 patients are enrolled. Key eligibility criteria are a good performance status, pathologically proven isolated unresectable CPM, no previous palliative systemic therapy for colorectal cancer, no (neo)adjuvant systemic therapy ≤6 months prior to enrolment and no previous pressurised intraperitoneal aerosol chemotherapy (PIPAC). Patients receive three cycles of bidirectional therapy. Each cycle consists of 6 weeks first-line palliative systemic therapy at the medical oncologists' decision (CAPOX-bevacizumab, FOLFOX-bevacizumab, FOLFIRI-bevacizumab or FOLFOXIRI-bevacizumab) followed by ePIPAC-OX (92 mg/m²) with an intraoperative bolus of intravenous leucovorin (20 mg/m2) and 5-fluorouracil (400 mg/m²). Study treatment ends after the third ePIPAC-OX. The primary outcome is the number of patients with-and procedures leading to-grade ≥3 adverse events (Common Terminology Criteria for Adverse Events V.5.0) up to 4 weeks after the last procedure. Key secondary outcomes include the number of bidirectional cycles in each patient, treatment-related characteristics, grade ≤2 adverse events, tumour response (histopathological, cytological, radiological, biochemical, macroscopic and ascites), patient-reported outcomes, systemic pharmacokinetics of oxaliplatin, costs, progression-free survival and overall survival.

ETHICS AND DISSEMINATION

This study is approved by the Dutch competent authority, a medical ethics committee and the institutional review boards of both study centres. Results will be submitted for publication in peer-reviewed medical journals and presented to patients and healthcare professionals.

TRIAL REGISTRATION NUMBER

NL8303.

Pharmaceutical strategies in improving anti-tumour efficacy and safety of intraperitoneal therapy for peritoneal metastasis

Introduction: In selected patients with limited peritoneal metastasis (PM), favorable tumor biology, and a good clinical condition, there is an indication for combination of cytoreductive surgery (CRS) and subsequent intravenous (IV) or intraperitoneal (IP) chemotherapy. Compared with IV injection, IP therapy can achieve a high drug concentration within the peritoneal cavity with low systemic toxicity, however, the clinical application of IP chemotherapy is limited by the related abdominal pain, infection, and intolerance.Areas covered:To improve the anti-tumor efficacy and safety of IP therapy, various pharmaceutical strategies have been developed and show promising potential. This review discusses the specialized modification of traditional drug delivery systems and demonstrates the preparation of customized drug carriers for IP therapy, including chemotherapy and gene therapy. IP therapy has important clinical significance in the treatment of PM using novel anti-tumor agents as well as conventional drugs in new applications.Expert opinion: Although IP therapy exhibits good performance both in mouse models and in patients with PM in clinical trials, its clinical application remains limited due to the serious side effects and low acceptability. Further investigations, including pharmaceutical strategies, are needed to develop potential IP therapy, focusing on the efficacy and safety thereof.

Pressurized intraperitoneal aerosol chemotherapy for recurrent ovarian, fallopian or primary peritoneal cancer with peritoneal carcinomatosis: a narrative review

For recurrent ovarian, fallopian or primary peritoneal cancer with peritoneal carcinomatosis (PC), it is challenging to resect tumors completely or to get complete remission by intravenous (IV) chemotherapy, and many patients show the resistance to various chemotherapeutic agents for IV chemotherapy ultimately. As an alternative, pressurized intraperitoneal aerosol chemotherapy (PIPAC) has been introduced for treating the disease, which delivers chemotherapeutic agents as an aerosol form while maintaining high intraperitoneal (IP) pressure. Based on preclinical studies, PIPAC showed better penetration depth and distribution of drugs into the peritoneum in comparison to conventional IP chemotherapy. Tumor regression on histology and peritoneal carcinomatosis index (PCI) has also been shown in relevant studies. In addition, most of the PIPAC procedures were completed successfully with acceptable toxicity due to the use of a low dose of chemotherapeutic agents. For considering these advantages of PIPAC, we review the current status of PIPAC for treating recurrent ovarian, fallopian or primary peritoneal cancer through literature review.

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for resectable peritoneal metastases is feasible in elderly patients

The aim is to evaluate the feasibility and the prognosis of cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) for resectable peritoneal metastases (RPM) in elderly patients. Patients who underwent CRS with HIPEC for RPM between 2012 and 2018 in one tertiary reference center were retrospectively included and divided according to the age: Group A (< 65 years) and Group B (≥ 65 years). Postoperative outcomes and survivals were compared. Ninety-five patients were included in Groups A (n = 65) and B (n = 30). The incidence of comorbidities was significantly higher in elderly patients (65 vs 90%, p = 0.01), but RPM characteristics were similar between groups. There was no difference between groups in terms of postoperative results: 30-day major morbidity (33 vs 23%, p = 0.4), 30-day mortality (0 vs 3%, p = 0.3), mean length of stay (26.7 ± 19.4 vs 22.4 ± 10.3 days, p = 0.3) and readmission's rate (15 vs 33%, p = 0.06). The only one significant difference was the 90-day mortality which never occurred before 65 years but in 10% of elderly patients (p = 0.03). There was no difference regarding recurrence's rate (56 vs 37%, p = 0.1), neither 1-, 3- and 5-year overall survival rates (86, 64 and 52% vs 85, 74% and not reached, p = 0.8) and disease-free survival rates (61, 28 and 28% vs 56, 45% and not reached, p = 0.6). CRS with HIPEC is feasible in elderly patients. Since the 90-day mortality appeared to be higher in elderly patients, additional criteria are necessary to improve the selection of elderly patients for this major surgery.

Pressurized Intraperitoneal Aerosol Chemotherapy (Oxaliplatin) for Unresectable Colorectal Peritoneal Metastases: A Multicenter, Single-Arm, Phase II Trial (CRC-PIPAC)

BACKGROUND

Despite its increasing use, pressurized intraperitoneal aerosol chemotherapy with oxaliplatin (PIPAC-OX) has never been prospectively investigated as a palliative monotherapy for colorectal peritoneal metastases in clinical trials. This trial aimed to assess the safety (primary aim) and antitumor activity (key secondary aim) of PIPAC-OX monotherapy in patients with unresectable colorectal peritoneal metastases.

METHODS

In this two-center, single-arm, phase II trial, patients with isolated unresectable colorectal peritoneal metastases in any line of palliative treatment underwent 6-weekly PIPAC-OX (92 mg/m²). Key outcomes were major treatment-related adverse events (primary outcome), minor treatment-related adverse events, hospital stay, tumor response (radiological, biochemical, pathological, ascites), progression-free survival, and overall survival.

RESULTS

Twenty enrolled patients underwent 59 (median 3, range 1-6) PIPAC-OX procedures. Major treatment-related adverse events occurred in 3 of 20 (15%) patients after 5 of 59 (8%) procedures (abdominal pain, intraperitoneal hemorrhage, iatrogenic pneumothorax, transient liver toxicity), including one possibly treatment-related death (sepsis of unknown origin). Minor treatment-related adverse events occurred in all patients after 57 of 59 (97%) procedures, the most common being abdominal pain (all patients after 88% of procedures) and nausea (65% of patients after 39% of procedures). Median hospital stay was 1 day (range 0-3). Response rates were 0% (radiological), 50% (biochemical), 56% (pathological), and 56% (ascites). Median progression-free and overall survival were 3.5 months (interquartile range [IQR] 2.5-5.7) and 8.0 months (IQR 6.3-12.6), respectively.

CONCLUSIONS

In patients with unresectable colorectal peritoneal metastases undergoing PIPAC-OX monotherapy, some major adverse events occurred and minor adverse events were common. The clinical relevance of observed biochemical, pathological, and ascites responses remains to be determined, especially since radiological response was absent.

Enhanced intraperitoneal delivery of charged, aerosolized curcumin nanoparticles by electrostatic precipitation

Aims: To investigate the potential of curcumin-loaded polylactic-co-glycolic acid nanoparticles (CUR-PLGA-NPs), alone and with electrostatic precipitation, for improving tissue uptake during pressurized intraperitoneal aerosol chemotherapy (PIPAC). Methods: Positively and negatively charged CUR-PLGA-NPs were delivered as PIPAC into inverted bovine urinary bladders ex vivo. The experiment was repeated with the additional use of electrostatic precipitation pressurized intraperitoneal aerosol chemotherapy (electrostatic PIPAC). Results: Positively charged CUR-PLGA-NPs increased depth of tissue penetration by 81.5% and tissue concentration by 80%. Electrostatic precipitation further improved the uptake of positively charged CUR-PLGA-NPs by 41.8%. Conclusion: The combination of positive charge and electrostatic precipitation have significant potential to improve tissue uptake of nanoparticles during intraperitoneal chemotherapy.

Experimental Model to Test Electrostatic Precipitation Technology in the COVID-19 Era: A Pilot Study

BACKGROUND

In the COVID-19 crisis, laparoscopic surgery is in focus as a relevant source of bioaerosol release. The efficacy of electrostatic aerosol precipitation (EAP) and continuous aerosol evacuation (CAE) to eliminate bioaerosols during laparoscopic surgery was verified.

STUDY DESIGN

Ex-vivo laparoscopic cholecystectomies (LCs) were simulated ± EAP or CAE in Pelvitrainer equipped with swine gallbladders. Release of bioaerosols was initiated by performing high-frequency electrosurgery with a monopolar electro hook (MP-HOOK) force at 40 watts (MP-HOOK40) and 60 watts (MP-HOOK60), as well as by ultrasonic cutting (USC). Particle number concentrations (PNC) of arising aerosols were analyzed with a condensation particle counter (CPC). Aerosol samples were taken within the Pelvitrainer close to the source, outside the Pelvitrainer at the working trocar, and in the breathing zone of the surgeon.

RESULTS

Within the Pelvitrainer, MP-HOOK40 (6.4 × 105 cm-3) and MP-HOOK60 (7.3 × 105 cm-3) showed significantly higher median PNCs compared to USC (4.4 × 105 cm-3) (p = 0.001). EAP led to a significant decrease of the median PNCs in all 3 groups. A high linear correlation with Pearson correlation coefficients of 0.852, 0.825, and 0.759 were observed by comparing MP-HOOK40 (± EAP), MP-HOOK60 (± EAP), and USC (± EAP), respectively. During ex-vivo LC and CAE, significant bioaerosol contaminations of the operating room occurred. Ex-vivo LC with EAP led to a considerable reduction of the bioaerosol concentration.

CONCLUSIONS

EAP was found to be efficient for intraoperative bioaerosol elimination and reducing the risk of bioaerosol exposure for surgical staff.

Pressurized Intraperitoneal Aerosol Chemotherapy Enhanced by Electrostatic Precipitation (ePIPAC) for Patients with Peritoneal Metastases

BACKGROUND

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a new mode of intraperitoneal chemotherapy administration that can potentially be improved by the addition of electrostatic precipitation (ePIPAC). This study aimed to describe the procedural details of ePIPAC and to analyze its safety for patients with nonresectable peritoneal metastasis as well as their tolerance and response to this treatment.

METHODS

This retrospective cohort study included consecutive patients treated with ePIPAC in three centers from April 2019 to April 2020. The toxicities of each patient were assessed using the Common Terminology Criteria for Adverse Events (CTCAE). Complications were documented according to the Clavien classification. Quality of life (QoL) was assessed using EORTC-QLQ-C30, and the peritoneal regression grading score (PRGS) was used to grade histologic responses. Further surrogates for responses were the Peritoneal Cancer Index (PCI), ascites, and symptoms.

RESULTS

Overall, 69 patients received 147 ePIPACs with oxaliplatin (n = 34) or cisplatin/doxorubicin (n = 35) mainly for colorectal (n = 25), ovarian (n = 14), and gastric (n = 13) primary cancers. Systemic chemotherapy was used in the treatment of 54 patients (76%). The median electrostatic therapy time was 12 min (range 6-30 min). The overall and major CTCAE toxicity rates were respectively 24.6% and 15.9%. The postoperative complications rate according to Clavien classification was 4.7%. The responses of 22 patients who had three or more ePIPAC treatments were evaluated as follows: PCI (16 vs 14; p = 0.4), ascites (320 vs 98 ml; p = 0.1), and PRGS (2.23 vs 1.73; p = 0.15). The complete (PRGS1) and major (PRGS2) histologic responses at the third ePIPAC were respectively 38.5% and 53.8%. Overall QoL was stable during the first ePIPACs.

CONCLUSION

Repetitive ePIPACs were safe and well tolerated for patients with unresectable peritoneal metastasis.

PIPAC versus HIPEC: cisplatin spatial distribution and diffusion in a swine model

Purpose: Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a novel approach for delivering intraperitoneal chemotherapy and offers perspective in the treatment of peritoneal carcinomatosis. Concept is based on a 12 mmHg capnoperitoneum loaded with drug changed in microdoplets. It was postulated to guarantee a more homogeneous drug distribution and tissular uptake than hyperthermic intraperitoneal chemotherapy (HIPEC). The aim of this study was to compare cisplatin peritoneal distribution and pharmacokinetic between HIPEC and PIPAC procedures in a healthy swine model.Methods: Two groups of eight pigs underwent either HIPEC with cisplatin (70 mg/m²) at 43 °C for 60 min, or PIPAC with cisplatin (7.5 mg/m²) for 30 min. Postoperatively, peritoneal areas were biopsied allowing peritoneal cavity cartography. Tissular and plasmatic cisplatin concentrations were analyzed.Results: Cisplatin distribution was heterogeneous in both the groups with higher concentrations obtained closed to the delivery sites. Median total platinum peritoneal concentration by pig was higher in the HIPEC group than in the PIPAC group (18.0 μg/g versus 4.3 μg/g, p < .001) but the yield was 2.2 times better with PIPAC. Platinum concentrations were higher in the HIPEC group in all stations. At each time-point, cisplatin plasmatic concentrations were higher in the HIPEC group (p < .001) but beneath the toxicity threshold.Conclusions: With doses used in clinical practice, HIPEC guaranteed a higher cisplatin peritoneal uptake than PIPAC in this swine model. Spatial drug distribution was heterogeneous with both technics, with hotspots closed to the drug delivery sites. Nevertheless, considering the dose ratio, IP drug uptake yield was better with PIPAC.

Restricted access to innovative surgical technique related to a specific training, is it ethical? Example of the PIPAC procedure. A systematic review and an experts survey

OBJECTIVE

Using the example of Pressurized Intra Peritoneal Aerosol Chemotherapy (PIPAC), we analyse the development model of this procedure and provide an ethical analysis of the involvement of the industry in a new development.

SUMMARY BACKGROUND DATA

In the case of breakthrough innovation, medical training is essential for safe use of the new procedure. In some cases, pharmaceutical companies decide to organise this training. But when it becomes the only training opportunity to use the device, scientists and clinicians could be exposed to a conflict of interest?

METHODS

We performed a literature review of PIPAC publications using the STROBE criteria. Then, we conducted interviews with an expert panel to analyse the ethical impact of involvement of the industry in the development of the PIPAC procedure.

RESULTS

The number of publications has increased every year since the first publication in Germany, where the technology was developed in 2013. The scientific production was of good quality, with a mean STROBE score of 18.2 ± 2.4 out of 22 points. Ten of the 33 included studies declared a conflict of interest. From the interviews, the main axe concerning the implication of the industry was the training model. The company had decided that only trained and approval surgeon could perform the PIPAC procedure. All four interviewed practitioners agreed that it was initially a good way to implement the procedure safely, but later they felt uncomfortable about the control and validation by the industry.

CONCLUSION

Based on the growing number of published papers from a growing number of international centres, the controlled training model is not limiting. However, the different levels of conflict of interest complicate transparency, and we postulated that this development model is limited to the beginning of the procedure diffusion. CLINICALTRIAL.

GOV REGISTRATION

NCT04341337.

Electrostatic Intraperitoneal Aerosol Delivery of Nanoparticles: Proof of Concept and Preclinical Validation

There is an increasing interest in intraperitoneal delivery of chemotherapy as an aerosol in patients with peritoneal metastasis. The currently used technology is hampered by inhomogenous drug delivery throughout the peritoneal cavity because of gravity, drag, and inertial impaction. Addition of an electrical force to aerosol particles, exerted by an electrostatic field, can improve spatial aerosol homogeneity and enhance tissue penetration. A computational fluid dynamics model shows that electrostatic precipitation (EP) results in a significantly improved aerosol distribution. Fluorescent nanoparticles (NPs) remain stable after nebulization in vitro, while EP significantly improves spatial homogeneity of NP distribution. Next, pressurized intraperitoneal chemotherapy with and without EP using NP albumin bound paclitaxel (Nab-PTX) in a novel rat model is examined. EP does not worsen the effects of CO₂ insufflation and intraperitoneal Nab-PTX on mesothelial structural integrity or the severity of peritoneal inflammation. Importantly, EP significantly enhances tissue penetration of Nab-PTX in the anatomical regions not facing the nozzle of the nebulizer. Also, the addition of EP leads to more homogenous peritoneal tissue concentrations of Nab-PTX, in parallel with higher plasma concentrations. In conclusion, EP enhances spatial homogeneity and tissue uptake after intraperitoneal nebulization of anticancer NPs.

Systemic Pharmacokinetics of Oxaliplatin After Intraperitoneal Administration by Electrostatic Pressurized Intraperitoneal Aerosol Chemotherapy (ePIPAC) in Patients with Unresectable Colorectal Peritoneal Metastases in the CRC-PIPAC Trial

BACKGROUND

Electrostatic pressurized intraperitoneal aerosol chemotherapy (ePIPAC) is a palliative treatment for unresectable peritoneal metastases from various primary cancers. However, little is known about the systemic pharmacokinetics of oxaliplatin after ePIPAC.

METHODS

Twenty patients with unresectable colorectal peritoneal metastases were treated with repetitive ePIPAC monotherapy with oxaliplatin (92 mg/m²) and a simultaneous intravenous bolus of leucovorin (20 mg/m²) and 5-fluorouracil (400 mg/m²). Samples were collected during each ePIPAC: whole blood at t = 0, t = 5, t = 10, t = 20, t = 30, t = 60, t = 120, t = 240, t = 360 and t = 1080 min for plasma and plasma ultrafiltrate concentrations; urine at t = 0, t = 1, t = 3, t = 5 and t = 7 days. Samples were analyzed using atomic absorption spectrometry. Pharmacokinetics were analyzed using nonlinear mixed-effects modeling.

RESULTS

Four patients received one ePIPAC, three patients received two ePIPAC, and thirteen patients received ≥ 3 ePIPAC. The population pharmacokinetic models adequately described the pharmacokinetics of oxaliplatin after ePIPAC. The plasma ultrafiltrate C_max of oxaliplatin reached 1.36-1.90 µg/mL after 30 min with an AUC_{0-24 h} of 9.6-11.7 µg/mL * h. The plasma C_max reached 2.67-3.28 µg/mL after 90 min with an AUC_{0-24 h} of 49.0-59.5 µg/mL * h. The absorption rate constant (Ka) was 1.13/h. Urine concentrations of oxaliplatin rapidly decreased to less than 3.60 µg/mL in 90% of the samples at day 7.

DISCUSSION

Systemic exposure to oxaliplatin after ePIPAC seemed comparable to that after systemic chemotherapy, as described in other literature. Since this is an indirect comparison, future research should focus on the direct comparison between the systemic exposure to oxaliplatin after ePIPAC and after systemic chemotherapy.

TRIAL REGISTRATION

NCT03246321, Pre-results; ISRCTN89947480, Pre-results; NTR6603, Pre-results; EudraCT: 2017-000927-29, Pre-results.

Safe management of surgical smoke in the age of COVID-19

Background

The COVID-19 global pandemic has resulted in a plethora of guidance and opinion from surgical societies. A controversial area concerns the safety of surgically created smoke and the perceived potential higher risk in laparoscopic surgery.

Methods

The limited published evidence was analysed in combination with expert opinion. A review was undertaken of the novel coronavirus with regards to its hazards within surgical smoke and the procedures that could mitigate the potential risks to healthcare staff.

Results

Using existing knowledge of surgical smoke, a theoretical risk of virus transmission exists. Best practice should consider the operating room set-up, patient movement and operating theatre equipment when producing a COVID-19 operating protocol. The choice of energy device can affect the smoke produced, and surgeons should manage the pneumoperitoneum meticulously during laparoscopic surgery. Devices to remove surgical smoke, including extractors, filters and non-filter devices, are discussed in detail.

Conclusion

There is not enough evidence to quantify the risks of COVID-19 transmission in surgical smoke. However, steps can be undertaken to manage the potential hazards. The advantages of minimally invasive surgery may not need to be sacrificed in the current crisis.

Pressurized intraperitoneal aerosol chemotherapy: a review of the introduction of a new surgical technology using the IDEAL framework

BACKGROUND

The IDEAL (Idea, Development, Evaluation, Assessment, Long-term study) framework is a scheme of investigation for innovative surgical therapeutic interventions. Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a procedure based on laparoscopy to deliver intraperitoneal chemotherapy for peritoneal metastases, introduced in 2011. The aim of this article was to review literature on PIPAC and assess whether development of the technique has followed the IDEAL framework.

METHODS

A search of MEDLINE and Embase was carried out to identify scientific reports on PIPAC published between January 2000 and February 2019. The studies were categorized according to the IDEAL stages.

RESULTS

Eighty-six original research papers on PIPAC were identified. There were 23 stage 0, 18 stage 1, 25 stage 2a and six stage 2b studies. Protocol papers for stage 1, 2b and 3 studies, and trial registrations for stage 2a studies, were also identified. The number of centres publishing reports and the number of publications has increased each year. Overall, there has been progression through the IDEAL stages; however, about 60 per cent of clinical reports published in 2018 were stage 1 Idea-type studies.

CONCLUSION

Since its introduction, studies investigating PIPAC have progressed in line with the IDEAL framework. However, the majority of studies reported recently were stage 0 and 1 studies.

Pressurized Intraperitoneal Aerosol Chemotherapy, a Palliative Treatment Approach for Patients With Peritoneal Carcinomatosis: Description of Method and Systematic Review of Literature

BACKGROUND

Peritoneal metastases arise in patients with a variety of primary cancers, and are associated with a poor prognosis. Systemic chemotherapy is the mainstay of treatment; however, the morbidity is considerable and the survival benefit is modest. Cytoreductive surgery and heated intraperitoneal chemotherapy is a potentially curative treatment available to a minority of patients; however, most develop recurrent disease. A novel palliative treatment for peritoneal metastases, pressurized intraperitoneal aerosol chemotherapy, has recently been introduced. Pressurized intraperitoneal aerosol chemotherapy utilizes an aerosol of chemotherapy in carbon dioxide gas. It is instilled into the abdomen under pressure via laparoscopic ports. No cytoreduction is performed. Pressurized intraperitoneal aerosol chemotherapy can be repeated at 6-week intervals. Oxaliplatin or cis-platinum and doxorubicin have been used to date.

OBJECTIVE

This study aims to systematically review and evaluate the method, and the preclinical and early clinical results of pressurized intraperitoneal aerosol chemotherapy.

DATA SOURCES

Medline and the Cochrane Library were the data sources for the study.

STUDY SELECTION

Peer-reviewed series of greater than 10 patients, with sufficient patient data, through April 2019, were selected.

INTERVENTION

Patients with peritoneal metastases underwent pressurized intraperitoneal aerosol chemotherapy.

MAIN OUTCOME MEASURES

Patient dropout, histologic tumor response, adverse events, and 30-day mortality were the primary outcomes measured.

RESULTS

A total of 921 patients with peritoneal metastases were brought to the operating room for pressurized intraperitoneal aerosol chemotherapy. The number of pressurized intraperitoneal aerosol chemotherapy treatments administered was as follows: 1 treatment, 862 (94%); 2 treatments, 645 (70%); and 3 treatments, 390 patients (42%). Initial laparoscopic access was not possible in 59 patients (6.4%). Common Terminology Criteria for Adverse Events grade 3 or higher were noted in 13.7% of the patients who, collectively, underwent a total of 2116 treatments. The 30-day mortality was 2.4% (22/921).

LIMITATIONS

This study was limited by the heterogeneity of reported data and primary tumor types and by the lack of long-term survival data.

CONCLUSIONS

Early clinical results are encouraging, but tumor-specific, prospective, randomized trials are needed to compare pressurized intraperitoneal aerosol chemotherapy to systemic chemotherapy. This method has yet to be introduced to the United States. It is another therapeutic option for patients with peritoneal metastases and will broaden the patient base for future clinical trials.

Intraperitoneal aerosolized drug delivery: Technology, recent developments, and future outlook

Current therapies for patients with peritoneal metastases (PM) are only moderately effective. Recently, a novel locoregional treatment method for PM was introduced, consisting of a combination of laparoscopy with intraperitoneal (IP) delivery of anticancer agents as an aerosol. This 'pressurized intraperitoneal aerosol chemotherapy' (PIPAC) may enhance tissue drug penetration by the elevated IP pressure during CO₂ capnoperitoneum. Also, repeated PIPAC cycles allow to accurately stage peritoneal disease and verify histological response to treatment. This review provides an overview of the rationale, indications, and currently used technology for therapeutic IP nebulization, and discusses the basic mechanisms governing aerosol particle transport and peritoneal deposition. We discuss early clinical results in patients with advanced, irresectable PM and highlight the potential of electrostatic aerosol precipitation. Finally, we discuss promising novel approaches, including nebulization of nanoparticles and prolonged release formulations.

Overcoming Drug Resistance by Taking Advantage of Physical Principles: Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC)

Theoretical considerations as well as comprehensive preclinical and clinical data suggest that optimizing physical parameters of intraperitoneal drug delivery might help to circumvent initial or acquired resistance of peritoneal metastasis (PM) to chemotherapy. Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) is a novel minimally invasive drug delivery system systematically addressing the current limitations of intraperitoneal chemotherapy. The rationale behind PIPAC is: (1) optimizing homogeneity of drug distribution by applying an aerosol rather than a liquid solution; (2) applying increased intraperitoneal hydrostatic pressure to counteract elevated intratumoral interstitial fluid pressure; (3) limiting blood outflow during drug application; (4) steering environmental parameters (temperature, pH, electrostatic charge etc.) in the peritoneal cavity for best tissue target effect. In addition, PIPAC allows repeated application and objective assessment of tumor response by comparing biopsies between chemotherapy cycles. Although incompletely understood, the reasons that allow PIPAC to overcome established chemoresistance are probably linked to local dose intensification. All pharmacological data published so far show a superior therapeutic ratio (tissue concentration/dose applied) of PIPAC vs. systemic administration, of PIPAC vs. intraperitoneal liquid chemotherapy, of PIPAC vs. Hyperthermic Intraperitoneal Chemotherapy (HIPEC) or PIPAC vs. laparoscopic HIPEC. In the initial introduction phase, PIPAC has been used in patients who were quite ill and had already failed multiple treatment regimes, but it may not be limited to that group of patients in the future. Rapid diffusion of PIPAC in clinical practice worldwide supports its potential to become a game changer in the treatment of chemoresistant isolated PM of various origins.

A real-time ex vivo model (eIBUB) for optimizing intraperitoneal drug delivery as an alternative to living animal models

BACKGROUND

Optimization of intraperitoneal drug delivery systems requires functional models. We proposed the Inverted Bovine Urinary Bladder Model (IBUB), but IBUB does not allow repeated measurements over time and there is a significant biological variability between organs.

METHODS

A further development of IBUB is presented, based on the physical principle of communicating vessels. Fresh bovine bladders were inverted so that the peritoneum lines up the inner surface. The IBUB and a second vessel were then interconnected under the same CO2 pressure and placed on two scales. The therapeutic solution (Doxorubicin 2.7 mg and Cisplatin 13.5 mg) was delivered via an aerosolizer. All experiments were in triplicate and blinded to the origin of samples, measurements in a GLP-certified laboratory.

RESULTS

The enhanced IBUB (eIBUB) model allows measurements of tissue drug concentration, depth of tissue penetration and spatial distribution. The homogeneous morphology of the peritoneum enables standardized, multiple tissue sampling. eIBUB minimizes biological variability between different bladders and eliminates the bias caused by the liquid collecting at the bottom of the model. Concentration of doxorubicin in the eIBUB (mean ± STDV: 18.5 ± 22.6 ng/mg) were comparable to clinical peritoneal biopsies (19.2 ± 38.6 ng/mg), as was depth of drug penetration (eIBUB: mean (min-max) 433 (381-486) µm, clinical ~ 500 µm).

CONCLUSIONS

The eIBUB model is a simple and powerful ex vivo model for optimizing intraperitoneal drug delivery and represents an attractive alternative to animal models. Results obtained are similar to those obtained in the human patient.

Pressurized IntraPeritoneal Aerosol Chemotherapy with one minute of electrostatic precipitation (ePIPAC) is feasible, but the histological tumor response in peritoneal metastasis is insufficient

INTRODUCTION

Electrostatic precipitation Pressurized IntraPeritoneal Aerosol Chemotherapy (ePIPAC) has shown superior penetration depth and tissue uptake compared to standard PIPAC. We investigated the feasibility and objective tumor response to ePIPAC with 1 min of precipitation in patients with peritoneal metastasis (PM).

MATERIALS AND METHODS

Patients with PM from various abdominal cancers were included in an amendment to the ongoing prospective PIPAC-OPC2 trial. Colorectal and appendiceal PM were treated with oxaliplatin, patients with PM from other primaries were treated with a combination of cisplatin and doxorubicin. Three ePIPAC procedures were planned in each patient including repeated peritoneal biopsies for response evaluation. After emission to the peritoneal cavity, the aerosolized chemotherapeutics were precipitated for 1 min followed by immediate exsufflation and abdominal closure. Histological regression from the first to the third ePIPAC was evaluated according to the Peritoneal Regression Grading Score (PRGS) and compared to data from the PIPAC-OPC1 trial. Complications and toxicities were recorded according to Dindo-Clavien and CTCAE.

RESULTS

Sixty-five ePIPAC procedures were performed in 33 patients (median 2, range 1-6). Ten patients were eligible for response evaluation based on biopsies from the first and third ePIPAC procedure. Four patients had disease progression, four patients had regressive disease, and two patients had stable disease according to PRGS. No life threatening adverse reactions and no mortality was observed following ePIPAC.

CONCLUSION

One minute ePIPAC was feasible and safe, but the histological tumor response was insufficient compared to standard PIPAC directed therapy with 30 min passive diffusion time.

Comparison of Tissue and Blood Concentrations of Oxaliplatin Administrated by Different Modalities of Intraperitoneal Chemotherapy

BACKGROUND

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a new technology for delivering intraperitoneal chemotherapy. It is generally assumed that with PIPAC, the ratio of peritoneal to systemic drug concentration is superior to liquid hyperthermic intraperitoneal chemotherapy (HIPEC). To date, no direct comparative data are available supporting such an assumption.

MATERIALS AND METHODS

Twelve 65-day-old pigs were randomly separated into three groups of four pigs each, all of which received intraperitoneal chemotherapy using the following administration methods: PIPAC with oxaliplatin 92 mg in 150 ml dextrose 5% (Group 1); PIPAC with electrostatic aerosol precipitation (ePIPAC; Group 2); or laparoscopic HIPEC (L-HIPEC) with oxaliplatin 400 mg in 4 L dextrose 5% at 42 °C (Group 3). Serial blood and peritoneal tissue concentrations of oxaliplatin were determined by spectrometry.

RESULTS

In all three groups, the maximum concentration of oxaliplatin in blood was detected 50-60 min after onset of the chemotherapy experiments, with no significant differences among the three groups (p = 0.7994). Blood oxaliplatin concentrations (0-30 min) were significantly higher in the L-HIPEC group compared with the ePIPAC group (p < 0.05). No difference was found for the overall systemic oxaliplatin absorption (area under the curve). Overall concentrations in the peritoneum were not different among the three groups (p = 0.4725), but were significantly higher in the visceral peritoneum in the PIPAC group (p = 0.0242).

CONCLUSIONS

Blood and tissue concentrations were comparable between all groups; however, depending on the intraperitoneal area examined and the time points of drug delivery, the concentrations differed significantly between the three groups.

Repetitive electrostatic pressurised intraperitoneal aerosol chemotherapy (ePIPAC) with oxaliplatin as a palliative monotherapy for isolated unresectable colorectal peritoneal metastases: protocol of a Dutch, multicentre, open-label, single-arm, phase II study (CRC-PIPAC)

INTRODUCTION

Repetitive electrostatic pressurised intraperitoneal aerosol chemotherapy with oxaliplatin (ePIPAC-OX) is offered as a palliative treatment option for patients with isolated unresectable colorectal peritoneal metastases (PM) in several centres worldwide. However, little is known about its feasibility, safety, tolerability, efficacy, costs and pharmacokinetics in this setting. This study aims to explore these parameters in patients with isolated unresectable colorectal PM who receive repetitive ePIPAC-OX as a palliative monotherapy.

METHODS AND ANALYSIS

This multicentre, open-label, single-arm, phase II study is performed in two Dutch tertiary referral hospitals for the surgical treatment of colorectal PM. Eligible patients are adults who have histologically or cytologically proven isolated unresectable PM of a colorectal or appendiceal carcinoma, a good performance status, adequate organ functions and no symptoms of gastrointestinal obstruction. Instead of standard palliative treatment, enrolled patients receive laparoscopy-controlled ePIPAC-OX (92 mg/m² body surface area (BSA)) with intravenous leucovorin (20 mg/m² BSA) and bolus 5-fluorouracil (400 mg/m² BSA) every 6 weeks. Four weeks after each procedure, patients undergo clinical, radiological and biochemical evaluation. ePIPAC-OX is repeated until disease progression, after which standard palliative treatment is (re)considered. The primary outcome is the number of patients with major toxicity (grade ≥3 according to the Common Terminology Criteria for Adverse Events v4.0) up to 4 weeks after the last ePIPAC-OX. Secondary outcomes are the environmental safety of ePIPAC-OX, procedure-related characteristics, minor toxicity, postoperative complications, hospital stay, readmissions, quality of life, costs, pharmacokinetics of oxaliplatin, progression-free survival, overall survival, and the radiological, histopathological, cytological, biochemical and macroscopic tumour response.

ETHICS AND DISSEMINATION

This study is approved by an ethics committee, the Dutch competent authority and the institutional review boards of both study centres. Results are intended for publication in peer-reviewed medical journals and for presentation to patients, healthcare professionals and other stakeholders.

TRIAL REGISTRATION NUMBER

NCT03246321, Pre-results; ISRCTN89947480, Pre-results; NTR6603, Pre-results; EudraCT: 2017-000927-29, Pre-results.

Aerosolization of Nanotherapeutics as a Newly Emerging Treatment Regimen for Peritoneal Carcinomatosis

Recent advances in locoregional chemotherapy have opened the door to new approaches for the clinical management of peritoneal carcinomatosis (PC) by facilitating the delivery of anti-neoplastic agents directly to the tumor site, while mitigating adverse effects typically associated with systemic administration. In particular, an innovative intra-abdominal chemotherapeutic approach, known as Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC), was recently introduced to the intraperitoneal (IP) therapy regimens as a palliative therapeutic option in patients with PC, presumably providing a better drug distribution pattern together with deeper drug penetration into tumor nodules within the peritoneal space. Furthermore, the progress of nanotechnology in the past few decades has prompted the application of different nanomaterials in IP cancer therapy, offering new possibilities in this field ranging from an extended retention time to sustained drug release in the peritoneal cavity. This review highlights the progress, challenges, and opportunities in utilizing cancer nanotherapeutics for locoregional drug delivery, with a special emphasis on the aerosolization approach for intraperitoneal therapies.

High Pressure Nebulization (PIPAC) Versus Injection for the Intraperitoneal Administration of mRNA Complexes

PURPOSE

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a novel technique delivering drugs into the abdominal cavity as an aerosol under high pressure. It is hypothesized to have advantages such as enhancing tissue uptake, distributing drugs homogeneously within the closed and expanded abdominal cavity and higher local concentration of drugs in the peritoneal cavity. However, the clinical trials of PIPAC so far are limited to liquid chemotherapeutic solution, and the applicability of biomolecules (such as mRNA, siRNA and oligonucleotide) is not known. We aimed to investigate the feasibility of administrating mRNA lipoplexes to the peritoneal cavity via high pressure nebulization.

METHODS

We firstly investigated the influences of nebulization on physicochemical properties and in vitro transfection efficiency of mRNA lipoplexes. Then, mRNA lipoplexes were delivered to healthy rats through intravenous injection, intraperitoneal injection and PIPAC, respectively.

RESULTS

mRNA lipoplexes can withstand the high pressure applied during the PIPAC procedure in vitro. Bioluminescence localized to the peritoneal cavity of rats after administration by IP injection and nebulization, while intravenous injection mainly induced protein expression in the spleen.

CONCLUSION

This study demonstrated that local nebulization is feasible to apply mRNA complexes in the peritoneal cavity during a PIPAC procedure.

Safety and preliminary efficacy of electrostatic precipitation during pressurized intraperitoneal aerosol chemotherapy (PIPAC) for unresectable carcinomatosis

INTRODUCTION

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) was recently introduced to treat unresectable peritoneal metastases. Adding an electrostatic field may enhance charged droplet precipitation and tissue penetration, resulting in improved anticancer efficacy. We report for the first time its safety and preliminary efficacy.

MATERIALS AND METHODS

Patients underwent PIPAC combined with an electrostatic field, using the Ultravision™ apparatus. Adverse events were scored with the Common Terminology Criteria. Treatment response was assessed after more than one PIPAC, using clinical symptoms, tumor markers, CT imaging and histological regression.

RESULTS

Forty-eight patients (median age, 61 y) with diverse primary tumors underwent 135 procedures (median per patient, 3). Most (65.2%) were treated as outpatient. Twenty-eight (58.3%) patients received concomitant chemotherapy. The most frequent treatment-related toxicities were anemia (grade 1 to 3, 13 [9.6%]), ileus (grade 1 to 3, 5 [3.7%]), anorexia (grade 1 to 3, 6 [4.4%]), nausea (grade 1 to 3, 5 [3.7%]) and vomiting (grade 1 to 3, 7 [5.2%]). There was no grade 4 or 5 morbidity. Twenty (41.7%) patients did not complete three treatments, mainly because of disease progression (n = 13). After two procedures, there were one responder and 8 non-responders. After three treatments, we observed 11 responders, two patients with stable disease, and 15 non-responders. All but one patient with therapy response received simultaneous chemotherapy.

CONCLUSION

Electrostatic precipitation during PIPAC is well tolerated and safe. After three procedures and concomitant chemotherapy, response or stable disease is achieved in approximately half of cases. These findings warrant prospective trials in homogeneous patient cohorts.

Establishment of a rat ovarian peritoneal metastasis model to study pressurized intraperitoneal aerosol chemotherapy (PIPAC)

BACKGROUND

pressurized intraperitoneal aerosol chemotherapy (PIPAC), with or without electrostatic precipitation (ePIPAC), was recently introduced in the treatment of peritoneal metastases (PM) from ovarian cancer (OC). Preliminary clinical data are promising, but several methodological issues as well the anticancer efficacy of PIPAC remain unaddressed. Here, we propose a rat ePIPAC model that allows to study these issues in a clinically relevant, reproducible, and high throughput model.

METHODS

laparoscopy and PIPAC were established in healthy Wistar rats. Aerosol properties were measured using laser diffraction spectrometry based granulometric analyses. Electrostatic precipitation was accomplished using a commercially available generator (Ultravision™). A xenograft model of ovarian PM was created in athymic rats using intraperitoneal (IP) injection of SKOV-3 luciferase positive cells. Tumor growth was monitored weekly by in vivo bioluminescence imaging.

RESULTS

PIPAC and electrostatic precipitation were well tolerated using a capnoperitoneum of 8 mmHg. All rats survived the (e)PIPAC procedure and no gas or aerosol leakage was observed over the entire procedure. With an injection pressure of 20 bar, granulometry showed a mean droplet diameter (D(v,0.5)) of 47 μm with a flow rate of 0.5 mL/s, and a significantly lower diameter (30 μm) when a flow rate of 0.8 mL/s was used. Experiments using IP injection of SKOV-3 luciferase positive cells showed that after IP injection of 20 × 10⁶ cells, miliary PM was observed in all animals. PIPAC was feasible and well supported in these tumor bearing animals.

CONCLUSIONS

we propose a reproducible and efficient rodent model to study PIPAC and ePIPAC in OC xenografts with widespread PM. This model allows to characterize and optimize pharmacokinetic and biophysical parameters, and to evaluate the anti-cancer efficacy of (e)PIPAC treatment.

Particle stability and structure on the peritoneal surface in pressurized intra-peritoneal aerosol chemotherapy (PIPAC) analysed by electron microscopy: First evidence of a new physical concept for PIPAC

Pressurized intra-peritoneal aerosol chemotherapy (PIPAC) has been introduced to the clinical setting as a novel approach for the treatment of peritoneal metastasis. The local interaction of chemoaerosol droplets with the peritoneal surface as well as their distribution pattern is considered the main advantage over conventional liquid intraperitoneal chemotherapy. The aim of the present study was to investigate the behavior of these aerosol particles during PIPAC application via electron microscopy. Solutions of doxycycline, liposomal doxorubicin and macrophage cells were aerosolized using an established ex-vivo model. PIPAC was performed on peritoneum samples via microcatheter (MC) at a pressure of 12 mmHg C0₂ at 27°C. Following PIPAC the surface structure of applied particles was measured via electron microscopy. The aerosol particle contact of doxycyclin created a nanofilm of ~200 nm height on the peritoneal surface, and this height was revealed to be independent of the size of the initial particle hitting. These nanofilm blocks of ‘cylinders’ are of different diameters depending on the initial aerosol particle hitting that spot. Diameters of these ‘cylinders’ are far wider than the original diameter of the initial aerosol particle. However, coated particles such as liposomal doxorubicin and macrophages remained intact following contact with the peritoneal surface. Based on this and other data, the concept that aerosol particles exhibit a gas-like behavior in the abdomen creating a therapeutic capnoperitoneum should be revised. Fluid aerosol particles collide with the peritoneum creating a nanofilm. The interaction of pressurized intraperitoneal aerosol on the peritoneum is therefore closer to the distribution of a liquid film than to that of a gas. Further studies are required to further analyze the interaction of this nanofilm on the peritoneum.

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) for peritoneal carcinomatosis: systematic review of clinical and experimental evidence with special emphasis on ovarian cancer

BACKGROUND

Systemic chemotherapy is not effective in patients with peritoneal carcinomatosis (PC) and only a minority of affected patients is eligible for cytoreductive surgery. Intraperitoneal chemotherapy may provide a therapy alternative for these patients.

METHODS

We performed a systematic review of clinical and experimental evidence on the safety and efficacy of pressurized intraperitoneal aerosol chemotherapy (PIPAC) in patients with PC and provide clinical recommendations based on the available evidence.

RESULTS

Fifty-eight reports were identified, categorized as experimental (18 reports), clinical (28 reports), and other articles (14 reports). Experimental studies demonstrated improved tissue penetration and peritoneal coverage. The 28 clinical studies reported on 3515 procedures in 1547 patients with PC of various primary tumors with 16 of these studies reporting on patients with ovarian cancer. Toxicity was manageable. Based on 1197 patients in 22 studies, adverse events CTCAE grades 1, 2, 3, 4, and 5 were observed in 537 (45%), 167 (14%), 83 (7%), 10 (0.8%), and 19 (1.6%) cases, respectively. In a pooled analysis, the objective tumor response rate was 69% and the mean overall survival duration was 13.7 months. No significant hepatic, renal, or hematologic toxicity was described. PIPAC maintained and/or improved quality of life, as reported in 10 studies with 396 patients.

CONCLUSIONS

Available evidence from controlled trials (phase I and phase II) and retrospective cohort studies in > 1500 patients unequivocally demonstrates that PIPAC is feasible, safe, and effective. PIPAC maintains quality of life in patients with recurrent cancer and PC. PIPAC is as evidence-based as any other treatment in women with ovarian cancer and PC beyond the third line of systemic chemotherapy and can be recommended in this indication.

Concentrations of cisplatin and doxorubicin in ascites and peritoneal tumor nodules before and after pressurized intraperitoneal aerosol chemotherapy (PIPAC) in patients with peritoneal metastasis

INTRODUCTION

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a new means of delivering chemotherapy into the abdomen of patients with peritoneal carcinomatosis (PC). The amount of drug uptake in ascites and peritoneum after PIPAC is unknown.

METHODS

Retrospective cohort study of women with PC from gynecological tumors comparing the concentrations of cisplatin and doxorubicin in ascites and peritoneum before and after PIPAC. Concentrations were measured using gas chromatography. Peritoneal tumor samples were assessed for histological tumor regression.

RESULTS

59 PIPAC procedures were performed in 32 women with PC. The concentrations of doxorubicin and cisplatin in ascites significantly increased after PIPAC (140.2 ± 671.5 vs 9035.7 ± 5328.6 ng/ml; p < 0.0001 and 95.2 ± 106.4 vs 24,770.8 ± 11,710.8 ng/ml; p < 0.0001, respectively). Concentrations of doxorubicin and cisplatin in peritoneal tissue also significantly increased after PIPAC (5.1 ± 0.7 vs 19.2 ± 38.6 ng/g; p = 0.007, and 81.9 ± 7.8 vs 131.5 ± 134.4 ng/g; p = 0.005, respectively). On an individual patient level, a significant uptake (>2-fold) of doxorubicin and cisplatin was observed in 57/59 (97%) and 58/59 (98%) of cases in ascites and in 23/59 (39%) and 13/59 (22%) of cases in the peritoneum. Uptake of cisplatin and doxorubicin were significantly correlated (Spearman correlation coefficient: 0.33; p = 0.011). After repeated PIPACs, doxorubicin uptake increased in peritoneal tumor tissue (p = 0.008).

CONCLUSIONS

PIPAC leads to a significant chemotherapy uptake in both ascites and peritoneum, suggesting a bimodal cytotoxic effect of PIPAC via direct tissue uptake into peritoneal tumor nodules and via ascites. Consecutive PIPAC applications lead to peritoneal accumulation of doxorubicin, suggesting a cumulative cytotoxic effect of doxorubicin after repeated PIPACs.

The use of PIPAC (pressurized intraperitoneal aerosol chemotherapy) in gynecological oncology: a statement by the "Arbeitsgemeinschaft Gynaekologische Onkologie Studiengruppe Ovarialkarzinom (AGO-OVAR)", the Swiss and Austrian AGO, and the North-Eastern German Society of Gynaecologic Oncology

BACKGROUND

Ovarian, tubal, and peritoneal carcinomas primarily affect the peritoneal cavity, and they are typically diagnosed at an advanced tumor stage (Foley, Rauh-Hain, del Carmen in Oncology (Williston Park) 27:288-294, 2013). In the course of primary surgery, postoperative tumor residuals are, apart from the tumor stage, the strongest independent factors of prognosis (du Bois, Reuss, Pujade-Lauraine, Harter, Ray-Coquard, Pfisterer in Cancer 115:1234-1244, 2009). Due to improved surgical techniques, including the use of multi-visceral procedures, macroscopic tumor clearance can be achieved in oncological centers, in most cases (Harter, Muallem, Buhrmann et al in Gynecol Oncol 121:615-619, 2011). However, to date, it has not been shown that peritoneal carcinomatosis is, per se, an independent factor of prognosis or that it excludes the achievement of tumor clearance. Several studies have shown that a preceding drug therapy in peritoneal carcinomatosis could positively influence the overall prognosis (Trimbos, Trimbos, Vergote et al in J Natl Cancer Inst 95:105-112, 2003). In relapses of ovarian carcinoma, studies have shown that peritoneal carcinomatosis is a negative predictor of complete tumor resection; however, when it is possible to resect the tumor completely, peritoneal carcinomatosis does not play a role in the prognosis (Harter, Hahmann, Lueck et al in Ann Surg Oncol 16:1324-1330, 2009).

RESULTS

PIPAC is a highly experimental method for treating patients with ovarian, tubal, and peritoneal cancer. To date, only three studies have investigated a total of 184 patients with peritoneal carcinomatosis (Grass, Vuagniaux, Teixeira-Farinha, Lehmann, Demartines, Hubner in Br J Surg 104:669-678, 2017). Only some of those studies were phase I/II studies that included PIPAC for patients with different indications and different cancer entities. It is important to keep in mind that the PIPAC approach is associated with relatively high toxicity. To date, no systematic dose-finding studies have been reported. Moreover, no studies have reported improvements in progression-free or overall survival associated with PIPAC therapy.

CONCLUSIONS

Randomized phase III studies are required to evaluate the effect of this therapy compared to other standard treatments (sequential or simultaneous applications with systemic chemotherapy). In cases of ovarian, tubal, and peritoneal cancer, PIPAC should not be performed outside the framework of prospective, controlled studies.

Hyperthermic intracavitary nanoaerosol therapy (HINAT) as an improved approach for pressurised intraperitoneal aerosol chemotherapy (PIPAC): Technical description, experimental validation and first proof of concept

Background: The delivery of aerosolised chemotherapeutic substances into pressurised capnoperitonea has been reported to be more effective than conventional liquid chemotherapy for the treatment of peritoneal carcinomatosis. However, recent reports reveal limitations of the currently available technology. Material and Methods: A novel approach for pressurised intraperitoneal aerosol chemotherapy (PIPAC), called hyperthermic intracavitary nanoaerosol therapy (HINAT), based on extracavitary generation of hyperthermic and unipolar charged aerosols, was developed. The aerosol size distribution, the spatial drug distribution and in-tissue depth penetration of HINAT were studied by laser diffraction spectrometry, differential electrical mobility analysis, time of flight spectrometry, scintigraphic peritoneography and fluorescence microscopy. All experiments were performed contemporaneous with conventional PIPAC for the purpose of comparison. Furthermore, a first proof of concept was simulated in anesthetised German Landrace pigs. Results: HINAT provides a nanometre-sized (63 nm) unipolar-charged hyperthermic (41 °C) drug aerosol for quasi uniform drug deposition over the whole peritoneum with significantly deeper drug penetration than that offered by conventional PIPAC.

Occupational safety of pressurized intraperitoneal aerosol chemotherapy (PIPAC)

BACKGROUND

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) has emerged as a novel method to treat extensive, small volume peritoneal metastases. The clinical use of chemotherapy containing aerosols represents a potential occupational health hazard. We report the results of toxicological analysis during the first two clinical PIPAC procedures performed at Ghent University Hospital.

METHODS

After extensive preparation and in vitro testing, two patients were treated with PIPAC: the first using doxorubicin (2.86 mg in 51.43 mL) and cisplatin (14.28 mg in 164.3 mL), the second using oxaliplatin (182.10 mg in 186.42 mL). A standardized safety checklist was developed and used. Aerosol delivery was combined with electrostatic precipitation (ePIPAC). The following samples were obtained at several time points and locations: environmental air, floor surface wipes, surgeon's gloves, surgeon's hand wipes, circuit filters, and fluid from the water seal collection chamber container placed along the closed aerosol waste evacuating line. Platinum concentration was measured in these samples using voltammetry. Sample collection and analysis were performed by an independent external laboratory.

RESULTS

Platinum was not detected on the four floor locations after both procedures (detection limit 0.02 ng/cm2). Similarly, no platinum was detected in environmental air during both PIPACs at the surgeon's or anesthesiologist's position (detection limit 4.0-27 ng/m3). No platinum contamination was detected on the hands, outer pair of gloves, or inner pair of gloves of the surgeon (detection limit 70 and 50 ng respectively). Platinum was not detected on the filters and in the air-seal container liquid.

CONCLUSIONS

With adequate preparation and precautions, a clinical PIPAC program can be established without measurable chemotherapy exposure to the operating room environment or healthcare workers.

Scintigraphic peritoneography reveals a non-uniform 99mTc-Pertechnetat aerosol distribution pattern for Pressurized Intra-Peritoneal Aerosol Chemotherapy (PIPAC) in a swine model

BACKGROUND

Although recent data are contradictory, it is still claimed that Pressurized Intra-Peritoneal Aerosol Chemotherapy (PIPAC) would deliver an aerosol which distributes homogeneously throughout the entire abdominal cavity.

METHODS

^99mTc-Pertechnetat was administered in four postmortem swine using either PIPAC or liquid intra-peritoneal chemotherapy (IPC). The animals were examined by planar scintigraphy and SPECT/CT. Planar distribution images were divided into four regions of interest (ROIs: right/left upper and lower abdominal quadrant). SPECT/CT slices were scanned for areas of intense nuclide accumulation ("hot spots"). The percentage of relative distribution for planar scintigraphy was calculated by dividing the summed individual counts of each ROI by total counts measured in the entire abdominal cavity. The relative distribution of the "hot spots" was analyzed by dividing the counts of the local volume of interest (VOI) by the summed volume counts measured in the entire abdominal cavity.

RESULTS

In all four animals, planar scintigraphy showed inhomogeneous nuclide distribution. After PIPAC only 8-10% of the delivered nuclide was detected in one ROI with a mean deviation of 40% and 74% from a uniform nuclide distribution pattern. In all animals, SPECT/CT revealed "hot spots" beneath the PIPAC Micropump, catheter tip, and in the cul-de-sac region which comprise about 25% of the total amount of delivered nuclide in 2.5% of the volume of the entire abdominal cavity.

CONCLUSIONS

Our present data indicate that the intra-abdominal aerosol distribution pattern of PIPAC therapy is non-homogeneous and that the currently applied technology has still not overcome the problem of inhomogeneous drug distribution of IPC.

Systematic review of pressurized intraperitoneal aerosol chemotherapy for the treatment of advanced peritoneal carcinomatosis

BACKGROUND

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a minimally invasive approach under investigation as a novel treatment for patients with peritoneal carcinomatosis of various origins. The aim was to review the available evidence on mechanisms, clinical effects and risks.

METHODS

This was a systematic review of the literature on pressurized intraperitoneal chemotherapy published between January 2000 and October 2016. All types of scientific report were included.

RESULTS

Twenty-nine relevant papers were identified; 16 were preclinical studies and 13 were clinical reports. The overall quality of the clinical studies was modest; five studies were prospective and there was no randomized trial. Preclinical data suggested better distribution and higher tissue concentrations of chemotherapy agents in PIPAC compared with conventional intraperitoneal chemotherapy by lavage. Regarding technical feasibility, laparoscopic access and repeatability rates were 83-100 and 38-82 per cent. Surgery-related complications occurred in up to 12 per cent. Postoperative morbidity was low (Common Terminology Criteria for Adverse Events grade 3-5 events reported in 0-37 per cent), and hospital stay was about 3 days. No negative impact on quality of life was reported. Histological response rates for therapy-resistant carcinomatosis of ovarian, colorectal and gastric origin were 62-88, 71-86 and 70-100 per cent respectively.

CONCLUSION

PIPAC is feasible, safe and well tolerated. Preliminary good response rates call for prospective analysis of oncological efficacy.

A new ex vivo model for optimizing distribution of therapeutic aerosols: the (inverted) bovine urinary bladder

Background

Development of Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC) requires adequate preclinical models.

Methods

The model should be easy to use, reproducible and cost-effective. It should have a volume similar to the human abdominal cavity, and an oval shape. The inner surface should be lined with serosa. The model should allow pharmacological and biological analysis, including histology. No living animals should be used.

Results

The fresh urinary bladder is explanted from an adult bovine in the slaughterhouse. A 4-cm incision is performed into the bladder neck. The bladder can be inverted through the incision, which allows exposition of the serosa on its inner side. A balloon trocar is inserted through the incision and a ligature placed, ensuring full tightness. The therapeutic capnoperitoneum is installed. The bovine bladder has a volume somewhat smaller (2-3 L) than the human abdominal cavity (3-5 L). Costs are minimal. There is no significant bacteriological contamination. Manipulation is simple.

Conclusions

The (inverted) bovine urinary bladder is an innovative and versatile ex vivo model for optimizing drug delivery with therapeutic aerosols both onto the mucosa or the serosa. This model can be used for pharmaceutical Quality-by-Design approaches and will replace a large number of experiments in the animal.

Pharmacokinetic problems in peritoneal drug administration: an update after 20 years

Intraperitoneal chemotherapy has demonstrated significant pharmacologic and clinical advantage over traditional intravenous administration for cancers that are restricted to the peritoneal cavity. The combination of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) has become the standard technique used to fight ovarian and gastrointestinal cancers in many centers. However, challenges remain for HIPEC to contact the entire peritoneal surface, penetrate the tumor tissue, and transport to the lymphatics and other metastatic sites. New innovations in delivery technique, such as heated aerosol, and in delivery molecules, such as microparticles, nanoparticles, nanogels, and tumor-penetrating peptides are being tested in animal models and will likely soon be in human trials. Improvements in overall care, such as the recent clinical trial of an oral agent for maintenance therapy in ovarian carcinoma, will continue in this field for the next 20 years.

Environmental safety during the administration of Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC)

Background

Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC) is an innovative technique for intraperitoneal drug delivery. This study investigates the efficacy of the occupational health safety measures taken to prevent exposition of healthcare workers to the toxic chemotherapy aerosol.

Methods

Air samples were taken at the working place of the surgeon and of the anesthetist during 2 PIPAC procedures and analyzed for content of platinum by inductively coupled plasma mass spectrometry (ICP-MS). Airborne particles were quantified in real time. Biological monitoring was performed in two surgeons after 50 PIPAC by examining blood samples for possible traces of platinum. Analysis was performed by an independent company.

Results

Safety measures included tightly closed abdomen, operating room (OR), ventilation meeting requirements of ISO norm 14644-1 class 5, closed aerosol waste system and remote control of PIPAC administration. No traces of platinum were found in the air of the OR (detection limit of 0.0001 mg/filter). No specific rise in particle concentration was detected in the air during the PIPAC procedure, patient closure and removal of the sterile drapes. Blood samples of the surgeons showed no traces of platinum.

Conclusions

After implementation of adequate safety measures, no signs of environmental contamination or biological exposure of the surgeons were detected during PIPAC.

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.