Photodynamic therapy as an innovative treatment for malignant pleural mesothelioma

Targeting Glioblastoma-Associated Macrophages for Photodynamic Therapy Using AGuIX®-Design Nanoparticles

Glioblastoma (GBM) is the most difficult brain cancer to treat, and photodynamic therapy (PDT) is emerging as a complementary approach to improve tumor eradication. Neuropilin-1 (NRP-1) protein expression plays a critical role in GBM progression and immune response. Moreover, various clinical databases highlight a relationship between NRP-1 and M2 macrophage infiltration. In order to induce a photodynamic effect, multifunctional AGuIX^®-design nanoparticles were used in combination with a magnetic resonance imaging (MRI) contrast agent, as well as a porphyrin as the photosensitizer molecule and KDKPPR peptide ligand for targeting the NRP-1 receptor. The main objective of this study was to characterize the impact of macrophage NRP-1 protein expression on the uptake of functionalized AGuIX^®-design nanoparticles in vitro and to describe the influence of GBM cell secretome post-PDT on the polarization of macrophages into M1 or M2 phenotypes. By using THP-1 human monocytes, successful polarization into the macrophage phenotypes was argued via specific morphological traits, discriminant nucleocytoplasmic ratio values, and different adhesion abilities based on real-time cell impedance measurements. In addition, macrophage polarization was confirmed via the transcript-level expression of TNFα, CXCL10, CD-80, CD-163, CD-206, and CCL22 markers. In relation to NRP-1 protein over-expression, we demonstrated a three-fold increase in functionalized nanoparticle uptake for the M2 macrophages compared to the M1 phenotype. The secretome of the post-PDT GBM cells led to nearly a three-fold increase in the over-expression of TNFα transcripts, confirming the polarization to the M1 phenotype. The in vivo relationship between post-PDT efficiency and the inflammatory effects points to the extensive involvement of macrophages in the tumor zone.

Evaluation of Detector Position and Light Fluence Distribution Using an Infrared Navigation System during Pleural Photodynamic Therapy†

Photodynamic therapy (PDT) has been used to treat malignant pleural mesothelioma. Current practice involves delivering light to a prescribed light fluence with a point source, monitored by eight isotropic detectors inside the pleural cavity. An infrared (IR) navigation system was used to track the location of the point source throughout the treatment. The recorded data were used to reconstruct the pleural cavity and calculate the light fluence to the whole cavity. An automatic algorithm was developed recently to calculate the detector positions based on recorded data within an hour. This algorithm was applied to patient case studies and the calculated results were compared to the measured positions, with an average difference of 2.5 cm. Calculated light fluence at calculated positions were compared to measured values. The differences between the calculated and measured light fluence were within 14% for all cases, with a fixed scattering constant and a dual correction method. Fluence-surface histogram (FSH) was calculated for photofrin-mediated PDT to be able to cover 80% of pleural surface area to 50 J cm-2 (83.3% of 60 J cm-2 ). The study demonstrates that it will be possible to eliminate the manual measurement of the detector positions, reducing the patient's time under anesthesia.

TLD1433-Mediated Photodynamic Therapy with an Optical Surface Applicator in the Treatment of Lung Cancer Cells In Vitro

Intra-operative photodynamic therapy (IO-PDT) in combination with surgery for the treatment of non-small cell lung cancer and malignant pleural mesothelioma has shown promise in improving overall survival in patients. Here, we developed a PDT platform consisting of a ruthenium-based photosensitizer (TLD1433) activated by an optical surface applicator (OSA) for the management of residual disease. Human lung adenocarcinoma (A549) cell viability was assessed after treatment with TLD1433-mediated PDT illuminated with either 532- or 630-nm light with a micro-lens laser fiber. This TLD1433-mediated PDT induced an EC50 of 1.98 μM (J/cm2) and 4807 μM (J/cm2) for green and red light, respectively. Cells were then treated with 10 µM TLD1433 in a 96-well plate with the OSA using two 2-cm radial diffusers, each transmitted 532 nm light at 50 mW/cm for 278 s. Monte Carlo simulations of the surface light propagation from the OSA computed light fluence (J/cm2) and irradiance (mW/cm2) distribution. In regions where 100% loss in cell viability was measured, the simulations suggest that >20 J/cm2 of 532 nm was delivered. Our studies indicate that TLD1433-mediated PDT with the OSA and light simulations have the potential to become a platform for treatment planning for IO-PDT.

Light Fluence Rate and Tissue Oxygenation (St O2 ) Distributions Within the Thoracic Cavity of Patients Receiving Intraoperative Photodynamic Therapy for Malignant Pleural Mesothelioma

The distributions of light and tissue oxygenation (S_t O₂ ) within the chest cavity were determined for 15 subjects undergoing macroscopic complete resection followed by intraoperative photodynamic therapy (PDT) as part of a clinical trial for the treatment of malignant pleural mesothelioma (MPM). Over the course of light delivery, detectors at each of eight different sites recorded exposure to variable fluence rate. Nevertheless, the treatment-averaged fluence rate was similar among sites, ranging from a median of 40-61 mW cm^-2 during periods of light exposure to a detector. S_t O₂ at each tissue site varied by subject, but posterior mediastinum and posterior sulcus were the most consistently well oxygenated (median S_t O₂ >90%; interquartile ranges ~85-95%). PDT effect on S_t O₂ was characterized as the S_t O₂ ratio (post-PDT S_t O₂ /pre-PDT S_t O₂ ). High S_t O₂ pre-PDT was significantly associated with oxygen depletion (S_t O₂ ratio < 1), although the extent of oxygen depletion was mild (median S_t O₂ ratio of 0.8). Overall, PDT of the thoracic cavity resulted in moderate treatment-averaged fluence rate that was consistent among treated tissue sites, despite instantaneous exposure to high fluence rate. Mild oxygen depletion after PDT was experienced at tissue sites with high pre-PDT S_t O₂ , which may suggest the presence of a treatment effect.

Surgery for malignant pleural mesothelioma: an international guidelines review

Currently there is no universally accepted surgical therapy for malignant pleural mesothelioma (MPM). The goal of surgery in this dismal disease is a macroscopic complete resection (MCR) and there are two types of intervention with a curative intent. At one side, there is the extrapleural pneumonectomy (EPP) which consists in an en-bloc resection of the lung, pleura, pericardium and diaphragm and at the other side, there is pleurectomy/decortication (P/D) a lung-sparing surgery. Initially, EPP was considered the only surgical option with a curative aim, but during the decades P/D have acquired a role of increasing importance in MPM therapy. Several randomized prospective trials are required to establish the best strategy in the treatment of pleural mesothelioma. Although which is the best surgical option remains unclear, the International Mesothelioma Interest Group (IMIG), recently have stated that the type of surgery depends on clinical factors and on individual surgical judgment and expertise. Moreover, according to the current evidence, the surgery should be performed in high-volume centres within multimodality protocols. The aim of this study is to examine the currently available international guidelines in the surgical diagnosis and treatment of MPM.

[Intraperitoneal photodynamic therapy for peritoneal metastasis of epithelial ovarian cancer. Limits and future prospects]

High peritoneal recurrence rate in advanced epithelial ovarian cancer after complete macroscopic cytoreductive surgery and platinum-based chemotherapy, raises the issue of peritoneal microscopic disease management and requires the development of additional locoregional treatment strategies. Photodynamic therapy is an effective treatment already applied in other medical and surgical indications. After administration of a photosensitizer which accumulates in cancer cells, illumination with a light of adequate wavelength may induce photochemical reaction between photosensitizer and tissue oxygen which lead to reactive oxygen species production and cytotoxic phenomenon. Photodynamic therapy's ability to treat superficial lesions disseminated on large area makes it an excellent candidate to insure destruction of microscopic peritoneal metastases in addition to macroscopic cytoreductive surgery in order to decrease peritoneal recurrence rate. Development of intraperitoneal photodynamic therapy has been limited by its poor tolerance related to the lack of specificity of photosensitizers and the location of the metastases in proximity to adjacent intraperitoneal organs. Our aim is to review clinical data concerning intraperitoneal photodynamic therapy and epithelial ovarian cancer to identify the limits of this strategy and to provide solutions which may be applied to solve these barriers and enable safe and effective treatment. Targeted photosensitizers and innovative illumination solutions are mandatory to continue research in this field and to consider the feasibility of clinical trials.

Extended Pleurectomy-Decortication-Based Treatment for Advanced Stage Epithelial Mesothelioma Yielding a Median Survival of Nearly Three Years

BACKGROUND

The purpose of this study was to assess survival for patients with malignant pleural mesothelioma (MPM), epithelial subtype, utilizing extended pleurectomy-decortication combined with intraoperative photodynamic therapy (PDT) and adjuvant pemetrexed-based chemotherapy.

METHODS

From 2005 to 2013, 90 patients underwent lung-sparing surgery and PDT for MPM. All patients had a preoperative diagnosis of epithelial subtype, of which 17 proved to be of mixed histology. The remaining 73 patients with pure epithelial subtype were analyzed. All patients received lung-sparing surgery and PDT; 92% also received chemotherapy. The median follow-up was 5.3 years for living patients.

RESULTS

Macroscopic complete resection was achieved in all 73 patients. Thirty-day mortality was 3% and 90-day mortality was 4%. For all 73 patients (89% American Joint Commission on Cancer stage III/IV, 69% N2 disease, median tumor volume 550 mL), the median overall and disease-free survivals were 3 years and 1.2 years, respectively. For the 19 patients without lymph node metastases (74% stage III/IV, median tumor volume 325 mL), the median overall and disease-free survivals were 7.3 years and 2.3 years, respectively.

CONCLUSIONS

This is a mature dataset for MPM that demonstrates the ability to safely execute a complex treatment plan that included a surgical technique that consistently permitted achieving a macroscopic complete resection while preserving the lung. The role for lung-sparing surgery is unclear but this series demonstrates that it is an option, even for advanced cases. The overall survival of 7.3 years for the node negative subset of patients, still of advanced stage, is encouraging. Of particular interest is the overall survival being approximately triple the disease-free survival, perhaps PDT related. The impact of PDT is unclear, but it is hoped that it will be established by an ongoing randomized trial.

Illumination profile characterization of a light device for the dosimetry of intra-pleural photodynamic therapy for mesothelioma

BACKGROUND

Complete and homogeneous illumination of the pleural cavity is essential to the success of photodynamic therapy (PDT) for mesothelioma, but remains a challenge. Knowing the repartition and propagation of light around the light applicator could be the first step towards optimizing dosimetry. Here we propose a characterization method of the illumination profile of a specific light device.

METHODS

The light wand, made of a cylindrical diffuser located inside an endotracheal tube, was fixed in a tank filled with dilute 0.01% intralipid. Light dosimetry was performed around the tip of the wand using two complementary methods: direct measurements of light power with an isotropic probe and measurements of light distribution characterization.

RESULTS

Dosimetry with the isotropic probe showed an ellipse-shaped illumination. An optimized effective attenuation coefficient was deduced. Combined with the spatial representation, a theoretical illumination profile was established with iso-surfaces of fluence rate, defining a gradient light dose according to the distance from the diffuser.

CONCLUSION

A theoretical illumination profile of a light device was established and could be part of an intra-operative dosimetry system to improve light delivery during intrapleural PDT.

Management of malignant pleural mesothelioma-part 2: therapeutic approaches : Consensus of the Austrian Mesothelioma Interest Group (AMIG)

Treatment of malignant pleural mesothelioma (MPM) depends on performance status of the patient, tumor stage, and histological differentiation. Chemotherapy (CHT) can be administered as first- and second-line treatment in unresectable MPM or as neoadjuvant or adjuvant treatment before or after surgery. A combination of an antifolate and platinum-based CHT is the only approved standard of care. Several targeted and immunotherapies are in evaluation and further studies are warranted to determine the therapeutic value of these new treatment options. Radiotherapy (RT) can be considered either as adjuvant treatment after surgery or for palliation of pain-related tumor growth. Recent data support the use of RT in a neoadjuvant setting. Macroscopic complete resection by pleurectomy/decortication (P/D) or extrapleural pneumonectomy (EPP) is indicated in selected patients with good performance status. Surgery should only be applied as part of a multimodality treatment (MMT) in combination with chemo- and/or radiotherapy. In a large number of cases, palliative attempts are needed to improve quality of life and to achieve symptom control.

Surgery for malignant pleural mesothelioma

Malignant pleural mesothelioma is a locally aggressive asbestos-related cancer that has a worldwide distribution and an overall poor prognosis. The average median survival for patients receiving the current best nonsurgical therapy, cisplatin/pemetrexed chemotherapy, is between 7 and 13 months. In selected patients with early stage disease and favorable tumor characteristics, aggressive surgical management in combination with adjuvant or neoadjuvant therapy extends survival in up to 20% of patients. Despite the benefits of surgery for mesothelioma, many patients are not suitable for operative intervention due to advanced stage disease at presentation or the inability to tolerate aggressive surgical resection. The frontiers of mesothelioma research and treatment include an urgent search for biomarkers that can reliably detect early stage cancer in at-risk populations, clinical tests or indices that can reliably predict prognosis among surgical candidates and the development of efficacious drugs and targeted therapies that offer more durable local disease control.

A case of advanced malignant pleural mesothelioma treatment with chemotherapy and photodynamic therapy

Malignant pleural mesothelioma (MPM) is an aggressive, treatment-resistant, and generally fatal disease. A 68-year-old male who was diagnosed with MPM at another hospital came to our hospital with dyspnea. We advised him to take combination chemotherapy but he refused to take the treatment. That was because he had already received chemotherapy with supportive care at another hospital but his condition worsened. Thus, we recommended photodynamic therapy (PDT) to deal with the dyspnea and MPM. After PDT, the dyspnea improved and the patient then decided to take the combination chemotherapy. Our patient received chemotherapy using pemetrexed/cisplatin. Afterwards, he received a single PDT treatment and then later took chemotherapy using gemcitabine/cisplatin. The patient showed a survival time of 27 months, which is longer than median survival time in advanced MPM patients. Further research and clinical trials are needed to demonstrate any synergistic effect between the combination chemotherapy and PDT.

Management of malignant pleural mesothelioma-The European experience

Management of malignant pleural mesothelioma (MPM) remains a clinical challenge and the incidence of the disease will continue to increase worldwide. Several aspects of mesothelioma treatment are discussed controversially, in particular, regarding extent and best type of surgery, radiotherapy, and the role of neoadjuvant or adjuvant treatment. However, best survival data is reported from groups using multimodality treatment including macroscopic complete resection (MCR) achieved by either extrapleural pneumonectomy (EPP) or (extended) pleurectomy/decortication for patients qualifying from the tumor biology, stage, and patient's performance status and comorbidities. Several aspects have to be considered during surgery but morbidity and mortality have been reduced at experienced centres. The final analysis of extended selection algorithms is pending.

Intraoperative photodynamic therapy for malignant pleural mesothelioma: future or fad?

SUMMARY Malignant pleural mesothelioma is one of the most lethal cancers known to man, typically resulting in a life expectancy of approximately 1 year from the time of diagnosis. Surgery remains investigational in the treatment of this cancer, yet the treatments that appear to have the greatest potential to impact the course of the disease are those that are surgery-based. The goal of surgery, as part of a multimodal treatment plan, is to achieve a macroscopic complete resection of the cancer. There are two surgical approaches, extrapleural pneumonectomy and lung-sparing surgery. Extrapleural pneumonectomy is the most standardized approach and almost certainly achieves the most complete resection, leaving behind the least amount of microscopic disease. Essentially, no aspects of lung-sparing operations are standardized and all techniques are likely to leave behind more microscopic cancer than an extrapleural pneumonectomy, yet this approach has the principal advantage of avoiding pneumonectomy for what is rightfully considered a palliative procedure. There are some recent reports revealing more favorable survivals for patients undergoing lung-sparing rather than lung-sacrificing surgery, but there is no conclusive evidence favoring either approach due to general limitations in the surgical literature for malignant pleural mesothelioma. One multimodal approach that has produced notably long survival rates incorporated radical pleurectomy and adjuvant chemotherapy with intraoperative photodynamic therapy, a light-based cancer treatment. There is speculation that a photodynamic therapy-initiated immune response may have played a role in these results, but this has not been established. The contribution, if any, of photodynamic therapy to these results is an area of active investigation.

Radical pleurectomy and intraoperative photodynamic therapy for malignant pleural mesothelioma

BACKGROUND

Radical pleurectomy (RP) for mesothelioma is often considered either technically unfeasible or an operation limited to patients who would not tolerate a pneumonectomy. The purpose of this study was to review our experience using RP and intraoperative photodynamic therapy (PDT) for mesothelioma.

METHODS

Thirty-eight patients (42-81 years) underwent RP-PDT. Thirty five of 38 (92%) patients also received systemic therapy. Standard statistical techniques were used for analysis.

RESULTS

Thirty seven of 38 (97%) patients had stage III/IV cancer (according to the American Joint Committee on Cancer [AJCC manual 7th Edition, 2010]) and 7/38 (18%) patients had nonepithelial subtypes. Macroscopic complete resection was achieved in 37/38 (97%) patients. There was 1 postoperative mortality (stroke). At a median follow-up of 34.4 months, the median survival was 31.7 months for all 38 patients, 41.2 months for the 31/38 (82%) patients with epithelial subtypes, and 6.8 months for the 7/38 (18%) patients with nonepithelial subtypes. Median progression-free survival (PFS) was 9.6, 15.1, and 4.8 months, respectively. The median survival and PFS for the 20/31 (64%) patients with N2 epithelial disease were 31.7 and 15.1 months, respectively.

CONCLUSIONS

It was possible to achieve a macroscopic complete resection using lung-sparing surgery in 97% of these patients with stage III/IV disease. The survival we observed with this approach was unusually long for the patients with the epithelial subtype but, interestingly, the PFS was not. The reason for this prolonged survival despite recurrence is not clear but is potentially related to preservation of the lung or some PDT-induced effect, or both. We conclude that the results of this lung-sparing approach are safe, encouraging, and warrant further investigation.

Temoporfin (Foscan®, 5,10,15,20-tetra(m-hydroxyphenyl)chlorin)--a second-generation photosensitizer

This review traces the development and study of the second-generation photosensitizer 5,10,15,20-tetra(m-hydroxyphenyl)chlorin through to its acceptance and clinical use in modern photodynamic (cancer) therapy. The literature has been covered up to early 2011.

Photodynamic therapy and the evolution of a lung-sparing surgical treatment for mesothelioma

BACKGROUND

Photodynamic therapy (PDT) is a light-based cancer treatment that acts to a depth of several millimeters into tissue. This study reviewed the results of patients who underwent a macroscopic complete resection, by two different surgical techniques, and intraoperative PDT as a treatment for malignant pleural mesothelioma.

METHODS

From 2004 to 2008, 28 patients with malignant pleural mesothelioma underwent macroscopic complete resection, 14 by modified extrapleural pneumonectomy (MEPP) and 14 by radical pleurectomy (RP) and intraoperative PDT. The surgical technique evolved over this period such that 13 of the last 16 patients underwent lung-sparing procedures, even in the setting of large-bulk tumors.

RESULTS

Demographics in the MEPP and RP cohorts were similar in age, sex, stage, nodal status, histology, and adjuvant treatments. Stage III/IV disease was present in 12 of 14 patients (86%), with 50% or more with +N2 disease. The median overall survival for the MEPP group was 8.4 months, but has not yet been reached for the RP group at a median follow-up of 2.1 years.

CONCLUSIONS

In addition to the inherent advantages of sparing the lung, RP plus PDT yielded a superior overall survival than MEPP plus PDT in this series. The overall survival for the RP plus PDT group was, for unclear reasons, superior to results reported in many surgical series, especially for a cohort with such advanced disease. Given these results, we believe RP plus PDT is a reasonable option for appropriate patients pursuing a surgical treatment for malignant pleural mesothelioma and that this procedure can serve as the backbone of surgically based multimodal treatments.

Photodynamic therapy for malignant pleural mesothelioma: the future of treatment?

Malignant pleural mesothelioma is a deadly incurable cancer, with a median survival of approximately 9 months. The best available chemotherapy, arguably the standard of care, only yields a 40% response rate and an 11-week extension in median survival. Surgery, the modality most likely to be associated with prolonged remission, remains investigational and must always be combined with other modalities in an effort to treat the microscopic disease that will remain even after the most aggressive operations. One such modality, photodynamic therapy, is a light-based cancer treatment that has features making it particularly well suited as a component of a surgery-based multimodal treatment plan. Utilizing intraoperative photodynamic therapy has enabled development of a less drastic surgical procedure that is also yielding some encouraging survival results. A unique aspect of photodynamic therapy is its stimulation of a tumor-directed immune response, a feature that offers promise for designing future treatments.

Photodynamic therapy of cancer: an update

Photodynamic therapy (PDT) is a clinically approved, minimally invasive therapeutic procedure that can exert a selective cytotoxic activity toward malignant cells. The procedure involves administration of a photosensitizing agent followed by irradiation at a wavelength corresponding to an absorbance band of the sensitizer. In the presence of oxygen, a series of events lead to direct tumor cell death, damage to the microvasculature, and induction of a local inflammatory reaction. Clinical studies revealed that PDT can be curative, particularly in early stage tumors. It can prolong survival in patients with inoperable cancers and significantly improve quality of life. Minimal normal tissue toxicity, negligible systemic effects, greatly reduced long-term morbidity, lack of intrinsic or acquired resistance mechanisms, and excellent cosmetic as well as organ function-sparing effects of this treatment make it a valuable therapeutic option for combination treatments. With a number of recent technological improvements, PDT has the potential to become integrated into the mainstream of cancer treatment.

Photodynamic therapy as an adjunct to surgery or other treatments for squamous cell lung cancers

OBJECTIVES

Photodynamic therapy (PDT) was performed on 14 cases of tracheobronchial malignancies with variable tumor stages as an adjunct to surgery. We retrospectively reviewed these PDT cases to evaluate safety and oncologic outcome.

METHODS

From June 2004 to August 2010, PDT was performed in 14 cases for lung cancer. Medical records were reviewed, including demographic data, indication of the PDT, and oncologic outcomes, during the follow-up period.

RESULTS

There were 5 deaths, 1 loss of follow-up, and 5 patients that are still alive. There were 8 cases of complete response (CR), 4 cases of no response (NR), and 2 cases of partial response (PR). Among the recurrent tracheoendobronchial lesions in 5 patients, CR was accomplished in 4 patients and NR was observed in 1 patient. The mean survival of all patients was 23.9 months after PDT with a range of 6 - 66 months.

CONCLUSION

PDT demonstrates a safe and effective role as an adjunct to surgery in treating recurrent mucosal carcinoma in surgically high-risk patients. It is also effective for palliation of bronchial obstruction by cancer mass.

Pleural malignancies

Pleural malignancies, primary or metastatic, portend a grim prognosis. In addition to the serious oncologic implications of a pleural malignancy, these tumors can be highly symptomatic. A malignant pleural effusion can cause dyspnea, secondary to lung compression, or even tension physiology from a hydrothorax under pressure. The need to palliate these effusions is a seemingly straightforward clinical scenario, but with nuances that can result in disastrous complications for the patient if not attended to appropriately. Solid pleural malignancies can cause great pain from chest wall invasion or can cause a myriad of morbid symptoms because of the invasion of thoracic structures, such as the heart, lungs, or esophagus. This article reviews pleural malignancies, the purely palliative treatments, and the treatments that are performed with definitive (curative) intent.