Photodynamic therapy as adjuvant therapy in surgically treated pleural malignancies

Our plain-English summary of Photodynamic therapy as adjuvant therapy in surgically treated pleural malignancies, by P. Baas, L. Murrer, F.A. Zoetmulder, et al (British Journal of Cancer, 1997).

The study

• Authors: P. Baas, L. Murrer, F.A. Zoetmulder, F.A. Stewart, H.B. Ris, N. van Zandwijk, J.L. Peterse, E.J. Rutgers
• Journal: British Journal of Cancer
• Published: 1997;76(6):819-26
• Cited by: 83 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Five patients with a pleural malignancy (four malignant mesotheliomas and one localized low grade carcinoid) were treated with maximal surgical resection of the tumour followed by intraoperative adjuvant photodynamic therapy (PDT). The additional photodynamic treatment was performed with light of 652 nm from a high power diode laser, and meta-tetrahydroxy phenylchlorin as the photosensitizer. The light delivery to the thoracic cavity was monitored by in situ isotropic light detectors. The position of the light delivery fibre was adjusted to achieve optimal light distribution, taking account of reflected and scattered light in this hollow cavity. There was no 30-day post-operative mortality and only one patient suffered from a major complication (diaphragmatic rupture and haematopericardium). The operation time was increased by a maximum of 1 h to illuminate the total hemithoracic surface with 10 J cm(-2) (incident and scattered light). The effect of the adjuvant PDT was monitored by examination of biopsies taken 24 h after surgery under thoracoscopic guidance. Significant damage, including necrosis, was observed in the marker lesions with remaining malignancy compared with normal tissue samples, which showed only an infiltration with PMN cells and oedema of the striated muscles cells. Of the five patients treated, four are alive with no signs of recurrent tumour with a follow-up of 9-11 months. One patient was diagnosed as having a tumour dissemination in the skin around the thoracoscopy scar and died of abdominal tumour spread. Light delivery to large surfaces for adjuvant PDT is feasible in a relatively short period of time (< 1 h). In situ dosimetry ensures optimal light distribution and allows total doses (incident plus scattered light) to be monitored at different positions within the cavity. This combination of light delivery and dosimetry is well suited for adjuvant treatment with PDT in malignant pleural tumours.

In plain English

This feasibility study tested adding photodynamic therapy, a light-activated drug treatment, to surgery for tumours of the pleura. Five patients treated in 1996 were included. Four had epithelioid malignant mesothelioma, and one turned out to have a low grade carcinoid tumour. Patients received the drug mTHPC four days before surgery. After removing as much tumour as possible, surgeons lit the chest cavity with laser light while probes measured the dose, aiming for an average of 10 J cm-2. The light treatment took at most 1 hour. No patient died within 30 days. One patient had a ruptured diaphragm needing another operation and later had bloody fluid drained from around the heart. Biopsies taken a day later showed more damage, including dead tumour cells, in tumour than in normal tissue. One patient died of tumour spread at 7 months, which the authors thought may have started from a biopsy port. The other four had no sign of recurrence at 9 to 11 months. The authors concluded the approach was feasible but said larger, longer studies were needed. The article does not discuss asbestos.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Feasibility study (small case series) of surgery followed by intraoperative photodynamic therapy with in situ light dosimetry
• Who was studied: Five patients treated at the Netherlands Cancer Institute, Amsterdam, between January and June 1996. Four had diffuse epithelioid malignant mesothelioma and one had a localized carcinoid tumour first diagnosed as mesothelioma. They were four men and one woman, aged 37 to 59. A sixth patient was found irresectable at operation and did not receive PDT.
• Exposure: The article reports no asbestos or other occupational exposure. The intervention studied was mTHPC, 0.1 mg per kg given 4 days before surgery, followed by 652 nm laser light to the chest cavity with a target average dose of 10 J cm-2.
• Main results:
  • The photodynamic treatment took at most 1 hour per patient, including placement of the probes and the bag.
  • Average light doses for the cavity were 10.1, 10.0 (10.6 in the text), 10.3, 8.9 and 9.4 J cm-2 in patients 1 to 5. In patient 1 the diaphragmatic sinus at first received less than 1 J cm-2 and was given extra illumination.
  • No patient died within 30 days. Hospital stay was under 3 weeks for patients 1, 2, 3 and 5; patient 4 stayed 41 days.
  • Patient 4 had a diaphragmatic rupture requiring rethoracotomy. That patient later developed a pericardial effusion, and 500 cm3 of haemorrhagic fluid was removed.
  • In biopsies taken 24 hours after treatment, inflammatory cell infiltration and oedema were more marked in tumour tissue than in chest wall samples where tumour had been completely resected. Necrotic residual mesothelioma was seen in patient 1's target lesion.
  • Patient 3 developed tumour spread from the thoracoscopic scar and died of local and abdominal tumour spread 7 months after treatment.
  • The other four patients were alive without evidence of tumour recurrence at 9 to 11 months of follow-up.
• The authors' conclusion: The authors concluded that combining PDT with surgical resection for pleural tumours is feasible, and that in situ light dosimetry improves the reproducibility and control of the treatment.
• Limitations the authors state:
  • Larger numbers of patients and longer follow-up are needed to tell whether the treatment benefits local control and survival.
  • The indwelling thoracoport used for biopsies may have spread tumour cells in the patient who died, so the authors abandoned this practice.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Adjuvant Therapy, Malignant Mesothelioma, Surgical Resection, Necrosis, Thoracoscopy.

Related studies

• Experimental assessment of photodynamic therapy with chlorins for malignant mesothelioma — H.B. Ris, A. Giger, et al. (1997)
• Fluence plays a critical role on the subsequent distribution of chemotherapy and tumor growth delay in murine mesothelioma xenografts pre-treated by photodynamic therapy — Y. Wang, X. Wang, et al. (2015)
• A preclinical model to investigate the role of surgically-induced inflammation in tumor responses to intraoperative photodynamic therapy — R.W. Davis, E. Papasavvas, et al. (2018)
• Real-time light dosimetry for intra-cavity photodynamic therapy: Application for pleural mesothelioma treatment — N. Betrouni, C. Munck, et al. (2017)
• Photodynamic therapy for lung cancer and malignant pleural mesothelioma — C.B. Simone, K.A. Cengel (2014)
• A Novel Prospective Study Assessing the Combination of Photodynamic Therapy and Proton Radiation Therapy: Safety and Outcomes When Treating Malignant Pleural Mesothelioma — S.R. Rice, Y.R. Li, et al. (2019)

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