Interstitial photodynamic laser therapy in interventional oncology

Abstract

Photodynamic therapy (PDT) is a well-investigated locoregional cancer treatment in which a systemically administered photosensitizer is activated locally by illuminating the diseased tissue with light of a suitable wavelength. PDT offers various treatment strategies in oncology, especially palliative ones. This article focuses on the development and evaluation of interstitial PDT for the treatment of solid tumors, particularly liver tumors. The PDT is mostly used for superficial and endoluminal lesions like skin or bladder malignancies and also more frequently applied for the treatment of lung, esophageal, and head and neck cancer. With the help of specially designed application systems, PDT is now becoming a practicable option for solid lesions, including those in parenchymal organs such as the liver. After intravenous treatment with the photosensitizer followed by interstitial light activation, contrast-enhanced computed tomography shows the development of therapy-induced necrosis around the light-guiding device. With the use of multiple devices, ablation of liver tumors seems to be possible, and no severe side effects or toxicities related to the treatment are reported. PDT can become a clinically relevant adjunct in the locoregional therapy strategies.

In vivo measurement of parameters of dosimetric importance during interstitial photodynamic therapy of thick skin tumors

“…Interstitial photodynamic therapy has been applied in the treatment of several conditions, for example, malignancies in the prostate, 29 liver, 30 and pancreas. 9 Various photosensitizers have been used in those studies, and relatively large treatment volumes have been obtained.…”

Clinical system for interstitial photodynamic therapy with combined on-line dosimetry measurements

“…Thus, in an effort to extend the possible indications for PDT, we present a system for interstitial PDT (IPDT), where thick or embedded tumors are treated using optical fibers inserted into the tumor. IPDT has been pursued for many indications, for example, prostate, 10 liver, 11 and pancreatic cancer 12 ; and in this clinical or preclinical work it has been stated that the main drawbacks of the method as applied today are the limited light penetration and the lack of a more precise light dosimetry. A special aspect of the work performed in our group is to use the optical fibers not only to deliver the therapeutic light but also to perform optical measurements to assess parameters of therapeutic interest and to monitor the treatment progression.…”

Adrenal metastases: CT-guided and MR-thermometry-controlled laser-induced interstitial thermotherapy

“…MR monitoring allows rapid acquisition of areas of signal loss compatible with temperature changes and, thus, real-time documentation of laser ablation effects [14,36,37]. The applicator position, laser power and cooling rate can be readjusted according to MR imaging during treatment.…”