Wedge-shaped applicator for additional light delivery and dosimetry in the diaphragmal sinus during photodynamic therapy for malignant pleural mesothelioma

• Published in: Physics in medicine & biology Vol. 46; no. 7; pp. 1873 - 1883
• Main Authors: Veen, R L P van, Schouwink, J H, Star, W M, Sterenborg, H J C M, Sijp, J R M van der, Stewart, F A, Baas, P
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.07.2001; Institute of Physics
• Subjects: Aged; Biological and medical sciences; Diseases of the respiratory system; Humans; Light; Male; Medical sciences; Mesothelioma - therapy; Phantoms, Imaging; Photochemotherapy - methods; Pleural Neoplasms - therapy; Pneumology; Radiometry - instrumentation; Radiometry - methods; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Time Factors; Tumors of the respiratory system and mediastinum; Performance evaluation; Human; Geometrical shape; Photodynamic therapy; Respiratory disease; In situ; Instrumentation therapy; Malignant tumor; Experimental study; Design; Malignant mesothelioma; Applicator; Decision aid; Pleural disease; Dosimetry; Treatment planning; Pleura; Test object
• ISSN: 0031-9155; 1361-6560
• DOI: 10.1088/0031-9155/46/7/310

In situ light dosimetry during photodynamic therapy (PDT) of malignant pleural mesothelioma (MPM) after tumour resection facilitates the delivery of a controlled light distribution to the inner thoracic surface. Illumination of the diaphragm-induced sinus, however, remains difficult. Our aim was to develop a wedge-shaped light applicator with incorporated light dosimetry to deliver an additional fluence limited to the sinus. The wedge-shaped applicator contains a cylindrical diffuser for light delivery and two isotropic detectors for simultaneous light dosimetry. These detectors were placed at strategic positions where the fluence rate is maximal or minimal (middle and edge). Prior to its clinical use, the performance of the sinus light applicator was tested in several optical tissue phantoms with different optical properties. The fluence rate distribution over the surface of the applicator showed little change when the wedge was submerged in four different optical phantoms. During clinical PDT of MPM the applicator had to be re-located manually four times in order to give an additional fluence of approximately 2 J cm(-2) to the entire sinus. The light applicator enables dosimetry-controlled light delivery for additional illumination of the sinus region that is often under-illuminated during thoracic integral illumination of MPM.