INTERSTITIAL PDT FOR PRIMARY AND METASTATIC TUMOUR

Photo courtesy of House of Laser

PDT is one of the interesting modalities in cancer treatment.The availability of several photosensitizers and lasers are opening new pathways in photodynamic medicine, leading to a new era in the future of medicine.
(It should be mentioned that PDT will not be an umbrella only in oncology but will cover some areas including infectious and other degenerative processes or diseases as well.)
A technique of interstitial PDT has been offered in conjunction with other modalities in cancer treatment,as shown in this picture.
Selective cancer cells death by apoptosis and necrosis has been proposed to a formation of lysate following cytotoxic process of cancer cells.
Secondly vascular shutdown is another way to the killing of cancer cells.
Positive immune response is another way leading to improvement of patient condition.(see: Immunologic aspect of PDT/Laser therapy,a review by Santoso Cornain,MD,D.Sc, a link in this blog)

LIMFOMA MALIGNUM TONSIL

Tonsil membesar satu sisi mungkin bukan pembesaran tonsil biasa akibat infeksi.Kemungkinan tumor harus difikirkan yaitu limfoma malignum yang melibatkan tonsil dan cincin Waldeyer.
Foto ini menunjukkan limfoma malignum pada tonsil palatina kanan.
Pada endoskopi ternyata dicurigai melibatkan jaringan limfoid nasofaring.
Gangguan menelan diatasi dengan pengangkatan tonsil yang mengandung tumor disusul dengan kemoterapi dan radiasi.

PDT:AFTER 4x24 HOURS

This picture showed tumor condition 4 days after first illumination with laser.
The tumor was seen with prominent parts of necrotic (lower picture)and liquified mass(upper picture) area as result of PDT.
Please view pictures of previous posting.
Posting of PDT cases were also presented in Indonesian language in:
http://cahayamasadepan.blogspot.com

PDT: AFTER 2X24 HOURS

Interstitial technique of PDT is used to debulk huge tumours.
The debulking process started hours after illumination by direct cytotoxic effect of PDT into tumour cells and by vascular shutdown
resulting in tumor apoptosis and necrosis.
In order to treat tumours thicker than 1 cm(limit of light penetration depth into the human tissue),the interstitial illumination technique was invented.
By this technique laser fibres with a light diffuser at the tip are implanted into the tumour tissue.
Laser fibres are feed-through needles,which can be placed under image guidance in the tumour(CT,MRI or US).
In large tumours,several fibres can be placed close to each other(12 cm apart) in order to illuminate the entire tumour volume.
Interstitial light delivery allows PDT to be used in the treatment of large,buried tumours and is particularly suitable for those whose surgery would involve extensive resection or for those who are unsuitable for surgery.
Due to the difficult and non precise light dosimetry in the tumout,interstitial PDT is mainly used with palliativeintention,as stated by Xu et al.
The pictures shown are PDT in large tumour of the neck,before (upper picture)and 2x24 hours (lower picture)after laser interstitial illumination.

PDT:A NOVELL APPROACH TO CANCER TREATMENT

The content of this posting is derived from the review by Kecheng Xu,Guo Zhiqian,Lizhi Niu,from Fuda Cancer Hospital, Guangzhou.

PDT is a promising new approach for the treatment of cancer.

The principle of PDT is based on photochemical reaction,which is initiated by light activation of a photosensitizing drug causing tumour cell death.

Light is mainly applied by superficial illumination of the tumour and the surrounding tissue causing drug activation followed by tumour cell death.

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 practiceable option for solid lesions,including those in parenchymal organs such as the liver.

New techniques use glass fibres,which are stabbed into the tumour,leading the light directly into the tumour tissue.

The intra-operative application of PDT to treat and "mop-up" the tumour bed of any remaining tumour cells has been reported.

PDT damage heals mainly by regeneration rather than by scarring.
Due to the organ preserving principle of PDT,important structures are maintained with good functional and cosmetic outcome.

The principle of PDT and different indications for PDT were reviewed.

(Pictures show PDT procedure done in Gading Pluit Hospital,Jakarta,Indonesia. Photo courtesy of this blog author)