Hexaminolevulinate- Induced Fluorescence Endoscopy in Patients with Rectal Adenoma and Cancer

Abstract

patients with colorectal polyps$2 cm resected in a general hospital from january 2001 to august 2003. Results: 118 large polyps were resected in 67 men and 39 women. 78 patients had an ER and 28 a SR. 43% of the ER were performed using endoscopic mucosal resection. An endoloop was necessary in 8% of cases, Argon plasma coagulation in 17% and clipping in 9%. 14% of SR were transanal, 14% laparoscopic and 71% open resections. A colectomy was necessary in 82% of SR. Polyp histology was similar in both groups. One perforation and one bleeding occurred in the ER group which required a surgical treatment and one of them died. No complication occurred in the SR group. 2 patients in the ER group had to be referred to surgery because a T1 carcinoma was diagnosed. A follow-up colonoscopy was performed in 26 patients of the ER group after a mean follow-up time of 6.5 months. Recurrence was detected in 9 patients : 6 had repeat ER and 3 were referred to surgery. Altogether 7 patients in the ER group had to be referred to surgery so that 33% of all patients had to be operated on. Whereas 14.6% of patients with pedunculated polyps had to be operated on, 45.2% of patients with sessile or flat polyps had to (p= 0.002). 44% of patients with polyps located in the right colon had to be operated on, whereas 24.1% of those with polyps in the left and transverse colon had to (p > 0.05). 24% of patients who had their colonoscopy performed by an expert endoscopist had to be operated on (20.7% of patients with benign polyps). 20 patients were referred to an expert endoscopist for a second attempt of ER and 75%were successful. 50% of patients in the SR group had not had an ER attempt by an expert endoscopist. Conclusions : one in three patients with a large colorectal polyp has to be operated on. The rate of referral to surgery may be decreased to one in five for benign polyps if an expert endoscopist gets involved. Referral to surgery is related to the size of polyps, their sessile or flat shape, their location in the right colon, their malignancy and to the lack of attempt of ER by an expert endoscopist. HexaminolevulinateInduced Fluorescence Endoscopy in Patients with Rectal Adenoma and Cancer Esther Endlicher, Cornelia Gelbmann, Ruth Knuechel, Alois Fuerst, Rolf-Marcus Szeimies, Stefan Goelder, Juergen Schoelmerich, Helmut Messmann Background and Aims: Fluorescence endoscopy is a promising new method for detection and therapy of premalignant and malignant lesions. The aim of the present pilot study was to investigate the feasibility of hexaminolevulinate based photodetection in patients with rectal adenoma and cancer, including safety, dosefinding and efficacy. Methods: 10 patients with known rectal adenoma and cancer were sensitised with 3.2 mM hexaminolevulinate (Photocure, Oslo, Norway). Fluorescence endoscopy was performed after an enema lasting for 30-60 minutes and a resting time of 0-30 minutes before endoscopy. Biopsies were taken from fluorescent and non-fluorescent areas and fluorescence microscopy studies were performed to investigate distribution of protoporphyrin IX (PPIX) fluorescence in different tissue layers. Adverse events were reported by open questioning in all patients while skin photosensitivity, serum transaminases, blood pressure, heart rate and gastric discomfort were recorded actively in 5 patients. Results: Hexaminolevulinate-induced fluorescence endoscopy led to selective fluorescence of all rectal adenoma containing intraepithelial neoplasia. In rectal cancer only a weak or even no fluorescence could be detected. No side effects related to hexaminolevulinatewere observed. In twopatients differentiation of adenoma and hyperplastic polyps was possible due to fluorescence. Conclusion: Hexaminolevulinate based fluorescence endoscopy using a 3.2 mM enema in patients with rectal cancer and adenoma was well tolerated and showed no significant skin sensitivity and other side effects. The optimal time of administration seems to be 30-45 minutes with a resting time of 30 minutes. Selective fluorescence of intraepithelial neoplasia containing adenoma indicates that hexaminolevulinatebased fluorescence endoscopy has the potential for the detection of premalignant lesions. Partially ulcerated surface, tumour necrosis and moderate differentiation are probably the reasons for lacking fluorescence in complete cancer after local sensitisation with hexaminolevulinate.