Photodiagnosis and Photodynamic Therapy (2006) 3, 85—86
EDITORIAL
The new paradigm: Photodynamic therapy for the eradication of Barrett’s dysplasia and cancer—–Sufficiency versus efficiency
In this issue we have gathered together five expert papers describing the technique of photodynamic therapy for Barrett’s oesophagus and oesophageal cancer. There are a variety of approaches, but a lot which are consistent. The methodology of the randomized phase III trial for the eradication of high-grade dysplasia has not been rigorously adhered too by all groups [1]. Nor would one expect this, as the results are debated and new technologies are developed. Most are using a variety of ablation methods with endoscopic mucosal resection (EMR) for staging, and also for eradicating localised cancer. This technique is becoming more widespread, as definitive treatment and represents a challenge to the widespread adoption of photodynamic therapy. All agree that unless EMR can consistently eradicate all the metaplastic/dysplastic epithelium metachronous lesions are likely to reoccur. Therefore, combination therapy is essential with EMR for nodular focal lesions followed by PDT to eradicate all the Barrett’s epithelium. It is clear that all groups are using Photofrin in a standard dose; no one is consistently lowering the dose. The rationale is that the depth of necrosis must be sufficient, and there is great concern of inadequate treatment to an early or indeed occult cancer. This concern has meant that 5 aminolaevulinic acid is usually reserved for patients with flat benign appearing dysplasia detected serendipitously. There are still worries about burying a cancer under neosquamous epithelium. The treatment of mucosal disease is predicated on the certainty of it being mucosal disease. Therefore, all groups are very accurately staging the 1572-1000/$ — see front matter © 2006 Published by Elsevier B.V. doi:10.1016/j.pdpdt.2006.03.006
disease, with endoscopic ultrasound and indeed node sampling with fine needle aspiration. It is clear that the problem of metachronous cancer development is only addressed by treating the whole segment. Some groups will treat the whole area in one endoscopic session, whereas others will limit therapy to 5 cm only. Some are scrupulous with accurate positioning of a centering balloon whereas others are happy to use a bare fibre through the endoscope. Some will repeat therapy 24—48 h after initial irradiation to ensure all skipped areas are destroyed. If there are worrying areas of mucosal disease this may receive extra photoirradiation. What is the correct approach, and is accurate dosimetry essential? I have always believed so, but I am increasing swayed by the bare fibre approach. It works well, is simple and does allow accurate positioning. It would seem essential when using a bare fibre to repeat endoscopy to eradicate skip lesions. All groups are convinced of the need for complete ablation of the Barrett’s segment either in a staged or one session treatment. I agree with this and also with the premise that reflux and repeated degeneration must be prevented. Further therapy with thermal ablation or endoscopic mucosal resection is also necessary with pedantic and obsessive vigilance to this segment. The vital question remains is photodynamic therapy sufficient therapy for high-grade dysplasia and early cancer, or should we return to the ruthless efficiency paradigm of aggressive surgical excision. I believe that it is clear that if the disease is mucosal and localised it is controllable with photodynamic therapy. Subsequent chemoprevention is necessary
86 to stop repeated and further degeneration. If the disease has escaped to be regional then further therapy is clearly necessary. There remains the possibility of mucosal control with photodynamic therapy combined with chemoradiotherapy to ensure that undetected nodal and micrometastatic diseases are destroyed. An approach is adopted by breast surgeons to prevent the mutilation of mastectomy. Could a similar approach prevent the mortality and morbidity of oesphagectomy? It is time that this technique was more widely used and adopted by the cancer community. There is no doubt it is effective and sufficient therapy for many patients.
Editorial
Reference [1] Overholt BF, Lightdale CJ, Wang KK, et al. Photodynamic therapy with porfimer sodium for ablation of high-grade dysplasia in Barrett’s esophagus: international, partially blinded, randomized phase III trial. Gastrointest Endosc 2005;62(4):488—98.
Hugh Barr FRCS, FRCSE ∗ Cranfield Health, Cranfield University, Gloucestershire Hospitals Foundation Trust, Great Western Road, Gloucester GL1 3NN, UK ∗ Tel.:
+44 845 4226679; fax: +44 845 4226813. E-mail address: [email protected]
EDITORIAL
The new paradigm: Photodynamic therapy for the eradication of Barrett’s dysplasia and cancer—–Sufficiency versus efficiency
In this issue we have gathered together five expert papers describing the technique of photodynamic therapy for Barrett’s oesophagus and oesophageal cancer. There are a variety of approaches, but a lot which are consistent. The methodology of the randomized phase III trial for the eradication of high-grade dysplasia has not been rigorously adhered too by all groups [1]. Nor would one expect this, as the results are debated and new technologies are developed. Most are using a variety of ablation methods with endoscopic mucosal resection (EMR) for staging, and also for eradicating localised cancer. This technique is becoming more widespread, as definitive treatment and represents a challenge to the widespread adoption of photodynamic therapy. All agree that unless EMR can consistently eradicate all the metaplastic/dysplastic epithelium metachronous lesions are likely to reoccur. Therefore, combination therapy is essential with EMR for nodular focal lesions followed by PDT to eradicate all the Barrett’s epithelium. It is clear that all groups are using Photofrin in a standard dose; no one is consistently lowering the dose. The rationale is that the depth of necrosis must be sufficient, and there is great concern of inadequate treatment to an early or indeed occult cancer. This concern has meant that 5 aminolaevulinic acid is usually reserved for patients with flat benign appearing dysplasia detected serendipitously. There are still worries about burying a cancer under neosquamous epithelium. The treatment of mucosal disease is predicated on the certainty of it being mucosal disease. Therefore, all groups are very accurately staging the 1572-1000/$ — see front matter © 2006 Published by Elsevier B.V. doi:10.1016/j.pdpdt.2006.03.006
disease, with endoscopic ultrasound and indeed node sampling with fine needle aspiration. It is clear that the problem of metachronous cancer development is only addressed by treating the whole segment. Some groups will treat the whole area in one endoscopic session, whereas others will limit therapy to 5 cm only. Some are scrupulous with accurate positioning of a centering balloon whereas others are happy to use a bare fibre through the endoscope. Some will repeat therapy 24—48 h after initial irradiation to ensure all skipped areas are destroyed. If there are worrying areas of mucosal disease this may receive extra photoirradiation. What is the correct approach, and is accurate dosimetry essential? I have always believed so, but I am increasing swayed by the bare fibre approach. It works well, is simple and does allow accurate positioning. It would seem essential when using a bare fibre to repeat endoscopy to eradicate skip lesions. All groups are convinced of the need for complete ablation of the Barrett’s segment either in a staged or one session treatment. I agree with this and also with the premise that reflux and repeated degeneration must be prevented. Further therapy with thermal ablation or endoscopic mucosal resection is also necessary with pedantic and obsessive vigilance to this segment. The vital question remains is photodynamic therapy sufficient therapy for high-grade dysplasia and early cancer, or should we return to the ruthless efficiency paradigm of aggressive surgical excision. I believe that it is clear that if the disease is mucosal and localised it is controllable with photodynamic therapy. Subsequent chemoprevention is necessary
86 to stop repeated and further degeneration. If the disease has escaped to be regional then further therapy is clearly necessary. There remains the possibility of mucosal control with photodynamic therapy combined with chemoradiotherapy to ensure that undetected nodal and micrometastatic diseases are destroyed. An approach is adopted by breast surgeons to prevent the mutilation of mastectomy. Could a similar approach prevent the mortality and morbidity of oesphagectomy? It is time that this technique was more widely used and adopted by the cancer community. There is no doubt it is effective and sufficient therapy for many patients.
Editorial
Reference [1] Overholt BF, Lightdale CJ, Wang KK, et al. Photodynamic therapy with porfimer sodium for ablation of high-grade dysplasia in Barrett’s esophagus: international, partially blinded, randomized phase III trial. Gastrointest Endosc 2005;62(4):488—98.
Hugh Barr FRCS, FRCSE ∗ Cranfield Health, Cranfield University, Gloucestershire Hospitals Foundation Trust, Great Western Road, Gloucester GL1 3NN, UK ∗ Tel.:
+44 845 4226679; fax: +44 845 4226813. E-mail address: [email protected]
