Consideraciones geomecánicas

The results of laser and radiotherapy for rectosigmoid cancer are more encouraging than those for oesophageal cancer with the reservation that only a small number of patients have been treated in a pilot study. The laser treatment intervals for effective palliation for this group appear to have increased from 1 month to about 3 months with the addition of external beam radiotherapy. In the context of an impressive median survival of 15 months these results are very promising. Most of the studies on laser as palliation for rectal cancer discussed in chapter 2 report median survival times of around 6 months and so this may represent a survival benefit. It is important to remember that the patients selected as suitable for this trial were only

around 1/3 of allcommers and a larger randomised study needs to be performed to confirm these results.

10.3 C ollaboration with radiotherapists

We have found that there is an important advantage in locating a laser in a unit associated with interested radiotherapy team. It allows a radiotherapy opinion to be obtained and treatment to be commenced promptly in appropriate patients. The expertise in counselling and support available fiom nurses trained in oncology may also be a benefit. Many patients with squamous cell oesophageal cancer are referred directly for radiotherapy. During the course of collaborative studies we have received more referrals of such patients from radiotherapists as they have become more aware how effective endoscopic techniques can be in restoring swallowing quickly. The availability of endoscopic expertise may thus prevent patients languishing on oncology wards unable to swallow and requiring NG feeding.

The cooperation between specialties works both ways. We have been treating groups of patients such as those with squamous cell oesophageal cancer and many of those with rectal cancers who would previously have been treated by radiotherapists. It is therefore not surprising that they also have expertise which we lack. A few patients with squamous cell oesophageal cancers referred to us for palliation have been deemed suitable for radical radiotherapy treatment. One of these patients is alive and disease free after more than 3 years! Another group often referred for laser are those with low rectal cancers growing into the perineum. Being superficial, the response to radiotherapy is good and usually superior to that possible with laser.

10.3 The laser and tube-a compJImentarv duo

Over the last few years there has been an ongoing debate on the relative merits of

tube and laser. We would argue that they are compUfnentary; use of the appropriate ^

modality at a given point in time for each individual will maximise benefît with the least number of interventions possible.

An earlier paper from our unit (Loizou 1991) described a prospective comparison of laser therapy and intubation in the palliation of malignant dysphagia. The results were discussed in detail in chapter 2. Overall the group receiving laser swallowed better than those intubated but required more procedures (mean 4.6 v 1.4). Solids could be managed for more than half the survival time in 1 in 3 of those treated with laser but only 1 in 10 of those intubated. In addition the proportion of patients managing fluids only is double in patients intubated compared with patients receiving laser therapy (19% v 8%). In simple terms around 1/3 of these patients swallowed better with laser than a tube but more than 70% of those intubated will manage at least semi-solids.

The dysphagia data as reported by Loizou gives a slightly pessimistic view as many laser treated patients managing a semi solid diet most of the time are able to eat some solids for a period after each treatment and are thus doing better than with a tube! Many such patients are reluctant to be intubated but are content to have repeated laser treatments. In the randomised study looking at laser and radiotherapy dysphagia results are rather better. Around two thirds of the patients entered swallowed some solids for most of their remaining lives. This may be partly due to patient selection as patients had to be considered fit for external beam radiotherapy. It is possible however that our technique is now more 'aggressive' than in the previous study. We are probably 'vaporising' more tumour than previously and this may account for some of the discrepancy. Reviewing the recent literature there is some evidence to suggest that well over half of those treated with the Nd YAG laser do indeed manage a solid diet for much of their survival (Naveau 1990, Mason 1991).

Most studies discussed in chapter 2 report a far higher complication rate with intubation than with laser. One can therefore argue that many of those managing semi-solids on average with laser should not be intubated and our policy is to carefully assess each patient individually.

The management of patients who are unable to manage semi-solids most of the time with laser or whose survival is likely to be short is less controversial. We routinely advise such patients to be intubated.

Expanding further on the same theme there are situations where tubes can benefit patients with laser and radiotherapy induced complications. Chapter 8 describes the use of cuffed (Wilson Cooke) tubes in 3 groups of patients with complications some of which were laser induced. These tubes are designed for patients with malignant oesophago-respiratory fistulae. We have treated seven such cases 2 of whom had laser induced fistulae. Six closed after intubation and the other tube displaced and could not be repositioned. Patients with instrumental perforation and those with life threatening arterial bleeding from cardia cancers in whom laser was ineffective also benefited from these tubes.

Chapter 9 documents the successful use of Nd YAG laser in 14 patients with overgrowth of conventional tubes; this is another example of optimising patient benefit by using the appropriate treatment modality at the right time.

In summary we argue that laser and tube are com p^entary. The availability of both treatments offers any individual a better initial choice than either alone and should he or she develop complications later on the option of resorting to the "other" modality may be advantageous.

The tube studies performed confirm that tubes and laser are complimentary treatments in patients with oesophageal cancer. It is therefore important that centres performing endoscopic treatment should be equiped for a variety of treatments. X- ray screening is necessary for tube insertion. Such facilities are more likely to be available in specialist centres.