LASERS

Laser treatment can bring immediate symptom relief without the side effects of chemotherapy and radiotherapy. Lasers have been used since 1982 for endoscopic palliation of inoperable tumors of the bronchus and esophagus.

The Nd YAG laser can re-canalize or de-bulk advanced tumors of the bronchus, esophagus or rectum, and can be transmitted by flexible fibers via a fiberoptic endoscope. It vaporizes tumor cells and coagulates blood vessels up to 1mm in diameter. It can relieve local symptoms - dysphagia, dyspnea, hemoptysis, rectal bleeding and obstruction. It usually needs to be repeated. (see Bleeding)

Only exophytic tumors are suitable for laser resection.

Laser therapy (photo-resection) is indicated for dyspnea or recurrent hemoptysis in patients with bronchial cancers which have a significant intraluminal component. It can reduce the size of the obstructing tumor and improve breathing in 75% of patients, and controls bleeding in 60%. It can be used under local anesthetic, but smoke is generated, which causes coughing. Most physicians prefer to use a rigid bronchoscope under general anesthetic. It is useful for the urgent treatment of severe stridor due to tracheal tumors. Laser has the advantages of immediate response, no systemic toxicity, and the ability to repeat treatment when required.

Dysphagia due to esophageal cancers can be relieved by laser therapy. Preliminary dilation of the tumor is necessary when using a no-touch laser. New sapphire probes now allow direct contact and thus can treat tumors when obstruction is complete and even a guide wire cannot be passed. The technique is effective and over 90% of patients have improved swallowing. (The perforation rate is about 4%.) Once the patency of the lumen is restored, treatment can be repeated every 4 to 6 weeks. Laser therapy can be used to treat overgrowth of a prosthetic tube.

Further study is needed to compare laser treatment alone, and in combination with intracavity radiation and prosthetic intubation.

Laser can control obstruction, bleeding and discharge from rectal cancers. Pain relief can be provided by tumor de-bulking only, but not if the lesion has invaded the sacrum or sacral plexus. Incontinence due to the spread of the tumor into the anal margin cannot be relieved. Laser provides palliation that is as good as (or better than) radiotherapy, electro-coagulation or cryotherapy. A rectal washout is required before treatment, which is usually under general anesthetic, because the heating effect can be painful. The perforation rate is low. The treatment can be repeated every 4 to 6 weeks. In occasional patients, the benefits last several months.

With superficial bladder tumors there is a small body of evidence that laser therapy produces a lower recurrence rate than resection or electro-coagulation. Laser therapy for deep penetrating bladder tumors may have a place in patients unfit for radical treatment, to de-bulk tumors or control bleeding.

The author and publisher have taken precautions to ensure that the information in this book is error-free. However, readers must be guided by their own personal and professional standards of good practice in evaluating and applying recommendations made herein. The contents of this book represent the views and experience of the author, and not necessarily those of the publisher.