Transoral laser microsurgery (TLM) is a relatively new treatment in the United States and is a viable option for several types of head and neck cancer, allowing physicians to target tumors without needing to surgically disassemble the patient, according to the experts interviewed for this article.
Gaining Acceptance in US
Surgeons in the United States began using TLM to treat tumors outside the larynx more than 10 years ago and have been increasingly using the technology to resect larger, more advanced stage head and neck tumors, said Michael Hinni, MD, Associate Professor at Mayo Medical School and a consultant in the Department of Otorhinolaryngology at Mayo Clinic in Scottsdale, AZ.
Most tertiary centers have a head and neck surgeon who is familiar with the technology, he said. But there still aren’t very many people with any significant experience. We’re working to change that.
Transoral laser microsurgery has taken a while to gain acceptance in the United States because of concerns about what happens when you split a tumor into pieces as it is being removed, said Salvatore Caruana, MD, Assistant Professor of Otolaryngology-Head and Neck Surgery at Columbia University Medical Center in New York. To split a tumor and segmentally remove it meets with intuitive opposition, he explained.
Despite any trepidation, the procedure is becoming more popular largely because of its low morbidity and excellent cure rates compared to those of chemoradiation, which has been a mainstay for head and neck cancer for the past 10 to 15 years, said John Salassa, MD, Associate Professor at Mayo Medical School and a physician in the Department of Otolaryngology-Head and Neck Surgery at Mayo Clinic in Jacksonville, FL.
The procedure is generally indicated for patients with early-stage or medium-stage head and neck tumors, including squamous cell cancers of the oral cavity, oropharynx, hypopharnyx, and larynx, said Dr. Caruana.
Physicians at Mayo Clinic will consider TLM for most head and neck cancers. We can treat just about any T1 or T2, most T3, and some T4 tumors, explained Dr. Salassa.
The clinic has a database of approximately 800 patients who have undergone TLM since 1996.
Evaluation of this database has led researchers there to conclude that TLM is safe and effective in patients with previously untreated squamous cell cancer of the supraglottic larynx (Otolaryngol Head Neck Surg 2007;136:900-6) and in select patients with glottic larynx carcinoma (Otolaryngol Head Neck Surg 2007;137:482-6).
Selected patients with early and advanced previously untreated squamous cell tongue base cancer are also candidates for the procedure (Laryngoscope 2006;116:2150-5) as are those with persistent, recurrent, or secondary primary disease (Laryngoscope 2006;116:2156-61).
In patients with advanced laryngeal cancer, TLM with or without radiotherapy is also a viable option for that can help preserve the larynx (Arch Otolaryngol Head Neck Surg 2007;133:1198-1204).
Additionally, the procedure may have a role as a salvage therapy for select patients with previously treated laryngeal or pharyngeal squamous cell cancer, according to Mayo Clinic data presented at the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) 2007 meeting last fall.
In a prospective case series, 109 patients received salvage TLM for recurrent primary tumors, while 55 underwent the treatment for new primary cancers in a previously treated site. The two-year local control rate was 75%, whereas locoregional control was 72%. Overall survival and two-year disease-free survival rates were 70%.
This was a select group of patients, and their tumors and surrounding tissue received a close frozen section analysis, allowing for comprehensive treatment, said Dr. Salassa.
Transoral laser microsurgery is not an option when the primary tumor invades the neck and involves carotid arteries, said Dr. Hinni, adding that an open operation is generally required.
However, in some cases where tongue base and tonsil cancers have spread into the neck and encased nearby blood vessels, the surgeon may be able to remove intraoral tumors with a laser and then resect the rest through the neck, said Dr. Salassa.
Another contraindication for TLM is when the primary tumor and the cancerous lymph nodes are quite large and emerge together, said Dr. Hinni.
Additionally, if the patient has laryngeal cancer and so much of the organ has to be removed that it prevents the larynx from functioning, TLM should not be used, said Dr. Salassa.
If open reconstruction is necessary for functional or cosmetic reasons, there is no added benefit of using TLM, said Dr. Hinni. For example, mouth cancer that has grown into the jawbone will require replacing the mandible with a fibula. Under these circumstances, the surgeon has to open up the patient, he explained.
Physicians also avoid TLM if the patient’s neck is too stiff and cannot be pushed back or the mouth or jaw is too small, preventing instrument access to the tumor, said Dr. Caruana.
Moreover, if patients cannot tolerate anesthesia for medical reasons, such as significant lung or heart disease, they may not be good candidates for TLM, added Dr. Caruana.
Transoral laser microsurgery offers many advantages over more traditional therapies, such as open surgery and chemoradiation.
For example, with TLM physicians can map tumors and remove them without disturbing structures, nerves, and tissues because the procedure does not require making incisions through the neck as with open surgery, said Dr. Caruana. Instead, surgeons can take the tumor out through the mouth. In addition, TLM helps surgeons avoid tracheostomy, which is often needed to create a safe airway because of postoperative swelling associated when more traditional open surgical approaches, he explained.
TLM also lets physicians avoid disassembling the patient while clearing tumors, and results in fewer salivary leaks and fistulas as compared with open surgery, said Dr. Hinni.
Moreover, patients undergoing TLM are able to swallow earlier than those who undergo open surgery and don’t have to wait for suture lines to mend, Dr. Hinni added.
Generally, hospital stays after TLM are two to three days, compared with a week to 10 days for open surgery, said Dr. Salassa.
TLM also helps physicians make decisions about postoperative therapy because the procedure requires meticulous frozen section analysis and careful evaluation of the entire tumor and neck disease, said Dr. Salassa. We have true pathologic staging and can more effectively prescribe adjuvant therapy, he said.
Because TLM can render a complete response in patients, if adjuvant therapy is indicated it may be possible to use lower doses of radiation or chemoradiation, said Dr. Salassa.
For treating first primary tumors, TLM is often a better option than radiation, said Dr. Caruana. If TLM is used for first primary cancers it can be used again for second primary tumors, whereas if radiation is used for first primary tumors, it cannot be used again, he explained. If you use TLM for the initial tumor, it leaves the option of further laser treatment as well as radiation treatment if the patient develops a second cancer or a tumor recurrence, he said.
One drawback of TLM is that many patients will experience temporary minor aspiration, said Dr. Salassa. However, most people can tolerate this pretty well until healing takes place and they can swallow again, he said.
Another risk associated with the procedure is bleeding, which is rare but serious, said Dr. Salassa. It can be a real issue because with TLM we don’t close these wounds but leave them to heal by secondary intention, he said. If the patient does bleed and he or she is already aspirating, the situation can be life-threatening, he explained.
In an abstract presented at the AAO-HNS 2007 meeting, Mayo Clinic researchers found that 10 of 701 patients in their database treated with TLM for cancer of the oral cavity, pharynx, and larynx experienced bleeding. Two patients suffered minor bleeds that required observation only. Five patients had major bleeds requiring exploration and treatment under general anesthesia. Three patients had catastrophic bleeds that were life-threatening, two of which resulted in death.
To prevent bleeding, an understanding of anatomy is necessary, said Dr. Salassa. Placing large clips on blood vessels 2 mm or larger, cauterizing smaller vessels, and being careful when dividing and removing tumors that are vascularly tethered to surrounding tissues is also important, he said.
With large tumors, tying off branches of the external carotid system can also help to prevent bleeding, said Dr. Salassa.
As with any surgery, infections are another complication, noted Dr. Caruana. Additionally, fistula formation may occur but is extremely rare and less common than with conventional surgery. The scope in the mouth can also injure teeth and lips, he added.
What Patients Should Know
Before undergoing treatment, every patient should be evaluated by a multidisciplinary head and neck cancer committee and apprised of their options, including radiation and chemotherapy strategies and up-front open surgery or TLM with the possibility of adjuvant therapy, said Dr. Hinni.
Regarding TLM, patients should understand that the procedure treats the primary site of the tumor and that the local control rates are excellent, said Dr. Salassa.
Treatment of head and neck tumors is a very complex topic to discuss with patients, said Dr. Caruana. However, they should know that each case is unique and that if TLM is chosen it is customizable to the individual patient, he concluded.
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