CO2 laser surgery in otorhinolaryngology-site and complications: a 10-year experience at Ramathibodi Hospital.

OBJECTIVE: To present data on ten years' experience in CO2 laser surgery and associated complications among otorhinolayngologic patients. MATERIAL AND METHOD: The study involved examining records of otorhinolaryngologic patients who underwent CO2 laser operations during a 10-year period (July 1, 1986-June 30, 1996). The sample consisted of 733 patients: 370 male and 363 female patients. CO2 laser surgery in otorhinolaryngology was first used in Ramathibodi Hospital on July 10, 1986. RESULTS: These patients were aged 2 months to 93 years with the mean age of 24.3 years (median = 16 years). Among 1,725 operations, 1,570 operations (91%) were performed under general anesthesia and 155 operations (9%) were performed under local anesthesia. In our series, the most frequent sites for laser surgery were as follows: larynx (77.22%), oral cavity and oropharynx (12.64%), skin (5.04%) and nose and paranasal sinuses (3.31%). Intraoperative complications occurred in 18 out of 1,725 (intra-operative complication rate of 1%). Laser-related complications were found in 13 out of 1,725 operations (0.75%) and non laser-related complications were found in 5 out of 1,725 operations (0.25%). There was no mortality. CONCLUSION: CO2 laser is a useful modality of treatment in otorhinolaryngologic surgery especially in the larynx. Our experience demonstrates the relative low incidence of complications (1%) and no mortality in otorhinolaryngology head and neck surgery.

Performance characteristics of fluorescence endoscope in detection of head and neck cancers.

Laser-induced fluorescence endoscopy (LIFE) is a noninvasive method for detecting early cancers in hollow organs. A laser-induced fluorescence endoscope that was designed for lung imaging was investigated for its effectiveness in comparison to white light endoscopy (WLE) in localizing head and neck cancers. A total of 196 images from 98 sites in 56 patients were graded into 5 levels from normal to definitely abnormal. A cutoff level to differentiate normal from abnormal images was chosen from a receiver operating characteristic curve. On this basis, LIFE (sensitivity, 92.86%; specificity, 78.57%) was observed to be more effective and reliable than WLE (sensitivity, 67.86%; specificity, 70%) in locating neoplastic foci and precancerous lesions. Nevertheless, WLE was helpful in presenting anatomic details. The reliability of LIFE varied from site to site. It excelled in examination of the oropharynx (sensitivity, 100%; specificity, 96.20%), but was less effective for lesions of the nasopharynx (sensitivity, 66.70%; specificity, 75.00%). In standardizing the test, interobserver variation was assessed, and good agreement in image interpretation was confirmed by statistical analysis. In conclusion, LIFE was found to be an effective and reliable tool for detecting head and neck cancers.

Minimally invasive KTP laser treatment of perennial allergic rhinitis: a preliminary report.

OBJECTIVE: To test the efficacy of KTP laser in controlling perennial allergic rhinitis symptoms in a minimally invasive fashion. MATERIALS AND METHODS: Fifty-eight cases of refractory perennial allergic rhinitis were included in this self-controlled study. The anterior one-fourth of the inferior turbinate of one side of the nose was lased by KTP laser at 12 watts, continuous mode, the total energy per side ranging from 121 to 440 joules (mean = 252). The other side of the nose was left untreated to serve as a control. The longest follow-up time was 20 months. RESULTS: Five patients were lost to follow-up; 53 patients were available for evaluation. For the overall result, 81% of patients reported good to excellent subjective improvement, 16.6% had fair, and 1.8% had poor subjective improvement of symptoms. The mean (+/- SD) degree of improvement in the treated and untreated sides was 77.1 +/- 17.8% and 38.4 +/- 29.4%, respectively; this was statistically significant (p < .001). This improvement remained at 20 months follow-up, and there were no complications. CONCLUSION: A single minimally invasive KTP laser treatment of perennial allergic rhinitis according to the parameters employed in this study is an effective approach resulting in moderately long-term improvement.

Cryopreserved, irradiated tracheal homograft transplantation for laryngotracheal reconstruction in human beings.

Subglottic tracheal stenosis is a common clinical entity. Management in severe cases is often problematic. Various techniques for tracheal replacement have been used with varying degrees of success. In this study we used cryopreserved, irradiated tracheal homografts, the use of which in human beings has not been reported previously. In a sterile setup, the tracheas were harvested from donor cadavers within 24 hours of death. The grafts were initially kept at 57 degrees C for 20 minutes; they were then placed in a -70 degrees C chamber for another 2 to 3 days or more and were irradiated to 25 kGy (2.5 million rad). Finally, the grafts were stored at -70 degrees C until usage. Seven patients underwent the surgery, but only 4 are presented here. In the remaining 3 patients, the follow-up time was too short to be evaluated. Four patients, 2 male and 2 female (aged 2-40 years, mean 16 years), with severe subglottic tracheal stenosis underwent segmental tracheal graft reconstruction. Immunosuppressant medications were not given to any patient. Follow-up ranged from 18 to 20 months. Three patients successfully underwent decannulation, and 1 patient had local infection and dislodgment of the intraluminal stent with subsequent restenosis. The postoperative tracheal lumen appeared to be near normal, with histologic evidence of normal respiratory epithelium at the grafted site. In conclusion, cryopreserved, irradiated tracheal homograft transplantation is a valuable alternative for subglottic tracheal reconstruction.

Photodynamic therapy in management of head and neck cancers and precancerous lesions.

Photodynamic therapy (PDT) is a new form of cancer treatment with low morbidity. In this study, PDT was evaluated for its effectiveness in management of recurrent or widespread precancerous lesions, primary cancers in inoperable sites, recurrent or residual cancers which were refractory to radiotherapy and chemotherapy, and advanced tumors in the head and neck. Fifty-one patients were treated over a period of 5 years. A 91.67 per cent complete response rate was observed for T1 tumors (primary and recurrence) with a recurrent rate of 27.27 per cent. Nasopharyngeal carcinoma was highly responsive to PDT since all T1 and T2 tumors responded completely. This was in contrast to cancers in the soft palate which failed in most cases possibly due to inadequate light dose distribution. PDT was remarkably effective in curing premalignant diseases (100% complete response rate). Postoperative PDT was equally effective in treating the microscopic residual malignancy. For advanced tumors, PDT in adjunct to conventional modalities could induce complete response in 5 out of the 10 patients and resolve symptoms in 4 cases. The mean follow-up time for this series was 28.3 months (range 3-66 months). In conclusion, PDT is a useful modality for the treatment of head and neck tumors and precancerous lesions presenting in forms or under conditions that posed considerable difficulties in management by conventional approaches.

Polymerase chain reaction study of Epstein-Barr virus in high risk group of nasopharyngeal carcinoma: a preliminary report.

The incidence of nasopharyngeal carcinoma (NPC) is relatively high in Thailand. Early diagnosis which leads to early treatment is crucial, in order to obtain a high salvage rate. Epstein-Barr virus (EBV) has long been known to be associated with nasopharyngeal carcinoma. Polymerase chain reaction (PCR) is a sensitive and specific technique for the detection of EBV genome in NPC. The first generation of members in the families of NPC patients is considered a high risk group. This study utilized the PCR technique as a screening test for early detection of EBV DNA in this group and also attempted to compare the result with that of IgA antibody level. The data was collected from July 1995 to 1996, this included 35 high risk volunteers, 15 males and 20 females. All subjects underwent telescopic examination and biopsies were performed to obtain specimens for PCR. Blood samples were also taken to determine serum titer of EBV IgA. All specimens studied were negative for EBV DNA and low IgA antibody titer obtained. The negative results implied that either the sample studied was inadequate to detect the low percentage of positivity of EBV in a high risk population or prolonged infection of EBV in nasopharyngeal mucosal cells is not necessary for initiation of NPC.

Fluorescence-guided biopsy in the diagnosis of an unknown primary cancer in patients with metastatic cervical lymph nodes.

This study was conducted to determine the effectiveness of fluorescence-guided biopsy in diagnosis of unknown primary cancers in the head and neck. Thirteen patients with biopsy-proven cervical node metastases were evaluated prospectively with laser-induced fluorescence (LIF) endoscopy in parallel to panendoscopy. Among the 13 positive sites suggested by LIF imaging, 5 were confirmed by histopathology as squamous cell carcinoma, 4 as dysplasia, 2 as inflammation, and 2 as normal. Panendoscopy with random biopsies located 2. The 2 cases of squamous cell carcinomas discovered conventionally were identified by histologic sections from ipsilateral tonsillectomy. In this series, the unknown primary cancers were localized by LIF imaging and conventional means at rates of 38.5% and 15.4%, respectively. The LIF imaging not only aided in revealing a greater proportion of occult primary cancers, but also helped in reducing the number of unnecessary biopsies. Fluorescence-guided biopsy diagnosis provides useful information for therapeutic planning with curative aim or for adequate palliation.

Photodynamic therapy for residual or recurrent cancer of the nasopharynx.

Adequate or effective treatments are not always available for most recurrent or residual nasopharyngeal cancers (NPC). Photodynamic therapy (PDT) using hematoporphyrin derivative (HpD) was evaluated for its effectiveness in treating patients, who conventionally failed, with curative or palliative intent. Thirteen patients were treated from March 1994 to November 1998. PDT was given to eradicate tumor cells, debulk tumor mass for other treatment options, and to resolve obstruction. Long-term tumor control could be achieved in 6 patients with localized lesions at T1-T2 stages. The mean disease free survival time was 25.8 months (range 5-61 months). For tumors beyond T2 stage (7 cases), PDT in combination with chemotherapy, laser surgery or radiotherapy induced complete response in 1 out of 5 patients (survival time = 40 months) and partial response in the rest (survival time = 16-37 months). In two patients who refused or were in tolerable to further treatment, PDT yielded useful palliative results (i.e. resolve nasal obstruction and epistaxis). On an overall basis, the average survival time for these patients with relatively advanced diseases was 24.7 months (range 9-40 months). Our study demonstrated that HpD-PDT could effectively control locally recurrent or residual NPC at T1-T2 stages and offered good palliation for more advances. Combined PDT and chemotherapy seemed to prolong survival time for a period longer than 2 years in T3-T4 tumors.

Laser-induced fluorescence imaging in localization of head and neck cancers.

Laser-induced fluorescence tumor imaging exploits the difference in tissue autofluorescence properties between normal and cancerous tissues. The effectiveness and reliability of fluorescence imaging with a lung imaging fluorescence endoscopy (LIFE) system for cancers in the head and neck were compared to those of white light endoscopy (WLE). Examinations by WLE and LIFE were conducted on 25 patients suspected for malignancy. Histologic diagnosis was confirmed by biopsy. Posttreatment evaluations were performed on 6 cancer patients identified by this study. By LIFE, all 16 cancerous lesions, including 2 occult cancers, were identified (100%), while WLE achieved only an 87.5% detection rate. LIFE (specificity 87.5%) was greatly helpful to WLE (specificity 50%) in differentiating inflammation from malignancy, though it failed to exclude granuloma. The results of this study suggest potential roles of LIFE in early detection, correct staging, and treatment evaluation of cancers in the head and neck.

Differences in in vitro photodynamic sensitivity among head and neck cancers.

This study was conducted to address the question of how cancers of different histologies of the head and neck region responded to photodynamic therapy (PDT). Five human cancer cell lines were investigated: two squamous cell carcinoma lines (pharynx and tongue), mucoepidermoid carcinoma (submaxillary gland), rhabdomyosarcoma (embryonic) and adenocarcinoma (colon). The cell lines were treated with haematoporphyrin derivative (HpD) at doses of 0.78-25Mug ml(-1), with excitation of the absorbed drug by a 'black light' source (340-380 nm). An MTT assay demonstrated different PDT responses among the various cell types. On the basis of LD(50), the sensitivity of the different cell lines was ranked as follows: adenocarcinoma> squamous cell carcinoma> rhabdomyosarcoma> mucoepidermoid carcinoma. The magnitude of the LD(50) was suggested by a drug uptake study to be governed in part by cellular levels of sensitizer and in part by intrinsic cell sensitivity. This study provided information that may help to identify the histological types of head and neck cancers that would respond favourably to PDT.

Are laryngeal papilloma virus-infected cells viable in the plume derived from a continuous mode carbon dioxide laser, and are they infectious? A preliminary report on one laser mode.

The purpose of this study was to determine the potential risk of transmitting viable viral infected cells as well as viral infectivity of laryngeal papilloma in the plume derived from a continuous mode carbon dioxide laser. Each of 10 juvenile recurrent laryngeal papilloma specimens was divided into two equal parts, and one part was irradiated with a carbon dioxide laser employing a continuous mode at the power setting of 10 watts with 0.5 mm spot size and a power density of 1667 W/cm2. The resultant laser plume was trapped and was cultured simultaneously with the other part of the specimen which served as the control. All irradiated specimens tested yielded negative culture results while all the control counterparts revealed viable cell growth. To detect the viral infectivity, laser plume was cultured with two separate cell systems, one was the porcine PS clone D cell line and the other normal mucosal cells obtained from the same patient, and to control these systems both cell lines were also designed to be infected with polio virus. Both cell lines in the viral infectivity testing systems revealed no sign of viral infection. The results suggest that papilloma virus-infected cells cannot survive the continuous mode of carbon dioxide laser irradiation. We primarily conclude that, to avoid airborne transmission of plume containing laryngeal papilloma viral-infected cells and infectious viral particles, the carbon dioxide laser parameters should be in a continuous mode with the power density equal to, or more than, 1667 W/cm2.

Photodynamic therapy in the treatment of head and neck cancers: a two-year experience.

This report describes the effectiveness of photodynamic therapy (PDT) in treating patients with widespread superficial premalignant and malignant lesions, primary and second primary, nonresponsive residual or recurrent cancers in head and neck. Twelve patients whose disease was at T1 stage responded completely. Severe dysplasia and field cancerous lesions involving a large area of oral mucosa (3 cases) also yielded excellent results. Average disease-free period was 13.6 months. The longest survival period was 2 years. All patients as mentioned are still alive without any relapse or recurrence. Combined PDT with other treatment was required to control T2-3 carcinomas. PDT adjunct, however, permitted the prescription of conventional treatment, i.e. radiotherapy or surgery, in a less morbid manner. No unacceptable treatment complications and skin photosensitivity were observed in this study. This indicated the potential role of PDT in the management of long-standing problems in head and neck cancers.

Nasopharyngeal carcinoma: results of treatment by radiotherapy vs chemotherapy plus radiotherapy.

To determine the efficacy of neoadjuvant chemotherapy over radiotherapy alone in locally advanced nasopharyngeal carcinoma, a prospective non-randomized study was performed from 1 January 1982 to 31 December 1985 at Ramathibodi Hospital, Thailand. There were 69 new cases who completed treatment and were followed up at least once. Thirty-three cases were treated by radical radiotherapy (RT) alone and 36 cases by chemotherapy (CT) + RT. CT were by the combination of cis-diamminedichloroplatinum II and 5 fluorouracil. Of 32 cases, 2 courses of CT were given before RT and 1 after. The other 4 received 3 courses prior to RT. For both groups, RT technique and dosage were similar. Follow-up time of both groups ranged from 6-104 months (mean 50.3, median 50) and 8-100 months (mean 52.2, median 54.5), and total failures were 18/33 and 13/36, respectively, with no statistical difference (p greater than 0.05). Estimated actual survival and disease free survival from Kaplan-Meier curves at 3 years were about 75 per cent vs 75 per cent and 65 per cent vs 65 per cent, respectively, with no statistical differences (Log-Rank test). Therefore, we concluded that induction chemotherapy had some benefit but no statistical significance over RT alone. However, the role of maintenance chemotherapy is now being studied.

Nasopharyngeal carcinoma: value of bone and liver scintigraphy in the pre-treatment and follow-up period.

Nasopharyngeal carcinoma (NPC) is a disease with a high potential of distant metastasis, especially to bone and liver. To evaluate the routine use of bone and liver scintigraphy in the evaluation of metastatic disease during the pre-treatment and follow-up period, 112 new cases of NPC were enrolled. The pre-treatment scintigraphs were performed at the time of staging evaluation, while the follow-up ones were performed once a year and whenever clinically indicated. At the pre-treatment period, 3/112 cases showed a true positive result, all at bony sites. At the 3 years follow-up, 10/83 and 8/83 cases respectively showed a true positive result in the bone and liver. All of the positive cases had definite symptoms and signs of metastases, which correlated well with the scintigraphic findings. All without clinical evidence showed a negative finding. Therefore, we conclude that, without clinical indication, routine bone and liver scintigraphy are of limited value.

Changes in T-staging of nasopharyngeal carcinoma by CT-scan.

To evaluate the value of computerized axial tomogram (CT-scan) of the nasopharynx in the management of patients with nasopharyngeal carcinoma (NPC), comparisons between clinical T-staging by means of indirect or direct nasopharyngeal examination, and CT-scan were performed in 101 cases. CT-scan has upstaged clinical T-staging in 83.9 per cent of Tx-T3 cases, or 80 per cent in Tx, 98 per cent in T1, 65.4 per cent in T2, and 50 per cent in T3 cases. CT-scan was also able to show the destruction of the base of the skull in 85.7 per cent of T4 cases. With regard to tumor extensions into the surrounding regions, the CT-scan proved to out-perform clinical T-staging by 82.2, 57.4, and 25.7 per cent respectively in superior, anterior, and lateral and inferior extensions. We, therefore, recommend that a CT-scan be done in every new case of NPC, because it provides more accurate T-staging, and more details of tumor extension, which is essential in the management of NPC, especially in the proper planning of radical radiotherapy.

Nasopharyngeal carcinoma: result of treatment with cis-diamminedichloroplatinum II, 5 fluorouracil, and radiation therapy.

Combined CT (CDDP + 5FU) and RT were given to 28 patients with NPC during July 1982-May 1985. Two, 1, 4, and 21 were in Stages I-IV (AJC), respectively. None had distant metastasis. Four did not complete the planned treatment, and one each had more or fewer CT courses than planned. The median duration of follow-up of surviving patients was 29 months (19-52,x 31.1). Objective response (CR + PR) at the primary lesion was 27/28 (96.4%), whereas CR was 23/28 (82%). CR + PR and CR of the regional nodes were 21/22 (95.5%) and 18/22 (82%) respectively. Remaining node in the 2 patients, who did not prematurely die were pathologically negative. Response at N site should therefore be 100% CR. Only patients with T3 (1/5) and T4 (3/13) lesions had residual disease at the T site after initial treatment. Salvage therapy was able to induce CR in all asymptomatic PR patients. There were 4 relapses, 2 at T, and 1 each at T + N and T + M sites. All M disease occurred in patients with huge and/or low cervical lymphadenopathy. Five patients died, one of an unrelated disease, and one each of T, M, T + N, and T + M diseases. The remaining 23 patients were still alive, and all except 3 were free of disease. Side effects, mainly from RT, were clinically acceptable. One had transient cervical myelitis. Myelosuppression was mild and of short duration. Activity of CT was seen at both T, and N sites after the upfront CT. Compared to our previous experience using RT alone, the result of this study suggested a positive role of CT in this disease. However, future prospective randomized trials are required to better define its role.

Premalignant changes in normal appearing epithelium in patients with squamous cell carcinoma of the upper aerodigestive tract.

Biopsy specimens of "normal" mucous membrane of patients susceptible to the effects of the carcinogens of tobacco revealed morphologic abnormalities on electron microscopic examination that were consistent with the concept that carcinogenesis is a multistep process of sequential neoplastic development extending over a long period of time. Such changes in the upper aerodigestive tract are probably tobacco induced and may be reversible if tobacco exposure is eliminated. Use of the electron microscope can provide the clinician with an accurate assay of the severity of mucosal alterations induced by tobacco. The ability to detect such morphologic abnormalities should provide another deterrant to smoking and a useful tool in the further study of these phenomena.