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.

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.

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.

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.

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.