Biomedical subjects

D Choy

Publications and source records attributed to D Choy.

At least 37 records · Page 2Linked to original sources

PubMed1996

Purified recombinant EBV desoxyribonuclease in serological diagnosis of nasopharyngeal carcinoma.

To evaluate applications of highly purified recombinant EBV DNAase in the diagnosis and prognosis of NPC, we tested sera from patients with NPC, other EBV-associated diseases and EBV-seropositive and -seronegative healthy subjects by immunoblotting and DNAase inhibitory assay. The results were compared with those obtained by the conventional immunofluorescence assays against the EBV-specified early antigens and capsid antigens. The antigenic specificity of the immunoblotting assay for IgG antibody against the viral enzyme, but not that for the IgA antibody, was correlated with DNAase-inhibitory activity of the sera and their titers of IgG antibodies against the viral early antigens. Purified IgA as well as IgG from NPC sera inhibited enzyme activity with similar efficiency. The use of highly purified viral DNase has increased the sensitivity of detection of the corresponding antibodies by immunoblotting, with the IgG antibody being detected in all but one, and IgA antibody in all but 2, of the 174 NPC sera tested. The IgG antibody was also commonly detected in the other groups of control sera, while the IgA antibody was detected in about 10% of African Burkitt's lymphoma and Algerian Hodgkin's lymphoma patients and less than 3% of the other control subjects. These results suggest that IgA antibody against recombinant EBV DNAase may be useful in the diagnosis of NPC, but the level of this antibody did not appear to be related to clinical stages of this cancer.

Animals↗

PubMed1996

The antiemetic efficacy of tropisetron plus dexamethasone as compared with conventional metoclopramide-dexamethasone combination in Orientals receiving cisplatin chemotherapy: a randomized crossover trial.

1. We report a single-blind randomized crossover trial comparing the efficacy of tropisetron plus dexamethasone (TROPDEX) vs conventional combination of metoclopramide, dexamethasone and diphenhydramine (METDEX) in prevention of acute and delayed vomiting in Chinese patients receiving high dose cisplatin. 2. Thirty-six consecutive patients with nasopharyngeal carcinoma were entered into the study, all received cisplatin at a dose range of 60-100 mg/m2. Patients were randomized in the sequence of antiemetic regimens used in two consecutive cycles. 3. The TROPDEX regimen consisting of tropisetron 5 mg i.v. and dexamethasone 20 mg i.v. given on day 1 of chemotherapy, followed by oral maintenance with tropisetron 5 mg daily and dexamethasone 4 mg twice daily from day 2 to 6. The METDEX regimen consisting of metoclopramide 1 mg kg-1 i.v., dexamethasone 20 mg i.v. and diphenhydramine 25 mg i.v. given before chemotherapy and then 2 hourly for two more doses on day 1, followed by oral metoclopramide 20 mg 6 hourly from day 2 to 6. 4. Complete control of acute vomiting was observed in 64% of patients with TROPDEX as compared with 14% with METDEX (P < 0.01). While complete plus major control of acute vomiting was observed in 84% with TROPDEX as compared with 58% with METDEX. The mean vomiting episodes on day 1 were 1.4 with TROPDEX as compared with 3.5 with METDEX (P < 0.01). There was, however, no significant difference between the two regimens in the control of delayed vomiting. 5. When patients randomized to TROPDEX in the second cycle were compared with those with TROPDEX in the first cycle, the antiemetic efficacy was reduced, with mean acute vomiting episodes of 2 in the former compared with 0.8 in the latter (P < 0.01). 6. The most common adverse effect observed was headache in TROPDEX (27%) and dizziness in METDEX (40%). 7. In conclusion, the antiemetic regimen TROPDEX is effective in Chinese patients receiving high dose cisplatin chemotherapy and is well tolerated. It is better than conventional METDEX regimen in the control of acute vomiting, but not in the control of delayed vomiting.

Antiemetics↗

PubMed1995

Treatment outcome and prognostic factors for primary nasal lymphoma.

PURPOSE: To report our experience managing a large series of Chinese patients with primary nasal lymphoma. PATIENTS AND METHODS: From January 1975 to December 1993, 100 patients (median age, 50 years) with newly diagnosed primary nasal lymphoma were studied. There were four low-grade, 62 intermediate-grade, nine high-grade, and 25 unclassifiable lymphomas. Immunophenotyping was performed in 45 patients: eight B cell, 35 T cell, and two uncertain. All cases of angiocentric lymphoma that were typed were T cell. Fifty-two patients had stage I disease, 15 had stage II, four had stage III, and 29 had stage IV. Only 15 patients had B symptoms (weight loss, night sweats, and/or fever), and 11 had bulky disease. Thirty-nine patients with clinically localized stage I and II disease received local radiotherapy alone (before 1980), and the remaining 28 stage I and II patients received combination chemotherapy followed by local radiotherapy. The 33 patients with advanced stage III and IV disease were given combination chemotherapy, and additional radiotherapy was given to five of them who had bulky local disease. RESULTS: Significantly higher complete remission rates were observed in patients with early stages of disease and those without B symptoms. Superior disease-free survival after complete remission was observed in patients with stage I/II disease. Univariate factors associated with a better overall survival included age less than 60 years, stage I disease, and absence of B symptoms. Survival was significantly better in the subgroup of patients with stage I disease. CONCLUSION: Patients with nasal lymphoma, especially those with advanced disease, seemed to have a poor prognosis, and their clinical outcome was not improved significantly by the use of chemotherapy instead of radiotherapy or the use of doxorubicin-containing chemotherapeutic regimens.

Adolescent↗

PubMed1994

The effect of loco-regional control on distant metastatic dissemination in carcinoma of the nasopharynx: an analysis of 1301 patients.

PURPOSE: This study evaluated the effect of loco-regional control on incidence of distant metastases in patients with nasopharyngeal carcinoma. METHODS AND MATERIALS: Retrospective analysis was performed on 1301 patients with nasopharyngeal carcinoma treated from 1976-1989 in our hospital. The effect of different prognostic indicators on distant metastases free survival (DMFS) was analyzed, including T stage, N stage, sex, and loco-regional control. The significance of loco-regional control in distant metastatic dissemination was further studied with period and subgroup analysis. Cox regression was performed to identify the independent prognostic variables. RESULTS: Patients with loco-regional relapse had significantly higher distant metastases rate than patients with loco-regional control (time-adjusted distant metastases rate at 5 years was 40.7% vs. 29.4%, p = 0.0012). By period analysis, the effect of loco-regional control on distant metastases was found to be significant in the first 2 years from diagnosis. Subgroup analysis showed that loco-regional relapse was associated with significantly higher distant metastases rate in patients with T1, N0, and N1 disease (p = 0.001, 0.001, 0.0226, respectively). The Cox regression model also confirmed loco-regional control as an independent prognostic indicator of distant metastases (p = 0.0001) besides T stage (p = 0.0006) and N stage (p = 0.0001). CONCLUSION: Loco-regional relapse is a significant risk factor for development of distant metastases. Further effort should be made to improve loco-regional control and to eradicate distant metastases.

Adolescent↗

PubMed1994

Radiotherapy for nasopharyngeal carcinoma: shielding the pituitary may improve therapeutic ratio.

PURPOSE: Nasopharyngeal carcinoma (NPC) is well known for its invasiveness and erosion of the base of the skull is not uncommon. Before the advent of computed tomography, the evaluation of the base of the skull was by plain radiography. Because of the low sensitivity of these investigations, traditional teaching has included the sphenoid sinus in the volume of irradiation. Increase in longevity of patients allows the manifestation and documentation of the long-term sequelae of irradiating the hypothalamic-pituitary axis and the temporal lobes. This study is an attempt to evaluate whether the hypothalamic-pituitary axis can be shielded from the target volume in a proportion of NPC patients. METHODS AND MATERIALS: One hundred fifty-two NPC patients with no evidence of erosion of the base of the skull and sphenoid, nor extension to the nasal fossa and ethmoid sinuses were randomized to receive standard radiotherapy covering the whole sphenoid sinus or radiotherapy using a modified technique that shields the pituitary and the anterior part of the hypothalamus. This modified technique also shields a large part of the lower temporal lobes that are otherwise covered by standard treatment portals. The characteristics and treatment of the two subgroups of patients were otherwise comparable. RESULTS: At a median follow-up of 31.5 months, the tumor control between the two subgroups of patients were comparable (p = 0.3928). However, 8 of the 71 patients in the unshielded group had developed symptomatic neuroendocrine complications, while none of the other group did (p = 0.0061). Two patients developed secondary hypothyroidism, one patient developed oligomenorrhoea associated with raised prolactin, and five patients developed temporal lobe necrosis. CONCLUSIONS: The protective effect on neuroendocrine complication of this shield was demonstrated at median follow-up of 31.5 months, and the local control was not jeopardized. Modification of treatment technique as presently described, which is applicable to one-third of NPC patients to improve the therapeutic ratio, is recommended for general use.

Adult↗

PubMed1994

Vaginal template implant for cervical carcinoma with vaginal stenosis or inadvertent diagnosis after hysterectomy.

PURPOSE: For cervical carcinoma patients with poor geometry for conventional intracavitary radiotherapy, a simple vaginal template for interstitial implantation as a substitute was used. This template has also been used to treat patients who had hysterectomy done without knowledge of an early tumor in the cervix, and for patients with recurrent disease. This is a report of the treatment results. METHODS AND MATERIAL: A total of 21 patients were treated over from July 1987 to June 1991 with this vaginal template implant forming part of the treatment, 12 of these were performed for vaginal stenosis. The applicator consists of a front piece and an end piece. Holes were drilled in the front piece to guide the implantation of the cervix or vaginal vault. The diameter of applicators varied from 2 cm to 3.5 cm. Depending on the diameter of the applicators, six to eight needles on the periphery, or eight peripheral plus one central needle were used. The activity of the needles were around 8 mCi with a total length of 5.5 cm. The end piece was locked onto the front piece by a bayonet-type locking device. The purpose of the end piece was two-fold: to make up the length of the whole applicator to fit the vagina and to keep the implanted needles in place without being extruded. The implantation was performed under general anesthesia. RESULTS: One of the twelve patients treated with the vaginal template implant for vaginal stenosis had relapsed centrally but subsequently died of intercurrent disease. Two other patients died of intercurrent disease at 26.2 and 41.9 months, respectively, without evidence of relapse. Nine other patients had been followed with no evidence of local relapse for 23.7 to 54.6 months. CONCLUSION: This vaginal template implantation is a satisfactory means of treating patients with vaginal stenosis and those who had hysterectomy done without knowledge of an early tumor in cervix.

Adult↗

PubMed1993

Computed tomography evaluation of neck node metastases from nasopharyngeal carcinoma.

PURPOSE: To study the role of computed tomography in the pre-therapy evaluation of nasopharyngeal carcinoma. METHODS AND MATERIALS: The computed tomography of 119 new patients of nasopharyngeal carcinoma were evaluated independent of clinical findings for neck node metastases, and then compared with clinical findings. Contrast enhanced axial scans were obtained at 5 mm intervals with the infraorbitomeatal line parallel to the gantry. Scans were obtained from the supra-sellar cistern to the C5 or C6 vertebra for the evaluation of the base of skull, nasopharynx, paranasopharyngeal space and the upper and mid neck. RESULT: The present study confirmed the disparity of nodal extent documented by clinical palpation and computed tomography. Of the 37 patients who have no clinically palpable node (N0), computed tomography showed nodal involvement in 11 (29.7%) of them, and they were up-staged from N0 to N1. Computed tomography showed multiple or bilateral nodes in seven (58.3%) of the 12 patients with AJC N1 disease and they were hence up-staged to N2. All together, there were 28 (23.5%) patients who have no computed tomography evidence of nodal involvement by tumor. In agreement with clinical experience, the most commonly involved nodal groups were the upper internal jugular and upper spinoaccessary, followed by the lateral retropharyngeal. The percentage of nodes which were not clinically palpable was roughly the same for different regions (15-30%), except, as expected, that all the retropharyngeal nodes were not palpable. The risk of harboring retropharyngeal node was proportional to the size of the largest node in the ipsilateral neck. CONCLUSION: A significant proportion of patients with clinically negative neck (N0) or AJC N1 disease will be upstaged by computed tomography, thus supporting its routine use in pre-therapy evaluation of nasopharyngeal carcinoma.

Head and Neck Neoplasms↗

PubMed1993

Transpalatal insertion of radioactive gold grain for the treatment of persistent and recurrent nasopharyngeal carcinoma.

PURPOSE: To evaluate the efficacy of radioactive gold grain implant via the split palate approach in the control of locally recurrent or persistent nasopharyngeal carcinoma. METHODS AND MATERIAL: Forty-three patients, 10 for persistent NPC, 28 for first relapse in the nasopharynx, and five for second relapse in the nasopharynx, were treated. The diameter of the tumors at the time of gold grain implant ranged from 0.5 to 5 cm, the number of gold grains inserted varied from 4 to 14, the median number was seven. RESULTS: There was no significant difference in the control of the primary tumor for persistent disease (80% at 5 years), first relapse (61% at 5 years) and second relapse (80% at 3 years), p = 0.8845. The difference in survival between the three subgroups of patients, however, was highly significant (p = 0.0040). Thirty patients had CT evaluation before gold grain implant and the tumor was found confined to the nasopharynx in 21, in the remaining nine patients erosion of the sphenoid sinus or other parts of the base of skull was noted. The difference in the control between those patients with tumors confined to the nasopharynx and those patients with extranasopharyngeal extension of tumor almost reached statistical significance (81% and 44% respectively at 5 years, p = 0.0554). For the six patients who developed local recurrence after gold grain implant and were evaluable for the pattern of failure, the recurrent tumors were considered originating from another region of the nasopharynx in four, and in-field failure in the other two cases. CONCLUSION: Radioactive gold grain implant as salvage treatment provides satisfactory control of persistent and recurrent nasopharyngeal carcinoma. The local control was better when the tumor was localized to the nasopharynx, thus underlines the importance of close follow-up for early recognition of relapse and persistent tumor. However, such patients still suffered from high incidence of regional and distant failure, the pathophysiology and management of which require further investigation.

Adult↗

PubMed1993

Dose-tumor response of carcinoma of cervix: an analysis of 594 patients treated by radiotherapy.

This is a retrospective study of 594 histologically proven carcinomas of the uterine cervix treated with radiotherapy alone between January 1970 and December 1986. The age of this group of patients ranged from 22 to 86 years, and the median age was 57 years. There were 544 (91.6%) patients with squamous carcinoma and 36 (6.1%) with adenocarcinoma. There were 24 (4.0%) patients who were treated by two sessions of intracavitary brachytherapy only using intrauterine tandem and vaginal ovoids; 513 (86.4%) patients received whole pelvis irradiation followed by two sessions of brachytherapy at 1-week intervals, with or without additional boost to the parametrium. The dose to point A ranged from 40 to 100.9 Gy for the patients with stage IB to IIIB disease. The 5- and 10-year survival for stages IB, IIA, IIB, IIIA, and IIIB were 90.0, 82.1, 72.0, 50.0, 51.5, and 86.9, 71.0, 67.5, 41.7, and 46.9%, respectively. There was no long-term survivor for stage IV disease; the median survivals for patients with stages IVA and IVB were 15.2 and 9.3 months, respectively. Dose response was demonstrated for stages IIB and III tumors; dose to point A greater than 85 Gy was associated with better central control (P = 0.0036 and 0.0234, respectively). However, further increase in dose to point A beyond 85 Gy was not associated with improvement in central control (P = 0.3128 and 0.3394, respectively, for stages IIB and III). It was also found that the occurrences of rectosigmoid and bladder complications were correlated with the rectal and point A dose. Thus, for these patients, there is no need to increase the dose to point A beyond 85 Gy so that the risk of radiation sequelae can be cut down.

Actuarial Analysis↗

PubMed1993

In-situ carcinoma adjacent to recurrent nasopharyngeal carcinoma. Evidence of a new growth?

Eighty biopsies from 74 patients with recurrent nasopharyngeal carcinoma diagnosed in the years 1988 to 1990 inculsive were reviewed. The overlying epithelium was assessed for the presence of in-situ malignant change using a Gomori reticulin stain in addition to the routine haematoxylin and eosin stain. In-situ change was seen in the overlying epithelium or adjacent epithelium in 11 of these biopsies from 10 patients (13.5%). These changes were extensive and where normal epithelium was seen there was an abrupt transition from the normal to abnormal epithelium. As patients treated for NPC sustain such a high risk of developing another new growth, close and careful follow up of these patients will allow a good opportunity for research into the carcinogenesis of this tumor.

Carcinoma in Situ↗

PubMed1993

Multicenter phase II trial of mitoxantrone in patients with advanced nasopharyngeal carcinoma in Southeast Asia: an Asian-Oceanian Clinical Oncology Association Group study.

PURPOSE: Patients with advanced nasopharyngeal carcinoma (NPC) have a high incidence of recurrence and often develop distant metastases despite local control. This prospective multicenter phase II trial was conducted to evaluate the safety and efficacy of Novantrone (mitoxantrone; Lederle Laboratories, Wayne, NJ) in the therapy of patients with advanced NPC. PATIENTS AND METHODS: One hundred eight patients with advanced NPC, namely, those with recurrent or persistent disease following primary radiotherapy, or newly diagnosed metastatic disease, were treated with mitoxantrone. Mitoxantrone was administered intravenously at an initial dose of 12 mg/m2 and repeated every 3 weeks, with dose escalation to a maximum of 14 mg/m2. The distribution of histologic subtypes was representative of NPC, with the majority being (61%) undifferentiated (or anaplastic) carcinoma. RESULTS: The overall response rate (complete response [CR] and partial response [PR]) was 25% (95% confidence interval, 17% to 33%). The median response duration, time to treatment failure, and survival duration were 140, 82, and 394 days, respectively. Histology (poorly differentiated squamous cell) was found to be the only important factor in predicting response (P = .04) based on a multivariate analysis of nine pretreatment characteristics. The major dose-limiting toxicity was leukopenia. The incidences of nausea/vomiting, alopecia, and stomatitis/mucositis were 34%, 6%, and 3%, respectively. None were severe. Two patients had asymptomatic, moderate Alexander-grade cardiotoxicity. CONCLUSION: This study represents a large, controlled multicenter trial of single-agent mitoxantrone in the treatment of advanced NPC. Mitoxantrone was well tolerated and produced an overall response rate comparable to that of other single-agent therapies used in the treatment of advanced head and neck cancer. Combination trials with mitoxantrone for advanced disease should be considered.

Adult↗

PubMed1993

Postoperative radiotherapy for carcinoma of the esophagus: a prospective, randomized controlled study.

METHODS: A prospective, randomized controlled study of radiotherapy after resection of esophageal carcinoma was carried out in 130 patients. Patients were stratified according to whether the resection was curative or palliative and were then randomized to receive postoperative radiotherapy or no additional treatment. Sixty patients underwent curative resection; 30 each were randomized into the radiotherapy group (CR + R) and the control group (CR). Seventy patients underwent palliative resection; 35 each were randomized into the radiotherapy group (PR + R) and the control group (PR). RESULTS: No complications occurred while the patients were undergoing radiotherapy treatment. On follow-up, complications in the intrathoracic stomach occurred in 24 patients (37%) who underwent radiotherapy compared with four patients (6%) in the control group (p < 0.0001). Seventeen of these 24 patients in the radiotherapy group had gastric ulceration and there were five deaths as a result of bleeding. Local recurrence developed significantly less frequently in the PR + R group compared with the PR group (seven patients [20%] vs 16 patients [46%]; p = 0.04); no difference was observed between CR + R and CR groups (10% and 13%, respectively). Intrathoracic recurrence occurred in fewer patients in the radiotherapy groups (CR + R and PR + R) compared with the control groups (CR and PR) (four patients vs 15 patients; p = 0.01). In patients with residual tumor in the mediastinum after resection, two (7%) of 29 patients who underwent radiotherapy died of tracheobronchial obstruction, compared with nine (33%) of 27 patients in the control groups (p = 0.03). No difference in local recurrence was observed for extrathoracic or anastomotic recurrence. Distant metastasis developed in 12 patients (40%) in the CR + R group, nine patients (30%) in the CR group (p = 0.59), 24 patients (69%) in the PR + R group, and 18 patients (51%) in the PR group (p = 0.22). The time of onset of metastasis was 5.1 months for the PR + R group, which was shorter than the 8.5 months for the PR group (p = 0.05). The time of onset of metastasis was similar for the CR + R and CR groups (9.9 months and 11.0 months, respectively; p = 0.76). The overall median survival of patients after postoperative radiotherapy (CR + R and PR + R) was 8.7 months, which was shorter than the 15.2 months for the control groups (CR and PR) (p = 0.02). CONCLUSIONS: The shorter survival of patients who underwent postoperative radiotherapy was the result of irradiation-related death and the early appearance of metastatic diseases. The role of postoperative radiotherapy is therefore limited to a specific group of patients with residual tumor in the mediastinum after operation, for whom radiotherapy can significantly reduce the incidence of local recurrence obstructing the tracheobronchial tree.

Adenocarcinoma↗

PubMed1992

Direct detection of Epstein-Barr virus in peripheral blood and comparison of Epstein-Barr virus genotypes present in direct specimens and lymphoblastoid cell lines established from nasopharyngeal carcinoma patients and healthy carriers in Hong Kong.

By means of a PCR assay, EBV was demonstrated directly in peripheral blood of previously infected individuals. The virus was detected in approximately 80% of specimens from EBV-seropositive individuals, but not in cord-blood lymphocytes by this method. When virus present in peripheral blood was compared to that observed directly in NPC biopsies or throat washings, it was distinct from that seen in biopsies in 4/15 cases (27%) and from that seen in throat washes in 1/22 cases (5%). The throat-wash virus differed from the biopsy virus in 3/20 cases (15%). The prototype F virus was found in 7/10 LCLs (70%) established from NPC patients' peripheral blood, but was only detected in 2/9 specimens (22%) directly analyzed by the PCR assay. This finding suggests selective isolation of prototype F EBV in spontaneous LCLs established from NPC patients.

Blotting, Southern↗

PubMed1992

Extent of nasopharyngeal carcinoma involvement inside the nasopharynx. Lack of prognostic value on local control.

A study on the use of fiberscopic examination and multiple biopsy specimens taken from the nasopharynx in the assessment of the extent of nasopharyngeal carcinoma (NPC) involvement inside the nasopharynx found that the involvement often was more extensive than the detected with conventional methods. In the current study, 247 patients with NPC were studied with the use of fiberscopic examination, and multiple biopsy specimens were taken from the superior wall, posterior wall, and lateral wall of the nasopharynx on both sides. It was confirmed that the tumor often involved the nasopharynx extensively. Also, the extent of primary tumor involvement inside the nasopharynx was correlated with the American Joint Committee (AJC) T stage and the degree of paranasopharyngeal extension of the tumor (P = 0.0100 and 0.0009, respectively), as well as with the size of the largest node and the lowest neck level involved by the node in the ipsilateral neck (P = 0.0005 and 0.005, respectively). However, the extent of primary tumor involvement inside the nasopharynx, expressed as either the number of the six standard sites or the number of the AJC subsites that were involved, had no predictive value on the control of the primary tumor (P = 0.3773 and 0.7794, respectively) at a median follow-up time of 27 months. Except when salvage brachytherapy is contemplated for persistent or recurrent NPC, the extent of primary tumor involvement inside the nasopharynx should not be routinely studied.

Actuarial Analysis↗

PubMed1992

Serous otitis media. An opportunity for early recognition of nasopharyngeal carcinoma.

In a prospective study of 271 new patients with nasopharyngeal carcinoma, 36 (13.3%) were found to have cranial nerve involvement. Serous otitis media (SOM) was found in 98 (41.4%) of 237 patients who had undergone complete otologic assessment. The local control of tumor and actuarial survival of three subgroups of patients, namely, 80 patients with SOM only, 11 patients with cranial nerve palsy only, and 18 patients with both SOM and cranial nerve palsy, were analyzed. The local control of tumor was better in patients with SOM alone than in those with cranial nerve palsy alone; those patients with both SOM and cranial nerve involvement had worse local control as well as survival. As SOM is not uncommon in the diagnosis of nasopharyngeal carcinoma, and adult-onset SOM is otherwise distinctly uncommon, this provides a good opportunity for early recognition and, perhaps, better control of nasopharyngeal carcinoma.

Actuarial Analysis↗

PubMed1992

Radiation therapy for nasopharyngeal carcinoma: histologic appearances and patterns of tumor regression.

Nasopharyngeal carcinoma is a common malignancy in Hong Kong and is treated by external radiotherapy. After 6.5 weeks of radiotherapy, the nasopharynx of 100 patients was examined and biopsy specimens were taken. All patients had repeated examination and biopsies done every 2 weeks until exophytic tumor was not seen and biopsy samples were negative on more than one examination of the nasopharynx. The interval between the cessation of therapy and biopsy ranged from 1 day to 11 weeks. Twenty-three patients had atypical findings and five of these had residual tumor requiring gold grain implantation brachytherapy. We identified a number of distinct pathologic changes in the post-biopsy material. Most of these changes disappeared 8 weeks after the cessation of therapy, but the presence of residual tumor after this time was an indication for subsequent therapy. If the date of the first biopsy was delayed until 6 weeks after the completion of radiotherapy, the percentage of atypical biopsies containing residual tumor rose from 21% to 55%. The posttreatment biopsy should be performed twice, as four patients had negative biopsy findings due to sampling error.

Adolescent↗

PubMed1992

Computed tomography of paranasopharyngeal spaces: normal variations and criteria for tumour extension.

In 137 normal CT scans of the nasopharynx, the parapharyngeal spaces at the nasopharynx level were asymmetrical in 30%. Their difference in width and distance from the midline was greater than 1 mm in 51% and 44% respectively. Fat was absent in the interpterygoid fascia in 20%, in the alar fascia in 28%, in the prevertebral space in 35%, and in the retropharyngeal space in 99% of patients. Assessment of tumour extension to the paranasopharyngeal space usually relies on symmetry and fascial fat planes. As either feature may not be present in the normal person, the relation of the tumour to two lines representing two fascial planes is proposed as a complementary method for the evaluation of tumour extension.

Adipose Tissue↗

PubMed1992

Effect of irradiation on middle ear effusion due to nasopharyngeal carcinoma.

The management of middle ear effusion by myringotomy and insertion of ventilation tubes in 75 adult patients was evaluated. In Group 1 the middle ear effusion was not related to nasopharyngeal carcinoma. The patients with nasopharyngeal carcinoma were subdivided into pre and post-radiotherapy groups (Group 2 and Group 3) according to the time of insertion of the ventilation tubes. Myringotomy and insertion of ventilation tubes achieved significant hearing gain in all three groups. The pre and post-radiotherapy groups had a higher post-operative infection rate than Group 1 (P greater than 0.01). The duration of a persistent tympanic membrane defect in the post-radiotherapy group was significantly longer than Group 1 (P = 0.03). The post-radiotherapy group had more perforations than Group 1 (P = 0.02). A total of 28% of ears in the post-radiotherapy group were discharging at the last visit. In view of the higher complication rate in the post-radiotherapy group, the role of myringotomy and insertion of ventilation tube is reassessed.

Adolescent↗