Management of local residual primary lesion of nasopharyngeal carcinoma (NPC): are higher doses beneficial?

Significance of boost dose for T4 nasopharyngeal carcinoma with residual primary lesion after intensity-modulated radiotherapy

BACKGROUND

Previous studies showed poorer survival in T4 disease with residual lesion. To evaluate the efficacy and toxicity of a boost dose for T4 nasopharyngeal carcinoma (NPC), patients with a residual primary lesion after intensity-modulated radiotherapy (IMRT).

METHODS

398 T4 NPC patients with residual primary lesions after radical IMRT were retrospectively reviewed. An IMRT boost dose of 4-6.75 Gy was delivered to the residual lesions in 2-3 fractions. Propensity score matching (PSM) was applied to balance potential confounders between groups (ratio, 1:2). The presence of Epstein-Barr virus (EBV) DNA in plasma after IMRT was used for risk stratification.

RESULTS

Patients who received boost radiation had significantly improved overall survival (OS) and local recurrence-free survival (LRFS) compared with those who did not (all P < 0.05). In the matched cohort, 3-year OS was 86.6% in the boost radiation group and 72.7% in the non-boost group (P = 0.022). Three-year LRFS was 93.4% in the boost radiation group and 83.5% in the non-boost group (P = 0.022). In the subgroup analysis, boost dose was shown to significantly improve 3-year OS (88.0% vs. 74.1%, P = 0.021) in the low-risk group (with undetectable plasma EBV DNA after IMRT). The administration of a boost dose also improved 3-year OS in the high-risk group (with detectable plasma EBV DNA after IMRT) (66.7% vs. 60.0%, P = 0.375). Multivariate analysis demonstrated that boost dose was the only protective prognostic factor.

CONCLUSION

The addition of a boost dose for T4 NPC patients with residual primary lesion after radical IMRT provides satisfactory tumor control and clinical benefit. Additional timely and effective strengthening treatments are recommended for patients with detectable levels of plasma EBV DNA after radiotherapy.

Fibre-optic endoscope-guided three-dimensional high-dose-rate interstitial brachytherapy for residual nasopharyngeal carcinoma after conventional external beam radiotherapy

Purpose

Locally residual nasopharyngeal carcinoma (NPC) is associated with increased risk of local failure, if additional treatment is not applied. The objective of this paper was to report the treatment effect of fibre-optic endoscope-guided three-dimensional high-dose-rate interstitial brachytherapy (3D HDR ISBT) boost, integrated with radical external beam radiotherapy (EBRT) for deep-seated NPC residual lesion.

Case report

A 52-year-old female, with a diagnosis of NPC and biopsy-proven low-differentiated squamous cell carcinoma (SCC) in left nasopharynx; the tumor size was 3.9 × 2.2 × 2.6 cm³ before treatment (T2N0M0). Three months after completion of EBRT, with a dose of 69.96 Gy in 33 fractions and concurrent chemotherapy with cisplatin, the residual tumor (3.3 × 1.8 × 2.2 cm³) was treated with 3D HDR ISBT boost under fibre-optic endoscope guidance. The brachytherapy dose was 14 Gy in 2 fractions of 7 Gy each.

Results

The removal of deep-seated residual tumor was securely achieved by 3D HDR ISBT, guided with fibre-optic endoscope. The refractory tumor in the patient healed uneventfully after fibre-optic endoscope-guided 3D HDR ISBT, without a recurrence during 26 months of follow-up.

Conclusions

Fibre-optic endoscope-guided 3D HDR ISBT boost could be an additional treatment strategy for locoregional residual NPC after radical EBRT, especially for deep invasive lesion.

Current treatment options for local residual nasopharyngeal carcinoma

OPINION STATEMENT

Local residual disease occurs in 7-13 % after primary treatment for nasopharyngeal carcinoma (NPC). To prevent tumor progression and/or distant metastasis, treatment is indicated. Biopsy is the "gold standard" for diagnosing residual disease. Because late histological regression frequently is seen after primary treatment for NPC, biopsy should be performed when imaging or endoscopy is suspicious at 10 weeks. Different modalities can be used in the treatment of local residual disease. Interestingly, the treatment of residual disease has better outcomes than treatment of recurrent disease. For early-stage disease (rT1-2), treatment results and survival rates are very good and comparable to patients who had a complete response after the first treatment. Surgery (endoscopic or open), brachytherapy (interstitial or intracavitary), external or stereotactic beam radiotherapy, or photodynamic therapy all have very good and comparable response rates. Choice should depend on the extension of disease, feasibility of the treatment, and doctor's and patient's preferences and experience, as well as the risks of the adverse events. For the more extended tumors, choice of treatment is more difficult, because complete response rates are poorer and severe side effects are not uncommon. The results of external beam reirradiation and stereotactic radiotherapy are better than brachytherapy for T3-4 tumors. Photodynamic therapy resulted in good palliative responses in a few patients with extensive disease. Also, chemotherapeutics or the Epstein-Barr virus targeted therapies can be used when curative intent treatment is not feasible anymore. However, their advantage in isolated local failure has not been well described yet. Because residual disease often is a problem in countries with a high incidence of NPC and limited radiotherapeutic and surgical facilities, it should be understood that most of the above mentioned therapeutic modalities (radiotherapy and surgery) will not be readily available. More research with controlled, randomized trials are needed to find realistic treatment options for residual disease.

3D-image-guided high-dose-rate intracavitary brachytherapy for salvage treatment of locally persistent nasopharyngeal carcinoma

Background

To evaluate the therapeutic benefit of 3D-image-guided high-dose-rate intracavitary brachytherapy (3D-image-guided HDR-BT) used as a salvage treatment of intensity modulated radiation therapy (IMRT) in patients with locally persistent nasopharyngeal carcinoma (NPC).

Methods

Thirty-two patients with locally persistent NPC after full dose of IMRT were evaluated retrospectively. 3D-image-guided HDR-BT treatment plan was performed on a 3D treatment planning system (PLATO BPS 14.2). The median dose of 16 Gy was delivered to the 100% isodose line of the Gross Tumor Volume.

Results

The whole procedure was well tolerated under local anesthesia. The actuarial 5-y local control rate for 3D-image-guided HDR-BT was 93.8%, patients with early-T stage at initial diagnosis had 100% local control rate. The 5-y actuarial progression-free survival and distant metastasis-free survival rate were 78.1%, 87.5%. One patient developed and died of lung metastases. The 5-y actuarial overall survival rate was 96.9%.

Conclusions

Our results showed that 3D-image-guided HDR-BT would provide excellent local control as a salvage therapeutic modality to IMRT for patients with locally persistent disease at initial diagnosis of early-T stage NPC.

Fractionated stereotactic radiotherapy for 136 patients with locally residual nasopharyngeal carcinoma

Background

To evaluate the efficacy and toxicity of fractionated stereotactic radiotherapy (FSRT) in patients with residual nasopharyngeal carcinoma (NPC).

Methods

From January 2000 to December 2009, 136 NPC patients with residual lesions after primary radiotherapy (RT) were treated by FSRT. The total dose of primary RT was 68.0-78.0 Gy (median, 70.0 Gy). The median time from the primary RT to FSRT was 24.5 days. Tumor volumes for FSRT ranged from 0.60 to 77.13 cm3 (median, 13.45 cm3). The total FSRT doses were 8.0-32.0Gy (median, 19.5 Gy) with 2.0-10.0 Gy per fraction.

Results

Five-year local failure-free survival (LFFS), freedom from distant metastasis (FFDM), overall survival (OS), and disease free survival (DFS) rates for all patients were 92.5%, 77.0%, 76.2%, and 73.6%, respectively. No statistical significant differences were found in LFFS, DFS and OS in patients with stage I/II versus stage III/ IV diseases. Nineteen patients exhibited late toxicity. T stage at diagnosis was a significant prognostic factor for OS and DFS. Age was a prognostic factor for OS.

Conclusion

FSRT after external beam radiotherapy provides excellent local control for patients with residual NPC. The incidence of severe late toxicity is low and acceptable. Further investigation of optimal fractionation regimens will facilitate reduction of long-term complications.

Excellent local control with stereotactic radiotherapy boost after external beam radiotherapy in patients with nasopharyngeal carcinoma

PURPOSE

To determine long-term outcomes in patients receiving stereotactic radiotherapy (SRT) as a boost after external beam radiotherapy (EBRT) for locally advanced nasopharyngeal carcinoma (NPC).

METHODS AND MATERIALS

Eight-two patients received an SRT boost after EBRT between September 1992 and July 2006. Nine patients had T1, 30 had T2, 12 had T3, and 31 had T4 tumors. Sixteen patients had Stage II, 19 had Stage III, and 47 had Stage IV disease. Patients received 66 Gy of EBRT followed by a single-fraction SRT boost of 7-15 Gy, delivered 2-6 weeks after EBRT. Seventy patients also received cisplatin-based chemotherapy delivered concurrently with and adjuvant to radiotherapy.

RESULTS

At a median follow-up of 40.7 months (range, 6.5-144.2 months) for living patients, there was only 1 local failure in a patient with a T4 tumor. At 5 years, the freedom from local relapse rate was 98%, freedom from nodal relapse 83%, freedom from distant metastasis 68%, freedom from any relapse 67%, and overall survival 69%. Late toxicity included radiation-related retinopathy in 3, carotid aneurysm in 1, and radiographic temporal lobe necrosis in 10 patients, of whom 2 patients were symptomatic with seizures. Of 10 patients with temporal lobe necrosis, 9 had T4 tumors.

CONCLUSION

Stereotactic radiotherapy boost after EBRT provides excellent local control for patients with NPC. Improved target delineation and dose homogeneity of radiation delivery for both EBRT and SRT is important to avoid long-term complications. Better systemic therapies for distant control are needed.

Nasopharyngeal carcinoma treated by radical radiotherapy alone: Ten-year experience of a single institution

PURPOSE

To report on our experience in the treatment of nasopharyngeal carcinoma (NPC) by radical radiotherapy alone in our institution during the last decade.

METHODS AND MATERIALS

From January 1990 to May 1999, 905 NPC patients were treated and were studied retrospectively. Radical radiotherapy was given to this cohort by conventional technique in a routine dose of 70-72 Gy to the primary tumor and metastatic lymph nodes. In case of residual primary lesion, a boost dose of 8-24 Gy was delivered by either 192Ir afterloading brachytherapy, fractionated stereotactic radiotherapy, conformal radiotherapy, or small external-beam fields.

RESULTS

The 5-year and 10-year local-regional control, overall survival, and disease-free survival rates were 81.7% and 76.7%, 76.1% and 66.5%, 58.4% and 52.1%, respectively. In case of residual primary lesions after a dose of 70-72 Gy of conventional external-beam radiotherapy (EBRT), an additional boost was able to achieve a local control of 80.8%, similar to that obtained with primary lesions that completely disappeared at 70-72 Gy (82.6%, p = 0.892).

CONCLUSIONS

The treatment results of radical EBRT followed by a boost dose to the residual primary tumor for nasopharyngeal carcinoma in our institution are promising.

Treatment outcomes and late complications of 849 patients with nasopharyngeal carcinoma treated with radiotherapy alone

PURPOSE

The objective of this study was to describe the treatment outcomes and treatment-related complications of nasopharyngeal carcinoma (NPC) patients treated with radiotherapy alone.

METHODS AND MATERIALS

Retrospective analysis was performed on 849 consecutive NPC patients treated between 1983 and 1998 in our institution. Potentially significant patient-related and treatment-related variables were analyzed. Radiation-related complications were recorded.

RESULTS

The 5-year overall and disease-free survival rates of these patients were 59% and 52%, respectively. Advanced parapharyngeal space (PPS) invasion showed stronger prognostic value than PPS invasion. Multiple neck lymph node (LN) involvement was demonstrated to be one of the most powerful independent prognostic factors among all LN-related parameters. External beam radiation dose more than 72 Gy was associated with significantly higher incidence of hearing impairment, trismus, and temporal lobe necrosis.

CONCLUSIONS

We recommend that the extent of PPS should be clarified and stratified. Multiple neck LN involvement could be integrated into the N-classification in further revisions of the American Joint Committee on Cancer stage. Boost irradiation is not suggested for node-negative necks. For node-positive necks, boost irradiation is indicated and a longer interval between initial and boost irradiation would reduce the incidence of neck fibrosis without compromising the neck control rate.

Lhermitte's sign among nasopharyngeal cancer patients after radiotherapy

BACKGROUND

Lhermitte's sign (LS) is a side effect of radiotherapy (RT) on the spinal cord and typically occurs shortly after the procedure has been conducted. When treating patients with cancer of the head and neck region with irradiation, it remains difficult to avoid exposing the cervical spinal cord to unintended radiation. In this study, we focused on nasopharyngeal cancer (NPC) alone and looked for various parameters that might influence the occurrence of LS associated with this disease after RT.

METHODS

From 1979 through 1990, 1171 patients with NPC completed RT either with or without chemotherapy at the Lin-Kou Medical Center, Chang Gung Memorial Hospital (CGMH), Tao-Yuan, Taiwan; the RT regimens for these treated patients were very similar. The nasopharyngeal tumor was treated to 75 Gy by photon teletherapy and after-loading brachytherapy. The neck lymphatics were irradiated with photon irradiation to 46.8 Gy and then boosted with electron beams to 10 to 30 Gy, in accordance with the patient's nodal status, either unilaterally or bilaterally. Every patient was followed monthly for the first 3 months after therapy and subsequently every 2 to 3 months for the next 2 years and, finally, every 6 months thereafter. At follow-up, a neurologic checkup of each patient was performed to determine whether any injury to the spinal cord or brain stem had arisen.

RESULTS

LS was observed for 121 patients (10.3%). The median development time for such signs was 3.0 months after the completion of RT (range, 0.2-72 months), and the appearance of such a sign lasted 1 to 82 weeks (median, 17 weeks). No statistically significant differences between the sexes were noted in the development of such a sign (p = .5263),or among various T classifications (p = .0757) and N classifications (p = .4412). The incidence of LS was significantly lower for those patients who had also received chemotherapy than it was for those who had not (p = .003), and it was also lower for patients older than 60 years than for those younger than 60 years (p = .0061). Of the subjects who did not undergo neck-lymphatic boosting or who had undergone only unilateral neck-lymphatic boosting, 7.2% had LS develop, whereas 11.5% of patients who had been boosted bilaterally had LS develop (p = .0285).

CONCLUSIONS

The incidence of LS associated with NPC and after RT was higher in patients who underwent bilateral neck-lymphatic boosting by electron beams than for those who underwent unilateral boosting or who did not undergo boosting. A correlation between increased incidence of LS and RT dose on the cervical spinal cord was noted when the cord dose exceeded 48.9 Gy. Therefore, wherever possible, a CT simulator and a three-dimensional treatment-planning system should necessarily be used to verify the dose distribution of electron-beam RT to diminish the chance of radiation overdose on the cervical cord.

Outpatient weekly 24-hour infusional adjuvant chemotherapy of cisplatin, 5-fluorouracil, and leucovorin for high-risk nasopharyngeal carcinoma

BACKGROUND

Distant metastasis rather than locoregional recurrence is the major site of failure after adequate radiotherapy in nasopharyngeal carcinoma (NPC). The aim of this study is to evaluate the toxicity and survival of outpatient weekly 24-hour infusion adjuvant chemotherapy for NPC patients with high-risk of distant failure.

METHODS

Our definition of high-risk NPC included patients with (1) 1992 AJCC staging system of N3, T4N2, or N2 with one of nodal size > 4 cm; (2) supraclavicular node metastasis; and (3) residual disease after radiotherapy or neck relapse. From August 1994 to August 1997, 41 NPC patients matching the preceding criteria agreed to receive weekly PFL (cisplatin 25 mg/m(2), 5-fluorouracil 1250 mg/m(2), and leucovorin 120 mg/m(2)) adjuvant chemotherapy for a total of 18 weeks. Clinical data of another 88 patients with similar disease status who did not receive adjuvant chemotherapy during the same period were collected and analyzed for comparison. Survival analysis was investigated by the Kaplan-Meier method and the Cox proportional hazards model.

RESULTS

A total of 700 weekly chemotherapy doses was delivered to 41 patients. The ratio of actual/planned dose delivery was 94.9%. Grade 3-4 toxicity of adjuvant chemotherapy included leucopenia (7.3%), anemia (2.4%), thrombocytopenia (2.4%), and nausea/vomiting (2.4%). After a median follow-up of 70 months, 26.8% (11 of 41) and 47.7% (42 of 88) of patients in PFL and no adjuvant chemotherapy groups had distant metastasis (p =.0247). The 5-year metastasis-free survival rates were 71.9% for the PFL group compared with 48.4% for no adjuvant chemotherapy patients (p =.0187). The 5-year overall survival rates were 53.7% (PFL group) and 38.3% (no adjuvant chemotherapy group), respectively (p =.0666). Multivariate Cox analysis showed PFL adjuvant chemotherapy was the independent factor that predicted metastasis-free survival after adjustment for other variables.

CONCLUSIONS

Outpatient weekly 24-hour continuous infusion PFL adjuvant chemotherapy is a well-tolerated regimen with promising results in high-risk NPC patients and merits investigation in phase III studies.

[Treatment of nasopharyngeal cancer: literature review]

The conventional radiotherapy and the associated treatments improved the prognostic of nasopharyngeal cancer. A better selection of the patients who must have a more aggressive treatment also probably contributed to this improvement. Even if a relation could be found between the locoregional relapse rate and the distant relapse rate, these two events remain often independent. It results from it that the improvement of local control rate necessarily does not result in a better control of the disease. The patients with a locally advanced tumor, with or not an invasion of the base of the skull and/or neurological symptoms, must have an aggressive locally treatment. This probably includes the increase in dose delivered to the tumor via a more conformational radiotherapy, a brachytherapy, radiotherapy in stereotaxic conditions or other techniques. Dose within the tumor must be at least 70 Gy and the prophylactic nodal dose, at least 50 Gy. CT scan and MRI are essential for delineating the volumes of interest. The protocols of hyperfractionated radiotherapy did not give convincing results. Association with chemotherapy allowed, on the other hand, an improvement of the prognostic locally advanced cancers. Neoadjuvant or adjuvant chemotherapy was largely used to attempt to limit the risks of systemic dissemination, but an improvement of results was not clearly demonstrated. An improvement of the rates of survival and control of the disease, on the other hand, was observed in a certain number of studies with the chemoradiotherapy. In the event of locoregional relapse, an aggressive attitude can allow the control of the disease in the absence of systemic dissemination. Salvage treatments are, however, disappointing for when distant relapse occurs which suggests a difference in chemosensitivity between primary tumor and metastasis.

Nasopharyngeal carcinoma

Nasopharyngeal carcinoma is usually present as locally advanced (stage III or IV) disease. Before 1980, the primary treatment was radiotherapy. The 5-year survival rate of patients with stage IVM0 across the world was less than 30%. Local, regional, and systemic recurrences are high in these patients and contributed to the poor survival. Sequential chemotherapy followed by radiotherapy (especially with the combination of cisplatin and 5-fluorouracil infusion for three courses) resulted in a 5-year survival rate of up to 55% in patients with stage IV disease. Concurrent single-agent cisplatin and radiotherapy improved 5-year survival rate to up to 55% in these patients. Total treatment with concurrent chemoradiotherapy followed by adjuvant cisplatin and 5-fluorouracil infusion resulted in 5-year survival rate of approximately 75%. Reversing the sequence of treatment by giving chemotherapy followed by concurrent chemoradiotherapy may improve the 5-year survival to up to 90%. In patients with recurrent disease or systemic metastases, the chances of salvage and long remission (many years) is approximately 15% to 20% with the use of adequate and effective chemotherapy. Newer agents, alone or concomitant with radiotherapy, are being evaluated in these patients.

Conformal radiotherapy and intensity-modulated radiotherapy--clinical data

Conformal radiotherapy (CRT) is based on three hypotheses: (i) a higher rate of local control can improve the survival rate; (ii) dose escalation can increase tumor control; and (iii) CRT allows the delivery of higher doses by decreasing the incidence of late effects. These postulates are now supported by several data. Three-dimensional conformal radiotherapy (3D-CRT) has markedly progressed since its introduction two decades ago. However, there are situations for which 3D-CRT cannot produce a satisfactory treatment plan because of complex target volume shapes or the close proximity of sensitive normal tissues. This is why intensity-modulated radiation therapy (IMRT) was introduced. Its aim is to overcome the limitations of 3D-CRT by adding modulators of beam intensity to beam shaping. IMRT can achieve nearly any dose distribution; however, the role of the planner remains crucial. CRT has been investigated mainly for prostate cancers and head and neck cancers. By and large, the clinical data, although still limited, seem to confirm the advantages of this type of radiotherapy. Dose escalation in prostate cancers improves the local control rate without increasing late effects and for this cancer site IMRT appears to be a significant advance over conventional 3D-CRT. In head and neck cancers the clinical data are still scarce but encouraging. CRT should be investigated in breast cancers with the aim of reducing the incidence of late effects. The available data underline the great potential for major progress in 3D-CRT and IMRT. The techniques are still costly and time consuming, nevertheless they merit investigation since their cost should decrease. Efforts should be concentrated on the specification of robust optimization criteria, taking into account clinical and radiobiological data.

Improved local control for early T-stage nasopharyngeal carcinoma--a tale of two hospitals

PURPOSE

To study the efficacy of intracavitary brachytherapy (ICT) in early T-stage nasopharyngeal carcinoma (NPC).

METHODS AND MATERIALS

All early T-stage (T1 and T2 nasal cavity tumour) NPC treated with a curative intent up to 1996 were analyzed (n=743), 163 from the Prince of Wales Hospital (PWH) and 25 from Tuen Mun Hospital (TMH) were given ICT after radical external radiotherapy (ERT; group A). They were compared with 555 patients treated with ERT alone (group B). The radiotherapy techniques were identical between the two hospitals. The ERT delivered the tumoricidal dose (uncorrected biological equivalent dose (BED)-10, > or = 75 Gy) to the primary tumour, and this did not differ in technique or dosage between the two groups. The ICT delivered a dose of 18-24 Gy in three fractions over 15 days to a point 1 cm perpendicular to the midpoint of the plane of the sources.

RESULTS

The local failure was significantly less (crude rates, 6.9 vs. 13.0%; 5-year actuarial rates, 5.8 vs. 11.7%) and the disease-specific mortality was significantly lower (crude rates, 13.8 vs. 18.9%; 5-year actuarial rates, 12.2 vs. 15.2%) in group A compared with group B. ICT was the only significant independent prognostic factor predictive of fewer local failures. When ICT was excluded from the Cox regression model, the total physical dose or the total BED-10 uncorrected for tumour repopulation became significant in predicting the ultimate local failure rate. The two groups were comparable in the rate of the chronic radiation complications. A significant dose-tumour-control relationship existed, plotting the local failure as a function of the total physical dose or the total BED.

CONCLUSIONS

Supplementing ERT, which delivered the tumoricidal dose (uncorrected BED-10, > or = 75 Gy), with ICT significantly enhanced ultimate local control in early T-stage (T1/T2 nasal infiltration) NPC. A significant dose-tumour-control relationship exists above the conventional tumoricidal dose level.

Three-dimensional small-volume irradiation for residual or recurrent nasopharyngeal carcinoma

PURPOSE

To minimize side effects and to achieve a high local control rate, three-dimensional (3D) small-volume irradiation was used for locally residual or recurrent nasopharyngeal carcinoma.

METHODS AND MATERIALS

Between July 1992 and March 1998, 18 tumors (12 residual and 6 local recurrent cases) were treated with 3D planned small-volume irradiation. The total dose (i.e., the dose of conventional radiotherapy plus that of the 3D irradiation) was 78.4 Gy (74.8-91.0 Gy) in its mean value for residual disease and 105.0 Gy (94.8-125 Gy) for recurrence. The mean value of the 90% isodose volume was 40.3 cc (8.0-94.0 cc). The mean follow-up period from the start of the boost or re-irradiation was 39 months.

RESULTS

The 3-year local control rate of the 12 residual tumors was 70%. Of 9 T4 residual tumors, 7 were controlled at a follow-up period between 17 and 70 months (median of 42 months). Of 6 recurrent tumors treated with re-irradiation, 3 were controlled at a follow-up period between 7 and 28 months. In the case of booster therapy, trismus occurred in 1 patient with a total dose of 91 Gy. Among the patients receiving re-irradiation, a temporary ulceration of the nasopharyngeal mucosa developed in 1 patient with a total dose of 111 Gy.

CONCLUSION

3D small-volume irradiation was effective and safe in treating residual or recurrent nasopharyngeal carcinoma.

Brachytherapy for primary and recurrent nasopharyngeal carcinoma: 20 years' experience at Long Beach Memorial

PURPOSE

We evaluated treatment outcomes of patients with mostly locally advanced primary and recurrent cancer of the nasopharynx managed with interstitial and intraluminal brachytherapy.

METHODS AND MATERIALS

This is a retrospective analysis of 56 patients with cancer arising from the nasopharynx treated with interstitial and intracavitary afterloading brachytherapy from 1978 to 1997. Patients were divided into three treatment groups: 15 patients with primary cancer (Group 1), 34 patients with recurrent or persistent disease (Group 2), and 7 patients with cancer in the nasopharynx who had history of previous definitive radiation therapy to the nasopharynx for head and neck cancer (Group 3). Fifty-three percent of patients in Group 1 had 1992 AJCC Stage IV disease, and 49% of patients in Groups 2 and 3 had extensive disease (defined as T3, T4, or parapharyngeal extension). Group 1 received megavoltage radiation to 50-60 Gy followed by a boost to the primary site and neck (in cases of persistent neck disease) with a combination of interstitial and intracavitary brachytherapy (mean dose 33-37 Gy). Five patients received chemotherapy, and 6 patients received hyperthermia. Groups 2 and 3 patients were treated with brachytherapy implants (mean dose 50-58 Gy) without external beam radiation. Twenty-five patients received chemotherapy either before or during radiation, and 21 patients received hyperthermia.

RESULTS

The overall survival at 2, 5, and 10 years for patients in Group 1 was 79%, 61%, and 61%, respectively, and for patients in Groups 2 and 3 combined was 48%, 30%, and 20%, respectively. Cause-specific survival at 2, 5, and 10 years was 87%, 74%, and 74%, respectively, for patients in Group 1; and 82%, 60%, and 60%, respectively, for patients in Groups 2 and 3. Local control at 2, 5, and 10 years was 93%, 93%, and 77%, respectively, for patients in Group 1; and 81%, 59%, and 49%, respectively, for patients in Groups 2 and 3. Control in the neck at 2, 5, and 10 years was achieved in 93%, 93%, and 93% of patients, respectively, in Group 1; and 88%, 81%, and 81%, respectively, for patients in Groups 2 and 3. Disease-free survival was 87%, 74%, and 62%, respectively, for patients in Group 1, and 56%, 41%, and 34%, respectively, for patients in Groups 2 and 3. There were 4 peri-operative deaths. One death (2%) was attributable to the development of late complications. Forty-five percent of patients experienced some form of late complications.

CONCLUSION

Interstitial afterloading brachytherapy can provide effective treatment for nasopharyngeal cancers, especially for locally persistent/recurrent and locally extensive lesions.

Skull-base invasion of nasopharyngeal carcinoma: magnetic resonance imaging findings and therapeutic implications

PURPOSE

To evaluate the value of skull-base abnormality on MRI for predicting local recurrence in nasopharyngeal carcinoma.

MATERIALS AND METHODS

Between November 1988 and February 1997, 48 patients with NPC were examined with both MRI (1.5 T) and CT prior to radiation therapy. T classification (1987 UICC) based on physical examination and CT findings were T1 in 3 cases, T2 in 22, T3 in 9, and T4 in 14. On MRI, low-intensity tissue with Gd enhancement in the marrow of the skull was considered to be a suspicious finding of skull-base invasion. CT simulation was performed in all patients. The total dose to the primary tumor was 60-75 Gy (mean, 67 Gy). The mean follow-up period was 42 months.

RESULTS

All 14 T4 patients had abnormal tissue in the marrow of the skull base on MRI. Thirty-eight percent (13 of 34) of T1-3 patients were suspected to have skull-base invasion based on MRI (0% for T1, 27% [6 of 22] for T2, and 78% [7 of 9] for T3). The 5-year local control rate was significantly different between T1-3 and T4 tumors (97% vs. 69%, p < 0.025) but was not different by the presence of the MRI abnormality in the skull base.

CONCLUSION

Skull-base invasion suspected solely by MRI does not relate to local recurrence provided that careful treatment planning is performed with the aid of MRI and CT simulator.

Intracavitary brachytherapy significantly enhances local control of early T-stage nasopharyngeal carcinoma: the existence of a dose-tumor-control relationship above conventional tumoricidal dose

PURPOSE

To study the efficacy of intracavitary brachytherapy (ICT) in early T-stage nasopharyngeal carcinoma (NPC).

METHODS AND MATERIALS

All T1 and T2 (nasal infiltration) NPC treated with a curative intent from 1984 to 1996 were analyzed (n = 509). One hundred sixty-three patients were given ICT after radical external radiotherapy (ERT) (Group A). They were compared with 346 patients treated by ERT alone (Group B). The ERT delivered the tumoricidal dose (uncorrected BED-10 > or =75 Gy) to the primary tumor and did not differ between the two groups in technique or dosage. The ICT delivered a dose of 18-24 Gy in 3 fractions over 15 days to a point 1 cm perpendicular to the midpoint of the plane of the sources. ICT was used to treat local persistence diagnosed at 4-6 weeks after ERT (n = 101) or as an adjuvant for the complete responders to ERT (n = 62).

RESULTS

The two groups did not differ in patients' age or sex, rate of distant metastasis, rate of regional failure, overall survival, or the follow-up duration. However, Group A had significantly more T2 lesions and Group B had significantly more advanced N-stages. Local failure was significantly less (crude rates 6.75% vs. 13.0%; 5-year actuarial rates 5.40% vs. 10.3%) and the disease-specific mortality was significantly lower (crude rates 14.1% vs. 21.7%; 5-year actuarial rates 11.9% vs. 16.4%) in Group A compared to Group B. Multivariate analysis showed that the ICT was the only significant prognostic factor predictive for fewer local failures (Cox regression p = 0.0328, risk ratio = 0.49, 95% confidence interval (95% CI) = 0.256-0.957). However, when ICT was excluded from the Cox regression model, the total physical dose or the total BED-10 uncorrected for tumor repopulation during the period of radiotherapy became significant in predicting ultimate local failure rate. The two groups were comparable in the incidence rates of each individual chronic radiation complication and the actuarial cumulative rate of the chronic radiation complications, with the exception of chronic radiation nasopharyngeal ulceration/necrosis which occurred in 10 patients in Group A and 1 patient in Group B. Headache (n = 4) and foul smell (n = 8) consequential to ulceration/necrosis were mild and manageable by conservative means. A significant dose-tumor-control relationship existed when local failure was studied as a function of the total physical dose or the total biological equivalent dose (linear quadratic equation, alpha/beta = 10) uncorrected for tumor repopulation during the time course of the radiotherapy.

CONCLUSIONS

Supplementing ERT which delivered tumoricidal dose (uncorrected BED-10 > or =75 Gy), ICT significantly enhanced ultimate local control and avoided the necessity for morbid salvage treatments in early T-stage (T1/T2 nasal infiltration) NPC. The slight increase in chronic radiation ulceration/necrosis after ICT was acceptable with mild and manageable symptoms. Other late complications were not increased. A significant dose-tumor-control relationship exists above the conventional tumoricidal dose level.

What is the significance of nasal involvement in nasopharyngeal carcinoma?

PURPOSE

The purpose of this study was to differentiate the patterns of nasal fossa involvement in nasopharyngeal carcinoma (NPC) and to clarify its prognostic influence on local control and survival after radiation therapy.

METHODS AND MATERIALS

Between November 1989 and July 1991, 218 patients with histologically proven local-regional NPC were treated with radiotherapy following the protocol at the Department of Radiation Oncology, Cancer Hospital, Shantou University School of Medicine. All patients had pretreatment CT scans. Fiberoptic endoscopic examination was performed every week during treatment and at the time of every follow-up visit to define the initial extent of disease and to evaluate treatment response. No chemotherapy or brachytherapy was given.

RESULTS

Of the 218 patients, 87 had nasal involvement. Sixty of them had a pattern of mucosal infiltration (MI), another 27 had an exophytic protruding (EP) component. The likelihood of residual disease after irradiation, the local relapse rate, 5-year freedom from progression rate (FFP), and death rate associated with local relapse (DRALR) of MI and EP were 36.7% vs. 3.7%, 30.0% vs. 7.4%, 26.7% vs. 51.8%, and 25.0% vs. 3.7% with p<0.004, p<0.005, p<0.02, and p<0.03, respectively. Multivariate analysis in this selected group demonstrated that infiltration of nasal fossa mucosa was an independent prognostic factor on primary control and freedom from progression.

CONCLUSION

Differentiation of nasal fossa involvement according to MI or EP is of value in predicting the outcome of treatment. We suggest that only the MI group should be considered as nasal involvement in the staging of NPC.

The time course of histologic remission after treatment of patients with nasopharyngeal carcinoma

BACKGROUND

The objective of this study was to define the time course of histologic remission and to evaluate the prognostic significance of delayed histologic remission of patients with nasopharyngeal carcinoma (NPC).

METHODS

Between 1986-1994, 803 patients underwent serial postradiotherapy nasopharyngeal biopsies. Patients with positive histology underwent repeated biopsies every 2 weeks until the biopsies were found to be negative or, if remission did not occur by the 12th week after radiotherapy, treatment was initiated for persistent disease. Patients with positive histology found after the fifth week but who achieved spontaneous remission before the twelfth week were considered to have delayed histologic remission. Negative histology by the sixth week was considered early histologic remission. The outcome of patients with delayed histologic remission, early histologic remission, and persistent disease were compared.

RESULTS

Six hundred and seventeen patients (76.8%) had negative histology within 12 weeks of the completion of radiotherapy and 55 (6.9%) had persistent disease at Week 12. In 131 patients (16.3%) spontaneous remission was observed in repeat biopsies after initial positive histology. With increasing time after radiotherapy, the incidence of positive histology decreased but more patients were found to have persistent disease. Patients with early and delayed histologic remission had 5-year NPC control rates of 82.4% and 76.8%, respectively (P = 0.35) versus a 40% NPC control rate among patients with persistent disease (P < 0.001). The 5-year survival rates were 75.3%, 79.4%, and 54.2%, respectively, for the 3 groups (P < 0.001).

CONCLUSIONS

A high proportion of early positive histology remitted spontaneously. Delayed histologic remission in NPC patients is not a poor prognostic factor and additional treatment is not necessary. A confirmatory biopsy at 10 weeks is recommended before the initiation of salvage treatment.

Radiation-induced bilateral optic neuropathy in cancer of the nasopharynx. Case failure analysis and a review of the literature

CASE REPORT

A case history of unanticipated radiation-induced bilateral optic neuropathy, 18 months after induction chemotherapy and radiation therapy for a locally advanced nasopharyngeal carcinoma, is presented. Retrospective reanalysis of the radiation therapy technique, with emphasis on the doses received by the optic pathway structures, was performed. These re-calculations revealed unexpectedly high doses in the range 79 to 82 Gy (cumulative external and brachytherapy dose) at the level of the optic nerves, which explained the observed radiation injury.

CONCLUSION

Routine implementation of computed tomography for 3D dose planning purposes is therefore advocated. Review of the current literature confirms the importance of 3D dose planning in avoiding this complication and high-lights the role of MRI in establishing the diagnosis of radiation-induced optic neuropathy.

Early stage nasopharyngeal carcinoma: radiotherapy dose and time factors in tumor control

OBJECTIVE

To evaluate radiotherapy dose and length of treatment in the control of early stage nasopharyngeal carcinoma (NPC) treated with a combination of external radiotherapy and brachytherapy,

MATERIALS & METHODS

We reviewed the records of 133 patients with early stage nasopharyngeal carcinoma (stage I or II, AJC/UICC staging system) who received definitive radiotherapy in Chang Gung Memorial Hospital from 1979 to 1991. The median follow-up time was 7.1 years with a minimum of 2 years. All patients were treated with megavoltage external radiotherapy to the nasopharynx area (63-72 Gy) followed by high dose rate intracavitary brachytherapy (5-16.5 Gy in one to three fractions, spaced 1-2 weeks apart). The median total dose and time of irradiation was 75 Gy (69.8-81.4 Gy) and 11.6 weeks (7.8-20 weeks) respectively. Survival analysis was used to examine the effect of several variables on prognosis.

RESULTS

The 5-year rates were 86.4% for local control, 84.7% for disease free survival, 88.5% for actuarial survival and 84.2% for overall survival. The treatment group (combination of time and dose of irradiation) was the most important prognostic factor according to Cox's proportional hazard model. Patients receiving radiation at a total dose of < or = 75 Gy completed in < 12 weeks showed the best prognosis.

CONCLUSION

Treatment time and total treatment dose are both important factors in treating early stage NPC. Decreasing the total radiation time to < 12 weeks and not exceeding a radiation dose of 75 Gy gave the best results.

Carcinoma of the nasopharynx treated by radiotherapy alone: determinants of distant metastasis and survival

PURPOSE

This retrospective study was conducted to identify the prognostic factors for distant metastasis and survival in a population of 378 patients with nasopharyngeal carcinomas treated by radiation therapy alone.

MATERIALS AND METHODS

All patients were treated at the University of Texas M.D. Anderson Cancer Center between 1954 and 1992, following a consistent dose and volume prescription policy. There were 286 males and 92 females. The median age was 52 years (range: 16-86 years). The majority of the patients were white Caucasians (282 patients,75%). Tumors were classified as squamous cell carcinomas (193; 51%), lymphoepitheliomas (154; 41%), or unclassified carcinomas (31, 8%). Three fourths of the patients presented with AJCC Stage IV disease (T4, N0-3, 118 patients; T1-3, N2-3 164 patients). The treatment techniques included opposed lateral fields with or without an anteroposterior or an anterior oblique pairs for dose supplementation to the primary site. Average total doses per T-stage ranged between 60.2 and 72.0 Gy. Median follow-up time was 10 years (range 0.3 to 28.6 years).

RESULTS

A total of 103 patients (27%) developed distant metastases at a median time of 8 months (range: 1-90 months). Actuarial rates for distant metastasis were 30%, 32%, 32% at 5, 10, and 20 years, respectively. Actuarial rates for disease specific survival at the same time points were 53%, 45%, and 39% with 184 patients (49%) dying of their nasopharyngeal cancer. Advanced T-stage, N-stage, and non-lymphoepithelioma histology were independent adverse prognostic factors for disease specific survival. Advanced N-stage and low neck disease were independent adverse prognostic factors for distant metastasis with a very high rate of distant metastases for those patients who presented with both adverse factors (relative risk 7.86). On average, patients with distant metastasis lived 5 months after they were diagnosed with metastatic disease (range: 0-172 months), although four patients (4%) survived more than 5 years after diagnosis.

CONCLUSIONS

This study demonstrates good long term survival rates after definitive radiotherapy for patients with nasopharyngeal carcinomas. Patients with advanced and lower neck disease have the highest risk of developing distant failures. Such patients can be considered the reference risk group to test the value of adjunctive chemotherapy.

Carcinoma of the nasopharynx treated by radiotherapy alone: determinants of local and regional control

PURPOSE

This retrospective study was conducted to review the results of treatment and to identify prognostic factors for local and regional control in a population of 378 patients with nasopharyngeal carcinomas treated in a single institution by radiation therapy alone.

METHODS AND MATERIAL

All patients were treated at The University of Texas M. D. Anderson Cancer Center between 1954 and 1992 following a consistent treatment philosophy but with evolving technique. There were 286 males and 92 females with a median age of 52 years (range: 16-86 years). The majority of the patients were Caucasian (282 patients, 75%). Thirty-two patients (8%) had one or more cranial nerve deficits. Three-fourths of the patients presented with AJCC Stage IV disease (T4, N0-3, 118 patients; T1-3, N2-3 164 patients). Histologically, 193 tumors (51%) were squamous cell carcinomas, 154 (41%) lymphoepitheliomas, and 31 (8%) unclassified carcinomas. Average total dose varied with T-stage and ranged from 60.2 to 72.0 Gy. Median follow-up time was 10 years.

RESULTS

For the entire population the 5-, 10-, and 20-year actuarial survival rates were 48, 34, and 18%, respectively, with 184 patients (49%) dying of nasopharyngeal cancer. Actuarial control rates at 5, 10, and 20 years were 71, 66, and 66% for the primary site and 84, 83, and 83% for the neck. A total of 100 patients (26%) had local failures and 51 patients (13%) had regional failures with a median time to recurrence of 8.2 months and 13 months, respectively. Advanced T-stage, squamous histology, and presence of cranial nerve deficits were poor prognostic factors for local control in both univariate and multivariate analyses. N-stage and tumor histology were significant factors for neck control. Treatment year, total dose within the ranges used, and duration of treatment did not have any significant effect on local or regional control. The actuarial incidence of Grade 3-5 late complications was 16, 19, and 29% at 5, 10, and 20 years, respectively. Twelve patients (3%) died of treatment-related complications; all but one fatal complication occurred before 1971 and the other in 1976.

CONCLUSIONS

This study shows very good long-term local and regional control rates for nasopharyngeal carcinomas after definitive radiotherapy and establishes a benchmark for newer treatment strategies. Improvements in treatment technique over the years have dramatically reduced the frequency of severe late complications. Patients with advanced stage tumors and differentiated squamous histology have a relatively poor prognosis when treated with conventional radiotherapy and are candidates for dose escalation or combined modality studies.

The role of brachytherapy in early-stage nasopharyngeal carcinoma

PURPOSE

To present the treatment results and assess the optimal radiation dose and the role of brachytherapy in early stage nasopharyngeal cancer (NPC).

METHODS AND MATERIALS

One hundred eighty-three patients with Stage I and II (American Joint Committee on Cancer Staging System, 1987) NPC completed the planned radiotherapy in our institution from 1979 to 1991. In 133 patients, radiotherapy was given to the nasopharynx by external beam to 64.8-68.4 Gy. Further boost was done by high dose rate (HDR) brachytherapy for 5-16.5 Gy in one to three fractions. For the remaining 50 patients, a course of external radiotherapy to the nasopharynx for 68.4-72 Gy was given to nasopharynx. Age (>40 or not), sex, neck boost or not, brachytherapy, and irradiation dose were analyzed to determine significant factors that influence the probabilities of local control and actuarial survival.

RESULTS

The 5-year disease-specific survival was 85.8% and local control was 83%. Only the brachytherapy and irradiation dose significantly affected the results. The use of the brachytherapy had significant impact on overall survival and local control. Furthermore, we compared the prognostic effect of various radiation dosage among Group I of 50 patients (<72.5 Gy, no brachytherapy, excluding four patients who received brachytherapy), Group II of 71 patients (72.5-75 Gy; one to two fractions of brachytherapy), and Group III of 58 patients (>75 Gy; three fractions of brachytherapy). Five-year disease-specific survival rates of Group I, Group II, and Group III were 77, 95.5, and 82.4%, respectively. Five-year local control rates were: 73.7, 93.9, and 79.5%. We found that the Group II had the best actuarial survival and local control rate (log-rank test,p < 0.05). Most patients receiving brachytherapy encountered foul odor because of nasopharynx crust; 12 of them had palate or sphenoid sinus floor perforation or nasopharynx necrosis. None of the patients without brachytherapy experienced the same complications.

CONCLUSIONS

The optimal radiotherapy dose to the nasopharynx area in early stage NPC may be within 72.5 to 75 Gy by our treatment protocol. A dose of more than 75 Gy did not have significant local control or survival advantage. The use of brachytherapy to elevate radiation dose had significant local control and survival benefit for early stage NPC patients, but the fractionation size should be decreased to reduce the complications.

Head and neck cancer

This synthesis of the literature on radiotherapy for head and neck cancer is based on 424 scientific articles, including 3 meta-analyses, 38 randomized studies, 45 prospective studies, and 246 retrospective studies. These studies involve 79174 patients. The literature review shows that radiotherapy, either alone or in combination with surgery, plays an essential role in treating head and neck cancers. When tumors are localized, many tumor patients can be cured by radiotherapy alone and thereby maintain full organ function (1, 2). Current technical advancements in radiotherapy offer the potential for better local tumor control with lower morbidity (3). This, however, will require more sophisticated dose planning resources. To further improve treatment results for advanced tumors, other fractionation schedules, mainly hyperfractionation, should be introduced (5). This mainly increases the demands on staff resources for radiotherapy. The combination of radiotherapy and chemotherapy should be subjected to further controlled studies involving a sufficiently large number of patients (4, 5). Interstitial treatment (in the hands of experienced radiotherapists) yields good results for selected cancers. The method should be more generally accessible in Sweden. Intraoperative radiotherapy should be targeted for further study and development.

Effect of time, dose and fractionation on local control of nasopharyngeal carcinoma

To study the effect of radiation factors on local control of nasopharyngeal carcinoma, 1008 patients with similarly staged T1N03M0 disease (Ho's classification) were retrospectively analyzed. All patients were treated by megavoltage irradiation alone using the same technique. Four different fractionation schedules had been used sequentially during 1976-1985: with total dose ranging from 45.6 to 60 Gy and fractional dose from 2.5 to 4.2 Gy. The median overall time was 39 days (range = 38-75 days). Both for the whole series and 763 patients with nodal control, total dose was the most important radiation factor. The hazard of local failure decreased by 9% per additional Gy (p < 0.01). Biological equivalents expressed in terms of Biologically Effective Dose or Nominal Standard Dose also showed strong correlation. Fractional dose had no significant impact. The effect of overall treatment time was insignificant for the whole series, but almost reached statistical significance for those with nodal control (p = 0.06). Further study is required for elucidation, as 85% of patients completed treatment within a very narrow range (38-42 days), and the possible hazard is clinically too significant to be ignored.

Undifferentiated nasopharyngeal cancer (UCNT): current diagnostic and therapeutic aspects

Undifferentiated carcinoma of the nasopharynx (UCNT) is a particular head and neck epidermoid lineage tumor related to the Epstein Barr Virus (EBV). It has geographically selective endemic epidemiologic features, without relation to external carcinogens. Its systemic agressiveness is the source of most disease-related demises, because radiotherapy achieves excellent local control and a significant percentage of cure in patients with exclusive locoregional disease. Difference in the staying systems currently in use, the recent changes in imaging and radiotherapy technology, and the lack of distinction between UCNT and squamous cell carcinoma (SCC) of the nasopharynx in Western literature reports make for some difficulty in therapeutic results evaluation when analyzing available literature. Its chemosensitivity is a relatively recent acknowledged fact, and its use in metastatic patients results in a high percentage of objective responses, many of long duration. Neoadjuvant cisplatin-based chemotherapy seems to be of benefit, but outstanding controversies in this regard will be soon answered through ongoing phase III trials. After a review of the current literature of all the above-mentioned aspects of this fascinating nosologic entity, our own experience, both in metastatic and locoregional disease patients is analyzed.

Afterloading radiotherapy for local persistence of nasopharyngeal carcinoma

71 patients suffering from local persistence of nasopharyngeal carcinoma after primary external radiotherapy were treated by afterloading intracavitary 192Ir. 66 (93.0%) had a complete response as evidenced by fibreoptic nasopharyngoscope examination and biopsy 4 weeks after the treatment. Significant prognosticators were studied by both monovariate and multivariate analysis. The early overall clinical stage at first presentation predicted a favourable survival. Local tumour control was adversely affected by advanced T-stage at first presentation, and by using a single 192Ir source, unilaterally applied to treat only one side of the nasopharynx. The intracavitary treatment was tolerated well and treatment complications were confined to the nasopharynx: chronic radiation ulceration (five patients) and diffuse telangiectasia (three patients).

Nasopharyngeal carcinoma: local control by megavoltage irradiation

This is a retrospective analysis of the long-term local control in 4128 patients with non-disseminated nasopharyngeal carcinoma treated solely by megavoltage irradiation during the years 1976-1985. The T-stage distribution according to Ho's classification was T1 37%, T2 14% and T3 49%. Different fractionation schedules had been employed at different periods, and the median dose to the primary target was equivalent to 65 Gy by time dose fractionation calculation. In 8% (344) of patients the tumour failed to regress completely after the basic course, but 89% (148/167) of those suitable for salvage with additional irradiation eventually attained complete local remission. The cumulative incidence of local failure was 24% (5% persistence, 19% recurrence). The 10-year actuarial local failure-free survival was 67%. While patients with T2 and T3a tumours achieved local control comparable to T1, those with T3c-d had the poorest control (with highest incidence of persistence and advanced recurrence). T-stage adjusted analyses suggested a significant trend of dose-response: the odds ratios for local failure were 1.16 and 1.86, respectively, when patients given 60-63 Gy and 55-59 Gy were compared with those given 64 Gy or above (p value = 0.0018). Patients treated during 1981-1985 achieved higher local failure-free survival than those treated during 1976-1980 (75% versus 70% at 5 years, p value = 0.0013). The possible attributes are studied, and ways for future optimization of treatment discussed.

Results of chemotherapy plus external reirradiation in the treatment of locally advanced recurrences of nasopharyngeal carcinoma

Between 1982 and 1991, 16 patients with recurrent cancer of the nasopharynx were treated with chemotherapy (CT) and radiotherapy (RT). All patients had received prior RT (45-69, 30 Gy). According to rTNM there were three rT2, one rT3 and 12 rT4. 5 patients were N1. Reirradiation (12-46 Gy, mean: 28) started 3-4 weeks after CT (2-6 cycles of different combinations), but 2 cases involved concomitant therapy. Out of 16 patients 7 had complete response (CR) (43.7%), 7 partial response and 2 no response. Statistically significant prognostic factors for obtaining CR were time of relapse and response to initial CT. Median duration of CR was 22+ months (9-64+). Failures at primary site occurred in 3 patients, 2/2 of those receiving CT without platinum compounds and 1/5 of other ones, with statistically significant difference in local recurrence free-survival between the two groups. Two- and 3-year actuarial overall survival were 28% and 10%. Rates of disease-free survival were 17% and 8%, respectively. The acute toxicity was generally mild. No central nervous system damage or radiation-induced myelitis were observed in survivors.

Carcinoma of the nasopharynx: factors affecting prognosis

This is a retrospective analysis of 143 patients with histologically confirmed epidermoid carcinoma of the nasopharynx treated with definitive irradiation. Patients were treated with a combination of Cobalt-60, 4 to 6 MV X rays, and 18 to 25 MV X rays to the primary tumor and the upper necks, excluding the spinal cord at 4000 to 4500 cGy to total doses of 6000 to 7000 cGy. At 10 years the actuarial primary tumor failure rate was 15% in T1, 25% in T2, 33% in T3, and 60% in T4 lesions. The corresponding failure rate in the neck was 18% for N0, 14% for N1, and 33% for N2 and N3 lymphadenopathy. The incidence of distant metastasis was related to the stage of the cervical lymphadenopathy: 16% in patients with N0-N1 nodes compared with 40% in the N2-3 node group. The actuarial 10-year disease-free survival rate was 55% to 60% for T1-3N0-1 tumors, 45% for T1-3N2-3 tumors, 35% for T4N0-1, and 20% for T4N2-3 lesions. The overall 10-year survival rate was about 40% for patients with T1-2N0-1 tumors, 30% for those with T3 any N stage tumors, and only 10% for the patients with T4 lesions. Multivariate analysis showed that tumor stage and histological type, cranial nerve involvement, patient age, and doses of irradiation to the nasopharynx were significant prognostic factors for local/regional tumor control. Increasing doses of irradiation resulted in nasopharynx tumor control in 80% of the patients receiving 6600 to 7000 cGy and 100% of those receiving over 7000 cGy in the T1, T2, and T3 tumors. However, the tumor control rate did not rise above 55% even for doses over 7000 cGy in the T4 lesions. Local tumor control was higher in patients who had simulation (55/78 = 71%) compared with those on whom simulation was not performed (34/61 = 56%) (p = 0.10). Moreover, patients with more than 75% of the reviewed films judged as adequate had 69% primary tumor control (66/96) compared with 53% (23/43) for those with fewer than 75% adequate portal films (p = 0.07).

Management of local residual primary lesion of nasopharyngeal carcinoma: II. Results of prospective randomized trial on booster dose

Although the question of booster dose for residual primary lesion arises in only 5% of nasopharyngeal carcinoma patients receiving radiotherapy, it poses a difficult problem for clinicians and should be followed. Hence, to test the validity of booster dose for residual primary lesion of nasopharyngeal carcinoma, a prospective randomized trial has been designed and carried out since January 1980. All patients who had a residual lesion in the nasopharynx at 70 Gy were biopsied. Those pathologically positive for cancer were randomized into two groups: (a) positive radiation group (PRG): patients were given further irradiation to a total dose of 90 Gy by the cone-down and assault technique, and (b) positive observation group (POG): patients were given no more irradiation but were followed periodically together with those who were pathology negative (NOG). A total of 78 patients were entered. The validity of booster dose was shown by the 5-year survival rates of the PRG, POG and NOG groups: 75% (3/4), 33% (1/3), and 58% (14/24), respectively. The total local recurrence rates of these groups were 6% (1/16), 36% (5/14), and 4% (2/48), respectively. The authors believe that booster dose for pathology positive residual lesion in the nasopharynx is necessary. The four factors leading to the development of a local recurrence are: (a) residual primary lesion proved positive by pathology but left unboosted, (b) well differentiated squamous cell carcinoma in the original primary lesion, (c) mild radio-response in the cancer parenchyma, and (d) mild radio-response in the interstitial tissue.