Randomized trial addressing risk features and time factors of surgery plus radiotherapy in advanced head-and-neck cancer

PURPOSE

A multi-institutional, prospective, randomized trial was undertaken in patients with advanced head-and-neck squamous cell carcinoma to address (1) the validity of using pathologic risk features, established from a previous study, to determine the need for, and dose of, postoperative radiotherapy (PORT); (2) the impact of accelerating PORT using a concomitant boost schedule; and (3) the importance of the overall combined treatment duration on the treatment outcome.

METHODS AND MATERIALS

Of 288 consecutive patients with advanced disease registered preoperatively, 213 fulfilled the trial criteria and went on to receive therapy predicated on a set of pathologic risk features: no PORT for the low-risk group (n = 31); 57.6 Gy during 6.5 weeks for the intermediate-risk group (n = 31); and, by random assignment, 63 Gy during 5 weeks (n = 76) or 7 weeks (n = 75) for the high-risk group. Patients were irradiated with standard techniques appropriate to the site of disease and likely areas of spread. The study end points were locoregional control (LRC), survival, and morbidity.

RESULTS

Patients with low or intermediate risks had significantly higher LRC and survival rates than those with high-risk features (p = 0.003 and p = 0.0001, respectively), despite receiving no PORT or lower dose PORT, respectively. For high-risk patients, a trend toward higher LRC and survival rates was noted when PORT was delivered in 5 rather than 7 weeks. A prolonged interval between surgery and PORT in the 7-week schedule was associated with significantly lower LRC (p = 0.03) and survival (p = 0.01) rates. Consequently, the cumulative duration of combined therapy had a significant impact on the LRC (p = 0.005) and survival (p = 0.03) rates. A 2-week reduction in the PORT duration by using the concomitant boost technique did not increase the late treatment toxicity.

CONCLUSIONS

This Phase III trial established the power of risk assessment using pathologic features in determining the need for, and dose of, PORT in patients with advanced head-and-neck squamous cell cancer in a prospective, multi-institutional setting. It also revealed the impact of the overall treatment time in the combination of surgery and PORT on the outcome in high-risk patients and showed that PORT acceleration without a reduction in dose by a concomitant boost regimen did not increase the late complication rate. These findings emphasize the importance of coordinated interdisciplinary care in the delivery of combined surgery and RT.

Esthesioneuroblastoma: prognosis and management

Forty-nine patients with esthesioneuroblastoma were treated at the Mayo Clinic between 1951 and 1990. Their clinical manifestations and treatment results were reviewed to identify possible prognostic factors. The 5-year survival rate for all patients was 69%. Tumor progression occurred in 25 patients (51%; no local control in 6 and local recurrence in 19). Metastasis was found in 15 patients (31%; regional in 10 and distant in 9). Nineteen patients died directly from metastatic or intracranial tumor extension. The pathological grade of the tumor was the most significant prognostic factor identified. The 5-year survival rate was 80% for the low-grade tumors and 40% for the high-grade tumors (P = 0.0001). Surgical treatment alone is effective for low-grade tumors if tumor-free margins can be obtained. Radiation is used for low-grade tumors when margins are close, for residual or recurrent disease, and for all high-grade cancers. The poor prognosis associated with high-grade tumors may also mandate the addition of chemotherapy. Recurrent tumor and regional metastasis should be treated aggressively because this approach has been shown to be worthwhile. A craniofacial resection is now the surgical procedure performed in all cases. Because recurrence can occur after 5 or even 10 years, long-term follow-up is mandatory.

Risk of injury to cranial nerves after gamma knife radiosurgery for skull base meningiomas: experience in 88 patients

OBJECT

In this study the authors sought to determine the neurological risks and potential clinical benefits of gamma knife radiosurgery for skull base meningiomas.

METHODS

A consecutive series of 88 patients harboring skull base meningiomas were treated between 1990 and 1996 by using the Leksell gamma knife in a prospective clinical study that included a strict dose-volume protocol. Forty-nine patients had previously undergone surgery, and six had received external-beam radiotherapy. The median treatment volume was 10 cm3, and the median dose to the tumor margin was 16 Gy. The radiosurgical dosage to the optic nerve, the cavernous sinus, and Meckel's cave was calculated and correlated with clinical outcome. The median patient follow-up time was 35 months (range 12-83 months). Two tumors (2.3%) progressed after radiosurgery; the progression-free 5-year survival rate was 95%. At last follow-up review, 60 (68%) tumors were smaller and 26 (29.5%) remained unchanged. Clinical improvement (in vision, trigeminal pain, or other cranial nerve symptoms) occurred in 15 patients. Functioning optic nerves received a median dose of 10 Gy (range 1-16 Gy), and no treatment-induced visual loss occurred. Among nine patients with new trigeminal neuropathy, six received doses of more than 19 Gy to Meckel's cave.

CONCLUSIONS

Gamma knife radiosurgery appeared to be an effective method to control the growth of most skull base meningiomas in this intermediate-term study. The risk of trigeminal neuropathy seemed to be associated with doses of more than 19 Gy, and the optic apparatus appeared to tolerate doses greater than 10 Gy. Considering the risks to cranial nerves associated with open surgery for comparable tumors, the authors believe that gamma knife radiosurgery is a useful method for the management of properly selected recurrent, residual, or newly diagnosed skull base meningiomas.

Does increased nerve length within the treatment volume improve trigeminal neuralgia radiosurgery? A prospective double-blind, randomized study

PURPOSE

To test the hypothesis that increasing the nerve length within the treatment volume for trigeminal neuralgia radiosurgery would improve pain relief.

METHODS AND MATERIALS

Eighty-seven patients with typical trigeminal neuralgia were randomized to undergo retrogasserian gamma knife radiosurgery (75 Gy maximal dose with 4-mm diameter collimators) using either one (n = 44) or two (n = 43) isocenters. The median follow-up was 26 months (range 1-36).

RESULTS

Pain relief was complete in 57 patients (45 without medication and 12 with low-dose medication), partial in 15, and minimal in another 15 patients. The actuarial rate of obtaining complete pain relief (with or without medication) was 67.7% +/- 5.1%. The pain relief was identical for one- and two-isocenter radiosurgery. Pain relapsed in 30 of 72 responding patients. Facial numbness and mild and severe paresthesias developed in 8, 5, and 1 two-isocenter patients vs. 3, 4, and 0 one-isocenter patients, respectively (p = 0.23). Improved pain relief correlated with younger age (p = 0.025) and fewer prior procedures (p = 0.039) and complications (numbness or paresthesias) correlated with the nerve length irradiated (p = 0.018).

CONCLUSIONS

Increasing the treatment volume to include a longer nerve length for trigeminal neuralgia radiosurgery does not significantly improve pain relief but may increase complications.

Esthesioneuroblastoma: the role of adjuvant radiation therapy

PURPOSE

We describe our experience with adjuvant radiation therapy in patients who underwent operation for esthesioneuroblastoma.

METHODS AND MATERIALS

Between January 1951 and December 1990, 49 patients with esthesioneuroblastoma received their initial treatment at the Mayo Clinic. There were 27 male and 22 female patients; their ages ranged from 3 to 79 years (median, 54 years). The tumors were Kadish Stage A in 4 patients, Stage B in 13, Stage C in 29, and modified Kadish Stage D in three (cervical nodal or distant metastasis). The tumors were graded according to Hyams' classification. Treatment included gross total resection alone in 22 patients and gross total resection and postoperative adjuvant radiation therapy in 16. The patients treated with adjuvant radiation had a greater proportion of advanced-stage and high-grade tumors.

RESULTS

The 5-year actuarial overall survival, disease-free survival, and local control rates were 69.1% + 7.0%, 54.8% + 7.6%, and 65.3% + 7.4%, respectively. The only significant predictor for overall survival, disease-free survival, and local control was Hyams' grade. Local control was improved in patients who received postoperative adjuvant radiation even though this group of patients had more advanced and higher-grade tumors (5-year rate of local control was 85.9% + 9.3%, compared with 72.7% + 9.5% for those who had operation alone, p = 0.26).

CONCLUSION

Adjuvant radiation therapy for esthesioneuroblastoma improves local tumor control, particularly for high-grade and high-stage tumors. We recommend additional treatment with radiation (55.5 Gy) after complete resection of esthesioneuroblastoma.

Stereotactic radiosurgery using the gamma knife for acoustic neuromas

PURPOSE

To assess the efficacy and toxicity of stereotactic radiosurgery using the gamma knife for acoustic neuromas.

METHODS AND MATERIALS

Between January 1990 and January 1993, 36 patients with acoustic neuromas were treated with stereotactic radiosurgery using the gamma knife. The median maximum tumor diameter was 21 mm (range: 6-32 mm). Tumor volumes encompassed within the prescribed isodose line varied from 266 to 8,667 mm3 (median: 3,135 mm3). Tumors < or = 20 mm in maximum diameter received a dose of 20 Gy to the margin, tumors between 21 and 30 mm received 18 Gy, and tumors > 30 mm received 16 Gy. The dose was prescribed to the 50% isodose line in 31 patients and to the 45%, 55%, 60%, 70%, and 80% isodose line in one patient each. The median number of isocenters per tumor was 5 (range: 1-12).

RESULTS

At a median follow-up of 16 months (range: 2.5-36 months), all patients were alive. Thirty-five patients had follow-up imaging studies. Nine tumors (26%) were smaller, and 26 tumors (74%) were unchanged. No tumor had progressed. The 1- and 2-year actuarial incidences of facial neuropathy were 52.2% and 66.5%, respectively. The 1- and 2-year actuarial incidences of trigeminal neuropathy were 33.7% and 58.9%, respectively. The 1- and 2-year actuarial incidence of facial or trigeminal neuropathy (or both) was 60.8% and 81.7%, respectively. Multivariate analysis revealed that the following were associated with the time of onset or worsening of facial weakness or trigeminal neuropathy: (a) patients < age 65 years, (b) dose to the tumor margin, (c) maximum tumor diameter > or = 21 mm, (d) use of the 18 mm collimator, and (e) use of > five isocenters. The 1- and 2-year actuarial rates of preservation of useful hearing (Gardner-Robertson class I or II) were 100% and 41.7% +/- 17.3, respectively.

CONCLUSION

Stereotactic radiosurgery using the gamma knife provides short-term control of acoustic neuromas when a dose of 16 to 20 Gy to the tumor margin is used. Preservation of useful hearing can be accomplished in a significant proportion of patients.

Meningioma radiosurgery: tumor control, outcomes, and complications among 190 consecutive patients

OBJECTIVE

To determine local control (LC) and complication rates for patients with intracranial meningiomas who underwent radiosurgery.

METHODS

One hundred ninety consecutive patients with 206 meningiomas underwent radiosurgery between 1990 and 1998. One hundred forty-seven tumors (77%) involved the cranial base. The median age at the time of radiosurgery was 58 years (range, 20-90 yr). There were 126 female patients (66%). One hundred twelve patients (59%) had undergone one or more previous operations (median, 1; range, 1-5). Twenty-two patients (12%) had either atypical (n = 13) or malignant (n = 9) tumors. The median prescription isodose volume was 8.2 cm(3) (range, 0.5-50.5 cm(3)), and the median tumor margin dose was 16 Gy (range, 12-36 Gy). The median imaging and clinical follow-up periods were 40 and 47 months, respectively.

RESULTS

Overall survival rates for the entire cohort at 5 and 7 years were 82 and 82%, respectively; cause-specific survival rates at 5 and 7 years were 94 and 92%, respectively. The cause-specific survival rates at 5 years for patients with benign, atypical, and malignant tumors were 100, 76, and 0%, respectively (P < 0.0001). The 5-year LC rate was 89%, with 114 tumors (56%) decreasing in size. LC rates were correlated with tumor histological features (P < 0.0001); patients with benign tumors exhibited a 5-year LC rate of 93%, compared with 68 and 0% for patients with atypical or malignant meningiomas, respectively. No correlation was observed between radiation dose and LC rate. Twenty-four patients (13%) experienced treatment-related complications, including cranial nerve deficits (8%), symptomatic parenchymal changes (3%), internal carotid artery stenosis (1%), and symptomatic cyst formation (1%). Only six patients (3%) exhibited decreases in functional status that were directly related to radiosurgery. Tumor volume, tumor margin dose, or previous radiotherapy was not associated with the development of radiation-related complications.

CONCLUSION

Radiosurgery is an effective management strategy for many patients with meningiomas. Patients with atypical or malignant tumors exhibit high recurrence rates despite the use of radiosurgery, and these patients continue to exhibit worse cause-specific survival rates despite aggressive treatment, including surgery, external-beam radiotherapy, and radiosurgery. Further study is needed to determine the tumor control and complication rates 10 years or more after meningioma radiosurgery.

Vestibular schwannoma management. Part II. Failed radiosurgery and the role of delayed microsurgery

OBJECT

The indications, operative findings, and outcomes of vestibular schwannoma microsurgery are controversial when it is performed after stereotactic radiosurgery. To address these issues, the authors reviewed the experience at two academic medical centers.

METHODS

During a 10-year interval, 452 patients with unilateral vestibular schwannomas underwent gamma knife radiosurgery. Thirteen patients (2.9%) underwent delayed microsurgery at a median of 27 months (range 7-72 months) after they had undergone radiosurgery. Six of the 13 patients had undergone one or more microsurgical procedures before they underwent radiosurgery. The indications for surgery were tumor enlargement with stable symptoms in five patients, tumor enlargement with new or increased symptoms in five patients, and increased symptoms without evidence of tumor growth in three patients. Gross-total resection was achieved in seven patients and near-gross-total resection in four patients. The surgery was described as more difficult than that typically performed for schwannoma in eight patients, no different in four patients, and easier in one patient. At the last follow-up evaluation, three patients had normal or near-normal facial function, three patients had moderate facial dysfunction, and seven had facial palsies. Three patients were incapable of caring for themselves, and one patient died of progression of a malignant triton tumor.

CONCLUSIONS

Failed radiosurgery in cases of vestibular schwannoma was rare. No clear relationship was demonstrated between the use of radiosurgery and the subsequent ease or difficulty of delayed microsurgery. Because some patients have temporary enlargement of their tumor after radiosurgery, the need for surgical resection after radiosurgery should be reviewed with the neurosurgeon who performed the radiosurgery and should be delayed until sustained tumor growth is confirmed. A subtotal tumor resection should be considered for patients who require surgical resection of their tumor after vestibular schwannoma radiosurgery.

Randomized trial of a chlorhexidine mouthwash for alleviation of radiation-induced mucositis

PURPOSE

To determine whether a chlorhexidine mouthwash could alleviate radiation-induced oral mucositis.

PATIENTS AND METHODS

Patients scheduled to receive radiation therapy to include greater than one third of the oral cavity mucosa were selected for study. Following stratification, they were randomized in a double-blind manner to receive a chlorhexidine mouthwash or a placebo mouthwash. Both groups were then similarly evaluated for mucositis and mouthwash toxicity.

RESULTS

Twenty-five patients were randomized to receive the chlorhexidine mouthwash, while 27 received the placebo mouthwash. Treatment arms were well balanced. There was a trend for more mucositis and there was substantially more toxicity (eg, mouthwash-induced discomfort, taste alteration, and teeth staining) on the chlorhexidine arm.

CONCLUSION

In contrast to the prestudy hypothesis that a chlorhexidine mouthwash might provide benefit for patients receiving radiation therapy to the oral mucosa, this study provides strong evidence suggesting that a chlorhexidine mouthwash is detrimental in this clinical situation.

Stereotactic radiosurgery for cavernous malformations

OBJECT

The use of stereotactic radiosurgery to treat cerebral cavernous malformations (CMs) is controversial. To evaluate the efficacy and safety of CM radiosurgery, the authors reviewed the experience at the Mayo Clinic during the past 10 years.

METHODS

Seventeen patients underwent radiosurgery for high-surgical-risk CMs in the following sites: thalamus/basal ganglia (four patients), brainstem (12 patients), and corpus callosum (one patient). All patients had experienced at least two documented hemorrhages before undergoing radiosurgery. Stereotactic magnetic resonance (MR) imaging was used for target localization in all cases. The median margin radiation dose was 18 Gy and the median maximum dose was 32 Gy. The median length of follow-up review following radiosurgery was 51 months. The annual hemorrhage rate during the 51 months preceding radiosurgery was 40.1%, compared with 8.8% in the first 2 years following radiosurgery and 2.9% thereafter. In 10 patients (59%) new neurological deficits developed that were associated with regions of increased signal on long-repetition time MR imaging performed a median of 8 months (range 5-16 months) after radiosurgery. Three patients recovered, giving the group a permanent radiation-related morbidity rate of 41%. Compared with 31 patients harboring arteriovenous malformations (AVMs) of sizes and in locations similar to those of the aforementioned CMs, who underwent radiosurgery during the same time period, the patients with CMs were more likely to experience radiation-related complications (any complication, 59% compared with 10%; p < 0.001; permanent complication, 41% compared with 10%; p = 0.02).

CONCLUSIONS

It is impossible to conclude that radiosurgery protects patients with CMs against future hemorrhage risk based on the available data, although it appears that some reduction in the bleeding rate occurs after a latency interval of several years. The risk of radiation-related complications after radiosurgery to treat CMs is greater than that found after radiosurgery in AVMs, even when adjusting for lesion size and location and for radiation dose.

Primary head and neck cancer. Histopathologic predictors of recurrence after neck dissection in patients with lymph node involvement

OBJECTIVE

Retrospectively analyze several histopathologic variables that may predict neck recurrence after neck dissection.

DESIGN

From 1970 through 1980, 284 patients with pathologically confirmed metastatic squamous cell carcinoma underwent neck dissection and received no adjuvant therapy. Kaplan-Meier evaluation estimated a 74% 2-year neck recurrence-free rate. After adjusting for the standard covariates of age, gender, neck stage, and tumor grade, we also controlled for the time-dependent covariates of primary recurrence, occurrence in the side of the neck not operated on, or development of new head and neck primary disease.

SETTING

A large referral-based practice.

RESULTS

The number of lymph nodes involved, invasion of vascular/lymphatic space, invasion of soft tissue, and desmoplastic lymph node pattern adversely affect neck recurrence. A desmoplastic stromal pattern was associated with almost a sevenfold increased risk of neck recurrence. To our knowledge, this finding has not been reported previously.

CONCLUSION

Histopathologic evaluation of metastatically involved cervical nodes can identify patients with head and neck cancer who are at high risk for recurrence.

Combined neck dissection and postoperative radiation therapy in the management of the high-risk neck: a matched-pair analysis

PURPOSE

The purpose of this study was to determine the efficacy of postoperative adjuvant radiation therapy with regard to reducing the rate of recurrence in the neck, cancer-related death, and death from any cause in patients with squamous cell carcinoma of the head and neck region metastatic to neck nodes.

METHODS

This was a retrospective review of patients with pathologically confirmed nodal metastases who underwent neck dissection and postoperative adjuvant radiation therapy for squamous cell carcinoma of the head and neck region. Time to recurrence in the dissected area of the neck, any recurrence in the neck, cancer-related death, and death from any cause were estimated with the Kaplan-Meier method. A matched-pair analysis was performed utilizing a cohort of patients who underwent neck dissection without postoperative radiation therapy. The patients from the two cohorts were matched according to previously reported high-risk features for cancer recurrence and death. Cox hazards models for the matched pairs were used to evaluate the relative risk of subsequent recurrence in the dissected side of the neck, any neck recurrence, cancer-related death, and overall survival.

MATERIALS

The medical records and pathologic slides of 95 consecutive patients with pathologically confirmed nodal metastases from squamous cell carcinoma of the head and neck region who underwent neck dissection and postoperative adjuvant radiation therapy between January 1974 and December 1990 were reviewed. Previously published data from 284 patients with squamous cell carcinoma of the head and neck region treated with neck dissection alone between January 1970 and December 1980 were used for a matched-pair analysis.

RESULTS

The relative risks for recurrence in the dissected side of the neck, any neck recurrence (dissected neck or delayed undissected neck metastasis), cancer-related death, and death from any cause for patients treated with operation alone relative to those treated with operation and postoperative radiation were 5.82, 4.72, 2.21, and 1.67, respectively.

CONCLUSION

This study provides evidence that postoperative adjuvant radiation therapy for the high-risk neck can reduce the rate of recurrence within a dissected neck, delayed metastasis within an undissected neck, cancer-related death, and death from any cause.

Results of combined stereotactic radiosurgery and transarterial embolization for dural arteriovenous fistulas of the transverse and sigmoid sinuses

OBJECT

Most dural arteriovenous fistulas (DAVFs) of the transverse and sigmoid sinuses do not have angiographically demonstrated features associated with intracranial hemorrhage and, therefore, may be treated nonsurgically. The authors report their experience using a staged combination of radiosurgery and transarterial embolization for treating DAVFs involving the transverse and sigmoid sinuses.

METHODS

Between 1991 and 1998, 25 patients with DAVFs of the transverse and/or sigmoid sinuses were treated using stereotactic radiosurgery; 22 of these patients also underwent transarterial embolization. Two patients were lost to follow-up review. Clinical data, angiographic findings, and follow-up records for the remaining 23 patients were collected prospectively. The mean duration of clinical follow up after radiosurgery was 50 months (range 20-99 months). The 18 women and five men included in this series had a mean age of 57 years (range 33-79 years). Twenty-two (96%) of 23 patients presented with pulsatile tinnitus as the primary symptom; two patients had experienced an earlier intracerebral hemorrhage (ICH). Cognard classifications of the DAVFs included the following: I in 12 patients (52%), IIa in seven patients (30%), and III in four patients (17%). After treatment, symptoms resolved (20 patients) or improved significantly (two patients) in 96% of patients. One patient was clinically unchanged. No patient sustained an ICH or irradiation-related complication during the follow-up period. Seventeen patients underwent follow-up angiographic studies at a mean of 21 months after radiosurgery (range 11-38 months). Total or near-total obliteration (> 90%) was seen in 11 patients (65%), and more than a 50% reduction in six patients (35%). Two patients experienced recurrent tinnitus and underwent repeated radiosurgery and embolization at 21 and 38 months, respectively, after the first procedure.

CONCLUSIONS

A staged combination of radiosurgery and transarterial embolization provides excellent symptom relief and a good angiographically verified cure rate for patients harboring low-risk DAVFs of the transverse and sigmoid sinuses. This combined approach is a safe and effective treatment strategy for patients without angiographically determined risk factors for hemorrhage and for elderly patients with significant comorbidities.

Decrease in cranial nerve complications after radiosurgery for acoustic neuromas: a prospective study of dose and volume

PURPOSE

To determine whether tumor control can be maintained, and cranial nerve complications decreased by reducing the radiosurgical dose to acoustic neuromas.

METHODS AND MATERIALS

Forty-two consecutive patients with acoustic neuromas were treated prospectively using an initial standard-dose protocol in which the tumor-margin dose (50% isodose) was 20, 18, and 16 Gy for tumor diameters < or =2 cm, 2.1-3 cm, and 3.1-4 cm, respectively. After analysis of tumor control and complications, the next 40 patients were treated using a reduced-dose protocol in which the tumor-margin dose was 16, 14, and 12 Gy for tumor volumes < or =4.2 cm3, 4.2-14.1 cm3, and > or =14.1 cm3, respectively.

RESULTS

Median follow-up was 2.3 years (range 0.1-6) for 80 of 82 patients. The actuarial incidence (Kaplan-Meier) of facial neuropathy at 2 years was 38% (95% confidence interval [CI], 23-53%) for the standard-dose protocol and 8% (95% CI, 0-17%) for the reduced-dose protocol (p = 0.006). Univariate analysis revealed an association between risk of facial neuropathy and use of CT planning, higher radiosurgical dose, and neurofibromatosis, type 2. Multivariate analysis revealed that the only factor associated with increased risk of post-treatment facial neuropathy was a tumor margin dose > or =18 Gy. The incidence of trigeminal neuropathy at 2 years was 29% (95% CI, 15-43%) for the standard-dose protocol and 15% (95% CI, 3-27%) for the reduced-dose protocol (p = 0.17). Univariate analysis revealed an association between maximal tumor diameter and increased risk of trigeminal neuropathy; multivariate analysis revealed no additional statistically significant associations between tumor and dosimetric and patient characteristics and risk of trigeminal neuropathy. Two tumors in the standard-dose protocol required salvage surgery for progression. To date, no tumor in the reduced-dose protocol has shown progression.

CONCLUSION

Our analysis suggests that a tumor margin dose of > or =18 Gy is the most significant risk factor for facial nerve complications after acoustic neuroma radiosurgery. Patients receiving a minimal tumor dose of < or =16 Gy are at significantly lower risk for permanent facial neuropathy after radiosurgery. Longer follow-up is required before definitive conclusions can be made about the ultimate rate of tumor control using reduced radiosurgical doses.

The rationale and technique of staged-volume arteriovenous malformation radiosurgery

PURPOSE

Stereotactic radiosurgery is an effective management strategy for properly selected arteriovenous malformation (AVM) patients. However, the risk of postradiosurgical radiation-related injury generally limits this procedure to patients with AVMs of an average diameter of 3 cm or less. Radiosurgery of large AVMs in a planned staged fashion was undertaken to limit the radiation exposure to the surrounding normal brain.

METHODS AND MATERIALS

Between April 1997 and December 1999, 10 patients with a median AVM volume of 17.4 cm(3) (range, 7.4-53.3 cm(3)) underwent staged-volume radiosurgery (23 procedures). At the first radiosurgical procedure, the total volume of the AVM is estimated and a dose plan calculated that covers 10 cm(3)-15 cm(3), or one-half the nidus volume if the AVM is critically located (brainstem, thalamus, or basal ganglia). At 6-month intervals thereafter, radiosurgery was repeated to different portions of the AVM with the previous dose plan(s) being re-created utilizing intracranial landmarks to minimize radiation overlap. Radiosurgical procedures were continued until the entire malformation has been irradiated.

RESULTS

The radiation dosimetry of staged-volume AVM radiosurgery was compared to hypothetical single-session procedures for the 10 patients. Staged-volume radiosurgery decreased the 12-Gy volume by an average of 11.1% (range, 4.9-21%) (p < 0.001). The non-AVM 12-Gy volume was reduced by an average of 27.2% (range, 12.5-51.3%) (p < 0.001).

DISCUSSION

Staged-volume radiosurgery of large AVMs results in less radiation exposure to the adjacent brain. Further follow-up is needed to determine whether this technique provides a high rate of AVM obliteration while maintaining an acceptable rate of radiation-related complications.

Cervical nodal metastasis of squamous cell carcinoma of unknown origin: indications for withholding radiation therapy

The records of patients with pathologically confirmed metastatic squamous cell carcinoma involving cervical lymph nodes who were treated at the Mayo Clinic between January 1965 and December 1987 were reviewed. In 117 patients a primary tumor could not be discovered. Of these, 24 patients underwent curative resection of all gross disease by neck dissection or excisional biopsy. All 24 patients presented with unilateral adenopathy. Their median age was 63 years. Eighteen patients were men. Fourteen patients were in clinical stage N1; six, N2a; three, N2b; and one, N3. Six patients had grade 1 or 2 nodal metastases; 14, grade 3; and 4, grade 4. Gross or microscopic evidence of extracapsular tumor extension was noted in eight patients. All patients were followed until death or for a median of 8.5 years (range, 3.3-20.4 years). A squamous cell carcinoma of the upper aerodigestive tract subsequently developed in only one patient (4%) within 5 years of operation. In six patients (25%), a recurrence developed in the dissected neck a median of 3 months (2.4 months-6.6 years) after operation. Five of these patients had extracapsular extension, and four had pathologic Stage N2a or higher neck disease. Both patients with pathologic Stage N1 disease who had recurrences in the dissected neck had extracapsular extension. Delayed, contralateral neck metastases in an undissected neck developed in two patients. The 5-year overall and cause-specific survivals for all 24 patients were 66% and 74%, respectively. Extracapsular extension was a predictor of neck recurrence, control of disease above the clavicles, cause-specific survival, and overall survival. Patients with pathologic Stage N1 neck disease with no extracapsular extension can be managed by surgery alone. Patients with pathologic Stage N2 or higher neck disease or extracapsular extension should be considered for postoperative, adjuvant radiation therapy.

Head and neck synovial cell sarcoma

Our experience with 14 patients treated for synovial cell sarcoma during the past 30 years is described. These tumors were manifested in young people whose ages ranged from 12 to 43 years. The diagnosis of synovial cell sarcoma proved difficult because approximately one third of the patients initially received incorrect pathologic diagnoses. A painless neck mass was the most common presenting symptom. Initial treatment included surgical excision in five patients and surgical excision and radiation therapy in nine. Recurrent or metastatic tumor occurred from 4 months to 62 months later; thus, long-term followup is important. Four of the nine patients who were followed more than 5 years died of their disease. Favorable prognostic findings included early diagnosis and the performance of wide surgical removal.

The role of stereotactic radiosurgery in the treatment of malignant skull base tumors

PURPOSE

To determine the efficacy and toxicity of stereotactic radiosurgery in the treatment of malignant skull base tumors.

METHODS AND MATERIALS

Thirty-two patients with 35 newly diagnosed or recurrent malignant skull base tumors < or = 33.5 cm3 were treated using the Leksell Gamma unit. Tumor histologies included: adenoid cystic carcinoma [12], basal cell carcinoma [1], chondrosarcoma [1], chordoma [8], nasopharyngeal carcinoma [3], osteogenic sarcoma [2], and squamous cell carcinoma [8].

RESULTS

After a median follow-up of 2.3 years, 83% +/- 15% (+/-95% confidence interval) of patients experienced a symptomatic response to treatment. Local control at the skull base was 95 +/- 9% at 2 years and 78 +/- 23% at 3 years. Local-regional control above the clavicles was 75 +/- 15% at 1 year and 51 +/- 20% at 2 years. Overall and cause specific survival were identical, 82 +/- 13% at 1 year, 76 +/- 14% at 2 years, and 72 +/- 16% at 3 years. One patient developed a radiation-induced optic neuropathy 12 months after radiosurgery.

CONCLUSION

Stereotactic radiosurgery using the Leksell Gamma Unit can provide durable tumor control and symptomatic relief with acceptable toxicity in the majority of patients with malignant tumors 4 cm or less in size involving the skull base. Further evaluation of more patients with longer follow-up is warranted.

Planned postradiotherapy neck dissection in patients with advanced head and neck cancer

BACKGROUND

Metastatic neck nodes in patients with squamous cell carcinoma of the head and neck are most commonly managed by surgery, radiotherapy, or combined-modality therapy. For combined-modality cases, the sequencing of surgery and radiotherapy is generally guided by which modality is considered preferable for treatment of the primary tumor. A postradiotherapy neck dissection is often considered for those patients with > N1 disease in which the primary is treated with radiotherapy alone.

METHODS

Between February 1991 and October 1995, 25 patients with node-positive squamous cell carcinoma of the head and neck were treated with planned unilateral (n = 22) or bilateral (n = 3) neck dissection following high-dose radiotherapy. The primary tumor sites included: tongue base (n = 11), tonsil (n = 6), nasopharynx (n = 3), pyriform sinus (n = 2), supraglottic larynx, (n = 1), soft palate (n = 1), and unknown head and neck primary (n = 1). The specific nodal stage breakdown of the 28 individual neck dissections (25 patients) was N1 (n = 1), N2A (n = 5), N2B (n = 15), N3 (n = 7).

RESULTS

Nineteen of the 28 neck dissections (68%) demonstrated no evidence of residual carcinoma. Of the nine positive neck dissections, six revealed malignant cells in a single nodal echelon. The 1- and 2-year rate of neck control in all 25 patients was 100% and 93%, respectively. The 1- and 2-year disease-specific survival for all 25 patients was 83% and 60%, respectively. With a minimum follow-up of 2 years, 64% of the 25 patients remain alive with no evidence of disease or dead of non-cancer causes.

CONCLUSION

In this series of postradiotherapy neck dissections, two thirds of the dissections demonstrated no evidence of residual tumor (19/28, or 68%). However, there was not a direct correlation between pretreatment nodal size (neck staging), radiation dose delivered, and the likelihood of achieving a cancer-free neck dissection. Only one of 28 postradiotherapy neck dissections identified tumor outside of nodal stations II-IV. The predictable pattern of residual disease in pathologically positive cases suggests that a selective neck dissection encompassing levels II-IV may be appropriate in a majority of patients.

Angiosarcomas of the head and neck: clinical and pathologic characteristics

Between 1974 and 1992, 32 patients with pathologically diagnosed angiosarcoma of the head and neck were evaluated at our institution. The primary treatment group consisted of 24 patients who had the initial diagnosis made or confirmed at our institution, and the other 8 patients formed the salvage group. There were 23 men and 9 women. The median age in the primary treatment group was 63 years (range 18 to 91 years). The overall median survival among the primary group patients was 4.8 years, and the 3-year survival was estimated to be 57% (95% confidence interval 39% to 84%). The median follow-up was 2.1 years (range 83 days to 9.7 years). Patients who had tumors less than 7.0 cm in diameter and tumors with invasion only to the subcutaneous tissues had better overall survival and longer time to first adverse event. Diploid DNA content was a significant favorable prognostic factor for time to first adverse event. Mitotic activity was of borderline significance with both end points. Patients who had tumors of less than 1.5 cm were treated successfully with surgery alone. Patients treated with combined surgery and radiotherapy also tended to do better. Because most patients in whom regional recurrences developed had tumors larger than 7.0 cm, we conclude that patients with tumors of this size may benefit from regional neck node dissection at the time of primary excision or from elective neck irradiation.

Limited-stage small-cell lung cancer: patterns of intrathoracic recurrence and the implications for thoracic radiotherapy

PURPOSE

This analysis was performed to determine the most appropriate volume that should be encompassed by thoracic radiation treatments (TRTs) for patients with limited-stage small-cell lung cancer (LSSCLC) who have responded to initial chemotherapy.

PATIENTS AND METHODS

A retrospective review of all patients (N = 67) with LSSCLC who were not entered onto a research protocol and were treated at our institution between the years of 1982 and 1990 was performed. Fifty-nine of 67 patients had adequate information regarding the size of the tumor before the start of chemotherapy (computed tomographic [CT] scan of chest or chest x-ray), the size of the tumor before TRT, and the TRT field size based on a simulation radiography. All 59 patients were treated with cyclophosphamide-based chemotherapy, and TRT was generally delivered concomitantly with chemotherapy following two to three cycles of chemotherapy alone.

RESULTS

Of 59 patients, 28 were treated with TRT field sizes that encompassed postchemotherapy tumor volumes, and 31 patients were treated with TRT field sizes that encompassed prechemotherapy tumor volumes (defined as a volume that included at least a 1.5-cm margin on the prechemotherapy tumor volume). Nineteen patients had an intrathoracic recurrence of disease as the first site of recurrent small-cell carcinoma: 10 of 31 patients treated with TRT fields that encompassed prechemotherapy tumor volumes and nine of 28 patients treated with TRT fields that encompassed postchemotherapy tumor volumes. For the 28 patients treated with TRT fields that encompassed postchemotherapy tumor volumes, the greatest distance that the prechemotherapy tumor volume (without margins) extended beyond the edge of the TRT field was 0.5 to 5.0 cm, with a median of 2.5 cm. All 19 of the intrathoracic recurrences were in-field failures, although two patients (one prechemotherapy volume and one postchemotherapy volume) did have concurrent pleural effusions.

CONCLUSION

These results indicate that the use of TRT fields that encompass postchemotherapy tumor volumes does not increase the risk of marginal failures or intrathoracic failures outside the TRT field.

Base of tongue carcinoma: patterns of failure and predictors of recurrence after surgery alone

Between January 1971 and December 1986, 55 patients with squamous cell carcinoma of the tongue base underwent complete surgical resection with curative intent. No preoperative or postoperative adjuvant therapy was administered. The study group consisted of 41 men and 14 women (median age 61 years). All patients were followed until death (39 patients) or for a median of 9.4 years. Local control at 5 years was 74%. No predictors of local recurrence were discovered. Control in the dissected neck at 5 years was 68%. Control of cancer above the clavicles at 5 years was 48%. Distant metastases developed in 14% of the patients by 5 years. Cause-specific survival at 5 years was 65%. A Cox multivariate regression analysis revealed that pathologic N stage was the only significant independent predictor of recurrence in the dissected neck, recurrence above the clavicles, and cause-specific survival. The 5-year overall survival was 55%. Surgical mortality was 4%.

The impact of surgical adjuvant thoracic radiation therapy for patients with nonsmall cell lung carcinoma with ipsilateral mediastinal lymph node involvement

BACKGROUND

Previous nonsmall cell lung carcinoma studies have shown that patients with ipsilateral mediastinal (N2) lymph node involvement who underwent surgical resection have a greater local recurrence rate than those with less lymph node involvement (N0, N1). Therefore, it was hypothesized that complete surgical clearance of subclinical lymph node disease is difficult in N2 patients and that adjuvant postoperative thoracic radiotherapy (TRT) may be beneficial.

METHODS

A retrospective review was performed to determine the local recurrence and survival rates for patients with N2 disease undergoing complete surgical resection with or without adjuvant TRT. Between 1987 and 1993 at the Mayo Clinic, 224 patients underwent complete resection of N2 nonsmall cell lung carcinoma. More than one mediastinal lymph node station was sampled in 98% of patients; 39% then received adjuvant TRT (median dose, 50.4 grays).

RESULTS

The median follow-up time was 3.5 years for the patients who were alive at the time of the analysis. The surgery alone versus surgery plus TRT groups were well balanced with respect to gender, age, histology, tumor grade, number of mediastinal lymph node stations dissected or involved, and involved N1 lymph node number. There were slightly more patients with right lower lobe lesions (compared with other lobes), patients with multiple lobe involvement, and patients with only one N2 lymph node involved in the surgery alone group. After treatment with surgery alone, the actuarial 4-year local recurrence rate was 60%, compared with 17% for treatment with adjuvant TRT (P < 0.0001). The actuarial 4-year survival rate was 22% for treatment with surgery alone, compared with 43% for treatment with adjuvant TRT (P = 0.005). On multivariate analysis, the addition of TRT (P = 0.0001), absence of superior mediastinal lymph node involvement (P = 0.005), and fewer N1 lymph nodes involved (P = 0.02) were independently associated with improved survival rate.

CONCLUSIONS

This study, which to the authors' knowledge is the largest evaluating adjuvant TRT in N2 nonsmall cell lung carcinoma, suggests that adjuvant TRT may improve local control and survival.

Stereotactic radiosurgery for glomus jugulare tumors: a preliminary report

PURPOSE

This study was conducted to evaluate the toxicity and efficacy of stereotactic radiosurgery treatment of glomus jugulare tumors.

METHODS AND MATERIALS

Between March 1990 and January 1995, nine patients underwent stereotactic radiosurgery with the Leksell Gamma Knife Unit for glomus jugulare tumors. Previous treatment had failed in four patients. The seven female and two male patients had a median age of 67 years.

RESULTS

The median time from stereotactic radiosurgery to the most recent clinical follow-up was 20 months (range 7-65 months). Subjectively, 7 of 9 patients noted a decrease in the intensity of their symptoms. Objectively, 8 of 9 tumors remained stable in size by serial magnetic resonance imaging scans and one was smaller. There was no acute or chronic toxicity.

CONCLUSION

This early experience suggests that stereotactic radiosurgery is a promising treatment for glomus jugulare tumors.

A randomized trial of a nonabsorbable antibiotic lozenge given to alleviate radiation-induced mucositis

BACKGROUND

The objective of this study was to determine whether a nonabsorbable antibiotic lozenge could alleviate radiation-induced oral mucositis.

METHODS

Patients scheduled to receive radiation therapy to more than one-third of the oral cavity mucosa were selected for the study. After stratification, patients were randomized to receive either a nonabsorbable antibiotic lozenge or a placebo. Both groups were then evaluated for mucositis by health care providers and self-report instruments.

RESULTS

Fifty-four patients were randomized to receive the antibiotic lozenge and 58 to receive the placebo. There were no substantial differences or trends in mucositis scores between the two study arms as measured by the health care providers. However, the mean patient-reported mucositis score and the duration of patient-reported Grade 3-4 mucositis were both lower in the patients randomized to the antibiotic lozenge arm (P = 0.02 and 0.007, respectively).

CONCLUSIONS

This prospective, controlled trial provides evidence to suggest that a nonabsorbable antibiotic lozenge can decrease patient-reported radiation-induced oral mucositis to a modest degree. Nonetheless, this evidence does not appear to be compelling enough to recommend this treatment as part of standard practice.