Head and neck radiotherapy quality assurance conference for dedicated review of delineated targets and organs at risk: results of a prospective study.

Purpose: Head and neck (HN) radiotherapy (RT) is complex, involving multiple target and organ at risk (OAR) structures delineated by the radiation oncologist. Site-agnostic peer review after RT plan completion is often inadequate for thorough review of these structures. In-depth review of RT contours is critical to maintain high-quality RT and optimal patient outcomes. Materials and Methods: In August 2020, the HN RT Quality Assurance Conference, a weekly teleconference that included at least one radiation oncology HN specialist, was activated at our institution. Targets and OARs were reviewed in detail prior to RT plan creation. A parallel implementation study recorded patient factors and outcomes of these reviews. A major change was any modification to the high-dose planning target volume (PTV) or the prescription dose/fractionation; a minor change was modification to the intermediate-dose PTV, low-dose PTV, or any OAR. We analysed the results of consecutive RT contour review in the first 20 months since its initiation. Results: A total of 208 patients treated by 8 providers were reviewed: 86·5% from the primary tertiary care hospital and 13·5% from regional practices. A major change was recommended in 14·4% and implemented in 25 of 30 cases (83·3%). A minor change was recommended in 17·3% and implemented in 32 of 36 cases (88·9%). A survey of participants found that all (n = 11) strongly agreed or agreed that the conference was useful. Conclusion: Dedicated review of RT targets/OARs with a HN subspecialist is associated with substantial rates of suggested and implemented modifications to the contours.

Retrospective analysis of the impact of HPV status and smoking on mucositis in patients with oropharyngeal squamous cell carcinoma treated with concurrent chemotherapy and radiotherapy.

OBJECTIVES: The standard concurrent radiotherapy and chemotherapy regimens for patients with oropharyngeal cancer are highly toxic. Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) has recently emerged as a distinct biological and clinical entity with improved response to treatment and prognosis. A tailored therapeutic approach is needed to optimize patient care. The aim of our study was to investigate the impact of HPV and smoking status on early toxicities (primarily mucositis) associated with concurrent chemotherapy and radiotherapy in patients with OPSCC. MATERIALS AND METHODS: We retrospectively evaluated 72 consecutive patients with OPSCC and known HPV status treated with concurrent radiotherapy and chemotherapy at our institution. Treatment-related toxicities were stratified by smoking and HPV status and compared using univariate and multivariate logistic regression. RESULTS: HPV-positive patients had a 6.86-fold increase in the risk of having severe, grade 3-4 mucositis. This effect was preserved after adjusting for patient smoking status, nodal stage, radiotherapy technique and radiotherapy maximum dose. Additionally, HPV status had significant effect on the objective weight loss during treatment and at three months after treatment. Consistently, non-smokers had a significant 2.70-fold increase in the risk of developing severe mucositis. CONCLUSION: Risk factors for OPSCC modify the incidence of treatment-related early toxicities, with HPV-positive and non-smoking status correlating with increased risk of high grade mucositis and associated outcomes. Retrospective single-institution studies need to be interpreted cautiously. However, this finding is important to consider when designing therapeutic strategies for HPV-positive patients and merits further investigation in prospective clinical trials.

Serial positron emission tomography scans following radiation therapy of patients with head and neck cancer.

BACKGROUND: A single institution study was undertaken to evaluate the role of positron emission tomography (PET) scans with fluorodeoxyglucose (FDG) prior to radiation and following radiation. METHODS: Forty-five patients with head and neck cancers were evaluated with FDG-PET scans as well as either CT or MRI prior to treatment with definitive radiation (RT). These same scans were obtained following completion of RT at 1 month (36 patients), 4 months (28 patients), 12 months (19 patients), and 24 months (15 patients). Standard uptake values (SUV) normalized for blood glucose and lean body mass were calculated on the initial and 1-month post-treatment PET scans. RESULTS: Fifteen patients are alive without evidence of disease at 24 to 52 months following RT. Initial SUVs were calculated on the primary tumor site and ranged from 2.5 to 28.5. These values did not have any correlation with local control when examined for the entire group, primary site, or T stage. One-month post-RT SUV ranged from 1.8 to 6.24. Of the 36 1-month post-RT PET scans, six were interpreted as positive for residual disease and were confirmed by biopsy. Four of the five scans, which were interpreted as equivocal, were positive on biopsy. Seven of the 25 scans, which were interpreted as negative for tumor, were positive on biopsy. Four-month scans were more accurate for disease with disease noted in 0 of 18 negative scans, 6 of 7 positive scans, and 2 of 3 equivocal scans. CONCLUSIONS: PET is useful for initial imaging of head and neck cancers. SUV does not appear to be useful for predicting outcome following treatment with RT. One-month post-RT scans were inaccurate for predicting the presence of cancer. Four-month post-RT scans were a better predictor for the presence of cancer.

Quantitative analysis from CT is prognostic for local control of supraglottic carcinoma.

BACKGROUND: The purpose of this study was to determine whether pretreatment imaging with CT was prognostic for control of the primary site in patients with squamous cell carcinoma of the supraglottic larynx. METHODS: Pretreatment CT studies were obtained on 28 patients treated definitively with radiation therapy for supraglottic larynx cancer between 1991 and 1997. Follow-up ranged from 20-58 months. RESULTS: Local control was achieved in 61% of patients. Tumor volumes ranged from 0-68.6 cm(3), with a median of 3.1 cm(3). Local control rates for tumors with volumes greater than or less than 8 cm(3) were 20% and 70%, respectively (p =.0077). Mean tumor volumes for patients with and without recurrences were 10 cm(3) and 3.4 cm(3), respectively. CONCLUSIONS: This study demonstrates that quantitative analysis from CT imaging is prognostic for control of the primary site when radiation therapy is given for treatment of supraglottic cancer.

Tailoring radiation to the extent of disease for uterine-confined endometrial cancer.

More than 50 years ago, endometrial cancer was found to be sensitive to radiation, and adjuvant radiation was observed to decrease the incidence of pelvic recurrences. Over the last 2 decades, substantial progress has been made in the understanding of prognostic factors for survival and patterns of disease recurrence for patients with endometrial cancer. Few randomized trials have been done because of the relatively few patients who are at risk of recurrence and the strong bias of many oncologists toward the use of adjuvant radiation. Principles guiding treatment recommendations are based predominately on retrospective publications containing variance in pathological evaluation, surgical evaluation, and patient selection. Preliminary analysis of a randomized Gynecologic Oncology Group trial is reviewed. Optimal therapy for many patients remains to be better defined.

FDG PET evaluation of head and neck cancer: value of imaging the thorax.

BACKGROUND: Patients with primary tumors of the head and neck have been reported to have a high rate of synchronous primary tumors of the upper aerodigestive tract. This study was performed to determine whether inclusion of the thorax in the scan volume would be diagnostically useful for positron emission tomography (PET) with [F-18] fluorodeoxy-D-glucose (FDG) in patients with primary tumors of the head and neck. METHODS: FDG PET scans from the midcranium to the diaphragm were obtained on 56 patients with a variety of head and neck tumors on initial examination before definitive therapy. PET findings in the chest were correlated with results of all other imaging studies, biopsy results, and clinical follow-up. RESULTS: In nine studies (16%), areas of increased FDG uptake in the chest were seen and were judged to be tumors. Six of these probably were false-positive results, although one of these six may have been unconfirmed true positives. Of the three confirmed true-positive studies, two were obvious from other routine studies. In only one case did the PET study reveal a significant lesion not found by means of routine evaluation, resulting in a case-finding yield of 2%. If the unconfirmed possible true-positive results are included, the case-finding yield increases to 4%. CONCLUSIONS: No compelling indication was seen for including the chest in PET studies of patients with head and neck cancer.

Occult primary tumors of the head and neck: lack of benefit from positron emission tomography imaging with 2-[F-18]fluoro-2-deoxy-D-glucose.

BACKGROUND: Patients who present with squamous cell carcinoma metastatic to cervical lymph nodes and no clinically apparent primary site present a therapeutic dilemma. Positron emission tomography imaging with 2-[F-18]fluoro-2-deoxy-D-glucose (FDG-PET) has been shown to be useful for the examination of known primary tumors. This study was undertaken to determine whether FDG-PET imaging improves detection of occult primary tumors in patients with metastatic squamous cell carcinoma in the lymph nodes of the head and neck. METHODS: Thirteen patients with pathology proven cervical lymph node metastases from clinically occult primary squamous cell carcinomas were evaluated prospectively with FDG-PET, in addition to standard clinical and radiographic techniques, as part of their pretreatment diagnostic evaluation. Direct panendoscopy and biopsy were performed on all patients in an attempt to detect primary tumor sites and to characterize them histologically. RESULTS: A primary squamous cell carcinoma was confirmed after panendoscopy and biopsy in 3 of the 13 patients. The site of the primary tumor was correctly identified with FDG-PET in only one of these three patients. The FDG-PET study suggested a primary tumor location where no tumor was found in 6 of 13 patients; for 5 other of the 13 patients, the FDG-PET results were negative and no primary was found. No primary tumor locations were identified by computed tomography, magnetic resonance imaging, or direct panendoscopy. FDG-PET imaging correctly detected the location of the primary tumor in 1 patient (8%) and provided apparent false-positive results for 6 (46%) of the 13 patients. CONCLUSIONS: FDG-PET imaging did not significantly improve detection of unknown primary squamous cell carcinomas in patients with metastases to lymph nodes of the neck. A high percentage of results were apparent false-positive.

Stereotactic Irradiation: potential new treatment method for brain metastases resulting from ovarian cancer.

Stereotactic irradiation (radiosurgery) is a method of precisely focusing well-defined beams of radiation at small intracranial targets. The technique has been applied to the treatment of brain lesions that are benign (e.g., arteriovenous malformations, meningiomas, pituitary adenomas) and malignant (e.g., gliomas, metastases). This paper introduces preliminary data suggesting the possible value of radiosurgery in the management of ovarian cancer metastatic to the brain. Among 32 women with ovarian cancer metastatic to the brain treated with whole brain irradiation, nine (29%) experienced a complete radiographic response, compared with two of the five patients (40%) treated with radiosurgery. The 2-year survival rate was 60% among those treated with radiosurgery and 15% among those who received whole brain irradiation without radiosurgical boost. Stereotactic irradiation may be of clinical benefit to select patients with brain metastases resulting from ovarian cancer. A prospective randomized trial has been implemented by the Radiation Therapy Oncology Group (RTOG 95-08) to determine whether such observations are reproducible on a national scale.

Is there a role for a brachytherapy vaginal cuff boost in the adjuvant management of patients with uterine-confined endometrial cancer?

PURPOSE/OBJECTIVE: Many patients who have uterine-confined endometrial cancer with prognostic factors predictive of recurrence are treated with adjuvant pelvic radiation. The addition of a brachytherapy vaginal cuff boost is controversial. MATERIALS AND METHODS: Between 1983 and 1993, 270 patients received adjuvant postoperative pelvic irradiation following hysterectomy for Stage I or II endometrial cancer. Group A includes 173 patients who received external beam irradiation alone (EBRT), while group B includes 97 patients who received EBRT with a vaginal brachytherapy application. The median dose of EBRT was 45 Gy. Vaginal brachytherapy consisted of a low dose rate ovoid or cylinder in 41 patients, a high dose rate cylinder in 54 patients, and a radioactive gold seed implant in two patients. The median follow-up time was 64 months. The two groups were compared in terms of age, histologic grade, favorable versus unfavorable histology, capillary space invasion, depth of myometrial invasion, and pathologic stage. RESULTS: Chi-square analysis revealed that the only difference between the two groups was the presence of more Stage II patients in group B (38% versus 14%). No difference was detected for 5 year pelvic control and disease-free survival rates between groups A and B. CONCLUSION: There is no suggestion that the addition of a vaginal cuff brachytherapy boost to pelvic radiation is beneficial for pelvic control or disease-free survival for patients with Stage I or II endometrial cancer. Prospective randomized trials designed to study external irradiation alone versus external beam treatment plus vaginal brachytherapy are unlikely to show a positive result. Because EBRT provides excellent pelvic control, protocol development for uterine-confined corpus cancer should focus on identifying patients at risk for recurrence as well as other means of augmenting EBRT (e.g. addition of chemotherapy) in order to improve disease free survival in those subgroups.

Interstitial radiation for recurrent cervix or endometrial cancer in the suburethral region.

Recurrent tumors in the suburethral area are uncommon, but potentially morbid lesions. Brachytherapy, with or without external beam irradiation, was used to treat 10 consecutive women with lesions ranging from 1-6 cm in the suburethral area. All women achieved local control, with one woman developing a serious complication. Four of the 10 women remain alive without evidence of disease. A high rate of distant metastasis in those women who have recurred despite previous adjuvant pelvic radiation following hysterectomy for endometrial cancer should prompt the investigation of effective systemic chemotherapeutic agents.

Laryngeal radionecrosis versus recurrent cancer: a clinical approach.

A group of 38 patients was studied by positron emission tomography utilizing fluorine18-labeled deoxyglucose (FDG-PET) scanning to examine the ability to differentiate postirradiation laryngeal recurrent cancer from radionecrosis. The resulting 79% correct diagnosis showed the technique to be far superior to conventional computed tomography scanning (61%) and clinical examination (43%). An algorithmic approach to evaluating and treating patients with radionecrosis and/or recurrent cancer by utilizing FDG-PET scanning is presented.

Adenocarcinoma of the fallopian tube: results of a multi-institutional retrospective analysis of 72 patients.

PURPOSE/OBJECTIVE: To determine the prognostic factors for predicting outcome of patients with adenocarcinoma of the fallopian tube and to evaluate the impact of treatment modalities in managing this uncommon disease. MATERIALS AND METHODS: A retrospective analysis of the tumor registries from 6 major medical centers from January 1, 1960 up to March 31, 1995 yielded 72 patients with primary adenocarcinoma of the fallopian tube. The Dodson modification of the FIGO surgical staging as it applies to carcinoma of the fallopian tube was utilized. Endpoints for outcome included overall and disease-free survival. Univariate analysis of host, tumor, and treatment factors was performed to determine prognostic significance, and patterns of failure were reviewed. RESULTS: The median age of the study cohort was 61 years (range 30-79 years). Stage distribution was 24 (33%) Stage I; 20 (28%) Stage II; 24 (33%) Stage III; and 4 (6%) Stage IV. Adjuvant chemotherapy was administered to 54 (75%) patients, and postoperative radiotherapy was employed in 22 (31%). In the latter treatment group, 14 (64%) had whole pelvic external beam irradiation, 5 (23%) whole abdominal radiotherapy, 2 (9%) P-32 instillation, and 1 (4%) vaginal brachytherapy alone. Chemotherapy was used in 67% of Stage I and in 79% of Stages II/III/IV disease (not significant); radiotherapy was more commonly employed in Stage I than in Stages II/III/IV (46% vs. 23%, p = 0.05). The 5-, 8-, 15-year overall and disease-free survival for the study patients were 44.7%, 23.8%, 18.8% and 27.3%, 17%, 14%, respectively. Significant prognostic factors of overall survival included Stage I vs. II/III/IV (p = 0.04) and age < or = 60 years vs. > 60 years at diagnosis (p = 0.03). Only Stage I vs. II/III/IV (p = 0.05) was predictive of disease-free survival. Patterns of failure included 18% pelvic, 36% upper abdominal, and 19% distant. For all patients, upper abdominal failures were more frequently found in Stages II/III/IV (29%) than in Stage I (7%) (p = 0.03). Relapses solely outside of what would be included in standard whole abdominal radiotherapy portals occurred for only 15% of patients (6 of 40) with failures. Furthermore, patients having any recurrence, including the upper abdomen, were more likely (p = 0.001) to die (45%) than those without any type of relapse (18%). CONCLUSION: This retrospective, multi-institutional study demonstrated the importance of FIGO stage in predicting the overall and disease-free survival of patients with carcinoma of the fallopian tube. Future investigations should consider exploring whole abdominal irradiation as adjunctive therapy, particularly in Stage II and higher.

FDG PET in head and neck cancer.

In our extensive experience with FDG PET imaging in head and neck cancer, we have found the technique to be of high accuracy but of limited usefulness. This seeming paradox arises from several causes. Competing techniques such as CT, MR imaging, and even clinical examination already have good accuracy. In addition, high-resolution studies such as CT and MR imaging provide information required for treatment planning that is unavailable from FDG PET images. The high cost of FDG PET militates against its use in this setting, in which only a small marginal gain can be expected. In the special problem areas in which FDG PET might be expected to offer unique advantages, such as screening for second primary lesions, searching for unknown primary lesions, or differentiating benign salivary rumors from malignant lesions, the results of FDG PET have been disappointedly poor. Of these special problem areas, only the question of accuracy in finding occult primary lesions appears unresolved and in need of further study. The single application in which FDG PET appears to be advantageous is the posttherapy setting. In this setting, the technique is definitely superior to alternative methods of determining tumor recurrence and differentiating posttherapy sequelae such as radiation necrosis from tumor recurrence. We believe that considerable opportunity remains for further research on the use of FDG PET in head and neck cancer. Other agents such as 11C-methionine for example, might improve the diagnostic accuracy of FDG PET in some of the problem areas that we have identified, such as the early postirradiation period. We currently have such a study under way. Also, because FDG PET offers a unique way to measure tumor metabolism, further investigation of the use of FDG PET tracers to evaluate various biologic parameters such as proliferation rates or tumor hypoxia are needed. Such studies could provide a noninvasive technique to identify which fractionation schemes or combinations of therapy might be useful for individual patients. A final caveat is in order. Although our findings of the usefulness (and lack thereof) of FDG PET in head and neck cancer may be disappointing to many, these results should not be generalized to other applications of FDG PET in oncology. Each tumor type and setting presents its own specific problems, and in some instances FDG PET offers unique advantages over other imaging techniques. A good example is the setting of primary lung cancer, in which FDG PET appears clearly superior to all other methods of pretherapy screening [19-20].

Can positron emission tomography distinguish tumor recurrence from irradiation sequelae in patients treated for larynx cancer?

PURPOSE: Distinguishing persistent or recurrent tumor from post-radiation edema or soft-tissue/cartilage necrosis in patients treated for carcinoma of the larynx can be difficult. Because recurrent tumor is often submucosal, multiple deep biopsies may be necessary before a diagnosis can be established. Positron emission tomography with F-18 fluorodeoxyglucose was studied for its ability to aid in this problem. PATIENTS AND METHODS: FDG PET scans were performed on 31 patients who were suspected of having persistent or recurrent tumor after radiation treatment for carcinoma of the larynx. Patients underwent thorough history and physical examinations, scans with computed tomography (23 patients), and pathological evaluation when indicated. PET scans were interpreted by each of the two radiologists, who were blinded to patient outcome and the other's report. RESULTS: The time between completion of radiation treatment and positron emission tomography examination ranged from 2 to 61 months with a median of 6 months. Fifteen patients had pathological evidence of tumor in the larynx, while 16 have remained without evidence of disease. The overall sensitivity and specificity of the positron emission tomography interpretations were 80% and 81%, respectively. The sensitivity and specificity of the computed tomography scan interpretations were 58% and 100%, respectively. Of the 23 patients with computed tomography scans, eight patients acquired useful information from the positron emission tomography, three patients had incorrect positron emission tomography interpretations and correct computed tomography interpretations, and one patient had positive tumor despite a negative positron emission tomography and computed tomography. DISCUSSION: Positron emission tomography is useful in distinguishing benign from malignant changes in the larynx after radiation treatment. This noninvasive technique can supplement information provided by computed tomography scans. It is reasonable to delay biopsy, which could traumatize radiation-damaged tissues and precipitate necrosis, for those patients with negative positron emission tomography scans who have clinical signs and symptoms associated with recurrence.

Which prognostic factors influence the outcome of patients with surgically staged endometrial cancer treated with adjuvant radiation?

PURPOSE: Despite the fact that retrospective reviews have documented pelvic failure rates ranging from 15-20% in patients with high-risk uterine-confined endometrial cancer who have received no or "inadequate" RT, the role of RT has been questioned. We sought to analyze pelvic control and disease-free survival for a large data base of women with corpus cancers managed with initial surgery followed by adjuvant irradiation. METHODS AND MATERIALS: Between 1983 and 1993, 294 patients received adjuvant postoperative RT from one of three academic radiation practices. RT consisted of vaginal brachytherapy alone in 28 patients, pelvic RT in 173 patients, pelvic RT with vaginal brachytherapy in 97 patients, and whole abdominal RT in 2 patients. Lymph nodes were evaluated in 49%. The median number of pelvic and periaortic LN in the pathology specimen were 6 and 4, respectively. Median follow up was 63 months. RESULTS: 5-year disease-free survival (DFS) rate and pelvic control rates were 86 and 95%, respectively. Patient-related, treatment-related, and tumor-related characteristics were assessed for the effect on time to relapse. Unfavorable histology, older age, and capillary space invasion were univariately associated with decreased DFS and pelvic control. Pathologic Stage II patients had significantly worse DFS than Stage I patients. Multivariate analysis revealed that age, capillary space invasion, and histology were jointly predictive of disease free survival. CONCLUSION: The excellent pelvic control and disease-free survival of patients with uterine-confined disease in this series suggest that adjuvant RT should continue for patients with high risk disease. This analysis of a large group of postoperatively treated patients will provide a basis for determining alternative treatment strategies for patients who have an increased risk of disease recurrence despite RT.

The relationship of local and distant failure from endometrial cancer: defining a clinical paradigm.

PURPOSE: Recently, statistical methods have been developed to rigorously assess the relationship between local and distant failures. Such methodology has successfully been applied to a variety of tumors including those arising in the prostate, breast, and cervix. To date, no published data are available to generate a hypothesis to characterize the relationship between local and distant failure for endometrial cancer. The present analysis was undertaken to determine the effect of locoregional control on subsequent metastatic dissemination among women with pathologically staged endometrial cancer treated by hysterectomy followed by adjuvant radiotherapy. METHODS: The series consisted of 394 patients with FIGO stages I-III endometrial cancer who were surgically staged prior to irradiation [median external beam dose 45 Gy +/- brachytherapy (median vaginal surface dose, 30 Gy)]. The duration of follow-up ranged from 2 to 151 months, with a median of 62 months. Multiple factors were evaluated to determine the associations with distant relapse including FIGO pathological stage, grade, histopathologic subtype (adeno vs papillary/papillary-serous/clear cell), depth of myometrial penetration, age, and local disease status. Time-dependent survival models were generated to assess the influence of local failure on distant metastases. RESULTS: For the entire series, the 5-year actuarial rates of local and distant failures were 9 and 20%, respectively. Women who failed locally had nearly a fourfold risk of failing distantly compared to those who remained locally controlled (P = 0.02). Moreover, the earlier a local failure developed (e.g., within 1 year vs within 3 years), the more likely it was to be associated with distant metastases (P < 0. 05). The univariate correlations of other factors with the 5-year rate of freedom from distant relapse also disclosed significant associations for grade, histology (adenoca vs papillary/papillary-serous/clear cell), and FIGO path stage. In multivariate analysis, only local control, low grade (grade 1 and 2), and early pathological stage were independently related to the likelihood of achieving freedom from distant relapse. CONCLUSIONS: Distant dissemination of endometrial cancer may develop secondary to local failure. Optimization of local control is therefore necessary if long-term cure is to be achieved. The limits of the current database cannot establish whether local failure is a cause of distant spread or a high-risk marker for metastases; however, ongoing national cooperative trials may resolve this controversy.

Definitive radiotherapy for early glottic carcinoma: prognostic factors and implications for treatment.

PURPOSE: Treatment and disease-related factors were analyzed for their influence on the outcome of patients treated definitively with irradiation (RT) for early glottic carcinoma. METHODS AND MATERIALS: One hundred two patients with stage T1 or T2 glottic carcinomas were treated definitively with RT from December 1983 through September 1993. Median follow-up time was 63 months. Factors analyzed for each patient included age, sex, stage, anterior commissure involvement, surgical alternative, histologic differentiation, field size, total dose, fraction size, and total treatment time. Survival analysis methods were employed to assess the effects of these factors on local control and complication rates. RESULTS: The 5-year local control rates by stage were as follows: T1a, 92%; T1b, 80%; T2a, 94%; and T2b, 23%. By univariate analysis, factors found to have a significant impact on local control were stage, surgical alternative, fraction size, anterior commissure involvement, and overall treatment time. By multivariate analysis, stage, field size, and fraction size were the only significant factors that independently influenced local control. CONCLUSION: The inferior control rate for stage T2b lesions has implications for treatment. Our study supports the conclusion of reports in the literature showing that low fraction size negatively influences outcome in patients with early glottic cancer.

Definitive radiotherapy for early glottic carcinoma: prognostic factors and implications for treatment.

PURPOSE: Treatment and disease-related factors were analyzed for their influence on the outcome of patients treated definitively with irradiation (RT) for early glottic carcinoma. METHODS AND MATERIALS: One hundred two patients with stage T1 or T2 glottic carcinomas were treated definitively with RT from December 1983 through September 1993. Median follow-up time was 63 months. Factors analyzed for each patient included age, sex, stage, anterior commissure involvement, surgical alternative, histologic differentiation, field size, total dose, fraction size, and total treatment time. Survival analysis methods were employed to assess the effects of these factors on local control and complication rates. RESULTS: The 5-year local control rates by stage were as follows: T1a, 92%; T1b, 80%; T2a, 94%; and T2b, 23%. By univariate analysis, factors found to have a significant impact on local control were stage, surgical alternative, fraction size, anterior commissure involvement, and overall treatment time. By multivariate analysis, stage, field size, and fraction size were the only significant factors that independently influenced local control. CONCLUSIONS: The inferior control rate for stage T2b lesions has implications for treatment. Our study supports the conclusions of reports in the literature showing that low fraction size negatively influences outcome in patients with early glottic cancer.