Fractionation and outcomes with palliative radiation therapy.

A dose-response relationship can be established for local control of a variety of malignancies treated with radiation, yet palliation of symptoms oftentimes does not have a clear dose-response relationship. It is important that palliation be achieved with as efficient a fractionation schedule as possible in patients with limited life expectancy and with as few side effects as possible. This article reviews the literature addressing optimal schedules of radiation for palliation based on prognostic factors.

Morbidity after midline mandibulotomy and radiation therapy.

PURPOSE: To assess the morbidity of mandibulotomy in patients treated for neoplasms of the oropharynx and oral cavity, and to determine if postoperative radiation therapy to the mandibulotomy site carries an increased risk of complications. PATIENTS AND METHODS: The medical charts of 30 patients treated between 1992 and 1996 undergoing midline mandibulotomy for tumors of the oral cavity (7 patients) and oropharynx (23 patients) were retrospectively reviewed. Three patients presented with recurrent disease, 1 of whom was previously irradiated. Twenty-five patients received postoperative radiation after mandibulotomy to a median dose of 60 Gy to the primary tumor bed, whereas 5 patients were treated with surgery alone. The patients were separated into those whose mandibulotomy site was within the radiation treatment field (n = 9), and those whose site was shielded (n = 10). Median follow-up was 27.8 months (range 5-81 months). End points included significant pain involving the mandibulotomy site, trismus, malocclusion, wound infection, osteoradionecrosis, and time to oral intake. RESULTS: There were no postoperative deaths. Minor wound infection or breakdown occurred in 4/30 patients (13%). All of these resolved with local care and parenteral antibiotics. More serious complications involving the mandibulotomy occurred in 2 patients (7%). One patient had chronic wound drainage at the mandibular osteotomy site, which healed after plate removal. Another patient developed osteoradionecrosis. No patient developed trismus or malocclusion. With a median follow-up of 27.8 months, 4 patients have recurred locally. The complication rate was 11% for patients whose mandibulotomy site was irradiated, and 30% for those whose site was shielded. CONCLUSION: Mandibulotomy can be safely performed in patients who are likely to require postoperative external radiation.

A phase I/II study of external beam radiation, brachytherapy, and concurrent chemotherapy for patients with localized carcinoma of the esophagus (Radiation Therapy Oncology Group Study 9207): final report.

BACKGROUND: A multiinstitutional, prospective study of the Radiation Therapy Oncology Group (RTOG) was designed to determine the feasibility and toxicity of chemotherapy, external beam radiation, and esophageal brachytherapy (EB) in a potentially curable group of patients with adenocarcinoma or squamous cell carcinoma of the esophagus. A preliminary analysis indicated a 17% 1-year actuarial risk of treatment-related fistulas. A final analysis of this study was considered important to determine the median survival time, local control, and late toxicity associated with this treatment regimen. METHODS: Planned treatment was 50 grays (Gy) of external beam radiation (25 fractions given over 5 weeks) followed 2 weeks later by EB (either high-dose-rate 5 Gy during Weeks 8, 9, and 10, for a total of 15 Gy, or low-dose-rate 20 Gy during Week 8). Chemotherapy was given during Weeks 1, 5, 8, and 11, with cisplatin 75 mg/m(2) and 5-fluorouracil 1000 mg/m(2)/24 hours in a 96-hour infusion. RESULTS: Of the 49 eligible patients, 45 (92%) had squamous histology and 4 (6%) had adenocarcinoma. Forty-seven patients (96%) completed external beam radiation plus at least 2 courses of chemotherapy, whereas 34 patients (69%) were able to complete external beam radiation, EB, and at least 2 courses of chemotherapy. The estimated survival rate at 12 months was 49%, with an estimated median survival of 11 months. Life-threatening toxicity or treatment-related death occurred in 12 (24%) and 5 (10%) cases, respectively. Treatment-related esophageal fistulas occurred in 6 cases (12% overall, 14% of patients starting EB) at 0.5-6.2 months from the first day of brachytherapy, leading to death in 3 cases. CONCLUSIONS: In this study, severe toxicity, including treatment-related fistulas, occurred within 7 months of brachytherapy. Based on the 12% incidence of fistulas, the authors continue to urge caution in employing EB, particularly when used in conjunction with chemotherapy.

Outcome of patients receiving radiation for cancer of the esophagus: results of the 1992-1994 Patterns of Care Study.

PURPOSE: A Patterns of Care Study examined the records of patients with esophageal cancer (EC) treated with radiation in 1992 through 1994 to determine the national practice processes of care and outcomes and to compare the results with those of clinical trials. PATIENTS AND METHODS: A national survey of 63 institutions was conducted using two-stage cluster sampling, and specific information was collected on 400 patients with squamous cell (62%) or adenocarcinoma (37%) of the thoracic esophagus who received radiation therapy (RT) as part of primary or adjuvant treatment. Patients were staged according to a modified 1983 American Joint Committee on Cancer staging system. Fifteen percent of patients had clinical stage (CS) I disease, 40% had CS II disease, and 30% had CS III disease. Twenty-six percent of patients underwent esophagectomy. Seventy-five percent of patients received chemotherapy; 84% of these received concurrent chemotherapy and radiation (CRT). RESULTS: Significant variables for overall survival in multivariate analysis include the use of esophagectomy (risk ratio [RR] = 0.62), the use of chemotherapy (RR = 0.63), Karnofsky performance status (KPS) greater than 80 (RR = 0.61), CS I or II disease (RR = 0.66), and facility type (RR = 0.72). Age, sex, and histology were not significant. Preoperative CRT resulted in a nonsignificantly higher 2-year survival rate compared with definitive CRT alone (63% v 39%; P =.11), whereas 2-year survival by planned treatment rather than treatment given was 47.7% for preoperative CRT and 35.4% for definitive CRT (P =.23). Definitive CRT compared with definitive RT alone resulted in significantly higher 2-year survival (39% v 20.6%; P =.027) and lower 2-year local regional failure (30% v 57.9%; P =. 0031). CONCLUSION: This study confirms the value of CRT in EC treatment. It indicates that the results obtained in practice settings nationwide are similar to those obtained in clinical trials and that KPS and the 1983 clinical staging system are useful prognostic indicators. The suggested value of esophagectomy and superiority of preoperative CRT over CRT alone in this study should be tested in a randomized trial.

Patterns of care in radiation oncology.

OBJECTIVES: To provide an overview of the Patterns of Care Study (PCS) in radiation oncology and to discuss the progress and impact of the PCS on clinical practice. DATA SOURCES: Research studies and review articles. CONCLUSIONS: The PCS has demonstrated tremendous impact on the delivery of radiation oncology services in the United States. The PCS surveys the discipline of radiation oncology to determine quality of care and provide outcome data to enhance the delivery of radiation treatment in diverse settings. NURSING IMPLICATIONS: Radiation oncology nurses occupy a pivotal place in the quest to promote quality clinical care. A knowledge base about the activities of the PCSs and the integration of nursing participation in future studies has the potential to enhance patient care.

Outcomes of patients receiving radiation for carcinoma of the rectum. Results of the 1988-1989 patterns of care study.

BACKGROUND: Clinical trials of surgical adjuvant treatment for patients with rectal carcinoma (RC) indicate that postoperative radiation therapy with concurrent chemotherapy (CRT) is superior to postoperative radiation alone (RT) or surgery alone. Whether preoperative treatment is superior to postoperative treatment is controversial. This Patterns of Care Study (PCS) surveyed patients with RC treated with radiation during the years 1988-1989 to determine the national practice standards and outcomes and to compare these results with those of clinical trials. METHODS: A national survey of 73 institutions was conducted using 2-stage cluster sampling, and specific information on 406 patients with RC who received radiation at 69 facilities was collected. Follow-up information on 215 patients was subsequently collected by mail survey. There were no significant differences between the known prognostic indicators or treatment-related variables for patients for whom follow-up was available compared with the variables for patients for whom follow-up was not available. Follow-up ranged from 0 to 8.44 years with a median of 4 years. One hundred fifty-four patients (71%) received postoperative treatment, either RT (37%) or CRT (34%); and 40 (18%) received preoperative treatment, either RT (15%) or CRT (3%). Ninety-six patients (45%) received chemotherapy, and for 86% of those patients chemotherapy was administered concurrently with radiation. RESULTS: Survival was stage-dependent (85% Stage I, 69% Stage II, and 54% Stage III at 5 years, P = 0.04). Survival was also substage-dependent, and patients with C(1) cancer had significantly higher 5-year survival than those with C(2)/C(3) cancer (89% vs. 48%, P = 0.008). Local failure was similar for Stage II and Stage III patients (10% vs. 11% at 5 years, respectively). In multivariate analyses, only stage and use of chemotherapy were significant to survival (Stage III vs. Stage I and II, relative risk [RR] = 2.52, and chemotherapy vs. no chemotherapy, RR = 0.46). A significantly higher 5-year survival rate was seen with postoperative CRT than with postoperative RT (69% vs. 50%, P = 0. 011). Preoperative radiation resulted in a significantly higher 5-year survival rate than postoperative radiation (85% vs. 50%, P = 0.0006), but not compared with postoperative CRT. Survival and local failure did not differ according to radiation therapy interruption or the interval between surgery and radiation. CONCLUSIONS: Stage is an important prognostic indicator for survival, and among patients with Stage III malignancies survival in the substage C(1) is significantly higher than in the substages C(2) and C(3). As has been demonstrated in randomized trials, adjuvant postoperative CRT is superior to postoperative RT for patients with RC in this national study. These nationwide results of adjuvant treatment are comparable to those reported in randomized trials. The use of CRT was the only treatment-related factor that resulted in a significant reduction in the risk of death.

The evaluation and treatment of patients receiving radiation therapy for carcinoma of the esophagus: results of the 1992-1994 Patterns of Care Study.

BACKGROUND: For the first time, a Patterns of Care Study (PCS) was conducted in 1992-1994 to determine the national practice standards in evaluating and treating patients with esophageal carcinoma and to determine the degree to which clinical trials have been incorporated into national practice. METHODS: A national survey of 61 institutions using 2-stage cluster sampling was conducted, and specific information was collected on 400 patients with squamous cell carcinoma or adenocarcinoma of the thoracic esophagus who received radiation therapy (RT) as part of definitive or adjuvant management of their disease. Patients were staged according to a modified 1983 American Joint Committee on Cancer staging system. Chi-square tests for significant differences between academic and nonacademic institutions for a particular variable were performed. RESULTS: The median age of patients was 66.7 years (range, 26-89 years); 76.5% were male and 23.5% were female. Karnofsky performance status was > or = 80 for 88.3% of patients. Squamous cell carcinoma was diagnosed in 61.5% and adenocarcinoma in 36.8%. Fifteen percent were Clinical Stage (CS) I, 39.5% CS II, and 29.5% CS III. Evaluative procedures included endoscopy (>93%), computed tomography (CT) of the chest (86%), CT of the abdomen (75%), esophagography (68.5%), and endoscopic ultrasound (3.5%). Endoscopic ultrasound and CT of the chest were performed significantly more frequently at academic than nonacademic facilities (6.1% vs. 1.0% and 91.9% vs. 81.3%, respectively). Three-quarters of all patients received chemotherapy and RT and 62.5% received concurrent chemotherapy and RT as part of their treatment. Treatments included chemotherapy plus RT (54.0%), RT alone (20.3%), preoperative chemotherapy + RT (13.3%), postoperative chemotherapy + RT (7.7%), postoperative RT (3.5%), and preoperative RT (1.2%). The chemotherapeutic agents most frequently used were 5-fluorouracil (84%), cisplatin (64%), and mitomycin (9%); academic instututions used cisplatin significantly more often and mitomycin significantly less often than nonacademic institutions. Brachytherapy was used in 8.5% of cases. The median total dose of external beam radiation was 50.4 gray and the median dose per fraction was 1.8 gray. CONCLUSIONS: This study establishes the national benchmarks for the evaluation and treatment of patients with esophageal carcinoma at radiation facilities in the U.S. It also indicates that the majority of patients given RT as a component of treatment for esophageal carcinoma receive chemoradiation rather than RT alone, as supported by clinical trials. Although some differences in the evaluation of esophageal carcinoma were noted between academic and nonacademic facilities, there was no difference in the frequency of use of chemoradiation versus RT by facility type.

Overexpression of p53 protein and outcome of patients treated with chemoradiation for carcinoma of the anal canal: a report of randomized trial RTOG 87-04. Radiation Therapy Oncology Group.

BACKGROUND: Despite encouraging results with chemoradiation as the primary means of managing carcinoma of the anal canal, approximately 20% of patients will develop a local recurrence. This study examined the prognostic significance of p53 nuclear protein overexpression in the pretreatment biopsies of patients treated with chemoradiation for epidermoid carcinoma of the anal canal. METHODS: All patients were treated in a prospective, randomized Radiation Therapy Oncology Group trial (RTOG 87-04) in which radiotherapy to the pelvis was compared with concurrent 5-fluorouracil (5-FU) or 5-FU and mitomycin-C. Formalin fixed, paraffin embedded blocks or unstained slides from the pretreatment biopsies of 64 patients were obtained from referring institutions and evaluated immunohistochemically with the polyclonal p53 antibody CM-1. A multivariate analysis was conducted to analyze overexpression of p53 in terms of locoregional control, no evidence of disease (NED), and overall survival. RESULTS: p53 protein was overexpressed in 48.4% of the cases. Although not statistically significant, there was a trend for patients whose tumors overexpressed p53 to have inferior locoregional control (52% vs. 72%, P = 0.13), NED survival (52% vs. 68%, P = 0.27), and absolute survival (58% vs. 78%, P = 0.14). Of all the pretreatment factors analyzed, only International Union Against Cancer stage was predictive of outcome in multivariate analysis. Among those patients whose tumors overexpressed p53, there was a trend toward improved outcome in the arm that received 5-FU and mitomycin-C compared with the arm that received 5-FU only. CONCLUSIONS: Overexpression of the p53 protein may be associated with inferior outcome for patients managed with definitive chemoradiation for epidermoid carcinoma of the anal canal.

Anemia is associated with decreased survival and increased locoregional failure in patients with locally advanced head and neck carcinoma: a secondary analysis of RTOG 85-27.

PURPOSE: The purpose of the present study is to investigate the strength of association between anemia and overall survival, locoregional failure, and late radiation therapy (RT) complications in a large prospective study of patients with advanced head and neck cancer treated with conventional radiotherapy with or without a hypoxic cell sensitizer. METHODS AND MATERIALS: Between March 1988 and September 1991, 521 patients with Stage III or IV squamous cell carcinoma of the head and neck were entered into a randomized trial examining the addition of etanidazole (SR 2508) to conventional radiation therapy (RT) (66-74 Gy in 33-37 fractions, 5 days a week). Patients with hemoglobin (Hgb) levels measured and recorded prior to the second week of RT were included in this secondary analysis. Hemoglobin levels were stratified as normal (> or = 14.5 gm% for men, > or = 13 gm% for women) or anemic (< 14.5 gm% for men, < 13 gm% for women). Locoregional failure rates were calculated using the cumulative incidence approach. Overall survival was estimated according to the Kaplan-Meier method. Late RT toxicity was scored according to the RTOG morbidity scale. Differences in rates of overall survival, locoregional failure, and late complications were tested by the Cox proportional hazard model. RESULTS: Of 504 eligible patients, 451 had a Hgb level measured and recorded prior to the second week of RT. One hundred sixty-two patients (35.9%) were considered to have a normal Hgb level and 289 patients (64.1%) were considered to be anemic. The estimated survival rate is 35.7% at 5 years in patients with a normal Hgb, versus 21.7% in anemic patients (p = 0.0016). The estimated locoregional failure rate is 51.6% at 5 years in patients with a normal Hgb, versus 67.8% in anemic patients (p = 0.00028). The estimated rate of grade 3 or greater toxicity is 19.8% at 5 years in patients with a normal Hgb, versus 12.7% in anemic patients (p = 0.063). On multivariate analysis, several variables were found to be independent predictors of survival including: T stage, Karnofsky performance status, N stage, age, total radiation dose to the primary, and Hgb level. Independent predictors of locoregional control included T stage, Karnofsky performance status, N stage, radiation dose, and Hgb level. The only variables which predicted for the development of late RT complications were gender (p = 0.0109) and age (p = 0.0167). These findings were consistent regardless of whether Hgb level was considered a dichotomous or continuous variable. CONCLUSION: Low Hgb levels are associated with a statistically significant reduction in survival and an increase in locoregional failure in this large prospective study of patients with advanced head and neck cancer. Hgb level should be considered as a stratification variable in subsequent studies of head and neck cancer. Strategies to increase Hgb prior to RT in patients with head and neck cancer may lead to improved survival and loco-regional control.

Patterns of care study decision tree and management guidelines for esophageal cancer. American College of Radiology.

PURPOSE: The Patterns of Care Study (PCS) of the American College of Radiology periodically develops a decision tree and current management guidelines for major malignancies where radiation has an important role. The decision tree is a framework which depicts the division of patients into treatment groups. The treatment guidelines are useful in management and also serve as a starting point for quality assessment. For the first time, PCS decided to develop consensus management guidelines for esophageal cancer. MATERIALS AND METHODS: A consensus panel was convened to define the key issues and develop guidelines for esophageal cancer management. A modified Delphi process was used to achieve consensus. RESULTS: The consensus panel developed guidelines for the management of patients with adenocarcinoma or squamous cell carcinoma of the esophagus with a Karnofsky performance status of over 50. Patients with clinical stage I or II esophageal cancer can be treated with curative intent using either a primary surgical or primary chemoradiation approach. For patients with clinical stage III malignancy, where the most common approaches are palliative, surgical resection is generally not recommended and chemoradiation is the preferred treatment. CONCLUSION: The PCS has developed treatment guidelines for esophageal cancer based on consensus committee deliberations. These guidelines can be useful for those who manage esophageal cancer.

High dose chemoradiotherapy followed by esophagectomy for adenocarcinoma of the esophagus and gastroesophageal junction: results of a phase II study of the Eastern Cooperative Oncology Group.

BACKGROUND: To assess the toxicity, local response, and survival associated with multimodality therapy in a cooperative group setting, patients with biopsy-proven clinical Stage I or II adenocarcinoma of the esophagus (staged according to 1983 American Joint Committee on Cancer criteria) or gastroesophageal junction were treated with concomitant radiation and chemotherapy followed by esophagectomy. METHODS: Radiotherapy was administered in daily 2-gray (Gy) fractions 5 days a week until a total of 60 Gy was reached. 5-fluorouracil (5-FU) was infused continuously at a dose of 1000 mg/m2/day for 96 hours on Days 2-5 and 28-31. On Day 2, a 10 mg/m2 bolus of mitomycin was injected intravenously. Esophagectomy was performed 4-8 weeks following completion of the radiotherapy. RESULTS: During the 18-month study period (August 1991 through January 1993), 46 eligible patients were accrued from 21 institutions. Eight patients were Stage I and 38 Stage II. Eighty-seven percent of patients (40 of 46) received 6000 centigray (cGy), and all received >5000 cGy. Seventy-eight percent of patients (36 of 46) received >90% of the planned 5-FU dose. Follow-up ranged from 11 to 36 months (median, 22 months). There were eight treatment-related deaths; two were preoperative (from adult respiratory distress syndrome) and six were postoperative. Complete or partial response prior to esophagectomy was observed in 63% of cases, stable disease in 15%, and progression in 20%. Thirty-three patients underwent esophagectomy (transhiatal, n=14; Ivor Lewis, n=16; other, n=3). No tumor was found in the specimens resected from 8 of these 33 patients; this represented a pathologic complete response rate of 17% overall and 24% for those who underwent esophagectomy. Overall median survival was 16.6 months, 1-year survival 57%, and 2-year survival 27%. Survival was significantly worse for patients with circumferential cancers (median, 18.1 months vs. 8.3 months; P <0.05). CONCLUSION: High dose radiation therapy with concurrent 5-FU and mitomycin may be administered to patients with esophageal adenocarcinoma with acceptable morbidity. However, in a cooperative group setting, esophagogastrectomy following intensive chemoradiotherapy is associated with excessive morbidity and mortality. Circumferential tumor growth is a significant adverse prognostic factor.

Phase I dose escalating trial of hyperfractionated pre-operative chemoradiation for locally advanced rectal cancer.

PURPOSE: To determine the acute toxicity, post-operative complications, pathologic response and extent of downstaging to high dose pre-operative radiation using a hyperfractionated radiation boost and concurrent chemotherapy in a prospective Phase I trial. MATERIALS & METHODS: To be eligible for this study, patients had to have adenocarcinoma of the rectum less than 12 cm from the anal verge with either Stage T4 or T3 but greater than 4 cm or greater than 40% of the bowel circumference. All patients received 45 Gy pelvic radiation (1.8 Gy per fraction). Subsequent radiation was given to the region of the gross tumor with a 2 cm margin. This "boost" treatment was given at 1.2 Gy twice daily to a total dose of 54.6 Gy for Level I, 57 Gy for Level II, and 61.8 Gy for Level III. 5-FU was given at 1g/m2 over 24 hours for a four day infusion during the first and sixth weeks of radiation, with the second course concurrent with the hyperfractionated radiation. Surgical resection was carried out 4-6 weeks following completion of chemoradiation (in curative cases) and additional adjuvant chemotherapy consisting of 5-FU and Leucovorin was given for an additional 4 monthly cycles Days 1 through 5 beginning four weeks post surgery. RESULTS: Twenty-seven patients, age 40-82 (median 61), completed the initial course of chemoradiation and are included in the analysis of toxicity. The median follow-up is 27 months (range 8-68). Eleven patients were treated to a dose of 54.6 Gy, nine patients to 57 Gy, and seven patients to 61.8 Gy. Twenty-one patients had T3 tumors, and six patients T4 tumors. Grade III acute toxicity from chemoradiation included proctitis (5 patients), dermatitis (9), diarrhea (five), leukopenia (1), cardiac (1). Grade IV toxicities included one patient with diarrhea (on dose Level I) and one patient (on dose Level III) with cardiac toxicity (unrelated to radiation). Surgical resection consisted of abdominal perineal resection in 16 and low anterior resection in 7. Four patients did not undergo a curative resection; three initially presented with metastases and one developed metastasis during the pre-operative regimen. Post-operative complications included pelvic or perineal abscess in two (on dose Levels I & II), and delayed wound healing in two (one of whom, on dose Level III, developed perineal wound dehiscence requiring surgical reconstruction). Of the 23 patients who had a curative resection, four manifested pathologic complete responses (17.4%). Thirteen of 23 patients (57%) had evidence of pathologic downstaging and only 1/23 patients (on dose Level I) had a positive resection margin. Of these 23 patients (with a minimum follow-up of 8 months), the patient with positive margins was the only one who developed a local failure (Fisher's Exact p=.04). The 3-year actuarial OS, DFS and LC rates are 82%, 72% and 96%, respectively. Twelve of 13 patients (92% at 3 years) > or = 61 years vs. 5/10 patients (45% at 3 years) < 61 years remained disease-free (log-rank p=0.017). CONCLUSION: This regimen of high dose pre-operative chemoradiation employing a hyperfractionated radiation boost is feasible and tolerable and results in significant downstaging in locally advanced rectal cancer. The vast majority of patients (96%) achieved negative margins, which appears to be a prerequisite for local control (p= 0.04). Older age (> or =61 years) was a significant predictor for improved DFS. This regimen (at dose Level III, 61.8 Gy) is currently being tested in a Phase II setting.

The structure of radiation oncology in the United States in 1994.

PURPOSE: 1) to measure the basic structural characteristics of radiation oncology facilities for the entire country, providing census data for January 1, 1994; 2) to allow comparisons by facility type, equipment, or patient load; 3) to allow comparisons of the patterns of equipment and personnel to previous surveys; and 4) to make a preliminary assessment of the geographic distribution of facilities. METHODS AND MATERIALS: A mail survey verified whether each potential facility delivered megavoltage radiation therapy and collected data on treatment machines, other equipment, personnel, new patients, and procedures performed. Responses were obtained from 99% of potential facilities. The census data was summarized for the entire country, by hospital-based, free-standing, or federal category, by single or multiple treatment machine group, and by new patient load category. Geographic analysis compared the center of radiation oncology facilities with the center of cities or towns having a population of more than 25,000 residents in 1990. RESULTS: In the United States in 1994, 1542 facilities delivered megavoltage radiation therapy, with 2744 treatment machines, 2777 FTE radiation oncologists, 1349 FTE physicists, 1314 FTE dosimetrists, and 7167 FTE radiation therapists. They treated 560,262 new patients and reported that 60% were treated with curative intent. Eighty percent of the facilities had a dedicated treatment planning computer and 15% had a time-sharing treatment-planning computer, but 5% had no treatment-planning capability. Ninety-five percent of all facilities reported that patients were simulated at that facility. Fourteen percent of all facilities used hyperthermia, 8% intraoperative radiation therapy, 12% stereotactic radiosurgery, and 19% conformal therapy with 3D planning. Of all facilities 35% reported having a dedicated CT scanner and 12% reported having a CT simulator in the department. The distributions of these measures were reported for hospital-based, free-standing, and federal facilities, for single-treatment machine, and multiple-treatment machines facilities, and for three categories based on patient load. Only 18 cities with a population over 25,000 were more than 25 miles from a radiation oncology facility, of which only eight were more than 50 miles from a facility. CONCLUSION: The Facilities Surveys continue to provide a unique source of census data on radiation oncology in the United States, allowing comparisons by facility group and over time.

Neck failure in T2N0 squamous cell carcinoma of the true vocal cords: the Fox Chase experience and review of the literature.

There is a need for additional data in the literature regarding elective nodal irradiation in the treatment of T2N0 squamous cell carcinoma of the glottic larynx. We examined the experience at the Fox Chase Cancer Center and performed a literature review in order to define a treatment policy. Sixteen patients with T2 squamous cell carcinoma of the glottic larynx were treated with radiation therapy. Ten patients were irradiated to the larynx alone and six to the larynx and regional nodes. None of the patients in our series experienced a nodal recurrence regardless of whether the neck was electively irradiated. A literature review of 413 patients revealed that 2.6% of patients who did not have their nodes electively irradiated and had their primary tumor controlled experienced a nodal failure compared to 3.7% if the primary and regional nodes were irradiated (P = 0.88). Similarly, there was no significant difference in the rate of nodal failure for patients who experienced a recurrence at the primary site regardless of whether they received elective nodal irradiation (P = 0.36). We recommend treatment to the larynx alone since our policy is to treat the regional nodes only when the incidence of occult lymphadenopathy in the neck exceeds 15%.

Dose estimation to critical organs from vertex field treatment of brain tumors.

PURPOSE: Radiation management of intracranial tumors may require a noncoplanar vertex field that often irradiates the entire length of the body. In view of radiation related risks to the normal tissues dose estimation to the extracranial organs such as the thyroid gland, spinal cord, heart, and genitalia is performed for a vertex field. METHODS AND MATERIALS: A vertex field used clinically was reproduced on an anthropomorphic Rando phantom to measure radiation dose to various organs in the primary beam. Three photon beams (4, 6, and 10 MV), and two high energy electron beams (16 and 20 MeV) were used. Dosimetry was performed with an ion chamber sandwiched between phantom slices at the appropriate positions. All doses were normalized to the target dose at a depth of 5 cm. The effect of the head position was studied by rotating the gantry angle up to +/-20 degrees to mimic the extension and flexion of the head. Theoretical calculation was performed using an exponential best fit to the depth dose table to estimate the dose to various points and compare with the measured dose. RESULTS: The measured normalized dose to the cervical cord, thyroid, heart, and female and male gonads are 60, 36, 16, 2.5, and 1.6%, respectively, for a 6 MV photon beam. The dose from 4 MV and 10 MV are slightly lower and higher, respectively. Doses from electron beams are about a factor of 4-10 lower than those of the photon beams. The measured gonadal dose from the primary beam is <5% of the target dose for all energies used in the study. The actual value, however, is dependent on the body structure, length, and the posture of the patient. A +5 degree head flexion had little effect on the dose to the various parts of the body. The head rotations greater than +/-10 degrees produced relatively lower doses by a factor of 10(-2) to the organs at distances greater than 40 cm from the prescription point. The radiation doses to the different critical organs estimated from the fitted curves are lower than the measured doses up to 35%. CONCLUSIONS: When a vertex field is used for the treatment of the brain tumors, the entire axial length of the body is irradiated which adds to the integral dose. Unlike the scattered and leakage radiation, the primary dose to extracranial critical organs is greater for higher energies. For a 10 MV beam the ovary and testis at a distance of 80 cm and 90 cm may receive a dose of 4.2 and 3%, respectively, of the target dose. The gonadal dose could be quite significant if the entire treatment is delivered using a vertex field. For pediatric and smaller patients, dose to the critical organs at known distances could be estimated from the empirical equation obtained from the measured data. While the risk-benefit ratio is often evaluated and acceptable for treating malignant tumors, the long-term complications need thorough assessment in younger and curable patients. In view of radiation carcinogenesis and genetic burden, dose reduction to critical organs should be considered using a 3D planning system to arrange beams in other nonaxial planes and by considering electron beams for the vertex field.