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Biomedical subjects

R L Foote

Publications and source records attributed to R L Foote.

At least 55 records · Page 3Linked to original sources
PubMed1995

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.

Adult↗
PubMed1995

Prophylactic cranial irradiation in limited-stage small cell lung cancer.

BACKGROUND: The role of prophylactic cranial irradiation (PCI) for patients with limited-stage small cell lung cancer (LSSCLC) remains a controversial issue. This study evaluated PCI in patients with LSSCLC who achieved a complete response to initial chemotherapy. METHODS: A retrospective case study of all nonprotocol patients with LSSCLC examined at our institution from 1982 to 1990 was performed. Of the 67 nonprotocol patients who were treated with combination chemotherapy (cyclophosphamide-based) and thoracic radiotherapy during those years, 43 achieved a complete response. Twenty-four patients received prophylactic cranial irradiation (PCI+) (25-36 Gy in 10-16 fractions), and 19 did not (PCI-) at the physician's or patient's discretion. RESULTS: The distribution of prognostic factors between the PCI+ and PCI- groups was well balanced. Of the PCI+ patients, the 2-year actuarial freedom from relapse in the central nervous system was 93% versus 47% for the PCI- patients (log rank analysis, P = 0.001). An initial central nervous system relapse developed in 2 of the 24 PCI+ patients as the only site of failure versus 7 of 19 PCI- patients (P = 0.003). The 2-year actuarial overall survival was 50% for the PCI+ patients versus 21% for the PCI- patients (P = 0.01). The addition of prophylactic cranial irradiation was the only significant factor contributing to an improvement in time to central nervous system relapse and survival for the PCI+ patients. There were five patients alive at the time of this report, and all received prophylactic cranial irradiation. None had cognitive or neurologic impairment. CONCLUSIONS: Prophylactic cranial irradiation may contribute to improved survival in patients with LSSCLC who achieve a complete response after chemotherapy and thoracic radiation therapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Alleviation of cytotoxic therapy-induced normal tissue damage.

Cytotoxic chemotherapy and radiation therapy damage normal body tissues, resulting in stomatitis, conjunctivitis, esophagitis, proctitis, and dermatitis. Pursuant to this, the North Central Cancer Treatment Group has developed a series of clinical trials designed to study antidotes for these pathologic processes. These trials have demonstrated clinically helpful therapies (eg, oral cryotherapy for decreasing mucositis induced by 5-fluorouracil) and also have demonstrated lack of benefit for other proposed treatments. Results from several ongoing clinical trials should become available in the near future.

Chlorhexidine↗
PubMed1994

Tonsil cancer. Patterns of failure after surgery alone and surgery combined with postoperative radiation therapy.

BACKGROUND: The authors determined the patterns of treatment failure in patients treated with surgery alone or surgery combined with postoperative radiation therapy for squamous cell carcinoma of the tonsil. METHODS: Seventy-two patients underwent surgery alone (56) or surgery and postoperative adjuvant radiation therapy (16). All patients were followed up until death (40 patients) or for a minimum of 3.5 years. For patients treated with surgery alone, clinic notes, operative notes, and pathology reports and slides were reviewed to identify clinical or pathologic predictors of recurrence above the clavicles, cause-specific survival, and overall survival. For patients undergoing postoperative adjuvant radiation therapy, demographic, treatment, and pathologic variables were analyzed to identify factors associated with control of disease above the clavicles, disease-free survival, and overall survival. RESULTS: The main pattern of treatment failure was above the clavicles. It occurred in 39% of patients treated with surgery alone and was significantly related (P = 0.002) to the overall clinical TNM stage. Disease recurrence above the clavicles occurred in 31% of patients undergoing surgery and postoperative adjuvant radiation therapy, despite their more advanced neck disease. Five-year overall survival for patients with clinical Stage III and IV disease who were treated with surgery and post-operative adjuvant radiation therapy was 100% and 78%, respectively. Five-year overall survival for patients treated with surgery alone who had clinical Stage III, IVA, or IVB disease was 56%, 43%, and 50%, respectively. CONCLUSION: We recommend postoperative adjuvant radiation therapy for patients with clinical Stage III or IV squamous cell carcinoma of the tonsil who have undergone complete surgical resection because this appears to improve control of disease above the clavicles and overall survival.

Adult↗
PubMed1994

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.

Adult↗
PubMed1994

Tumor-ablative surgery, microvascular free tissue transfer reconstruction, and postoperative radiation therapy for advanced head and neck cancer.

OBJECTIVE: The objectives of this study were to determine whether the combination of complex tumor-ablative surgery and microvascular free tissue transfer reconstruction delays the onset of postoperative radiation therapy, whether free tissue transfers are lost after a course of radiation therapy, and what patterns of tumor recurrence and survival rates are present in patients who undergo this type of multidisciplinary treatment. DESIGN: A retrospective review was conducted in 37 patients who underwent tumor-ablative surgery and reconstruction between November 1987 and August 1991. MATERIAL AND METHODS: Of the 30 men and 7 women who underwent tumor-ablative surgery, microvascular free tissue transfer reconstruction, and postoperative radiation therapy, recurrent or T4 primary tumors were treated in 84%. Sixty-two percent of the patients had nodal metastatic disease. The median dose of postoperative irradiation was 60 Gy (range, 32.4 to 76.8). Follow-up in all patients was until death (21 patients) or for a median of 17.5 months (range, 4.1 to 43.2). RESULTS: The median duration of overall survival and the 2-year overall survival rate were 17 months and 46%, respectively. For cause-specific survival, the median duration and 2-year rate were 17 months and 50%, respectively. Local recurrence developed in 8 patients, neck recurrence in 10, and distant metastatic disease in 11. No microvascular free tissue transfers failed. CONCLUSION: Radiation therapy can begin in most patients within 8 weeks postoperatively, microvascular free tissue transfers seem to tolerate postoperative radiation therapy well at the doses administered, and the rates of local and neck control are reasonable relative to the advanced stage of the cancers treated.

Adult↗
PubMed1994

Radiation therapy for squamous cell carcinoma of the tonsil.

OBJECTIVE: To characterize the patient population referred for radiation therapy for tonsillar cancer and to assess the effectiveness of use of only radiation therapy in this population. DESIGN: We retrospectively reviewed the medical records of 21 patients referred to the Mayo Clinic in Rochester, Minnesota, from 1970 through 1988 for radiation therapy for squamous cell carcinoma of the tonsillar region. MATERIAL AND METHODS: The median age of the 21 study patients was 65 years (range, 45 to 92), and the male:female ratio was 12:9. In all patients, follow-up continued until death or for 2.25 to 16.25 years. Of the 21 patients, 17 had tumors that were either surgically unresectable or medically inoperable, and 20 had clinical stage III or IV disease. The median total dose of irradiation was 55 Gy. RESULTS: Local control of the tonsillar cancer was as follows: T2, four of five patients; T3, seven of seven; and T4, five of nine. Thus, the local control rate was 76%. No associations were discovered among local control, total dose of radiation therapy, dose per fraction, overall duration of treatment, age, sex, or reason for referral for radiation therapy. Control of metastatic cervical adenopathy was as follows: clinical stage N1, seven of seven patients; N2, six of seven; and N3, one of one. (Six study patients had no nodal involvement.) The estimated 5-year cause-specific survival and overall survival rates were 77% and 31%, respectively. CONCLUSION: This study substantiates the effectiveness of radiation therapy in patients with squamous cell carcinoma of the tonsil.

Actuarial Analysis↗
PubMed1994

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.

Aged↗
PubMed1994

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.

Actuarial Analysis↗
PubMed1993

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.

Adolescent↗
PubMed1993

Radiation treatment of heterotopic bone formation in the temporomandibular joint articulation.

PURPOSE: The efficacy and toxicity of radiation therapy used for preventing re-formation of heterotopic bone involving the temporomandibular joint are assessed. METHODS AND MATERIALS: Ten patients (15 TMJs) with bony ankylosis of the TMJ were referred after reconstruction with costochondral graft, gap arthroplasty, or debridement of heterotopic bone. Treatment consisting of 10 Gy was delivered early postoperatively to a field encompassing the TMJ with adequate margin. Response to therapy was assessed by comparison of routine roentgenograms obtained preoperatively, immediately postoperatively, and at last follow-up; the Turlington-Durr grading system was used. Median duration of postoperative follow-up was 19 months. RESULTS: Radiation therapy prevented ectopic bone re-formation in 10 (69%) of 15 TMJs with prior bony ankylosis. Of the 15 TMJs, 13 (87%) had improvement in their Turlington-Durr scores compared with the preoperative scores. Development of ectopic bone formation was prevented in 9 (90%) of 10 TMJs rendered Turlington-Durr grade 0 postoperatively. Eight of the 10 patients have remained asymptomatic. Treatment was well tolerated. The only complication experienced was parotitis in three patients. CONCLUSION: Radiation therapy is useful for prevention of heterotopic bone redevelopment after TMJ operation. We recommend 10 Gy in 5 fractions beginning early postoperatively for high-risk patients. This strategy appears beneficial in this young patient population, who suffer significant pain and functional impairment in the TMJ articulation.

Adolescent↗
PubMed1993

Doses to radiation sensitive organs and structures located outside the radiotherapeutic target volume for four treatment situations.

This study documents dosage to radiation sensitive organs/structures located outside the radiotherapeutic target volume for four treatment situations: (a) head and neck, (b) brain (pituitary and temporal lobe), (c) breast and (d) pelvis. Clinically relevant treatment fields were simulated on a tissue-equivalent anthropomorphic phantom and subsequently irradiated with Cobalt-60 gamma rays, 6- and 18-MV x-ray beams. Thermoluminescent dosimeters and diodes were used to measure absorbed dose. The head and neck treatment resulted in significant doses of radiation to the lens and thyroid gland. The total treatment lens dose (300-400 cGy) could be cataractogenic while measured thyroid doses (1000-8000 cGy) have the potential of causing chemical hypothyroidism, thyroid neoplasms, Graves' disease and hyperparathyroidism. Total treatment retinal (400-700cGy) and pituitary (460-1000 cGy) doses are below that considered capable of producing chronic disease. The pituitary treatment studied consisted of various size parallel opposed lateral and vertex fields (4 x 4 through 8 x 8 cm). The lens dose (40-200 cGy) with all field sizes is below those of clinical concern. Parotid doses (130-1200 cGy) and thyroid doses (350-600 cGy) are in a range where temporary xerostomia (parotid) and thyroid neoplasia development are a reasonable possibility. The retinal dose (4000 cGy) from the largest field size (8 x 8 cm2) is in the range where retinopathy has been reported. The left temporal lobe treatment also used parallel opposed lateral and vertex fields (7 x 7 and 10 x 10 cm). Doses to the pituitary gland (5200-6200 cGy), both parotids (200-6900 cGy), left lens (200-300 cGy) and left retina (1700-4500 cGy) are capable of causing significant future clinical problems. Right-sided structures received insignificant doses. Secondary malignancies could result from measured total treatment thyroid doses (670-980 cGy). Analysis of three breast/chest wall and regional nodal irradiation techniques demonstrated a 25-50% decrease in secondary lung dose with use of independent collimation compared to use of custom alloy blocking material. However, it is unlikely that a reduction in secondary dose of this magnitude would reduce the risk of treatment sequellae. In four-field "box" pelvic irradiation, secondary testes dose may result in temporary (clamshell shield) or permanent azoospermia, but is unlikely to impair androgen production.

Brain↗
PubMed1993

Malignant tracheoesophageal fistula in patients with esophageal cancer.

BACKGROUND: Patients with esophageal cancer and a malignant tracheoesophageal fistula (TEF) have an extremely poor prognosis. Additionally, these patients often are denied treatment with radiation therapy because there is concern that these treatments may increase the size and associated problems of the TEF. METHODS: To determine the appropriate treatment (use of radiation therapy) for patients with esophageal cancer and malignant TEF, a review was performed of all such cases seen at the Mayo Clinic between 1971 and 1991. RESULTS: Between 1971 and 1991, 41 patients with malignant TEF arising as a result of esophageal cancer were seen at the Mayo Clinic in Rochester. Twenty-eight of these cancers were locally recurrent, and this group of patients had a uniformly poor outcome (median survival time, 1.4 months). Thirteen patients had a malignant TEF and had not received previous treatment for their esophageal cancer. The median survival length was 4 months for this group of patients. Of the 41 patients in this study, 10 received radiation therapy for their malignant TEF (30-66 Gy). The median survival length of this group of patients was 4.8 months. Six of these 10 patients died of metastatic disease (median survival length, 9 months), and there was no evidence of progression of the local tumor. Four of these 10 patients died of local progression of the malignancy (median survival length, 3 months). CONCLUSIONS: Radiation therapy did not increase the severity of the TEF. The authors conclude that radiation therapy can be administered safely in patients with TEF resulting from esophageal cancer. In some patients, radiation treatment may contribute to stabilization of the local tumor process (60% of patients treated with radiation therapy died of metastatic disease without local progression of tumor); however, all patients in this study eventually died of esophageal cancer.

Adenocarcinoma↗
PubMed1993

Low-versus high-energy photon beams in radiotherapy for lung cancer.

This retrospective study analyzed the outcome of lung cancer patients who were treated with either 4-MV or 10-MV photons. From October 1979 through December 1982, 126 patients with locally advanced, unresectable or medically inoperable, nonmetastatic non-small cell lung cancer were treated in a prospective trial in which they were randomly assigned to one of three chemotherapy combinations and thoracic radiotherapy. The patients were stratified by cell type, extent of operation, age, sex, and status of supraclavicular lymph nodes. All patients were followed until death or for a minimum of 4.8 years. Of the 102 evaluable patients, 98 were treated with either 4-MV or 10-MV photons (49 patients in each group). Outcomes examined included best primary tumor response, time to first local (in-field) recurrence, disease-free survival, and overall survival. No significant differences were detected between the patients treated with 4-MV or 10-MV photons for several important prognostic and treatment factors or for any of the study outcomes, including first local (in-field) recurrence, disease-free survival, and overall survival. For the group of 98 patients treated with either 4-MV or 10-MV photons, the estimated 2-year freedom from first local (in-field) recurrence was 47.7%. The estimated 2-year disease-free and overall survivals were 21.6% and 28.6%, respectively.

Adenocarcinoma↗
PubMed1993

Role of radiation therapy in the management of lung cancer.

Most patients who have lung cancer will receive radiation therapy at some point during the course of their disease. For patients with non-small-cell lung cancer, radiation therapy is sometimes used after complete resection, particularly in patients with lymph node involvement. In addition, irradiation is commonly used after incomplete resection. In patients with unresectable non-small-cell lung cancer, radiation therapy alone is typically used, although recent studies of a combination of chemotherapy and radiation therapy, or radiation therapy given in twice-daily fractions, have yielded promising results. For patients with small-cell lung cancer who have limited (that is, nonmetastatic) disease, the addition of thoracic radiation therapy to chemotherapy has improved survival over that with chemotherapy only. The role of prophylactic cranial irradiation in small-cell lung cancer remains controversial. Radiation therapy has a major role in the management of locally recurrent and metastatic lung cancer. Both the bones and the brain are common metastatic sites in patients with lung cancer. Radiation therapy provides effective palliation of symptoms from these and other metastatic lesions.

Carcinoma, Non-Small-Cell Lung↗