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W H Morrison

Publications and source records attributed to W H Morrison.

At least 37 records · Page 2Linked to original sources
PubMed1998

Fermentation of maize bran, oat bran, and wheat bran by Bacteroides ovatus V975.

Bacteroides ovatus is a Gram-negative obligate anaerobe that was isolated from the human colon and is capable of utilizing xylan. The objective of this study was to evaluate the ability of B. ovatus V975 to digest maize bran, oat bran, and wheat bran as well as the isolated cell walls from each bran source. Strain V975 was incubated in basal medium that contained either 0.1 or 0.3 g of each bran or each bran cell wall for 0, 24, 48, and 72 h. Acetate and succinate were the main products detected from each fermentation; however, less of each end product was produced from the isolated cell walls than from each bran. More of the oat bran was digested (in vitro dry matter disappearance = 74.8%) during the 72 h incubation than any other bran source. While each bran contained arabinose and xylose, more glucose, galactose, and mannose were utilized by strain V975 during the 72-h incubation than either pentose sugar. Compared with each bran, the bran cell walls had lower concentrations of most sugars, and more glucose than any other sugar was utilized by strain V975. These results suggest that strain V975 preferentially utilizes glucose, galactose, and mannose in each bran, while glucose is the main sugar fermented in bran cell walls.

Acetates↗
PubMed1998

Ethmoid sinus carcinomas: natural history and treatment results.

PURPOSE: This retrospective study was undertaken to assess the clinical features and results of treatment of carcinomas of the ethmoid sinus. MATERIALS AND METHODS: The records of 34 patients with ethmoid sinus carcinomas treated with curative intent at the U.T.M.D. Anderson Cancer Center (UTMDACC) between January 1969 and December 1993 were reviewed. The age of the patients ranged from 28 to 73 years with a median of 57 years. There were 28 Whites, four Hispanics, one Black and one Asian. A simple staging based on anatomical criteria was used to describe the extent of the disease. Six patients had T1, 13 patients had T2 and 15 patients had T3 disease. Twenty-one patients were treated with surgery plus radiation and 13 patients were treated with radiotherapy alone; nine patients received adjuvant chemotherapy. Radiation was given at approximately 2 Gy per fraction to total doses of 50 Gy preoperatively, 52-66 Gy (median 60 Gy) postoperatively and 50-70 Gy (median 63 Gy) when no surgery was performed. RESULTS: The actuarial 5-year overall, disease-free and disease-specific survival rates were 55%, 58% and 63%, respectively. The actuarial 5-year local control rate was 71% for the whole group (74% for surgery plus radiation and 64% for radiation alone). Local recurrence occurred in nine patients, nodal relapse occurred in three patients and distant metastases occurred in four patients. Histologically proven dura mater invasion was associated with a poorer local control rate in patients undergoing surgery and radiation. The simple T-staging system used in this study was a good discriminator for local control. Of nine patients receiving chemotherapy, three had complete responses and four had partial responses; six of the seven responders had undifferentiated carcinoma. Severe complications of therapy occurred in patients treated between 1969 and 1984 and consisted mainly of visual impairment and brain necrosis. CONCLUSIONS: This retrospective review of a large single institutional experience showed that ethmoid sinus carcinomas have a tendency for extensive local invasion but a low propensity for lymphatic and hematogenous spread. Hence, local recurrence was the main cause of cancer-related death. Combined treatment with surgery and postoperative irradiation yielded the highest local control rate. However, radiotherapy alone eradicated two-thirds of primary tumors and, consequently, is a reasonable alternative treatment for patients with medical contraindications to surgery. For patients who underwent surgery and radiotherapy, the presence of histologically proven dura mater invasion was associated with a higher local recurrence rate. Severe radiation complications have been rare with the contemporary radiotherapy technique. Chemotherapy induced excellent responses in undifferentiated carcinoma but its impact on overall disease control is unclear in this small series of patients.

Adult↗
PubMed1998

Radiation therapy for early stage (T1-T2) sarcomatoid carcinoma of true vocal cords: outcomes and patterns of failure.

Sarcomatoid carcinoma of head and neck mucosal sites is a rare high-grade malignancy that may cause diagnostic and therapeutic controversies. A characteristic of this entity consistently reported but not entirely validated is its relative radioresistance and the general belief is that surgery is the treatment of choice. The objective of this retrospective study was to determine if patients treated with radiation for early glottic sarcomatoid carcinoma had worse outcomes than those achieved with irradiation for the more typical squamous cell carcinoma. Twenty-eight cases of early stage (T1-T2) sarcomatoid carcinoma of the larynx treated with definitive doses of megavoltage irradiation between 1969 and 1995 at The University of Texas M. D. Anderson Cancer Center form the cohort for this analysis. All pathologic material was reviewed to confirm the diagnosis. All tumors manifested spindle cell features with marked cytomorphologic abnormalities characteristic of this entity. Sixteen tumors (57%) had the more typical polypoid gross morphology of sarcomatoid carcinoma. Twenty-one patients (75%) were staged T1 and seven patients (25%) had stage T2 disease. All patients were treated with small laryngeal fields, median size 20 cm2, and to a median dose of 65 Gy. Follow-up ranged from 1.5 to 24 years (median, 10 years). Four patients (14%) had local disease recurrence, and all had salvage total laryngectomies and remained free of local disease. The 5-year actuarial local control rates for patients with T1 and T2 lesions were 94% and 54%, respectively. Only one patient developed regional and distant disease. The 10-year actuarial disease-specific and overall survival rates were 92% and 63%, respectively. Patients with early stage sarcomatoid carcinoma of the glottis treated with radiation had similar control rates to irradiated patients with similar volume disease with the more typical squamous cell carcinoma. The authors contend that the histologic diagnosis of sarcomatoid carcinoma by itself should not influence the decision to treat a patient with early stage glottic disease with irradiation.

Adult↗
PubMed1997

Concomitant boost radiotherapy for squamous carcinoma of the tonsillar fossa.

PURPOSE: To assess the efficacy of a concomitant boost fractionation schedule of radiotherapy for treating patients with squamous carcinoma of the tonsillar fossa. PATIENTS AND METHODS: Between December 1983 and November 1992, 83 patients with squamous carcinoma of the tonsil were treated with concomitant boost fractionation. The distribution of American Joint Committee on Cancer T stages was TX-4, T1-5, T2-29, T3-41, T4-4; N stages were NX-1, N0-26, N1-13, N2-31, N3-12. Patients were treated with standard large fields to 54 Gy in 6 weeks. The boost treatment consisted of a second daily 1.5 Gy fraction for 10-12 fractions, usually delivered during the final phase of treatment. The tumor dose was 69-72 Gy, given over 6 weeks. Twenty-one patients, who all had N2 or N3 regional disease, underwent neck dissections, either before (13 patients) or 6 weeks after radiotherapy (8 patients); the other patients were treated with radiotherapy alone. RESULTS: The 5-year actuarial disease-specific survival and overall survival rates were 71 and 60%, respectively. Patients with T2 and T3 primary tumors had 5-year actuarial local control rates of 96 and 78%, respectively. Patients with T3 disease who received the final-phase boost had a 5-year actuarial local control rate of 82%. Actuarial 5-year regional disease control rates were N0, 92%; N1, 76%; N2, 89%; and N3, 89%. The 21 patients who had neck dissections all had their disease regionally controlled. Patients presenting with nodal disease or after a node excision who were treated with radiation alone had a 5-year actuarial regional disease control rate of 79%. All but five patients had confluent Grade 4 mucositis during treatment. Severe late complications attributable to radiation included mandibular necrosis [1], in-field osteosarcoma [1], and chronic dysphagia for solid foods [5]. CONCLUSIONS: High rates of local and regional disease control were achieved with the concomitant boost fractionation schedule, with few cases of severe late morbidity. Patients with N2 and N3 neck disease were effectively treated with radiation and the selective use of neck dissections. The concomitant boost schedule is our preferred fractionation approach for treating patients with intermediate stage tonsil cancer who are not participating in our current research protocols.

Adult↗
PubMed1997

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

PURPOSE: This retrospective study was conducted to review the results of treatment and to identify prognostic factors for local and regional control in a population of 378 patients with nasopharyngeal carcinomas treated in a single institution by radiation therapy alone. METHODS AND MATERIAL: All patients were treated at The University of Texas M. D. Anderson Cancer Center between 1954 and 1992 following a consistent treatment philosophy but with evolving technique. There were 286 males and 92 females with a median age of 52 years (range: 16-86 years). The majority of the patients were Caucasian (282 patients, 75%). Thirty-two patients (8%) had one or more cranial nerve deficits. Three-fourths of the patients presented with AJCC Stage IV disease (T4, N0-3, 118 patients; T1-3, N2-3 164 patients). Histologically, 193 tumors (51%) were squamous cell carcinomas, 154 (41%) lymphoepitheliomas, and 31 (8%) unclassified carcinomas. Average total dose varied with T-stage and ranged from 60.2 to 72.0 Gy. Median follow-up time was 10 years. RESULTS: For the entire population the 5-, 10-, and 20-year actuarial survival rates were 48, 34, and 18%, respectively, with 184 patients (49%) dying of nasopharyngeal cancer. Actuarial control rates at 5, 10, and 20 years were 71, 66, and 66% for the primary site and 84, 83, and 83% for the neck. A total of 100 patients (26%) had local failures and 51 patients (13%) had regional failures with a median time to recurrence of 8.2 months and 13 months, respectively. Advanced T-stage, squamous histology, and presence of cranial nerve deficits were poor prognostic factors for local control in both univariate and multivariate analyses. N-stage and tumor histology were significant factors for neck control. Treatment year, total dose within the ranges used, and duration of treatment did not have any significant effect on local or regional control. The actuarial incidence of Grade 3-5 late complications was 16, 19, and 29% at 5, 10, and 20 years, respectively. Twelve patients (3%) died of treatment-related complications; all but one fatal complication occurred before 1971 and the other in 1976. CONCLUSIONS: This study shows very good long-term local and regional control rates for nasopharyngeal carcinomas after definitive radiotherapy and establishes a benchmark for newer treatment strategies. Improvements in treatment technique over the years have dramatically reduced the frequency of severe late complications. Patients with advanced stage tumors and differentiated squamous histology have a relatively poor prognosis when treated with conventional radiotherapy and are candidates for dose escalation or combined modality studies.

Adolescent↗
PubMed1997

Postoperative radiotherapy for malignant tumors of the parotid gland.

PURPOSE: To update our experience using postoperative irradiation in selected patients with carcinomas of the parotid gland. Outcomes of treatment with a focus on the effectiveness of the two primary techniques of radiation used for treating these tumors were evaluated. METHODS AND MATERIALS: A retrospective analysis of 166 patients with parotid gland malignancies treated in the Department of Radiotherapy at the University of Texas M. D. Anderson Cancer Center between 1965-1989 was performed. All patients were treated following surgery and did not have macroscopic disease at the time of their radiation. The most common histologies were mucoepidermoid carcinoma (28%) and adenocarcinoma (27%). Pathologic features constituting indications for postoperative radiotherapy included: inadequate margins, 104 (63%) cases; extraglandular disease extension, 82 (49%); perineural invasion 57 (34%); and nodal disease 43 (26%). Radiation was delivered through an ipsilateral field of predominantly high energy electrons in 142 patients (86%). Wedged paired 60Co fields were used to treat 19 patients. The median dose was 60 Gy, typically delivered at 2 Gy per fraction. The median follow-up time for surviving patients was 155 months. RESULTS: Forty-seven (29%) patients had disease recurrence, of whom 15 (9%) had disease recur locally and 10 (6%) regionally (neck). There was no association between the dose of radiation and local failure, except for a trend for patients with positive margins and/or named nerve involvement to have improved local control if they received doses > 60 Gy. There was no difference in failure rates in patients treated with wedged pair techniques or ipsilateral fields, but there was a higher complication rate in the former. Overall, 37 patients (22%) developed chronic sequelae attributed to radiation. Twelve patients developed decreased hearing, and 15 patients developed soft tissue or bone necrosis or exposure. CONCLUSIONS: Local and regional control rates for high risk patients with parotid gland carcinomas treated with radiation following surgery were excellent. The technique of using an ipsilateral field encompassing the parotid bed and treated with high energy electrons often mixed with photons was effective with minimal severe late toxicity. The moderate complication rate experienced in this series can be further reduced using modern techniques as described.

Adenocarcinoma↗
PubMed1997

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

PURPOSE: This retrospective study was conducted to identify the prognostic factors for distant metastasis and survival in a population of 378 patients with nasopharyngeal carcinomas treated by radiation therapy alone. MATERIALS AND METHODS: All patients were treated at the University of Texas M.D. Anderson Cancer Center between 1954 and 1992, following a consistent dose and volume prescription policy. There were 286 males and 92 females. The median age was 52 years (range: 16-86 years). The majority of the patients were white Caucasians (282 patients,75%). Tumors were classified as squamous cell carcinomas (193; 51%), lymphoepitheliomas (154; 41%), or unclassified carcinomas (31, 8%). Three fourths of the patients presented with AJCC Stage IV disease (T4, N0-3, 118 patients; T1-3, N2-3 164 patients). The treatment techniques included opposed lateral fields with or without an anteroposterior or an anterior oblique pairs for dose supplementation to the primary site. Average total doses per T-stage ranged between 60.2 and 72.0 Gy. Median follow-up time was 10 years (range 0.3 to 28.6 years). RESULTS: A total of 103 patients (27%) developed distant metastases at a median time of 8 months (range: 1-90 months). Actuarial rates for distant metastasis were 30%, 32%, 32% at 5, 10, and 20 years, respectively. Actuarial rates for disease specific survival at the same time points were 53%, 45%, and 39% with 184 patients (49%) dying of their nasopharyngeal cancer. Advanced T-stage, N-stage, and non-lymphoepithelioma histology were independent adverse prognostic factors for disease specific survival. Advanced N-stage and low neck disease were independent adverse prognostic factors for distant metastasis with a very high rate of distant metastases for those patients who presented with both adverse factors (relative risk 7.86). On average, patients with distant metastasis lived 5 months after they were diagnosed with metastatic disease (range: 0-172 months), although four patients (4%) survived more than 5 years after diagnosis. CONCLUSIONS: This study demonstrates good long term survival rates after definitive radiotherapy for patients with nasopharyngeal carcinomas. Patients with advanced and lower neck disease have the highest risk of developing distant failures. Such patients can be considered the reference risk group to test the value of adjunctive chemotherapy.

Adolescent↗
PubMed1997

Radiation therapy for nonmelanoma skin carcinomas.

Radiotherapy plays an important role in the management of appropriately selected skin carcinomas. Tumors of the eyelid, nose, and ear can be treated successfully with preservation of adjacent normal tissues. Tumors located in the embryologic fusion planes of the face can be irradiated with wide margins, either as primary or postoperative therapy. Radiotherapy has a significant role in the postoperative setting for patients with high-risk features in their pathologic specimens. Patients with NECS (Merkel cell carcinoma) have a high recurrence rate after surgical excision; these patients should undergo radiotherapy after resection of the clinically evident disease.

Basal Cell Carcinoma↗
PubMed1996

Does induction chemotherapy have a role in the management of nasopharyngeal carcinoma? Results of treatment in the era of computerized tomography.

PURPOSE: To assess the outcomes of patients with nasopharyngeal carcinoma (NPC) whose treatment was determined by computerized tomography (CT) and/or magnetic resonance imaging staging and to analyze the impact of induction chemotherapy and accelerated fractionated radiotherapy. METHODS AND MATERIALS: The analysis is based on 122 of 143 previously untreated patients with NPC treated with radiation therapy at The University of Texas M. D. Anderson Cancer Center between 1983 and 1992. Excluded were 4 patients treated with palliative intent, 4 children, 12 patients not staged with CT, and 1 patient who died of a cerebrovascular accident prior to completion of treatment. The stage distribution was as follows: AJCC Stage I-2, Stage II-7, Stage III-12, Stage IV-101; Tl-15, T2-33, T3-22, T4-52; N0-32, N1-10, N2-47, N3-32, Nx-1. Fifty-nine (48%) patients had squamous cell carcinoma; 63 (52%) had lymphoepitheliomas, undifferentiated NPC or poorly differentiated carcinoma, NOS (UNPC). Sixty-seven patients (65 with Stage IV disease) received induction chemotherapy. Fifty-eight patients (24 of whom had induction chemotherapy) were treated with the concomitant boost fractionation schedule. The median follow-up for surviving patients was 57 months. RESULTS: The overall actuarial 2- and 5-year survival rates were 78 and 68%, respectively. Forty-nine patients (40%) had disease recurrence. Thirty-three (27%) had local regional failures; 19 at the primary site only, 8 in the neck and 6 in both. Local failure occurred in 31% of patients staged T4 compared to 13% of T1-T3 (p = 0.007). Sixteen patients failed at distant sites alone. Among Stage IV patients the 5-year actuarial rates for patients who did and did not receive induction chemotherapy were as follows: overall survival: 68 vs. 56% (p = 0.02), freedom from relapse: 64 vs. 37% (p = 0.01), and local control: 86 vs. 56% (p = 0.009). The actuarial 5-year distant failure rate in patients with UNPC who were treated with induction chemotherapy and controlled in the primary and neck was 13%. In patients who did not receive chemotherapy, the actuarial 5-year local control rates for patients treated with concomitant boost or conventional fractionation were 66 and 67%, respectively. CONCLUSIONS: While not providing conclusive evidence, this single institution experience suggests that neoadjuvant chemotherapy for Stage IV NPC patients improves both survival and disease control. Recurrence within the irradiated volume was the most prevalent mode of failure and future studies will evaluate regimens to enhance local regional control.

Adolescent↗
PubMed1996

Dosimetric evaluation of lead and tungsten eye shields in electron beam treatment.

PURPOSE: The purpose of this study is to report that commercially available eye shields (designed for orthovoltage x-rays) are inadequate to protect the ocular structures from penetrating electrons for electron beam energies equal to or greater than 6 MeV. Therefore, a prototype medium size tungsten eye shield was designed and fabricated. The advantages of the tungsten eye shield over lead are discussed. METHODS AND MATERIALS: Electron beams (6-9 MeV) are often used to irradiate eyelid tumors to curative doses. Eye shields can be placed under the eyelids to protect the globe. Film and thermoluminescent dosimeters (TLDs) were used within a specially constructed polystyrene eye phantom to determine the effectiveness of various commercially available internal eye shields (designed for orthovoltage x-rays). The same procedures were used to evaluate a prototype medium size tungsten eye shield (2.8 mm thick), which was designed and fabricated for protection of the globe from penetrating electrons for electron beam energy equal to 9 MeV. A mini-TLD was used to measure the dose enhancement due to electrons backscattered off the tungsten eye shield, both with or without a dental acrylic coating that is required to reduce discomfort, permit sterilization of the shield, and reduce the dose contribution from backscattered electrons. RESULTS: Transmission of a 6 MeV electron beam through a 1.7 mm thick lead eye shield was found to be 50% on the surface (cornea) of the phantom and 27% at a depth of 6 mm (lens). The thickness of lead required to stop 6-9 MeV electron beams is impractical. In place of lead, a prototype medium size tungsten eye shield was made. For 6 to 9 MeV electrons, the doses measured on the surface (cornea) and at 6 mm (lens) and 21 mm (retina) depths were all less than 5% of the maximum dose of the open field (4 x 4 cm). Electrons backscattered off a tungsten eye shield without acrylic coating increased the lid dose from 85 to 123% at 6 MeV and 87 to 119% at 9 MeV. For the tungsten eye shield coated with 2-3 mm of dental acrylic, the lid dose was increased from 85 to 98.5% at 6 MeV and 86 to 106% at 9 MeV. CONCLUSION: Commercially available eye shields were evaluated and found to be clearly inadequate to protect the ocular structures for electron beam energies equal to or greater than 6 MeV. A tungsten eye shield has been found to provide adequate protection for electrons up to 9 MeV. The increase in lid dose due to electrons backscattered off the tungsten eye shield should be considered in the dose prescription. A minimum thickness of 2 mm dental acrylic on the beam entrance surface of the tungsten eye shield was found to reduce the backscattered electron effect to acceptable levels.

Equipment Design↗
PubMed1995

Local control of carcinoma of the tonsil by radiation therapy: an analysis of patterns of fractionation in nine institutions.

PURPOSE: To investigate the importance to outcome of treatment for squamous cell carcinomas of the tonsillar fossa, of dose per fraction, overall treatment duration, and total dose. METHODS AND MATERIALS: A collaborative retrospective study was undertaken in nine centers that used widely different dose-fractionation patterns for external beam radiation therapy. RESULTS: There were 676 eligible cases treated only with photon beams during the years 1976-1985. The probability of local control (of the tonsillar fossa primary) was influenced by both T-stage and N-stage. Significant treatment parameters were total dose and overall treatment duration, but not dose per fraction. Over the range of about 40 to 90% and for a constant overall treatment duration, local tumor control probability increased by nearly 2% for each 1 Gy increase in total dose. For a constant total dose there was a decrease in the probability of local control associated with prolongation of overall treatment duration, presumed to result from accelerated regrowth of surviving tumor clonogens during the course of treatment. If it is assumed that accelerated regrowth occurred at a constant rate and began within 9 days of the start of treatment, an average of 0.53 Gy extra dose per day's extension of treatment would be required to maintain a constant probability of local control. Correspondingly, the probability of local control from a constant dose would be lowered by an average of at least 1% for each day's extension of treatment duration. However, the data are slightly more consistent with an average delay of as long as 30 days before onset of accelerated repopulation, with a consequent increase to an average of 0.73 Gy per day for the value of the compensatory dose. The alpha/beta ratio for this tumor is high enough that the effect of fraction size on the probability of local control can be ignored; a precise estimate is not possible because the best value for beta was close to zero. After accounting for the significant variables studied (treatment time, T-stage, N-stage), the dose-response curves for tumor control were still shallow, suggesting that there are additional causes for heterogeneity of responses among these tumors. CONCLUSIONS: Total dose is important to treatment outcome: After accounting for other treatment variables, there is about a 2% per Gy increase in probability of tumor control over the ranges of control commonly achieved. Overall treatment duration is important. There is at least a 1% per day decrease in tumor control probability if delivery of a constant total dose is prolonged, requiring a compensatory increase in dose by 0.5-0.7 Gy per day to achieve a constant rate of tumor control. Fraction size is not, of itself, an important factor in the response of primary carcinoma of the tonsil. If a tumor has demonstrated a capacity for metastatic spread to lymph nodes, a higher total dose should be considered to achieve control rates at the primary site equivalent to those in node negative patients. Even after accounting for variables such as tumor stage, total dose, and overall treatment duration, there is sufficient heterogeneity in other undocumented determinants of tumor control to cause the tumor control probability curve to be a shallow function of dose.

Analysis of Variance↗
PubMed1995

Late normal tissue sequelae from radiation therapy for carcinoma of the tonsil: patterns of fractionation study of radiobiology.

PURPOSE: To evaluate the influence of dose fractionation and other factors on the development of late complications in mandibular bone, muscle, and mucosa of the oral cavity after external beam radiation therapy for carcinoma of the tonsil. METHODS AND MATERIALS: A retrospective analysis was made of the results in 676 patients treated with a spectrum of fractionation regimens in nine centers during the years 1976-1985. Only severe (Grades 3-4) late complications were analyzed. RESULTS: With more than 5 years follow-up, it was found that total dose was a factor for all three types of complications, but that in other respects, the radiobiology of late-(> 3 months) developing mucosal ulcerations was different from that for mandibular necrosis and muscle injury. Dose per fraction was a significant factor for bone and muscle (estimated alpha/beta values of 0.85 Gy and 3.1 Gy, respectively). By contrast, mucosa showed no influence on response from change in fraction size over the range of approximately 1.0-3.5 Gy. Complications in bone and muscle were not related to overall treatment duration, whereas there was a significant inverse relationship for mucosa breakdown. The rate of development of complications was fastest in mucosa and slowest in bone. The appearance of complications by 4 years after treatment was about 80% of those developing by 8 years in the mucosa, 66% in muscle, and about 50% in bone. The high alpha/beta ratio, inverse relationship with overall treatment duration, and faster development of mucosal complications suggests that they may develop as a consequence of earlier mucosal injury. As anticipated, adequate retrospective analysis of acute complications could not be made even when objective criteria such as weight loss, unplanned delays in completing treatment, or hospitalization during treatment were the measures. Field size was a significant factor for mandible complications, but not for muscle or mucosa. CONCLUSION: The radiobiological characteristics of bone and muscle were those characteristic of other late-responding tissues, whereas late sequelae in mucosa had radiobiological parameters similar to those for acute responses. Field size was a significant factor for bone complications but not for others.

Carcinoma, Squamous Cell↗
PubMed1995

Water bolus for electron irradiation of the ear canal.

PURPOSE: To demonstrate that water bolus in the external ear can decrease the dose inhomogeneity caused by auricular surface irregularities when the ear is in an electron-beam field. METHODS AND MATERIALS: Three-dimensional (3D) dose distributions with and without water bolus in the external ear were calculated for a representative patient. The electron dose calculations were made using the Hogstrom pencil beam algorithm as implemented in 3D by Starkschall. To demonstrate the use of water bolus in the ear clinically, the case of a patient with squamous carcinoma of the concha who was treated with electrons is presented. RESULTS: Water bolus markedly lessens the dose heterogeneity caused by the surface irregularities of the ear and the air in the external auditory canal. In the test case, the maximum dose was reduced by 25% using this technique. CONCLUSION: When the ear is in an electron beam field, warm water should be placed in the external auditory canal and concha. This maneuver may reduce the incidence of auricular complications that occur after electron-beam therapy.

Aged↗
PubMed1995

Base-of-tongue carcinoma: treatment results using concomitant boost radiotherapy.

PURPOSE: To evaluate the efficacy of accelerated fractionated radiotherapy using the concomitant boost schedule for patients with squamous cell carcinoma of the base of tongue. METHODS AND MATERIALS: Between September 1984 and July 1992, 54 patients with squamous carcinoma of the base of tongue were treated at The University of Texas M. D. Anderson Cancer Center using the concomitant boost schedule. The distribution of T and N stages was T1-4, T2-27, T3-22, and T4-1; N0-9, N1-11, N2-24, N3-7, and NX-3. American Joint Committee on Cancer (AJCC) stage groupings were II-6, III-14, and IV-34. Before radiation, nodal excision and neck dissection were done in 5 and 10 patients, respectively; 5 patients had neck dissections after radiotherapy. Standard on and off spinal cord fields were irradiated with 1.8 Gy fractions to 54 Gy given over 6 weeks. The boost was given concomitantly during the large field treatment as a second daily (1.5 Gy) fraction, with an interfraction interval of 4-6 h. The median dose to the primary tumor was 72 Gy (range, 66-74 Gy). The median treatment duration was 42 days (range, 39-48 days). Only three patients had treatment interrupted for more than one scheduled treatment day. RESULTS: The 5-year actuarial overall survival and disease-specific survival rates were 59 and 65%, respectively, with a median follow-up of 41 months. The 5-year actuarial locoregional control rate was 76%. The actuarial local control rates achieved with radiotherapy at 5 years for T1, T2, and T3 primary tumors were 100%, 96%, and 67%, respectively; including surgical salvage, the local control rate of T3 primary tumors was 70%. Six patients had regional failures, which in three patients occurred in conjunction with primary tumor recurrence. Twenty-six patients with regional adenopathy were treated with radiation alone to full dose and had a complete clinical response in the neck; no planned neck dissections were performed in these patients. Only 2 of these 26 patients had subsequent regional failures. The 5-year actuarial risk of distant metastases in patients whose disease was controlled locoregionally was 21%. Grade 3 or 4 confluent acute mucositis occurred in 94% of patients. However, late complications were limited to two cases of transient mandibular exposure and three cases of self-limited mucosal ulcerations. CONCLUSION: The concomitant boost fractionation schedule is a very effective regimen for this disease when appropriately selected patients are treated with meticulous technique. The therapeutic ratio is favorable, with a high rate of disease control and no persistent severe late complications. Patients whose neck disease responds completely to treatment with this schedule do not appear to need a planned neck dissection.

Adult↗
PubMed1995

Cutaneous angiosarcoma of the head and neck. A therapeutic dilemma.

BACKGROUND: Because of a tendency for diffuse, clinically undetectable local spread, cutaneous angiosarcoma is difficult to treat with surgery alone. Radiation is a rational treatment modality for this disease, because a wide region of dermis can be treated, whereas the underlying normal tissues are spared. METHODS: The authors retrospectively studied 14 patients with dermal angiosarcoma of the head and neck who were treated with electron-beam radiation from 1970 to 1989. Primary tumors were located in the scalp and forehead (11 patients) and in the upper face (3 patients). Eleven patients presented with multiple foci of disease. Three patients were treated with radiotherapy alone; the other 11 were treated with chemotherapy (10 patients) and/or surgery (7 patients). Surgical excisions were limited procedures for patients whose disease readily could be encompassed; total scalp resections were not performed. Patients were irradiated with a multiple-field electron-beam technique. Six patients presented postoperatively for radiotherapy with no macroscopic disease in the treatment field and were given a median dose of 60 Gy (range, 50-66 Gy) over a median of 40 days (range, 37-43 days). Eight patients were irradiated with clinically evident disease; doses ranged from 55 to 75 Gy over a median of 44 days (range, 33-66 days). RESULTS: Five of the six patients irradiated without clinically detectable disease were controlled in the treatment field, but only two are currently disease free. Of the eight patients irradiated with macroscopic tumor, initial disease recurrence occurred in the radiation field in two patients and at the radiation field margin in three patients. The actuarial 5-year control rates above the clavicles for patients irradiated with and without clinical disease were 24% and 40%, respectively (P = 0.03). The 5-year actuarial incidence of distant metastases for all patients was 63%. The 5-year actuarial survival rate for patients irradiated with and without clinical disease was 13% and 50%, respectively (P = .04). CONCLUSIONS: Radiation is an effective modality for treating local disease, especially when used after surgical resection of macroscopic tumor. Our current strategy is to resect clinically evident tumor in patients presenting with focal, limited disease, and to follow this resection with moderate dose, very wide-field radiation. The survival outcome for patients presenting with diffuse multifocal disease is bleak, but some patients can be controlled infield with radiation. There must be continued efforts to develop effective systemic therapy.

Aged↗
PubMed1995

The influence of positive margins and nerve invasion in adenoid cystic carcinoma of the head and neck treated with surgery and radiation.

PURPOSE: Surgery is the primary treatment for adenoid cystic carcinomas arising from major and minor salivary glands of the head and neck. However, local recurrence is frequent because of the infiltrative growth pattern and perineural spread associated with these tumors. At UTMDACC, we have had a longstanding policy of using postoperative radiotherapy to reduce the risk of local recurrence and to avoid the need for radical surgery; this 30-year retrospective study analyzes the results of this combined modality approach. METHODS AND MATERIALS: Between 1962 and 1991, 198 patients ages 13-82 years, with adenoid cystic carcinomas of the head and neck, received postoperative radiotherapy for known or suspected microscopic residual disease following surgery. Distribution of primary sites was: parotid: 30 patients; submandibular/sublingual: 41 patients; lacrimal: 5 patients; and minor salivary glands: 122 patients. Eighty-three patients (42%) had microscopic positive margins and an additional 55 (28%) had close (< or = 5 mm) or uncertain margins. One hundred thirty-six patients (69%) had perineural spread with invasion of a major (named) nerve in 55 patients (28%). Using radiation techniques appropriate to the primary site, a median dose of 60 Gy (range 50-69 Gy) was delivered to the tumor bed. Follow-up ranged from 5-341 months (median, 93 months). All surviving patients had a minimum of 2 years follow-up. RESULTS: Twenty-three patients (12%) had local recurrences with 5-, 10-, and 15-year actuarial local control rates of 95%, 86%, and 79%, respectively. Fifteen of the 83 patients (18%) with positive margins developed local recurrences, compared to 5 of 55 patients (9%) with close or uncertain margins, and 3 of 60 patients (5%) with negative margins (p = 0.02). Patients with and without a major (named) nerve involved had crude failure rates of 18% (10 out of 55) and 9% (13 out of 143), respectively (p = 0.02). There was a trend toward better local control with increasing dose. This was significant in patients with positive margins, in whom crude control rates were 40 and 88% for doses of < 56 Gy and > or = 56 Gy, respectively (p = 0.006). Actuarial 5-, 10-, and 15-year freedom from relapse rates were 68%, 52%, and 45%, respectively. Base of skull and neck failures were uncommon with or without elective treatment, developing in 2 and 3% of patients, respectively. Distant metastases were the most common type of disease recurrence, developing in 74 patients (37%) of whom 62 (31%) were disease-free at the primary site. CONCLUSIONS: Excellent local control rates were obtained in this population using surgery and postoperative radiotherapy and we recommend this combined approach for most patients with adenoid cystic carcinomas of the head and neck. Perineural invasion was an adverse prognostic factor only when a major (named) nerve was involved. Microscopic positive margins was also an adverse prognostic factor, but even when present, local control was achieved in over 80% of our patients. We recommend a dose of 60 Gy to the tumor bed, supplemented to 66 Gy for patients with positive margins. Despite effective local therapy, one-third of patients fail systemically, and good treatment to address this problem is lacking.

Actuarial Analysis↗