Search PubMed⌕ Search

Biomedical subjects

L R Coia

Publications and source records attributed to L R Coia.

At least 73 records · Page 4Linked to original sources
PubMed1992

Recent patterns of growth in radiation therapy facilities in the United States: a patterns of care study report.

The Patterns of Care Study conducted its seventh survey of radiation oncology facilities with megavoltage equipment. The aims were to identify the basic structural characteristics of the radiation oncology specialty, to allow comparison with previous surveys, to identify trends in the patterns of equipment and personnel usage, and to measure the capabilities of facilities to deliver modern radiotherapy. All radiation oncology facilities in the United States and Puerto Rico were surveyed. Multiple mailings and calls yielded identification of and responses from virtually all facilities doing megavoltage radiotherapy. The survey collected information on equipment, patient load, personnel, and types of procedures performed. The complete census was reviewed, summarized, and compared to previous surveys. Results for 1990 showed 1321 facilities, (938 hospital based, 350 freestanding, 33 federal), 492120 new patients, and 2397 treatment machines (1893 linear accelerators or betatrons and 504 cobalt machines). The number of facilities and total machines increased rapidly with most of the increase in facilities occurring in the freestanding category. The number of cobalt units declined, while the number of linear accelerators increased. The results also showed that 6% of facilities did not have the capability of simulating patients and 7% of facilities did not have treatment planning capability. Of all facilities 9% reported doing intraoperative radiation therapy and 18% doing hyperthermia. For recent years in the specialty of radiation oncology the number of facilities and treatment machines increased at a more rapid rate than the number of new patients.

Health Facilities↗
PubMed1992

A report of the consensus workshop panel on the treatment of brain metastases.

The consensus workshop on management of brain metastases focused on several broad issues concerning the patient with brain metastases. These issues included: What are the goals of treatment? Who should not be treated with radiation? What are the optimal treatment regimens? What are the areas of controversy where future investigations may be useful? The brain consensus panel attempted to develop guidelines for radiation oncologists through use of a decision tree format. Existing data to support management decisions, particularly those regarding radiation treatment, were reviewed. Data regarding cost of treatment as well as data regarding explicit quality of life measures were felt to be very important but were largely not available and therefore played little scientific role in the guideline development. Areas where controversy existed and where consensus could not be reached were identified.

Brain Neoplasms↗
PubMed1992

The role of radiation therapy in the treatment of brain metastases.

Whole brain irradiation is the most effective means for treating the patient with brain metastases with symptom relief occurring in 70 to 90% of patients. However, 25-50% of patients with brain metastases will die due to eventual failure in the brain and therefore entry of patients into investigative trials is essential for continued progress in the management of this problem. For the patient who is not part of an investigative trial, short courses of radiation of 20 Gy in 1 week or 30 Gy in 2 weeks are generally as effective as more prolonged courses and even shorter courses of treatment could be considered, particularly for the patient with an estimated survival of only 5-6 weeks. The importance of the treatment of brain metastases on the practice of radiation oncology is significant and comparable to other major cancers treated with radiation. It is critical that radiation oncologists can apply this treatment modality in a cost effective manner with careful consideration for the patients' quality of life.

Brain Neoplasms↗
PubMed1992

Factors affecting treatment patterns of radiation oncologists in the United States in the palliative treatment of cancer.

A questionnaire was sent to 488 radiation oncologists in the United States and 268 replied. Each was given a brief account of three hypothetical patients (one with brain metastases, one with locally advanced lung cancer and one with bone metastases) and asked how they would approach the problems posed. Younger radiation oncologists (less than 46 years) treated patients with brain metastases with a smaller number of fractions and were more likely to view the case of locally advanced lung cancer as palliative. The aim of the radiation oncologist was related to the treatment pattern chosen, with the aim to extend life frequently related to higher total dose and number of fractions. When the amount of private funding was compared with dose, number of treatments, and whether the case was called palliative or not, no relationship was found.

Age Factors↗
PubMed1991

Numerical scoring of treatment plans.

This is a report on numerical scoring techniques developed for the evaluation of treatment plans as part of a four-institution study of the role of 3-D planning in high energy external beam photon therapy. A formal evaluation process was developed in which plans were assessed by a clinician who displayed dose distributions in transverse, sagittal, coronal, and arbitrary oblique planes, viewed dose-volume histograms which summarized dose distributions to target volumes and the normal tissues of interest, and reviewed dose statistics which characterized the volume dose distribution for each plan. In addition, tumor control probabilities were calculated for each biological target volume and normal tissue complication probabilities were calculated for each normal tissue defined in the agreed-upon protocols. To score a plan, the physician assigned a score for each normal tissue to reflect possible complications; for each target volume two separate scores were assigned, one representing the adequacy of tumor coverage, the second the likelihood of a complication. After scoring each target and normal tissue individually, two summary scores were given, one for target coverage, the second reflecting the impact on all normal tissues. Finally, each plan was given an overall rating (which could include a downgrading of the plan if the treatment was judged to be overly complex).

Humans↗
PubMed1991

Pretreatment and treatment factors associated with improved outcome in squamous cell carcinoma of the uterine cervix: a final report of the 1973 and 1978 patterns of care studies.

The Patterns of Care Study (PCS) conducted two national surveys of patients treated in 1973 and 1978 for squamous cell cancer of the uterine cervix. In addition, a survey of patients treated in 1973 from selected large facilities was conducted to establish outcome with "optimal" radiotherapy. The large facility survey consistently reported improved outcome compared to both national average surveys when analyzed by stage and other significant pretreatment factors. That improved outcome was associated with the paracentral (PCS point A) dose and the use of intracavitary irradiation. In this study, we report the pretreatment and treatment factors associated with improved outcome in squamous cell carcinoma of the uterine cervix by analysis of the 1973 and 1978 PCS data. Pretreatment factors associated with improved pelvic control in multivariate analysis include higher Karnofsky Performance Status (KPS) (Stage I and II), older age (Stage I and II), unilateral parametrial involvement (Stage IIB), and unilateral sidewall involvement (Stage III). The only treatment factor associated with improved pelvic control in multivariate analysis is the use of intracavitary irradiation. However, a dose response for infield pelvic control was demonstrated only in Stage III cervix cancer with the highest rate of pelvic control with paracentral (PCS point A) dose greater than 8500 cGy. Multivariate analysis revealed that unilateral parametrial involvement for Stage IIB and unilateral sidewall involvement for Stage III are significant positive prognostic factors with respect to survival after treatment with radiotherapy. No FIGO substage significantly affected survival after radiotherapy. Although FIGO staging is the single most important pretreatment prognostic factor with respect to survival and infield pelvic failure, FIGO substaging deserves reappraisal and further refinement. Major complications were seen in only 9.5% of patients treated with radiotherapy and were stage but not survey related. There is a significant relationship between PCS point A dose and complications with the highest rate of complications for PCS point A dose greater than 8500 cGy. A significant relationship between lateral (external iliac lymph nodes or PCS point P) dose and major complications is also found, and doses greater than 5000 cGy are associated with a significant increase in complications. The PCS has established two sequential national benchmarks of treatment outcome for squamous cell carcinoma of the uterine cervix treated with radiotherapy with respect to survival, infield pelvic control, and complications.(ABSTRACT TRUNCATED AT 400 WORDS)

Age Factors↗
PubMed1991

A new device for interstitial 125Iodine seed implantation.

A new device for interstitial implantation of I125 seeds is presented. The technical details and function of the system are described and compared with well-known commercial systems. Its unique design allows for simple, fast, and safe treatment of most tumor sites including stereotactic implantation of brain. Radiation measurements indicate low exposure to both patients and personnel during implantation.

Brachytherapy↗
PubMed1991

Long-term results of infusional 5-FU, mitomycin-C and radiation as primary management of esophageal carcinoma.

An analysis of the results of 90 patients with esophageal cancer treated prospectively with combined chemotherapy and radiation without surgery and with a median follow-up of 45 months is presented. Fifty-seven patients with Stage I or II disease received definitive treatment consisting of 6,000 cGy in 6 to 7 weeks and 5-FU (1,000 mg/m2/24 hr) as a continuous intravenous (IV) infusion for 96 hours, starting on days 2 and 29. Mitomycin C (10 mg/m2) was administered as a bolus injection on day 2. Thirty-three patients received palliative treatment (5,000 cGy plus above chemotherapy) for Stage III, IV, or otherwise advanced disease (extraesophageal spread, distant metastases, multiple primary tumors). Follow-up ranged from 1 month to 96 months. Overall median survival of Stage I and II patients was 18 months with 3- and 5-year actuarial survival of 29% and 18%, respectively, while the median disease specific survival was 20 months with an actuarial disease specific survival of 41% and 30% at 3 and 5 years, respectively. A multivariate analysis of sex, histology, tumor location, and tumor size on survival revealed that the effect of stage was highly significant (Stage I versus II, 73% versus 33% at 3 years, p = .01), whereas the effect of sex approached significance (females versus males, 57% versus 34% at 3 years, p = less than .1). The actuarially determined local relapse-free rate for Stage I and II patients at both 3 and 5 years was 70%. Multivariate analysis again indicated stage to be highly significant (Stage I versus II, 100% versus 60% at 3 years, p = less than .01), whereas sex approached significance (female versus male, 75% versus 66% at 3 years, p = .07). The pattern of failure may be altered with this treatment regimen from local to one dominated by distant metastases. Of 29 patients who have failed, 14 (48%) had any component of local failure, whereas 21 (72%) had a distant failure as a component of failure. The median survival of patients with Stage III or IV disease was 9 months and 7 months, respectively. Palliation in this group of patients with advanced disease was good as 77% were rendered free of dysphagia post-treatment, and 60% were without dysphagia until death with a median dysphagia-free duration of 5 months. Severe toxicities were uncommon and nearly all were transient. Eleven of 90 patients (12.2%) had severe acute toxicities, whereas only 3 patients (3.3%) developed significant late treatment-related complications requiring hospitalization for management.

Adenocarcinoma↗
PubMed1991

Prognostic factors in patients with early stage non-Hodgkin's lymphomas of the head and neck treated with definitive irradiation.

Between 1974 and 1989, 58 patients with clinical Stages I and II non-Hodgkin's lymphomas of the head and neck were treated with radiation at the Fox Chase Cancer Center. Forty-one treated with radiotherapy alone form the basis for this retrospective analysis of outcome and prognostic factors. With a mean radiation dose of 4400 cGy, the 5-year actuarial local control rate is 92%. Only one patient failed within an irradiated field. The 5-year actuarial survival and relapse-free survival rates are 85% and 54%, respectively. In a univariate analysis, poor survival was significantly correlated with involvement of Waldeyer's ring, postoperative tumor size greater than 3 cm, and greater than two involved lymph nodes and extranodal sites (p less than 0.02). No such correlations were seen for stage, histologic grade, the presence of extranodal disease, or any of the other parameters that were examined. Relapse free survival was significantly correlated only with the total of the number of involved nodes and extranodal sites. Patients with one or two involved nodes and sites had a 68% chance of remaining disease-free at 5 years compared to 0% for patients with greater than two (p = .02). Again, significant trends were not seen for the other parameters analyzed. These data demonstrate excellent local control, survival, and relapse-free survival using radiation alone with doses of 3000-5000 cGy. In our group of clinically staged patients preselected for treatment with radiation alone, the total of the number of involved nodes and extranodal sites, involvement of Waldeyer's ring, and tumor size after resection correlated strongly with relapse-free survival and overall survival. In patients with early stage non-Hodgkin's lymphomas of the head and neck, initial management with external beam radiotherapy should be considered in particular for those with one or two involved nodes and extranodal sites that are less than 3 cm following resection and that do not involve Waldeyer's ring.

Adult↗
PubMed1991

Comparison of 1 vs 2 or more intracavitary brachytherapy applications in the management of carcinoma of the cervix, with irradiation alone.

Four hundred ninety-eight patients treated in the USA in 1978 for cancer of the cervix by external beam and intracavitary irradiation have been studied to determine the effect of using a single intracavitary (IC) application versus more than one. Most of the patients (46%) underwent intracavitary (IC) treatment after external radiation therapy (RT), 40% during external RT, and 14% prior to external RT. Five-year actuarial survival for all stages was 66% for greater than or equal to 2 applications versus 59% for 1 application, p less than .01. When survival was analyzed by stage, there was a trend toward improved survival with greater than or equal to 2 applications in Stage II (p .10). The rate of infield recurrence for all stages was higher in the 1 IC group (30% vs 17%, p less than .01). These were more frequent in the 1 IC group (53% vs 34%, p less than .05), in Stage III patients, but no significant difference was noted in the other stages. Distant metastases were more frequent in the 1 IC group (19% vs 11%, p .01). The incidence of major complications was the same in both groups. An analysis of patient characteristics and other variables that would explain the difference in results revealed that older patients (p .03), worse Karnofsky (p .056), and more parametrial involvement (p less than .01) accrued more in the 1 IC group. Higher paracentral point doses were administered when greater than or equal to 2 IC applications were used (p less than 0.01); this group also received higher bladder and rectal doses and lower whole pelvic doses. The use of two or more intracavitary insertions affords an opportunity to administer higher paracentral point doses, which appear to be related to higher pelvic tumor control, lower rate of distant metastasis, and better survival.

Adult↗
PubMed1991

Tumor and treatment factors improving outcome in stage III-B cervix cancer.

This report reviews 271 patients with Stage III-B squamous cell cancer of the uterine cervix from three national surveys conducted by the Patterns of Care Study. A progressive increase in local control and survival is seen among the three surveys which parallels a progressive increase in paracentral (point A) dose and use of intracavitary treatment. Multivariate analysis reveals extent of pelvic disease (unilateral sidewall vs. bilateral sidewall vs. lower 1/3 vagina) and use of intracavitary treatment to be the only significant tumor and treatment factors associated with local control and survival. With aggressive radiotherapy, local control rates exceeding 65% and survival of 50% at 4 years can be anticipated at the expense of a small increase in complications.

Aged↗
PubMed1991

Significance of prone positioning in planning treatment for esophageal cancer.

The treatment of esophageal cancer is made difficult by the close proximity of the esophagus to the spinal cord and the requirement to treat the esophageal target volume to doses greater than or equal to 60 Gy while limiting the spinal cord dose to less than or equal to 46 Gy. By placing the patient in the prone position, the esophagus can be displaced away from the spinal cord. We explored the results of this commonly used technique on 16 patients who have undergone simulation in both supine and prone positions. Both AP and lateral orthogonal radiographs were obtained in both positions. The distance between contrast material in the esophagus and spinal cord was noted in at least four transverse planes through the thoracic esophagus on each of the 16 patients. These four transverse planes were located at 3 cm above the carina, at the carina, 3 cm below the carina and 6 cm below the carina. The mean displacement (+/- 1 SD) of the esophagus away from the spinal cord when the patient was in the prone position compared to supine at each of these levels was 1.3 (+/- 0.8) cm, 1.8 (+/- 0.9) cm, 1.8 (+/- 1.0) cm, and 1.9 (+/- 1.1) cm. The range of displacement for all 64 displacement determinations was 0 to 4.2 cm with a mean of 1.7 cm. To evaluate further the consequences of prone positioning on treatment planning and doses received to target volumes and critical structures, we performed 3-dimensional treatment planning with a patient in both prone and supine positions. The requirements were to achieve a tumor volume dose of 60 Gy while keeping the spinal cord dose below 46 Gy. Two types of conventional treatment plans were examined in prone and supine positions. A 6-field plan consisted of delivery of 40 Gy through a large 3-field beam arrangement followed by delivery of 20 Gy through a similar 3-field cone down. An 8-field plan involved the delivery of 30 Gy through AP/PA beams followed by a 3-field beam arrangement to 40 Gy and a subsequent 3-field cone-down for the final 20 Gy. Comparison of dose volume histograms revealed that the 6-field plan spared relatively more heart whereas the 8-field plan spared relatively more lung. Regarding the primary consideration of coverage of target volume with avoidance of spinal cord, prone positioning was superior to supine positioning whether 6- or 8-field arrangements were used.

Esophageal Neoplasms↗
PubMed1991

The effect of local-regional control on distant metastatic dissemination in carcinoma of the head and neck: results of an analysis from the RTOG head and neck database.

A retrospective analysis of the effect of local control on the development of distant metastases was performed in 2648 patients with carcinoma of the head and neck selected from the RTOG database. The 5-year time-adjusted incidence of distant metastases was 21% for patients who were in local-regional control at 6 months after the start of treatment, compared to 38% for local-regional failure patients (p less than 0.001). The incidence of distant metastases detected between the interval of 6 months to 2.5 years after treatment was significantly increased in patients with tumors of the oral cavity, oropharynx, supraglottic larynx, and glottis who developed local-regional failure within this time period, compared to those who remained locally controlled (19% distant metastases for local-regional failure vs 7% for local-regional control (p less than 0.001)). In contrast, there as no difference in the incidence of distant metastases in patients with carcinoma of the nasopharynx or hypopharynx regardless of the local-regional disease status. A Cox proportional hazards regression analysis demonstrated that local-regional control was the most significant variable affecting the development of distant metastases, followed by tumor site, N-stage, and T-stage. For all tumor sites, except for the hypopharynx and nasopharynx, improvements in local-regional control are likely to improve survival. Tumors of the hypopharynx and nasopharynx have a higher probability of micro-metastatic dissemination at the time of initial diagnosis, and until effective methods to treat disseminated disease are developed, the effect of local control on survival will not be readily discerned.

Carcinoma, Squamous Cell↗
PubMed1990

Randomized trials of adjuvant radiation therapy for rectal carcinoma: a review.

An estimated 44,000 cases of rectal carcinoma arise annually in the United States. The traditional management of this disease has been surgery alone, but advances in adjuvant therapy offer potential for improvement of local control, disease-free survival, and survival. In the last two decades, many multicenter randomized trials of adjuvant preoperative and postoperative radiation therapy for rectal carcinoma have been reported. The design and results of these trials are critically reviewed. Results from preoperative trials have been conflicting, reflecting the heterogeneity of the trial designs. Large postoperative adjuvant trials have been reported recently. The combined analysis of local recurrence data from the mature, published trials indicates that radiation therapy results in improved local control (P = 0.02), an important concern in rectal carcinoma as local recurrences present vexing and painful clinical problems often refractory to conventional management. These trials also have shown that radiation therapy can contribute to improved survival in the combined modality setting. Improvements in the clinical outcome of rectal cancer should be possible with appropriate adjuvant therapy. The success of combined modality adjuvant therapy for rectal carcinoma may serve as a model to aid in the design of therapeutic regimens for other solid tumors.

Combined Modality Therapy↗
PubMed1990

Adenocarcinoma of the esophagus and esophago-gastric junction: the effects of single and combined modalities on the survival and patterns of failure following treatment.

One hundred sixty-five patients with localized adenocarcinomas of the esophagus or esophago-gastric (EG) junction were treated with surgery alone, radiation therapy alone, chemotherapy alone, surgery followed by post-operative radiation therapy, chemotherapy, or chemosensitized radiation therapy, and chemosensitized radiation therapy alone. Patients were retrospectively evaluated for survival, control of tumor within the mediastinum, post-operative swallowing function, patterns of failure, and treatment-related morbidity. Follow-up of survivors ranges from 9-88 months (median 23 months). Chemotherapy and radiation therapy as single modalities were associated with a recurrence rate of 100%. Combined modality therapy significantly reduced the risk of local recurrence in all patient groups. Chemosensitized radiation therapy alone reduced the local recurrence rate to 48%, and surgery followed by radiation therapy reduced the local failure rate to 24%. When chemotherapy or chemosensitization was added to surgery plus radiation, the risk was further reduced to 15%. The use of combined modality therapy was also found to extend the survival of patients without excessive toxicity. Median survival was shortest among the group treated with radiation alone (5 months) and intermediate among patients following chemosensitized radiation alone (10 months) or complete surgical resection alone (15 months). Patients treated with all three modalities had the longest median survival (21 months). Based on this experience, the optimum treatment of these patients appears to include aggressive attempts at surgical resection with chemosensitized radiation therapy. Excellent palliation can also be achieved in unresectable patients with chemosensitized radiation therapy with a smaller chance for long term survival.

Adenocarcinoma↗