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L Coia

Publications and source records attributed to L Coia.

28 records · Page 2Linked to original sources
PubMed1991

Three-dimensional photon treatment planning for Hodgkin's disease.

A multi-institutional study was undertaken using computerized planning systems to develop three-dimensional (3-D) radiotherapy plans for Hodgkin's disease (H.D.). Two patients, the first afflicted with bulky stage II disease and another one with early stage I H.D., were studied. Three main categories of plan were produced for each patient: a) a traditional plan which modelled a conventional mantle treatment on the 3-D system, b) a 3-D standard plan where anterior and posterior fields were designed to cover 3-D target volumes, and c) a 3-D unconstrained plan where innovational techniques were employed. Three-dimensional planning provides information about the dose distribution throughout the large volume irradiated in patients with H.D. that is not available with conventional mantle planning. The use of 3-D techniques resulted in improved tumor coverage, but by allowing for uncertainties such as motion, the doses to normal tissues tended to be higher. The use of unorthodox beam arrangements introduced added complexities, and further increased the lung doses. The most even dose distributions were obtained by incorporating compensating filters into anterior fields. Clinicians showed wide variations in their assessment of the plans, possible reasons for which are addressed in this paper. In addition, calculated probabilities from models of tumor control and normal tissue damage are also presented.

Hodgkin Disease↗
PubMed1991

Three-dimensional treatment planning for lung cancer.

The experience of four institutions involved in a three-dimensional treatment planning contract (NCI) for lung cancer is described. It was found that three-dimensional treatment planning has a significant potential for optimization of treatment plans for radiotherapy of lung cancer both for tumor coverage and sparing of critical normal tissues within the complex anatomy of the human thorax. Evaluation tools, such as dose-volume histograms, and three-dimensional isodose displays, such as multiple plane views, surface dose displays, etc., were found to be extremely valuable in evaluation and comparison of these complex plans. It is anticipated that with further developments in three-dimensional simulation and treatment delivery systems, major progress towards uncomplicated local regional control of lung cancer may be forthcoming.

Humans↗
PubMed1991

ASTRO plenary: interfraction interval is a major determinant of late effects, with hyperfractionated radiation therapy of carcinomas of upper respiratory and digestive tracts: results from Radiation Therapy Oncology Group protocol 8313.

A prospective, randomized, multi-institutional, Phase I(LE)/II trial of HFX was conducted by the RTOG between 1983 and 1987. Patients with histologically proven, inoperable squamous cell carcinoma of the upper respiratory and digestive tracts stratified by site, nodal status, and performance status, were assigned to one of three arms, were assigned to one of three arms, 67.2 Gy, 72.0 Gy, or 76.8 Gy. Fractions of 1.2 Gy were given twice daily, 5 days per week: intervals of 4 to 8 hours were permitted between fractions. After acceptable rates of acute normal tissue effects were found, the randomization was changed to evaluate a new higher total dose, 81.6 Gy. Of 479 patients entered, 447 were analyzed, 63 on 67.2 Gy, 129 on 72.0 Gy, 117 on 76.8 Gy, and 138 on 81.6 Gy. The treatment arms were well balanced with respect to pretreatment characteristics. Acute reactions consisted almost entirely of pseudomembranous inflammation. "Severe" (Grade 3) acute reactions were reported in 33% to 41% and grade 4 reactions were found in 0 to 3% of patients, with no differences in frequencies among the four arms. Toxicities that developed or persisted beyond 90 days after the first treatment (408 patients evaluable greater than 90 days) did not differ among arms: grade 3+ reactions occurred in 10% to 14%, and grade 4+ effects (necroses) were reported in 5% at 67.2 Gy, 3% at 72.0 Gy, 7% at 76.8 Gy, and 2% at 81.6 Gy. Grade 3+ acute reactions occurred in 40% of patients when the interfraction interval was less than or equal to 4.5 hours versus 31% with greater than 4.5 hours (p = .03). Interfraction intervals less than or equal to 4.5 hours were associated with higher frequencies of grade 4+ late effects in all four arms, 8% of 197 patients with less than or equal to 4.5 hours versus 1% of 211 patients with greater than 4.5 hours. Estimates of late toxicity at 1, 2, and 3 years were 5.5%, 9.8%, and 15.4% with intervals less than or equal to 4.5 hours, versus 1.7% at all three periods for greater than 4.5 hours (p = .006). Local-regional control at 2 years was 25% for the assigned dose of 67.2 Gy compared to 43% to 45% for the three higher doses (p = .01), but a similar comparison for survival showed no significant difference (p = .35). There was no evidence for an effect of interfraction interval on either local-regional control (p = .38) or survival (p = .28).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1990

The Patterns of Care Outcome Study for cancer of the uterine cervix. Results of the Second National Practice Survey.

This report summarizes the outcome results of the Patterns of Care Study (PCS) of cancer of the uterine cervix from 565 patients treated in 1978. The 5-year survival with no evidence of disease was: Stage I, 74%; Stage II, 56%; and Stage III, 33%. The 5-year local in-field failure rate was: Stage I, 12%, Stage II, 27%; and Stage III, 51%. Extent of parametrial involvement, unilateral versus bilateral, may be important in determining survival and local failure. The four-year actuarial survival was 58% for unilateral involvement versus 47% for bilateral (P = 0.06), and the local failure rate was 32% for unilateral versus 45% for bilateral (P less than 0.05). When analyzed by stage, patients with Stage IIb disease with unilateral parametrial involvement showed a trend toward improved survival and decreased local failure compared with those with bilateral Stage IIb cancers (P = 0.1). The use of intracavitary irradiation significantly improved survival and reduced local failures. Furthermore, the number of intracavitary applications was important. When two or more intracavitary applications were used compared with one application, local in-field failure was significantly reduced, 29% versus 17% at 4 years (P less than 0.001), and four-year survival was improved, 60% versus 73% (P = 0.01). The four-year actuarial rate of major complications depended on the stage: Stage I, 8%; Stage II, 15%; and Stage III, 13%. There was a statistically significant increase in major complications in patients undergoing laparotomy for staging versus no laparotomy 23% versus 11% at 4 years (P less than or equal to 0.01) and a trend toward increased major complications in patients who were thin or had prior abdominal surgery. This study confirmed the stage-dependent outcome of treatment of cancer of the uterine cervix with radiation and indicated that further division of Stage IIb to indicate prognostic significance of unilateral or bilateral parametrial involvement may be warranted. This study also confirmed the importance of intracavitary radiation in optimizing control established by the 1973 PCS. It further suggests that where possible, two intracavitary insertions may yield better results than one insertion.

Brachytherapy↗
PubMed1986

Spinal cord protection during radiation therapy.

Treating intrathoracic malignancies to high doses, particularly those of lung and esophagus, requires limiting the radiation dose delivered to the spinal cord. Several factors are important in determining the cord dose. These are: The distance from the block or collimator edge to the cord, the variation of dose with distance from the block or collimator edge and, the expected variation of this distance for clinical set-up from day-to-day. When treating with an oblique beam, the position of the cord may be difficult to identify. A technique for localizing the spinal cord on a simulator film at an arbitrary gantry angle is presented. The technique requires determination of distances from the central axis of the beam to the medial aspect of the pedicle and posterior vertebral body. These can readily be obtained from measurements on orthogonal, AP/PA and lateral isocentric simulator radiographs. A mathematical transformation is applied to determine the corresponding cord locations on the oblique radiographs for any arbitrary gantry angle. The accuracy of cord localization was within 2-3 mm with a precision of 2 mm for five physicians who used this technique. The beam edge characteristics for 60Co, 6 MV, and 10 MV teletherapy unit were measured for various depths and field sizes. For the 6 and 10 MV units, the beam penumbra is nearly independent of the field size, depth and field defining devices (inner and outer collimator jaws, trimmer bars, and shielding blocks). Because the beam penumbra is dependent on the design of the linear accelerator, its measurement should be made individually for each linear accelerator. Our preliminary data on patient positioning uncertainty did not exceed the 6-8 mm limit documented in the literature.

Humans↗
PubMed1983

Left varicocele at puberty.

A study was made of 160 cases of left varicocele treated during 1979-1980; there were 35 patients under sixteen years old. Also 74.3 per cent of patients already had mono- or bilateral testicular hypotrophy. Testicular biopsy revealed 90 per cent had histologic lesions of varying nature and degree. We believe varicocele formation is related to physiologic changes during puberty. These data suggest that early recognition of varicocele and its correction before the appearance of irreversible testicular lesions may prevent male sterility.

Adolescent↗
PubMed1979

Histological lesions in the testis of infertile men with varicocele.

Varicocele frequently causes male infertility and histological lesions at the contralateral testis. The most frequent lesions found in this study included maturation arrest in the spermatidic phase, cellular and acellular thickening of the tubular wall, and degeneration of the Leydig cells. These lesions were typical of varicocele and their simultaneous presence suggests that scrotal temperature and modified endocrine secretion of the interstitial testis play a role in the pathogenesis of this type of infertility.

Humans↗
PubMedDate not supplied

CT staging of esophageal carcinoma in patients treated by primary radiation therapy and chemotherapy.

Primary radiation therapy with concurrent chemotherapy is under study as definitive and palliative therapy for patients with esophageal carcinoma. To evaluate the correlation between CT staging and outcome, we retrospectively reviewed the CT scans of 48 patients treated with primary radiation therapy and concurrent chemotherapy and correlated CT staging with disease-free survival, overall survival, and site of relapse. Excluding one patient who was understaged and six patients who died of problems unrelated to esophageal carcinoma, mean survival of CT stage I, II, and III patients was 14.7, 21.3, and 5.2 months, respectively. When the CT stage is modified by the presence of nodal involvement on CT, the mean survival of stage IIn and IIIn (nodes greater than 1.5 cm in diameter) and stage IV patients (distant metastases) was 16.4, 19.2, and 10.6 months, respectively. Despite thickening of the esophageal wall greater than 3.0 cm in five patients with stage IIn cancer, mean survival was still 19.2 months. Patients with pericardial effusion had the worst survival of only 4.3 months. Stage II patients had a significantly longer (p less than 0.05) disease-free period than all other groups and the difference between stage II and III patients was highly significant (p less than 0.01). Stage II patients were also more likely to be disease-free at the time of death or last follow-up (p less than 0.05). Computed tomographic staging of esophageal carcinoma is useful in radiation therapy treatment planning and predicting outcome of patients managed with a nonsurgical technique of concurrent radiation and chemotherapy.

Adult↗