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F J Bova

Publications and source records attributed to F J Bova.

15 recordsLinked to original sources
PubMed1992

Radiation therapy for skin cancer near the eye: kilovoltage x-rays versus electrons.

When skin cancer near the eye is irradiated, a corneal shield is placed between the lids and globe to protect ocular structures. The effectiveness of the shield was evaluated with 250 kVp x-ray and 6-20 MeV electron beams. To simulate the clinical situation, a face phantom was constructed out of solid pieces of water-equivalent epoxy. In the region of the eye the phantom was milled to the exact contour of a human face. The phantom was used to reconstruct the setup that had been used to treat a patient with a 1-cm basal cell carcinoma of the mid portion of the lower lid. A medium-sized corneal shield (2-mm-thick lead plated with 0.1 mm gold) was placed on the eye portion of the phantom. A contoured lead (6 mm thick) face mask was placed on the surface of the phantom to define a 3-cm diameter radiation field that included only the inferior hemisphere of the shield. The doses that the cornea, lens, and retina would receive beneath the midpoint of the inferior hemisphere of the shield were measured using thermoluminescent and film dosimetry. With 6 to 8 MeV electrons, the corneal dose was 2 to 4 times higher than with 250 kVp x-rays. Corneal and lens doses rose rapidly with increasing electron beam energy such that with greater than 8 MeV the shield would provide relatively poor ocular protection. A scanning ion chamber and film dosimetry were used to determine the isodose profiles of 250 kVp x-ray and 6 MeV electron beams for a 3-cm diameter field collimated on the surface. With 250 kVp x-rays the 95% isodose area was 32% wider than with 6 MeV electrons. The ease of shielding and the ability to minimize field size argue in favor of kilovoltage x-rays for early-stage skin cancer near the eye.

Costs and Cost Analysis↗
PubMed1992

Pulmonary function tests after whole-lung irradiation and doxorubicin in patients with osteogenic sarcoma.

PURPOSE: Because of the scarcity of information regarding long-term follow-up of pulmonary function after whole-lung irradiation, a prospective study was started at the University of Florida in 1979 to evaluate pulmonary function after treatment with whole-lung irradiation and doxorubicin in patients with osteogenic sarcoma. PATIENTS AND METHODS: Between 1979 and 1984, 57 osteogenic sarcoma patients with no evidence of metastatic disease at diagnosis received adjuvant therapy consisting of whole-lung irradiation (with the heart shielded) followed by Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH). The whole-lung irradiation schema was 1,600 cGy in 10 fractions with 8-MV x-rays via anterior and posterior fields. This was followed by five cycles of Adriamycin for a total dose of 450 mg/m2. Pulmonary function tests (PFTs) consisting of spirometry, lung volumes, and diffusing capacity were obtained before the whole-lung irradiation, at 6 and 12 months after irradiation, and at yearly intervals thereafter. RESULTS: At the time of analysis, 28 of the 57 patients were available for study, with a mean follow-up of 42 months (range, 6 to 77 months). Follow-up pulmonary function testing revealed decreased forced vital capacity (FVC) and forced expiratory volume at 1 second (FEV1) during the first 6 to 12 months after whole-lung irradiation. These values returned to baseline during the second-year posttherapy and remained at baseline throughout the remainder of the follow-up period. Changes in lung volumes demonstrated a similar early trend, with significant decreases in total lung capacity (TLC) and functional residual capacity (FRC) at 6 to 12 months. These changes, however, did not improve significantly during the remainder of the follow-up period. Diffusing capacity of the lungs for carbon monoxide (DLCO) also reached a nadir at 6 to 12 months after whole-lung irradiation, with resolution by 2 years and maintenance of at least baseline values for the remainder of the follow-up period. CONCLUSIONS: Treatment with whole-lung irradiation and Adriamycin, as given in this study, caused no significant sequelae, as demonstrated by pulmonary function testing during the mean follow-up period of 42 months, although a mild, transient restrictive ventilatory defect occurred at 6 to 12 months after treatment.

Adolescent↗
PubMed1992

Limitations of angiographic target localization in planning radiosurgical treatment.

Planning radiosurgical treatment for cerebral arteriovenous malformations requires accurate definition of the true tridimensional size and shape of the nidus. Over- or underestimation of these parameters may result in undue irradiation of normal brain tissue or suboptimal irradiation coverage of the malformation leading to treatment failure. Angiography is not an ideal database for radiosurgery of arteriovenous malformations. Its shortcomings include planar representation of a tridimensional volume and simultaneous visualization of feeding arteries and draining veins overlapping with the nidus and obscuring its outline. Two illustrative clinical cases of these angiographic inadequacies are presented. Stereotactic, contrast-enhanced computed tomography may provide, in selected cases, better spatial definition of the nidus and superior anatomic detail for the final design of the radiosurgical isodose distribution.

Adult↗
PubMed1992

Linear accelerator radiosurgery for arteriovenous malformations.

Between May, 1988, and August, 1991, 80 patients with arteriovenous malformations (AVM's) were treated radiosurgically at the University of Florida. A mean dose of 1650 cGy was directed to the periphery of the lesion, which almost always corresponded to the 80% isodose line. The mean lesion diameter was 23 mm. Seventy-six patients were treated with one isocenter. Angiography, performed at 1 year after radiosurgery in 41 of the 48 eligible patients, revealed an overall complete thrombosis rate of 39%. The 1-year thrombosis rate was highest in those patients with relatively small AVM's. Angiography was performed at 2 years posttreatment in 21 of the 25 eligible patients, demonstrating an overall complete thrombosis rate of 81%. This incidence did not correlate with lesion size: that is, large lesions (up to 35 mm in diameter) seemed just as likely to thrombose. Two patients (2.5%) experienced hemorrhage at some time after radiosurgical treatment, and both recovered. Two patients (2.5%) have sustained mild, but permanent, radiation-induced neurological complications.

Adolescent↗
PubMed1992

Linear accelerator radiosurgery at the University of Florida.

The University of Florida radiosurgical project began in 1986 with the following design criteria: the most accurate radiosurgical device possible, state-of-the-art computer hardware and software for dose planning, and a number of collimators sufficient to treat any lesion homogeneously. In this article we have reviewed how these goals have been met. Physical aspects of this device (accuracy, dose gradient, and dose-planning speed) as well as clinical results compare favorably with any other radiosurgical experience. We believe that LINAC radiosurgical systems are advantageous in terms of cost, variety of collimator sizes available, and currently available sophistication of computerized dose planning. In the near future, the development of conformal treatment may significantly change the entire field of radiosurgery by offering heretofore unobtainable dose plans for irregularly shaped lesions. In addition, LINAC systems may be adapted for stereotactically focused fractionated radiation therapy and for radiosurgical treatment of lesions elsewhere in the body. Accuracy and computer sophistication notwithstanding, we cannot emphasize strongly enough our belief that the least important determinant of radiosurgical results is the machine used to deliver the radiation. It is absolutely vital that all groups undertaking radiosurgery include neurosurgeons, radiation physicists, and radiation therapists who have spent considerable time studying and learning the myriad details necessary to produce consistently good results. All radiosurgical patients must be followed up carefully and studied so that we can learn how to better apply this technique. Only patients who are not candidates for conventional surgery should be treated radiosurgically, at least until much more is known about long-term success and complication rates. A patient never should be treated radiosurgically simply because the referring or treating neurosurgeon is uncomfortable with proven conventional procedures. All groups performing radiosurgery should strive to adhere to the highest possible standards. We are all responsible for verifying the adequacy of our radiosurgical systems. We are all responsible for selecting our patients well, treating them with a team approach that applies the latest available knowledge of our field, following up closely, and reporting our results honestly and thoroughly so that all can benefit. We owe this, at least, to our patients and to neurosurgery.

Adult↗
PubMed1991

Stereotactic angiography: an inadequate database for radiosurgery?

Stereotactic angiography has long been the imaging database for the radiosurgical treatment of arteriovenous malformations (AVM). The following analysis reveals systematic shortcomings in the methodology, resulting in errors in determining target shape, errors in determining target size, and errors in the identification of the true AVM "nidus."

Brain↗
PubMed1990

Prophylactic glutamine protects the intestinal mucosa from radiation injury.

Glutamine may be an essential dietary component, especially for the support of intestinal mucosal growth and function. This study evaluated the effects of a glutamine-enriched elemental diet, administered before whole-abdominal radiation on gut glutamine metabolism, mucosal morphometrics, and bacterial translocation. Rats were randomized to receive a nutritionally complete elemental diet that was glutamine-enriched or glutamine-free for 4 days. The animals were then subjected to a single dose of 1000 cGy x-radiation to the abdomen. After irradiation, all animals received the glutamine-free diet. Four days later the animals underwent laparotomy for sampling of arterial and portal venous blood, culture of mesenteric lymph nodes, and removal of the small intestine for microscopic examination. There was no difference in arterial glutamine or gut glutamine extraction between the two groups, but body weight loss was significantly diminished in the glutamine-fed rats. Rats receiving the glutamine-enriched elemental diet before radiation had a significant increase in jejunal villous number, villous height, and number of metaphase mitoses per crypt. Scanning electron microscopy confirmed the presence of an intact gut epithelium in eight of eight rats receiving prophylactic glutamine compared to one of eight animals in the glutamine-free group. Three of eight rats fed glutamine had culture positive mesenteric lymph nodes compared with five of seven rats receiving the glutamine-free diet. Glutamine exerts a protective effect on the small bowel mucosa by supporting crypt cell proliferation effect on accelerate healing of the acutely radiated bowel.

Animals↗
PubMed1990

A film phantom for routine film dosimetry in the clinical environment.

This paper describes a new film phantom we have designed that eliminates many of the problems found in phantoms used in film dosimetry. This phantom employs two sheets of solid water attached with nylon hinges and aligned with pins. It is made light-impermeable through the use of nylon hook-and-loop fasteners. This new design shows good agreement with ion-chamber measurements over the full depth of electron penetration.

Film Dosimetry↗
PubMed1990

Radiation physics.

Because radiosurgery requires the highest precision, it should be undertaken only with a team approach and with built-in redundance to avoid errors. All members of radiosurgical teams must understand the dosimetric tools. This article presents the terms and principles of medical physics used in radiosurgery and points out possible pitfalls.

Animals↗
PubMed1989

The University of Florida radiosurgery system.

A new, linear accelerator based radiosurgical system has been designed and tested. It incorporates a mechanical system of precision bearings to control all patient and accelerator movements. The dosimetry system allows near real-time examination of the isodose distributions in any computed tomography plane such that any treatment plan can be quickly optimized. Extensive testing shows a radiation beam accuracy of .2 +/- .1 mm. The dose gradient between the 90% and 10% isodose distributions compares favorably with any previously published radiosurgical method.

Angiography↗
PubMed1988

Postoperative radiation and implant capsule contraction.

Occasionally radiation is required as adjunctive therapy following mastectomy for breast cancer. The effects of radiation on a developing implant capsule are unknown, but they are very important in relation to the increased use of immediate reconstruction. Experiments were performed on rabbits to study the effects of postoperative radiation therapy on capsule contraction and thickness. The results of these experiments suggest that radiation has no effect on implant capsules.

Abnormalities, Radiation-Induced↗
PubMed1985

Carcinoma of the intact uterine cervix, stage IB-IIA-B, greater than or equal to 6 cm in diameter: irradiation alone vs preoperative irradiation and surgery.

This is an analysis of 123 patients with Stage IB-IIA-B carcinoma of the intact uterine cervix, 6 cm or greater in diameter, who were treated with curative intent at the University of Florida with radiation alone or radiation followed by a hysterectomy between October 1964 and February 1982. There is a minimum follow-up of 2 years in all patients; 87% of all recurrences and 91% of pelvic recurrences occurred within this time period. Examination of pelvic control rates, as well as disease-free survival, showed no significant advantage in pelvic control, disease-free survival, or absolute survival for either treatment group when compared by stage and tumor size. The incidence of severe complications was 6% for patients treated with irradiation alone and 15% for those treated with irradiation and surgery (p = 0.119).

Carcinoma↗
PubMedDate not supplied

Stereotactic radiosurgery.

Radiosurgery has become a widely accepted method of treating intracranial targets with a highly focused single dose of radiation. The technique allows the precise treatment of small targets through the use of stereotactic techniques. The ability to accurately focus and target tissues with both patient and gantry movements allows the production of sharp dose gradients. This permits large target doses and allows for the sparing of critical tissues which may only lie a few millimeters from the edge of the target volume. In order to carry out this technique, routine radiotherapy simulation and treatment planning must be replaced by virtual simulation and non-coplanar treatment planning. These procedures carry with them increased quality assurance responsibilities.

Brain Diseases↗