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Biomedical subjects

J M Jenrette

Publications and source records attributed to J M Jenrette.

At least 19 recordsLinked to original sources

Fetal dose during radiotherapy: clinical implementation and review of the literature.

Two pregnant patients received radiation therapy, one for the treatment of mediastinal Hodgkin's lymphoma and the other for a head and neck squamous cell carcinoma. The fetuses were both protected by additional shielding which reduced the unshielded exposure of the first fetus by 20-40%, and that of the second by 20-60%. The first child received an estimated maximum dose of 42 cGy, the second a maximum dose of 9 cGy. Treatment details are reported and a review of the literature that addresses the possible irradiation-induced side effects at low doses is included.

Adult↗

Survival with combined modality therapy after intracerebral recurrence of pleuropulmonary blastoma.

BACKGROUND: We present and discuss the successful treatment of pleuropulmonary blastoma metastatic to the brain using a multimodality regimen with surgery, high-dose chemotherapy and radiation therapy. PROCEDURE: A 3-year-old boy referred to our institution with bilateral pulmonary cysts was diagnosed with pleuropulmonary blastoma (PPB). Initial treatment included surgery and multiagent chemotherapy with vincristine, dactinomycin, cyclophosphamide, cisplatin, and doxorubicin. One year after the completion of therapy, his PPB recurred as an intracerebral metastasis, and required further treatment with a multimodality salvage regimen. The child was successfully treated with a subtotal surgical resection, followed by high-dose cyclophosphamide, and radiation therapy. He is now disease-free 24 months later. RESULTS: Intracerebral metastases of PPB have been a uniformly fatal complication of this tumor. Postsurgical chemotherapy and radiation therapy appear to have contributed to the prolonged survival and potential for cure in our patient. CONCLUSIONS: The use of this multimodality regimen may be warranted in other patients with recurrent PPB metastatic to the brain.

Brain Neoplasms↗

Dynamic stereotactic radiosurgery: the Charleston program: a report on the first 150 patients.

We have been pleased with our initial experience in an evolving program. As newer surgical and radiotherapy techniques have become available, the role of radiosurgery has been and will continue to be modified. As more commercially available systems have been marketed, the availability will become more widespread. A battery of residents in neurosurgery and radiation oncology trained in these technologies will provide leadership and future directions of this therapy.

Adolescent↗

Malignant melanoma: the role of radiation therapy revisited.

In a multidisciplinary approach to the treatment of malignant melanoma, the role of radiation therapy is often relegated to one of minor importance. There is a supporting body of scientific literature that shows a relative radioresistance of melanoma when compared with other malignancies. Others have disputed the notion of resistance and have recommended radiation in a number of clinical settings including not only palliation but also in the primary management of melanoma. This article reviews the current and historical literature to better define the current role of radiation in a multidisciplinary approach for cancer management.

Clinical Trials as Topic↗

Treatment planning optimization for multiple arcs stereotactic radiosurgery using a linear accelerator.

PURPOSE: Multiarc stereotactic radiosurgery is a technique used to irradiate an intracranial tumor with minimal damage to the surrounding normal tissue. The purpose of this paper is to present a method for and the results from optimizing three dimensional (3D) treatment dose for multiarc stereotactic radiosurgery. METHODS AND MATERIALS: The normal procedure for a physician-physicist team designing a treatment plan for multiarc stereotactic radiosurgery is the trial-and-error approach of changing the collimator size and the isocenter of radiation by viewing the isodose curves on a two dimensional (2D) computed tomography (CT) or magnetic resonance imaging (MRI) image plane. Not only is this time consuming, but the resulting treatment plan is not optimal in most, if not all, cases. One reason for such nonconformal isodose curves is that the same collimator size is used for all arcs. However, it is very difficult to determine manually the different collimator sizes for different arcs. A derivative free optimization method is used to optimize the collimator size for each arc, as well as the 3D coordinates of the isocenter(s). RESULTS: One spherical and two ellipsoidal artificial tumors, and one actual tumor, were used to show the utilities of the optimization process. The 90% isodose curves resulting from optimization conform very well with the tumor; whereas the 90% isodose curves from the conventional method either do not envelop the entire tumor when the collimator size is too small, or a large volume of normal tissue is also irradiated by the 90% dose when the next larger collimator size is used. CONCLUSIONS: When the collimator size for each arc and the location of the isocenters(s) are optimized in a multiarc stereotactic surgery treatment plan, the 90% isodose curve conforms to the tumor much better than when the same collimator size is used for all arcs.

Algorithms↗

Combined modality therapy in the treatment of epidermoid carcinoma of the anus at the Medical University of South Carolina.

Treatment of anal epidermoid carcinoma by radiation and chemotherapy does offer an excellent opportunity to maintain quality of life. No patient in this series suffered long-term complications; and all have maintained rectal, anal, and sexual function. Patients with early stage lesions (AJC I-II) are most amenable to anus conserving therapy for epidermoid cancer of the anus. The success rate is markedly diminished in patients having more advanced disease, with patients possessing AJC stage III and VI disease presenting major problems. The possibility of post operative radiation therapy is markedly compromised by preoperative radiation therapy. Clinical surveillance and early recognition of these lesions by primary physicians can now offer patients with lesser stage cancer of this type excellent opportunity for organ preservation therapy. For those patients presenting with Stage III and VI carcinoma of the anus the aforementioned problems should be addressed and discussed before initiating conservative therapy.

Adult↗

Dynamic stereotactic radiosurgery using a linear accelerator.

We describe a system for stereotactic radiosurgery with a linear accelerator. This technique allows treatment of small (less than 40 mm diameter) intracranial lesions, including vascular malformations, and primary and metastatic tumors that are deep within the brain or in areas not amenable to open surgery. A beam of ionizing radiation (1800 to 2500 cGy) is focused on the center of the lesion, which is determined by stereotactic localization. "Dynamic rotation" of the linac gantry and table continuously about this predetermined point ensures that only the lesion receives the full radiation dose, while the normal structures in the head receive minimal amounts of radiation. The system combines, for the first time in one place, elements of radiosurgical technique developed at various centers. Testing for accuracy compares favorably with results at other centers using linac-based systems as well as comparing favorably with the gamma knife.

Brain Neoplasms↗

Primary malignant extragonadal germ cell tumors. An analysis of the effect of the effect of radiotherapy.

A retrospective analysis was performed on all patients diagnosed with biopsy-proven extragonadal germ cell tumors at the University of Virginia (Charlottesville, VA), The Medical University of South Carolina (Charleston, SC), the Bethesda Naval Hospital (Bethesda, MD), and The Medical College of Virginia (Richmond, VA) for the time period of January 1965 to December 1984. A total of 54 patients were treated with the initial sites of presentation observed: mediastinum, 26; central nervous system, 14; retroperitoneum, eight; and sacrococcygeal region, six. Megavoltage irradiation was used in 44 patients with a dose range of 2400 to 5580 cGy (mean, 4213 cGy). With a minimum follow-up of 4.0 years and a mean follow-up of 10.8 years, the 5-year actuarial survival for the entire population was 57.8%. Local control was achieved in 26 of 44 (59%) of the irradiated population. Factors of prognostic significance included histologic type at presentation, site of presentation, and radiation doses greater than or equal to 4000 cGy. Radiotherapy appears to be an effective modality in patients with extragonadal seminomas; however, the nonseminomatous tumors do not appear to be as radioresponsive.

Adolescent↗

Intraperitoneal P-32 after negative second-look laparotomy in ovarian carcinoma.

Thirty-one patients underwent a negative second-look laparotomy between 1976 and 1986. Fourteen patients received intraperitoneal chromic phosphate (P-32) after a negative second-look laparotomy. There has been no local recurrence (zero of 14) and no deaths attributable to recurrent disease. Local control and disease-free survival are 100%, with a minimum follow-up of 2 years and a mean follow-up of 4 years. Seventeen patients received no further therapy because of patient refusal, poor diffusion, or other contraindications to P-32 installation. Four of 17 patients undergoing negative second-look procedures without the addition of P-32 have subsequently recurred. This difference is highly suggestive (P = .076). There have been no major complications with the addition of P-32. The use of intraperitoneal P-32 after negative second-look laparotomies on ovarian carcinoma is well tolerated and effective in preventing recurrence.

Female↗

Primary central nervous system germ cell tumors. Effect of histologic confirmation on radiotherapy.

Primary malignant intracranial germ cell tumors are rare lesions responsible for only 0.5% of all central nervous system (CNS) malignancy. With stereotactic localization these lesions can be safely biopsied, and histologic confirmation will affect the ultimate prognosis. This report is a multi-institutional retrospective analysis of 33 patients diagnosed with a primary CNS germ cell tumor. Tumors in 14 patients (42%) were histologically confirmed (13 germinoma and one embryonal cell carcinoma); 19 patients were treated with a presumptive diagnosis. All patients were irradiated with a dose range of 3950 cGy to 6000 cGy to the primary lesions. Eight patients received craniospinal irradiation, and 25 patients were locally treated. The 5-year actuarial survival for the entire population was 64%. The survival rate in patients with histologic confirmation was 79% versus 53% in the unbiopsied population. Radiation doses greater than 5000 cGy, radiotherapy volume, and age were prognostic factors in determining survival.

Age Factors↗

Primary malignant mediastinal germ-cell tumors and the contribution of radiotherapy: a southeastern multi-institutional study.

A retrospective review was performed by a multi-institutional study group to determine the contribution of radiotherapy to the management of primary malignant mediastinal germ-cell tumors. Twenty-seven patients diagnosed with a primary mediastinal germ-cell tumor between January 1965 and July 1985 form the basis of this study. Twenty-five of the 27 patients were male. Thirteen patients' tumors were diagnosed as seminoma and the remaining 14 patients' tumors had other germ-cell histologies. The single most important prognostic factor was histology, with a 5-year actuarial survival of 100% for the seminomas and only 8.8% for the remaining germ-cell varieties. If total surgical extirpation is not possible, biopsy may be adequate. Of the patients with seminoma, 11 of 12 had local control, and 3 of the 12 patients were treated with doses between 3,000 and 3,100 cGy. High doses for this variety of mediastinal germ-cell tumor might not be required. For the germ-cell tumors other than seminoma, no patient had local control with doses over the range of 3,000-4,750 cGy.

Adolescent↗

Radiation enteritis.

As the population receiving radiation therapy grows, so does the incidence of chronic radiation enteritis. A review of the pathology of chronic radiation enteritis reveals fibrosis, endarteritis, edema, fragility, perforation, and partial obstruction. Conservative management of patients with this disease is common. Because the obstruction is only partial, decompression is easily achieved with nasogastric suction and parenteral support. The patient is then often discharged on a liquid-to-soft diet. This therapeutic strategy does nothing for the underlying pathology. The problem, sooner or later, will return with the patient further depleted by the chronic radiation enteritis. We think surgical intervention is appropriate when the diagnosis of chronic radiation enteritis is assumed. The surgery in relation to this disease is high risk with a 30% mortality and 100% expensive morbidity. Early intervention seems to decrease these figures. All anastomoses, if possible, should be outside the irradiated area. Trapped pelvic loops of intestine should be left in place and a bypass procedure with decompressing enterostomies accomplished. The surgery should be performed by a surgeon with extensive experience with all kinds of bowel obstruction as well as experience in performing surgery in radiated tissue.

Enteritis↗

Computed tomography of acute radiation nephritis.

A patient with Hodgkin's disease received a fractionated 3,740 rad dosage over 4 weeks to a portal that included both kidneys. Three months later a computed tomographic scan obtained 2 hours after intravenous contrast injection demonstrated sharply demarcated, dense, persistent nephrograms corresponding to the irradiated areas. These changes are ascribed to acute radiation nephritis, reflecting tubular stasis and ischemia.

Child↗

Metastasis to the choroid complicating adenoid cystic carcinoma.

Two months after a complete response to doxorubicin hydrochloride and cyclophosphamide administered for systemic effects, with the disappearance of pulmonary and pleural metastases from adenoid cystic carcinoma of salivary origin, a patient experienced symptomatic choroidal metastasis with no other evidence of active disease. Irradiation produced complete disappearance of the choroidal metastasis and restoration of visual acuity. The literature is reviewed, and the unusual nature of this metastasis is discussed.

Carcinoma, Adenoid Cystic↗