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Biomedical subjects

D Nori

Publications and source records attributed to D Nori.

98 records · Page 6Linked to original sources

Radiation therapy in lymphomatoid granulomatosis.

Two female patients with lymphomatoid granulomatosis have received radiation therapy for local, progressive, symptomatic lesions. One patient was a 56-year-old woman with concomitant brain and pulmonary lesions which progressed on cyclophosphamide and prednisone therapy. The second patient was a 62-year-old woman with a supraorbital mass which appeared and progressed on prednisone therapy. Both patients exhibited rapid response to radiation therapy, in terms of relief of symptoms and objective evidence of subsidence of local disease. A discussion of the nature of lymphomatoid granulomatosis and its treatment is presented with a review of the literature. One hundred sixty-five cases have now been described including the two in this study, and in only one previous case was radiation therapy utilized to treat local disease, prior to the two cases described herein.

Cyclophosphamide↗

Current issues in techniques of prostate brachytherapy.

Adenocarcinoma of the prostate is the most common malignancy diagnosed among men in the United States today. Brachytherapy permits conformal radiotherapy and dose escalation, and it offers the convenience of a single-day outpatient procedure which is very attractive to patients with a busy life-style. The reported potency preservation rates with brachytherapy are superior to both external beam radiation therapy (EBRT) and surgery. The older retropubic techniques have been replaced by ultrasound or CT-guided transperineal techniques. Prostate brachytherapy may be temporary or permanent, and the planning techniques for either approach are similar. This review briefly discusses the advantages and limitations of each. Temporary techniques may be used with low dose rate or high dose rate applications. The basic steps include assessing prostate volume by any diagnostic modality (CT or ultrasonography), determining total activity needed to encompass the gland and deliver the appropriate minimum peripheral dose, and determining the pattern of placement of the seeds within the gland. Preplanning may be done either by ultrasound or by CT. The operative technique requires the visualization of the prostate in three dimensions and is performed using combination of ultrasound and fluoroscopy or fluoroscopy in two axes. The New York Hospital technique employs CT-based preplanning along with ultrasound and fluoroscopy during the operative procedure. Special circumstances that necessitate neoadjuvant hormonal therapy include interference from the pubic arch and large volume glands. An analysis of patients with stage T2a disease treated at the New York Hospital-Queens, from 1990-1995, reveals an actuarial clinical freedom from relapse of 79% at 5 years and a 5-year biochemical freedom from relapse of 64% which is comparable to that reported for similar risk groups of disease by other centers. Potency is preserved in greater than 80% of patients in our series. Patient selection criteria include the pre-treatment prostate-specific antigen (PSA) level, tumor grade (Gleason), stage of disease, and presence or absence of bilateral positive biopsies and/or perineural invasion. Based on our review of the literature and our clinical results, we have divided patients with prostate cancer into good, intermediate and poor risk groups. We recommend brachytherapy as the sole procedure for good risk patients, and a combination of external beam radiation therapy (EBRT) and brachytherapy for the intermediate risk group. Future avenues for research include a search for improved imaging techniques and possibly newer isotopes.

Actuarial Analysis↗

Intraoperative brachytherapy in non-small cell lung cancer.

The lung cancer incidence and mortality rates have risen steadily each year. Survival rates during the same period have improved marginally even by the best treatment approaches. A small proportion of patients with limited disease can be offered surgical resection as the primary curative treatment. In a significant number of cases, complete resection of cancer is not possible either because the patient could not tolerate radical surgical approach or because the tumor is attached to important structures in the mediastinum precluding any surgical intervention. Intraoperative brachytherapy by various techniques offers the greatest advantage in these patients to deliver higher doses of radiation to the tumor without damage to the normal lung. Numerous intraoperative brachytherapy techniques are described to adapt to different clinical situations. Experience over the past 30 years has shown that these procedures are safe and well tolerated and can be used alone or as a boost in conjunction with external beam radiation. Published data show encouraging local control rates and survival compared with treatment by external radiation to higher doses.

Brachytherapy↗

The American Brachytherapy Society perspective on intravascular brachytherapy.

BACKGROUND: Recent clinical studies indicate that intravascular brachytherapy (IVB) can reduce the rate of restenosis substantially after angioplasty procedures. However, no clinical guidelines exist for optimal therapy. METHODS: The members of the IVB Subcommittee of the American Brachytherapy Society (ABS) identified the areas of consensus and controversies in IVB to issue the ABS perspective on IVB, based on analysis of published reports and the clinical experience of the members in brachytherapy. RESULTS: IVB is still experimental. The long-term efficacy, toxicity, the target tissue, and dose required for IVB are not established. The ABS recommends that IVB procedures must be performed, with careful attention to radiation-related issues, in the context of controlled multidisciplinary clinical trials with the approval of the institutional review board, the Nuclear Regulatory Commission, the Food and Drug Administration, and under an Investigational Device Exemption. The therapeutic radiologist, with a qualified radiation physicist, is responsible for dose prescription and delivery and needs to be present during the IVB procedure as part of this multidisciplinary team. The long-term outcome from these studies should be reviewed critically and published in peer-reviewed journals. The ABS endorsed the dosimetric guidelines of the American Association of Physicists in Medicine Task Group 60 (AAPM TG-60) report. The ABS recommends that dose specification be defined clearly; to allow comparisons between studies, the dose should be prescribed at 2 mm from the source for intracoronary brachytherapy and at an average luminal radius of +2 mm for peripheral vascular brachytherapy. The prescription doses at the above point is generally in the 12-18 Gy range. Comprehensive procedures for quality assurance, radiation protection, and emergencies should be in place before initiating an IVB program. Higher energy beta sources, lower energy gamma sources, dose-volume histograms, and correlation of three-dimensional reconstructions of delivered dose with patterns of failure are areas for further research. CONCLUSION: The ABS perspective on IVB is presented to assist the interventional team in developing protocols for the use of IVB in the prevention of restenosis. Long-term outcome data with a standardized reporting system are needed to establish the role of brachytherapy in preventing vascular restenosis. Endovascular brachytherapy is a new and evolving modality, and these recommendations are subject to modifications as new data become available.

Brachytherapy↗

External beam radiation therapy to prevent postangioplasty dialysis access restenosis: a feasibility study.

PURPOSE: To evaluate the feasibility and short-term side-effects of postangioplasty external beam radiation for patients with compromised arteriovenous dialysis accesses. MATERIALS AND METHODS: Ten patients with compromised arteriovenous dialysis accesses were studied. Following confirmation of access compromise by an angiogram, patients were treated by a standard angioplasty +/- stent deployment. The target volume incorporated a margin of 1 cm beyond the angioplastied segment. The first 5 patients were treated to a dose of 12 Gy in two 6-Gy fractions spaced 48 h apart, whereas the next 5 patients were treated to 8 Gy in two similarly separated 4-Gy fractions. Five of the patients had at least one prior access that had failed. The current access had been in use for 6-52 months, and 5 of the 10 patients had at least one episode of compromise involving the current access. The length of stenosis ranged from 2 to 9 cm (mean 4.4 cm). All patients were followed clinically for adequacy of dialysis; a radiological follow-up with a fistulogram was performed for all in 3-monthly intervals. Follow-up ranged from 4 to 10 months, with a median follow-up of 6 months. RESULTS: There were no procedure-related complications. Three patients developed a restenosis at the site of the original stenosis, and one patient developed a restenosis at the edge of the stent. As part of the natural history of this process, five patients have also developed new lesions elsewhere in the proximal veins requiring radiological intervention. None of the patients showed any radiation-related side effects, either in the skin/ soft tissues, or in the vasculature on follow-up angiograms. CONCLUSIONS: Several different radiotherapeutic approaches are being currently investigated to prevent postangioplasty restenosis. There are several issues involved with the use of endovascular brachytherapy in these patients. On the other hand, given the superficial location of the dialysis access, we believe that external beam radiation offers a safe and simple method of radiation therapy in this setting. The clinical efficacy of this modality needs to be established through a randomized phase III trial.

Adult↗

Current therapy in the management of heterotopic ossification of the elbow: a review with case studies.

Heterotopic ossification, or the appearance of ectopic bone in para-articular soft tissues after surgery, immobilization, or trauma, complicates the surgical and physiatric management of injured joints. The chief symptoms of heterotopic ossification are joint and muscle pain and a compromised range of motion. Current therapies for prevention or treatment of heterotopic ossification include surgery, physical therapy, radiation therapy, and medical management. Unlike heterotopic ossification of the hip, heterotopic ossification of the elbow has not been extensively investigated, leaving its optimal management ill-defined. To remedy this deficiency, we review risk factors, clinical anatomy, physical findings, proposed mechanisms, and current practice for treatment and prevention of heterotopic ossification. We then consider and draw conclusions from four cases of elbow injury treated at our institutions (three complicated by heterotopic ossification) in which treatment included surgery, radiation therapy, physical therapy, and medical therapy. We summarize our institutional practices and conclude with a call for a randomized clinical trial to better define optimal management of heterotopic ossification of the elbow.

Adult↗