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Biomedical subjects

B Emami

Publications and source records attributed to B Emami.

At least 109 records · Page 6Linked to original sources
PubMed1988

Phase I/II study of treatment of locally advanced (T3T4) non-oat cell lung cancer with high dose radiotherapy (rapid fractionation): Radiation Therapy Oncology Group Study.

The Radiation Therapy Oncology Group (RTOG) completed a pilot study to test the feasibility of high dose of radiation therapy and its impact on tumor control and survival. From April 1, 1983 through May 1985, a total of 56 patients were treated on this protocol. All patients had locally advanced disease without distant metastases. The treatment regimen consisted of delivering 7500 cGy in 28 fractions over 5.5 weeks to the tumor, while the nodal bearing areas received 5040 cGy in the same period (daily dose to the mediastinum was 180 cGy; daily dose to gross tumor was 268 cGy). This is a considerably higher dose, with a TDF of 142 compared with a TDF of 92 (conventional fractionation of 6000 cGy in 6 weeks), which is the highest dose used in previous RTOG studies. Doses in this protocol (7500 cGy) was corrected for lung transmission whereas doses in prior RTOG protocols (6000 cGy) were uncorrected. Thus, after correction dose of 6600 cGy was calculated and coded for comparison. All short-term toxicities were acceptable, and the only major toxicity was one third-degree esophagitis in a patient with a follow-up of 12 months. Forty-four out of fifty-six patients received prescribed dose of irradiation. There were 17 complete responders and 15 partial responders, with an overall response rate of 32 out of 44 (72.7%). At the time of this report, there were 9 patients alive (NED); 5 died without tumor; and the remainder died of tumor or unknown.

Adult↗
PubMed1988

Hyperthermia in combination with definitive radiation therapy: results of a Phase I/II RTOG Study.

Between August 1981 and April 1986, 133 patients with superficial malignant tumors not previously treated with radiotherapy were entered on a Phase I/II RTOG study evaluating hyperthermia plus definitive radiotherapy. Eligible patients included those with superficial epithelial or mesenchymal tumors less than 4 cm in depth. Protocol radiotherapy specified a tumor dose of 60 Gy delivered in 1.8-2.0 Gy fractions 5 times/week with a boost of 5-10 Gy through reduced portals to residual tumor. Protocol hyperthermia, delivered twice weekly, was to start within 15 minutes following irradiation and to consist of 60 minutes of heat to a tumor temperature of 43 degrees C. Sixteen patients were excluded. Of the 117 eligible patients, the treated lesions had site/histologies which were 35% head & neck/squamous, 46% breast/adenocarcinoma, and 19% other site/histologies. Lesions were 3 cm or larger for 77% of patients. Of the 41 patients with head & neck/squamous lesions, skin or subcutaneous necrosis occurred within 6 months for 2% of the patients; 12% experienced thermal blisters. Fourteen patients were followed for 6 months or more following start of treatment; none of these experienced late toxicities more severe than telangiectasis. Complete responses were observed in 51% of these patients. Of the 54 patients with breast/adenocarcinoma lesions, skin or subcutaneous necrosis occurred within 6 months for 13% of the patients; 17% experienced thermal blisters. Thirty-seven patients were followed for 6 months or more following start of treatment; complications observed during this period included 13% with ulceration and one case of skin necrosis. Complete responses were observed in 85% of these patients. Local control was maintained at nearly this level for at least 2 years. Logistic regression analyses showed site/histology, greatest tumor diameter and average tumor temperature to be significantly related to response. Based on these promising findings, the RTOG has instituted a randomized Phase III study evaluating radiation therapy with or without hyperthermia in this patient population.

Adenocarcinoma↗
PubMed1987

Carcinoma of the extrahepatic biliary system--results of primary and adjuvant radiotherapy.

From 1975-1983, 20 patients with primary carcinomas of the gallbladder (GB) or extrahepatic bile ducts (EHBD) were irradiated with curative intent at the Washington University Medical Center and affiliated hospitals. Of the 17 patients with EHBD cancer, one received adjuvant irradiation after gross resection with positive microscopic margins. All others received primary irradiation for unresectable tumors, or for gross residual tumor after incomplete resection. The 8 patients receiving Ir192 implant in addition to external radiation showed improved (p = 0.06) survival compared to the 9 receiving external only: median 15 months (range 1.5-34 + months) versus 7 months (range 2.5-21 months). Failures were predominantly local-regional, with only one patient showing metastatic spread without known local-regional tumor. Adjuvant radiation therapy was given after cholecystectomy to 3 patients with GB cancers showing tumor extension beyond the serosa or to regional lymphatics. Of these, two survived at 22+ and 27+ months; the third died of local recurrence at 5 1/2 months. Although numbers are small, these results appear to support the use of adjuvant radiotherapy in patients with microscopic residual GB cancer. Aggressive local and regional radiotherapy can add to the quality and length of survival in both patient groups, that is, those with resectable lesions with high likelihood of microscopic residual, and also those with unresectable or gross residual disease after surgery.

Adult↗
PubMed1987

Combination of surgery, irradiation, and hyperthermia in treatment of recurrences of malignant tumors.

Management of recurrent tumors after initial treatment by surgery, radiotherapy, and sometimes chemotherapy is a formidable challenge. Proximity of tumor to critical organs (e.g., carotid artery in recurrent head and neck tumors) often makes radical surgery impossible. Prior definitive course of radiation therapy precludes delivering a second radical course of irradiation. In the Division of Radiation Oncology, Washington University, we have used combined postoperative hyperthermia and modest dose radiotherapy to treat 23 patients with recurrent tumors and postoperative residual disease. Generally, 3200 to 4000 cGy was delivered in eight to ten fractions in 4 to 5 weeks, in combination with eight to ten sessions of minimum tumor heating to 42.5 degrees to 43 degrees C for 60 minutes, twice a week as stated in the results. Follow-up period was one to 5+ years. Of the 23 patients treated, only three failed within the treatment volume.

Adult↗
PubMed1987

Large fraction irradiation with or without misonidazole in advanced non-oat cell carcinoma of the lung: a phase III randomized trial of the RTOG. Radiation Therapy Oncology Group.

The Radiation Therapy Oncology Group (RTOG) investigated the use of misonidazole as an hypoxic cell sensitizer in a Phase III prospective randomized trial employing radiotherapy, 600 cGy twice weekly to a total of 3600 cGy with and without misonidazole in the treatment of locally advanced non-metastatic squamous cell, adeno, or large cell carcinoma of the lung. Between January 1980 and July 1983, 117 patients from 21 institutions were enrolled. One-hundred eight patients were evaluable; 53 in the combined treatment arm and 55 in the radiation alone arm. Grade 3 or worse complications associated with radiation occurred in 17% of patients. Esophageal toxicity accounted for the majority of complications. Two (4%) patients in the radiotherapy plus misonidazole group experienced grade 3 peripheral neurotoxicity. Complete or partial responses were produced in 58% of the patients with radiotherapy alone and 36% of those treated with radiotherapy plus misonidazole (p = 0.08). At the time of first progression, over 50% of the patients had persistent local disease. Median survival was 7 months regardless of treatment. Misonidazole in the dose and schedule employed did not enhance the effect of radiotherapy on either local tumor control or overall survival in patients with advanced lung cancer.

Adolescent↗
PubMed1987

Postoperative radiation therapy in the management of lung cancer.

Postoperative radiation therapy for lung cancer is still controversial. In a 9-year period, 69 patients with non-oat-cell carcinoma of the lung (16% stage I, 26% stage II, and 58% stage III) received such therapy. The radiation dose was less than 5,000 cGy in 42 patients, 5,000-5,900 cGy in 16, and 6,000 cGy or more in 11; follow-up ranged from 24 to 64 months. Actuarial survival at 2 and 4 years was 50% and 16%, respectively, for squamous cell carcinoma, and 40% and 26% for adenocarcinoma. The 5-year survival for stages I, II, and III cancer was 29%, 17%, and 19%, respectively. Histologic findings and type of surgery did not affect survival, but the radiation dose apparently did. The 3-year survival for patients who received less than 6,000 cGy was 35%, compared with 73% for patients who received higher doses. In eight patients, treatment failed within the irradiated volume: all had received doses of less than 6,000 cGy, and the volume in three was judged to be inadequate.

Adenocarcinoma↗
PubMed1987

Malignant melanoma: analysis of dose fractionation in radiation therapy.

Thirty-five patients with 67 measureable cutaneous or lymph node metastases from malignant melanoma were treated with radiation therapy in a variety of total doses and dose fractions. There was no correlation between total dose and response rate. However, there was a strong correlation between fraction size and response rate. There were four (9%) complete responses in 43 lesions treated with fractions less than or equal to 500 rad (5 Gy) compared with 12 (50%) complete responses in 24 lesions treated with fractions greater than 500 rad (5 Gy) (P = .0006). Initial response rate was found to correlate strongly with local control at 1 year. The results were then analyzed with respect to lesion size, cutaneous versus nodal lesions, and site of cutaneous lesion (trunk, head and neck, or extremity). Correlation between fraction size and response rate was independent of lesion size, although there were fewer complete responses with increasing lesion size. Correlation was not seen in nodal lesions but was particularly striking in cutaneous lesions. This correlation was statistically significant only for cutaneous lesions of the extremities.

Dose-Response Relationship, Radiation↗
PubMed1987

State of the art of high energy photon treatment planning.

A virtual revolution in computer capability has occurred in the last few years, based largely on rapidly decreasing costs and increasing reliability of digital memory and mass-storage capability. These developments have now made it possible to consider the application of both computer and display technologies to a much broader range of problems in radiation therapy including dose computation, therapy planning and treatment verification. Various similar methods of three-dimensional dose computations in heterogeneous media capable of 2-3% accuracy are likely to be available, but significant work still remains especially for high energy X-rays where electron transport, and possibly pair production, needs to be considered. Innovative display and planning techniques are emerging and show great promise for the future. No doubt these advances will lead to substantially improved treatment planning systems in the next few years. However, it must be emphasized that for many of these applications a tremendous software and hardware development effort is required. Yet it is not clear whether the investments and efforts for improved capabilities and accuracies are warranted with respect to clinical outcome. The question must be addressed for the advancement in the practice of radiotherapy.

Humans↗
PubMed1987

Reirradiation of recurrent head and neck cancers.

Ninety-nine patients with recurrent cancers of the head and neck region were treated with surgery, radiation therapy, or combination therapy. The follow-up period ranged from 18 months to 18 years. An initial overall complete response rate of 67% and a partial response rate of 7% (overall response rate-74%) were achieved. The eventual tumor control rate was 15%. Although equal initial response rates were achieved in recurrences at the primary site and the cervical nodes, the eventual local control was better for the former (21% vs. 10%). Patients receiving less than 5,000 rad radiotherapy had a 44% complete response and an 11% eventual tumor control. Patients receiving over 5,000 rad had an 80% complete response and a 25% eventual tumor control.

Adult↗
PubMed1986

Neck neoplasms: MR imaging. Part I. Initial evaluation.

Untreated neoplasms of the neck (tumors of the oropharynx, supraglottic area, carotid body, and thyroid, in addition to malignant lymphadenopathy) were evaluated in 23 patients with magnetic resonance (MR) imaging. The results were compared with computed tomographic (CT) scans in 20 patients. Contrast between tumor and fat was best on relatively T1-weighted images (500/30-35 [TR msec/TE msec]), whereas separation of tumor and muscle was best with relatively T2-weighted pulse sequences (1,500/90). Balanced images (1,500/30-35) provided best overall image quality and best demonstrated vascular anatomy. MR imaging was usually superior to CT in showing the relationship of tumor mass to muscle. MR imaging and contrast material-enhanced CT were equivalent in most patients in defining vascular anatomy, but MR imaging was superior when intravenous contrast material was not administered. However, CT was more helpful in showing bone and cartilage anatomy, and in some patients CT also was better in showing airway abnormalities. Despite these limitations, MR imaging is a promising imaging technique for studying neoplasms of the neck.

Adult↗
PubMed1986

Neck neoplasms: MR imaging. Part II. Posttreatment evaluation.

Thirty-three patients who had undergone prior surgery and/or radiation therapy for malignant neoplasms of the neck were studied with magnetic resonance (MR) imaging. Twenty-seven of these patients were also evaluated with computed tomography (CT). Ten patients were healthy posttreatment volunteers, and 23 had documented tumor recurrence. MR images better demonstrated normal muscular landmarks, especially in patients with obliterated fat planes. Areas of posttreatment fibrosis or scarring were low in signal intensity with all MR pulse sequences. However, in three patients, high signal intensity from postradiation edema of the supraglottic area mimicked neoplasm. In patients with recurrent tumor, MR imaging was superior to CT in defining the relationship of tumor and muscle and in demonstrating vascular anatomy when no intravenous contrast material was given during the CT examination. In two patients tumor and fibrosis were separated on MR images because of signal intensity differences. CT scans, however, showed adjacent bone and cartilage anatomy better. Our data indicate that an MR examination may be helpful in patients in whom CT is indeterminate either because of anatomical distortion or suboptimal demonstration of vascular anatomy.

Head and Neck Neoplasms↗
PubMed1984

Effects of sequencing of the total course of combined hyperthermia and radiation on the RIF-1 murine tumor.

The optimal sequence for clinical utilization of combined radiotherapy and hyperthermia is not known. The clinical trials have resulted in similar responses whether hyperthermia is given before or after radiation. Moreover, studies addressing the best sequence for an entire course of multifractionated hyperthermia and radiation are lacking. In these experiments, the importance of sequencing of heat and irradiation in a multifractionated treatment regimen in RIF-1 murine tumors was studied. It was observed that a close sequence of heat and irradiation is more beneficial than separate cytotoxic action. When heat and irradiation were given simultaneously, (within 1 hour) 67% to 75% of the tumors were cured. Heat and irradiation given sequentially (the entire course of one following the entire course of the other, each separated by 72 hours) cured 20% of the tumors. No tumors were cured when treated with heat or irradiation alone. The tumor regrowth time (mean tumor doubling time) is much longer in simultaneous treatment than in sequential treatment. It appears that heating first decreases the effectiveness of subsequent irradiation, causing a shorter growth delay than the opposite sequence. Heat alone does not alter the tumor bed permanently, but irradiation seems to do so, resulting in a slower rate of growth upon recurrence.

Animals↗
PubMed1984

Physiological mechanisms in hyperthermia: a review.

In experimental animal systems, hyperthermia at therapeutic temperature (43-45 degrees C) causes a profound increase in blood flow in normal tissues while it induces only meager and temporal increases in blood flow in tumors. A severe vascular occlusion and hemorrhage usually follows the increase in blood flow in the tumors at the above temperatures. Another pronounced physiological change in tumors by heat is a prompt decrease in intratumor pH. The decrease in intratumor pH would accentuate the thermokilling of tumor cells and also possibly inhibit repair of thermodamage and development of thermotolerance in tumors. The temperature in tumors may rise higher than that in normal tissues during heating because of inefficient heat dissipation from the tumor as a result of decrease blood flow or vascular occlusion. Thus, the differential effects of heat on vascular function and pH in tumors and normal tissues may result in a greater damage in tumors than in surrounding normal tissues. Further investigation is urgently needed to find out whether similar physiological changes occur in human tumors and normal tissues by hyperthermia.

Animals↗
PubMed1984

Interstitial thermoradiotherapy in the treatment of recurrent/residual malignant tumors.

From October 1981-November 1983, a total of 31 recurrent and/or persistent tumors in 29 patients were treated with interstitial radiotherapy in combination with interstitial hyperthermia. All patients had undergone extensive previous treatments by surgery and/or radiation therapy. In the present series, radiation used was administered by iridium 192 implant, with doses varying from 4000-6000 cGy, delivered at the rate of 1000 cGy +/- 10%/day. Hyperthermia was delivered by radiofrequency (8 lesions) and microwave (25 lesions) in two sessions, each raising tumor temperature to a minimum of 42 degrees C over 60 minutes. Of 26 lesions with at least one satisfactory heating session, there were 18 (69%) complete responses, five (19%) partial responses, and three with less than 50% regression. None of the five lesions with unsatisfactory heating resulted in complete response. Of the total group, two patients developed a cutaneous sinus and one patient developed a fistula. The detailed methodology and results are presented and recommendations for future improvements are discussed.

Adult↗
PubMed1984

Utility of CT in detecting postpneumonectomy carcinoma recurrence.

After pneumonectomy for bronchogenic carcinoma, detection of recurrent disease in the ipsilateral hemithorax or mediastinum is often difficult. The authors discuss the utility of CT in the evaluation of 18 postpneumonectomy patients who had developed new clinical symptoms. In six patients without documented tumor recurrence, CT demonstrated a normal postpneumonectomy appearance. In the other 12, CT confirmed the clinical impression of recurrent neoplasm (10 prospectively, two retrospectively), which appeared either as enlarged mediastinal lymph nodes or as a soft-tissue mass projecting into the normal near-water-density postpneumonectomy space. In only five of these patients were plain chest radiographs suggestive of recurrence (two prospectively, three retrospectively). The accurate assessment of the presence and extent of recurrent neoplasm by CT was important in planning radiotherapy in eight patients.

Aged↗