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Biomedical subjects

R J Amdur

Publications and source records attributed to R J Amdur.

At least 37 records · Page 2Linked to original sources
PubMed1998

Prevalence of mood disorders and utility of the PRIME-MD in patients undergoing radiation therapy.

PURPOSE: To validate a short, structured interview procedure that allows practicing oncologists to quickly and reliably identify mood disorders in their patients, and to estimate the prevalence and types of mood disorders in a radiation therapy patient setting, noting relationships between mood disorders and patient characteristics. METHODS: Consecutive, eligible adult patients from the practices of two radiation oncologists were administered the Primary Care Evaluation of Mental Disorders (PRIME-MD) by the treating physician. A subset of these patients was also evaluated with the SCID, administered by trained mental health care personnel. Agreement between the two instruments was examined using the kappa statistic. Prevalence of mood disorders was determined from the PRIME-MD. The significance of relationships between patient characteristics and mood disorders was examined by chi-square and ANOVA analysis, and subsequently by multivariate logistic regression analysis. RESULTS: One hundred twenty-two patients were studied. Fifty-three of these were administered the SCID. Agreement between the two instruments was very good (kappa = 0.70). A diagnosis of a depressive or anxiety disorder by the PRIME-MD was made in 59 of the 122 patients (48%, 95% confidence interval = 39%, 58%). Multivariate analysis showed that a diagnosis of a depressive mood disorder was significantly related to pain intensity and prior history of depression. CONCLUSION: We have demonstrated the validity and feasibility of the PRIME-MD administered by oncologists in making diagnoses of mood disorders. The prevalence of mood disorders in our set of patients undergoing a course of RT was nearly 50%. Future studies should describe the natural history of these disorders, and determine optimal intervention strategies.

Adult↗
PubMed1997

Institutional review board approval and publication of human research results.

OBJECTIVE: To determine if journals' instructions for authors require that manuscripts being considered for publication indicate that studies involving human subjects had appropriate institutional review board (IRB) approval. DESIGN: A descriptive study of the ethical guidelines published in the Instructions for Authors sections of the 102 English-language biomedical research journals listed in the 1995 Abridged Index Medicus. INTERVENTION: Literature review. MAIN OUTCOME MEASURE: Policy regarding IRB approval of studies that involve human subjects. RESULTS: Of the 102 journals surveyed, 48 (47%) require IRB approval of studies involving human subjects as a prerequisite for publication, and 25 (24%) do not present or refer the author to any information related to human research ethics. Of the remaining journals, 15 (15%) referred authors to the Uniform Requirements for Manuscripts Submitted to Biomedical Journals, 3 (3%) to the Declaration of Helsinki, and 10 (10%) simply indicated that informed consent should be obtained. There was only 1 medical specialty (anesthesiology) in which all the representative journals presented the same ethical requirement. In the 48 journals that clearly required IRB approval of studies, 37 (77%) documented IRB approval with a statement in the manuscript, 7 (15%) required a separate signed statement from the author, and 4 (8%) did not mention a method of documentation. CONCLUSIONS: The results of this study suggest that about half of the 102 English-language biomedical research journals listed in the 1995 Abridged Index Medicus do not publish guidelines indicating that IRB approval of studies involving human research subjects is a requirement for publication. The manner in which publication requirements related to ethical standards are presented in biomedical research journals is extremely variable.

Codes of Ethics↗
PubMed1997

A simple, inexpensive applicator for irradiation of localized areas of the vagina with intracavitary brachytherapy.

PURPOSE: To describe the construction of a simple, inexpensive applicator for irradiation of localized areas of the vagina with intracavitary brachytherapy. METHODS AND MATERIALS: It was desirable to avoid an interstitial implant in an elderly patient with a stage T2 vaginal cancer. The final phase of radiation therapy was delivered with a custom made intracavitary cylinder that allowed the high-dose area to be limited to the portion of the vagina at high risk for residual disease. The applicator was fabricated from a clear cast acrylic (Lucite) rod with dimensions 3.5 cm diameter x 5.0 cm long. The applicator contained 11 parallel grooves, each 1.8 mm deep x 2.2 mm wide, machined along the surface of the cylinder parallel its long axis at 1.0 cm increments. Plastic needles (15 gauge) were inserted into the grooves along the surface of the acrylic cylinder and held in place with heat shrink tubing. The applicator was easily inserted and positioned without anesthesia. Standard low dose rate 192Ir ribbons were inserted into the plastic needles after positioning the applicator in the vagina. RESULTS: Construction of this applicator system requires a few weeks notice and approximately $150. Fabrication of the grooved cylinder is a routine task for a workshop with a milling machine. A step-by-step description of how to construct and use the applicator is provided along with the telephone numbers of commercial vendors to call to order all necessary materials. CONCLUSION: This article describes a simple, inexpensive method for constructing a customized vaginal applicator that can be used to treat a limited area of the vagina with intracavitary brachytherapy.

Aged↗
PubMed1996

Tissue-shrinkage correction factor in the calculation of prostate cancer volume.

Many studies that have calculated prostate cancer volumes from microscopic slides have used correction factors, ranging from 1.22 to 1.5, to compensate for tissue shrinkage during tissue processing. We undertook a study to measure tissue shrinkage directly because our experience suggested less shrinkage than that reported by others. Ten prostatectomy specimens were processed in a uniform manner. Multiple identical linear measurements were taken at four stages of processing: in the fresh state, following fixation, following processing, and from the microscopic slide. Linear shrinkage following fixation was minimal (4.1%) but increased to 14.5% following tissue processing. With rehydration and expansion on the flotation bath, tissues swelled so that net linear tissue shrinkage was 4.3%, and net volumetric tissue shrinkage was 12.4%, which translates into a correction factor for tissue shrinkage of 1.14. The following variables had no statistically significant effect on shrinkage: concentration of formalin, whole-mount versus quadrant sections, thickness of tissue slices, length of time in the alcohol dehydration steps, and temperature of the flotation bath over a range of 35 to 45 degrees C. This study suggests that (a) tissue-shrinkage correction factors that have been used in some previous studies may not be applicable for all laboratories because of interlaboratory variations in tissue-processing procedures or differences in measuring shrinkage; and (b) some calculated tumor volumes that have been used for prognostic thresholds may be high because of inflated tissue-shrinkage correction factors.

Humans↗
PubMed1996

5-fluorouracil and allopurinol combined with recombinant interferon-alpha 2b in the treatment of patients with advanced prostate cancer: a phase I/II study.

PURPOSE: We determined the toxicity and preliminary response rate of escalating doses of 5-fluorouracil (670 to 1,500 mg./m.2 per day) combined with a fixed dose of interferon-alpha 2b (5 million units) and allopurinol (300 mg. every 8 hours) in cohorts of patients with metastatic prostate cancer. MATERIALS AND METHODS: The trial included 11 men with metastatic prostate cancer. Cohorts of patients received a 5-day constant infusion of 5-fluorouracil combined with subcutaneous interferon-alpha 2b 3 times weekly and allopurinol for 1 week during 5-fluorouracil infusion. Treatment was repeat every 3 weeks. RESULTS: Of 10 patients evaluable for treatment response and toxicity 3 had a partial response as judged by significant decreases in prostate specific antigen measurements (mean followup 13.5 months). Significant dose limiting toxicities encountered included mucositis, diarrhea and leukoneutropenia. CONCLUSIONS: Further evaluation of this treatment to determine overall response rates and benefit should take into consideration the significant toxicity experienced.

Aged↗
PubMed1995

Arytenoid sparing during irradiation of early stage vocal cord cancer.

PURPOSE: Optimal position of the posterior field border when irradiating early stage vocal cord cancer is controversial. Several experts recommend moving the posterior field border 5-15 mm anteriorly after 50-60 Gy to decrease the chance of arytenoid edema. This article will evaluate the effect of field position on arytenoid dose. METHODS AND MATERIALS: 5 x 5 cm opposed lateral fields centered on the glottis were set up on a patient with typical anatomy. Isodose profiles were obtained with equally weighted 6 MV photon beams attenuated with 15 degree wedge filters using contours from an axial CT scan. Profiles with the posterior field border overlaying, 5, and 10 mm posterior to the posterior edge of the thyroid cartilage are presented. RESULTS: With the posterior field border 10 mm posterior to the thyroid cartilage, the arytenoids are included in the 95% isodose volume. Reducing the field by 5 mm has no significant effect on the position of the 95 and 90% isodose lines relative to the arytenoids. A field reduction of 10 mm places the arytenoids in the beam penumbra and leaves approximately 10 mm between the 95% isodose line and the midpoint of the true vocal cord. CONCLUSION: To achieve a significant dose differential between the arytenoids and the anterior portion of the vocal cord when using opposed lateral 6 MV photon beams the posterior field border must be at, or anterior to, the posterior edge of the thyroid cartilage. In view of the excellent results reported from institutions that include the arytenoids in the high-dose volume throughout treatment, it would seem appropriate to limit the use of arytenoid-sparing techniques to patients in whom there is no ambiguity about tumor location and in whom the treatment setup is very reproducible.

Arytenoid Cartilage↗
PubMed1994

Dose-rate effects between 0.3 and 30 Gy/h in a normal and a malignant human cell line.

PURPOSE: This study used continuous "intermediate" dose rate irradiation (0.3-30 Gy/h) to compare the capacity for and repair of sublethal radiation damage in different cell lines growing in tissue culture. METHODS AND MATERIALS: Two human cell lines were studied; one was derived from normal human fibroblasts (AG1522) and the other from a squamous cell carcinoma of the uterine cervix (HTB-35). Dose-response curves for clonogenic survival were determined following irradiation of plateau-phase cultures at five different dose rates: 22.6, 6.12, 3.65, 1.04, and 0.38 Gy/h. Subculture following irradiation was delayed for 8-24 h to allow for the full repair of "potentially lethal damage." RESULTS: A significant dose-rate effect was seen in both cell lines. For irradiation at the highest dose rate, survival at 2 Gy (SF2) and the alpha/beta ratio were similar for the two cell lines (approximately 0.7 and 8.0 Gy, respectively) but the half-time of repair of sublethal damage was estimated to be approximately five times longer in the normal human fibroblast line (154 min) than in the carcinoma (31 min) cell line. CONCLUSION: These results indicate that measuring the dose-rate effect between 0.3 and 30 Gy/h is a useful way to identify and quantify differences in sublethal damage repair between cell lines. To the extent that in vitro and in vivo repair parameters are similar, and that representative tumor biopsy specimens can be examined in this way, this approach may provide a prospective way of determining the dose rate (brachytherapy) or fractionation schedule that will optimize the therapeutic ratio.

Animals↗
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↗
PubMed1991

Pancoast tumor: radiation therapy alone versus preoperative radiation therapy and surgery.

This is a retrospective analysis of 73 patients with non-oat cell carcinoma of the lung presenting as a Pancoast tumor. All patients were treated with curative intent between October 1964 and September 1987 (minimum follow-up 2 years). The treatment plan consisted of preoperative radiation therapy (usually 3000 cGy in 2 weeks or 4500 cGy in 5 weeks) in 41 patients and radiation therapy alone (usually 6500-7000 cGy in 6.5-8.0 weeks) in 32 patients. In general, radiation therapy alone was reserved for poor-prognosis patients (extensive disease or medical inoperability). Although 41 patients were initially scheduled to receive preoperative radiation therapy and surgery, the surgery was not performed in 12 cases (29%) because of patient refusal (4 patients), poor response to radiation therapy (4 patients), distant metastasis (2 patients), or debilitation (2 patients). Separate calculations were carried out for the patients who completed the surgery as planned (preoperative radiation therapy and surgery) and the entire group originally scheduled for combined-modality therapy. There was no significant difference in the absolute or cause-specific survival rates between treatment groups, but severe complications were significantly more common in patients receiving combined therapy.

Adult↗
PubMed1990

Adenocarcinoma of the prostate treated with external-beam radiation therapy: 5-year minimum follow-up.

This is a retrospective analysis of 225 patients with localized adenocarcinoma of the prostate who were treated with continuous-course external-beam radiation therapy at the University of Florida between October 1964 and August 1982. All patients were treated 5 or more years prior to the date of analysis, and 30% were eligible for 10-year follow-up. Hormonal treatment was used only in the management of recurrent disease. Ten-year results by stage were as follows: local control--A, 96%; B1, 92%; B2, 51%; C1, 57%; C2, 76%. Relapse-free survival--A, 96%; B1, 58%; B2, 38%; C1, 43%; C2, 61%. Absolute survival--A, 69%; B1, 29%; B2, 47%; C1, 35%; C2, 50%. Freedom from distant metastasis--A, 100%; B1, 55%; B2, 71%; C1, 65%; C2, 77%. Tumor grade was an important prognostic variable in most of the subgroups analyzed. The 5-year rate of distant metastasis was significantly greater in patients with stage C disease when the biopsy was made by transurethral resection of the prostate (TURP) rather than by needle biopsy. In stage B patients, the biopsy method was not prognostically important. For the 48 patients who developed recurrent tumor in the prostate gland, with or without concurrent metastasis, the 5-year absolute survival rate calculated from the date of recurrence was 26%, compared with 10% for the 34 patients who developed distant metastasis alone. Severe complications developed in 5 out of 225 patients (2%) and included three severe rectal injuries, one bladder neck contracture, and one femoral head necrosis. Moderate complications developed in 48 out of 225 patients (21%), with rectosigmoiditis (8%) and hematuria (5%) being the most common problems. For both moderate and severe complications, there was a clear trend toward an increasing complication rate with increasing dose. The method of diagnosis appeared to be a factor in the development of urinary incontinence following irradiation: needle biopsy, 0/106 (0%); TURP, 3/112 (3%); subtotal prostatectomy, 1/7 (needle biopsy versus TURP or prostatectomy, p = 0.076). The frequency of peripheral edema following irradiation was influenced by a history of surgical disruption of the pelvic lymphatics: staging lymphadenectomy, 2/16 (13%), versus no lymphadenectomy, 0/209 (p = 0.005). A comparison with other series is presented.

Adenocarcinoma↗
PubMed1990

The effect of overall treatment time on local control in patients with adenocarcinoma of the prostate treated with radiation therapy.

Studies of patients treated with radiation therapy for squamous cell carcinoma of the head and neck have demonstrated that when all other variables are constant, protraction of the overall treatment time leads to a decreased probability of local control. Few data exist on the effect of overall treatment time on local control following irradiation of tumors that are generally thought to be slowly proliferating, such as adenocarcinoma of the prostate. This analysis was undertaken to determine the time-dose relationships for local control of prostatic adenocarcinoma at the University of Florida. All patients were treated at least 5 years prior to the date of analysis. For patients with Stage A2 disease, a tumor dose of 6500 cGy in 7 to 7.5 weeks to 7000 cGy in 8 weeks resulted in local control in 17/17 patients (100%). For patients with Stage B1 disease, the local control rate was 14/16 (88%) with an overall treatment time of less than or equal to 8 weeks versus 1/3 in patients who received split-course treatment in greater than 8 weeks (p = .097). For patients with Stage B2, C1, and C2 disease who received greater than or equal to 6500 cGy, the 5-year rate of local control was lower when overall treatment time was protracted beyond 8 weeks. Results were as follows: B2 (62 patients), less than or equal to 8 weeks, 88%, versus greater than 8 weeks, 55%, p = .002; C1 (87 patients), less than or equal to 8 weeks, 88%, versus greater than 8 weeks, 73%, p = .052; Cs (33 patients), less than or equal to 8 weeks, 81%, versus greater than 8 weeks, 65%, p = .056. Stratification by tumor grade of patients with Stage B1, B2, C1, and C2 disease who received greater than or equal to 6500 cGy demonstrated significantly lower local control rates for all grade categories when the overall treatment time was protracted beyond 8 weeks. Five-year local control rates (life-table method) for overall treatment time less than or equal to 8 weeks versus greater than 8 weeks were as follows: well differentiated, 93% versus 73% (p = .003); moderately differentiated, 86% versus 69% (p = .017); and poorly differentiated, 75% versus 59% (p = .046). These data suggest that tumor repopulation during excessively protracted treatment may be a clinically significant factor in patients with adenocarcinoma of the prostate.

Adenocarcinoma↗
PubMed1989

Postoperative irradiation for squamous cell carcinoma of the head and neck: an analysis of treatment results and complications.

One hundred thirty-four patients with advanced head and neck cancer were treated with radical surgery and postoperative radiation therapy between October 1964 and October 1984. All patients had greater than or equal to 2 years and 84% had greater than or equal to 5 years of follow-up. All patients included in the study were scheduled to receive continuous-course irradiation following a major cancer operation for previously untreated squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, or larynx and began radiation treatment less than or equal to 3 months after the surgical procedure. Ninety-six percent had AJCC pathologic Stage III or IV cancer, and all were without evidence of gross disease at the start of irradiation. The majority of recurrences above the clavicles occurred in the primary field (84%) as opposed to the posterior strip (8%) or low neck (8%). Based on multivariate analysis and tabular comparisons, 4 factors were found to be significantly important for predicting disease control above the clavicles: (a) Surgical margin (5-year actuarial control with invasive cancer at the margin, 53%, versus 81% with negative margins, p = .009). Patients with close margins or in situ cancer at the margins had the same rate of control as those with negative margins. (b) Primary site (oral cavity, 64%, versus other sites, 83%; p = .029). (c) Neck Stage (N0-1 versus N2-3). (d) Number of indications for irradiation--for example, bone invasion, multiple positive nodes, perineural invasion (1-3 indications, 85%, versus greater than or equal to 4, 62%; p = .06). The rate of disease control above the clavicles did not correlate well with AJCC pathologic stage: Stage I-II, 67%; Stage III, 81%; Stage IVA (T1-3, N2-3A), 68%; Stage IVB (T4 and/or N3B), 80%. The interval between surgery and the start of irradiation (range 1-10 weeks) also was not prognostically important, even with stratification by tumor dose, surgical margin, and number of indications for irradiation. At 5 years, the actuarial survival rate was 33% for the entire group; for patients with invasive cancer at the margin, the survival rate was approximately half that of those whose margins were free of invasive cancer (17% versus 37%). Based on multivariate analysis, 2 factors were found to significantly increase the probability of death due to cancer: (a) neck Stage (N0-1 versus N2-3); (b) extension of tumor from the primary site into the skin or soft tissues of the neck.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1989

Split-course versus continuous-course irradiation in the postoperative setting for squamous cell carcinoma of the head and neck.

There is very little published information comparing split-course and continuous-course irradiation in the adjuvant setting. To evaluate this issue, a retrospective analysis was performed of 161 patients with squamous cell carcinoma of the head and neck who received split-course (27 patients) or continuous-course (134 patients) irradiation following radical surgical resection. At 5 years, the actuarial rate of disease control above the clavicles for continuous-course irradiation was 80% versus 44% for split course (p = .002). Stratification of patients by primary site, surgical margin, AJCC stage, and tumor dose revealed a statistically significant (p less than or equal to .05) advantage in most of the subgroups for patients treated with continuous-course irradiation. The overall and cause-specific survival rates were also much better for patients treated with continuous-course irradiation, and the difference was highly statistically significant (overall 5-year survival, continuous course, 33%; split course, 15% [p = .005]; cause-specific 5-year survival, continuous course, 57%; split course, 37% [p less than .001]). A stepwise multivariate analysis confirmed that the type of irradiation course (continuous vs. split) was an independent prognostic variable of statistical significance for both control of disease above the clavicles and death with cancer present, with the split-course patients having worse results in both categories. The incidence of acute intolerance (4%) and late complications (7%) was the same in both the split- and continuous-course groups. As has previously been reported from this institution for patients treated with irradiation alone, these results demonstrate that in the postoperative setting, split-course irradiation yields lower local-regional control and survival rates compared with continuous-course therapy with no difference in the rate of severe complications. It is therefore recommended that split-course irradiation as used in this series be avoided whenever possible in patients with squamous cell carcinoma of the head and neck.

Adult↗
PubMed1988

Squamous cell carcinoma of the head and neck treated with radiation therapy: the impact of neck stage on local control.

There have been several recent reports in the literature to indicate that the risk of failure at the primary site following radiation therapy is greater in patients with a clinically positive neck as opposed to those with a clinically negative neck at diagnosis. This is an analysis of 526 patients with squamous cell carcinoma of the head and neck who were treated with irradiation alone to the primary lesion with curative intent. All patients had follow-up for at least 2 years and were evaluable for analysis of local control. For each site and T stage, no evidence was found to indicate that the primary lesions were controlled less often in patients whose necks were clinically positive than in those whose necks were clinically negative.

Carcinoma, Squamous Cell↗
PubMed1987

Carcinoma of the soft palate treated with irradiation: analysis of results and complications.

This is an analysis of 75 patients with squamous cell carcinoma of the soft palate and/or uvula treated with radical radiation therapy alone (64) or in conjunction with planned neck dissection (11) between October 1964 and September 1983. All patients have a minimum follow-up of 2 years and 60 (80%) have a minimum follow-up of 5 years. Patients were excluded from analysis of disease control at the primary site and/or neck if they died within 2 years of treatment with the site(s) continuously disease free. The initial local control rates and ultimate local control rates after surgical salvage of irradiation failures for patients treated with continuous-course irradiation were as follows: T1, 8/8 (100%) and 8/8 (100%); T2, 14/19 (74%) and 16/19 (84%); T3, 5/11 (45%) and 5/11 (45%); and T4, 1/4 (25%) and 1/4 (25%). Overall, 7/55 patients (13%) treated with continuous-course irradiation experienced irradiation-related bone or soft tissue complications; there was only one severe complication. The 5-year determinate survival rates by modified AJCC stage for patients treated with continuous-course irradiation are as follows: I, 83%; II, 78%; III, 38%; IVA, 0/2; and IVB, 25%.

Aged↗