PubMed Health⌕ Search

Biomedical subjects

J D Forman

Publications and source records attributed to J D Forman.

71 records · Page 4Linked to original sources
PubMed1993

Frequency of residual neoplasm in the prostate following three-dimensional conformal radiotherapy.

The incidence of residual neoplastic cells on prostatic biopsy following conventional external beam radiotherapy is reported to range from 40-90%. As a result, it has been stated that current modalities of radiotherapy may carry an unacceptable local failure rate even in patients irradiated for low stage disease. In order to assess the potential benefits of three-dimensional (3-D) treatment planning, an unselected, consecutive group of patients with localized adenocarcinoma of the prostate was evaluated. This study was designed to determine the frequency of residual cancer in the prostate two years following definitive external beam radiotherapy designed, using a 3-D planning system. Between February 1988 and February 1989, 30 consecutive patients with localized (Stage T1-T3NxMo) adenocarcinoma of the prostate received definitive external beam radiotherapy. All treatment fields were designed with a computed tomography (CT)-based 3-D treatment planning system, resulting in a static conformal radiotherapy plan. The minimum dose delivered to the target volume, which included the prostate, periprostatic tissues, and a 1 cm margin, was between 65 and 69 cGy. Twenty-six patients had Stage T1, T2NxMo primary tumors and four were T3NxMo. Two years following the completion of treatment, all patients underwent digital rectal examination, transrectal ultrasound examination of the prostate with multiple biopsies, bone scan, and serum prostate specific antigen (PSA) determinations. Residual prostate cancer was proven by biopsy in six of 30 patients (20%). Four of 26 (15%) with Stage T1 and T2 tumors had a positive biopsy. However, two of the four Stage T3 tumors had postradiation biopsies positive for cancer (50%). Only one patient with a positive biopsy had an abnormal rectal examination. Five of the eight patients with elevated serum PSA levels after two years had residual neoplasia identified on biopsy. One of six patients with an abnormal postradiation ultrasound had residual tumor. Only one of the 22 patients (5%) with a normal serum PSA at two years had a positive postradiation biopsy. In patients with localized prostate cancer, the use of 3-D static conformal radiotherapy followed by multiple ultrasound guided biopsies confirmed the efficacy of external beam radiotherapy in low stage disease. We believe that the low incidence of positive biopsies in this study resulted from the benefits of 3-D treatment planning as well as the fact that all patients were evaluated, whereas past studies have been in selected patient groups when suspicion of residual disease existed prior to biopsy.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenocarcinoma↗
PubMed1993

Preliminary results of a hyperfractionated dose escalation study for locally advanced adenocarcinoma of the prostate.

The objective of this study was to build on our experience with 3-D conformal radiotherapy (CRT) by using a hyperfractionated dose escalation scheme to maximize the therapeutic ratio between improved local control and reduced morbidity in patients with locally advanced prostate cancer. Twenty patients with locally advanced (T3, T4) adenocarcinoma of the prostate were treated with a hyperfractionated radiotherapy schedule. All fields were designed with a conformal therapy based beam's eye view, 3-D planning system. The pelvic lymph nodes received 1.8 Gy/day to a total dose of 45 Gy in 5 weeks. Using partial transmission blocks, the prostate and periprostatic tissues received 1.3 Gy twice daily (minimum interval of 6 h) to a total dose of 78 Gy in 6 weeks. The dose was chosen by calculating the biologically effective dose (BED) which would produce the same effect in late reacting tissue but an increase for the tumor as our standard dose of 69 Gy delivered in 1.8-2.0 Gy fractions. The alpha/beta chosen for late damage was 3 Gy and 10 Gy was used for the tumor. All 20 patients completed the planned course of treatment. Although an increase in the tumor BED would be expected to result in increased acute effects, no significant worsening of acute side-effects was observed compared with standard treatment. All patients had only mild (Grade 1) rectal or bladder toxicity during treatment. One patient had an exacerbation of diverticulitis during treatment requiring hospitalization for antibiotics but completed treatment on schedule.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1993

Advantages of CT and beam's eye view display to confirm the accuracy of pelvic lymph node irradiation in carcinoma of the prostate.

Possible advantages of computed tomography (CT) and beam's eye view (BEV) display in the design of pelvic irradiation fields were studied in 20 consecutive patients with localized adenocarcinoma of the prostate. Pelvic fields were designed with standard four-field techniques. Then, CT and BEV display were done to define the reduced prostate tumor volumes. With treatment-planning CT, the location of the pelvic vascular structures (internal and external iliac artery and vein) was outlined. These were used as an approximation of the location of the lymph nodes. A BEV display of these lymph node volumes was then compared with the pelvic fields designed without CT and BEV display. Nineteen of the 20 patients had part of the CT-defined lymph node volume (a portion of the internal iliac lymph node volume) excluded from the original field design. Thirteen patients also had part of the external iliac nodal volume excluded. Dose-volume histograms showed that up to 30% of the lymph node volume received only 56% of the prescribed dose.

Adenocarcinoma↗
PubMed1993

Perspectives on the role of radiotherapy in organ-confined and locally advanced prostate cancer.

Radiotherapy is an effective management option in the treatment of organ-confined prostate cancer with survival results and local control possibilities similar to those of surgery. Although radiotherapy is used in locally advanced (stage-C) prostate cancer, there are significant developments that may make treatment more effective, such as hormonal cytoreduction, neutron radiotherapy and conformal therapy.

Humans↗
PubMed1992

The role of radiation therapy in the management of carcinoma of the male and female urethra.

Carcinoma of the urethra (male and female) is an unusual disease with insufficient clinical experience to be dogmatic about therapeutic recommendations. The onset is usually insidious, with a long interval from the first symptoms to diagnosis, yet lack of local and regional control remains the principal obstacle to cure. Treatment choices and results depend to a great degree on the extent, location, and stage of the lesion. Our conclusion is that good surgery and carefully planned irradiation are equally effective in the management of these tumors.

Brachytherapy↗
PubMed1991

Treatment planning issues related to prostate movement in response to differential filling of the rectum and bladder.

Conventional stimulation for patients with localized prostatic carcinoma often includes opacification of the dose limiting adjacent normal tissues. However, CT-based treatment planning is performed with the bladder and the rectum naturally filled or emptied. These latter conditions more closely approximate those in place at treatment Comparison of these CT-based treatment plans to simulator films taken with the rectum and bladder opacified yielded indirect evidence of movement of the prostate gland by 0.5 cm or more in 31 of 50 consecutive patients. The range of motion was 0 to 2 cm with an average of 0.5 cm (1.0 cm in the 31 patients). Six additional patients (five with local recurrence following I-125 seed implantation) were analyzed separately using CT scans. Registered CT images (3 mm slices) taken with the rectum and bladder full and/or empty provided direct evidence of prostate movement in 3 of the 6 patients. The dosimetric consequences of this movement are demonstrated using 3-dimensional dose distributions.

Computer Simulation↗
PubMed1989

Palliative hemiskeletal irradiation for widespread metastatic prostate cancer: a comparison of single dose and fractionated regimens.

Between 1986 and 1987 patients with hormone refractory metastatic adenocarcinoma of the prostate were treated with hemiskeletal irradiation. One group of 15 patients was treated with a fractionated regimen of 2500-3000 cGy in 9 to 10 fractions. A second group of 14 patients received a single dose of 600 cGy or 800 cGy depending upon whether the upper or lower hemiskeleton was irradiated. Both groups were similar with respect to their initial Karnofsky performance status and extent of disease. With the exception of one patient in the single dose group, all patients treated achieved complete or partial relief shortly after completion of their respective courses of therapy. Of the patients treated with single dose therapy, 10 of 14 (71%) ultimately needed retreatment in the region initially irradiated because of recurrent bone pain or spinal cord compression. In contrast, only 2 of 15 (13%) of the patients receiving the fractionated treatment course needed retreatment (p = .001). Although the median survival of both groups from the time of initial treatments was similar (10 and 11 months), the median duration for palliation was greater for those patients receiving the fractionated regimen as compared with single dose therapy (8.5 months vs 2.8 months). The incidence of treatment related toxicity was similar for both groups. We conclude that fractionated hemiskeletal radiation is a more effective means of palliation when compared to single dose therapy.

Adenocarcinoma↗
PubMed1987

NMR-pseudoenergy approach to the solution structure of acyl carrier protein.

A method for protein structure determination from two-dimensional NMR cross-relaxation data is presented and explored by using short amino acid segments from acyl carrier protein as a test case. The method is based on a molecular mechanics program and incorporates NMR distance constraints in the form of a pseudoenergy term that accurately reflects the distance-dependent precision of NMR cross-relaxation data. When it is used in an indiscriminant fashion, the method has a tendency to produce structures representing local energy minima near starting structures, rather than structures representing a global energy minimum. However, stepwise inclusion of energy terms, beginning with a function heavily weighted by backbone distance constraints, appears to simplify the potential energy surface to a point where convergence to a common backbone structure from a variety of starting structures is possible. In the case of the segment from residues 3 to 15 in acyl carrier protein, a nearly perfect alpha-helix is produced starting with a linear chain, an alpha-helical chain, or a chain having residues with alternating linear and alpha-helical backbone torsional angles. In the case of the segment from residues 26 to 36 a structure having a right-handed loop is produced.

Acyl Carrier Protein↗
PubMed1986

The correlation of pretreatment transurethral resection of prostatic cancer with tumor dissemination and disease-free survival. A univariate and multivariate analysis.

A multivariate Cox's hazard function analysis was performed on the prognostic variables selected from 240 patients with localized carcinoma of the prostate who received external beam radiotherapy to analyze the association between the method of biopsy and disease-free survival. The patients received 4500 cGy to the pelvis followed by a 2-week treatment rest and then an additional 2000 cGy to the reduced prostatic volume. Median follow-up was 4 years (range, 1-9 years). The 5-year actuarial local control rate was 91%. There was no difference in local control relative to the method of biopsy (needle biopsy or transurethral resection of the prostate [TURP]). The 5-year actuarial risks of metastases were 28% and 48% for the needle biopsy and TURP groups, respectively (P less than 0.01). The 5-year disease-free survival for the needle biopsy and TURP groups were 55% and 42%, respectively (P less than 0.05). This difference maintained statistical significance for Stage C and Grade III tumors. A multivariate analysis demonstrated that "method of biopsy" was the third most powerful variable after serum acid phosphatase level and modified Broders' grade in predicting disease-free survival. Patients who had TURP had an almost twofold higher relative risk of disease progression than those who had needle biopsy. This study established the correlation of the method of biopsy with a lower probability of disease-free survival over and above the information obtained from the clinical stage, histologic grade, presence or absence of symptoms of obstruction, acid phosphatase level, and lymph node status. The association of TURP with tumor dissemination is discussed with reference to the mechanism of metastasis formation and prevention.

Biopsy, Needle↗
PubMed1986

Definitive radiotherapy following prostatectomy: results and complications.

Thirty-four patients with carcinoma of the prostate treated by prostatectomy received postoperative external beam radiation. Sixteen patients were treated within 4 months of radical prostatectomy (group 1), 12 patients were treated for prostate carcinoma following initial enucleative prostatectomy for benign hypertrophy (group 2) and 6 patients were treated for palpable local recurrence 4 to 10 years following radical prostatectomy (group 3). The indications for postoperative radiotherapy following radical prostatectomy included extracapsular extension, seminal vesicle invasion, peri-prostatic soft tissue involvement, positive margins or palpable local recurrence. Eighty-five percent of the patients received whole pelvic radiation. All patients then had a 2-week treatment rest followed by a reduced portal to the prostate bed to a dose of 6500 cGy. The local control rate after radiotherapy was 100% with a median follow-up of 4 years. The 5-year actuarial survival and disease-free survival rates for all patients were 82 and 72%, respectively. In group 1, the 5-year actuarial survival and disease-free survival rates were 100 and 91%, respectively. In group 2, these rates were 77 and 64%. Three of the six patients in group 3 died within 30 months of radiotherapy. Fourteen patients (41%) had mild to moderate treatment related symptoms including seven patients (21%) with lower extremity or genital edema, five patients (15%) with urinary stress incontinence, two patients (6%) with urethral stricture and three patients (9%) with proctitis. Six of eight patients who were potent prior to radiation retained potency thereafter. No severe complications occurred. We conclude that external beam radiation therapy administered after prostatectomy resulted in an acceptable therapeutic ratio with 100% local regional control, and an acceptable complication rate (41%).

Aged↗
PubMed1986

Carcinoma of the prostate in the elderly: the therapeutic ratio of definitive radiotherapy.

Withholding or reducing the intensity and aggressiveness of treatment for elderly cancer patients is a widespread tenet lacking substantiation in the literature. To assess the potential value of definitive external beam radiotherapy in the elderly, an analysis of the therapeutic ratio between local regional control and complications was performed in 34 prostatic cancer patients more than 75 years old. Median followup was 5 years (range 2 to 8 years). The 5-year actuarial local regional control rate was 91 per cent. The 5-year actuarial survival rate was 81 per cent and the 5-year survival rate free of disease was 63 per cent. There were no severe complications. Mild to moderate chronic complications occurred in 3 patients (9 per cent). This treatment resulted in an excellent therapeutic ratio, which demonstrates that external beam radiation can be given to elderly patients with acceptable morbidity and gratifying results.

Actuarial Analysis↗
PubMed1985

Improving the therapeutic ratio of external beam irradiation for carcinoma of the prostate.

From 1975 to 1983, 240 patients with carcinoma of the prostate, Stages A2 to C, were treated with whole pelvic radiation followed by a 2-week rest and then a reduced field of radiation. The reduced prostatic field was evaluated for adequacy of tumor coverage by CT scan or ultrasound. The local regional control rate was 94%, with a 5-year actuarial survival for all stages of 72%. Severe complications occurred in 3% of patients and moderate complications in 13%. Two major factors that were identified as contributing to the risk of complications included previous or subsequent surgical intervention. Our technique of external beam radiotherapy resulted in a favorable therapeutic ratio, that is, excellent local-regional control with minimal morbidity.

Aged↗
PubMed1985

Gynecologic presentation of pelvic lymphoma.

Advanced pelvic lymphoma is rarely encountered by the gynecologist. Two cases of pelvic lymphoma involving the reproductive tract are reported. Long-term survival is achieved by minimal surgical intervention, correct histologic examination and treatment with local radiation therapy and systemic chemotherapy.

Adult↗
PubMedDate not supplied

Clinical strategies for improving the radiotherapeutic management of prostate cancer.

The goal of treatment of localized and locally advanced prostate cancer is to cure without causing unacceptable complications. The recognition that cure rates for localized and locally advanced prostate cancer treated with traditional means are far lower than previously estimated (1-4) has provided the impetus to seek improved local therapies. In particular, 3D conformal radiation therapy (3D-CRT) and the combination of radiation and hormone therapy are promising. Advances in these and other areas are discussed below.

Adenocarcinoma↗