Biomedical subjects

M A Lockett

Publications and source records attributed to M A Lockett.

44 records · Page 3Linked to original sources

PubMed1992

Adjunctive radiation therapy for rectal carcinoma.

From 1977 through 1985, 113 patients received radiation therapy in conjunction with definitive surgery for adenocarcinoma of the rectum. Posttreatment consisted of a minimum follow-up of 4 years. Radiation was given as postoperative (eight patients), short-course preoperative (2,000 cGy/5 fx, 21 patients), or as full-course preoperative treatment (4,500-5,000 cGy, 84 patients). Three patients received chemotherapy as part of the adjuvant treatment. The local control for the total group was 90% (local failures, 11 of 113), and the rate of recurrence at any site (distant or local) was 30% (34 of 113). Local failure was not significantly influenced by pretreatment clinical findings, tumor grade, or surgical stage. Because of distant failures, overall recurrence was significantly associated with surgical stage--0% (0 of 15) for Astler-Coller A, 23% (7 of 30) for B1, 25% (7 of 28) for B2, and 50% (20 of 40) for B3 or C lesions (p less than 0.01). Locally advanced pretreatment clinical findings were not independent of surgical stage as predictors of outcome. In particular, 14 of the tumors that received full course preoperative radiation were initially either nearly obstructing, circumferential, or deeply fixed. However, by the time of surgery, they were A or B1 lesions (probably down-staged lesions). Only one of 14 (7%) ultimately failed with a local and distant recurrence. There were four cases (3.5%) of small bowel obstruction requiring surgical management. Overall, there were 12 complications (11%) requiring either surgical or major medical management. The complication rate was not associated with radiotherapeutic factors. A strong association was noted between complications and the surgeon. Of 66 patients who had surgery with two colorectal specialists, four (6%) had serious complications. Of the remaining 47 patients who had general surgeons, eight (17%) experienced serious complications.

Actuarial Analysis↗

PubMed1991

Cervical stump carcinoma.

Although supracervical hysterectomy is becoming a vanishingly rare procedure, there are still many women with a retained cervical stump. We have reviewed 70 patients treated at the Radiation Oncology Center, Mallinckrodt Institute of Radiology for carcinoma of the cervical stump. The average time between the hysterectomy and the diagnosis of cancer in the stump was 26.6 years. The median age at diagnosis of 63.5 years is 8.5 years older than the median age at diagnosis of patients with cancer of the cervix with an intact uterus. Patients were treated with external beam radiation and/or intracavitary implants. Sixteen patients underwent surgery as well. The 5- and 10-year overall actuarial survival for all patients was 60% and 40%, respectively. The 5- and 10-year progression-free survival for all patients was 77% and 70%, respectively. Ten-year progression-free survival by stage was: 0--100%, 1A--100%, 1B--79%, 2A--100%, 2B--66%, and 3B--39%. Poor histologic differentiation correlated with a decreased long-term progression-free survival. Black patients, and those receiving prolonged courses of external beam irradiation, had a trend toward a worse prognosis. Neither non-squamous histology nor gross appearance affected outcome. With a median follow-up time of 12.9 years, there were only three isolated local failures and four combined with distant metastases. Complications were few, with twice as many occurring in the gastrointestinal system as in the genitourinary tract. We conclude that carcinoma of the cervical stump effectively treated by radiation therapy yields results equivalent to those seen in patients with an intact uterus.

Adult↗

PubMed1991

Impact of dose in outcome of irradiation alone in carcinoma of the uterine cervix: analysis of two different methods.

This is a retrospective analysis of 1211 patients with histologically proven invasive carcinoma of the uterine cervix with a minimum follow-up of 3 years treated with irradiation alone. The pelvic failure rates by stage were 9.6% for IB, 18.6% for IIA, 23% for IIB, 41% for III, and 75% for Stage IVA disease. External beam and intracavitary irradiation doses to point A and pelvic lymph nodes were calculated. In patients with Stage IB and IIA disease there was no significant correlation between doses to these points and pelvic tumor control. In Stage IIB doses of less than 6000 cGy to point A correlated with a high pelvic failure rate (8 of 12, 66.7%) in contrast to doses of 6000 to 9000 cGy (61 of 261, 23.4%) or higher than 9000 cGy (10 of 74, 13.5%) (p less than or equal to 0.01). In Stage III the pelvic failure rate with doses below 6000 cGy to point A was 72% (18 of 25) compared to 39% (71 of 180) for 6000 to 9000 cGy or 35% (27 of 77) with doses above 9000 cGy (p less than or equal to 0.01). TDF calculation of doses was carried out. In Stage IB and IIA there was no significant correlation between TDF to point A and probability of pelvic recurrence. In Stage IIB with TDF below 135, the pelvic recurrence rate was 41.6% (20 of 48) compared to 20% (61 of 305) with higher TDF (p less than or equal to 0.01). In Stage III the pelvic failure rate was 51% with TDF below 160 (70 of 136) in comparison with 29.5% (46 of 156) with higher TDF (p less than or equal to 0.01). Grade 2 sequelae of therapy were noted in about 10% of the patients and grade 3 in 4.7% of patients with Stage IB (18 of 384), 10.2% (12 of 128) with Stage IIA, 9.3% (33 of 353) with Stage IIB, and 8.2% (24 of 293) with Stage III disease. Doses from external beam and intracavitary irradiation to the rectum or the bladder neck were calculated. The actuarial incidence of major rectal or rectosigmoid sequelae was 2% to 4% with doses to the rectum of 6000 to 8000 cGy, 7% to 8% with 8000 to 9500 cGy, and 13% with doses higher than 9500 cGy (p less than or equal to 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Brachytherapy↗

PubMed1991

The effect of volume of disease in patients with carcinoma of the uterine cervix.

This is a retrospective study of 635 consecutively treated patients with FIGO Stage IIB or IIIB carcinoma of the uterine cervix. All patients were treated definitively with radiation therapy. The effect of volume of disease on outcome was studied. The 5-, 10-, and 15-year disease-free survivals (DFS) for the 346 Stage IIB patients were 64%, 61%, and 58%, respectively. Corresponding DFS for the 289 Stage IIIB patients were 40%, 38%, and 34%, respectively. The presence of bilateral parametrial invasion did not alter the 10-year DFS in Stage IIB patients (61% vs 64%, p = 0.60) but did decrease it in Stage IIIB patients (34% vs 50%, p = 0.006). Patients with both Stage IIB and IIIB cancers and central bulky disease (greater than or equal to 5 cm in diameter) had decreased DFS when compared to those without central bulky disease. Stage IIB patients with the lateral half of the parametrium involved had a decreased 10-year DFS in comparison with medial half involvement (52% vs 68%, p = 0.004). The total pelvic failure rate was 23% for Stage IIB and 41% for Stage IIIB patients. Central bulkiness increased the pelvic failure rate by about 11% for all patients. Bilateral parametrial disease increased the pelvic failure rate in Stage IIIB patients but not in patients with Stage IIB disease. The total pelvic failure rate for Stage IIB patients was greater in those whose disease extended into the lateral parametrium. Multivariate analysis was done using stage, lateral pelvic wall dose, parametrial disease, central bulkiness, age, and total dose to point A as variables. With local control as the endpoint, only stage (IIB vs IIIB) was significant (p = 0.008). Using DFS as the endpoint, stage (p = 0.0001) and central bulkiness of tumor (p = 0.026) were significant. Complications were not increased in patients with bulky or bilateral disease. We conclude that there is justification for subdividing FIGO Stage IIIB patients into those with unilateral or bilateral disease; however, these data do not support such a division for FIGO Stage IIB patients. These latter patients would be better analyzed with reference to medial versus lateral parametrial extension because of the difference in pelvic control and survival.

Adenocarcinoma↗

PubMed1990

Carcinoma of the prostate stage B and C: lack of influence of duration of radiotherapy on tumor control and treatment morbidity.

Between 1966 and 1985, 542 of 585 patients with histologically confirmed carcinoma of the prostate, Stages B and C, were treated with definitive radiation therapy to a minimum of 6300 cGy. There were 191 Stage B patients and 351 Stage C patients. The median tumor dose for Stage B patients was 6957 cGy and for Stage C patients 7020 cGy. Daily fractions of 180 to 200 cGy were given 4 or 5 times per week with occasional rest periods of several days, usually because of side effects of radiation therapy. The minimum follow-up time was 3 years; maximum follow-up was 16.0 years, and the median was 4.8 years. In this analysis, within each stage, patients were divided into four groups based on the number of treatment days: less than or equal to 56 days (8 weeks), 57 to 63 days (9 weeks), 64 to 70 days (10 weeks), and greater than 70 days. The distribution of Stage B and Stage C patients by histologic grade and duration of therapy is fairly even within each group. The influence of duration of radiotherapy on actuarial survival, progression-free survival, pelvic control, and incidence of complications was analyzed, and no statistical difference among the four groups of patients was found. The scatterplots of pelvic failure by radiation dose and duration of radiotherapy for both Stage B and C prostate carcinoma patients did not show a correlation between failure rate and duration of radiotherapy. Tumor histologic grade did not influence the incidence of pelvic failure. In summary, within the dose range used in this analysis the overall length of radiation treatment time did not seem to affect the clinical outcome of patients with Stage B and C prostate carcinoma.

Adenocarcinoma↗

PubMed1989

Outcome of recurrent cervical carcinoma following definitive irradiation.

This report is a retrospective analysis of 376 patients with recurrent cervical carcinoma, following definitive radiation therapy to 1054 patients with stage IB-IVA carcinoma of the uterine cervix treated at the Radiation Oncology Center, Mallinckrodt Institute of Radiology, from January 1959 through December 1982. The sites of failure after treatment by stage at initial diagnosis were classified as pelvic only (P), pelvic plus distant metastasis (P + DM), or distant metastasis only (DM). The sites of first failure were for stage IB, P = 0.8%, P + DM = 7.4%, DM = 7.9%; for stage IIA, P = 1.7%, P + DM = 14.7%, DM = 17.2%; for stage IIB, P = 10.4%, P + DM = 11.0%, DM = 14.9%; for stage III, P = 15.4%, P + DM = 23.9%, DM = 18.9%; and for stage IV, P = 16.7%, P + DM = 61.1%, DM = 16.7%. The actuarial probability of pelvic failure at 5 years from initial therapy was 8% for stage IB, 16% for stage IIA, 21% for stage IIB, 42% for stage III, and 100% for stage IV. The incidence of distant metastasis at 5 years was 14, 32, 28, 47, and 100% for stages IB, IIA, IIB, III, and IV, respectively. The therapy after failure was surgery, irradiation, irradiation plus surgery, or chemotherapy. There appeared to be no major difference in survival after recurrence by type of treatment or initial stage. The overall survival at 5 years for all untreated patients was 1%. The median survival was evaluated as a function of time to failure after initial treatment. Patients who developed disease more than 36 months after initial treatment had a median survival of 22.5 months. The median survival was 12.1, 7.6, 9.4, and 9.1 months for those failing less than 6, 6-12, 13-24, and 25-36 months after initial treatment. Severe treatment complications occurred in 3.6% (5/140).

Carcinoma↗

PubMed1989

Factors influencing outcome of definitive radiotherapy for localized carcinoma of the prostate.

Definitive radiation therapy was administered to 577 patients with histologically confirmed carcinoma of the prostate localized to the pelvis. Results of therapy and prognostic factors are evaluated and compared with other reports. All patients were followed for a minimum of 3 years, the median period of observation is 6.5 years. The disease-free survival in stages A2 and B was 78% at 5 years and 60% at 10 years; in stage C, 60% at 5 years and 36% at 10 years. The overall actuarial survival in stage B patients was 76% at 5 years and 58% at 10 years, which is similar to the life expectancy of a comparable cohort of normal males. In stage C, the actuarial survival was 65% at 5 years and 38% at 10 years, approximately 15% below the normal life expectancy for a similar cohort. Histological differentiation of the tumor had a significant impact on survival, poorly differentiated tumors showing 20% lower survival rates, most likely related to a higher incidence of distant metastases. Age was not found to be a significant prognostic factor in patients with stage B tumors; however, in stage C, the 5-year disease-free survival was 43% in patients younger than 60 and 53% in those older than 60 years (p = 0.04). In stage B, patients who had control of the pelvic tumor exhibited a 80% actuarial 5-year survival and 60% at 10 years. This compares with an actuarial survival of 30% at 5 and 10 years when there was evidence of pelvic recurrence alone or combined with distant metastases. In stage C patients with pelvic tumor control, actuarial survival was 81% at 5 years and 50% at 10 years, in comparison with 20% 5-year and 10% 10-year survival when pelvic recurrence or distant metastases or a combination of both occurred. The method of diagnosis [transurethral resection of the prostate (TURP) versus needle biopsy] did not appear to be a major prognostic factor of survival or patterns of failure, except in patients with stage C moderately differentiated tumors. The interpretation of the lymphangiogram (normal, suspicious or abnormal) did not correlate with survival or tumor control. The pathologic status of the lymph nodes established at lymphadenectomy did not appear to relate to survival for patients with stage B disease.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenocarcinoma↗

PubMedDate not supplied

New trends in prostatic cancer research. Three-dimensional conformal radiation therapy (3-D CRT), brachytherapy, and new therapeutic modalities.

In prostatic cancer research three-dimensional conformal radiation therapy (3-D CRT), brachytherapy and new therapeutic modalities have been applied. Treatment planning and delivery of radiation therapy have substantially evolved in the past 20 years. The treatment of localized carcinoma of the prostate with 3-D CRT is described, preliminary clinical results are presented and compared with those with standard radiation therapy (SRT). The benefit of 3-D CRT hypothetically could be linked to improved local tumor control because of a better coverage of the target volume with a specific dose of irradiation, less acute and late toxicity, possibility of carrying out dose-escalation studies. Intensity modulated radiation therapy (IMRT) may be particularly useful in some cases. Further efforts are necessary with collaboration of urologists and radiation oncologists to continue to explore approaches to optimally select and manage patients with localized prostate cancer. A reliable assessment of the impact of 3-D CRT and IMRT on outcome should come from prospective randomized long-term studies. As for brachytherapy, standardized protocols should be developed to objectively evaluate brachytherapy in localized prostatic cancer. Recently a great deal of interest has been focused on new therapeutic modalities with chemotherapeutic agents, a new agent named prostate specific enhancer, a regulatory element of the PSA gene is being tested. Laboratory and animal studies of the viral construct have been reported. A phase I human clinical trial is being initiated in the U.S.A. in patients with postirradiation hormone refractory prostate cancer.

Brachytherapy↗