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)

Nonrandomized evaluation of pelvic lymph node irradiation in localized carcinoma of the prostate

PURPOSE

A great deal of controversy exists regarding the potential benefit of pelvic lymph node irradiation compared with treatment to the prostate only in patients with localized prostate cancer. Despite numerous reports, including a randomized study, this issue has not been completely elucidated.

METHODS AND MATERIALS

A total of 963 patients with histologically proven localized adenocarcinoma of the prostate treated with definitive radiation therapy alone were analyzed. Median follow-up was 6.5 years (minimum: 2 years, maximum: 22 years). Pelvic lymph nodes received 40 to 55 Gy with anteroposterior/posteroanterior and sometimes lateral stationary portals in 1.8 Gy daily fractions; an additional dose was delivered to the prostate with 120 degrees bilateral are rotation to complete doses of 65 to 68 Gy for Stage A2 and B tumors and 68 to 71 Gy for Stage C tumors. The same total doses were delivered with smaller fields when the prostate only was treated.

RESULTS

In Stage A2 (T1b,c) the 10-year clinical pelvic failure rate was 16% regardless of the volume irradiated or tumor differentiation. With Stage B (T2) well- or moderately differentiated tumors, the 10-year pelvic failure rates were 22% when pelvic lymph nodes were irradiated and 32% when prostate only was irradiated (p = 0.41). With Stage A2 (T1b,c) and B (T2) poorly differentiated tumors, the 10-year pelvic failure rates were 32% and 7%, respectively (p = 0.72). With clinical stage C (T3) well-differentiated tumors treated with 50 to 55 Gy to pelvic lymph nodes, the pelvic failure rate was 22% compared with 37% in those receiving 40 to 45 Gy (p < or = 0.07). A significant reduction in pelvic failures was noted with Stage C poorly differentiated tumors when the pelvic lymph nodes received doses higher than 50 Gy (23%) compared with lower doses (46%) (p < or = 0.01). Volume or doses of irradiation did not influence incidence of distant metastases in any stage or tumor differentiation group. Disease-free survival did not correlate with volume treated in any clinical stage or tumor differentiation group. In 317 patients on whom pretreatment prostate-specific antigen levels were available, there is a suggestion that those treated to the pelvic lymph nodes had a higher chemical disease-free survival than those receiving prostate irradiation only. Follow-up is short, and differences are not statistically significant in any of the groups. Morbidity of therapy was slightly higher in patients treated to the pelvic lymph nodes, but in Stages A2 (T1b,c) and B (T2) differences are not statistically significant (4 to 6%). Stage C patients treated to the pelvic lymph nodes with 50 Gy had a 12% incidence of Grade 2 rectosigmoid morbidity compared with 6% in those treated with 40 Gy (p = 0.26).

CONCLUSIONS

In this retrospective analysis, pelvic lymph node irradiation did not influence local/pelvic tumor control, incidence of distant metastases, or disease-free survival in patients with clinical Stage A2 (T1b,c) or B (T2) localized carcinoma of the prostate. In patients with Stage C (T3) disease, irradiation of the pelvic lymph nodes with doses of 50 to 55 Gy resulted in a lower incidence of pelvic recurrences and improved disease-free survival. Morbidity of therapy was acceptable, although patients with Stage C disease had a somewhat higher incidence of Grade 2 rectosigmoid morbidity. Pelvic lymph node irradiation is being elucidated in properly designed prospective, randomized protocols.

Carcinoma of the tonsillar fossa: a nonrandomized comparison of irradiation alone or combined with surgery: long-term results

The results of therapy are reported in 296 patients with histologically proven epidermoid carcinoma of the tonsillar fossa; 127 were treated with irradiation alone (5,500 to 7,000 cGy), 133 with preoperative radiotherapy (2,000 to 3,000 cGy) or were initially planned for preoperative irradiation but treated with radiotherapy alone, and 36 with postoperative irradiation (5,000 to 6,000 cGy). The operation in all but 4 patients consisted of an en bloc radical tonsillectomy with ipsilateral lymph node dissection. Actuarial 5-year no evidence of disease (NED) was as follows: survival rates for patients with T1 tumors, 76%; T2, 54%; T3, 45%; and T4, 20%. Patients with no cervical lymphadenopathy or with a small metastatic lymph node (N1) had better relapse-free survival (60% to 70% at 5 years) than those with large or fixed lymph nodes (30% to 40%). Primary tumor recurrence rate in the T1-T2 groups was about 20% in patients treated with irradiation and surgery and 30% for those treated with irradiation alone (difference not statistically significant), 30% in patients with stage T3 lesions in all treatment groups, and 33% in patients with T4 disease treated with surgery and postoperative irradiation compared to 52% with irradiation alone (p = 0.03). The overall recurrence rate in the neck was about 20% for the N0 patients, 25% for N1, and 30% for those with N2 and N3 cervical lymph nodes in the 4 treatment groups. The incidence of contralateral neck recurrences was about 8% with the various treatment modalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Irradiation alone or in combination with surgery in stage IB and IIA carcinoma of the uterine cervix: A nonrandomized comparison

This is a report of a nonrandomized comparison of treatment results of 244 patients with stage IB carcinoma of the uterine cervix treated by radiation alone and 92 treated with preoperative radiation and surgery and 77 patients with stage IIA treated by radiation alone and 24 treated with a combination of radiation and surgery. The techniques of irradiation and types of operation are described in detail. The five-year tumor free actuarial survival for the patients with stage IB treated either with irradiation alone or combined with surgery was approximately 85% and the ten-year survival, 78%. For stage IIA the tumor free actuarial five-year survival without tumor was 73% and for ten years, 60%. In the 244 patients treated with radiation alone, there were ten central failures (4%) usually combined with distant metastasis. Further, 16 of these patients (6.5%) developed parametrial recurrence, in all but one instance associated with distant metastasis. In the 92 patients with stage IB treated with combined therapy, there were three local recurrences (3.8%), two of them combined with parametrial failures and six parametrial recurrences (6.5%), all of them concomitant with distant metastasis. Of the 77 patients with stage IIA treated by irradiation alone, there was one central recurrence alone and five local and parametrial recurrences, all of them associated with periaortic nodes or distant metastasis. Four additional patients had parametrial recurrences only concurrent with distant metastasis. Of the 24 patients treated with irradiation and surgery, there were two parametrial recurrences combined with distant metastasis (8.2%). There was no significant difference in the survival or recurrence rate of the patients treated with either method. In the group treated with combined therapy, patients with stage IB who showed evidence of microscopic residual tumor after irradiation had a failure rate of approximately 42% (8/18) in contrast to only 8.6% (6/70) in those with negative specimens. In stage IIA there were three failures in eight patients with residual tumor in the specimen in contrast to only two of 16 with negative specimens (12.5%). Major complications were comparable in both groups (radiation alone approximately 8.7% and irradiation combined with surgery approximately 14%), the difference is not statistically significant. The most frequent minor complication in patients treated with radiation alone was vaginal fibrosis (30 patients--9%) or vaginal vault necrosis (10 patients--3%).

Three-dimensional treatment planning and conformal radiation therapy: preliminary evaluation

Preliminary clinical results are presented for 209 patients with cancer who had treatment planned on our three-dimensional radiation treatment planning (3-D RTP) system and were treated with external beam conformal radiation therapy. Average times (min) for CT volumetric simulation were: 74 without or 84 with contrast material; 36 for contouring of tumor/target volume and 44 for normal anatomy; 78 for treatment planning; 53 for plan evaluation/optimization; and 58 for verification simulation. Average time of daily treatment sessions with 3-D conformal therapy or standard techniques was comparable for brain, head and neck, thoracic, and hepatobiliary tumors (11.8-14 min and 11.5-12.1, respectively). For prostate cancer patients treated with 3-D conformal technique and Cerrobend blocks, mean treatment time was 19 min; with multileaf collimation it was 14 min and with bilateral arc rotation, 9.8 min. Acute toxicity was comparable to or lower than with standard techniques. Sophisticated 3-D RTP and conformal irradiation can be performed in a significant number of patients at a reasonable cost. Further efforts, including dose-escalation studies, are necessary to develop more versatile and efficient 3-D RTP systems and to enhance the cost benefit of this technology in treatment of patients with cancer.

Design of a fully integrated three-dimensional computed tomography simulator and preliminary clinical evaluation

PURPOSE

We describe the conceptual structure and process of a fully integrated three-dimensional (3-D) computed tomography (CT) simulator and present a preliminary clinical and financial evaluation of our current system.

METHODS AND MATERIALS

This is a preliminary report on 117 patients treated with external beam radiation therapy alone on whom a 3-D simulation and treatment plan and delivery were carried out from July 1, 1992, through June 30, 1993. The elements of a fully integrated 3-D CT simulator were identified: (a) volumetric definition of tumor volume and patient anatomy obtained with a CT scanner, (b) virtual simulation for beam setup and digitally reconstructed radiographs, (c) 3-D treatment planning for volumetric dose computation and plan evaluation, (d) patient-marking device to outline portal on patient's skin, and (e) verification (physical) simulation to verify portal placement on the patient. Actual time-motion (time and effort) recording was made by each professional involved in the various steps of the 3-D simulation and treatment planning on computer-compatible forms. Data were correlated with the anatomic site of the primary tumor being planned. Cost accounting of revenues and operation of the CT simulator and the 3-D planning was carried out, and projected costs per examination, depending on case load, were generated.

RESULTS

Average time for CT volumetric simulation was 74 min without or 84 min with contrast material. Average times were 36 min for contouring of tumor/target volume and 44 min for normal anatomy, 78 min for treatment planning, 53 min for plan evaluation/optimization, and 58 min for verification simulation. There were significant variations in time and effort according to the specific anatomic location of the tumor. Portal marking of patient on the CT simulator was not consistently satisfactory, and this procedure was usually carried out on the physical simulator. Based on actual budgetary information, the cost of a volumetric CT simulation (separate from the 3-D treatment planning) showed that 1500 examinations per year (six per day in 250 working days) must be performed to make the operation of the device cost effective. The same financial projections for the entire 3-D planning process and verification yielded five plans per day. Some features were identified that will improve the use of the 3-D simulator, and solutions are offered to incorporate them in existing devices.

CONCLUSIONS

Commercially available CT simulators lack some elements that we believe are critical in a fully integrated 3-D CT simulator. Sophisticated 3-D simulation and treatment planning can be carried out in a significant number of patients at a reasonable cost. Time and effort and therefore cost vary according to the anatomic site of the tumor being planned and the number of procedures performed. Further efforts are necessary, with collaboration of radiation oncologists, physicists, and manufacturers, to develop more versatile and efficient 3-D CT simulators, and additional clinical experience is required to make this technology cost effective in standard radiation therapy of patients with cancer.

Impact of elapsed treatment time on outcome of external-beam radiation therapy for localized carcinoma of the prostate

PURPOSE

The purpose of this study was to evaluate the impact of elapsed treatment time in external-beam radiation therapy for localized prostate carcinoma.

MATERIALS AND METHODS

The medical records of 1083 patients with localized prostate carcinoma treated between 1970 and December 1999 with external irradiation alone were reviewed. Median follow-up was 6 years (range, 4-24 years). Since 1987, prostate-specific antigen levels were obtained in 687 patients before the initiation of radiation therapy, and all patients seen in follow-up had prostate-specific antigen determinations. There were 344 patients with T1c, 496 with T2, and 243 with T3 tumors. The elapsed treatment time was divided into < or = 7, 7.1-9, or > 9 weeks. Local tumor control was determined by rectal examination and cause-specific survival or prostate-specific antigen failure according to American Society of Therapeutic Radiology and Oncology consensus criteria. Because of dose-escalation studies, tumor dose levels ranged from 66-73.8 Gy, given in 1.8- to 2-Gy fractions.

RESULTS

In patients with stage T1c, local failure ranged from 0% to 10% with doses < or = 72 Gy with; elapsed treatment time had no impact. No pelvic failures were detected in 88 patients receiving doses > 72 Gy. In patients with T2 who received < or = 70 Gy, overall pelvic failure rate was 4% (12/306) in those with an elapsed treatment time of < or = 9 weeks, in contrast to 27% (12/44) for those with an elapsed treatment time > 9 weeks; at 10 years, patients with T2 tumors treated in > 9 weeks had a higher actuarial pelvic failure rate (35%), in contrast to 5% to 18% with shorter treatment times. For patients with T2 tumors who received 70-72 Gy, pelvic failure rate ranged from 0% to 32%, and there were no failures in 37 patients treated to higher doses. In patients with prostate-specific antigen values whose tumors were stage T1c, the chemical failure rate was 41% (60/147) with a tumor dose < 70 Gy, compared with 17% (4/24) in those who received higher doses. In patients with stage 2 disease who were treated with < 70 Gy, the chemical failure rate was 31%, and the rate was 12%-18% in those who received higher doses. In stage T3, the clinical pelvic failure rate ranged from 25% to 32% in the three elapsed time groups, and the chemical failure rate ranged from 48% to 69%, and there was no significant correlation with elapsed time or total irradiation dose. Cause-specific survival without chemical failure in patients with stage T1c disease at 10 years was 85%-90% in the three elapsed treatment time groups. In patients with stage T2 disease, the corresponding values were 80% and 90% for elapsed treatment times < 9 weeks, in contrast to 65% for patients treated > 9 weeks. In patients with stage T3 disease, cause-specific survival was about 60% in all elapsed treatment groups. There was no significant correlation of elapsed treatment time with urinary or rectal morbidity.

CONCLUSIONS

Patients treated with radiation therapy for stage T2 localized prostate carcinoma showed a greater incidence of pelvic and chemical failures and a lower cause-specific survival when elapsed treatment time was > 9 weeks in comparison with the failure and survival rates occurring with shorter times. Higher doses of irradiation (> 72 Gy) eliminate the influence of prolongation of treatment time on outcome.

Thoracic irradiation with or without levamisole (NSC #177023) in unresectable non-small cell carcinoma of the lung: a phase III randomized trial of the RTOG

A total of 285 patients with medically inoperable (RTOG Stage T1-2, N0-1) or unresectable (RTOG Stage T3, N0-1) non-small cell carcinoma of the lung were randomized by the Radiation Therapy Oncology Group (RTOG) to receive radiation therapy (6000 cGy total dose/6 weeks) plus levamisole (2.5 mg/kg twice weekly for 2 years or until tumor progression) or a placebo. One hundred twenty-nine evaluable patients were assigned to placebo and 131 to levamisole. This report is based on 260 (91%) eligible patients who started treatment and have adequate follow-up. Fifty percent of the patients in both treatment groups had Karnofsky scores of 90-100; 72% had squamous cell carcinoma, 12% adenocarcinoma, and 16% large cell undifferentiated carcinoma; 60% had RTOG Stage I or II primary tumors and 40% had Stage III (T3, N0-1) tumors. Complete regression of tumor was reported in 20% of the patients treated with levamisole and 36% of those receiving placebo. An additional 33% and 19%, respectively, had a partial response (trend test p = 0.08). Median survival was 9 months for patients treated with levamisole and 12 months for those on placebo (two-sided p less than 0.01); at 2 years, patients treated with levamisole had a 15% survival rate as compared to 24% in those receiving placebo. The cumulative proportion failing within the irradiated field with or without other sites of progression at 2 years was 30% in the levamisole group and 34% in the placebo patients. Median progression-free survival was 6 months for patients on levamisole and 7 months for those on placebo (overall two-sided p = 0.014); the estimated proportions progression-free at 2 years were 11% and 18%, respectively. The study showed no significant prolongation of survival, progression-free survival, or differences in patterns of failure in irradiated patients treated with levamisole compared with a placebo. Toxicity related to this immunoadjuvant was, in general, of moderate clinical importance. This study confirms a report by the Southeastern Cancer Study Group concluding that levamisole combined with definitive irradiation has no benefit in the treatment of unresectable non-small cell carcinoma of the lung.

Prognostic significance of endometrial extension from primary carcinoma of the uterinecervix

This is a retrospective analysis of 302 patients with histologically confirmed primary carcinoma of the cervix on whom a dilatation and curettage was performed during the initial workup. The prognostic significance of endometrial extension of the tumor was investigated. Four different types of specimen were identified: 1) endometrial extension of cervical carcinoma; 2) cervical carcinoma in the currettings only; 3) a mixture of normal endometrium and and epidermoid carcinoma in the curettings; 4) no cervical carcinoma noted (negative D&C). The patients were staged according to the FIGO classification. Patients with Stage I carcinoma and positive D&Cs showed significantly lower 3-5 year survival rates (50-60 percent), as opposed to those with D&C.

Radiation therapy in the management of carcinoma of the lung

Carcinoma of the lung is the most common cancer in men in the United States and a major cause of death. This is due to the inadequate techniques for screening of high-risk patients and for detection of the tumor in early stages, before distant dissemination occurs. Although some progress has been made in the past, particularly in improving the knowledge of natural history and pathological characteristics of the disease, and there are better indications for surgical treatment and irradiation and the effective use of cytotoxic agents in selected groups of patients, particularly those with small cell undifferentiated carcinoma, the mortality rate is still very high. A great deal of investigation remains to be done in carcinoma of the lung concerning the basic cell kinetics of the tumor and the optimal conditions for the use of surgery, irradiation, chemotherapy or combinations of these agents in the treatment of these patients before survival rates can be substantially improved. Since the most important factor in patient mortality is distant tumor dissemination, it must be stressed that parameters other than survival should be used to evaluate the effectiveness of irradiation, surgery or combinations in the control of local and regional bronchogenic carcinoma. These efforts should be intensified through properly designed clinical trials.

Irradiation in relapsing carcinoma of the prostate

BACKGROUND

Radiation therapy plays a major role in the management of patients with either locally recurrent or metastatic carcinoma of the prostate.

RESULTS

In 23 patients with isolated postprostatectomy local recurrences treated with doses of 60-65 Gy, 17 (74%) had tumor control, and 45% survived relapse-free for 5 years after treatment of the recurrence. Pelvic irradiation has been used to treat patients with elevated prostate-specific antigen (PSA) levels after radical prostatectomy. This was tried, and 17 of 24 patients (70%) showed a significant decrease in PSA levels after irradiation, in five without subsequent elevation. Two of the seven patients with elevated PSA levels later had distant metastases. Local irradiation has been reported to yield excellent relief of symptoms in 100% of patients with hematuria, 80% with urinary outflow obstruction, and 50-70% with ureteral obstruction or pelvic pain secondary to locally advanced prostatic carcinoma. Reirradiation, particularly with brachytherapy (in preliminary studies combined with hyperthermia) has been used in the management of postirradiation prostatic recurrences with satisfactory tumor regression in approximately 75% of patients. The Radiation Therapy Oncology Group (RTOG) reported on the palliative effects of external irradiation on patients with bony metastasis. Approximately 54% of such patients had complete relief, and 29% had partial relief of bone pain. However, the retreatment rate of the bony metastasis was lower in the patients receiving higher doses. In a RTOG protocol in which all patients received local irradiation for osseous metastases, 77 were randomized to receive elective hemibody irradiation and 69, local treatment only. The frequency of additional treatment at 1 year was lower in the hemibody irradiation group (54% versus 78%). Occasionally, brain, mediastinal, or liver metastasis can be treated with irradiation. Radioactive phosphorus-32 or strontium-89 has been administered for disseminated bony metastasis with improvement of bone pain in approximately 70-80% of treated patients.

CONCLUSION

The role of irradiation in the treatment of spinal cord compression is discussed. Significant improvement of neurologic function has been reported in 36-60% of the patients, depending on severity of deficit and promptness in instituting emergency treatment.

Cost benefit of emerging technology in localized carcinoma of the prostate

PURPOSE

In a health care environment strongly concerned with cost containment, cost-benefit studies of new technology must include analyses of loco-regional tumor control, morbidity, impact on quality of life, and financial considerations.

METHODS AND MATERIALS

This nonrandomized study analyzes 124 patients treated with three-dimensional conformal radiation therapy (3D CRT) and 153 with standard irradiation (SRT) between January 1992 and December 1995, for histologically proven adenocarcinoma of prostate, clinical Stage T1 or T2. Mean follow-up is 1.4 years. Three-dimensional CRT consisted of six or seven coplanar oblique and lateral and, in some patients, AP fields designed to treat the prostate with a 1 to 1.7 cm margin. SRT consisted of 120 degrees bilateral arc rotation. Total doses to prostate were 67 to 70 Gy when pelvic lymph nodes were irradiated or 68.4 to 73.8 Gy when prostatic volume only was treated; dose per fraction was 1.8 Gy. Patients were interviewed weekly for severity of 12 acute intestinal and urinary pelvic irradiation side effects (0 to 4+ grading). Time and effort for 3D RTP and daily treatment with 3D CRT and SRT were recorded. Dose-volume histograms (DVHs) were calculated for gross tumor volume, planning target volume, bladder, and rectum. Actual reimbursement to the hospital and university was determined for 41 3D CRT, 43 SRT, and 40 radical prostatectomy patients treated during the same period.

RESULTS

Average treatment planning times (in minutes) were: 101 for 3D conformal therapy simulation, 66 for contouring of target volume and sensitive structures, 55 for virtual simulation, 39 for plan preparation and documentation, 65 for physical simulation, and 20 for approval of treatment plan. Daily mean treatment times were 19 min for 3D CRT with Cerrobend blocking, 16 with multileaf collimation, and 10 with bilateral arc rotation. Dosimetric analysis (DVHs) showed a reduction of 50% in volume of bladder or rectum receiving doses higher than 65 Gy. Acute side effects included dysuria, moderate difficulty in urinating, and nocturia in 25-39% of both SRT and CRT patients; loose stools or diarrhea in 5-12% of 3D CRT and 16-22% of SRT patients; moderate proctitis in 3% of 3D CRT and 12% of SRT patients (p = 0.01). Chemical disease-free survival (prostate-specific antigen < or =2 ng/ml) at 3 years was 90% with 3D CRT and 80% with SRT (p = 0.01). Average initial treatment reimbursements were $13,823 (3D CRT), $10,864 (SRT), and $12,250 (radical prostatectomy). Average total treatment reimbursement and projected cost of management of initial therapy failures per patients were $15,173, $16,264, and $16,405, respectively.

CONCLUSIONS

Three-dimensional CRT irradiated less bladder and rectum volume than SRT; CRT initial reimbursement was 28% higher than SRT and 12% higher than radical prostatectomy. Because of projected better local tumor control, average total cost of treating a patient with 3D CRT or radical prostatectomy is equivalent to cost of SRT. Treatment morbidity was lower with 3D CRT. Our findings reflect an overall benefit with 3D CRT as a new promising technology in treatment of localized prostate cancer. Dose-escalation studies may enhance its efficacy and cost benefit.

Design of an afterloading vaginal applicator (MIRALVA)

A vaginal applicator was designed and constructed that incorporates two ovoid sources and a central tandem which can be utilized to treat the entire vagina (alone or in combination with the uterine cervix). The average surface dose rate around the 2 cm ovoids is 120 cGy/hr and in the 2.5 cm diameter vaginal cylinder about 100 cGy/hr with usual loading of 20 mg Ra eq 137-Cs sources in the ovoids and 10-15 mg Ra eq 137-Cs sources in the cylinder. The applicator has vaginal apex caps and additional cylinder sleeves that allow for increased dimensions. The tandem in the uterus can be utilized when clinically indicated using standard loadings, depending on the depth of the uterus (20-10-10 or 20-10 mg Ra eq). When the tandem and vaginal cylinder are utilized the strength of the sources in the ovoids should be 15 mg Ra eq. The vaginal cylinder or uterine tandem never carry an active source at the level of the ovoids. Thermoluminescent dosimetry measurements throughout the surface of the applicator showed close agreement with the computer dose calculations (within +/- 2%). The acronym MIRALVA describes the device (Mallinckrodt Institute of Radiology Afterloading Vaginal Applicator).

Chemical disease-free survival in localized carcinoma of prostate treated with external beam irradiation: comparison of American Society of Therapeutic Radiology and Oncology Consensus or 1 ng/mL as endpoint

PURPOSE

To compare postirradiation biochemical disease-free survival using the American Society of Therapeutic Radiology and Oncology (ASTRO) Consensus or elevation of postirradiation prostate-specific antigen (PSA) level beyond 1 ng/mL as an endpoint and correlate chemical failure with subsequent appearance of clinically detected local recurrence or distant metastasis.

METHODS AND MATERIALS

Records of 466 patients with histologically confirmed adenocarcinoma of the prostate treated with irradiation alone between January 1987 and December 1995 were analyzed; 339 patients were treated with bilateral 120 degrees arc rotation and, starting in 1992, 117 with three-dimensional conformal irradiation. Doses were 68--77 Gy in 1.8 to 2 Gy daily fractions. Minimum follow-up is 4 years (mean, 5.5 years; maximum, 9.6 years). A chemical failure was recorded using the ASTRO Consensus or when postirradiation PSA level exceeded 1 ng/mL at any time. Clinical failures were determined by rectal examination, radiographic studies, and, when clinically indicated, biopsy.

RESULTS

Six-year chemical disease-free survival rates using the ASTRO Consensus according to pretreatment PSA level for T1 tumors were: < or = 4 ng/mL, 100%; 4.1--20 ng/mL, 80%; and > 20 ng/mL, 50%. For T2 tumors the rates were: < or = 4 ng/mL, 91%; 4.1--10 ng/mL, 81%; 10.1--20 ng/mL, 55%; 20.1--40 ng/mL, 63%; and > 40 ng/mL, 46%. When postirradiation PSA levels higher than 1 ng/mL were used, the corresponding 6-year chemical disease-free survival rates for T1 tumors were 92% for pretreatment PSA levels of < or = 4 ng/mL, 58--60% for levels of 4.1--20 ng/mL, and 30% for levels > 20 ng/mL. For T2 tumors, the 6-year chemical disease-free survival rates were 78% in patients with pretreatment PSA levels of 4--10 ng/mL, 45% for 10.1--40 ng/mL, and 25% for > 40 ng/mL. Of 167 patients with T1 tumors, 30 (18%) developed a chemical failure, 97% within 5 years from completion of radiation therapy; no patient has developed a local recurrence or distant metastasis. In patients with T2 tumors, overall 45 of 236 (19%) had chemical failure, 94% within 5 years of completion of radiation therapy; 4% have developed a local recurrence, and 10%, distant metastasis. In patients with T3 tumors, overall, 24 of 65 (37%) developed a chemical failure, 100% within 3.5 years from completion of radiation therapy; 4% of these patients developed a local recurrence within 2 years, and 12% developed distant metastasis within 4 years of completion of irradiation. The average time to clinical appearance of local recurrence or distant metastasis after a chemical failure was detected was 5 years and 3 years, respectively.

CONCLUSION

There was a close correlation between the postirradiation nadir PSA and subsequent development of a chemical failure. Except for patients with T1 tumors and pretreatment PSA of 4.1--20 ng/mL, there is good agreement in 6-year chemical disease-free survival using the ASTRO Consensus or PSA elevations above 1 ng/mL as an endpoint. Although the ASTRO Consensus tends to give a higher percentage of chemical disease-free survival in most groups, the differences with longer follow-up are not statistically significant (p > 0.05). It is important to follow these patients for at least 10 years to better assess the significance of and the relationship between chemical and clinical failures.

Conservation therapy in T1-T2 breast cancer: past, current issues, and future challenges and opportunities

PURPOSE

To assess the significance of patient age, race, tumor-related prognostic parameters, status of surgical excision margins, and irradiation boost on incidence of ipsilateral breast relapse, and to review current issues in the management of T1-T2 breast cancer patients with conservation therapy.

MATERIALS AND METHODS

Records of 1037 patients with histologically confirmed stage T1 and 308 patients with T2 carcinoma of the breast treated with breast conservation therapy from January 1970 through December 1997 were prospectively registered and evaluated. The mean follow-up for surviving patients was 6.6 years (range, 4-30 years), with a minimum follow up of 4 years for all patients.

RESULTS

There were 78 ipsilateral breast relapses (IBRs); the actuarial 10-year incidence of IBR was 7% for T1 and 11% for T2 tumors. In patients 40 years of age or younger, four of 24 (17%) with extensive intraductal component developed an ipsilateral breast relapse, compared with six of 80 (8%) without extensive intraductal component, in contrast to eight of 159 (5%) and 33 of 776 (4%) in postmenopausal patients with or without extensive intraductal component, respectively. In patients with T2 tumors, two of eight (25%) women 40 years or younger with extensive intraductal component, and seven of 50 (14%) without extensive intraductal component developed ipsilateral breast relapse. The corresponding values for the patients older than 40 years were five of 48 (10%) and 13 of 202 (6%), respectively. The incidences of ipsilateral breast relapses, correlated with status of surgical margins after re-excision in T1 tumors, were one of 30 (3.3%) for positive, no relapses in 40 patients with close margins, 16 of 438 (3.6%) for negative, and 18 of 196 (9%) for undetermined margins. In the patients with T2 tumors, ipsilateral breast relapses occurred in two of 16 patients (12.5%) with positive margins, one of 16 (6%) with close, seven of 105 (6.6%)with negative, and four of 68 (5.9%) with undetermined margins (differences not statistically significant). In patients with T1 tumors, negative margins, the 10-year relapse rate was the same (8%) in 559 to whom a boost was administered and in 66 without a boost. In patients with positive margins, the relapse rate was 4% in 215 receiving a boost (18-20 Gy) and 33% (two of six) without a boost. In patients with T2 tumors and negative margins, the rate of ipsilateral breast relapses in 16 patients to whom no boost was given was 12%, as opposed to 10% in 143 patients who received a boost. However, with T2 tumors and close or positive margins, the IBR rate at 10 years was 12% in 81 given a boost, in contrast to 40% (2 of 5) without a boost. In T1 tumors, the breast failure rate was two of 53 (3.7%) in women < or = 40 years receiving chemotherapy and eight of 51 (15.6%) without chemotherapy. For T2 tumors, the corresponding values were seven of 39 (17%) and two of 19 (10.5%), respectively. In women 40 years or younger with T1 tumors receiving hormones or not, the ipsilateral breast relapse rate was two of 19 (10.5%) and eight of 85 (9.4%), respectively; in the older than 40 years group, the corresponding values were six of 377 (1.6%) and 35 of 558 (6.2%). In the patients with T2 tumors, ipsilateral breast relapse rates were not statistically different in the various groups. On multivariate analysis, only age and adjuvant therapy were significant factors predictive of ipsilateral breast relapse.

CONCLUSIONS

Surgical excision margins status following adequate doses of radiation therapy was not a predictor of ipsilateral breast relapse. In patients younger than 40 years of age with extensive intraductal component, a somewhat higher breast relapse rate was noted but not enough to preclude breast conservation therapy. A boost of irradiation did not have a significant impact in the incidence of ipsilateral breast relapse in patients with negative margins, but it was of benefit to those with close or positive margins. Close attention to surgical margin status and delivery of higher doses of irradiation to the tumor excision site in patients with close or positive surgical margins will decrease the probability of breast relapses.