Transperineal percutaneous iridium-192 interstitial template implant of the prostate: results and complications in 321 patients

Braquiterapia de alta taxa de dose no tratamento do carcinoma da próstata: análise da toxicidade aguda e do comportamento bioquímico

OBJETIVO: Analisar a resposta bioquímica nas variáveis volume prostático, valor do antígeno prostático específico (PSA), escores de Gleason, estádio, risco da doença e hormonioterapia. MATERIAIS E MÉTODOS: No período de fevereiro de 1998 a julho de 2001, 46 pacientes com câncer de próstata foram tratados com radioterapia, numa combinação de teleterapia e braquiterapia de alta taxa de dose (BATD). A idade variou de 51 a 79 anos (média de 66,4 anos). O estádio T1c foi o mais freqüente: 30 (65%). O escore de Gleason era abaixo de 7 em 78% dos pacientes. O PSA variou de 3,4 a 33,3, estando abaixo de 10 em 39% das vezes. O volume prostático médio foi de 32,3 cc. Um total de 28% dos pacientes recebeu hormonioterapia. A dose de teleterapia variou de 45 a 50,4 Gy, associada a quatro frações de BATD de 4 Gy. RESULTADOS: O seguimento variou de 6 a 43 meses. Quatro pacientes perderam seguimento e quatro morreram (um por doença). Dos 39 pacientes analisados, 76% apresentaram PSA menor que 1,5. Nenhuma das variáveis analisadas foi estatisticamente significante (p > 0,05) com relação ao controle bioquímico. CONCLUSÃO: A utilização de BATD foi eficiente no tratamento do câncer de próstata e, neste estudo, as variáveis consideradas como fatores prognósticos não interferiram no controle bioquímico.

High-dose-rate brachytherapy in the treatment of carcinoma of the prostate

BACKGROUND

Although radical prostatectomy for localized disease is considered as a standard of care, external-beam radiotherapy and brachytherapy are equally effective. We report on the technique and preliminary results of high-dose-rate (HDR) brachytherapy using a temporary iridium-192 implant technique.

METHODS

The authors reviewed the literature on the techniques, treatment protocols, and results of HDR brachytherapy in the treatment of carcinoma of the prostate, and they report their own protocols, technique, and results.

RESULTS

The combination of HDR brachytherapy and external irradiation has been well tolerated by all 200 patients in our series, with less than 3% grade 3 late complications and with 95% PSA relapse-free survival with a median follow-up of 24 months.

CONCLUSIONS

HDR brachytherapy may be the most conformal type of irradiation in the treatment of carcinoma of the prostate regardless of tumor size, anatomical distortion, and organ mobility.

Long-term results of treatment for prostate carcinoma by staging pelvic lymph node dissection and definitive irradiation using low-dose rate temporary iridium-192 interstitial implant and external beam radiotherapy

BACKGROUND

The objective of this study was to evaluate long-term treatment outcome of definitive irradiation by using temporary interstitial implant and limited dose of external beam radiotherapy in treatment of localized prostate carcinoma.

METHODS

In total, 536 patients with biopsy-proven adenocarcinoma of the prostate, classification T1-T3, underwent staging pelvic lymph node dissection and brachytherapy delivering an average tumor dose of 30 grays (Gy), supplemented by external beam radiation therapy for an additional dose of 36 Gy delivered over 4 weeks. One hundred of 536 (18%) patients had pathologic D1 disease. A total of 181 patients had undergone transurethral prostatectomy before the treatment. Repeat prostate biopsy was performed on 132 patients 18 or more months after treatment. None of the patients received neoadjuvant or adjuvant hormone therapy.

RESULTS

Cumulative disease free survival (DFS) including biochemical DFS at 10 and 15 years for classification T1B,C was 78% and 72%; for T2A, 78% and 78%; for T2B,C, 68% and 66%; and for T3A-C, 45% and 45%, respectively. Cause specific survival for the entire group at 10 and 15 years was 89% and 87%, respectively. Severe complications occurred only in the early developmental phase of the study.

CONCLUSIONS

In univariate analysis, the clinical stage, histologic grade, pretreatment PSA level, lymph node status, and results of repeat posttreatment biopsy were all independently significant prognostic factors. However, the authors' study indicates that in multivariate analysis, only two factors emerged with statistical significance-the status of pelvic lymph nodes and the results of posttreatment biopsy. This signifies the importance of local tumor control to achieve ultimate cure and the importance of assessment of pelvic lymph nodes before definitive local therapy other than radical prostatectomy, especially in the high-risk group.

[Prostatic brachytherapy: an alternative therapy. Review of the literature]

Radical prostatectomy remains the 'golden standard' therapy for localized prostate carcinoma for patients with a survival rate of more than ten years. However, because of the complications inherent in this surgical procedure, prostatectomy is presently increasingly challenged by various radiotherapy procedures. In the last decade, more sophisticated conformal therapy techniques have been proposed for prostate cancer patients. In parallel, for highly selected patients, brachytherapy is being promoted by an increasing number of medical centers. In fact, brachytherapy techniques for prostate cancers can be traced back to 1911, but recently developed techniques offer reliability and reproducibility, with satisfactory results in terms of tumor control and reduced toxicity, in selected patients. We present here the different techniques that are available today in prostate cancer brachytherapy.

Have complication rates decreased after treatment for localized prostate cancer?

PURPOSE

The American Urological Association Prostate Cancer Clinical Guidelines Panel reviewed 12,501 publications on prostate cancer from 1955 to 1992 to determine whether the complication rates of external beam radiation therapy, interstitial radiotherapy and radical prostatectomy have decreased.

MATERIALS AND METHODS

Complications reported in at least 6 series, study duration and sample sizes were extracted. Year specific study weighted mean patient ages and complication rates were computed. Regression analysis was performed of the study year on weighted mean patient age and complication rate.

RESULTS

Study year had a significant effect on mean patient age and rate of the majority of complications examined. Data indicated a gradual increase in study patient age and a simultaneous decrease in complications from 1960 to 1990.

CONCLUSIONS

Complication rates in the treatment of localized prostate cancer have decreased during the last 20 to 40 years. This decrease occurred despite evidence that the average age of treated patients had increased during the same period.

High dose rate brachytherapy in the treatment of prostate cancer

Because the HDR brachytherapy treatments are delivered within minutes and on an outpatient basis, HDR brachytherapy is very well tolerated by patients and offers complete radiation safety. Published studies2, 11, 12, 13, 16, 17, 18, 22, 24, 25 have shown high local clinical and biochemical control rates. Chronic complications have been acceptably low. Very low rates of urinary incontinence and high sexual potency rates have been reported. Gastrointestinal morbidity has been minimal. The development of Ir-192 HDR afterloading brachytherapy and refinements in the dosimetry have ushered in a new era in prostate brachytherapy. The control of the radiation dose and the ability to shape the radiation treatment envelope using a stepping source have allowed a giant step forward in radiation oncology technology. It is now possible to deliver tumoricidal doses of radiation conformally to the prostate while minimizing the dose to the bladder, urethra, and rectum. At present, HDR afterloaded brachytherapy is the optimal whole-organ and tumor-specific conformal radiation therapy for prostate cancer.

High-dose rate interstitial with external beam irradiation for localized prostate cancer--results of a prospective trial

PURPOSE

A prospective phase II trial was carried out to test the feasibility and effectiveness of a combined interstitial with external beam radiotherapy approach for localized prostate cancer.

MATERIALS AND METHODS

Between October 1992 and December 1994, 82 evaluable patients were treated. T2 and T3 tumours, according to the AJCC classification system of 1992, were found in 21 and 61 cases, respectively. The median follow-up was 24 months; three patients were lost during follow-up. All of the patients were pathologically proven to be node-negative by laparoscopic node dissection of the fossa obturatoria region. A dose of 9 Gy a week was prescribed during the first and second weeks of treatment (10 Gy each week from October 1992 to December 1993) interstitially with high-dose rate Iridium-192 brachytherapy to the prostate and tumour extension beyond the capsule. External beam four-field box irradiation was then given to the prostate to a dose of 45 Gy/25 fractions (40 Gy/20 fractions from October 1992 to December 1993).

RESULTS

Before starting treatment, a PSA value of > or =10 ng/ml was found in 64.6% (53/82) of patients with a median PSA of 14.0 ng/ml. The median PSA 3, 12 and 24 months after completion of therapy was 1.20, 0.78 and 0.70 ng/ml, respectively. The PSA value was < 1.0 ng/ ml in 52.9% of patients at 2 years. Negative punch biopsies 12 and 24 months after therapy were observed in 69.8% (44/63) and 73. 1% (38/ 52) of patients, respectively. A positive biopsy combined with a PSA value of > 1.0 ng/ml was considered as local failure. The local tumour control rate was 79.5% at 2 years. Acute side-effects were not increased relative to external beam irradiation alone. Severe side-effects were observed in three patients (two of the three patients had additional risk factors (colitis ulcerosa and diabetes mellitus)); they developed rectourethral fistulae requiring colostomy after biopsies from the anterior rectal wall.

CONCLUSION

The described method is feasible and well tolerable. The three complications observed were not caused by irradiation alone. Biopsies from the anterior rectal wall after definitive high-dose radiotherapy for prostate cancer have to be seen as obsolete. The rate of negative prostate biopsies of 73.1% after 24 months represents an encouraging result.

Interstitial implantation techniques in prostate cancer

Brachytherapy is a radiotherapeutic technique that allows the physician to implant radioactive isotopes into a body cavity or directly into tissue. Different radioisotopes have unique characteristics that the brachytherapist may utilize for a particular situation. The use of brachytherapy is part of standard radiation oncology practice in gynecological and head and neck cancer management. The prostate is approachable for interstitial implantation due to its close proximity to the perineum. Over 20 years ago, primitive methods of brachytherapy were utilized in the treatment of prostate cancer. However, poor results due to inconsistency in achieving adequate coverage of the entire prostate and poor patient selection caused this treatment modality to fall out of favor. Technological advances over the last decade have restored attention to brachytherapy for prostate cancer. Particularly important has been the development of transrectal ultrasound, new radioisotopes such as palladium-103, computer tomography, computerized dosimetry systems, and earlier diagnosis. Modern interstitial implantation utilizing transperineal template and transrectal ultrasound guidance has resulted in improved consistency in radiation dose delivery to the entire prostate. Early results are encouraging in terms of the relatively low morbidity of the procedure, improved local control rates, and biochemical progression free survival. This has resulted in an outpatient treatment that has high patient acceptance.

Should brachytherapy be considered a therapeutic option in localized prostate cancer?

Contemporary prostate brachytherapy incorporates advances in computer analysis, imaging technology, and delivery apparatus, allowing exacting and reproducible results compared with historical approaches. The advances permit brachytherapy to be performed on a cost-effective, outpatient basis with low morbidity in the appropriately selected patient. Although unsettled questions remain regarding dosimetric issues, long-term outcomes, and morbidity, the weight of evidence to date appears to support the use of brachytherapy in selected patients. Brachytherapy may be considered a therapeutic option: as monotherapy for early-stage disease and also a boost following moderate doses of external beam irradiation for locally advanced disease.

Conformal prostate brachytherapy: initial experience of a phase I/II dose-escalating trial

PURPOSE

To improve treatment results on prostatic adenocarcinoma, conformal radiation therapy (CRT) has been used. Two major drawbacks of external CRT are: (a) internal organ motion/daily set-up variations, and (b) exclusion of several patients for CRT based on poor geometrical relationships as identified by three dimensional (3D) treatment planning. To overcome the above problems, we began the first prospective Phase I/II dose-escalating clinical trial of conformal brachytherapy (CB) and concurrent external beam irradiation.

METHODS AND MATERIALS

Fifty-nine patients with T2b-T3c prostatic adenocarcinoma received 176 transperineal ultrasound-guided conformal high-dose rate (HDR) boost implants. All patients received concomitant external beam pelvic irradiation. Dose escalation of the three HDR-CB fractions proceeded as follows: 5.5 Gy (30 patients), 6 Gy (20 patients), and 6.5 Gy (9 patients). The CB dose was prescribed to the prostate contour as outlined using an online biplanar transrectal ultrasound probe. The urethra, anterior rectal wall, and prostate boundaries were identified individually and outlined at 5 mm intervals from the base to the apex of the gland. The CB using real-time ultrasound guidance with interactive online isodose distributions was performed on an outpatient basis. As needles were placed into the prostate, corrections for prostate displacement were recorded and the isodose distributions were recalculated to represent the new relationship between the needles, prostate, and normal structures. No computerized tomography (CT) planning or implant preplanning was required.

RESULTS

No patient was rejected based on poor geometrical relation of pelvic structures. In every implant performed, prostate displacement was noted. Craniocaudal motion of the gland ranged from 0.5-2.0 cm (mean = 1.0 cm), whereas lateral displacement was 0.1-0.4 cm. With the interactive online planning system, organ motion was immediately detected, accounted for, and corrected prior to each HDR treatment. The rectal dose has ranged from 45 to 87%, and the urethral dose from 97 to 112% of the prostate dose. It is significant to note that operator dependence has been completely removed because the interactive online planning system uniformly guides the physicians.

CONCLUSIONS

With ultrasound guidance and the interactive online dosimetry system, organ motion (as compared to external beam) is insignificant because it can be corrected during the procedure without increasing target volume margins. Common pitfalls of brachytherapy, including operator dependence and difficulty with reproducibility, have been eliminated with the intraoperative online planning system.

Ultrasound-guided high dose rate conformal brachytherapy boost in prostate cancer: treatment description and preliminary results of a phase I/II clinical trial

PURPOSE

To improve results for locally advanced prostate cancer, a prospective clinical trial of concurrent external beam irradiation and fractionated iridium-192 (Ir-192) high dose rate (HDR) conformal boost brachytherapy was initiated.

METHODS AND MATERIALS

Between November 1991 and February 1994, 99 implants were performed on 33 patients with prostatic adenocarcinoma at William Beaumont Hospital. Using AJCC staging criteria, 9 patients had T2b tumors, 17 patients had T2c tumors, and 7 patients had T3 disease. Patients were treated with (a) 45.6 Gy whole pelvis external irradiation and (b) three HDR fractions of 5.5 Gy each (18 patients) or 6 Gy each (15 patients) to the prostate. Transperineal needle implants using real-time ultrasound guidance with interactive on-line isodose distributions were performed on an outpatient basis during weeks 1, 2, and 3 of external irradiation. Acute toxicity was scored using the Radiation Therapy Oncology Group (RTOG) morbidity grading system.

RESULTS

This technique of concurrent external pelvic irradiation and conformal HDR brachytherapy was well tolerated. No significant intraoperative or perioperative complications occurred. Three patients (9%) experienced Grade 3 acute toxicity (two dysuria and one diarrhea). All toxicities were otherwise Grades 1 or 2 and were primarily as expected from pelvic external irradiation. Persistent implant-related toxicities included Grades 1-2 perineal pain (12%) and hematospermia (15%). Median follow-up time was 13 months. Serum prostatic-specific antigen (PSA) levels normalized in 91% of patients (29 out of 32) within 1-14 months (median 2.8 months) after irradiation. PSA levels were progressively decreasing in the other three patients at last measurement. Prospectively planned prostatic rebiopsies done at 18 months in the first 10 patients were negative in 9 out of 10 (90%).

CONCLUSIONS

Acute toxicity has been acceptable with this unique approach using conformal high dose rate Ir-192 boost brachytherapy with concurrent external irradiation. The initial tumor response as assessed by serial PSA measurement and rebiopsy is extremely encouraging. Dose escalation will proceed in accordance with the protocol guidelines. Further patient accrual and longer follow-up will allow comparison to other techniques.

Ultrasound guided placement of transperineal prostatic afterloading catheters

PURPOSE

A new method of performing temporary prostate brachytherapy which does not require an open laparotomy is described.

METHODS AND MATERIALS

This procedure allows dynamic visualization of the placement of 13-gauge (I-125) or 17-gauge (Ir-192) afterloading catheters into the prostate gland via saggital ultrasound imaging. The image enables visualization of the entire path of the catheter as well as cephalad gland movement. The prostate gland, seminal vesicles, bladder neck, urethra, and rectum are easily identified and implanted, if desired, during the procedure. This procedure has been used in 34 patients as an interstitial boost for locally advanced (T2b, T3) prostatic carcinoma following external beam therapy as a means to safely deliver higher doses to the gland. Another eight patients have undergone this procedure as salvage following failure of prior radical prostatectomy or external beam therapy.

RESULTS

Very customized dosimetry has been obtained using this technique as a result of the optimal catheter placement achieved under ultrasound guidance, particularly with I-125. Although it is too early to evaluate efficacy, the procedure has been well tolerated and is associated with minimal morbidity to date.

CONCLUSION

This new procedure seems to be an excellent means of safe delivery of higher doses to the gland compared to conventional external beam therapy. Due to the ability to cover the seminal vesicles as well as the afterloading nature of this procedure, a more customized implant is obtained relative to most permanent techniques, and open laparotomy is not required.