You are here: Information for Healthcare Professionals

Prostate brachytherapy

This section aims to provide background information on low dose-rate (LDR) brachytherapy permanent seed implantation, what it is, how it is done, patient-selection criteria and its clinical benefits.

Radioactive seed implantation (LDR brachytherapy)

LDR brachytherapy is an increasingly popular alternative to radical surgery and radiotherapy for many patients with early, localised prostate cancer. It involves the transperineal placement of radioactive seeds directly into the prostate under ultrasound guidance, and aims to deliver a high dose of radiation to the prostate (145 Gray (Gy)).

The procedure can be carried out as a day case, or involve one overnight stay, and many patients experience no immediate morbidity and can continue to work or travel soon after the procedure. To help patients visualize the procedure and to distinguish it from major surgery - such as radical prostatectomy - the Prostate Brachytherapy Advisory Group has introduced a new descriptive for the procedure - pinhole surgery. It is hoped that use of this terminology will more accurately reflect the non-invasive nature of LDR brachytherapy and raise awareness of this NICE-approved treatment option.

As detailed below, the benefits of LDR brachytherapy (permanent seed implantation) far outweigh any disadvantages, and it has, therefore, become a very attractive option for those seeking to minimise the inconvenience associated with other radical treatments. The method is outlined in Figure 1 below.

Figure 1 — Method of radioactive seed implantation.

Advantages of LDR brachytherapy (permanent seed implantation)

  • Avoids the physical trauma of a major surgical procedure
  • An outpatient procedure requiring minimal hospitalisation
  • Allows for precise placement of the seeds offering more tailored treatment for the patient.
  • Procedure causes minimal bleeding
  • Has relatively few long-term side-effects
  • Allows relatively quick recovery and return to normal activity for the patient
  • One-off, minimally invasive procedure
  • Well tolerated in the majority of patients with localised disease
  • Maintains sexual potency in many patients
  • Has produced good long-term clinical outcomes
  • Demonstrated cost-effective treatment option

Disadvantages of LDR brachytherapy (seed implantation)

  • Patients can experience transient urinary irritative symptoms
  • Close contact with small children and pregnant women should be avoided in the first two-months following treatment

Typical seed-implantation technique

Brachytherapy, using radioactive seeds of iodine-125 or palladium-103 implanted into the prostate through fine needles, does not require a surgical incision and is performed on an outpatient, or short inpatient, basis, under general or spinal (epidural) anaesthesia. The doctor locates and views the prostate using transrectal ultrasound. The ultrasound images are imported into a computer and the position of the needles and seeds is planned. The doctor then inserts the needles through the skin between the scrotum and rectum and guides them into the prostate using the ultrasound images. The optimisation of placement of these sources is performed using computer-assisted dosimetry software either before or during the procedure. After the procedure the dosimetric parameters are verified using computerised dosimetry. The number of needles varies from patient to patient, but usually between 15 and 25 are used. Through these needles, about 100 (usually between 70 and 150) radioactive seeds are inserted into the prostate. The computer can update the dose distribution within the prostate resulting from the seed implantation. This allows the doctor to modify the position of subsequent seed placement. The needles are then removed. The seeds remain in the prostate permanantly, slowly giving out radiation until they are no longer radioactive. This period is about six months for iodine seeds and two months for palladium seeds. During this time, the patient must observe minimal radiation precautions. Travel and contact with adults are not restricted; however, small children and pregnant women should not be in direct contact with the patient for prolonged periods during these two months. Sexual intercourse can usually be resumed after about one month.

After the implant, the patient goes to the recovery room for a few hours. X-rays and CT scans are usually then undertaken, and the Foley catheter is removed. The patient goes home after recovering from the anaesthesia. Most patients are able to resume their normal activities within a few days.

Follow-up

The patient returns for an examination after 4 — 6 weeks, at 6 months and then on a yearly basis. A digital rectal exam is performed and prostate-specific antigen (PSA) levels are checked.

Variations in brachytherapy technique

Two-stage technique (Seattle approach)

The original technique, a 'two-stage' procedure, requires two hospital visits, the first for a pre-implant planning session, followed 2 — 4 weeks later by the second at which the implant is carried out. This technique, popularly known as the 'Seattle technique', was introduced in the late 1980s by Grimm and Blasko in Seattle. It is the technique most commonly used in the USA and the UK and has excellent disease-free survival data at 15 years, with outcomes that are comparable to surgery.

For further information see Key Publications

Modern brachytherapy techniques use advances in ultrasound imaging, computer hardware and software development to provide implants under real-time ultrasound guidance coupled with a dynamic assessment of the implant. It is now possible to carry out brachytherapy as a single-visit/day-case procedure.

Single-visit intra-operative dynamic prostate brachytherapy (the Potters' approach)

Louis Potters, of the New York Prostate Institute, developed his intra-operative dynamic approach while working at Memorial Sloane Kettering Cancer Centre. It makes use of the principle of inverse treatment planning and uses modern hardware and software developments to deliver a dynamic real-time implant with intra-operative dosimetry. It affords a control and flexibility for seed placement not previously available. This allows optimisation of the dosimetry to maximise treatment of the prostate while minimising the dosage to the urethra and the rectum.

The link below gives a more detailed explanation and visualisation of the Potters' approach as used at Guy's and St Thomas' Hospital and the Cromwell Hospital, London.

document type iconPotters technique

document type iconBrachytherapy vs surgery Guy's and St Thomas' Foundation Trust, London

Other variations

Some treatment can also include the addition of 3 — 5 weeks of external beam radiation and/or hormone treatments in addition to brachytherapy in selected patients. It is also possible to use 2 — 4 high dose-rate (HDR) brachytherapy treatments along with 3 — 5 weeks of external beam radiation.

Details on these techniques and the associated outcomes can be seen in the attached presentations, and within Section 2.4, UK Brachytherapy Centres.

Patient selection

The EAU/ESTRO/EORTC (European Association of Urology/European Society for Therapeutic Radiology and Oncology/European Organisation for Research and Treatment of Cancer) guidelines published in 2000, gave the patient-selection criteria for brachytherapy monotherapy shown in Table 1 for patients with localised disease. It should be noted that the risk groups described in the European guidelines (do well, fair and do poorly) correspond to the low-, intermediate- and high-risk groups described in most US papers.

Table 1 — Indication for prostate brachytherapy monotherapy1

Recommended
Do well
Optional
Fair
Investigational
Do poorly
PSA (ng/ml)<1010 — 20>20
Gleason score5 — 678 — 10
StageT1c — T2aT2b — T2cT3
IPSSa0 — 89 — 19>20
Prostate volume (g)<4040 — 60>60
Qmax ml/sb>1515 — 10 <10
Residual volume (ml)>200

IPSSa: International Prostate Symptom Score.

Qmax ml/sb: urinary flow rate.

The following three tables indicate the suitability of patients with different parameters for different treatment options and are reproduced with the permission of a leading brachytherapy centre, the Prostate Cancer Centre, Guildford . It should be noted that the best available medical evidence would suggest that there is no discernable difference in the cure rates for patients with similar risk prostate cancer treated either by radical prostatectomy, brachytherapy or conformal beam radiotherapy (the latest machines allowing radiation doses of 72Gy or more to be given). Also indicated is the likelihood of side effects occurring with a particular treatment option. The risk of such side effects developing can be very variable and dependent on the skill and experience of the treating clinicians. Patients should enquire about the complication rates at the actual hospital they are considering being treated at.

Table 2

Treatment Selector Chart

Table 3

Side Effects Chart

Clinical results

Results from various studies of the success of brachytherapy are given in the tables below.

Table 4 Low-/intermediate-risk patients treated with brachytherapy monotherapy

SeriesYearNo of patientsFailure definitionFollow-up yearsPSA progression-free survival (%)
Khaksar et al32006300ASTRO593
Potters et al420051449ASTRO1281
Joseph et al5 2004667ASTRO875
Battermann et al62004351ASTROa1372
Beyer et al72003551ASTRO1098
Grimm et al82001125ASTRO modified1087

ASTROa: American Society for Therapeutic Radiology and Oncology. The ASTRO definition of biochemical PSA failure as a surrogate endpoint for recurrence is three rises of PSA before a failure is declared.9

Table 5 PSA progression-free survival for patients with intermediate-/high-risk prostate cancer treated with seed implant/external beam radiotherapy (EBRT) combined treatment

SeriesYearNo of patientsPSA failure definitionFollow-up yearsPSA progression-free survival intermediate/high (%)
Sylvester et al102007223ASTRO modified to 2 rises1580 / 67
Khashkar112006300ASTRO3.7575 / 80
Critz and Levinson1220041469 PSA <0.2ng/ml1080 / 61
Merrick et al13200446ASTRO784
Stock et al142004132ASTRO585 / 76

References

1:Ash D, Flynn A, Battermann J. ESTRO/EAU Urological Brachytherapy Group; EORTC Radiotherapy Group. ESTRO/EAU/EORTC recommendations on permanent seed implantation for localized prostate cancer. Radiother Oncol 2000;57:315 — 21.

2:Vernon M, Pais MD, Tamara Focht ME et al. Brachytherapy for Prostate cancer. Infect Urol 13(3):59 — 65, 2000.

3:Khaksar SJ, Laing RW, Henderson A et al. Biochemical (prostate-specific antigen) relapse-free survival and toxicity after 125I Low dose-rate prostate brachytherapy. BJU Int 2006;98:1210 — 15.

4:Potters L, Morgenstern C, Calugaru E et al. E12-year outcomes following permanent prostate brachytherapy in patients with clinically localized prostate cancer. J Urol 2005;173:1562 — 6.

5:Joseph J, Al-Qaisieh B, Ash D, Bottomley D, Carey B. Prostate-specific antigen relapse-free survival in patients with localized prostate cancer treated by brachytherapy. BJU Int 2004;94:1235 — 8.

6:Battermann JJ, Boon TA, Moerland MA. Results of permanent prostate brachytherapy, 13 years of experience at a single institution. Radiother Oncol 2004;71:23 — 8.

7:Beyer DC, Thomas T, Hilbe J, Swenson V. Relative influence of Gleason score and pretreatment PSA in predicting survival following brachytherapy for prostate cancer. Brachytherapy 2003;2:77 — 84.

8:Grimm PD, Blasko JC, Sylvester JE, Meier RM, Cavanagh W. 10-year biochemical (prostate-specific antigen) control of prostate cancer with (125)I brachytherapy. Int J Radiat Oncol Biol Phys 2001;51:31 — 40.

9:American Society for Therapeutic Radiology and Oncology Consensus Panel. Guidelines for PSA following radiation therapy. Int J Radiat Oncol Biol Phys 1997;37:1035 — 41.

10:Sylvester JE, Grimm PD, Blasko JC et al. 15-Year biochemical relapse free survival in clinical Stage T1 — T3 prostate cancer following combined external beam radiotherapy and brachytherapy; Seattle experience. Int J Radiat Oncol Biol Phys 2007;67:57 — 64.

11:Khaksar SJ, Langley SE, Lovell D, Laing RW. Interstitial low dose rate brachytherapy for prostate cancer - a focus on intermediate- and high-risk disease. Clin Oncol (R Coll Radiol). 2006 Sep;18(7):513-8.

12:Critz FA, Levinson K. 10-Year disease-free survival rates after simultaneous irradiation for prostate cancer with a focus on calculation methodology. J Urol 2004;172:2232 — 8.

13:Merrick GS, Butler WM, Wallner KE, Galbreath RW, Adamovich E. Permanent interstitial brachytherapy for clinically organ-confined high-grade prostate cancer with a pretreatment PSA < 20 ng/mL. Am J Clin Oncol 2004;27:611 — 15.

14:Stock RG, Cahlon O, Cesaretti JA, Kollmeier MA, Stone NN. Combined modality treatment in the management of high-risk prostate cancer. Int J Radiat Oncol Biol Phys 2004;59:1352 — 9.