Single-Center Experience in Prostate Fiducial Marker Placement: Technique and Midterm Follow-up

Transperineal versus transrectal prostate fiducial insertion in radiation treatment of prostate cancer: a systematic review and meta-analysis

PURPOSE

To provide more accurate and definitive conclusions regarding the clinical and technical complications associated with the transperineal (TP) and transrectal (TR) approaches, a comprehensive review of observational studies and randomized controlled trials was conducted. This systematic review covered all eligible studies to facilitate a thorough comparison of complications linked to the two fiducial marker insertion methods, TP and TR.

METHODS

A comprehensive search of the literature was conducted, encompassing databases such as PubMed, Embase, and the Cochrane Library, up to July 7, 2023. The relative risk and 95% confidence interval were utilized to evaluate the diagnosis and complication rates.

RESULTS

The final selection for the methodological quality analysis included 13 observational studies that utilized TP and TR gold fiducial insertion approaches. The meta-analysis revealed significantly lower risks of urinary tract infections (UTI) and rectal bleeding with the TP approach.

CONCLUSION

The use of both TP and TR techniques for placing gold seed fiducial markers has proven to be an effective, safe, and well-tolerated method for image-guided radiation therapy in prostate cancer patients. A significant benefit of the TP technique is its ability to avoid rectal puncture, thereby reducing the risk of UTIs. Although the incidence of UTIs and rectal bleeding associated with the TR method is relatively low, these complications can disrupt patient wellbeing and potentially cause delays in treatment.

CT-guided Transgluteal Prostate Fiducial Marker Insertion for Localized Radiation Therapy

PURPOSE

To Evaluate the safety and technical success of transgluteal CT-guided fiducial marker implantation into the prostate as an alternative method to transperineal and transrectal approaches.

MATERIAL AND METHODS

We retrospectively identified all patients who had undergone CT-guided transgluteal fiducial marker insertion between 2020 and 2022. Four patients with confirmed prostate cancer were identified. One radiologist performed all procedures via a bilateral transgluteal approach under the guidance of real-time CT-fluoroscopy. Twenty cm long pre-waxed 18G guiding needles, preloaded with smooth gold fiducial markers, were used to implant markers. Technical success was defined as the successful placement of the fiducial markers into the planned positions.

RESULTS

The mean age of patients was 70 years. The mean procedure time was 19.25 (SD: 6.75) min, and the mean total dose length product (DLP) was 801.75 (SD: 291.17) mGycm, which is compatible with the 12 mSv estimated effective dose. All procedures were technically successful (100%). All patients tolerated the procedure and did not require any analgesia for pain, and there were no requests to stop or pause the procedure. Only one patient reported hematuria one day after the procedure, which required no treatment.

CONCLUSION

Transgluteal CT-guided fiducial marker implantation into the prostate is an alternative method to transperineal and transrectal approaches. In this technique, the risk of septic complications is minor, and general anesthesia is not required. Thus, transgluteal CT-guided marker insertion is a feasible and well-tolerated method for image-guided radiation therapy (IGRT) in patients with prostate cancer.

Intra-prostatic gold fiducial marker insertion for image-guided radiotherapy (IGRT): five-year experience on 795 patients

INTRODUCTION

Prostate cancer is the second most commonly diagnosed cancer in males. The use of intra-prostatic fiducial markers (FM) for image-guided radiotherapy (IGRT) has become widespread due to their accuracy, relatively safe use, low cost, and reproducibility. FM provides a tool to monitor prostate position and volume changes. Many studies reported low to moderate rates of complications following FM implantation. In the current study, we present our five years' experience regarding the insertion technique, technical success, and rates of complication and migration of intraprostatic insertion of FM gold marker.

METHODS

From January 2018 to January 2023, 795 patients with prostate cancer candidate for IGRT (with or without a history of radical prostatectomy) enrolled in this study. We used three fiducial markers (3*0.6 mm) inserted through an 18-gauge Chiba needle under transrectal ultrasonography (TRUS) guidance. The patients were observed for complications up to seven days after the procedure. Besides, the rate of marker migration was recorded.

RESULTS

All procedures were completed successfully, and all patients tolerated the procedure well with minimal discomfort. The rate of sepsis after the procedure was 1%, and transient urinary obstruction was 1.6%. Only two patients experienced marker migration shortly after insertion, and no fiducial migration was reported throughout radiotherapy. No other major complication was recorded.

DISCUSSION

TRUS-guided intraprostatic FM implantation is technically feasible, safe, and well-tolerated in most patients. The FM migration can seldom occur, with negligible effects. This study can provide convincing evidence that TRUS-guided intra-prostatic FM insertion is an appropriate choice for IGRT.

Infection after prostatic transrectal fiducial marker implantation for image guided radiation therapy

PURPOSE

The aim of this retrospective study is to assess the risk of infection after transrectal ultrasound-guided fiducial marker insertion for image-guided radiotherapy of prostate cancer.

MATERIAL AND METHODS

Between January 2016 and December 2020, 829 patients scheduled for intensity-modulated radiotherapy for prostate cancer had an intraprostatic fiducial marker transrectal implantation under ultrasound guidance by radiation-oncologists specialized in brachytherapy. Patients received standard oral prophylactic antibiotic with quinolone. If Gram negative bacteria resistant to quinolone were detected at the time of the prostate cancer biopsies, the antibioprophylaxis regimen was modified accordingly. The resistance to quinolone screening test was not repeated before fiducial marker insertion. Infectious complications were assessed with questionnaires at the time of CT-planning and medical record reviewed. Toxicity was evaluated according to CTCAE v5.0.

RESULTS

The median time between fiducial marker implantation and evaluation was 10 days (range: 0-165 days). Four patients (0.48%) developed urinary tract infection related to the procedure, mostly with Gram-negative bacteria resistant to quinolone (75%). Three had a grade 2 infection, and one patient experienced a grade 3 urosepsis. The quinolone-resistance status was known for two patients (one positive and one negative) and was unknown for the other two patients prior to fiducial marker implantation.

CONCLUSION

Intraprostatic transrectal fiducial marker implantation for image-guided radiotherapy is well tolerated with a low rate of infection. With such a low rate of infection, there is no need to repeat the search of Gram-negative bacteria resistant to quinolone before fiducial marker implantation if it was done at the time of prostate biopsies. Optimal antibioprophylaxis should be adapted to the known status of Gram-negative bacteria resistant to quinolone.

Feasibility of transrectal and transperineal fiducial marker placement for prostate cancer before proton therapy

BACKGROUND

To compare the feasibility of transrectal and transperineal fiducial marker placement for prostate cancer before proton therapy.

MATERIALS AND METHODS

From 2013 to 2015, the first 40 prostate cancer patients that were scheduled for proton therapy underwent transrectal fiducial marker placement, and the next 40 patients underwent transperineal fiducial marker placement (the first series). Technical and clinical success and pain scores were evaluated. In the second series (n = 280), the transrectal or transperineal approach was selected depending on the presence/absence of comorbidities, such as blood coagulation abnormalities. Seven patients refused to undergo the procedure. Thus, the total number of patients across both series was 353 (262 and 91 underwent the transrectal and transperineal approach, respectively). Technical and clinical success, complications, marker migration and the distance between the two markers were evaluated.

RESULTS

In the first series, the technical and clinical success rates were 100% in both groups. The transrectal group exhibited lower pain scores than the transperineal group. The overall technical success rates of the transrectal and transperineal groups were 100% (262/262) and 99% (90/91), respectively (P > 0.05). The overall clinical success rate was 100% in both groups, and there were no major complications in either group. The migration rates of the two groups did not differ significantly. The mean distance between the two markers was 25.6 ± 7.1 mm (mean ± standard deviation) in the transrectal group and 31.9 ± 5.2 mm in the transperineal group (P < 0.05).

CONCLUSION

Both the transrectal and transperineal fiducial marker placement methods are feasible and safe.

Cost-Effectiveness of the Use of Gold Anchor™ Markers in Prostate Cancer

Introduction

A common treatment for prostate cancer is external beam radiation therapy. A way to target the radiation is to use implantable gold fiducial markers (GFMs). The GFMs serve as reference points enabling tumor localization during treatment. Today, there are several GFMs available on the market but no clinical guidelines as to which one to use. The aim of this study was to estimate the cost-effectiveness of Gold Anchor GFMs (Naslund Medical AB, Huddinge, Sweden) implanted with a 22G needle, compared to other GFMs implanted with a 17-18G needle, in the prostate gland of patients with prostate cancer.

Methods

Costs, life years, and quality-adjusted life years (QALYs) were estimated over a lifelong time horizon for each treatment strategy using a decision-analytic model. Data used in the model were obtained from published literature or were estimated by an expert elicitation technique. The primary outcome measure was an incremental cost-effectiveness ratio (ICER).

Results

Gold Anchor GFM was found to be a dominant alternative with both lower costs [-8.7 US Dollars (USD)] and a gain in QALYs (0.015) when compared with other GFMs. The lower cost was achieved by fewer visits for imaging in treatment planning, and by reduced risk of infections and sepsis. The QALY gain was driven by a reduced risk of sepsis.

Conclusion

The use of Gold Anchor GFMs as reference points to target radiation is a cost-effective alternative when compared to other GFMs. However, this analysis is based on expert elicitation regarding some crucial parameters, and further clinical studies of the use of GFMs are needed.

Prostate Fiducial Marker Placement in Patients on Anticoagulation: Feasibility Prior to Prostate SBRT

Background and Purpose: Fiducial marker placement is required in patients undergoing robotic-based Stereotactic Body Radiotherapy (SBRT) or image-guided radiation therapy (IGRT) for prostate cancer. Many patients take antiplatelet or anticoagulant medication due to other medical comorbidities. They are often required to temporarily discontinue these medications prior to invasive medical procedures as they are prone to bleed. Some patients are unable to discontinue therapy due to an elevated risk of thromboembolic events. The purpose of this study is to report this institution's experience placing fiducial markers in prostate cancer patients who are on chronic antiplatelet or anticoagulant medication. Materials and Methods: From August 2015-March 2019 57 patients on chronic antiplatelet or anticoagulation therapy who were not cleared to stop these medications underwent transrectal ultrasound guided (TRUS) fiducial marker placement for SBRT/IGRT. All patients were monitored by a registered nurse during the procedure for prolonged bleeding that required staff to hold pressure to the area with a 4 × 4 gauze until it resolved. All patients were also called the following day to assess for ongoing bleeding events. Treatment planning CT scan confirmed the ideal geometry of the marker placement. Results: All 57 patients on antiplatelet or anticoagulant medication who underwent fiducial marker placement were discharged home the same day of the procedure. Four patients experienced persistent bleeding that required a nurse to hold prolonged pressure to the area. No patient experienced significant bleeding the following day or any untoward cardiovascular event. Conclusions: This series suggests the use of antiplatelet or anticoagulant medication is not an absolute contraindication to fiducial marker placement in patients undergoing SBRT or IGRT for prostate cancer. These patients should be closely monitored after the procedure for bleeding complications. Practitioners may consider the patient's medical comorbidities, risk factors for thromboembolism, and overall functional status as there is no standardized protocol for discontinuing anticoagulant or antiplatelet therapy for fiducial marker placement.

Low Infection Rate After Transrectal Implantation of Gold Anchor ™ Fiducial Markers in Prostate Cancer Patients After Non-broad-spectrum Antibiotic Prophylaxis

Background In 621 consecutive prostate cancer patients, the frequency of urinary tract infections (UTI) and marker loss was evaluated. They prophylactically received a single dose of non-broad-spectrum antibiotics and transrectal implantation of three thin needle fiducial markers, Gold Anchor ™ (GA). Methods The occurrence of UTIs, sepsis, hospitalization due to infection, and marker loss after implantation was assessed from the medical records containing notes from physicians and nurses from the day of implantation to the end of 29 fractions. Results UTIs occurred in two (0.3%) of the 621 patients. Neither sepsis nor hospitalization was noted. Loss/drop-out of three markers was noted among 1,863 markers implanted. Conclusion The use of thin needles for the implantation of fiducials appears to reduce the rate of infection despite the use of a single dose of non-broad-spectrum antibiotics as prophylaxis. The marker construct appears to provide stability in the tissues.

Fiducial marker guided prostate radiotherapy: a review

Image-guided radiotherapy (IGRT) is an essential tool in the accurate delivery of modern radiotherapy techniques. Prostate radiotherapy positioned using skin marks or bony anatomy may be adequate for delivering a relatively homogeneous whole-pelvic radiotherapy dose, but these surrogates are not reliable when using reduced margins, dose escalation or hypofractionated stereotactic radiotherapy. Fiducial markers (FMs) for prostate IGRT have been in use since the 1990s. They require surgical implantation and provide a surrogate for the position of the prostate gland. A variety of FMs are available and they can be used in a number of ways. This review aimed to establish the evidence for using prostate FMs in terms of feasibility, implantation procedures, types of FMs used, FM migration, imaging modalities used and the clinical impact of FMs. A search strategy was defined and a literature search was carried out in Medline. Inclusion and exclusion criteria were applied, which resulted in 50 articles being included in this review. The evidence demonstrates that FMs provide a more accurate surrogate for the position of the prostate than either external skin marks or bony anatomy. A combination of FM alignment and soft-tissue analysis is currently the most effective and widely available approach to ensuring accuracy in prostate IGRT. FM implantation is safe and well tolerated. FM migration is possible but minimal. Standardization of all techniques and procedures in relation to the use of prostate FMs is required. Finally, a clinical trial investigating a non-surgical alternative to prostate FMs is introduced.

Extreme hypofractionation for early prostate cancer: Biology meets technology

The aim of this review is to present the available radiobiological, technical and clinical data about extreme hypofractionation in primary prostate cancer radiotherapy. The interest in this technique is based on the favourable radiobiological characteristics of prostate cancer and supported by advantageous logistic aspects deriving from short overall treatment time. The clinical validity of short-term treatment schedule is proven by a body of non-randomised studies, using both isocentric (LINAC-based) or non-isocentric (CyberKnife^®-based) stereotactic body irradiation techniques. Twenty clinical studies, each enrolling more than 40 patients for a total of 1874 treated patients, were revised in terms of technological setting, toxicity, outcome and quality of life assessment. The implemented strategies for the tracking of the prostate and the sparing of the rectal wall have been investigated with particular attention. The urinary toxicity after prostate stereotactic body irradiation seems slightly more pronounced as compared to rectal adverse events, and this is more evident for late occurring events, but no worse as respect to conventional fractionation schemes. As far as the rate of severe acute toxicity is concerned, in all the available studies the treatment was globally well tolerated. While awaiting long-term data on efficacy and toxicity, the analysed studies suggest that the outcome profile of this approach, alongside the patient convenience and reduced costs, is promising. Forty-eight ongoing clinical trials are also presented as a preview of the expectation from the near future.

Bacterial Urinary Tract Infection after Transrectal Placement of Fiducial Markers prior to Proton Radiotherapy for Prostate Cancer

PURPOSE

To determine the incidence of a bacterial urinary tract infection (UTI) necessitating hospitalization after transrectal placement of fiducial markers prior to proton radiotherapy (RT) for prostate cancer.

MATERIALS AND METHODS

Six hundred sixty six patients returning for follow up after proton RT consented to participate in this institutional review board (IRB) approved study. Patients were queried whether they required hospitalization within 1 month of transrectal placement of fiducial markers. Patients were treated with proton RT between August 2006 and December 2014. Median International Prostate Symptom Score (IPSS) was 7. Sixty four patients (9.6%) had diabetes, 9 patients (1.4%) had chronic obstructive pulmonary disease, 6 patients (0.9%) had prior bladder surgery, 7 patients (1.1%) had a transurethral prostatectomy within 3 months, and 549 patients (82.4%) had a course of antibiotics within 6 months. Fifty five patients (8.3%) were taking tamsulosin, 16 patients (2.4%) were taking finasteride, and 62 patients (9.3%) were taking saw palmetto. The interval between the most recent prostate biopsy prior to fiducial placement and fiducial marker placement was less than 6 months in 609 patients (91.4%). No patient had a prior recent rectal culture.

RESULTS

Ten patients (1.5%) developed a bacterial UTI necessitating hospitalization after transrectal placement of fiducial markers. A bacterial UTI occurred in 3 (0.7%) of 440 patients treated from 2006 to 2012 and in 7 (3.1%) of 226 patients treated from 2013 to 2014. Univariate analysis of potential association of a bacterial UTI with the following parameters revealed: IPSS less than or greater than the median (p=0.3400), diabetes (p=0.6099), tamsulosin (p=0.9999), saw palmetto (p=0.0093), interval between prostate biopsy and placement of fiducials (p=0.9999), year of treatment (p=0.0363), and antibiotics within 6 months (p=0.2233). A bacterial UTI was observed in 4 (6.5%) of 62 patients who were taking saw palmetto versus 6 (1.0%) of 604 patients who were not taking this medication. The incidence of a bacterial UTI between 2006 and 2012 was 3 (0.7%) of 440 patients and from 2013 to 2014 was 7 (3.1%) of 226 patients. Multivariate analysis revealed that the likelihood of a bacterial UTI was increased in patients taking saw palmetto (p=0.0044) and those treated in 2013-2014 (p=0.0303).

CONCLUSION

The incidence of a bacterial UTI requiring hospitalization after transrectal placement of fiducial markers prior to proton RT was 1.5% and was impacted by taking saw palmetto and year of treatment. Patients treated during 2013 and 2014 had a significantly higher risk of a bacterial UTI requiring hospitalization.