Needle Displacement during High-Dose-Rate Afterloading Brachytherapy Boost and Conventional External Beam Radiation Therapy for Initial and Local Advanced Prostate Cancer

Abstract

Purpose: To determine the displacement of needles (ND) and its impact in the outcome of initial and locally advanced prostate cancer treated with conventional external beam radiation therapy (EBRT) and fractionated transrectal ultrasound-guided high-dose-rate afterloading brachytherapy (HDR-BT) as a boost. Methods and Materials: From 03/97 to 08/98 a total of 47 patients were eligible for study entry. Patients with 1992 AJCC clinical stage T3a or less and prostatic volume ≤60 cm³ were eligible. Prior to HDR-BT, all patients had a course of pelvic localized EBRT up to a median dose of 46 Gy (range 45–50.4). Results: Median age was 68 years (range 47–83) and median follow-up 48 months (range 36–53). Minimal or no needle displacement occurred in 17% (8/47) of patients. There were 61.7% (29/47) of patients who needed one correction and 21.3% (10/47) who needed two corrections. There were no correlations with ND (p = 0.130) and times of ND (p = 0.295) occurrence with bNED. The crude and actuarial biochemical controls (bNED) in 53 months for all patients were 87.2 and 82.3% respectively. Actuarial bNED after 4 years in patients without and with ND were 75 and 89.7% (p = 0.254). Discussion: There are many advantages when HDR-BT is used, but the most important ones are the capability of on-line dosimetry and quality control. The procedure is very conformal, with dose-volume histograms representing the administered dose, but we still need to wait for results of phase III open trials that analyze HDR-BT and conformal therapy.

A Small Tolerance for Catheter Displacement in High–Dose Rate Prostate Brachytherapy is Necessary and Feasible

“…It was unclear from the study of Hoskin et al (5) whether a margin around the CTV was added to give a treatment volume, whereas Pellizon et al (13) specified that the minimum dose was to be 4 to 6 mm outside the peripheral catheters. Although the margin for acceptable catheter displacement will depend to some extent on the shape of the prostate, catheter arrangements, and dose distribution during planning, our data suggest that this margin should be smaller and that it is feasible to obtain displacements of less than 3 mm.…”

Effect of pFNA internal fixation of senile fracture in maxillofacial injuries

“…Descriptions of both the TRUS based and CT based procedures are given below, and the steps of a TRUS based HDR implant procedure are detailed in Ref. [89] following adequate anaesthesia and positioning of the patient in the lithotomy position, a Foley catheter is introduced. The catheter can be filled with aerated gel for improved visibility on TRUS images.…”

Influence of catheters on predicted tumour control probability and severity of acute genitourinary toxicity during high-dose-rate brachytherapy prostate boost

“…5 High-dose-rate brachytherapy (HDR) is an alternative method to deliver higher dose to the target as with needles in place only insignificant movements occur during treatment. 12 Our study aimed to evaluate the impact of catheters position, their number and repeated catheter manipulations on the optimal dose to the prostate and urethra, tumour control probability (TCP) and on the severity of acute GU toxicity; subsequently these results were used to find the solutions for adequate position, number of the catheters and various dosimetric parameters. 6 However, similar to setup errors in external beam radiotherapy (EBRT), various factors may cause the dose uncertainties in HDR brachytherapy, including needle induced trauma and subsequent change in target volume, 7 edema resolution between fractions, 8 visualization of urethra 9 and computed tomography (CT) slice thickness.…”

“…After the implantation, individual needles do not move relative to one another or to perineal templates used, but there is a tendency for them to displace inferiorly relative to the prostate as a single unit, 11 this can lead to under dosage of prostate. Various methods have been proposed to compensate this movement 12 …”

“…Various methods have been proposed to compensate this movement. 12 Our study aimed to evaluate the impact of catheters position, their number and repeated catheter manipulations on the optimal dose to the prostate and urethra, tumour control probability (TCP) and on the severity of acute GU toxicity; subsequently these results were used to find the solutions for adequate position, number of the catheters and various dosimetric parameters.…”