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.

Clinical applications of high dose rate endorectal brachytherapy for patients with rectal cancer.

With the establishment of total mesorectal excision for the treatment of rectal cancer, local recurrence rates have significantly decreased. The addition of preoperative external beam irradiation further reduces this risk to less than 6%. As the local treatment becomes successful and more widely used, the associated treatment-related toxicity is becoming clinically important. If 4 to 6% of the patients are to benefit from neo-adjuvant therapy before total mesorectal excision, the acute and the long-term toxicity burden must be reasonable. With the introduction of better-quality imaging for tumour visualization and treatment planning, a new-targeted radiation treatment was introduced with high dose rate endorectal brachytherapy. The treatment concept was tested in phase I and II studies first in the preoperative setting, then as a boost after external beam radiation therapy as a dose escalation study to achieve higher tumour local control in a radical treatment setting with no surgery. High dose rate endorectal brachytherapy is safe and effective in achieving high tumour regression rate and was well tolerated. It is presently explored in a phase III dose escalation study in the non-operative management of patients with operable rectal cancer.

Stereotactic Ablative Radiotherapy Versus Low Dose Rate Brachytherapy or External Beam Radiotherapy: Propensity Score Matched Analyses of Canadian Data.

AIMS: To compare biochemical failure-free survival (BFFS) and overall survival for prostate cancer treated with stereotactic ablative radiotherapy (SABR), low dose rate (LDR) brachytherapy or external beam radiotherapy (EBRT) using a large Canadian multi-institutional database. MATERIALS AND METHODS: Patients with low risk localised prostate cancer treated with SABR, LDR or EBRT and no androgen deprivation therapy were selected. Propensity score matching was used to create two sets of matched cohorts with LDR and EBRT serving as control groups. Kaplan-Meier survival analysis and Cox proportional hazards regression were used to compare differences in BFFS and overall survival between treatment groups. RESULTS: The pre-matched cohort contained 602 patients; the median follow-up was >5.0 years. There were no significant differences in BFFS before or after matching for SABR versus LDR but the prostate-specific antigen (PSA) nadir was lower after LDR. For the SABR versus EBRT, SABR had a BFFS trend before matching (P = 0.08), which became significant after matching (P < 0.001). CONCLUSIONS: Using the Genitourinary Radiation Oncologists of Canada Prostate Cancer Risk Stratification database, low risk prostate cancer patients receiving SABR had similar BFFS compared with patients receiving LDR but better BFFS than EBRT patients. Further comparative studies of efficacy, quality of life and economic outcomes using a broader risk of patients are warranted.

RTOG 0518: randomized phase III trial to evaluate zoledronic acid for prevention of osteoporosis and associated fractures in prostate cancer patients.

BACKGROUND: RTOG 0518 evaluated the potential benefit of zoledronic acid therapy in preventing bone fractures for patients with high grade and/or locally advanced, non-metastatic prostate adenocarcinoma receiving luteinizing hormone-releasing hormone (LHRH) agonist and radiotherapy (RT). METHODS: Eligible patients with T-scores of the hip (<-1.0, but >-2.5 vs >-1.0) and negative bone scans were prospectively randomized to either zoledronic acid, 4 mg, concurrently with the start of RT and then every six months for a total of 6 infusions (Arm 1) or observation (Arm 2). Vitamin D and calcium supplements were given to all patients. Secondary objectives included quality of life (QOL) and bone mineral density (BMD) changes over a period of three years. RESULTS: Of 109 patients accrued before early closure, 96 were eligible. Median follow-up was 36.3 months for Arm 1 and 34.8 months for Arm 2. Only two patients experienced a bone fracture (one in each arm) resulting in no difference in freedom from any bone fracture (P=0.95), nor in QOL. BMD percent changes from baseline to 36 months were statistically improved with the use of zoledronic acid compared to observation for the lumbar spine (6% vs -5%, P<0.0001), left total hip (1% vs -8%, P=0.0002), and left femoral neck (3% vs -8%, P=0.0007). CONCLUSIONS: For patients with advanced, non-metastatic prostate cancer receiving LHRH agonist and RT, the use of zoledronic acid was associated with statistically improved BMD percent changes. The small number of accrued patients resulted in decreased statistical power to detect any differences in the incidence of bone fractures or QOL.

[The impact of 3D image guided prostate brachytherapy on therapeutic ratio: the Quebec University Hospital experience]. / Le rôle de la curiethérapie prostatique guidée par imagerie 3D sur le ratio thérapeutique: l'expérience du CHU de Québec.

PURPOSE: To evaluate the impact of adaptative image-guided brachytherapy on therapeutic outcome and toxicity in prostate cancer. MATERIALS AND METHODS: The 1,110 first patients treated at the CHUQ-l'Hôtel-Dieu de Québec were divided in five groups depending on the technique used for the implantation, the latest being intra operative treatment planning. Biochemical disease free survival (5-bDFS), toxicities and dosimetric parameters were compared between the groups. RESULTS: 5-bDFS (ASTRO+Houston) were of 88.5% and 90.5% for the whole cohort. The use of intra operative treatment planning resulted in better dosimetric parameters. Clinically, this resulted in a decreased use of urethral catheterism, from 18.8% in group 1 to 5.2% in group 5, and in a reduction in severe acute urinary side effects (21.3 vs 33.3% P=0.01) when compared with preplanning. There was also less late gastrointestinal side effects (groups 5 vs 1: 26.6 vs 43.2% P<0.05). Finally, when compared with preplanning, intra operative treatment planning was associated with a smaller reduction between planned D90 and the dose calculated at the CT scan 1 month after the implant (38 vs 66 Gy). CONCLUSION: The evolution of prostate brachytherapy technique toward intra operative treatment planning allowed dosimetric gains which resulted in significant clinical benefits by increasing the therapeutic ratio mainly through a decreased urinary toxicity. A longer follow-up will answer the question whether there is an impact on 5-bDFS.

Autonomic function testing in children and adolescents with diabetes mellitus.

Cardiac autonomic neuropathy (CAN) is a common complication in type 1 diabetes mellitus (T1DM) and associated with an increased mortality. Early detection of CAN would be desirable for a better individual risk stratification. The aim of this study was to determine whether autonomic dysfunction can be diagnosed in young patients with a recent history of T1DM. Autonomic function was assessed in 20 pediatric patients with T1DM, aged 10-19 yr, and a control group of 136 non-diabetic patients using four cardiorespiratory reflexes: heart rate and blood pressure response in standing position, deep breathing, and Valsalva maneuver. Furthermore, power spectral analyses of the low- and high-frequency band of heart rate variability (HRV) and baroreflex sensitivity (BRS) were tested with the non-invasive Task force monitor (CNSystems, Graz, Austria). Cardiorespiratory reflexes were pathologic for at least one item in 75% of the diabetic and 60% in the healthy control group. A reduced BRS was always combined with abnormal HRV. We found this pattern in 30% of diabetic patients and never in the control group. In patients with impaired BRS, mean hemoglobin A1c (HbA1c) was 7.7% and duration of diabetes 6.5 yr. This did not differ from the overall value of the diabetic group: HbA1c level 8.4% and diabetes duration 7.3 yr. In conclusion, signs of autonomic dysfunction are not uncommon in an early stage of diabetes in young patients. Classical cardiorespiratory reflexes seem to be less specific than HRV and BRS as testing methods.