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  • br The procedure typically takes

    2019-11-11


    The procedure typically takes approximately 75 min, and after general anesthesia recovery, patients are imaged with CT MRI scans for treatment planning. First treat-ment fraction is delivered on the day of the procedure, fol-lowed by one or two fractions in the second day. On average, patients are in hospital with the applicator in situ for 32 h.
    After applicator insertion, patients are admitted into the inpatient ward with a urinary catheter in place. Perineal bleeding and hematuria are recorded by the nursing staff. Either oral or intravenous (via pain pump) opioids are given for pain control. Low molecular weight heparin is used for deep vein thrombosis prophylaxis. Patients also receive a low-residue diet and standing loperamide for peristalsis reduction. A minimum time of 6 h is respected between each HDR brachytherapy fractions. After last BT fraction, the applicator is removed and patients are discharged as long as there is no active bleeding present and patient is able to void. Patients receiving a subsequent applicator implant are readmitted the following week and similar clin-ical care is provided.
    Planning and treatment
    After the procedure, target and CY7-SE at risk are con-toured at a MIM Vista (MIM Software Inc., Cleveland, OH) planning station using CT MRI scans. Planning oc-curs at Oncentra Brachy (Nucletron, Veenendaal, the Netherlands) after importing images and contours from MIM Vista. In Oncentra Brachy, catheters are manually re-constructed in the CT scan and a plan is created by inverse optimization with Inverse Planning Simulated Annealing algorithm. Needles found to be inside an organ at risk have their intruded section manually unloaded during planning. No attempt is made to readjust needle positioning and depth after CT imaging. Plans are evaluated and approved based on ABS and GEC-ESTRO guidelines (10,11).
    Data record and complications
    Acute complications were measured prospectively under a prospective registry trial. In this study, complications were analyzed from the day of the procedure until hospital discharge, at first followup appointment, 6 weeks after ISBT, and in any interim visits up to and including 3 months. Complications were scored by CTCAE (V4.03) score system.
    Radiological analysis
    The CT and MRI scans used during treatment planning were used for quantification of visceral intrusion. As part
    of the institutional protocol, at least one scan was requested for every two BT fractions. Patients with cervical cancer commonly had one CT scan for each brachytherapy fraction.
    All scans used for planning were retrospectively evaluated by two physicians (LCM and PL). Intrusions to organs at risk (bladder, rectum, and bowel) were independently quantified by both authors through evaluation of the axial, sagittal, and coronal planes. Visceral intrusion was only considered when the needle tip or shaft was seen simultaneously inside an or-gan in all image planes (axial, sagittal, and coronal). When disagreement was found between observers, an experienced body radiologist reviewed the scans.
    Statistical analysis
    Descriptive analysis was used to describe organ intrusion and complications. Variables were analyzed with appropriate measures of central tendency and dispersion. Fisher exact test assessed intrusions and complication events. Wilcoxon rank sum test evaluated the correlation between number of in-serted needles and complication events. A p-value !0.05 was considered statistically significant.
    Results
    From the 48 patients, 46 were discharged on the day of template removal. One patient was kept an extra day due to asymptomatic hyperkalemia and the other due to vomiting. All patients were followed by at least 3 months after brachytherapy. Indications for ISBT were as follows: locally advanced cervical cancers (n 5 16), cervical can-cers with postsurgery local recurrences (n 5 2), vaginal pri-mary cancers (n 5 12), pelvic recurrent uterine cancers (n 5 13), and others (n 5 5). Six patients received ISBT only because of previous course of pelvic EBRT or in the palliative setting. Forty-two patients received EBRT to the pelvis with a median dose of 45 Gy (range 42.5e 50.4 Gy).