Implications of bladder volume on target coverage and dose to critical structures during high dose rate intracavitary brachytherapy for cervical cancer: A dosimetric study

Background: The distension of the bladder during intracavitary brachytherapy (ICBT) affects the applicator position and in turn the dose to tumour and normal structures. Aims and Objectives: To quantify the changes in the dose to high risk clinical target volume (HRCTV) and organs at risk (OARs) due to bladder filling. Methods and Materials: In this prospective study, dosimetric parameters of 40 cervical cancer patients treated with (ICBT) were studied. Two sets of CT images with empty and bladder filled with 100 ml of contrast were used for analysis of doses to HRCTV and organs at risk OARs. The distance between posterior wall of the bladder and reference point on the flange was recorded in X,Y and Z. Results: Target coverage between bladder distension and empty bladder was 84.15 vs 84.85 % (P=0.003) respectively. Mean dose to bladder was 1.57vs 2Gy (P=0.000), median dose was 6 vs7.25Gy (P=0.000), D5cc was 3.94 vs 4.17 Gy (P=0.103) and D2cc was 4.5 vs 5 Gy (P=0.01) respectively. The doses to rectum was D2cc - 3.76 vs 4.07Gy (P=0.000), Sigmoid was D2cc - 2.18 vs 2.43Gy (P=0.005), bowel D2cc was 2.81 vs 3.43Gy (P=0.000). The mean distance of the posterior wall of the bladder from reference point was 0.042 vs -0.079cm (P=0.391) in the X-axis, -0.618 vs -0.630cm (P=0.603) in Z-axis and 0.19 vs 0.26cm (P=0.009) in the Y-axis between two status of the bladder. Conclusions: Smaller volume of bladder receive higher dose and larger volumes a lower dose with bladder distension, while dose is same for rectum, sigmoid and bowel. The applicators shift posteriorly when the bladder is distended

Obstrução do Trato Urinário Baixo Fetal / Fetal lower urinary tract obstruction

A obstrução do trato urinário baixo fetal (fetal lower urinary tract obstruction - LUTO) é uma patologia caracterizada por dilatação da bexiga e hidronefrose bilateral causada por obstrução do trato urinário inferior. Sua incidência é de 2,2 em cada 10.000 nascimentos. A etiologia da LUTO inclui a válvula da uretra posterior (VUP), atresia ou estenose uretral. O diagnóstico é feito por ultrassom, que mostra bexiga dilatada, com paredes espessas (megabexiga), e uretra posterior aumentada. O tratamento cirúrgico clássico (derivação vésico-amniótica guiada por ultrassom) estaria indicado quando o líquido amniótico normal começa a diminuir, com aumento da distensão vesical e da hidronefrose. O tratamento inclui a colocação de derivação vésico-amniótica guiado pelo ultrassom e fetoscópica com coagulação a laser. De acordo com a gravidade, a LUTO é classificada nos estágios 1,2 e 3.(AU)

The Fetal Lower Urinary Tract Obstruction (LUTO) is a spectrum of diseases characterized by bladder distension and bilateral hydronephrosis in consequence of the LUTO. The incidence is approximately 2.2 in 10,000 births and it is commonly diagnosed during the late first or early second trimester of pregnancy. The etiologies of LUTO include posterior urethral valves, urethral atresia and urethral stenosis. Complete bladder outlet obstruction (severe LUTO) is associated with high perinatal mortality due to pulmonary hypoplasia and severe renal impairment/damage. The prenatal intervention includes vesicoamniotic shunt placement guided by ultrasound and fetoscopic laser coagulation. It is suggested that LUTO patients could be categorized in three stages according to disease gravity: Stages 1, 2 and 3.(AU)

Extraperitoneal Bladder Rupture during the Bladder Distension Therapy: A case report

A 75-year-old woman presented a cauda equina syndrome with epiconus involvement from the compression fractures of T12, L1, and L3 vertebrae as a result of fall accident. Cystometrogram performed at three months after the injury showed a small bladder capacity and low compliance. Anticholinergic medications including intravesical instillation of oxybutynin solution failed to increase the bladder capacity or lower the intravesical pressure. Bladder distension therapy using normal saline infusion with a volume surpassing the previous measured maximal bladder capacity was performed. The procedures were repeated four times per day. At the fifth day of the distension therapy, the patient complained of acute low abdominal pain and gross hematuria. The cystogram revealed the extraperitoneal bladder rupture. The patient was treated successfully with antibiotics and continuous urinary drainage through the Foley catheter for 14 days. We report a case of extraperitoneal bladder rupture during the bladder distension therapy.