Introduction

The development of abnormal tissue in the bladder lining tissue, and in some cases, the tumours growing into the bladder muscle, is known as urinary bladder cancer (UBC). Tumors may develop when more cancer cells proliferate. Over time, these tumors may spread to other parts of the body, which called metastasis. ⁽¹⁾

As estimated by Global Cancer Observatory (GLOBOCAN) in December 2020, UBC is the third most prevalent cancer in Egypt with (26,986) patients with a mortality of (6170) patients in 2020, also bladder cancer remains the second most common cancer among Egyptian males.⁽²⁾ Urinary obstruction, frequent urination, urgency, gross hematuria, and recurrent UTIs are the most common symptoms of UBC. ⁽³⁾

The International Agency for Research on Cancer (IARC) has reported sufficient evidence for UBC risk factors that may be mainly because of tobacco smoking. ⁽⁴⁾Although a small tumour that is located within the bladder might remain undetected by conventional techniques, early detection of bladder cancer can improve treatment outcomes. ⁽⁵⁾

The gold standard techique to detect UBC is a cystoscopy, which can be performed while the patient is either under local or general anesthesia. Some of the disadvantages of cystoscopy include the possibility of to miss a small flat tumor, hematuria, UTI, and urethral damage from the equipment used during the procedure. ⁽⁶⁾

Computed tomography urography (CTU) is a widely used procedure that takes at least one series of images during a CT scan of the bladder, ureters, and kidneys. Any CTU protocol starts with the plain phase, also known as the unenhanced phase (UP), and continues with imaging in the nephrogenic phase (NP) and excretory phase (EP), after intravenous administration of a contrast agent. ⁽⁷⁾

Standard CTU may miss small UBC because it is might difficult to observe especially in excretory phase (EP) due to the fluid level and contrast agent may mixed with urine in this phase so bladder lesions may be missed or detected as filling defect. This may leads to decrease the detection sensitivity and accuracy of UBC. ⁽⁸⁾

To increase the sensitivity of detecting of UBC a new technique called Multiphasic CTU that consists of four phases which are an unenhanced phase (UN), a corticomedullary phase (CMP) also known as an arterial phase, a nephrographic phase (NP), and a excretory phase (EP). In addition, to increase the sensitivity and accuracy of the excretory phase bladder expansion is needed so that patients were given about 500 mL of fresh water prior to the CT scan So that avoiding missing flat tumors by blooming effect. Multiphasic CTU may be similar sensitive in detecting UBC as cystoscopy and more sensitive that three phases CTU. ⁽⁹⁾

Patients & Methods

This is a prospective cohort study conducted on 25 suspected urinary bladder cancer patients were referred from department of radiology at Minia Oncology Center from December 2022 to October 2023 and after ethical approval by department committee. Written and informed consent was obtained from all patients with risk explanation prior to the CT scanning.

1-     Inclusion criteria:

• Patients with gross
• Patients suspected with bladder cancer by
• Patients with positive urine
• Age older than 18
• Both

2-     Exclusion criteria:

• Pregnant
• Patient with history of contrast
• Patient with renal
• Patient less than 18 years’

Methods:

All patients were subjected to the followings:

1-     Complete full history taking including:

• All patients will give written consent before inclusion in the study.
• Family history and daily
• History of previous surgeries or previous
• History of any CT contraindications.
• Patients will have required laboratory test (Renal function) before using contrast

2-       Laboratory examination:

• Complete blood picture (CBC):

hemoglobin concentration (Hb %), red blood cells (RBCs), white blood cells (WBCs), platelet count.

• Renal function
• Cystoscopy and pathological

examination.

3-       Radiological investigations:

• Computed Tomography (CT) by MDCT Canon Aquilion prime SP 160 sclice scanner witch a maximum rating output of X-ray of 120 KV -600 mA.
• Contrast material diffused by Medrad Slaint
• Analyzing CT images in axial plane, coronal plane and sagittal plane.
• Comparing enhancement pattern of four phases (UP, CMP, NP and EP) for detection of bladder lesion.

Data management and Statistical Analysis:

All data were collected, tabulated and statistically analyzed using statistical package of special science SPSS version 26 statistical package software (IBM; Armonk, New York, USA) as following:

1. Editing and
2. Data entry in computer.
3. Numerical data were presented as mean, standard deviation (SD), median & interquartile range. Mann Whitney test were used for statistical analysis for non- parametric
4. Categorical data were presented as numbers and
5. The chi-squared test and fisher exact were used for statistical
6. Correlations was made to the study in comparing numerical
7. All statistical comparison were two tailed with significance level of p-value ≤ 05 indicates significant, p- value 0.05 indicates non-significant difference

Results

This study included 25 patients referred to radiology department, El Minia oncology institute, from March 2023 to October 2023. All patients were suspected to have UB lesion. The age of the patient ranged between 20-84 years (mean age was 63.08 ± 14.5). The mean age of males was (64.18 ± 14.18) and the mean age of females was (60.75 ± 16.02).

Discussion

According to (Ibrahim J et al., 2023) UBC become common and presents a serious public health concern around the world. In 2020, there were 213,000 deaths and 573000 new cases of the disease. The developed countries exhibited the highest incidence rates. According to predictions of UBC incidence (based only on changes in population), Africa is expected to face the largest percentage growth in incident BC patients from 2020 to 2040 (101%). also, UBC remained the second most common cancer among Egyptian males. UBC has a 4:1 male to female ratio, with a significant male preponderance. This might be because male farmers who are more exposed to the Nile water have greater incidence of Schistosomiasis hematobium also because tobacco smoking.⁽¹⁰⁾

The aim of our research was to investigate the role of CMP in increasing the sensitivity of standard CTU in detecting of UBC with high accuracy specially small and flat lesion, which may be missed due to blooming effect in EP.

This is a prospective cohort study performed on 25 suspected urinary bladder cancer patients were referred from department of radiology at Minia Oncology Center

In our current study, the studied their age from 20 to 84 years with the mean age of (63.08) years ± standard deviation (14.5). The study included 17 male (68%) with mean (64.18) years ± standard deviation (14.18) and 8 female (32%) with mean age of (60.75) years ± standard deviation (16.02).

The results are in agreement with (Zaho X et al., 2022) who concluded that the percentage of BC risk attributed to nonsmoking patients were estimated to be 44%. ⁽¹¹⁾ However (Jacoub L et al., 2018) found that approximately 50% of BC cases are caused by tobacco smoking while our results were 56% of patient are smoking. ⁽¹²⁾

Our study included 76 % of patient presenting with painless hematuria, 12% dysuria 8 % urgency and symptoms 4% flank pain which approximately agree with (Hisham H et   al., 2021) who recorded that more than 80% of patients present with, which is the most common presenting symptom. In addition, 20 % of patients have others symptoms such dysuria, urgency and flank pain and may also present alone without hematuria such as ⁽¹³⁾ According to (Biardeau X et al., 2017) The American Urological Association (AUR) and the American College of Radiology (ACR) both recommended the use of CTU and cystoscopy for the examination of hematuria. The cornerstone of UBC diagnosis and follow-up is cystoscopy. However, it is expensive, invasive and time-consuming procedure, which may cause pain when urination, increases frequency of urination, visible hematuria, UTIs, and has a low reported sensitivity for the detection of UB tumors due to small or flat tumors such as Tis may remain undetected. Additionally, cystoscopy has difficulty distinguishing benign masses from malignant lesions, particularly prior to TURB. ⁽¹⁴⁾

According to (Tony T et al., 2017) CTU performed with three-phase protocol was used which included a non-contrast scan of the abdomen and pelvis followed IV administration of iodinated contrast material then after 100 s a nephrographic scan. Finally  after 10–15 min from administration contrast material excretory phase scan of the abdomen and pelvis. CT urography can be used to detect bladder cancer with a sensitivity of 86%.

⁽¹⁵⁾ While (Lee H et al., 2017) reported in a study of 687 patients, 710 CTU were evaluated to detect UBC. CTU had 91.5% (650/710). ⁽¹⁶⁾

According to (Ola A et al., 2019). CTU is noninvasive, shorter time and wider coverage than cystoscopy so that CTU is the radiologic modality utilized in assessment of patients with UBC. However, it is still limited in the characterization of small UBC ⁽¹⁷⁾. also (Martingano P et al., 2010) reported that UBC less than 1 cm and in those whom recent resection has been performed, are more likely to be falsely negative in CTU also detection is dependent on the morphology and size of the tumor. Therefore, new CTU protocols can eliminate this limitation. ⁽¹⁸⁾

Our results agree with (Ljungberg A et al., 2021) who reported that EP with a small attenuation difference between contrast-enhanced urine and surrounding tissues is preferred, as tiny tumors may be hidden by the contrast blooming effect. Furthermore, since urine containing contrast medium does not easily mix with normal urine, if the patients does not empty bladder prior to the EP, the bladder will be layered with non- enhanced urine anteriorly and contrast-enhanced urine posteriorly, hiding tumors located anteriorly. This is similar to our study, which showed that only 8% of patients had more enhanced in the EP and that 40% of patients had false negative results. ⁽¹⁹⁾

In line with our study (Suleiman A et al., 2022) suggested that CTU containing a corticomedullary phase (CMP) in order to detect UBC with a greater sensitivity which could be similar to cystoscopy.

Also may be eliminate the missing of flat or small tumors by three phases CTU. A four-phase protocol initiated with unenhancement phase (UN) of the abdomen and pelvis then followed by a CMP of the abdomen and pelvis 20 seconds after IV administration of iodinated contrast medium, then nephrographic phase (NP) 40 second after IV administration. Finally excretory phase (EP) of the abdomen and pelvis at least 7.5 min after IV that protocol agree with our study, Additionally, the results showed that the false negative ratio for CTU with CMP were low at 7%, while in our study were 5%. Therefore, in most patients with macroscopic hematuria, cystoscopy may be omitted. ⁽²⁰⁾ Also our results shows that when adding CMP to three phase CTU the sensitivity were 95% while (Helenius M, et al., 2015) reported that the sensitivity were 87 % when adding CMP. ⁽²¹⁾

According to (Andres M et al., 2014) Varia-tions in contrast enhancement were signifi-cant throughout all phases with 88% of cases showing greater contrast enhancement in CMP than other phases while in our study were 84%, this is meaning CMP is preferred for detecting UBC due to its significantly better contrast enhancement compared to NP and EP. ⁽²²⁾

The results agree with (Wolfman J et al., 2020) who recommended that Multiphasic CTU as the first line imaging method in patients with micro-hematuria and suspected with UBC. Which consist of three post-contrastographic phases including corticomedullary (CMP), nephrographic, and excretory phases because of this protocol is also described as the most sensitive for transitional cell carcinomas which agree wit+h our results as (21/25) of our studied patient were TCC and all of them were detected by multiphasic CTU. ⁽²³⁾