Imaging prostate cancer

In the detection of prostate cancer, the most important role of imaging is ultrasound-guided prostatic biopsy. In the staging evaluation of prostate cancer, each presently used modality--transrectal US (TRUS), MR imaging, CT, nuclear medicine, and positron emission tomography--has advantages and disadvantages. Evidence-based guidelines on the use of CT and nuclear medicine bone scan, in assessing the risk of distant spread of prostate cancer, are available. There is no consensus and there are no guidelines, however, for the use of imaging in the evaluation of prostate cancer local tumor extent. Results on the value of TRUS vary widely, and prospective multicenter studies suggest that TRUS is no better than digital rectal examination in predicting extracapsular extension. MR imaging offers the most promise for local staging of prostate cancer, but it must resolve problems of reproducible image quality and interobserver variability, and it should prove its efficacy in multicenter trials before it can be recommended for general clinical use. The introduction of MR spectroscopic imaging further expands the value of MR imaging, offering anatomic and metabolic evaluation of prostate cancer.     

Value of x-ray computed tomography in evaluating the spread and therapeutic strategy in cancer of the bladder

Fifty four computed (CT) examinations were performed on patients with bladder carcinoma. A pathological assessment was obtained in 24 cases and the accuracy of CT in local staging was 91%. The accuracy of CT in detecting lymph nodes invasion was also 91%. Moreover, CT is helpful in the follow-up of patients under treatment. As it provides a correct pre-therapeutic evaluation in 83% cases, CT appears as an effective examination to perform in the evaluation of bladder carcinoma.     

Radiotherapy planning for simulation of prostate cancer: computerized tomographic scanning vs. conventional radiographic localization

A computerized tomographic localization protocol for prostate cancer treatment planning is described. In 23 patients, this new method is compared to localization using conventional orthogonal radiographic simulation with contrast media in the rectum, bladder, and urethra. Advantages of the CT localization protocol include enhanced ability to delineate the tumor extension, particularly for superior, lateral, anterior, and posterior spread. Accurate CT localization of the inferior border of the target volume has also been demonstrated to be feasible, thereby avoiding the need for invasive urethral, bladder, and rectal manipulations.     

Computed tomography of prostatic and bladder rhabdomyosarcomas

Rhabdomyosarcoma represents the most common soft tissue sarcoma in children. The CT findings in five patients with pelvic rhabdomyosarcoma are reported. In the three male patients the primary tumor originated in the prostate gland whereas in the two female patients the bladder was the primary site. The CT findings in the prostatic tumors included an enlarged, inhomogeneous prostatic mass with invasion of the perirectal fat. In two of these patients there was thickening of the levator ani muscle and one showed tumor invasion through the ischiorectal fossa and sciatic and obturator foramina into the pelvic musculature and bone. In the two patients with bladder tumors, one showed a large mass adjacent to the lateral aspect of the bladder and ascites, suggesting an ovarian primary tumor. The other patient with sarcoma botryoides (a subtype of rhabdomyosarcoma) had a diffusely thickened bladder. Two patients have had a follow-up CT demonstrating tumor regression posttherapy. The characteristically large size of these masses and propensity for local invasion in a young patient are typical features of pelvic rhabdomyosarcoma.     

小儿盆腔及泌尿生殖系横纹肌肉瘤的影像诊断

目的探讨儿童盆腔及泌尿生殖系横纹肌肉瘤(RMS)的尿路造影和CT表现及其诊断价值。资料与方法回顾性分析20例经手术及活检病理证实的原发于盆腔及泌尿生殖系RMS的影像学资料。其中10例经静脉肾盂造影(IVP)检查,3例经膀胱尿道造影(VCUG)检查,10例经CT检查,1例经MRI检查。结果8例膀胱RMS的IVP、CT表现为膀胱内葡萄状充盈缺损,膀胱颈部与耻骨联合间距增宽,VCUG可见肿物延伸至后尿道;4例前列腺RMS表现为后尿道肿物压迫膀胱颈部并使其抬高、环绕尿道的盆底部包块。6例盆腔RMS IVP及CT表现为盆腔包块,压迫膀胱移位、变形,膀胱壁轻度浸润不规则,输尿管下段浸润者可有轻度输尿管及肾盂积水。1例尿道RMS表现为尿道内充盈缺损,1例阴道RMS,IVP表现为膀胱颈部充盈缺损。结论IVP及VCUG能明确诊断原发于膀胱、前列腺、尿道的RMS及上尿路继发病变;CT及MR可进一步了解起自阴道、前列腺、盆腔的RMS及其与周围器官的关系。     

Pelvic adenopathy from bladder and prostate carcinoma: detection by rapid-sequence computed tomography

Diagnostic pelvic lymphadenectomies are used in both bladder and prostate carcinoma. Enhanced rapid-sequence computed tomographic (CT) scanning of the retroperitoneum and pelvis was done prospectively in patients scheduled for lymphadenectomies. The CT results were then compared to the histopathological findings in 32 patients to analyze the ability of dynamic CT to indicate whether a lymphadenectomy is needed. The comparison showed eight true positive, four false negative, 18 true negative, and two false positive. The sensitivity was 66%, specificity 90% and accuracy 81%. The diagnostic considerations of the role of CT based on these findings are illustrated and discussed.     

State-of-the-art cross-sectional imaging in bladder cancer

Advances in cross-sectional imaging have given radiology an increasingly significant role in the diagnosis, staging, and restaging of patients with bladder cancer. The primary role of computed tomography (CT) in bladder cancer is for tumor staging and screening for distant metastases. Multidetector-row CT may improve the evaluation of bladder tumors by overcoming the difficulties of previous generations of CT in detecting invasion of contiguous organs and nodal staging. Magnetic resonance imaging (MRI) however is still considered superior to CT for primary staging of bladder carcinoma. The multiplanar capability of MRI with its superior soft-tissue resolution offers improved evaluation of local staging of bladder tumors. Positron emission tomography/CT is emerging as a novel-imaging tool for the detection of distant metastases. In this review, we emphasize the value of current cross-sectional imaging and discuss the potential applications of novel imaging techniques in the management of patients with bladder cancer, predominantly transitional cell carcinoma.     

MR imaging of bladder neoplasms: Correlation with pathologic staging

This retrospective study describes the accuracy of magnetic resonance (MR) imaging in determination of local disease extent in 34 examinations performed for evaluation of primary or recurrent bladder carcinoma. The 34 examinations were carried out in 29 patients (17 men, 12 women, aged 34-89 years). All studies were followed within 30 days by surgical and pathologic evaluation. Images were interpreted by two radiologists unaware of clinical or pathologic findings. MR imaging staging conformed to the TNM system of the International Union Against Cancer (IUAC). Pathologic evaluation showed bladder neoplasms in all cases; three patients' pathologic specimens contained two or more histologic types of tumors. MR imaging staging of the depth of tumor invasion was correct in 85% of examinations. Sensitivity of MR imaging for detection of deep muscle invasion was 97%, specificity 83%, and accuracy 94%. Sensitivity of MR imaging for detection of extravesical tumor extension was 95%, specificity 100%, and accuracy 97%. Sensitivity for detection of pelvic lymph node metastases was 50%, specificity 100%, and accuracy 82%. Our population included many patients with locally advanced disease. This pattern reflects standards of clinical practice by which superficial lesions are staged and resected endoscopically, and deeply invasive tumors are imaged prior to radical surgery.     

CT在前列腺癌诊断及分期中的价值

目的：探讨CT用于前列腺诊断及分期的价值。方法：回顾分析40例前列腺癌（24例经病理或细胞学证实，16例经临床证实）的CT征象，进行CT分期，12例行MPR重建，参照J-W标准对比CT分期与临床分期，结果：40例前列腺癌，CT表现前列腺正常2例，增大38例；前列腺内局限性病灶17例，病灶结节状，肿块状外突23例；病灶平扫低/低混密度27例（67.5%)/3例（7.5%)，平扫等密度，增强后为低密度10例（25%0；钙化13例，侵及精囊腺，膀胱，直肠，盆腔淋巴结及远处转移各11例，19例，9例、5例、6例，CT复合征象23例（57.5%)。CT分期的总准确率为82.5%,C、D期符合率为90%和66.7%,区分A/B期和C/D期的敏感性90%。结论：CT复合征象对前列腺癌的诊断有较高的特异性。结合3D-MPR有助于定位诊断，CT能较准确的区分A/B期和C/D期肿瘤，对C、D期肿瘤诊断准确性较高。     

Solitary fibrous tumor of the male pelvis: findings at CT with histopathologic correlation

We present CT imaging findings with pathologic correlation in a rare case of a solitary fibrous tumor arising in the pelvis in a 34-year-old man. This tumor presented as a hypervascular heterogeneously enhancing deep pelvic mass at CT. Although CT initially suggested the prostate as the site of origin for this tumor, no prostate involvement was found at surgery; CT accurately excluded bladder and rectal involvement.     

前列腺横纹肌肉瘤的影像学表现分析(附3例报道并文献复习)

目的 探讨前列腺横纹肌肉瘤的影像学表现.资料与方法 回顾性分析3例前列腺横纹肌肉瘤患者的临床及影像学资料并作文献复习.结果 3例表现为前列腺明显增大,伴软组织肿块形成,CT和MR增强后均有明显强化,肿瘤内部有不规则坏死区.DSA造影可见新生肿瘤血管和明显的肿瘤染色征.对盆腔邻近组织、结构仅1例主要表现为膀胱受压,其余均表现为不同程度侵犯,膀胱和精囊腺是极易受侵犯的器官.1例发生肺和盆腔转移.结论 前列腺横纹肌肉瘤常见于青少年,CT和MR能显示前列腺肉瘤的表现以及对邻近结构的侵犯情况.     

Imaging prostate cancer: a multidisciplinary perspective

The major goal for prostate cancer imaging in the next decade is more accurate disease characterization through the synthesis of anatomic, functional, and molecular imaging information. No consensus exists regarding the use of imaging for evaluating primary prostate cancers. Ultrasonography is mainly used for biopsy guidance and brachytherapy seed placement. Endorectal magnetic resonance (MR) imaging is helpful for evaluating local tumor extent, and MR spectroscopic imaging can improve this evaluation while providing information about tumor aggressiveness. MR imaging with superparamagnetic nanoparticles has high sensitivity and specificity in depicting lymph node metastases, but guidelines have not yet been developed for its use, which remains restricted to the research setting. Computed tomography (CT) is reserved for the evaluation of advanced disease. The use of combined positron emission tomography/CT is limited in the assessment of primary disease but is gaining acceptance in prostate cancer treatment follow-up. Evidence-based guidelines for the use of imaging in assessing the risk of distant spread of prostate cancer are available. Radionuclide bone scanning and CT supplement clinical and biochemical evaluation (prostate-specific antigen [PSA], prostatic acid phosphate) for suspected metastasis to bones and lymph nodes. Guidelines for the use of bone scanning (in patients with PSA level > 10 ng/mL) and CT (in patients with PSA level > 20 ng/mL) have been published and are in clinical use. Nevertheless, changes in practice patterns have been slow. This review presents a multidisciplinary perspective on the optimal role of modern imaging in prostate cancer detection, staging, treatment planning, and follow-up.     

Staging of bladder carcinoma: MRI-CT-surgical correlation

Eleven patients with transitional cell carcinoma of the bladder were examined with spin-echo MRI using a superconductive magnet operating at a field strength of 0.35 T. MRI results were compared with the CT findings in 10 of the patients. All subjects later underwent radical cystectomy including pelvic lymph-node dissection. MRI accuracy for staging was 64% using the TNM classification and 73% by the Jewett-Strong-Marshall system while CT accuracy was 40%. MRI provided improved demonstration of tumor invasion of perivesical fat planes, prostate, and seminal vesicles and greater anatomic detail was afforded by direct sagittal and coronal views.     

Colorectal carcinoma evaluation with CT: preoperative staging and detection of postoperative recurrence

CT was performed prior to surgery in 103 patients with colorectal carcinoma to assess its value in staging the tumor. Preoperative IBD scans had sensitivities and specificities of 72.7% and 98.9% in detection of liver metastases, 25.9% and 96% in detection of lymph node metastases, and 61.2% and 80.6% in detection of local extension. Compared with the Duke's classification, CT correctly staged only 47.5% of patients: 16.6% were upstaged, and 83.3% were downstaged. Recurrent tumors developed in 11 of 67 patients followed for more than 24 months. CT depicted recurrence in six patients scanned prior to 12 months. Routine scans obtained at 12 months depicted unsuspected tumor recurrence in three of four patients with proved recurrent disease (one patient with pulmonary metastases did not undergo CT). This study indicates that because of the poor accuracy of CT in preoperative local staging of colorectal carcinoma, it has virtually no useful clinical role in this regard. However, preoperative CT evaluation of the liver can be useful. Routine postoperative CT, combined with fine-needle aspiration biopsy, is useful for detection of recurrent tumor.     

儿童膀胱葡萄状肉瘤的影像诊断（附6例分析）

本文报道６例儿童膀胱葡萄状肉瘤的ＣＴ和膀胱造影表现。膀胱葡萄状肉瘤ＣＴ扫描主要表现为膀胱内软组织密度充盈缺损、膀胱壁增厚以及前列腺等邻近器官受侵。膀胱造影主要表现为息肉状充盈缺损以及膀胱受压、膀胱壁僵硬。结合文献讨论了其Ｘ线诊断以及鉴别诊断。     

MR staging of bladder carcinoma: correlation with pathologic findings

Forty patients with bladder carcinoma were examined preoperatively by means of magnetic resonance (MR) imaging. In all patients, total cystectomy with enterocystoplasty and pelvic node dissection was performed. The surgical and pathologic findings were correlated with the MR findings. Extension through the deep muscle of the bladder wall was present in 20 of the 40 patients and was diagnosed with a sensitivity of 95% and a specificity of 95%. Extension to perivesical fat was present in 18 of 40 patients and was diagnosed with a sensitivity of 66% and a specificity of 100%. Invasion of the adjacent organs was present in nine of 40 patients and was diagnosed with a sensitivity of 44% and a specificity of 96%. On the basis of the MR findings, the tumor was correctly staged, according to the TNM classification, in 24 of 40 (60%) patients, tumor extension was overestimated in three of 40 (7.5%) patients, and tumor extension was underestimated in 13 of 40 (32.5%) patients. MR imaging has been shown to be accurate in identification of macroscopic lymph node involvement and deep muscle involvement. It appears to be at least as useful as computed tomography (CT) in the evaluation of perivesical fat involvement and to be superior to CT in the detection of invasion of adjacent organs. One limitation of MR imaging is in the evaluation of tumor extension into the periurethral glands.     

Soft-tissue sarcomas of the extremities. Their assessment with magnetic resonance

MR imaging was performed on 38 patients with suspected malignant soft-tissue tumors of the extremities. MR diagnostic accuracy was compared with that of other methods. All patients underwent surgical control. In 7 cases MR imaging was employed to demonstrate the tumor response to antiblastic local perfusion. Lesion identification, extension, compartmental evaluation, bone and vascular involvement were the diagnostic parameters considered. In all cases MR imaging detected the lesion, correctly showing the intracompartmental (16 patients) or extracompartmental (22 patients) extension. In 2 out of 6 cases MR imaging did not demonstrate bone invasion, and in 1 case vascular involvement could not be assessed. MR diagnostic accuracy was superior to that of other techniques. Nonetheless, a diagnostic protocol was proposed for the local staging of malignant soft-tissue tumors of the extremities where some diagnostic limitations of MR imaging are taken into account--i.e., inconsistent evaluation of bone and vascular involvement. Plain X-rays and US are the imaging modalities of choice, whereas MR imaging is to be a second-choice diagnostic technique before biopsy. Thus, MR imaging replaces CT, while angiography is to be used in selected cases, where MR imaging is not diagnostic due to vascular involvement.     

Invasive cervical carcinoma: comparison of MR imaging and surgical findings

The accuracy of magnetic resonance (MR) imaging in staging invasive carcinoma of the cervix was determined retrospectively in 57 consecutive patients in whom the extent of disease was surgically confirmed. MR images were analyzed for (a) location and size of the primary tumor; (b) tumor extension to the uterine corpus, vagina, parametria, pelvic sidewall, bladder, or rectum; and (c) pelvic lymphadenopathy. The accuracy of MR imaging in determination of tumor location was 91% and for determination of tumor size within 0.5 cm, 70%. Its accuracy was 93% for vaginal extension and 88% for parametrial extension. Pelvic sidewall, bladder, and rectal involvement were accurately excluded in all patients, but the positive predictive values were 75%, 67%, and 100%, respectively. Overall, the accuracy of MR imaging in staging was 81%. MR imaging is valuable because it can accurately demonstrate tumor location, tumor size, degree of stromal penetration, and lower uterine segment involvement. It is also valuable for ruling out parametrial, pelvic sidewall, bladder, and rectal involvement.     

Nuclear medicine studies of the prostate, testes, and bladder

During the last decade, there has been a significant advancement in imaging of urologic diseases. Transrectal ultrasound (TRUS), computerized tomography (CT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and positron emission tomography (PET) are still experiencing new developments in urology. Despite these many technological advances, the initial diagnostic procedure for a patient with suspected prostate cancer (PC) is multiple site blind prostate biopsies. There is a need for a noninvasive metabolic imaging modality to direct the site of biopsy to decrease the sampling error. MRS seems promising but as it is a costly and more time-consuming test, further studies are needed to evaluate its clinical utility. Currently, PET does not play any role to direct biopsy. Acetate and choline appear to be better tracers than FDG for the detection of a prostate lesion, however, further well-organized studies are needed before any of these agents can be used clinically. Incidental detection of intense focal uptake in the prostate during whole body PET scanning should be evaluated with prostate-specific antigen (PSA) and TRUS-guided biopsy. Although FDG is inferior to other tracers for primary staging, it may be useful in selected patients with suspected high-grade cancer. The role of ProstaScint scan is still controversial for detection of recurrent PC. This study may be helpful for evaluating nodal metastases when PSA is elevated and bone scan is negative. Bone scan remains the study of choice when bone metastases are suspected (PSA>15-20 ng/mL+/-bone pain). Acetate and choline provide better accuracy than FDG in the detection of local soft tissue disease, nodal involvement, and distant metastases. High FDG uptake may be indicative of more aggressive and possibly androgen-independent disease. PET/CT with any of the above PET tracers will most likely be preferred to the PET scan alone due to better localization of a hot lesion in PET/CT. Nuclear medicine studies also have been used to evaluate acute scrotum and testicular neoplasms. Scrotal scintigraphy has lost its popularity to Doppler ultrasound in the evaluation of the acute scrotum. In testicular tumors, FDG-PET appears to be superior to conventional imaging modalities in initial staging, detection of residual/recurrence, and monitoring treatment response. Tumor markers after treatment occasionally are elevated and cannot locate the site of recurrence, FDG-PET can play a very important role in this regard. Nuclear medicine studies also have been used to evaluate diseases of the urinary bladder. Radionuclide cystography is more sensitive and has less than 1/20 the radiation exposure of the conventional contrast enhanced micturating cystourethrogram (MCU). However, the utility of FDG-PET in the evaluation of bladder cancer seems to be limited to the evaluation of distant metastases. 11C-Methionine and choline may be a better option for local and nodal disease due to their negligible excretion in the urine.     

伽玛刀对泌尿系肿瘤的临床疗效分析

目的　观察伽玛刀治疗前列腺癌、膀胱癌及肾癌术后局部复发肿块的治疗效果。方法　应用螺旋CT薄层扫描 ,定位 ,根据肿瘤性质、类型、部位等制订治疗计划 ,应用体部伽玛刀在特定的治疗床上按治疗方案对患者进行治疗。结果　 5例患者中 ,3例晚期前列腺癌伴广泛转移 ,治疗后症状无明显改善 ,1年内相继死亡。 1例膀胱癌周围浸润伴骨转移 ,治疗后症状有所减轻 ,CT示肿块无增大 ,配合化疗。l例左肾癌术后 ,局部肿块复发 ,再手术切除 ,再复发 ,无其他部位转移 ,治疗后疼痛症状很快消失 ,3个月后复查CT示肿块有缩小。结论　伽玛刀治疗肿瘤是一种安全、有效、并发症少的治疗方法 ,对肿瘤较局限、体积较小、无广泛转移者效果更好。