Genitourinary Imaging Pictorial Essay Patil et al. PET/CT of Transitional Cell Carcinoma Genitourinary Imaging Pictorial Essay Downloaded from www.ajronline.org by 37.44.193.45 on 01/04/18 from IP address 37.44.193.45. Copyright RRS. For personal use only; all rights reserved Vivek V. Patil 1 Zhen J. Wang Richard. Sollitto Kai-Wen Chuang adrinath R. Konety Randy. Hawkins Fergus V. Coakley Patil VV, Wang ZJ, Sollitto R, et al. Keywords: FDG PET/CT, PET/CT, transitional cell carcinoma DOI:10.2214/JR.08.1945 Received October 14, 2008; accepted after revision June 11, 2009. Z. J. Wang received support for this study from the National Institute of iomedical Imaging and ioengineering (training grant 1 T32 E001631). 1 ll authors: Department of Radiology, University of California San Francisco, 505 Parnassus ve., ox 0628, Rm. M-372, San Francisco, C 94143-0628. ddress correspondence to F. V. Coakley (Fergus.Coakley@radiology.ucsf.edu). WE This is a Web exclusive article. JR 2009; 193:W497 W504 0361 803X/09/1936 W497 merican Roentgen Ray Society 18 F-FDG PET/CT of Transitional Cell Carcinoma OJECTIVE. The objective of this article is to provide a practical illustrated review of PET/CT in the imaging evaluation of transitional cell carcinoma. CONCLUSION. Local evaluation of the primary tumor in patients with transitional cell carcinoma on PET is often limited by the obscuring effect of excreted FDG, but assessment of metabolic activity may still be possible through close correlation with CT images. PET/CT may also be helpful in the detection of disease outside the bladder at nodal or more distant sites and in the assessment of recurrent disease. P ET/CT with 18F-FDG has emerged as a powerful tool for the combined metabolic and anatomic evaluation of many cancers. lthough transitional cell carcinoma accounts for 2% of cancer deaths in the United States, there are relatively few articles in the radiology literature about the utility of PET/CT in this malignancy, possibly because detection of the primary tumor by PET is often difficult due to intense accumulation of excreted FDG in urine [1]. Excreted FDG results in marked uptake throughout the urinary tract and, in addition to obscuring urologic malignancies, such uptake can cause several pitfalls. For example, pooling of FDG in the pelvicaliceal system, in a dilated ureter, or in a bladder diverticulum can be confusing and can falsely suggest pathologic uptake [2]. Excreted FDG activity can be diminished by bladder irrigation or diuresis with furosemide, but such approaches are not part of common practice. CT technique is also an important variable. For example, the routine use of IV contrast material with delayed imaging has been reported to result in a CT sensitivity of 79% for the detection of bladder cancer [3]. The confounding effect of excreted FDG on the visualization of the primary tumor may also be addressed by radiopharmaceuticals such as 11 C choline or 11 C acetate, which are not excreted (Fig. 1), but currently these agents are not readily available. Despite this limitation, we have found that 18 F-FDG PET/CT of transitional cell carcinoma can still be useful in evaluating the primary tumor, distant disease, and recurrence. This pictorial essay aims to provide a practical illustrated review of PET/ CT in the imaging evaluation of transitional cell carcinoma. PET/CT of the Primary Tumor lthough excreted FDG can obscure activity in the primary tumor, particularly if the tumor is small and is confined to the mucosa or wall, careful correlation with CT images may facilitate detection of increased FDG uptake in more advanced transitional cell carcinomas (Fig. 2). Inspection of the coregistered CT images may also allow detection of extravesical extension, which indicates T3b disease (Fig. 3). lthough PET images rarely help in assessing extravesical extension, FDG activity may help in confirming involvement of adjacent organs such as the prostate, vagina, rectum, and uterus, thereby establishing T4a disease. Transitional cell carcinoma can rarely arise within urinary bladder diverticula and is associated with a poorer prognosis due to early tumor invasion through the thin diverticular wall [4] (Fig. 4). Upper tract transitional cell carcinoma may be visible on PET if the size or location of the tumor allows distinction from excreted FDG activity (Fig. 5). PET/CT of Nodal Involvement PET/CT allows the combined anatomic and metabolic evaluation of nodal disease at both regional and distant sites (Figs. 6 and 7). The reported sensitivity and specificity of PET for evaluation of nodal disease JR:193, December 2009 W497
Patil et al. Downloaded from www.ajronline.org by 37.44.193.45 on 01/04/18 from IP address 37.44.193.45. Copyright RRS. For personal use only; all rights reserved in untreated patients with metastatic transitional cell carcinoma are 76.9% and 97.1%, respectively [5]. Sensitivity declines to as low as 50% in patients who have received prior chemotherapy, likely secondary to decreased metabolic activity of treated tumor sites [5]. ccurate assessment of local tumor extent and nodal disease is particularly important in treatment planning. Patients with superficial tumor may be treated with transurethral resection with or without intravesical chemotherapy. Those with more invasive but still localized tumor, such as T2 or T3, benefit from partial or radical cystectomy, or a combination of radiation and systemic chemotherapy. Tumors arising from bladder diverticula are particularly well suited for partial cystectomy. Patients with unresectable tumors (T4b) or local or distant metastases should receive systemic chemotherapy [6]. PET/CT of Distant Disease Distant disease dramatically affects prognosis and management. PET is particularly beneficial when IV iodinated contrast material for CT cannot be administered because of renal insufficiency, which may develop in patients with obstructive bladder cancer (Fig. 8). Common sites of metastatic disease include liver, lung, bone, adrenal gland, and intestine [7] (Fig. 9). Other sites are uncommon but can occur and may be highlighted by FDG avidity (Fig. 10). PET/CT of Recurrent Disease PET/CT has been increasingly used in monitoring patients with treated transitional cell carcinoma of the bladder. PET has particular utility in the evaluation of cases in which interpretation of CT images is complicated by postsurgical and postradiation alterations [8] (Fig. 11). Transitional cell carcinoma has a predilection to seed at sites of intervention and may recur in needle tracks, laparoscopic port sites, and wounds and along drainage tubes, with a reported frequency of 0.1 4% [9, 10] (Fig. 12). The pelvic sidewall is also a common site for recurrent transitional cell carcinoma and should be scrutinized (Fig. 13). Conclusion Local evaluation of the primary tumor on PET is often limited by the obscuring effect of excreted FDG, but assessment of metabolic activity may still be possible through close correlation with CT images. PET/CT may also be helpful in the detection of disease outside the bladder at nodal or more distant sites and in the assessment of recurrent disease. References 1. Purcell DD, Coakley FV, Franc L, Hawkins R, oddington SE, Yeh M. nterior layering of excreted 18 F-FDG in the bladder on PET/CT: frequency and cause. JR 2007; 189:464; [web] W96 W99 2. Shreve PD, nzai Y, Wahl RL. Pitfalls in oncologic diagnosis with FDG PET imaging: physiologic and benign variants. RadioGraphics 1999; 19:61 77 3. Sadow C, Silverman SG, O Leary MP, Signorovitch JE. ladder cancer detection with CT urography in an academic medical center. Radiology 2008; 249:195 202 4. Dondalski M, White EM, Ghahremani GG, Patel SK. Carcinoma arising in urinary bladder diverticula: imaging findings in six patients. JR 1993; 161:817 820 5. Liu IJ, Lai YH, Espiritu JI, et al. Evaluation of fluorodeoxyglucose positron emission tomography imaging in metastatic transitional cell carcinoma with and without prior chemotherapy. Urol Int 2006; 77:69 75 6. Konety R, Carroll PR. Urothelial carcinoma: cancers of the bladder, ureter, & renal pelvis. In: Tanagho E, Mcninch JW, eds. Smith s general urology. New York, NY: McGraw Hill, 2008:308 327 7. Messing E. Urothelial tumors of the bladder. In: Wein J, ed. Campbell-Walsh urology. Philadelphia, P: Saunders Elsevier, 2007:2407 2446 8. Jadvar H, Quan V, Henderson RW, Conti PS. F- 18-fluorodeoxyglucose PET and PET CT in diagnostic imaging evaluation of locally recurrent and metastatic bladder transitional cell carcinoma. Int J Clin Oncol 2008; 13:42 47 9. Micali S, Celia, ove P, et al. Tumor seeding in urological laparoscopy: an international survey. J Urol 2004; 171:2151 2154 10. Elbahnasy M, Hoenig DM, Shalhav, McDougall EM, Clayman RV. Laparoscopic staging of bladder cancer: concerns about port site metastases. J Endourol 1998; 12:55 59 Fig. 1 66-year-old man with newly diagnosed transitional cell carcinoma of bladder. (Courtesy of Heiko Schöder, Memorial Sloan-Kettering Cancer Center), xial contrast-enhanced CT image from staging 11 C-acetate PET/CT study shows nodular mass (arrow) in bladder wall., Fused axial PET/CT image obtained after administration of 20 mci (740 Mq) of 11 C acetate shows that mass (thick arrow) seen in has increased uptake, consistent with malignancy; however, additional increased uptake (thin arrows) is seen along right wall of bladder. Two foci of invasive transitional cell carcinoma were pathologically confirmed. Note that 11 C acetate is not excreted in urine, so evaluation of bladder wall uptake is not confounded by intraluminal activity. W498 JR:193, December 2009
PET/CT of Transitional Cell Carcinoma Downloaded from www.ajronline.org by 37.44.193.45 on 01/04/18 from IP address 37.44.193.45. Copyright RRS. For personal use only; all rights reserved Fig. 2 66-year-old woman with newly diagnosed transitional cell carcinoma of bladder., xial contrast-enhanced CT image from staging PET/CT shows 3-cm polypoid mass (arrow) in bladder., Coregistered axial PET image shows focus (arrow) of increased FDG activity corresponding to mass shown in. In absence of CT image, FDG activity might suggest presence of bladder diverticulum. This case illustrates benefit of careful correlation of CT and PET data sets in patients with transitional cell carcinoma. Fig. 3 74-year-old man with newly diagnosed transitional cell carcinoma of bladder., xial contrast-enhanced CT image from staging PET/CT study shows bladder wall is circumferentially and diffusely thickened due to infiltrative transitional cell carcinoma. In addition, focal extravesical tumor (arrow) is seen protruding on right side of bladder, suggesting extramural extension (T3b disease)., Coregistered axial PET image shows diffuse increased FDG activity (arrow) in thickened bladder wall, based on correlation with CT images, and helps confirm diagnosis of widespread tumor infiltration. However, note resolution of PET image is insufficient to make diagnosis of extramural extension. JR:193, December 2009 W499
Patil et al. Downloaded from www.ajronline.org by 37.44.193.45 on 01/04/18 from IP address 37.44.193.45. Copyright RRS. For personal use only; all rights reserved Fig. 4 65-year-old man with newly diagnosed transitional cell carcinoma arising in bladder diverticulum., xial unenhanced CT image from staging PET/CT study shows subtle soft-tissue mass (arrow) in right-sided diverticulum is associated with focal surface calcification, suggestive of transitional cell carcinoma., Coregistered axial PET image shows diffuse increased FDG activity (white arrow) due to excreted FDG in bladder diverticulum. Tumor (black arrow) is seen as focus of relatively reduced but still above background activity in diverticulum. Cancer can rarely arise within urinary bladder diverticula and is associated with poorer prognosis due to early tumor invasion through thin diverticular wall. Note: ladder had a defect that was digitally corrected; correction is visible in image. Fig. 5 60-year-old man with abnormal urinary cytology and history of bladder cancer treated by transurethral resection and intravesical chemotherapy., xial contrast-enhanced CT image from staging PET/CT study shows that right renal mass (asterisk) due to upper tract transitional cell carcinoma is associated with small perinephric soft-tissue nodule (arrow)., Coregistered axial PET image shows increased FDG activity in renal mass (asterisk) and also in perinephric soft-tissue nodule (arrow), confirming diagnosis of satellite tumor deposit. W500 JR:193, December 2009
PET/CT of Transitional Cell Carcinoma Downloaded from www.ajronline.org by 37.44.193.45 on 01/04/18 from IP address 37.44.193.45. Copyright RRS. For personal use only; all rights reserved Fig. 6 74-year-old man with newly diagnosed transitional cell carcinoma of bladder (same patient shown in Fig. 3)., xial contrast-enhanced CT image from staging PET/CT study shows enlarged left pelvic sidewall node (arrow). ladder wall is circumferentially and diffusely thickened due to infiltrative transitional cell carcinoma., Coregistered axial PET image shows increased FDG activity in enlarged node (arrow) consistent with metastatic involvement. Fig. 7 75-year-old man with transitional cell carcinoma of bladder., xial unenhanced CT image from staging PET/CT study shows enlarged left supraclavicular node (arrow)., Coregistered axial PET image shows increased FDG activity in enlarged node (arrow) consistent with metastatic involvement. Note that node is more conspicuous on PET than CT. JR:193, December 2009 W501
Patil et al. Downloaded from www.ajronline.org by 37.44.193.45 on 01/04/18 from IP address 37.44.193.45. Copyright RRS. For personal use only; all rights reserved Fig. 8 56-year-old man with transitional cell carcinoma of bladder., xial unenhanced CT image from staging PET/CT study shows subtle nonspecific hypodense focus (arrow) in liver. IV iodinated contrast material could not be administered because of elevated serum creatinine level., Coregistered axial PET image shows increased FDG activity (arrow) in hepatic lesion, indicating metastatic spread, which was later confirmed by biopsy, is likely. Fig. 9 78-year-old woman with metastatic transitional cell carcinoma of bladder., xial unenhanced CT image from staging PET/CT study shows large lytic expansile mass (arrow) in left iliac bone., Coregistered axial PET image shows increased FDG activity in mass (arrow), thus confirming diagnosis of metastatic spread to bone. Fig. 10 76-year-old man with transitional cell carcinoma of bladder., xial unenhanced CT image from staging PET/CT study shows enhancing 2-cm soft-tissue nodule (arrow) in left adductor compartment., Coregistered axial PET image shows increased FDG activity in soft-tissue nodule (arrow), indicating probable metastatic disease. Note that node is more conspicuous on PET than CT. W502 JR:193, December 2009
PET/CT of Transitional Cell Carcinoma Downloaded from www.ajronline.org by 37.44.193.45 on 01/04/18 from IP address 37.44.193.45. Copyright RRS. For personal use only; all rights reserved Fig. 11 64-year-old man with dull right lower quadrant pain 2 years after radical cystectomy and ileal conduit formation for treatment of transitional cell carcinoma of bladder., xial contrast-enhanced CT image from PET/CT study shows thick-walled fluid-filled structure (arrow) in right pelvis. Diagnostic considerations based on CT appearance include recurrent tumor or infected segment of conduit., Coregistered axial PET image shows marked increased FDG activity (arrow) in wall of soft-tissue structure, with no excreted FDG activity appearing in contained fluid. ppearance was considered likely due to cavitating tumor recurrence, and this diagnosis was subsequently confirmed by CT-guided biopsy. Fig. 12 70-year-old woman with palpable mass in suprapubic area 3 months after having undergone laparoscopic nephroureterectomy for transitional cell carcinoma., xial contrast-enhanced CT image from PET/CT study shows enhancing 3.5-cm mass (arrow) in subcutaneous tissues at location corresponding to one of laparoscopic port sites., Coregistered axial PET image shows markedly increased FDG activity in mass (arrow). Implantation transitional cell carcinoma metastasis was confirmed at surgical resection. Transitional cell carcinoma has predilection to recur in needle tracks, laparoscopic port sites, wounds, and along drainage tubes. JR:193, December 2009 W503
Patil et al. Downloaded from www.ajronline.org by 37.44.193.45 on 01/04/18 from IP address 37.44.193.45. Copyright RRS. For personal use only; all rights reserved Fig. 13 74-year-old man who presented for follow-up 1 year after having undergone radical cystectomy for transitional cell carcinoma of bladder., xial contrast-enhanced CT image from PET/CT study shows enhancing mass (arrow) abutting left pelvic sidewall., Coronal PET image shows increased FDG activity in mass (arrow), thus confirming diagnosis of recurrence. Pelvic sidewall is common site for recurrent transitional cell carcinoma. W504 JR:193, December 2009