Positron emission tomography in urological oncology

Comparing fluorodeoxyglucose positron emission tomography with computed tomography in staging for nodal and distant metastasis in urothelial/bladder cancer

Objectives

We aim to assess the clinical value of 18F-fluorodeoxyglucose positron (18F-FDG-PET) scan in detecting nodal and distant metastasis compared with computed tomography (CT) scan in patients with urothelial carcinoma or bladder cancer, aiming to improve staging accuracy and thereby better prognosticate and determine therapy.

Methods

A retrospective review of 75 patients with invasive bladder cancer (≥T1) who were staged with both CT and 18F-FDG-PET within an 8-week interval was performed for the period between 2015 and 2020. Seventy-two per cent (54/75) had formal pelvic lymph node (LN) dissection or biopsy of lesions suspicious for metastases. FDG-PET definitions for positive sites were assessed depending on SUV Max (nodes with SUVmax >4 at any size, SUV > 2 for lymph nodes >8 mm, or any SUV if the lymph node was >10 mm on axial images). For CT scanning, enlarged LN by RECIST 1.1 criteria (>10 mm) as well as qualitative findings suggesting metastasis were considered positive. The analysis was based on the comparison of CT and 18F-FDG-PET findings to histopathology results from LN dissection or biopsies.

Results

Sensitivity, specificity, positive predictive values (PPV) and negative predictive value (NPV) of CT versus FDG-PET for detecting metastasis, in patients who underwent pelvic LN dissection or biopsy of lesions suspicious of metastases, were 46.6% (95% CI: 21%-70%) versus 60% (95% CI: 32%-84%), 100% (95% CI: 91%-100%) versus 83.78% (95% CI: 69%-94%), 100% (95% CI: 63%-100%) versus 60% (95% CI: 32%-84%), and 82.2% (95% CI: 68%-92%) versus 83.78% (95% CI: 69%-94%), respectively. 7/75 (9.3%) patients avoided cystectomy due to 18F-FDG-PET features of metastases that were not detected by CT.

Conclusion

FDG-PET may be more sensitive than CT for metastases in the staging of bladder cancer, which resulted in significant avoidance of aggressive local management in cases with occult metastasis.

Role of FDG PET/CT in Management of Patients with Prostate Cancer

Prostate cancer is the second most common cancer in men worldwide. [18F]FDG PET/CT imaging, a well-known and effective technique for detecting malignancies, has not been considered a useful tool for prostate cancer imaging by many because of its perceived low [18F]FDG uptake. Incidentally detected focal [18F]FDG uptake in the prostate is not uncommon, and typically benign. Imaging features that would increase concern for an underlying prostatic carcinoma, include focal uptake in the periphery near the gland margin without calcifications. [18F]FDG PET/CT imaging provides little value in the initial staging of prostate cancer, particularly in the era of prostate specific membrane antigen (PSMA) radiotracer. In cases of biochemical recurrence, the value of [18F]FDG PET/CT increases notably when Grade group 4 or 5 and elevated PSA levels are present. Active research is underway for theranostic approaches to prostate cancer, including [177Lu]Lu-PSMA therapy. Dual tracer staging using FDG and PSMA imaging significantly enhances the accuracy of disease site assessment. Specifically, the addition of [18F]FDG PET/CT imaging allows for the evaluation of discordant disease (PSMA negative/FDG positive). The maximal benefit from [177Lu]Lu-PSMA therapy relies on significant PSMA accumulation across all disease sites, and the identification of discordant disease suggests that these patients may derive less benefit from the treatment. The genuine value of [18F]FDG PET/CT imaging lies in advanced prostate cancer, PSMA-negative disease, as a prognostic biomarker, and the realm of new targeted theranostic agents.

Cavitary lung metastasis as relapse of prostate cancer

Prostate cancer is the most common non-cutaneous malignancy diagnosed in men. It usually metastasizes to bone as osteoblastic lesions on radiographs and regional lymph nodes, and uncommonly to lung, liver and brain. Metastatic prostate cancer recurrence after definitive local therapy can occur in any tissue. The role of fine needle aspiration cytology (FNAC) for diagnosis of metastatic malignancies is well established in literature. We describe a 74 years old male, previously treated for localized prostate cancer, admitted to our Department after total body computed tomography revealed multiple irregular lung lesions some of which had an excavated appearance.

Comparing the Staging/Restaging Performance of 68Ga-Labeled Prostate-Specific Membrane Antigen and 18F-Choline PET/CT in Prostate Cancer: A Systematic Review and Meta-analysis

PURPOSE

PET/CT using prostate-specific membrane antigen (PSMA) and choline radiotracers is widely used for diagnosis of prostate cancer. However, the roles of and differences in diagnostic performance between these 2 radiotracers for prostate cancer are unclear. The aim of this study was to compare the staging and restaging performance of Ga-labeled PSMA and F-choline PET/CT imaging in prostate cancer.

METHODS

A comprehensive search was performed in PubMed for studies reporting the staging performance of Ga-PSMA and F-choline PET/CT in prostate cancer from the inception of the database to October 1, 2018, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. Thirty-five studies were included in this systematic review and meta-analysis. Pooled estimates of patient- and lesion-based sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) for Ga-PSMA and F-choline PET/CT were calculated alongside 95% confidence intervals. Summary receiver operating characteristic curves were plotted, and the area under the summary receiver operating characteristic curve (AUC) was determined alongside the Q* index.

RESULTS

The patient-based overall pooled sensitivity, specificity, PLR, NLR, DOR, and AUC of Ga-PSMA PET/CT for staging in prostate cancer (13 studies) were 0.92, 0.94, 7.91, 0.14, 79.04, and 0.96, respectively, whereas those of F-choline PET/CT (16 studies) were 0.93, 0.83, 4.98, 0.10, 68.27, and 0.95. The lesion-based overall pooled sensitivity, specificity, PLR, NLR, DOR, and AUC of Ga-PSMA PET/CT for staging in prostate cancer (9 studies) were 0.83, 0.95, 23.30, 0.17, 153.58, and 0.94, respectively, and those of F-choline PET/CT (4 studies) were 0.81, 0.92, 8.59, 0.20, 44.82, and 0.98. In both patient- and lesion-based imaging, there was no statistically significant difference in the abilities of detecting or excluding prostate cancer between Ga-PSMA PET/CT and F-choline PET/CT.

CONCLUSIONS

For staging and restaging performance in patients with prostate cancer, there was no significant difference between Ga-PSMA PET/CT and F-choline PET/CT. Ga-PSMA PET/CT and F-choline PET/CT have demonstrated high diagnostic performance for accurate staging and restaging in patients with prostate cancer, and thus both should be considered for staging in this disease.

Is [F-18]-fluorodeoxyglucose FDG-PET/CT better than ct alone for the preoperative lymph node staging of muscle invasive bladder cancer?

Objective:

To evaluate whether the use of [F-18]-FDG-PET/CT can accurately predict pelvic lymph node metastasis in patients with muscle invasive TCC of the bladder undergoing radical cystectomy.

Materials and Methods:

Fifteen patients with muscle invasive bladder cancer had undergone FDG-PET/CT scan from the skull base to the mid-thighs after IV injection of 6.5MBq (Mega-Becquerel)/Kg of FDG. After intravenous hydration IV furosemide was given to overcome the difficulties posed by urinary excretion of 18F-FDG. PET/CT data were analyzed as PET and CT images studied separately as well as fused PET/CT images. The imaging findings were correlated with the histopathology of the nodes (gold standard).

Results:

CT and FDG-PET had demonstrated positive lymph nodes in 9 & 8 patients respectively. Among the 15 patients 3 had documented metastasis on histopathology. Both CT and PET could detect the nodes in all these 3 patients (100% sensitivity). Nodes were histologically negative amongst 6&5 patients who had node involvement by CT and PET respectively. Therefore, specificity, positive predictive value (PPV) & negative predictive value (NPV) for CT and PET/CT were 50%, 33.3%, 100% and 58.3%, 37.5%, 100% respectively.

Conclusion:

The theoretical advantage of this cutting edge technology for whole body imaging has not been translated into clinical practice as we found minimal advantage of combined FDG-PET/CT over CT alone for nodal staging of muscle invasive bladder cancer. This may be due to substantial overlap between standardized uptake values (SUVs) from active inflammatory processes with those of malignant lesion.

Abnormal 18F-FDG uptakes in the prostate due to two different conditions of urine reflux: a mimicker of prostate cancer

A 69-year-old man with lung cancer underwent 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT for staging. FDG PET/CT showed high uptakes in the prostate gland with calcification, and magnetic resonance imaging was recommended to check the prostatic malignancy. T2-weighted images revealed midline cystic lesion at the base to midgland level and cystic lesion in right apical peripheral zone. We suspected urine reflux conditions. Voiding cystourethrography demonstrated those cystic lesions were communicating with the urethra. Therefore these lesions were diagnosed as the prostatic utricle cyst and the dilated prostatic duct in peripheral zone. We conclude that the urine reflux condition should be recognized as a prostate benign lesion with FDG accumulation.

Incidental abnormal FDG uptake in the prostate on 18-fluoro-2-deoxyglucose positron emission tomography-computed tomography scans

18-fluoro-2-deoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) scans are commonly used for the staging and restaging of various malignancies, such as head and neck, breast, colorectal and gynecological cancers. However, the value of FDG PET/CT for detecting prostate cancer is unknown. The aim of this study was to evaluate the clinical value of incidental prostate 18F-FDG uptake on PET/CT scans. We reviewed 18F-FDG PET/CT scan reports from September 2009 to September 2013, and selected cases that reported focal/diffuse FDG uptake in the prostate. We analyzed the correlation between 18F-FDG PET/CT scan findings and data collected during evaluations such as serum prostate-specific antigen (PSA) levels, digital rectal examination (DRE), transrectal ultrasound (TRUS), and/or biopsy to confirm prostate cancer. Of a total of 18,393 cases, 106 (0.6%) exhibited abnormal hypermetabolism in the prostate. Additional evaluations were performed in 66 patients. Serum PSA levels were not significantly correlated with maximum standardized uptake values (SUVmax) in all patients (rho 0.483, p=0.132). Prostate biopsies were performed in 15 patients, and prostate cancer was confirmed in 11. The median serum PSA level was 4.8 (0.55-7.06) ng/mL and 127.4 (1.06-495) ng/mL in the benign and prostate cancer groups, respectively. The median SUVmax was higher in the prostate cancer group (mean 10.1, range 3.8-24.5) than in the benign group (mean 4.3, range 3.1-8.8), but the difference was not statistically significant (p=0.078). There was no significant correlation between SUVmax and serum PSA, prostatic volume, or Gleason score. 18F-FDG PET/CT scans did not reliably differentiate malignant or benign from abnormal uptake lesions in the prostate, and routine prostate biopsy was not usually recommended in patients with abnormal FDG uptake. Nevertheless, patients with incidental prostate uptake on 18F-FDG PET/ CT scans should not be ignored and should be undergo further clinical evaluations, such as PSA and DRE.

Four-dimensional MRI of renal function in the developing mouse

The major roles of filtration, metabolism and high blood flow make the kidney highly vulnerable to drug-induced toxicity and other renal injuries. A method to follow kidney function is essential for the early screening of toxicity and malformations. In this study, we acquired high spatiotemporal resolution (four dimensional) datasets of normal mice to follow changes in kidney structure and function during development. The data were acquired with dynamic contrast-enhanced MRI (via keyhole imaging) and a cryogenic surface coil, allowing us to obtain a full three-dimensional image (isotropic resolution, 125 microns) every 7.7 s over a 50-min scan. This time course permitted the demonstration of both contrast enhancement and clearance. Functional changes were measured over a 17-week course (at 3, 5, 7, 9, 13 and 17 weeks). The time dimension of the MRI dataset was processed to produce unique image contrasts to segment the four regions of the kidney: cortex (CO), outer stripe (OS) of the outer medulla (OM), inner stripe (IS) of the OM and inner medulla (IM). Local volumes, time-to-peak (TTP) values and decay constants (DC) were measured in each renal region. These metrics increased significantly with age, with the exception of DC values in the IS and OS. These data will serve as a foundation for studies of normal renal physiology and future studies of renal diseases that require early detection and intervention.

PET/CT imaging in cancer: current applications and future directions

Positron emission tomography (PET) is a radiotracer imaging method that yields quantitative images of regional in vivo biology and biochemistry. PET, now used in conjunction with computed tomography (CT) in PET/CT devices, has had its greatest impact to date on cancer and is now an important part of oncologic clinical practice and translational cancer research. In this review of current applications and future directions for PET/CT in cancer, the authors first highlight the basic principles of PET followed by a discussion of the biochemistry and current clinical applications of the most commonly used PET imaging agent, (18) F-fluorodeoxyglucose (FDG). Then, emerging methods for PET imaging of other biologic processes relevant to cancer are reviewed, including cellular proliferation, tumor hypoxia, apoptosis, amino acid and cell membrane metabolism, and imaging of tumor receptors and other tumor-specific gene products. The focus of the review is on methods in current clinical practice as well as those that have been translated to patients and are currently in clinical trials.

Patterns of recurrence and surveillance strategies for renal cell carcinoma following surgical resection

Renal cell carcinoma (RCC) remains one of the most lethal urologic malignancies, with up to 40% of patients eventually dying of cancer progression. Despite advances in the diagnosis, staging and treatment of patients with RCC, approximately a third of patients who undergo surgery for clinically localized RCC will suffer a recurrence. Timely identification of recurrences following surgical extirpation is imperative in the treatment of these patients. RCC is known to metastasize through hematogenous routes of spread to distant organ sites and via lymphatic channels to regional lymph nodes. The path of tumor escape is associated with diverse clinical outcomes and a unique tumor biology. A consensus on surveillance regimens for patients following surgical resection of localized disease is lacking. The most extensively used system for providing prognostic information regarding survival and recurrence of disease has historically been the tumor-node-metastasis (TNM) classification system. As a result, most contemporary surveillance protocols have tailored follow-up regimens according to stage-based stratifications. Numerous studies have recently demonstrated that certain clinical and histopathological factors can improve the prediction of tumor recurrence. The incorporation of these prognostic factors into stage-based stratification models should be better than stage alone in attempting to provide a rational approach to identifying treatable recurrences while minimizing unnecessary exams and tests, as well as patient anxiety. Advances in the understanding of the pathogenesis, behavior and molecular biology of RCC have paved the way for developments that may enhance early diagnosis and prognostication, and improve survival for patients. Lastly, molecular markers should, in the future, revolutionize surveillance protocols for RCC by tailoring follow-up to specific molecular classifications.

Gene therapy with HSV1-sr39TK/GCV exhibits a stronger therapeutic efficacy than HSV1-TK/GCV in rat C6 glioma cells

Although the combination of herpes simplex virus type 1 (HSV-1) thymidine kinase (TK) with ganciclovir (GCV) has been shown as a promising suicide gene treatment strategy for glioma, the almost immunodepressive dose of GCV required for its adequate in vivo efficacy has hampered its further clinical application. Therefore, In order to reduce the GCV dose required, we aim to compare the therapeutic efficacy of HSV1-sr39TK, an HSV1-TK mutant with increased GCV prodrug catalytic activity, with wildtype TK in C6 glioma cells. Accordingly, rat C6 glioma cells were first transfected with pCDNA-TK and pCDNA-sr39TK, respectively, and the gene transfection efficacy was verified by immunocytochemistry and western blot analysis. Then the in vivo sensitivity of these transfected C6-TK and C6-sr39TK cells to GCV was determined by 3-(4,5)-dimethylthiahiazo-(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) colorimetric assay and Hoechst-propidium iodide (PI) staining. Finally, a subcutaneously C6 xenograft tumor model was established in the nude mice to test the in vitro efficacy of TK/GCV gene therapy. Our results showed that, as compared with wildtype TK, HSV1-sr39TK/GCV demonstrated a stronger therapeutic efficacy against C6 glioma both in vitro and in vivo, which, by reducing the required GCV dose, might warrant its future use in the treatment of glioma under clinical setting.

Metastatic lung nodule diagnosed on 18F-FDG PET/CT-guided fine needle aspiration in a patient with renal cell carcinoma

Computed tomography (CT)-guided fine-needle aspiration cytology is an essential procedure in establishing the malignant nature of either primary or metastatic lung nodules. However, false-negative findings may result from aspiration of low-cellular areas because true metabolic and cellular tumor volume cannot be identified by anatomic imaging alone. The authors describe a case of renal cell carcinoma with a lung nodule where the highly metabolic intratumoral area was demonstrated on FDG PET/CT, after which the PET/CT-guided fine-needle aspiration cytology established the malignant nature of the nodule.

Is further evaluation needed for incidental focal uptake in the prostate in 18-fluoro-2-deoxyglucose positron emission tomography-computed tomography images?

OBJECTIVE

The aim of this study was to investigate the frequency of secondary evaluation to detect prostate cancer that was primarily manifested as abnormal hypermetabolism detected by 18-fluoro-2-deoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT). We also evaluated the association of maximum standardized uptake values (SUVmax) on PET/CT with clinicopathologic results.

MATERIALS AND METHODS

We evaluated PET/CT reports from a total of 12,037 patients to find cases with abnormal prostate hypermetabolism. Patients with known prostate cancer or a recent prostate procedure were excluded. We analyzed the frequency of secondary evaluations such as digital rectal exams (DRE), levels of serum prostate-specific antigen (PSA), and/or biopsy to confirm prostate cancer. Biopsied patients were categorized into benign and cancer groups. Clinicopathologic characteristics were compared between the groups.

RESULTS

Among 12,037 PET/CT images, 184 (1.5%) showed abnormal hypermetabolism in the prostate. Secondary evaluation was carried out in 120 patients. Biopsy was performed in 38 patients and prostate cancer was confirmed in 23 patients. The median serum PSA level was 3.2 and 49.7 ng/mL in the benign group and cancer group, respectively. The SUVmax was higher in the cancer group (5.7 ± 5.1) than in the benign group (4.8 ± 2.7), but the difference was not statistically significant (p = 0.37). In the cancer group, a high serum PSA level (≥ 20 ng/mL) was detected in 78.3% of the patients. The Gleason score was 7 in 34.7% and 8-10 in 56.5% of prostate cancer patients.

CONCLUSIONS

Hypermetabolism in the prostate was incidentally detected in 1.5% of patients, and only 65.2% of these patients underwent further evaluation (DRE and/or serum PSA levels). Among cases of incidentally detected hypermetabolism in the prostate, patients with abnormal findings (DRE and/or PSA levels) showed high positivity by biopsy, and more than two-thirds of the positive biopsies showed significant prostate cancer. Therefore, patients with hypermetabolism in the prostate should not be ignored and should be secondarily evaluated by DRE and PSA level.

Use of [11C]choline PET-CT as a noninvasive method for detecting pelvic lymph node status from prostate cancer and relationship with choline kinase expression

PURPOSE

To evaluate the accuracy and biological basis for [(11)C]choline-PET-CT in the nodal staging of high risk localized prostate cancer patients.

EXPERIMENTAL DESIGN

Twenty-eight patients underwent dynamic [(11)C]choline-PET-CT of the pelvis and lower abdomen prior to extended laparoscopic pelvic lymph node dissection (eLPL). The sensitivity and specificity of [(11)C]choline PET, [(11)C]choline PET-CT, and MRI for nodal detection were calculated. Average and maximal standardized uptake values (SUV(ave), SUV(max)) were compared with choline kinase alpha (CHKα) and Ki67 immunohistochemistry scores.

RESULTS

Four hundred and six lymph nodes (LN), in 26 patients, were assessable. Twenty-seven (6.7%) involved pelvic nodes at eLPL were detected in 9 patients. Seventeen of the 27 involved nodes were subcentimeter. The sensitivity and specificity on a per nodal basis were 18.5% and 98.7%, 40.7% and 98.4%, and 51.9% and 98.4% for MRI, [(11)C]choline PET, and [(11)C]choline PET-CT, respectively. Sensitivity was higher for [(11)C]choline PET-CT compared with MRI (P = 0.007). A higher nodal detection rate, including subcentimeter nodes, was seen with [(11)C]choline PET-CT than MRI. Malignant lesions showed CHKα expression in both cytoplasm and nucleus. SUV(ave) and SUV(max) strongly correlated with CHKα staining intensity (r = 0.68, P < 0.0001 and r = 0.63, P = 0.0004, respectively). In contrast, Ki67 expression was generally low in all tumors.

CONCLUSION

This study establishes the relationship between [(11)C]choline PET-CT uptake with choline kinase expression in prostate cancer and allows it to be used as a noninvasive means of staging pelvic LNs, being highly specific and more sensitive than MRI, including the detection of subcentimeter disease.

Significance of incidental focal uptake in prostate on 18-fluoro-2-deoxyglucose positron emission tomography CT images

To evaluate the clinical significance of incidental focal prostate fluorodeoxyglucose (FDG) uptake, we reviewed 18-F-FDG positron emission tomography (PET)/CT scans from 2003 to 2007 and selected cases with focal FDG uptake in prostate. Cases of known prostate cancer were excluded. The maximum standardised uptake value (SUV(max)), site (central or peripheral) and pattern (discrete or ill-defined) of FDG uptake, calcification (present or absent) and prostate volume (<30 or ≥30 cc) were recorded. The PET/CT findings were correlated with serum prostate-specific antigen (PSA) levels, imaging studies, clinical follow-up and biopsy. Of a total of 5119 cases, 63 (1.2%) demonstrated focal FDG uptake in prostate. Eight cases were lost to follow-up. Among the 55 cases with follow-up, malignancy was confirmed by biopsy in 3 (5.4%). The three malignant cases had SUV(max) values of 3.3, 3.6 and 2.3, and all were noted in the peripheral portion of prostate; two of these cases had a discrete FDG uptake pattern, none had calcification corresponding to the FDG uptake area and one had a prostatic volume greater than 30 cc. The mean SUV(max) of 52 benign cases was 3.2 ± 1.7 and focal FDG uptake was noted in the peripheral portion in 34 (65%), 20 (38%) cases showed a discrete FDG uptake pattern, 35 (67%) were accompanied by calcification and 32 (62%) had a prostatic volume greater than 30 cc. The majority of cases demonstrating focal FDG uptake in prostate were benign and no PET/CT finding could reliably differentiate benign from malignant lesions; however, when discrete focal FDG uptake without coincidental calcification is seen, particularly in the peripheral zone of the prostate, further clinical evaluation is recommended.

Radiosynthesis and pre-clinical evaluation of [(18)F]fluoro-[1,2-(2)H(4)]choline

INTRODUCTION

Choline radiotracers are widely used for clinical PET diagnosis in oncology. [(11)C]Choline finds particular utility in the imaging of brain and prostate tumor metabolic status, where 2-[(18)F]fluoro-2-deoxy-D-glucose ('FDG') shows high background uptake. More recently we have extended the clinical utility of [(11)C]choline to breast cancer where radiotracer uptake correlates with tumor aggressiveness (grade). In the present study, a new choline analog, [(18)F]fluoro-[1,2-(2)H(4)]choline, was synthesized and evaluated as a potential PET imaging probe.

METHODS

[(18)F]Fluorocholine, [(18)F]fluoro-[1-(2)H(2)]choline and [(18)F]fluoro-[1,2-(2)H(4)]choline were synthesized by alkylation of the relevant precursor with [(18)F]fluorobromomethane or [(18)F]fluoromethyl tosylate. Radiosynthesis of [(18)F]fluoromethyl tosylate required extensive modification of the existing method. [(18)F]Fluorocholine and [(18)F]fluoro-[1,2-(2)H(4)]choline were then subjected to in vitro oxidative stability analysis in a chemical oxidation model using potassium permanganate and an enzymatic model using choline oxidase. The two radiotracers, together with the corresponding di-deuterated compound, [(18)F]fluoro-[1-(2)H(2)]choline, were then evaluated in vivo in a time-course biodistribution study in HCT-116 tumor-bearing mice.

RESULTS

Alkylation with [(18)F]fluoromethyl tosylate proved to be the most reliable radiosynthetic route. Stability models indicate that [(18)F]fluoro-[1,2-(2)H(4)]choline possesses increased chemical and enzymatic (choline oxidase) oxidative stability relative to [(18)F]fluorocholine. The distribution of the three radiotracers, [(18)F]fluorocholine, [(18)F]fluoro-[1-(2)H(2)]choline and [(18)F]fluoro-[1,2-(2)H(4)]choline, showed a similar uptake profile in most organs. Crucially, tumor uptake of [(18)F]fluoro-[1,2-(2)H(4)]choline was significantly increased at late time points compared to [(18)F]fluorocholine and [(18)F]fluoro-[1-(2)H(2)]choline.

CONCLUSIONS

Stability analysis and biodistribution suggest that [(18)F]fluoro-[1,2-(2)H(4)]choline warrants further in vivo investigation as a PET probe of choline metabolism.

Functional imaging of renal cell carcinoma

The incidence of early and advanced-stage renal cell carcinoma (RCC) is increasing. Methods of diagnosing, staging and evaluating tumor burden that are more accurate and reliable than the currently available options are needed in order to identify RCC at a stage at which it is curable and to accurately determine the response to treatment. Functional imaging, particularly with combined PET-CT, might improve accuracy of detection and provide essential information that has been unavailable to date. This approach is against a background in which targeted therapies for metastatic RCC have entered clinical practice in the past few years, further highlighting the importance of accurate imaging for patient selection and for monitoring response to treatment. We outline the current clinical status of functional imaging in RCC using PET-CT, which allows simultaneous capture and co-registration of functional and anatomical data. New radiotracers and approaches-including radiolabeled monoclonal antibodies and imaging of tumor hypoxia-are touched on, and areas of future research discussed.

[Usefulness of PET scans in diagnosing recurrent prostate cancer. Prostate with PSA level < 5 ng/ml]

INTRODUCTION AND OBJECTIVES

We intend to evaluate the usefulness of PET scans in diagnosing recurrent prostate cancer after a curative attempt using radical treatment.

MATERIAL AND METHODS

92 consecutive prostate cancer patients in biochemical progression following radical surgery (63) or radiation treatment (29) were studied with positron emission tomography (PET). In all cases two scans were performed in the same day (11C-choline and 18F-FDG). PET efficacy was evaluated both globally (by employing the results achieved with both 11C-choline and 18F-FDG) and using both radiotracers independently to detect recurrence in patients with biochemical progression. For this purpose, we used comparison of means for k-independent samples, 2 x 2 and 2 x X contingency tables and ROC curves.

RESULTS

1. Global PET: there is evidence of PET alteration regarding the PSA level (P=.003): the clinical stage (P=.01). There are no statistically significant PET alterations regarding the affected biopsy (uni or bilateral), surgical margins, pathological stage and time to progression. ROC curve PET-PSA is statistically significant (P< .0001) permitting calculation of different cut-off points, with a specificity of 91% (highest) for a PSA of 4.3 ng/ml. 2. PET 18FDG: the area under the ROC curve is statistically significant (P< .0001) with a specificity of 91% for a PSA of 6.51 ng/ml. 3. PET 11choline: the area under the ROC curve is statistically significant (P< .0001) with a specificity of 91% for a PSA of 5.15 ng/ml.

CONCLUSIONS

PET is a useful tool for diagnosing prostate cancer recurrence after a curative attempt using radical treatment.

Evaluation of Fluorodeoxyglucose Positron Emission Tomography Imaging in Metastatic Transitional Cell Carcinoma with and without Prior Chemotherapy

INTRODUCTION

This study was designed to determine the value of fluorodeoxyglucose (FDG) positron emission tomography (PET) in the evaluation of metastatic transitional cell carcinoma (TCC).

METHODS

Fifty-eight FDG PET scans were performed on 46 consecutive patients with TCC. Results were correlated with radiologic, pathologic, and histologic findings in these patients and the sensitivity of PET for detecting malignancy in untreated TCC patients (n = 48) was compared to the sensitivity in patients who had undergone prior chemotherapy (n = 10).

RESULTS

Of 48 scans in patients who had no prior systemic chemotherapy, 10 had increased uptake in proven metastatic TCC lesions and 3 PET studies failed to reveal metastatic TCC (sensitivity 76.9%). In patients free of metastatic disease, 33 revealed no abnormal uptake and 1 study revealed a suspicious area in a patient free of metastases (specificity = 97.1%). However, in 10 patients imaged after receiving chemotherapy, the sensitivity fell to 50% for the detection of histologically confirmed residual/recurrent tumor by PET.

CONCLUSIONS

FDG PET detects increased metabolic activity. After chemotherapy, viable cancer cells may still be present but with a diminished metabolic rate. As a result, PET imaging is often useful in the evaluation of untreated metastatic TCC metastasis but should be interpreted with caution in patients who have received prior chemotherapy.

Significance of 18F-fluorodeoxyglucose positron-emission tomography/computed tomography for the postoperative surveillance of advanced renal cell carcinoma

OBJECTIVES

To evaluate the role of (18)F-fluorodeoxyglucose (FDG) positron-emission tomography (PET)/computed tomography (CT) for the surveillance of patients with renal cell carcinoma (RCC) who have a high risk of local recurrence or distant metastasis, by comparing the results with those of conventional imaging methods.

PATIENTS AND METHODS

Sixty-three patients with RCC had conventional imaging studies and FDG PET/CT during the follow-up after surgical treatment. Their pathological stages were T2 in 28 patients, T3a in 14, T3b in 19 and T4 in two; lymph-node or distant metastases were present in 12 patients. Suspicious recurrent or metastatic lesions were confirmed by histopathology or by clinical follow-up. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of conventional surveillance methods and FDG PET/CT were analysed. The difference in the accuracy of FDG PET/CT by nuclear grade and histological subtype of tumours was also assessed.

RESULTS

The FDG PET/CT accurately classified the presence of a recurrence or metastasis in 56 (89%) patients. FDG PET/CT had an 89.5% sensitivity, 83.3% specificity, 77.3% positive predictive value, 92.6% negative predictive value, and 85.7% accuracy in detecting recurrence or metastasis, which was not significantly different from the results with conventional methods. Moreover, the accuracy of the FDG PET/CT by nuclear grade and histological subtypes was not significantly different.

CONCLUSION

For the surveillance of high-risk RCC, FDG PET/CT had results that were as good as conventional methods and were not influenced by the nuclear grades of cancer cells. In addition, it was possible to examine all organ systems in one procedure, and there was no need for contrast agents, that can damage renal function. Therefore, FDG PET/CT might replace conventional methods.

The potential of nanoparticle-enhanced imaging

Accurate lymph node staging in genitourinary malignancy is an important component in the diagnostic algorithm and therapeutic planning. A promising new method for lymph node staging is lymphotrophic nanoparticle enhanced magnetic resonance imaging. This novel technique uses ultrasmall superparamagnetic iron oxide particles, which localize in lymph nodes and provide detailed characterization of these nodes independent of typically accepted size criteria. This review provides a brief overview of the presently accepted methods for noninvasive lymph node staging and thoroughly discusses lymphotrophic nanoparticle enhanced MR imaging: a technique that can be used for accurate detection of lymph node metastases and will likely play a major role in noninvasive lymph node staging in genitourinary cancer in the near future.

The value of 18F-choline PET/CT in patients with elevated PSA-level and negative prostate needle biopsy for localisation of prostate cancer

PURPOSE

Patients with persistent elevated PSA and repeated negative prostate biopsy, that means having the prostate biopsied at multiple times, were investigated with 18F-choline PET/CT to delineate prostate cancer and guide renewed prostate biopsy.

METHODS

Twenty patients with elevated PSA and negative prostate biopsies underwent 18F-choline PET/CT. We performed an early examination of the pelvic region 3-5 min after application. After 30 minutes a whole body PET/CT examination was performed. Image analysis was performed visually and by semi-quantitative analysis calculating the maximum standardised uptake value (SUVmax). 18F-choline uptake was defined as focal, multifocal or inhomogeneous. After the 18F-choline PET/CT, all patients underwent a repeated prostate biopsy, and in the cases where a focal or multifocal uptake was found, the biopsy was guided by the result of the examination.

RESULTS

Qualitative image analysis revealed focal 18F-choline uptake in 13 out of 20 patients. In five patients, prostate cancer was revealed by repeated aspiration biopsy. None of the patients with a multifocal or inhomogeneous 18F-choline uptake had a malignant neoplasm in the prostate. Semiquantitative analysis performed with SUVmax was not helpful in the discrimination of malignancy but showed high values also in benign prostate diseases, as well as in normal prostate tissue. The dual-phase protocol delivered no clear benefit in discriminating malignancy from benign alterations.

CONCLUSION

The use of 18F-choline cannot be generally recommended for localising prostate cancer; however, in highly selected patients, we found useful additional information. In 25% of patients, 18F-choline PET/CT allowed the identification of neoplastic prostatic zones.

Tumor-specific positron emission tomography imaging in patients: [18F] fluorodeoxyglucose and beyond

Biochemical and molecular imaging of cancer using positron emission tomography (PET) plays an increasing role in the care of cancer patients. Most clinical work to date uses the glucose analogue [(18)F]fluorodeoxyglucose (FDG) to detect accelerated and aberrant glycolysis present in most tumors. Although clinical FDG PET has been used largely to detect and localize cancer, more detailed studies have yielded biological insights and showed the utility of FDG as a prognostic marker and as a tool for therapeutic response evaluation. As cancer therapy becomes more targeted and individualized, it is likely that PET radiopharmaceuticals other than FDG, aimed at more specific aspects of cancer biology, will also play a role in guiding cancer therapy. Clinical trials designed to test and validate new PET agents will need to incorporate rigorous quantitative image analysis and adapt to the evolving use of imaging as a biomarker and will need to incorporate cancer outcomes, such as survival into study design.

Contemporary imaging modalities for the surveillance of patients with renal cell carcinoma

In recent years, there have been multiple advances in imaging technologies that have improved the surveillance for recurrence of neoplasms. Multidetector row CT and dynamic contrast enhanced MRI now provide excellent anatomic detail and are beginning to show functional detail as the rapid capture of images following contrast administration improves. Positron emission tomography is emerging as a useful tool in evaluating patients with suspected metastatic disease to the abdomen and bone, particularly when combined with CT. The role of ultrasound in the surveillance of renal cell carcinoma is yet unclear, but its role may be expanding with use of newly developed contrast drugs. Herein we review the relevance of these modalities to the follow-up of patients with renal cell carcinoma.

Imaging in genitourinary cancer from the urologists' perspective

It is well established that advances in imaging may lead to early cancer detection, more accurate tumour staging and consequently adequate treatment, better monitoring of the disease and enhanced surveillance for recurrences after treatment. This manuscript reviews the current use of imaging in genitourinary cancer and explores the impact of imaging findings in clinical management. Additionally, an effort has been made to present the emerging imaging modalities and also their possible role in diagnosis and treatment of these cancers.

Incidental diagnosis of a PSA-negative prostate cancer by 18FDG PET/CT in a patient with hypopharyngeal cancer

Diagnosis of prostate cancer (PC) still remains critical as non-invasive screening with prostate specific-antigen (PSA) lacks to indicate malignancy of the prostate in some cases. Recent research has shown that clinically meaningful PC can develop in patients with a PSA value <4 ng/ml, frequently defined as upper limit of normal serum PSA levels. Furthermore, both morphological (computed tomography (CT), magnetic resonance imaging, transrectal ultrasound) and functional imaging with (18)fluorodeoxyglucose positron emission tomography (FDG-PET) are associated with several limitations for primary diagnosis of PC. We report a case of an incidentally diagnosed PSA-negative PC by (18)FDG PET/CT in a patient with a previous diagnosis of a hypopharyngeal cancer.

[18F]fluorocholine PET/CT imaging for the detection of recurrent prostate cancer at PSA relapse: experience in 100 consecutive patients

PURPOSE

We evaluated the potential of PET/CT and [(18)F]fluoromethylcholine (FCH) in the assessment of suspected recurrence of prostate cancer after treatment.

METHODS

One hundred consecutive prostate cancer patients with a persistent increase in serum PSA (>0.1 ng/ml) after radical prostatectomy (58 cases), radiotherapy (21 cases) or hormonal therapy alone (21 cases) were investigated. After injection of 3.7-4.07 MBq/kg of FCH, both early (at <15 min) and delayed (at >60 min) PET/CT scans were performed in 43 patients, delayed PET/CT scans in 53 patients and early PET/CT scans in four patients.

RESULTS

Of the 100 patients, 54 (PSA 0.22-511.79 ng/ml) showed positive FCH PET/CT scans. Thirty-seven patients had bone and/or abdominal lymph node uptake, while 17 showed pelvic activity. Malignant disease was confirmed in all but one. Delayed SUV(max) of bone metastases was significantly higher (p<0.0001 by paired t test) than that measured at <15 min, whereas no differences were observed between early and delayed SUVs of malignant lymph nodes or pelvic disease. Forty-six patients (PSA 0.12-14.3 ng/ml) showed negative FCH PET/CT scans. Of the negative PET/CT scans, 89% were obtained in patients with serum PSA <4 ng/ml and 87% in patients with a Gleason score <8. In none of these cases could recurrent tumour be proven clinically during a follow-up of 6 months.

CONCLUSION

FCH PET/CT is not likely to have a significant impact on the care of prostate cancer patients with biochemical recurrence until PSA increases to above 4 ng/ml. However, in selected patients, FCH PET/CT helps to exclude distant metastases when salvage local treatment is intended.

11C-choline positron emission tomography in bladder cancer: Report of four cases

Little work has been done with positive emission tomography (PET) in bladder tumors because high urinary excretion of (18)F-FDG makes visualization of the bladder tumor difficult. (11)C-choline has recently been reported as a new tracer which lacks urinary radioactivity. We report the result of (11)C-choline PET in four patients with invasive bladder tumors. In one case, (11)C-choline PET could detect bladder tumor effectively without urinary activity and bone metastasis despite negative bone scintigraphy. On the other hand, an intense accumulation of the tracer in the bladder hampered the interpretation on PET scanning in three patients. The mechanisms of the (11)C-choline accumulation in the bladder were reported to be due to inflammatory and proliferative changes in the mucosa of the bladder from previous catheterization or other factors. Further study is necessary to prove the value of (11)C-choline PET for detecting primary bladder cancer and bone metastasis.

[PSA recurrence after primary curative therapy--local or systemic? When is a second curative therapy still possible?]

PSA recurrence after primary curative therapy for localized prostate cancer is a common problem. Further curative treatment is only reasonable in the case of local recurrence. Therefore, minimizing the likelihood of metastatic disease is crucial. So far, imaging techniques cannot distinguish between local recurrence and distant metastasis. It is therefore reasonable to orientate on PSA kinetics and pathological criteria. Histologic confirmation of suspected local recurrence after radical prostatectomy before salvage therapy is not required. However, after initial radiation therapy histologic confirmation of suspected isolated local recurrence should be obtained. The optimal treatment for a PSA recurrence depends on the initial therapy and the life-expectancy of the patient.

Evaluation of F-18-labeled amino acid derivatives and [18F]FDG as PET probes in a brain tumor-bearing animal model

2-Deoxy-2-[(18)F]fluoro-d-glucose ([(18)F]FDG) has been extensively used as positron emission tomography (PET) tracer in clinical tumor imaging. This study compared the pharmacokinetics of two (18)F-labeled amino acid derivatives, O-2-[(18)F]fluoroethyl-l-tyrosine (l-[(18)F]FET) and 4-borono-2-[(18)F]fluoro-l-phenylalanine-fructose (l-[(18)F]FBPA-Fr), to that of [(18)F]FDG in an animal brain tumor model.

METHODS

A self-modified automated PET tracer synthesizer was used to produce no-carrier-added (nca) l-[(18)F]FET. The cellular uptake, biodistribution, autoradiography and microPET imaging of l-[(18)F]FET, l-[(18)F]FBPA-Fr and [(18)F]FDG were performed with F98 glioma cell culture and F98 glioma-bearing Fischer344 rats.

RESULTS

The radiochemical purity of l-[(18)F]FET was >98% and the radiochemical yield was 50% in average of 16 runs. The uptake of l-[(18)F]FET and l-[(18)F]FBPA-Fr in the F98 glioma cells increased rapidly for the first 5 min and reached a steady-state level after 10 min of incubation, whereas the cellular uptake of [(18)F]FDG kept increasing during the study period. The biodistribution of l-[(18)F]FET, l-[(18)F]FBPA-Fr and [(18)F]FDG in the brain tumors was 1.26+/-0.22, 0.86+/-0.08 and 2.77+/-0.44 %ID/g at 60 min postinjection, respectively, while the tumor-to-normal brain ratios of l-[(18)F]FET (3.15) and l-[(18)F]FBPA-Fr (3.44) were higher than that of [(18)F]FDG (1.44). Both microPET images and autoradiograms of l-[(18)F]FET and l-[(18)F]FBPA-Fr exhibited remarkable uptake with high contrast in the brain tumor, whereas [(18)F]FDG showed high uptake in the normal brain and gave blurred brain tumor images.

CONCLUSION

Both l-[(18)F]FET and l-[(18)F]FBPA-Fr are superior to [(18)F]FDG for the brain tumor imaging as shown in this study with microPET.

Retroperitoneal lymph node dissection in the treatment of low-stage nonseminomatous germ cell tumors of the testicle: An update

Nonseminomatous germ cell tumors (NSGCT) of the testicle are highly treatable and curable. The evolution of cancer control for this disease has shown an effective integration of medical and surgical approaches over the last 3 decades. Current emphasis in the therapy of NSGCT focuses on minimizing treatment-related morbidity while maintaining consistently high cure rates as previously seen. Retroperitoneal lymph node dissection (RPLND) in experienced hands is a critical component of the treatment armamentarium in this disease. RPLND is an accurate staging tool providing important information to determine the need for chemotherapy. When performed properly, RPLND eliminates the retroperitoneum as a site for relapse, which in turn provides emotional and psychological relief to the patient, and simplifies the follow-up protocol. RPLND alone can also provide high cure rates in patients with low clinical stage disease and high risk factors, such as lymphovascular invasion or predominance of embryonal histology in the primary tumor. Teratoma is chemoresistant and, when present in the primary tumor of patients with low stage, may be best treated with primary RPLND. Primary chemotherapy in the treatment of low stage NSGCT deserves continual investigation as long-term toxicities become more apparent. Observation is an option for the highly motivated patient but requires a rigorous follow-up schedule to avoid relapse. Laparoscopic RPLND is a viable staging tool; however, oncologic control of the retroperitoneum has not been reliably determined.

11C-Choline Positron Emission Tomography in Prostate Cancer: Primary Staging and Recurrent Site Staging

OBJECTIVES

To evaluate the usefulness of 11C-choline positron emission tomography (PET) for primary staging and re-staging of prostate cancer.

PATIENTS AND METHODS

11C-choline PET, a total of 22 scans, was performed on 13 patients with histologically proven prostate cancer in primary staging (n = 6) and recurrent site staging; following radical prostatectomy (n = 5) and following radiation therapy (n = 3). In 1 patient, 11C-choline PET was performed in both primary staging and re-staging. Also, 3 patients histologically proven to have no malignant prostate were included.

RESULTS

Because urinary 11C-choline activity was low, it did not interfere with the visualization of pelvic structures. 11C-choline PET visualized normal prostate with a mean SUV of 2.99 (range 2.27-3.68) and primary prostate cancer as a hot spot in 5/6 scans with a mean SUV of 4.21 (range 2.99-6.2). In re-staging, 11C-choline PET was true positive in 9/16 scans and true negative in 2/16 scans. 5/16 scans in 2 patients were false negative with negative conventional imaging.

CONCLUSIONS

In primary staging, 11C-choline PET may not be of use because of no reliable differential 11C-choline uptake of BPH and prostate cancer. On the other hand, 11C-choline PET may be of value in recurrent site staging and monitoring for the prostate cancer.

Postradical prostatectomy TRUS-guided anastomotic biopsy. Where do we stand today?

The issue of performing tissue sampling from the vesicourethral anastomotic area postradical prostatectomy (transrectal ultrasound-guided biopsy) after radical surgical treatment of local disease has failed, still remains controversial. We review a selection of articles that evaluate this procedure as well as newer diagnostic modalities and we discuss how this technique may have a position in our treatment dilemmas in cases with biochemical failure of undetermined origin.

Prostate cancer: a comparative study of 11C-choline PET and MR imaging combined with proton MR spectroscopy

PURPOSE

Prostate cancer is difficult to visualise in its early stages using current imaging technology. The present study aimed to clarify the utility of 11C-choline PET for localising and evaluating cancer lesions in patients with prostate cancer by conducting a prospective comparison with magnetic resonance (MR) imaging combined with proton MR spectroscopy.

METHODS

PET and MR imaging combined with proton MR spectroscopy were performed in 20 patients with prostate cancer. Correlations among the metabolite ratio of choline + creatine to citrate (Cho+Cr/Ci) on MR spectroscopy, serum PSA and maximum standardised uptake value (SUVmax) of (11)C-choline were assessed. The location of the primary lesion was assessed by the site of SUVmax and the laterality of the highest Cho+Cr/Ci ratio and confirmed by examination of surgical pathology specimens (n=16).

RESULTS

PET exhibited a diagnostic sensitivity of 100% (20/20) for primary lesions, while the sensitivities of MR imaging and MR spectroscopy were 60% (12/20) and 65% (13/20), respectively. Weak linear correlations were observed between SUVmax and serum PSA (r=0.52, p<0.05), and between SUVmax and Cho+Cr/Ci ratio (r=0.49, p<0.05). Regarding the localisation of main primary lesions, PET results agreed with pathological findings in 13 patients (81%) (kappa=0.59), while MR spectroscopy results were in accordance with pathological findings in eight patients (50%) (kappa=0.11).

CONCLUSION

This preliminary study suggests that 11C-choline PET may provide more accurate information regarding the localisation of main primary prostate cancer lesions than MR imaging/MR spectroscopy. A further clinical study of 11C-choline PET in a large number of patients suspected of prostate cancer will be necessary to determine the clinical utility of 11C-choline PET in patients who clinically require biopsy.

Retroperitoneal lymph node dissection in the treatment of low-stage nonseminomatous germ cell tumors of the testicle

Nonseminomatous germ cell tumors of the testicle are highly treatable and curable. The evolution of cancer control for this disease has demonstrated an effective integration of medical and surgical approaches over the last 30 years. Current emphasis in the therapy of nonseminomatous germ cell tumors focuses on minimizing treatment-related morbidity while maintaining consistently high cure rates. Retroperitoneal lymph node dissection in experienced hands is a critical component of the treatment armamentarium in this disease. Retroperitoneal lymph node dissection is an accurate staging tool that provides important information in determining the need for chemotherapy. When performed properly, retroperitoneal lymph node dissection eliminates the retroperitoneum as a site for relapse, which in turn provides emotional and psychological relief to the patient and simplifies the follow-up protocol. Retroperitoneal lymph node dissection alone can also provide high cure rates in patients with clinical low-stage disease and high-risk factors such as lymphovascular invasion or predominance of embryonal histology in the primary tumor. Teratoma is known to be chemoresistant and, when present in the primary tumor of low-stage patients, may be best treated with primary retroperitoneal lymph node dissection. Primary chemotherapy in the treatment of low-stage nonseminomatous germ cell tumors deserves continual investigation as long-term toxicities become more apparent. Observation is an option for the highly motivated patient, but requires a rigorous follow-up schedule to avoid relapse. Laparoscopic retroperitoneal lymph node dissection is a viable staging tool, however, oncologic control of the retroperitoneum has not been reliably determined.

PSA relapse prostate cancer: the importance of tailored therapy

Prostate specific antigen (PSA) is an invaluable tumor marker in the detection of early prostate cancer as well as a predictor of recurrence after treatment of localized disease. Current practice entails the use of factors such as pretherapy grade, stage and PSA, PSA doubling time, nature of previous therapy and patient age and functional status for a treatment recommendation. For a PSA relapse post radical prostatectomy, radiation therapy to the prostatic fossa is a primary therapeutic consideration. With careful patient selection, about 30 to 40% of patients are rendered disease free using this approach. For patients with radiation therapy as the primary treatment for their prostate cancer, salvage prostatectomy can be considered, but is rarely feasible. Systemic therapy with hormones is standard if patients are not candidates for the above mentioned salvage local therapies or if they relapse after exhaustive local therapies. Unfortunately androgen suppressive therapy is unlikely to induce cure, or prolonged remissions in PSA relapse prostate cancer. The strategy of addition of chemotherapy or biologic therapy to androgen suppressive therapy is under active investigation. The goal of this therapy is to make an impact on the time to progression to metastatic prostate cancer and correspondingly decrease prostate cancer related mortality. Preliminary results of studies incorporating early chemotherapy in combination with androgen suppressive therapy are encouraging, with improvement in time to progression and overall survival. The evaluation of biologic agents and agents with better toxicity profiles is ongoing. This is very important to make therapy widely applicable and to enable prolonged administration especially in a disease such as prostate cancer with a relatively long natural history. Strategies of adjuvant and neoadjuvant therapy in locally advanced prostate cancer are exploring the possibility of reducing the chance of PSA relapse by treating micrometastatic disease. This review discusses the current practices in risk stratification and management of PSA relapse prostate cancer. It also highlights the major clinical trials and areas of active investigation in this field.

European consensus on diagnosis and treatment of germ cell cancer: a report of the European Germ Cell Cancer Consensus Group (EGCCCG)

Germ cell tumour is the most frequent malignant tumour type in young men with a 100% rise in the incidence every 20 years. Despite this, the high sensitivity of germ cell tumours to platinum-based chemotherapy, together with radiation and surgical measures, leads to the high cure rate of > or = 99% in early stages and 90%, 75-80% and 50% in advanced disease with 'good', 'intermediate' and 'poor' prognostic criteria (IGCCCG classification), respectively. The high cure rate in patients with limited metastatic disease allows the reduction of overall treatment load, and therefore less acute and long-term toxicity, e.g. organ sparing surgery for specific cases, reduced dose and treatment volume of irradiation or substitution of node dissection by surveillance or adjuvant chemotherapy according to the presence or absence of vascular invasion. Thus, different treatment options according to prognostic factors including histology, stage and patient factors and possibilities of the treating centre as well may be used to define the treatment strategy which is definitively chosen for an individual patient. However, this strategy of reduction of treatment load as well as the treatment itself require very high expertise of the treating physician with careful management and follow-up and thorough cooperation by the patient as well to maintain the high rate for cure. Treatment decisions must be based on the available evidence which has been the basis for this consensus guideline delivering a clear proposal for diagnostic and treatment measures in each stage of gonadal and extragonadal germ cell tumour and individual clinical situations. Since this guideline is based on the highest evidence level available today, a deviation from these proposals should be a rare and justified exception.

Differentiation of prostate cancer and benign prostatic hyperplasia: the clinical value of 201Tl SPECT--a pilot study

PURPOSE

Thallium-201 (201Tl) is a recognized tumor-imaging agent; however, the usefulness of 201Tl in prostate cancer has not been studied. The purpose of this preliminary study was to evaluate the efficacy of 201Tl single-photon emission computed tomography (SPECT) imaging for differentiating prostate cancer from benign prostatic hyperplasia (BPH).

METHODS

201Tl pelvic SPECT was performed in 10 patients (aged 64-78 years) with biopsy-proven BPH before transurethral resection of the prostate and 15 patients (aged 65-81 years) with biopsy-proven prostate cancer prior to any therapeutic modality or invasive surgical procedures for treatment of their prostate cancer.

RESULTS

From the 15 patients with prostate cancer, 201Tl pelvic SPECT detected prostate cancer in 13 (86.7%) but not in 2 (13.3%) patients with Gleason scores of 5 (2 + 3). In contrast, all 10 patients with BPH (100.0%) had negative results of 201Tl pelvic SPECT.

CONCLUSION

Our study showed that 201Tl pelvic SPECT scan is very helpful in distinguishing between prostate cancer and BPH.