Prospects in radionuclide imaging of prostate cancer

Prostate cancer is the most common malignancy in men in the Western world and represents a major health problem with substantial morbidity and mortality. Sensitivity and specificity of digital rectal examination (DRE) and evaluation of prostate specific antigen (PSA) are excellent methods for diagnosis of prostate cancer, but have limited value for staging. Imaging of prostate cancer has become increasingly important to improve staging and management of prostate cancer patients. Conventional imaging modalities, such as transrectal ultrasound and computed tomography, show limited accuracy for a reliable assessment of prostate cancer. Diagnostic value of magnetic resonance imaging has improved by dynamic contrast enhancement (DCI-MRI) and diffusion-weighted magnetic resonance imaging (DWI). Recently, substantial progress has been made in the development of functional and molecular imaging modalities, such as positron emission tomography using radiolabeled metabolic tracers, receptor-binding ligands, amino acids, peptides, or antibodies. Here, we review the value of these novel radionuclide imaging techniques in the assessment of prostate cancer.     

Results of the American College of Surgeons Oncology Group Z0050 trial: the utility of positron emission tomography in staging potentially operable non-small cell lung cancer

OBJECTIVES: The American College of Surgeons Oncology Group undertook a trial to ascertain whether positron emission tomography with 18F-fluorodeoxyglucose could detect lesions that would preclude pulmonary resection in a group of patients with documented or suspected non-small cell lung cancer found to be surgical candidates by routine staging procedures. METHODS: A total of 303 eligible patients registered from 22 institutions underwent positron emission tomography after routine staging (computed tomography of chest and upper abdomen, bone scintigraphy, and brain imaging) had deemed their tumors resectable. Positive findings required confirmatory procedures. RESULTS: Positron emission tomography was significantly better than computed tomography for the detection of N1 and N2/N3 disease (42% vs 13%, P =.0177, and 58% vs 32%, P =.0041, respectively). The negative predictive value of positron emission tomography for mediastinal node disease was 87%. Unsuspected metastatic disease or second primary malignancy was identified in 18 of 287 patients (6.3%). Distant metastatic disease indicated in 19 of 287 patients (6.6%) was subsequently shown to be benign. By correctly identifying advanced disease (stages IIIA, IIIB, and IV) or benign lesions, positron emission tomography potentially avoided unnecessary thoracotomy in 1 of 5 patients. CONCLUSIONS: In patients with suspected or proven non-small cell lung cancer considered resectable by standard staging procedures, positron emission tomography can prevent nontherapeutic thoracotomy in a significant number of cases. Use of positron emission tomography for mediastinal staging should not be relied on as a sole staging modality, and positive findings should be confirmed by mediastinoscopy. Metastatic disease, especially a single site, identified by positron emission tomography requires further confirmatory evaluation.     

Sinnvolle bildgebende Diagnostik des lokal fortgeschrittenen Prostatakarzinoms

Prostate cancer is one of the principal medical problems facing the male population in developed countries with an increasing need for sophisticated imaging techniques and risk-adapted treatment options. This article presents an overview of the current imaging procedures in the diagnosis of locally advanced prostate cancer. Apart from conventional gray-scale transrectal ultrasound (TRUS) as the most frequently used primary imaging modality we describe computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). CT and MRI not only allow assessment of prostate anatomy but also a specific evaluation of the pelvic region. Color-coded and contrast-enhanced ultrasound, real-time elastography, dynamic contrast enhancement in MR imaging, diffusion imaging, and MR spectroscopy may lead to a clinically relevant improvement in the diagnosis of prostate cancer. While bone scintigraphy with (99m)Tc-bisphosphonates is still the method of choice in the evaluation of bone metastasis, whole-body MRI and PET using (18)F-NaF, (18)F-FDG, (11)C-choline, (11)C-acetate, and (18)F-choline as tracers achieve higher sensitivities.     

Imaging Prostate Cancer: An Update on Positron Emission Tomography and Magnetic Resonance Imaging

Prostate cancer is a common cancer in men and continues to be a major health problem. Imaging plays an essential role in the clinical management of patients. An important goal for prostate cancer imaging is more accurate disease characterization through the synthesis of anatomic, functional, and molecular imaging information. Developments in imaging technologies, specifically magnetic resonance imaging (MRI) and positron emission tomography (PET)/computed tomography (CT), have improved the detection rate of prostate cancer. MRI has improved lesion detection and local staging. Furthermore, MRI allows functional assessment with techniques such as diffusion-weighted MRI, MR spectroscopy, and dynamic contrast-enhanced MRI. The most common PET radiotracer, ¹⁸F-fluorodeoxyglucose, is not very useful in prostate cancer. However, in recent years other PET tracers have improved the accuracy of PET/CT imaging of prostate cancer. Among these, choline (labeled with ¹⁸F or ¹¹C), ¹¹C-acetate, and ¹⁸F-fluoride have demonstrated promising results, and other new radiopharmaceuticals are currently under evaluation in preclinical and clinical studies.     

Update on positron emission tomography for imaging of prostate cancer

Prostate cancer is the most common non‐cutaneous malignancy among men in the Western world, and continues to be a major health problem. Imaging has recently become more important in the clinical management of prostate cancer patients, including diagnosis, staging, choice of optimal treatment strategy, treatment follow up and restaging. Positron emission tomography, a functional and molecular imaging technique, has opened a new field in clinical oncological imaging. The most common positron emission tomography radiotracer, ¹⁸F‐fluorodeoxyglucose, has been limited in imaging of prostate cancer. Recently, however, other positron emission tomography tracers, such as ¹¹C‐acetate and ¹¹C‐ or ¹⁸F‐choline, have shown promising results. In the present review article, we overview the potential and current use of positron emission tomography or positron emission tomography/computed tomography imaging employing the four most commonly used positron emission tomography radiotracers, ¹⁸F‐fluorodeoxyglucose, ¹¹C‐acetate and ¹¹C‐ or ¹⁸F‐choline, for imaging evaluation of prostate cancer.     

The value of nuclear medicine for the diagnosis of spine diseases

Nuclear medicine examinations hold an important position in the diagnosis of diseases of the spine. During the las decade, decisive progress has been made in the field of instrumentation and radiopharmaceutical techniques: the use of high resolution collimators and the introduction of emission computer tomography as examples of improved instrumentation as well as 99m-Technetium red blood cell labelling as a new radiopharmaceutical technique. These present some of the developments responsible for the growing importance of scintigraphical diagnosis. Inflammatory processes of the vertebrae and the surrounding soft tissues can be detected or excluded with high reliability by the use of radionuclide-labelled granulocytes. The important role of bone scintigraphy in the differential diagnosis of neoplastic bone disease relies on its high sensitivity combined with the quantitative analysis of increased bone metabolism. Furthermore, it provides exact information about the extent and a possible metastatic spread of bone tumours. In the field of orthopaedy and surgery, skeletal scintigraphy is of growing importance as a highly sensitive procedure in the detection of special traumatic lesions such as acute vertebral compression fractures and in the follow-up of patients after bone surgical interventions. Despite the progress of other imaging modalities such as computer tomography and magnetic resonance imaging, nuclear medicine today is well-established in the assessment of diseases of the vertebral column. Among all scintigraphical diagnostic procedures, bone scintigraphy and the different techniques of inflammation imaging are of special importance.     

11C-choline positron emission tomography/computerized tomography for tumor localization of primary prostate cancer in comparison with 12-core biopsy

PURPOSE: (11)C-choline positron emission tomography is an innovative imaging technique for prostate cancer. We assessed the sensitivity of positron emission tomography used together with computerized tomography for intraprostatic localization of primary prostate cancer on a nodule-by-nodule basis, and compared its performance with 12-core transrectal biopsy. MATERIALS AND METHODS: In 43 patients with known prostate cancer who had received positron emission tomography/computerized tomography before initial biopsy, we assessed sensitivity of positron emission tomography/computerized tomography for localization of nodules 5 mm or greater (those theoretically large enough for visualization) using radical prostatectomy histopathology as the reference standard. Comparison with transrectal ultrasound guided biopsy was based on sextant assessment of all cancer foci following sextant-by-sextant matching and reconstruction. Sensitivity/specificity of positron emission tomography/computerized tomography and magnetic resonance imaging for prediction of extraprostatic extension was also assessed. RESULTS: Positron emission tomography/computerized tomography showed 83% sensitivity for localization of nodules 5 mm or greater. At logistic regression analysis only nodule size appeared to influence sensitivity. At sextant assessment positron emission tomography/computerized tomography had slightly better sensitivity than transrectal ultrasound guided biopsy (66% vs 61%, p = 0.434) but was less specific (84% vs 97%, p = 0.008). For assessment of extraprostatic extension, sensitivity of PET/CT was low in comparison with magnetic resonance imaging (22% vs 63%, p <0.001). CONCLUSIONS: Positron emission tomography/computerized tomography has good sensitivity for intraprostatic localization of primary prostate cancer nodules 5 mm or greater. Positron emission tomography/computerized tomography and transrectal ultrasound guided biopsy show similar sensitivity for localization of any cancer focus. Positron emission tomography/computerized tomography does not seem to have any role in extraprostatic extension detection. Studies of diagnostic accuracy (as opposed to tumor localization) are needed in patients with suspected prostate cancer to see whether positron emission tomography/computerized tomography could have a role in not selected patients.     

Novel imaging modalities for lymph node imaging in urologic oncology

Accurate lymph node staging in genitourinary (GU) malignancies is important for planning an appropriate treatment and establishing an accurate prognosis. This article discusses the novel imaging techniques for detection of metastases in various GU malignancies, including prostate, bladder, penile, and testicular cancers. Discussion includes nuclear medicine techniques of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT), (11)C-choline and (18)F-choline PET/CT, and ProstaScint scanning, as well as sentinel lymph node mapping. Magnetic resonance (MR) techniques include lymphotropic nanoparticle-enhanced MR imaging and diffusion-weighted MR imaging.     

Radionuclide imaging in the diagnosis and management of orthopaedic disease

Nuclear medicine imaging is often used in the diagnosis and management of several orthopaedic conditions. Bone scintigraphy measures gamma ray emission to detect the distribution of an injected radiolabeled tracer on multiple image projections. In general, this imaging modality has relatively high sensitivity but low specificity in the diagnosis of occult fractures, bone tumors, metabolic bone disease, and infection. Positron emission tomography measures tissue metabolism and perfusion by detecting short half-life positron ray emission of an injected radiopharmaceutical tracer. Historically, positron emission tomography has been used only to monitor bone metastasis and aid in the diagnosis of osteomyelitis; however, this technology has recently been applied to other orthopaedic conditions for which current imaging modalities are insufficient.     

Nuklearmedizinische Diagnostik bei orthopädischen Erkrankungen

Nuclear medicine techniques show metabolic processes, allowing the diagnoses of many bone and joint disorders. For most orthopaedic indications three-phase bone scintigraphy is used, showing inflammatory bone and joint diseases, traumatic and post-operative disorders as well as necrotic or malignant changes. In addition to bone scintigraphy, there are radiopharmaceuticals to depict inflammatory processes. Finally, positron emission tomography is a modern imaging technique used mainly for tumor diagnostics, but also for detection of inflammation.     

Nuclear medicine techniques in the diagnosis of orthopaedic diseases

Nuclear medicine techniques show metabolic processes, allowing the diagnoses of many bone and joint disorders. For most orthopaedic indications three-phase bone scintigraphy is used, showing inflammatory bone and joint diseases, traumatic and post-operative disorders as well as necrotic or malignant changes. In addition to bone scintigraphy, there are radiopharmaceuticals to depict inflammatory processes. Finally, positron emission tomography is a modern imaging technique used mainly for tumor diagnostics, but also for detection of inflammation.     

核医学影像技术在淋巴瘤诊疗中的应用

近年来,功能性显像技术在淋巴瘤诊疗中逐渐占据重要地位。用于淋巴瘤诊疗的核医学影像技术主要包括单光子发射型断层扫描技术（SPECT）、正电子发射型断层显像（PET）、正电子发射型断层/计算机体层摄影术（PET/CT）。67Ga-枸橼酸较早用于诊断淋巴瘤的功能性显像,后逐渐被18F-FDG取代。PET/CT的应用实现了功能影像与解剖影像有机结合及优势互补,对淋巴瘤的定位、定性及分期更准确,在淋巴瘤的诊疗方面显示出重要的临床应用价值。本文对18F-FDG PET及PET/CT在淋巴瘤诊疗方面的应用现状进行综述。     

Salvage-Prostatektomie

Organ-confined prostate cancer can be treated with curative intent by different types of radiotherapy or by radical surgery. Regardless of improvements in radiotherapy about 60% of patients with prostate cancer develop biochemical recurrence (BCR) which is defined by the progressive increase in serum prostate-specific antigen (PSA) and necessitates further diagnostic procedures. If non-organ-confined cancer and metastasis are categorically excluded by cross-sectional imaging using computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography CT (PET-CT) and bone scintigraphy, a prostate biopsy should be performed. Biopsy proven detection of recurrent or persisting prostate cancer after irradiation is essential prior to a salvage prostatectomy. The function of the lower urinary tract should be evaluated prior to surgery. Preoperative PSA measurement is the best prognostic indicator prior to surgery. Salvage prostatectomy in irradiated patients is more challenging and requires extensive skill. The most common complications are incontinence, rectal injury and anastomotic strictures. Both functional and oncologic outcome have improved due to better irradiation techniques and surgical skills. Provided post-radiotherapy recurrence of prostate cancer is diagnosed early enough, curing is possible by salvage prostatectomy.     

Salvage prostatectomy. Principles of diagnostics and operative therapy

Organ-confined prostate cancer can be treated with curative intent by different types of radiotherapy or by radical surgery. Regardless of improvements in radiotherapy about 60% of patients with prostate cancer develop biochemical recurrence (BCR) which is defined by the progressive increase in serum prostate-specific antigen (PSA) and necessitates further diagnostic procedures. If non-organ-confined cancer and metastasis are categorically excluded by cross-sectional imaging using computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography CT (PET-CT) and bone scintigraphy, a prostate biopsy should be performed. Biopsy proven detection of recurrent or persisting prostate cancer after irradiation is essential prior to a salvage prostatectomy. The function of the lower urinary tract should be evaluated prior to surgery. Preoperative PSA measurement is the best prognostic indicator prior to surgery. Salvage prostatectomy in irradiated patients is more challenging and requires extensive skill. The most common complications are incontinence, rectal injury and anastomotic strictures. Both functional and oncologic outcome have improved due to better irradiation techniques and surgical skills. Provided post-radiotherapy recurrence of prostate cancer is diagnosed early enough, curing is possible by salvage prostatectomy.     

Nuclear medicine techniques for the diagnosis and therapy of prostate carcinoma.

Nuclear medicine techniques play an important role in (re)staging and treatment of prostate carcinoma patients. These techniques are reviewed in this paper. For many years, bone scanning has been a valuable tool for the evaluation of bone metastases. Although utilized in a more refined way since the introduction of serum prostate-specific antigen (PSA) measurement, it is still the procedure of choice in patients with higher-grade or higher-stage tumors and elevated or rising PSA levels. Labeled monoclonal antibodies have been found to have some utility in the clinic for the evaluation of disseminated malignant prostate disease and position emission tomography holds promise for the metabolic characterization of prostate cancer. Several agents are available for radionuclide therapy for bone pain palliation in patients with metastasis, improving pain with minimal side effects or discomfort to the patient. Nuclear medicine techniques in prostate carcinoma are far from obsolete. On the contrary, they are evolving and offer unique opportunities for the management of these patients. The bone scan remains useful in well-defined stages of disease, and palliative therapeutic options are evolving. At present, monoclonal antibodies and PET are not very useful in daily clinical practice.     

Bildgebung der Prostata

Prostate cancer is the most common malignancy of men with approximately 32,000 new cases of prostate cancer in Germany and approximately 11,000 men who would die of the disease each year. For early diagnosis of prostate cancer PSA testing is used, whereas at present screening cannot be recommended due to the lack of confirmed medical and economic benefits. Regarding the imaging modalities, ultrasound of the prostate, currently performed in combination with elastography and histoscanning, magnetic resonance imaging of the prostate in combination with endorectal coils and positron emission tomography combined with computed tomography (PET-CT) are the methods of choice. Using these methods benign prostatitis can be differentiated from prostate cancer and staging of the tumor can be accomplished. On the other hand using these imaging methods it is possible to define the dominant intraprostatic lesion with different sensitivities and specificities, which is important for minimally invasive therapeutic strategies.     

Diagnosis and monitoring of urological tumors using positron emission tomography.

The purpose of this article was to critically review the diagnostic value of positron emission tomography (PET) in urological oncology. Urinary tract tumor assessment is hampered by the renal elimination of (18)F-fluorodeoxyglucose (FDG), the most commonly used PET radiopharmaceutical. PET imaging offers no significant benefits over conventional imaging modalities for renal cell and bladder carcinomas. As a result of the low metabolic activity of prostate cancer, PET does not differentiate adequately between adenoma and carcinoma, nor detect local recurrence after radical prostatectomy with sufficient sensitivity. However, lymph node staging with FDG-PET, specifically in bladder cancer, has been shown to have a potential clinical benefit. Further studies are required to determine the clinical value of retroperitoneal lymph node staging and recurrent disease detection in germ cell tumors. Finally, encouraging early results exist for the use of serial PET measurements to predict and assess therapy response to chemotherapy which may also be valuable in urological oncology.     

Szintigraphie/Positronenemissionstomographie

Skeletal scintigraphy and fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) are established nuclear medicine modalities in the diagnosis of soft tissue tumors. Skeletal scintigraphy scans are performed for detection of osseous infiltration by the primary tumor, of bone metastases and planning of magnetic resonance imaging (MRI). The PET/CT technique has a great potential for assessing tumor grade, for accurate N and M staging, treatment monitoring and in biopsy planning. Recurrent tumors can be detected with high sensitivity, particularly if conventional imaging is impaired by metallic implants. According to current guidelines, if a malignant soft tissue tumor is suspected or proven, PET/CT and PET/MRT should be considered even in children and adolescents.     

Bildgebende Diagnostik des fortgeschrittenen Prostatakarzinoms

The diagnostic approach to prostate cancer is still a big challenge for the treating physician. Regarding an individualized and risk-adapted evaluation of different therapeutic options, precise diagnostic tools are crucial to accurately distinguish between localized and advanced prostate cancer. Imaging of advanced prostate cancer is currently changing due to numerous technical innovations. While choline-based hybrid positron emission tomography-computed tomography (PET/CT) has been established as an important diagnostic tool in clinical imaging of advanced prostate cancer, well-investigated methods, such as magnetic resonance imaging (MRI) and bone scintigraphy are currently expanding the diagnostic potential due to technical improvements. The specific use of imaging for advanced prostate cancer may help to offer the patient a well-tailored oncologic therapy. Further research is needed to evaluate whether this individualized therapy can consistently improve the prognosis of patients suffering from advanced prostate cancer.     

Imaging of the head and neck

Imaging is increasingly being used in the evaluation of patients presenting with a neck mass or with a ‘hot’ neck and has an established role in the staging of head and neck cancer. Plain radiographs have a very limited role and the workhorses of neck imaging are ultrasound, computed tomography (CT) and magnetic resonance imaging with an increased demand, more recently, for positron emission tomography-CT. Contrast studies, videofluoroscopy, angiography and nuclear medicine have a limited but important role in selected cases. This article will discuss the role of some of these imaging modalities in evaluating the soft tissues of the neck.