Diagnostic performance of 18F-DCFPyL positron emission tomography/computed tomography for biochemically recurrent prostate cancer and change-of-management analysis

IntroductionConventional imaging (CI) performs poorly to identify sites of disease in biochemically recurrent prostate cancer. ⁶⁸Ga-PSMA-11 positron emission tomography/computed tomography (PET/CT) is most studied but has a very short half-life. This study reports the diagnostic performance of the novel prostate-specific membrane antigen (PSMA) radiotracer ¹⁸F-DCFPyL using real-life data and tumor board simulation to estimate the impact of ¹⁸F-DCFPyL PET on patient management.MethodsNinety-three ¹⁸F-DCFPyL PET/CT scans performed for patients previously treated for prostate cancer with a rising prostate-specific antigen (PSA) were retrospectively compared to contemporary CI and clinical imaging and PSA followups. A chart review was performed to document prior imaging, pathology results, serial serum PSA measurements, and other pertinent clinical data. Clinical utility of ¹⁸F-DCFPyL PET was measured using a simulated tumor board formed by three physicians with extensive prostate cancer experience deciding on management with and without knowledge of PET/CT results.ResultsAt median PSA 2.27 (interquartile rage [IQR] 5.27], 82% of ¹⁸F-DCFPyL PET/CT demonstrated at least one site of disease: non-regional lymph nodes (37% of scans), regional lymph node metastases (28%), local recurrence (27%), and bone metastases (20%), with higher PET positivity at higher PSA. Compared to ¹⁸F-DCFPyL PET/CT, CI showed overall poor performance, with accuracy below 20% for all extent of disease. PET/CT changed management in 44% of cases. The most frequent scenario was a radical change from initiating androgen deprivation therapy (ADT) to stereotactic body radiotherapy (SBRT) of oligo-lesional disease. In univariate and multivariate analysis, no patient characteristic could predict change of management by PET/CT results.Conclusions¹⁸F-DCFPyL significantly outperforms CI in recurring prostate cancer and is likely to impact management.     

A case of prostate cancer diagnosed pathologically by bone metastatic site biopsy

A 61-year-old man consulted our hospital complaining of high prostate specific antigen (PSA) value and difficulty to urinate. Prostate biopsy had been performed at another hospital, but did not reveal cancer. PSA was 18.5 ng/ml. Transrectal ultrasound-guided prostate biopsy was performed, but cancer was not detected. Later, PSA rose rapidly, and findings suggesting bone metastasis at right pubic bone and left sacro-ilial joint were found on computed tomography (CT), bone scintigraphy and magnetic resonance imaging (MRI). A repeat prostate biopsy was performed, but cancer was not detected from the prostate. On right pubic bone biopsy, poorly to moderately differentiated adenocarcinoma was detected. PSA immunohistochemical staining was positive, and the diagnosis was bone metastasis from prostate cancer. After endocrine therapy was started, PSA declined and bone metastasis disappeared on bone scintigraphy.     

Prostate cancer recurrence in patients with negative or equivocal conventional imaging: A role for 18F-fluciclovine-PET/CT in delineating sites of recurrence and identifying patients with oligometastatic disease

IntroductionDespite improvements in overall survival, biochemical recurrence of prostate cancer, characterized by rising prostate-specific antigen (PSA) levels after curative intent primary therapy, remains common. With the advent of highly sensitive molecular imaging, men with limited metastatic disease burden, or oligometastatic prostate cancer, are increasingly being identified. The LOCATE trial (NCT02680041) assessed the impact of positron emission tomography (PET) with ¹⁸F-fluciclovine on management of men with prostate cancer recurrence after curative intent primary therapy and negative/equivocal conventional imaging. Here, we use LOCATE data to characterize the sites of disease recurrence and explore the potential for ¹⁸F-fluciclovine-PET/CT to evaluate oligometastatic disease.MethodsEligible men (≥18 years; prior curative intent treatment of prostate cancer; recurrence based on rising PSA; negative/equivocal conventional imaging) underwent ¹⁸F-fluciclovine-PET/CT according to standard protocols. The primary outcome measure of the LOCATE trial was a revised management plan post-scan. We performed a secondary analysis of the LOCATE imaging data to characterize anatomical sites of disease recurrence and to explore the potential for ¹⁸F-fluciclovine-PET/CT to evaluate oligometastatic disease. Imaging results were stratified by baseline PSA levels and prior treatment(s) and the Fisher exact test used to analyze differences between groups. Oligometastatic disease was defined as 1–5 extraprostatic lesions (≤3 lesions in any single organ system) plus negative prostate/bed imaging (as a surrogate for primary tumor control).ResultsOf 213 enrolled patients, 164 (77%) had undergone prostatectomy as their initial treatment; their median PSA was 0.57ng/ml. For the 49 patients with an intact prostate, the median PSA was 5.5ng/ml. The overall ¹⁸F-fluciclovine-PET/CT detection rate was 57%. Detection rates were 84% in men with intact prostates and 49% in those who had undergone prostatectomy, with the difference being attributable to prostate/bed findings (71% vs. 18%, respectively). The detection rate in lymph nodes was 29% and in bone was 11%. In total, 53/213 (25%) had oligometastatic disease. Twenty (38%) oligometastatic patients had PSA ≤1.0 ng/ml. Forty-two (79%) experienced a change to their management plan following the scan, commonly to target a lesion identified by ¹⁸F-fluciclovine-PET/CT. The majority of management changes (74%) involved a new treatment modality; however, 10 patients (24%) experienced a modification of the existing plan for radiotherapy to incorporate a boost to an area guided by the ¹⁸F-fluciclovine-PET/CT results.ConclusionEven at low PSA levels, ¹⁸F-fluciclovine-PET/CT identified a diverse pattern of recurrence missed with conventional imaging. One-quarter of men had oligometastatic disease, raising the potential for ¹⁸F-fluciclovine-PET/CT to guide targeted treatment of oligometastases.     

Fluorodeoxyglucose positron emission tomography studies in the diagnosis and staging of clinically advanced prostate cancer

OBJECTIVE: To determine the value of 18F-fluoro-2-deoxyglucose (FDG) positron-emission tomography (PET) studies in evaluating patients with advanced prostate cancer. PATIENTS AND METHODS: FDG-PET scans were taken in 30 patients with advanced prostate cancer 1 h after an injection with 555 MBq of FDG. Patients were scanned from the base of the skull to the inguinal region (including the pelvis). They were also assessed by computed tomography (CT) of the abdomen and pelvis, and bone scintigraphy, to evaluate them for metastases. RESULTS: Thirteen patients had locally extensive prostate cancer and 17 had metastatic disease. Twenty of the 30 patients were positive for radioisotope uptake in the prostate or extraprostatically. The patients with PET-detected prostate cancer were untreated (seven), treated hormonally while they had rising PSA levels (eight), or treated hormonally with a detectable but stable PSA (five). The remaining 10 patients were negative for FDG uptake in the prostate or any metastatic sites; these 10 patients were receiving hormone therapy, with undetectable PSA levels. CONCLUSION: FDG-PET imaging is not a useful test in evaluating advanced prostate cancer in patients being treated and who have an undetectable PSA level. Staging of advanced prostate cancer may be enhanced by FDG-PET imaging in patients who are untreated, who have had an incomplete response to therapy, or who have a rising PSA level despite treatment.     

11C-胆碱PET/CT显像在前列腺癌诊断中的应用价值

目的探讨11C-胆碱PET/CT显像在前列腺癌诊断中的临床价值。方法42例PSA升高的可疑前列腺癌患者为研究组,5例浸润性膀胱癌患者为阴性对照组,静脉注射7.4 MBq/kg 11C-胆碱5 min后行仰卧位盆腔PET/CT显像,可疑转移者行全身显像。测量最高标准化摄取值(SUVmax)并计算前列腺病灶与肌肉组织SUVmax的比值T/B。结果经病理证实为前列腺癌者22例,良性前列腺增生(BPH)者25例(含对照组),两者的T/B值分别为4.32±1.35和1.68±1.23.差异有统计学意义(P<0.01)。11C-胆碱PET/CT显像诊断前列腺癌的敏感性为81.8%(18/22),特异性为84.0%(21/25)。PET/CT显示9例前列腺癌患者伴骨和(或)淋巴结及肺转移。22例前列腺癌者SUVmax与PSA值、Gleason评分值无相关性(P>0.05)。结论11C-胆碱PET/CT显像对前列腺癌的诊断有重要价值。     

MRI/PET Imaging in elevated PSA and localized prostate cancer: a narrative review

ObjectiveTo review the recent milestones in MRI and PET based imaging and evaluate their evolving role in the setting of elevated PSA as well as localized prostate cancer.BackgroundThe importance of multiparametric MRI (mpMRI) and PET based imaging for the diagnosis and staging of prostate cancer cannot be understated. Accurate staging has become another significant milestone with the use of PET scans, particularly with prostate specific radiotracers like 68-Gallium Prostate Specific Membrane Antigen (68Ga-PSMA). Integrated PET/MRI systems are commercially available and can be modulated to evaluate the unique needs of localized as well as recurrent prostate cancer.MethodsA literature search was performed using PubMed and Google Scholar using the MeSH compliant and other keywords that included prostate cancer, PSA, mpMRI, PET CT, PET/MRI.ConclusionsmpMRI has now established itself as the gold-standard of local prostate imaging and has been incorporated into international guidelines as part of the diagnostic work-up of prostate cancer. PSMA PET/CT has shown superiority over conventional imaging even in staging of localized prostate cancer based on recent randomized control data. Imaging parameters from PET/MRI have been shown to be associated with malignancy, Gleason score and tumour volume. As mpMRI and PSMA PET/CT become more ubiquitous and established; we can anticipate more high-quality data, cost optimization and increasing availability of PET/MRI to be ready for primetime in localized prostate cancer.     

A case of prostate cancer with cyst formation]

A 73-year-old man with the complaint of dysuria of 2 years' standing was admitted to our hospital for further examination of an intrapelvic cystic mass, 8.6 cm in diameter, detected incidentally by abdominal ultrasonography. The serum concentration of prostate specific antigen (PSA) was elevated to 44.9 ng/ml. Pelvic computed tomography (CT) and magnetic resonance imaging (MRI) revealed a cystic mass with an irregular thick cyst wall posterior to the urinary bladder originating from the prostate. Transrectal needle biopsy presented a moderately differentiated adenocarcinoma of the prostate. The bloody fluid of the cyst obtained by transperineal aspiration contained a significantly increased level of PSA, but no cancer cells were detected by cytological examination. Total prostatectomy was performed under the diagnosis of clinical stage C (cT3N0M0) prostate cancer. Pathological diagnosis was that cancer cells were present in the prostate tissue and had partly infiltrated the cyst wall. These results suggest that the present cyst was associated with the development of prostate cancer as a pseudocyst without an epithelial lining. The patient has remained free from the disease for over ten months. We review 56 cases of this rare condition that have been reported in Japan.     

The positive yield of imaging studies in the evaluation of men with newly diagnosed prostate cancer: a population based analysis

PURPOSE: We determine the positive yield of imaging studies performed on men with newly diagnosed prostate cancer. MATERIALS AND METHODS: A prospective, population based survey was conducted on 3,690 men with prostate cancer diagnosed between October 1, 1994 and October 31, 1995. Cases were identified by the rapid case ascertainment systems used in 6 geographic regions participating in the Surveillance, Epidemiology and End Results Program. Based on information captured in primary medical record reviews we estimated the positive yield of bone scans, computerized tomography (CT) and magnetic resonance imaging. RESULTS: The positive yield of bone scan and CT was less than 5% and 12%, respectively, for all men with prostate specific antigen (PSA) 4 to 20 ng./ml., and less than 2% and 9%, respectively, for those who also had a Gleason score of 6 or less. Only men with PSA greater than 50 ng./ml. and those with Gleason scores 8 to 10 and PSA greater than 20 ng./ml. had positive yields greater than 10% and 20% for bone scan and CT, respectively. CONCLUSIONS: Imaging studies designed to identify metastases and/or extracapsular extension in men with newly diagnosed prostate cancer frequently have a low positive yield. Wide variations exist in the use of imaging studies and are associated with tumor factors, such as Gleason score and serum PSA, and nontumor factors, such as state of residence. More extensive cost-effectiveness analyses are needed to define appropriate guidelines for ordering imaging studies to optimize the positive yield among men with newly diagnosed prostate cancer.     

Imaging of prostate cancer with PET/CT and radioactively labeled choline derivates

PET- and PET/CT using [¹¹C]- and [¹⁸F]-labeled choline derivates are increasingly being used for imaging of prostate cancer. The value of PET- and PET/CT with [¹¹C]- and [¹⁸F]-labeled choline derivates in biochemical recurrence of prostate cancer has been examined in many studies and demonstrates an increasing importance. PET/CT, in comparison to PET, improves especially the lesion localization as well as characterization. Primary prostate cancer can be detected with moderate sensitivity using PET and PET/CT using [¹¹C]- and [¹⁸F]-labeled choline derivates—the differentiation between benign prostatic hyperplasia, prostatitis, or high-grade intraepithelial neoplasia (HGPIN) is not always possible. At the present time, [¹¹C]-choline PET/CT is not recommended in the primary setting but may be utilized in clinically suspected prostate cancer with repeatedly negative prostate biopsies, in preparation of a focused re-biopsy. Promising results have been obtained for the use of PET and PET/CT with [¹¹C]- and [¹⁸F]-labeled choline derivates in patients with biochemical recurrence. The detection rate of choline PET and PET/CT for local, regional, and distant recurrence in patients with a biochemical recurrence shows a linear correlation with PSA value at the time of imaging and reaches about 75% in patients with PSA > 3 ng/ml. Even at PSA values below 1 ng/ml, the recurrence can be diagnosed with choline PET/CT in approximately one-third of the patients. PET and PET/CT with [¹¹C]- and [¹⁸F]-choline derivates can be helpful in the clinical setting for choosing a therapeutic strategy in the sense of an individualized treatment: an early diagnosis of recurrence is crucial to the choice of optimal treatment. Especially important for the choice of treatment is the exact localization of the site of recurrence: local recurrence, recurrence as lymph node metastasis, or systemic recurrence, as it has direct influence on individual therapy. This article reviews the use of PET and PET/CT with [¹¹C]- and [¹⁸F]-labeled choline derivates in prostate cancer imaging with special emphasis on patients with biochemical recurrence. We briefly provide an overview of PET tracers for prostate cancer imaging, the rationale of using choline derivatives for prostate cancer imaging and discuss the contribution of choline PET/CT in patients suffering from prostate cancer with an emphasis on recurrent disease. Furthermore, we provide an outlook on future prospects of choline PET/CT imaging for therapy guidance and monitoring in the framework of therapy individualization.     

Prostatic cancer in a young adult: a report of 2 cases

Patients younger than 45 years with prostate cancer are rare. Between 1999 and 2002, we studied two cases of prostate cancer in men aged under 45 years. Case 1; a 45-year-old man admitted with the chief complaint of urination disorder. Serum level of prostate-specific antigen (PSA) was 5,000 ng/ml or higher. Transrectal needle biopsy of the prostate revealed moderately differentiated adenocarcinoma. Computed tomography (CT) and bone scan showed para-aorta lymph node metastasis and bone metastasis. Hormone therapy was performed. Case 2; a 37-year-old man admitted with the chief complaint of pollakisuria and sense of residual urine. Serum level of prostate-specific antigen (PSA) was 24 ng/ml. Magnetic resonance imaging (MRI) showed that the prostate tumor invaded the bladder wall. Transrectal needle biopsy revealed poorly differentiated adenocarcinoma. Hormone therapy and radiation therapy were performed. Twenty-one cases reported in Japan in addition to the present cases are reviewed.     

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.     

Diagnosis of localized prostate cancer: screening and preoperative staging]

In 712 patients, mapping of the prostate by six systematic ultrasound-guided core biopsies was performed without major side effects using the "biopyt gun". The histologic findings provided data on patients with normal and those with abnormal prostates on digital rectal examination (DRE). Only 3 of 72 (4%) nonurologic patients with normal prostate-specific antigen (PSA; less than 4 ng/ml) had prostate cancer. In patients with firm prostates on DRE and normal PSA, 13 out of 101 (13%) had prostate cancer. In patients in whom PSA was greater than or equal to 4 ng/ml, 92 of 158 (58%) had prostate cancer. In patients with clinical stage B or C and PSA less than 4 ng/ml, 20/56 (36%) had prostate cancer, compared to 155 of 187 (83%) patients with PSA greater than or equal to 4 ng/ml. Transrectal ultrasound (TRUS) seemed not to be useful in screening for prostate cancer, due to its low specificity of 54%, although in patients with clinical stage B or C TRUS identified 157/175 (90%) patients with prostate cancer. For staging prostate cancer we compared in 103 men with pelvic lymph node dissection the value of digital rectal examination, computerized tomography (CT), magnetic resonance imaging (MRI), PAS, TRUS, and random systematic biopsy for identification of lymph-node-positive patients before radical prostatectomy. CT had a sensitivity of only 7% and a specificity of 96% in detecting lymph nodes, whereas MRI had a sensitivity of 50% and a specificity of 100%.(ABSTRACT TRUNCATED AT 250 WORDS)     

A case of prostate cancer with cyst formation

We treated a case of prostate cancer with cyst formation in an 80-year-old Japanese man presenting with constipation. Fist-sized elastic soft mass was palpable by digital rectal examination. Computed tomography and magnetic resonance imaging demonstrated a retrovesical cystic mass arisen from the prostate. Serum prostate-specific antigen (PSA) was elevated to 15.7 ng/ml. Transrectal prostate needle biopsy revealed moderately differentiated adenocarcinoma and puncture of the cyst yielded aseptic bloody fluid. With a clinical diagnosis of prostate cancer (T2b N0 M1b) with cystic formation, hormonal therapy with a luteinizing hormone releasing hormone analogue and bicalutamide significantly lowered the serum PSA level. One year later, the cyst was reduced in volume and constipation had resolved. A total of 57 cases of prostate cancer with cyst formation are reviewed.     

Prostate cancer: Diagnosis and staging

The discovery and the use of serum prostate specific antigen (PSA) has considerably improved the diagnosis of prostate cancer during the past 20 years. Before PSA era, early diagnosis was only based on the digital rectal examination (DRE) of which the Limitations have been evidenced; over half of the tumours diagnosed by such means had already spread out of the prostate and were incurable. Assessment of serum PSA has allowed the diagnosis to be made at an earlier stage of the disease, curable by current treatments. Whichever the diagnostic tools, transrectal ultrasound (TRUS) prostatic biopsies remain necessary for diagnosis ascertainment, taking into account the low specificity of PSA assessment. The feasibility of a diagnosis at an early and curable stage of the disease has logically resulted in screening procedures aimed at reducing the high mortality related to prostate cancer. The numerous publications on prostate cancer screening provide precise information on the accuracy of available diagnostic means (PSA, DRE, TRUS, combined PSA and DRE), on the characteristics of screened tumours (stage and differentiation), and also on the population of men likely to benefit from the screening (age at beginning and end of the screening, frequency of PSA testing, identification of the men with ethnic and/or genetic predisposition). In those early diagnosed prostate cancers, the assessment of loco-regional cancer extension (extracapsular and/or, microscopic nodal involvement), remains unsatisfactory because no imaging technique (ultrasonography, CT scan, MRI,...) allows visualising the tumour itself or microscopic metastases. Nevertheless, the combination of multiple parameters such as DRE data, PSA level, biopsy data and tumour differentiation helps approaching with an increasing precision (nomograms) the true pathologic stage of the disease. Such advances allow distinguishing, among the very heterogeneous group of prostate cancers, tumours that differ from one to another in terms of disease stage, progression and prognosis, which is helpful for the determination of an adapted therapeutic strategy.     

前列腺癌分子影像学的PET研究进展

前列腺癌是男性泌尿系统中最常见的恶性肿瘤。它的生物学行为与临床情况有很大的异质性,这一特点使前列腺癌的早期诊断、鉴别诊断、治疗及预后评价面临挑战。PET是反映肿瘤生物学的一种理想的非侵入性的功能显像方法,目前已有多种分子影像途径及药物用于前列腺癌的定位诊断及疗效监测。本文综述国内外有关前列腺癌分子影像学的最新PET研究进展并展望其发展前景。     

Prostate cancer in a relatively young adult: a case report

We report a case of prostate cancer in a 45-year-old. The patient was found to have an elevated prostate specific antigen (PSA) level at a general health check and was referred to our division. Serum level of PSA was 6.9 ng/ml. Digital rectal examination and magnetic resonance imaging revealed a small nodule on the right lobe. Transperineal needle biopsy of the prostate revealed adenocarcinoma at the bilateral lobe (Gleason score 3+4). Computed tomography and a bone scan showed no evidence of metastasis. The patient was diagnosed as cT2b, NO, MO, and underwent a radical prostatectomy. Patients younger than 45 with prostate cancer are rare, although the incidence of prostate cancer is increasing. Here, 25 cases previously reported in Japan in addition to the present case, are reviewed.     

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.     

Histological verification of 11C-choline-positron emission/computed tomography-positive lymph nodes in patients with biochemical failure after treatment for localized prostate cancer

OBJECTIVES

To evaluate the potential of ¹¹C‐choline‐positron emission tomography (PET)/computed tomography (CT) for planning surgery in patients with prostate cancer and prostate‐specific antigen (PSA) relapse after treatment with curative intent.

PATIENTS AND METHODS

We retrospectively reviewed the charts of 10 patients with PSA recurrence after either external beam radiation (two) or radical retropubic prostatectomy (eight) for prostate cancer, and who had a laparoscopic lymphadenectomy for suspicious lymph nodes detected on ¹¹C‐choline‐PET/CT. The histological results and PET/CT findings were compared.

RESULTS

In all, 22 suspicious lymph nodes were found on PET/CT, and 14 on conventional CT or magnetic resonance imaging. Comparing the conventional imaging showed concordance in 13 lymph nodes. Three of the 10 patients had no metastatic lymph node disease on definitive histology. The mean (sd ) PSA level for these patients was 1.0 (0.4) ng/mL, whereas that in patients with lymph node metastases was 15.1 (9.2) ng/mL (statistically significant difference, P < 0.05). The positive predictive value was seven of 10. All of the patients initially regressed, with PSA increases after lymphadenectomy. Two of the patients are being managed by watchful waiting, two had radiotherapy of the prostate fossa and two had chemotherapy with docetaxel. Four patients were treated by hormone‐deprivation therapy. After a mean (sd ) follow up of 11 (7) months, one patient died, one has PSA progression, but none of those with negative histology has clinical signs of local recurrence.

CONCLUSIONS

¹¹C‐choline‐PET is a valuable tool for detecting recurrent prostate cancer, but the limited positive predictive value should lead to a critical interpretation of the results.     

68Ga-prostate-specific membrane antigen positron emission tomography/computed tomography for patients with favorable intermediate-risk prostate cancer

IntroductionCurrent guidelines do not support the use of pretreatment imaging in patients with favorable intermediate-risk prostate cancer. ⁶⁸Ga-prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) is more accurate than conventional imaging for preoperative staging. We aimed to evaluate whether pretreatment ⁶⁸Ga-PSMA PET/CT is beneficial for identifying pathological lymph node involvement (LNI) and adverse pathology among patients with favorable intermediate-risk prostate cancer.MethodsWe reviewed 88 patients with favorable intermediate-risk prostate cancer who underwent ⁶⁸Ga-PSMA PET/CT prior to radical prostatectomy and lymph node dissection from 2016–2020. The primary endpoint was the presence of pathological LNI. Association between pretreatment characteristics and outcomes were evaluated.ResultsPreoperative ⁶⁸Ga-PSMA PET/CT showed suspicious uptake in lymph nodes in 4/88 patients (5%), hence, 20 patients would need to be scanned to identify a patient with a positive lymph node on imaging. Two patients had pathological LNI, only one of whom showed ⁶⁸Ga-PSMA PET/CT uptake prior to surgery. The sensitivity, specificity, positive predictive value, and negative predictive values of ⁶⁸Ga-PSMA PET/CT for identifying LNI were 50%, 97%, 25%, and 99%, respectively. After surgery, four patients had evidence of prostate-specific antigen (PSA) persistence. The rate of PSA persistence was higher among patients with LNI on preoperative ⁶⁸Ga-PSMA PET/CT (2/4, 50% vs. 2/84, 2%, p=0.009).ConclusionsPreoperative imaging of favorable intermediate-risk prostate cancer patients using ⁶⁸Ga-PSMA PET/CT showed a low yield for identifying patients at higher risk. Consistent with current guidelines, our findings do not support the routine use of PET/CT in this group of patients. Future prospective studies are needed to validate our findings.     

Prostate cancer

Prostate cancer is the most prevalent type of solid malignant tumour among men in UK. The incidence rate each year amongst age standardized males in the UK was 98.3/100,000. Increasing age is the strongest predeterminant for the development of prostate cancer. Virtually all prostate cancers are adenocarcinomas with their differentiation graded by means of the Gleason score. Since there are often no presenting symptoms, diagnosis is usually reliant on investigations such as digital rectal examination (DRE), the serum prostate-specific antigen (PSA) level, PCA3 m-RNA levels and biopsies guided by a trans-rectal ultrasound probe. Staging consists of magnetic resonance imaging or computed tomography for locally advanced disease and/or a bone scan for detection of bony metastases. Management depends largely on the stage of the disease. For localized prostate cancer, radical prostatectomy can offer a potential cure. Side effects include erectile dysfunction and incontinence. Prostate cancer is also radio-sensitive and can be treated by external-beam radiotherapy or brachytherapy. Hormonal therapy, such as luteinizing-hormone-releasing hormone (LHRH) analogues and anti-androgens are used in locally advanced and metastatic disease. Patients may opt for prostate-specific antigen (PSA) surveillance allowing other therapeutic options to be employed if the PSA starts to rise or the tumour progresses locally. Cytotoxic chemotherapy is increasingly being used for hormone escaped/resistant prostate cancer, and other newer treatment options are in the pipeline. The survival rate for all stages of prostate cancer is now extending.