Are Bone Scans Necessary in Men With Low Prostate Specific Antigen Levels Following Localized Therapy?

Hybrid magnetic resonance and PET imaging for prostate cancer recurrence

PURPOSE OF REVIEW

Recurrence post definitive local therapy by prostatectomy or radiation therapy is often detected via rise in serum prostate-specific antigen (PSA) levels; however, PSA rise does not localize the disease. Distinguishing local versus distant recurrence guides whether to choose subsequent local versus systemic therapy. The purpose of this article is to review imaging for prostate cancer recurrence post local therapy.

RECENT FINDINGS

Among imaging modalities, multiparametric MRI (mpMRI) is commonly used to assess for local recurrence. New radiopharmaceuticals target prostate cancer cells and enable whole-body imaging. These tend to be more sensitive for lymph node metastases than MRI or computed tomography (CT) and for bone lesions than bone scan at lower PSA levels but can be limited for local prostate cancer recurrence. Given greater soft tissue contrast, similar criteria for lymph nodes, and greater sensitivity for prostate bone metastases, MRI is advantageous to CT. MRI of the whole body and mpMRI are now feasible within a reasonable time frame and complementary to PET imaging, enabling whole-body and pelvis-focused PET-MRI, which should be advantageous in the setting of recurrent prostate cancer.

SUMMARY

Hybrid PET-MRI with prostate cancer targeted radiopharmaceuticals and whole body with local multiparametric MRI can be complementary for detecting local and distant recurrence to guide treatment planning.

[Bone scan findings in a North African ethnic group and relation to PSA level and Gleason score of the biopsy]

OBJECTIVE

A number of large-scaled studies carried out in western countries have proven a positive relationship between serum prostate specific antigen (PSA) level and prevalence of positive bone scan findings, in newly diagnosed prostate cancer patients. The aim of our study is to verify that the tendency occurs as well in north-african population, as well as to establish a possible correlation between PSA level, bone scan result, and Gleason score.

MATERIAL AND METHODS

Records of 348 patients diagnosed to have prostatic adenocarcinoma were reviewed retrospectively for bone scan results, PSA levels, and Gleason score. Statistical analyses were performed using the Fisher exact test, by a statistical software (statistical package for the social sciences "SPSS", version 11.5.1, Chicago, IL) with differences at P<0,05 considered significant.

RESULTS

Based on positive bone scintigraphy 102 patients were proven to have bone metastases. None of these patients had a PSA level of less than 10 ng/ml. Six metastatic patients had PSA level between 11 and 20 ng/ml. 45 metastatic cases had serum PSA between 21 and 100. Concerning PSA level over 101 ng/ml, 51 men had positive bone scan.

CONCLUSION

Based on the PSA level, the likelihood of positive bone scan result can be postulated. According to PSA levels, staging investigations can be more selective for our patients. The risk of positive bone scan is so low that it is not required for patients with PSA level less than 10 ng/ml. On the other hand, on studying the correlation between Gleason score and PSA level or bone scan results, no statistically significant relationship was established.

[Prostate-specific antigen for treatment monitoring]

Today, most incident prostate cancer cases are diagnosed in early and thus potentially curable stages because of the determination of prostate-specific antigen (PSA). Treatment monitoring is another important aspect of the tumor marker PSA. In this article, contemporary recommendations for the use of PSA in treatment monitoring are discussed in the settings of active surveillance, radical prostatectomy and radiotherapy.

Imaging of prostate cancer

PURPOSE OF REVIEW

Appropriate imaging of prostate cancer is a crucial component of staging and therapy application. The purpose of this review is to highlight the most important developments in novel imaging modalities reported in the past year.

RECENT FINDINGS

Transrectal ultrasound is used to guide needle biopsy and brachytherapy. Improved results are obtained with color and power Doppler transrectal ultrasound with sonographic contrast agents. The role of elastography in prostate cancer remains to be elucidated. Magnetic resonance imaging is now widely used for staging before treatment and accumulating data indicate the utility of this technique with magnetic resonance spectroscopy in staging and follow-up. Positron-emission tomography alone or especially in combination with computed tomography imaging with the new radiotracers (11)C-choline, (18)F-fluorocholine, (11)C-acetate and (18)F-fluoride have shown promising results. Further investigations in larger clinical studies are necessary to establish the role of these imaging techniques in the management of patients with prostate cancer.

SUMMARY

This report provides a summary of novel types of imaging and indicates their promise in prostate cancer.