[Prostate cancer]

[Irreversible electroporation (IRE) : A minimally invasive therapeutic option in prostate cancer]

CLINICAL PROBLEM

Prostate cancer is one of the most common malignant diseases in older men. As such, screening and early detection are of crucial importance.

STANDARD TREATMENT

The standard management of prostate cancer includes radical prostatectomy, radiation therapy, or hormonal therapy. These standard therapies yield excellent oncologic results, but also produce significant side effects. In cases of low-risk prostate cancer, these therapies might result in over-treatment; for this reason, active surveillance has been introduced. However, acceptance of this strategy varies between patients.

TREATMENT INNOVATIONS

Irreversible electroporation is a novel non-thermal ablation technique for soft tissues. The ablation mechanism of irreversible electroporation has some theoretical advantages in the treatment of prostate cancer. It allows image-guided focal treatment of malignant prostate tissue and a potential sparing of adjacent structures, thereby theoretically resulting in a marked reduction in treatment-related side effects compared with standard management.

PRACTICAL RECOMMENDATIONS

Although irreversible electroporation is a promising ablation technique, it should only be used in the context of clinical trials to treat prostate cancer due to the current lack of solid evidence for this new technology.

[Diagnostic significance of multiparametric MRI combined with US-fusion guided biopsy of the prostate in patients with increased PSA levels and negative standard biopsy results to detect significant prostate cancer - Correlation with the Gleason score. Korrelation mit dem Gleason Score]

AIMS

To increase diagnostic precision and to reduce overtreatment of low-risk malignant disease, multiparametric MRI (mpMRI) combined with ultrasound (US) fusion guided biopsy of the prostate were performed.

METHODS

In 99 male patients with increased PSA plasma levels and previous negative standard biopsy procedures, mpMRI was carried out followed by US fusion guided perineal biopsy. PI-RADS-Data (PS) of mpMRI and histopathological Gleason score (GS) were categorized and statistically compared.

RESULTS

Lesions in 72/99 (73 %) of patients were determined to be suspect of malignancy, based on a PS 4 or 5. In 33/99 (33 %) of patients, malignancy could not be confirmed by histopathology. With regard to the remaining 66 patients with previous negative biopsy results, 42 (64 %) were diagnosed with a low-grade carcinoma (GS 6, 7a) and 24 (36 %) with a high-grade carcinoma (GS ≥ 7b). The proportion of corresponding results in mpMRI (PS 4-5) when a high-grade carcinoma had been detected, was 21/24 (88 %), which related to a sensitivity of 88 % and a negative predictive value (NPV) of 85 % (p = 0,002). In addition, 35 of 42 patients (83%), graded PS 4-5 in mpMRI, were diagnosed with low-grade carcinoma-positive (p < 0,001). Sensitivity to differentiation between low- and high-grade carcinomas (GS ≤ 7a vs. ≥ 7b) by means of PS was 88 % with a NPV of 70 % (p = 0,74).

CONCLUSION

Our results suggest that mpMRI combined with US-fusion guided biopsy is able to detect considerably higher rates of clinically relevant prostate malignancies compared to conventional diagnostic procedures. However, no statistical significance could be shown regarding the differentiation between high- and low-grade carcinomas. It is hoped that the hybrid methods PSMA-PET/CT or PSMA-PET/MRI will lead to the next optimization step in the differentiation between high- and low-grade carcinomas which so far has been unsatisfactory.