Imaging for Surgery, Focal Therapy & Radiation Treatment Planning
Satoru Takahashi1

1Japan

Synopsis

Basis, characteristics and indication of potential definitive therapy for the prostate cancer; including radical prostatectomy, radiotherapy, local ablation therapy, will be demonstrated for better understanding of the appropriate management of newly diagnosed prostate cancer.

Surgical and radiological anatomy of crucial structures for preventing complications of radical prostatectomy, as well as tips, trick and pitfalls for visualizing and evaluating vital structures will be discussed.

TARGET AUDIENCE

Imaging has been applied for lesion detection (including screening), characterization (or differential diagnosis), staging (including survey of metastases), treatment simulation, and therapy evaluation. As the roles of imaging in lesion detection and therapy evaluation will be discussed by other speakers, the main target audience for this talk will be body radiologists and physicists, who are involved in the management of newly diagnosed prostate cancer to make appropriate treatment decisions for patients.

BACKGROUNDS

The prostate cancer has a wide range of treatment options; including “NO” immediate treatment (active surveillance or watchful waiting), surgery (open, laparoscopic, robotic), radiotherapy (brachytherapy, intensity modulation radiotherapy, proton beam), local ablation therapy (cryosurgery, laser, radiofrequency ablation), hormonal therapy, or chemotherapy, as well as combinations of some of these treatments. As patient selection for appropriate treatments remains a challenge, many clinical guidelines apply risk group classification based on the grouping of patients with a similar risk of biochemical recurrence after radical prostatectomy or external beam radiotherapy. In general, parameters used for risk classification include initial prostate specific antigen (PSA), clinical T-stage, and Biopsy Gleason score(1). T2-weighted MR imaging is the most useful method for the evaluation of T-stage, while the use of 3T or diffusion-weighted imaging or dynamic contrast enhanced study can improve sensitivity for extra-prostatic extension or seminal vesicle invasion. Thus, PSA measurement and accurate assessments of cancer aggressiveness (i.e. Gleason score) are, therefore, needed for comprehensive risk stratification. It is, however, well known that there are discrepancies between the Gleason score evaluated with systematic biopsy and surgery. MRI-targeted biopsies based on Pi-RADS scoring substantially improve the detection of clinically significant cancer of Gleason 7 or more. In addition, as there are several features in functional imaging, in cases of clinically significant cancer in comparison to clinically insignificant cancers, it is expected that multi-parametric MRI could provide global risk assessment of the prostate cancer. When a patient is assessed as a candidate for definitive therapy after risk stratification, treatment strategy will be selected based on risk classification, length of expected survival, as well as socioeconomical environment.

LEARNING OBJECTIVES

  • Basis, characteristics and indication of potential definitive therapy for the prostate cancer
  1. Radical prostatectomy with either open, laparoscopic, or robotic-assistedØ Radiotherapy with brachytherapy, intensity modulation radiotherapy (IMRT), or proton beam therapy
  2. Local ablation therapy with cryosurgery, laser, radiofrequency ablation, high-intensity focus ultrasound (HIFU), or hemi-gland brachytherapy
  3. Pros and cons of each definitive therapy
  4. Roles of imaging in deciding treatment strategy
  • Surgical and radiological anatomy of crucial structures for preventing complications of radical prostatectomy
  1. Neurovascular bundle
  2. Bladder neck
  3. Apex and sphincters
  • Tips, Trick and Pitfalls for visualizing and evaluating vital structures
  1. 1.5T vs. 3.0T
  2. With or without endorectal coil
  3. Multi-parametric MRI
  4. 2D- or 3D- turbo SE T2-weighted imaging
  5. MRI-derived parameters such as the tumor volume or the contact length of the tumor with the capsuleØ
  6. Limitation of imaging for the evaluation of nodal metastasis

Acknowledgements

No acknowledgement found.

References

  1. Mottet N., Bellmunt J., Briers E., Bolla M., Bourke L., Cornford P., De Santis M., Henry A., Joniau S., Lam T., Mason M.D., Van den Poel H., Van den Kwast T.H., Rouvière O., Wiegel T.; members of the EAU – ESTRO – ESUR –SIOG Prostate Cancer Guidelines Panel. EAU – ESTRO – ESUR – SIOG Guidelines on Prostate Cancer. Edn. presented at the EAU Annual Congress Copenhagen 2018. 978-94-92671-02-8. Publisher: EAU Guidelines Office. Place published: Arnhem, The Netherlands.
  2. National Comprehensive Cancer Network. Prostate cancer (Version 1.2019). https://www.nccn.org/professionals/physician_gls/pdf/prostate.pdf. Accessed, March 14, 2019.
  3. de Rooij M, et al: Accuracy of Magnetic Resonance Imaging for Local Staging of Prostate Cancer: A Diagnostic Meta-analysis. Eur Urol, 70: 233-245, 2016.
Proc. Intl. Soc. Mag. Reson. Med. 27 (2019)