The Dedicated Imaging Post-Prostatectomy for Enhanced Radiotherapy outcomes (DIPPER) trial protocol: a multicentre, randomised trial of salvage radiotherapy versus surveillance for low-risk biochemical recurrence after radical prostatectomy

Matthew J Roberts; Ciara Conduit; Ian D Davis; Rachel M Effeney; Scott Williams; Jarad M Martin; Michael S Hofman; George Hruby; Renu Eapen; Chris Gianacas; Nathan Papa; Richard De Abreu Lourenço; Haryana M Dhillon; Ray Allen; Antoinette Fontela; Baldeep Kaur; Louise Emmett; Australian and New Zealand Urogenital and Prostate Cancer Trials Group (ANZUP)

doi:10.1111/bju.16158

The Dedicated Imaging Post-Prostatectomy for Enhanced Radiotherapy outcomes (DIPPER) trial protocol: a multicentre, randomised trial of salvage radiotherapy versus surveillance for low-risk biochemical recurrence after radical prostatectomy

BJU Int. 2024 Feb:133 Suppl 3:39-47. doi: 10.1111/bju.16158. Epub 2023 Sep 14.

Authors

Matthew J Roberts^{1

2

3

4}, Ciara Conduit^{1

5

6

7}, Ian D Davis^{1

8

9}, Rachel M Effeney^{1

2

3}, Scott Williams^{1

7

10}, Jarad M Martin^{1

11

12}, Michael S Hofman^{7

13}, George Hruby^{1

14

15

16}, Renu Eapen^{1

7

17

18}, Chris Gianacas^{19

20}, Nathan Papa^{1

21}, Richard De Abreu Lourenço^{1

22}, Haryana M Dhillon^{1

11}, Ray Allen¹, Antoinette Fontela¹, Baldeep Kaur²⁰, Louise Emmett^{1

23

24

25}; Australian and New Zealand Urogenital and Prostate Cancer Trials Group (ANZUP)

Affiliations

¹ The Australian and New Zealand Urogenital and Prostate Cancer Trials Group (ANZUP), Camperdown, NSW, Australia.
² Royal Brisbane and Women's Hospital, Herston, Qld, Australia.
³ Redcliffe Hospital, Redcliffe, Qld, Australia.
⁴ Faculty of Medicine, Centre for Clinical Research, The University of Queensland, Brisbane, Qld, Australia.
⁵ Walter and Eliza Hall Institute of Medical Research, Melbourne, Vic., Australia.
⁶ Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Vic., Australia.
⁷ Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Vic., Australia.
⁸ Department of Medical Oncology, Eastern Health, Box Hill, Vic., Australia.
⁹ Monash University Eastern Health Clinical School, Box Hill, Clayton, Vic., Australia.
¹⁰ Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Vic., Australia.
¹¹ Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, NSW, Australia.
¹² University of Newcastle, Newcastle, NSW, Australia.
¹³ Molecular Imaging and Therapeutic Nuclear Medicine, Cancer Imaging, Prostate Cancer Theranostics and Imaging Centre of Excellence (ProsTIC), Peter MacCallum Centre, Melbourne, Vic., Australia.
¹⁴ University of Sydney, Sydney, NSW, Australia.
¹⁵ St Vincent's Clinic, Sydney, NSW, Australia.
¹⁶ Royal North Shore Hospital, Sydney, NSW, Australia.
¹⁷ Olivia Newton-John Cancer Research Institute, Heidelberg, Vic., Australia.
¹⁸ Austin Hospital, Heidelberg, Vic., Australia.
¹⁹ School of Population Health, UNSW Sydney, Sydney, NSW, Australia.
²⁰ The George Institute for Global Health, Newtown, NSW, Australia.
²¹ School of Public Health and Preventive Medicine, Monash University, Melbourne, Vic., Australia.
²² Centre for Health Economics Research and Evaluation, University of Technology Sydney, Sydney, NSW, Australia.
²³ Department of Theranostics and Nuclear Medicine, St Vincent's Hospital, Sydney, NSW, Australia.
²⁴ Garvan Institute of Medical Research, Sydney, NSW, Australia.
²⁵ University of NSW, Sydney, NSW, Australia.

PMID: 37604702
DOI: 10.1111/bju.16158

Abstract

Background: Salvage radiation therapy (SRT) and surveillance for low-risk prostate-specific antigen (PSA) recurrence have competing risks and benefits. The efficacy of early SRT to the prostate bed with or without pelvic lymph nodes compared to surveillance in patients with PSA recurrence after radical prostatectomy and no identifiable recurrent disease evident on prostate specific membrane antigen-positron emission tomography/computer tomography (PSMA-PET/CT) is unknown.

Study design: The Dedicated Imaging Post-Prostatectomy for Enhanced Radiotherapy outcomes (DIPPER) is an open-label, multicentre, randomised Phase II trial.

Endpoints: The primary endpoint is 3-year event-free survival, with events comprising one of PSA recurrence (PSA ≥0.2 ng/mL higher than baseline), radiological evidence of metastatic disease, or initiation of systemic or other salvage treatments. Secondary endpoints include patient-reported outcomes, treatment patterns, participant perceptions, and cost-effectiveness.

Eligibility criteria: Eligible participants have PSA recurrence of prostate cancer after radical prostatectomy, defined by serum PSA level of 0.2-0.5 ng/mL, deemed low risk according to modified European Association of Urology biochemical recurrence risk criteria (International Society for Urological Pathology Grade Group ≤2, PSA doubling time >12 months), with no definite/probable recurrent prostate cancer on PSMA-PET/CT.

Patients and methods: A total of 100 participants will be recruited from five Australian centres and randomised 1:1 to SRT or surveillance. Participants will undergo 6-monthly clinical evaluation for up to 36 months. Androgen-deprivation therapy is not permissible. Enrolment commenced May 2023.

Trial registration: This trial has been registered with the Australian New Zealand Clinical Trials Registry (ACTRN: ACTRN12622001478707).

Keywords: clinical trial protocol; patient-reported outcome measures; positron emission tomography-computed tomography; prostate neoplasm; prostate-specific antigen; radical prostatectomy; radiotherapy.

Publication types

Clinical Trial Protocol

MeSH terms

Androgen Antagonists / therapeutic use
Australia / epidemiology
Clinical Trials, Phase II as Topic
Gallium Radioisotopes / therapeutic use
Humans
Male
Multicenter Studies as Topic
Neoplasm Recurrence, Local / pathology
Positron Emission Tomography Computed Tomography / methods
Prostate / pathology
Prostate-Specific Antigen*
Prostatectomy / methods
Prostatic Neoplasms* / diagnostic imaging
Prostatic Neoplasms* / radiotherapy
Prostatic Neoplasms* / surgery
Randomized Controlled Trials as Topic
Salvage Therapy / methods

Substances

Prostate-Specific Antigen
Androgen Antagonists
Gallium Radioisotopes

Abstract

Publication types

MeSH terms

Substances

Grants and funding