Radiotherapy for pelvic nodal recurrences after radical prostatectomy: patient selection in clinical practice

Cedric Panje,Kathrin Brouwer,Paul Martin Putora,Silvia Gomez,Kaouthar Khanfir,Fernanda Herrera,Helena I Garcia Schüler,Alexandros Papachristofilou,Daniel Zwahlen,Gianfranco Pesce,Winfried Arnold,Hansjörg Vees,Christiane Reuter,Thomas Zilli,Alan Dal Pra

doi:10.1186/s13014-019-1383-0

Abstract

AimThere is no general consensus on the optimal treatment for prostate cancer (PC) patients with intrapelvic nodal oligorecurrences after radical prostatectomy. Besides androgen deprivation therapy (ADT) as standard of care, both elective nodal radiotherapy (ENRT) and stereotactic body radiotherapy (SBRT) as well as salvage lymph node dissection (sLND) are common treatment options. The aim of our study was to assess decision making and practice patterns for salvage radiotherapy (RT) in this setting.MethodsTreatment recommendations from 14 Swiss radiation oncology centers were collected and converted into decision trees. An iterative process using the objective consensus methodology was applied to assess differences and consensus.ResultsPSMA PET/CT was recommended by 93% of the centers as restaging modality. For unfit patients defined by age, comorbidities or low performance status, androgen deprivation therapy (ADT) alone was recommended by more than 70%. For fit patients with unfavorable tumor characteristics such as short prostate-specific antigen (PSA) doubling time or initial high-risk disease, the majority of the centers (57–71%) recommended ENRT + ADT for 1–4 lesions. For fit patients with favorable tumor characteristics, there were low levels of consensus and a wide variety of recommendations. For 1–4 nodal lesions, focal SBRT was offered by 64% of the centers, most commonly as a 5-fraction course.ConclusionsAs an alternative to ADT, ENRT or SBRT for pelvic nodal oligorecurrences of PC are commonly offered to selected patients, with large treatment variations between centers. The exact number of lymph nodes had a major impact on treatment selection.

Highlights

Regional nodal recurrence of prostate cancer (PC) limited to the pelvis after curative local therapies such as radical prostatectomy (RP) or primary radiotherapy (RT) is an emerging clinical scenario
Decision criteria from all centers were collected and merged with the agreement of all participants into the criteria “patient fitness” and “favorable vs. unfavorable tumor characteristics” in order to facilitate the comparability of decision algorithms [12]: Patient fitness was defined by the majority of centers by age (64%) and performance status (57%) as well as by comorbidities (64%)
There was a high level of consensus for the use of androgen deprivation therapy (ADT) without RT in case of six or more nodal recurrences in fit patient or in two or more nodal recurrences in unfit patients

Summary

Introduction

Regional nodal recurrence of prostate cancer (PC) limited to the pelvis (pelvic oligorecurrences) after curative local therapies such as radical prostatectomy (RP) or primary radiotherapy (RT) is an emerging clinical scenario. In part, this may be explained by the broad implementation of novel metabolic imaging strategies such as choline and prostate specific membrane antigen (PSMA) PET-CT in Current PC guidelines such as the European Association of Urology (EAU) and European Society of Radiation. Based on similar analyses among radiation oncology centers on radiotherapy for primary PC and for macroscopic local recurrences [9, 10], the aim of this study was to assess current patterns of practice for pelvic nodal oligorecurrences of PC after RP among centers within a similar environment. The Swiss centers that were analyzed are all within the same environment characterized by universal healthcare coverage, modern equipment, uncomplicated reimbursement and no significant logistical or transport obstacles for patients

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