ESTRO 2022

Session Item

Sunday

May 08

16:55 - 17:55

Room D1

Urology

Co-Chair: Nejla Fourati, Tunisia;

Chair: , Germany

Session Type: Proffered Papers

Track: Clinical

Journey:

17:15 - 17:25

Radiotherapy guided by functional imaging for macroscopic local recurrence following prostatectomy

Nicolas Benziane Ouaritini, France

Presentation Number: OC-0607

Abstract

Abstract Title:

Radiotherapy guided by functional imaging for macroscopic local recurrence following prostatectomy

Authors:

Nicolas Benziane¹, Paul Sargos¹, Thomas Zilli², Antoine Giraud³, Gianluca Ingrosso⁴, Marco Di Staso⁵, Fabio Trippa⁶, Emmanuel Meyer⁷, Giulio Francolini⁸, Ulrike Schick⁹, Jean Marc Cosset¹⁰, Etienne Martin¹¹, Victoria Ferrari¹², Vérane Achard¹³, Nicolas Giraud¹, Corentin Pasquier¹⁴, Nicolas Magné¹⁵, David Pasquier¹⁶, Stéphane Supiot¹⁷, Igor Latorzeff¹⁸, Khemara Gnep¹⁹, Pascal Pommier²⁰, Tanguy Perennec¹⁷, Hind Zaine¹⁶

¹Institut Bergonié, Radiation Oncology, Bordeaux, France; ²CHU Genève, Radiation Oncology, Geneve, Switzerland; ³Institut Bergonié, Bio-statistique, Bordeaux, France; ⁴University Of Perugia, Radiation Oncology, Perugia, Italy; ⁵Nuovo San Salvatore, Radiation Oncology, l'Aquila, Italy; ⁶Santa Maria Hospital, Radiation Oncology, Terni, Italy; ⁷Centre Francois Beclesse, Radiation Oncology, Caen, France; ⁸University of Florence, Radiation Oncology, Florence, Italy; ⁹University Hospital Cavale Blanche, Radiation Oncology, Brest, France; ¹⁰Groupe Amethyst, Radiation Oncology, Lagarenne Colombes, France; ¹¹Centre François Leclerc, Radiation Oncology, Dijon, France; ¹²Centre Antoine Lacassagne, Medical Oncology, Nice, France; ¹³CHU Genève, Radiation Oncology, Gevève, Switzerland; ¹⁴Oncopole Toulouse, Radiation Oncology, Toulouse, France; ¹⁵Institut de Cancérologie de la Loire, Radiation Oncology, Saint Etienne, France; ¹⁶Centre Oscar Lambret, Radiation Oncology, Lille, France; ¹⁷Centre de Cancérologie de l'Ouest, Radiation Oncology, Nantes, France; ¹⁸Clinique Pasteur, Radiation Oncology, Toulouse, France; ¹⁹Centre Eugène Marquis, Radiation oncology, Rennes, France; ²⁰Centre Léon Bérard, Radiation oncology, Lyon, France

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Purpose or Objective

For prostate cancer (Pca), salvage radiotherapy (sRT) with or without androgen deprivation therapy (ADT) is currently the only curative treatment option in case of post-radical prostatectomy (RP) biochemical relapse (BR). Functional imaging techniques have shown that macroscopic recurrence (MR) in the prostate bed (PB) are frequent. In this study, we aimed to assess efficacy and safety of sRT in patients with MR inside the PB proven by functional imaging.

Material and Methods

A multicenter retrospective study (SPIDER 01) was conducted in 16 European centers. Patients were included if they displayed BR after RP for Pca, with MR only in the PB proven by functional imaging. All patients had to be eligible for sRT. The overall population was divided along 4 groups according to the delivered treatment: dose escalation on MR (A), dose escalation on PB (B), double dose escalation MR+PB (C), no dose escalation (D). The primary endpoint was progression-free survival (PFS). Secondary outcomes included the metastasis-free survival (MFS), biochemical PFS (bPFS) and overall survival (OS). Grade ≥2 genito-urinary (GU) and gastro-intestinal (GI) acute and late toxicities were collected.

Results

Between January 2000 and December 2019, 363 patients with isolated MR after RP for Pca were treated by sRT. The median pre-sRT PSA level was 0.63ng/mL (range, 0.2-23.6). At the time of BR, 266 (73%) patients presented MR in the PB proven by magnetic resonance imaging, and 110 (30%) by positron emission tomography. The median follow-up was 53.6 months (range, 47.52; 58.32). The 5-year PFS and MFS were 70% (95%CI [63.8-75.4]) and 83.7% (95%CI [78.4-87.8]), respectively. Grade ≥2 GU and GI late toxicities were found in 43 (12%) and 11 (3%) patients, respectively. A 5-year PFS benefit was highlighted for groups A, B and C (313 patients) when the MR dose was ≥72Gy: 72,8% (95%CI 64.6-79.4) versus 60.3% (95%CI 48,4-70,3), p=0.03.

Conclusion

SPIDER 01, a modern series integrating salvage radiotherapy guided by functional imaging data, we confirmed that sRT is effective in the event of MR inside the PB, with an acceptable toxicity profile. In addition, with the help of functional imaging, we found that dose escalated ≥ 72 Gy on the MR had a significant impact on PFS. Prospective data should further investigate the correlation between MR-targeted dose escalation and PFS.