Mapping of Recurrence Sites Following Adjuvant or Salvage Radiotherapy for Prostate Cancer Patients

Ana Gonzalez-Moya; Stéphane Supiot; Valérie Seegers; Thibaut Lizée; Florence Legouté; Tanguy Perennec; Gilles Calais

doi:10.3389/fonc.2021.787347

Mapping of Recurrence Sites Following Adjuvant or Salvage Radiotherapy for Prostate Cancer Patients

Front Oncol. 2022 Jan 5:11:787347. doi: 10.3389/fonc.2021.787347. eCollection 2021.

Authors

Ana Gonzalez-Moya¹, Stéphane Supiot², Valérie Seegers³, Thibaut Lizée⁴, Florence Legouté⁵, Tanguy Perennec², Gilles Calais⁶

Affiliations

¹ Department of Radiation Oncology, Institut de Cancérologie de l'Ouest, Angers, France.
² Department of Radiation Oncology, Institut de Cancérologie de l'Ouest, Nantes, France.
³ Department of Medical Biostatistics, Institut de Cancérologie de l'Ouest, Angers, France.
⁴ Department of Radiation Oncology, Jean Bernard Center, Inter-Regional Institute of Oncology, Le Mans, France.
⁵ Department of Radiation Oncology, Hospital Center, La Roche sur Yon, France.
⁶ Department of Radiation Oncology, University Hospital Center, Tours, France.

Abstract

Introduction: Although salvage and adjuvant radiotherapy (RT) are effective in prostate cancer (PC) patients, 30%-40% of men will have disease progression. The objective was to describe the pattern of recurrence in PC patients with biochemical failure (BF) following postoperative RT.

Methods: We retrospectively analyzed 935 PC patients treated from 2009 to 2019 with adjuvant or salvage RT at the Institut de Cancérologie de l'Ouest. Of these, 205 (22%) developed BF of whom 166 underwent imaging. Patients with identified radiologic failure prior any specific treatment were included to determine the site of relapse categorized as local (L)-only, locoregional (LR), or metastatic (M) recurrence. Main disease characteristics and RT fields were examined in relation to sites of recurrence.

Results: One hundred forty-one patients were identified with 244 sites of failure on imaging. Of these, 108 patients had received RT to the PB alone and 33 RT to the PB and pelvic lymph nodes (PB+PLN). Androgen-deprivation therapy was used concomitantly in 50 patients (35%). The median PSA at imaging was 1.6 ng/ml (range, 0-86.7). In all, 74 patients (52%) had M disease (44% in the PB group and 79% in the PB+PLN group), 61 (43%) had LR failure (52% in the PB alone group and 15% in the PB+PLN group), and six (4%) had L-only failure, at a median of 26.7 months (range, 5-110.3) from RT. Metastases were in extra-pelvic LN (37 (15%)), bones (66 (27%)), and visceral organs (eight (3%)). Fifty-three (48%) of the pelvic LN failures in the PB group would have been encompassed by standard PLN RT volume.

Conclusion: We found that most patients evaluated for BF after postoperative RT recurred outside the RT field. Isolated pelvic nodal failure was rare in those receiving RT to the PB+PLN but accounted for half of failures in those receiving PB alone RT. Imaging directed salvage treatment could be helpful to personalize radiation therapy plan.

Keywords: adjuvant/salvage radiotherapy; pattern of recurrence; pelvic radiotherapy; prostate bed radiotherapy; prostate cancer.