ESTRO 2023

Session Item

Urology

Session Code: 6018

Session Type: Poster (Digital)

Track: Clinical

5-year survival and toxicity results of SIB radiotherapy in (very) high-risk prostate cancer

, France

Presentation Number: PO-1465

Abstract

Abstract Title:

5-year survival and toxicity results of SIB radiotherapy in (very) high-risk prostate cancer

Authors:

Ingrid Masson¹, Catherine Guerin-Charbonnel², David Azria³, Pascal Pommier⁴, Nathalie Mesgouez-Nebout⁵, Philippe Giraud⁶, Didier Peiffert⁷, Bruno Chauvet⁸, Philippe Dudouet⁹, Naji Salem¹⁰, George Noel¹¹, Jonathan Khalifa¹², Igor Latorzeff¹³, Marc André Mahé¹⁴, Stéphane Supiot¹⁵

¹Institut de Cancérologie de l’Ouest René Gauducheau, Radiotherapy, Nantes , France; ²Institut de Cancérologie de l'Ouest René Gauducheau, Clinical Trial Sponsor Unit/Biometry, Nantes, France; ³Institut Régional du Cancer Montpellier (ICM), Fédération Universitaire d’Oncologie Radiothérapie (FOROM), Montpellier, France; ⁴Léon Bérard Center, Radiotherapy, Lyon, France; ⁵Institut de Cancérologie de l’Ouest Paul Papin, Radiotherapy, Angers, France; ⁶Georges Pompidou European Hospital, Radiotherapy, Paris, France; ⁷Lorraine Cancer Institute, Radiotherapy, Vandœuvre-lès-Nancy, France; ⁸Sainte Catherine Institute, Radiotherapy, Avignon, France; ⁹Pont de Chaume Clinic, Radiotherapy, Montauban, France; ¹⁰ Paoli-Calmettes Institute, Radiotherapy, Marseille, France; ¹¹Cancerology Institute of Strasbourg-Europe, Radiotherapy, Strasbourg, France; ¹²Institut Universitaire du Cancer de Toulouse-Oncopole (IUCT-Oncopole), Radiotherapy, Toulouse, France; ¹³Pasteur Clinic, Radiotherapy, Toulouse, France; ¹⁴François Baclesse Cancer Center, Radiotherapy, Caen, France; ¹⁵Institut de Cancérologie de l’Ouest René Gauducheau, Radiotherapy, Nantes, France

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Purpose or Objective

High-risk (HR) prostate cancer patients usually receive high-dose radiotherapy (RT) of 76-80 Gy to the prostate and 44-50 Gy to the pelvic lymph nodes using a sequential technique, but data on a simultaneous integrated boost (SIB) technique are lacking. We prospectively evaluated the long-term results of urinary (GU) and digestive (GI) toxicity and survival data of high-dose RT using a SIB technique in HR and very high-risk (VHR) prostate cancer.

Material and Methods

Patients were treated using an SIB technique in 34 fractions, at a dose of 54.4 Gy (1.6 Gy/fraction) to the pelvis and seminal vesicles and 74.8 Gy (2.2 Gy/fraction) to the prostate combined to 36 months androgen-depriving therapy in a prospective multicenter study “RCMI pelvis”, (NCT01325961). Urinary and digestive acute (≤ 3 months) and late toxicity (up to 5 years) were prospectively collected. Biochemical recurrence-free survival (BCRFS), local-relapse-free survival (LRFS), progression-free survival (PFS), metastasis-free survival (MFS) and overall survival (OS) were assessed using a Kaplan-Meier method.

Results

We recruited 114 patients (37 HR; 77 very high risk). After a median follow-up of 62 months, very few patients experienced acute (M0-M3) (G3-4 GU =3.7%; G3-4 GI=0.9%) or late (M6-M60) severe toxicity (G3-4 GU=5.5 %; G3-4 GI=2.8%). The occurrence of acute G2+ GU or GI toxicity was significantly related to the consequential late G2+ toxicity (p< 0.01 for both GU and GI). At 5 years, BCRFS, LRFS, PFS, MFS and OS were 86.0% [79.4%; 93.2%], 95.8% [91.8%;99.9%], 84.1% [77.2%;91.6%], 87.2% [80.9%;94.0%] and 88.2% [82.1%;94.7%] respectively.

Conclusion

SIB radiotherapy at a dose of 54.4 Gy (1.6 Gy/fraction) to the pelvic lymph nodes and seminal vesicles and 74.8 Gy (2.2 Gy/fraction) to the prostate is feasible, leading to satisfying tumor control and reasonable toxicity in HR and VHR prostate cancer.