Reirradiation of Prostate Cancer Local Failures After Previous Curative Radiation Therapy: Long-Term Outcome and Tolerance

Abstract

SummaryIn this retrospective study we evaluated the long-term results of 14 prostate cancer patients treated with salvage external beam radiation therapy (EBRT) for exclusive local failure after primary EBRT. Whole-gland reirradiation resulted in a high rate of severe radiationinduced side effects and poor long-term biochemical and local control. Alternative salvage reirradiation modalities should be explored for selected cases of local relapse in accurately designed prospective trials.Purpose: To evaluate the safety, feasibility, side-effect profile, and proof of concept of external beam radiation therapy (EBRT) with or without a brachytherapy (BT) boost for salvage of exclusive local failure after primary EBRT for prostate cancer. Methods and Materials: Fourteen patients with presumed exclusive local recurrence after primary EBRT with or without BT were considered eligible for reirradiation.The median normalized total dose in 2-Gy fractions (NTD 2Gy , a/b ratio Z 1.5 Gy) was 74 Gy (range, 66-98.4 Gy) at first irradiation. Median time between the first irradiation and the reirradiation was 6.1 years (range, 4.7-10.2 years). Results: Between 2003 and 2008 salvage treatment was delivered with a median NTD 2Gy of 85.1 Gy (range, 70-93.4) to the prostate with EBRT with (nZ10) or without (nZ4) BT. Androgen deprivation was given to 12 patients (median time of 12 months). No grade !3 toxicity was observed during and within 6 weeks after RT. After a median follow-up of 94 months (range, 48-172 months) after salvage RT, 5-year grade !3 genitourinary and gastrointestinal toxicity-free survival figures were 77.9% AE 11.3% and 57.1% AE 13.2%, respectively. Four patients presented with combined grade 4 genitourinary/gastrointestinal toxicity. The 5-year biochemical relapse-free, local relapse-free, distant metastasis-free, and cancer-specific survival rates were 35.7% AE 12.8%, 50.0% AE 13.4%, 85.7% AE 9.4%, and 100%, respectively. Conclusion: Salvage whole-gland reirradiation for patients with a suspicion of exclusive local recurrence after initial RT may be associated with a high rate of severe radiation-induced side effects and poor long-term biochemical and local control.

Early Toxicity of a Phase 2 Trial of Combined Salvage Radiation Therapy and Hormone Therapy in Oligometastatic Pelvic Node Relapses of Prostate Cancer (OLIGOPELVIS GETUG P07)

“…There were no increased urinary or digestive toxicity in these patients compared to those who had not previously been irradiated. These results are coherent with those from the other studies that considered pelvic reirradiation using stereotactic body radiotherapy [15]- [17] or even within the context of salvage WPRT directed by FCH-PET imaging [8]. Further study of the repair mechanisms in radiation injury to the pelvic tissues, and hence the feasibility of reirradiation, is highly recommended.…”

Reirradiation for isolated local recurrence of prostate cancer: Mono-institutional series of 64 patients treated with salvage stereotactic body radiotherapy (SBRT)

“…The efficacy of salvage reirradiation for locally recurrent PCa has been evaluated by several investigations. [14][15][16][17][18][19][22][23][24][25][26][28][29][30][31][32][33][34] The first report on re-EBRT by Vavassori et al 15 including six cases treated by CyberKnife, showed the feasibility of reirradiation with an acceptable rate of acute and early chronic toxicity (median follow-up was 11.3 months). These preliminary findings were then confirmed by the successive series.…”

“…14,[16][17][18][19][28][29][30][31][32][33][34] All but one report concluded that salvage re-EBRT is safe. [14][15][16][17][18][19][20][21][23][24][25][26][27] Zilli et al 22 published the data of 14 patients treated with whole prostate reirradiation, with the median follow-up of 94 months, showing low acute but very high late GU and GI toxicity rates (29% of patients experienced combined Grade 4 GU/GI injury). Contrarily to the Zilli's series, we observed only 1 Grade 3 GU event among 20 males with follow-up >36 months.…”

“…7,12 As far as reirradiation is concerned, the vast majority of patient series were treated with brachytherapy (BRT). In the last years, along with the improvement in radiotherapy (RT) planning and delivery technology, several reports on salvage EBRT have been published [14][15][16][17][18][19][20][21][22][23][24][25][26][27] (Table 1).…”

Re: Stereotactic Body Re-irradiation Therapy for Locally Recurrent Prostate Cancer After External-beam Radiation Therapy: Initial Report

“…Using advanced imaging (recurrence identified by magnetic resonance, staging based on [ 18 F]-fluorocholine positron emission tomography), highly selective radiotherapy modalities (stereotactic body radiotherapy and image-guided intensity-modulated radiotherapy), and extreme hypofractionation (doses > 6 Gy/fraction), Janoray et al showed that reirradiation is safe and may offer a medium-term cure in a good proportion of patients. By contrast, a report on reirradiation using conventional techniques and conventional fractionation (2 Gy/fraction) to the full radiation dose showed unacceptable toxicity and unsatisfactory tumor control [4]. These small but important series add new data to the current view of radiotherapy issues for prostate cancer: high fractionation sensitivity is an intrinsic property of primary prostate cancer, and there is now growing evidence that the same approach may work for radiationrecurrent cancer.…”