Bowel and urinary quality of life after whole-pelvic versus prostate-only volumetric-modulated arc therapy for localized prostate cancer

Elective Nodal Irradiation for Oligorecurrent Nodal Prostate Cancer: Interobserver Variability in the PEACE V-STORM Randomized Phase 2 Trial

Purpose

Consistency in delineation of pelvic lymph node regions for prostate cancer elective nodal radiation therapy is still challenging despite current guidelines. The aim of this study was to evaluate the interobserver variability in elective lymph node delineation in the PEACE V - STORM randomized phase 2 trial for oligorecurrent nodal prostate cancer.

Methods and Materials

Twenty-three centers were asked to delineate the elective pelvic nodal clinical target volume (CTV) of a postoperative oligorecurrent nodal prostate cancer benchmark case using a modified Radiation Therapy Oncology Group (RTOG) 2009 template (upper limit at the L4/L5 interspace). Overall, intersection and overflow volumes, Dice coefficient, Hausdorff distance, and count maps merged with computed tomography images were analyzed.

Results

The mean volume including the 23 nodal CTVs was 430.4 ± 64.1 cm3, larger than the modified RTOG 2009 CTV reference volume (386.1 cm3). The intersection common volume between the modified reference RTOG 2009 and the 23 nodal CTVs was estimated at 83.9%, whereas the overflow volume was 23.4%, mainly located at the level of the presacral and the upper limit of the L4/L5 interspace. The mean Dice coefficient was 0.79 ± 0.02, whereas the mean Hausdorff distance was 27 ± 4.4 mm.

Conclusions

In salvage radiation therapy treatment of oligorecurrent nodal prostate cancer, variations in elective lymph node volume delineation were mainly observed in the presacral and common iliac areas. Routine implementation and diffusion of available contouring guidelines together with a constant evaluation and evidence-based updating are expected to further decrease the existing variability in pelvic node contouring.

Patient-reported outcomes after curative treatment for prostate cancer with prostatectomy, primary radiotherapy or salvage radiotherapy

BACKGROUND

Trials reporting adverse health outcomes (AHOs) in terms of patient-reported outcome measures (PROMs) after contemporary curative treatment of prostate cancer (PC) are hampered by study heterogeneity and lack of new treatment techniques. Particularly, the evidence regarding toxicities after radiotherapy (RT) with the volumetric arc therapy (VMAT) technique is limited, and comparisons between men treated with surgery, primary radiotherapy (PRT) and salvage radiotherapy (SRT) are lacking. The aim of the study was to evaluate change in PROMs 3 months after treatment with robotic-assisted laparoscopic prostatectomy (RALP), PRT and SRT administered with VMAT.

MATERIAL AND METHODS

A prospective cohort study of men with PC who received curative treatment at the University Hospital of North Norway between 2012 and 2017 for RALP and between 2016 and 2021 for radiotherapy was conducted. A cohort of 787 men were included; 406 men treated with RALP, 265 received PRT and 116 received SRT. Patients completed the validated PROM instrument EPIC-26 before (pre-treatment) and 3 months after treatment. EPIC-26 domain summary scores (DSSs) were analysed, and changes from pre-treatment to 3 months reported. Changes were deemed clinically relevant if exceeding validated minimally clinically important differences (MCIDs).

RESULTS

Men treated with RALP reported clinically relevant declining urinary incontinence DSS (-41.7 (SD 30.7)) and sexual DSS (-46.1 (SD 30.2)). Men who received PRT reported worsened urinary irritative DSS (-5.2 (SD 19.6)), bowel DSS (-8.2 (SD 15.1)) and hormonal DSS (-9.6 (SD 18.2)). Men treated with SRT experienced worsened urinary incontinence DSS (-7.3 (SD 18.2)), urinary irritative DSS (-7.5 (SD 14.0)), bowel DSS (-12.5 (SD 16.1)), sexual DSS (-14.9 (SD 18.9)) and hormonal DSS (-23.8 (SD 20.9)).

CONCLUSION

AHOs 3 months after contemporary curative treatment for PC varied according to treatment modality and worsened in all treatment groups, although most in SRT.

Efficacy and Toxicity of Whole Pelvic Radiotherapy Versus Prostate-Only Radiotherapy in Localized Prostate Cancer: A Systematic Review and Meta-Analysis

Background

There is little level 1 evidence regarding the relative efficacy and toxicity of whole pelvic radiotherapy (WPRT) compared with prostate-only radiotherapy (PORT) for localized prostate cancer.

Methods

We used Cochrane, PubMed, Embase, Medline databases, and ClinicalTrials.gov to systematically search for all relevant clinical studies. The data on efficacy and toxicity were extracted for quality assessment and meta-analysis to quantify the effect of WPRT on biochemical failure-free survival (BFFS), progression-free survival (PFS), distant metastasis-free survival (DMFS), overall survival (OS), gastrointestinal (GI) toxicity, and genitourinary (GU) toxicity compared with PORT. The review is registered on PROSPERO, number: CRD42021254752.

Results

The results revealed that compared with PORT, WPRT significantly improved 5-year BFFS and PFS, and it was irrelevant to whether the patients had undergone radical prostatectomy (RP). In addition, for the patients who did not receive RP, the 5-year DMFS of WPRT was better than that of PORT. However, WPRT significantly increased not only the grade 2 or worse (G2+) acute GI toxicity of non-RP studies and RP studies, but also the G2+ late GI toxicity of non-RP studies. Subgroup analysis of non-RP studies found that, when the pelvic radiation dose was >49 Gy (equivalent-doses-in-2-Gy-fractions, EQD-2), WPRT was more beneficial to PFS than PORT, but significantly increased the risk of G2+ acute and late GU toxicity.

Conclusions

Meta-analysis demonstrates that WPRT can significantly improve BFFS and PFS for localized prostate cancer than PORT, but the increased risk of G2+ acute and late GI toxicity must be considered.

Systematic Review Registration

PROSPERO CRD42021254752.

Elective nodal radiotherapy in prostate cancer

In patients with prostate cancer who have a high risk of pelvic nodal disease, the use of elective whole pelvis radiotherapy is still controversial. Two large, randomised, controlled trials (RTOG 9413 and GETUG-01) did not show a benefit of elective whole pelvis radiotherapy over prostate-only radiotherapy. In 2020, the POP-RT trial established the role of elective whole pelvis radiotherapy in patients who have more than a 35% risk of lymph node invasion (known as the Roach formula). POP-RT stressed the importance of patient selection. In patients with cN1 (clinically node positive) disease or pN1 (pathologically node positive) disease, the addition of whole pelvis radiotherapy to androgen deprivation therapy significantly improved survival compared with androgen deprivation therapy alone, as shown in large, retrospective studies. This patient population might increase in the future because use of the more sensitive prostate-specific membrane antigen PET-CT will become the standard staging procedure. Additionally, the SPORTT trial suggested a benefit of whole pelvis radiotherapy in biochemical recurrence-free survival in the salvage setting. A correct definition of the upper field border, which should include the bifurcation of the abdominal aorta, is key in the use of pelvic radiotherapy. As a result of using modern radiotherapy technology, severe late urinary and intestinal toxic effects are rare and do not seem to increase compared with prostate-only radiotherapy.