Comparing bowel and urinary domains of patient-reported quality of life at the end of and 3 months post radiotherapy between intensity-modulated radiotherapy and proton beam therapy for clinically localized prostate cancer

Choosing the right questions - A systematic review of patient reported outcome measures used in radiotherapy and proton beam therapy

The implementation of PROMs into clinical practice has been shown to improve quality of care. This systematic review aims to identify which PROMs are suitable for implementation within routine clinical practice in a radiotherapy or PBT service.The bibliographic databases MEDLINE, EMBASE and EMCARE were searched. Articles published between 1st January 2008 to 1st June 2023, that reported PROMs being utilised as an outcome measure were included. Inclusion criteria also included being written in English, involving human patients, aged 16 and above, receiving external beam radiotherapy or PBT for six defined tumour sites. PROMs identified within the included articles were subjected to quality assessment using the COSMIN reporting guidelines. Results are reported as per PRISMA guidelines. A total of 268 studies were identified in the search, of which 52 fulfilled the inclusion criteria. The use of 39 different PROMs was reported. The PROMs identified were mostly tumour or site-specific quality of life (n = 23) measures but also included generic cancer (n = 3), health-related quality-of-life (n = 6), and symptom specific (n = 7) measures.None of the PROMs identified received a high GRADE score for good content. There were 13 PROMs that received a moderate GRADE score. The remaining PROMs either had limited evidence of development and validation within the patient cohorts investigated, or lacked relevance or comprehensiveness needed for routine PROMs collection in a radiotherapy or PBT service.This review highlights that there are a wide variety of PROMs being utilised within radiotherapy research, but most lack specificity to radiotherapy side-effects. There is a risk that by using non-specific PROMs in clinical practice, patients might not receive the supportive care that they need.

Proton therapy planning and image-guidance strategies within a randomized controlled trial for high-risk prostate cancer

The Danish Prostate Cancer Group is launching the randomized trial, PROstate PROTON Trial 1 (NCT05350475), that compares photons and protons to the prostate and pelvic lymph nodes in treatment of high-risk prostate cancer. The aim of the work described in this paper was, in preparation of this trial, to establish a strategy for conventionally fractionated proton therapy of prostate and elective pelvic lymph nodes that is feasible and robust. Proton treatments are image-guided based on gold fiducial markers and on-board imaging systems in line with current practice. Our established proton beam configuration consists of four coplanar fields; two posterior oblique fields and two lateral oblique fields, chosen to minimize range uncertainties associated with penetrating a varying amount of material from both treatment couch and patient body. Proton plans are robustly optimized to ensure target coverage while keeping normal tissue doses as low as is reasonably achievable throughout the course of treatment. Specific focus is on dose to the bowel as a reduction in gastrointestinal toxicity is the primary endpoint of the trial. Strategies have been established using previously treated patients and will be further investigated and evaluated through the ongoing pilot phase of the trial.

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.

Proton versus photon radiation therapy: A clinical review

While proton radiation therapy offers substantially better dose distribution characteristics than photon radiation therapy in certain clinical applications, data demonstrating a quantifiable clinical advantage is still needed for many treatment sites. Unfortunately, the number of patients treated with proton radiation therapy is still comparatively small, in some part due to the lack of evidence of clear benefits over lower-cost photon-based treatments. This review is designed to present the comparative clinical outcomes between proton and photon therapies, and to provide an overview of the current state of knowledge regarding the effectiveness of proton radiation therapy.

Does particle radiation have superior radiobiological advantages for prostate cancer cells? A systematic review of in vitro studies

BACKGROUND

Charged particle beams from protons to carbon ions provide many significant physical benefits in radiation therapy. However, preclinical studies of charged particle therapy for prostate cancer are extremely limited. The aim of this study was to comprehensively investigate the biological effects of charged particles on prostate cancer from the perspective of in vitro studies.

METHODS

We conducted a systematic review by searching EMBASE (OVID), Medline (OVID), and Web of Science databases to identify the publications assessing the radiobiological effects of charged particle irradiation on prostate cancer cells. The data of relative biological effectiveness (RBE), surviving fraction (SF), standard enhancement ratio (SER) and oxygen enhancement ratio (OER) were extracted.

RESULTS

We found 12 studies met the eligible criteria. The relative biological effectiveness values of proton and carbon ion irradiation ranged from 0.94 to 1.52, and 1.67 to 3.7, respectively. Surviving fraction of 2 Gy were 0.17 ± 0.12, 0.55 ± 0.20 and 0.53 ± 0.16 in carbon ion, proton, and photon irradiation, respectively. PNKP inhibitor and gold nanoparticles were favorable sensitizing agents, while it was presented poorer performance in GANT61. The oxygen enhancement ratio values of photon and carbon ion irradiation were 2.32 ± 0.04, and 1.77 ± 0.13, respectively. Charged particle irradiation induced more G0-/G1- or G2-/M-phase arrest, more expression of γ-H2AX, more apoptosis, and lower motility and/or migration ability than photon irradiation.

CONCLUSIONS

Both carbon ion and proton irradiation have advantages over photon irradiation in radiobiological effects on prostate cancer cell lines. Carbon ion irradiation seems to have further advantages over proton irradiation.

Comparing bowel and urinary domains of patient-reported quality of life at the end of and 3 months post radiotherapy between intensity-modulated radiotherapy and proton beam therapy for clinically localized prostate cancer

PURPOSE

To prospectively assess acute differences in patient-reported outcomes in bowel and urinary domains between intensity-modulated radiotherapy (IMRT) and proton beam therapy (PBT) for prostate cancer.

METHODS AND MATERIALS

Bowel function (BF), urinary irritative/obstructive symptoms (UO), and urinary incontinence (UI) domains of EPIC-26 were collected in patients with T1-T2 prostate cancer receiving IMRT or PBT at a tertiary cancer center (2015-2018). Mean changes in domain scores were analyzed from pretreatment to the end of and 3 months post-radiotherapy for each modality. A clinically meaningful change was defined as a score change >50% of the baseline standard deviation.

RESULTS

A total of 157 patients receiving IMRT and 105 receiving PBT were included. There were no baseline differences in domain scores between cohorts. At the end of radiotherapy, there was significant and clinically meaningful worsening of BF and UO scores for patients receiving either modality. In the BF domain, the IMRT cohort experienced greater decrement (-13.0 vs -6.7, P < .01), and had a higher proportion of patients with clinically meaningful reduction (58.4% vs 39.5%, P = .01), compared to PBT. At 3 months post-radiotherapy, the IMRT group had significant and clinically meaningful worsening of BF (-9.3, P < .001), whereas the change in BF score of the PBT cohort was no longer significant or clinically meaningful (-1.2, P = .25). There were no significant or clinically meaningful changes in UO or UI 3 months post-radiotherapy.

CONCLUSIONS

PBT had less acute decrement in BF than IMRT following radiotherapy. There was no difference between the two modalities in UO and UI.