Toxicity and risk factors after combined high-dose-rate brachytherapy and external beam radiation therapy in men ≥75 years with localized prostate cancer

Toxicity of dose-escalated radiotherapy up to 84 Gy for prostate cancer

PURPOSE

The outcome of radiotherapy (RT) for prostate cancer (PCA) depends on the delivered dose. While the evidence for dose-escalated RT up to 80 gray (Gy) is well established, there have been only few studies examining dose escalation above 80 Gy. We initiated the present study to assess the safety of dose escalation up to 84 Gy.

METHODS

In our retrospective analysis, we included patients who received dose-escalated RT for PCA at our institution between 2016 and 2021. We evaluated acute genitourinary (GU) and gastrointestinal (GI) toxicity as well as late GU and GI toxicity.

RESULTS

A total of 86 patients could be evaluated, of whom 24 patients had received 80 Gy and 62 patients 84 Gy (35 without pelvic and 27 with pelvic radiotherapy). Regarding acute toxicities, no > grade 2 adverse events occurred. Acute GU/GI toxicity of grade 2 occurred in 12.5%/12.5% of patients treated with 80 Gy, in 25.7%/14.3% of patients treated with 84 Gy to the prostate only, and in 51.9%/12.9% of patients treated with 84 Gy and the pelvis included. Late GU/GI toxicity of grade ≥ 2 occurred in 4.2%/8.3% of patients treated with 80 Gy, in 7.1%/3.6% of patients treated with 84 Gy prostate only, and in 18.2%/0% of patients treated with 84 Gy pelvis included (log-rank test p = 0.358).

CONCLUSION

We demonstrated that dose-escalated RT for PCA up to 84 Gy is feasible and safe without a significant increase in acute toxicity. Further follow-up is needed to assess late toxicity and survival.

Irradiation of localized prostate cancer in the elderly: A systematic literature review

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Oncological benefit for elderly patients with optimal treatment.

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Elderly patients often received inadequate treatment.

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Elderly comorbidities can influence oncological outcomes and treatment tolerance.

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Optimal curative treatment after oncogeriatric assessment.

Purpose

To analyze the literature that addresses radiation therapy for intermediate and high-risk prostate cancer (PC) in the elderly.

Patients and methods

A PubMed literature search was conducted including articles from 01/01/2000 to 30/06/21, with the following keywords: PC, radiotherapy/brachytherapy and elderly. The analysis mainly focused on the issue of under-treatment in the elderly and the benefit/risk balance of irradiation.

Results

Of the 176 references analyzed, 24 matched the selection criteria. The definition of “elderly patient” varied from 70 to 80 years. The analysis was impacted by the inhomogeneous primary end points used in each cohort. Age was often an obstacle to radical treatment, with a subsequent risk of under-treatment, particularly in patients with a poorer prognosis. However, comparable elderly oncological outcomes were compared to younger patients, both with external beam radiotherapy alone or combined with brachytherapy boost. Late toxicity rates are low and most often comparable to younger populations. However, a urinary over- toxicity was observed in the super-elderly (>80 years) after brachytherapy boost. The use of ADT should be considered in light of comorbidities, and may even be deleterious in some patients.

Conclusion

Due to the increase in life expectancy, the management of PC in the elderly is a challenge for patients, clinicians and health insurance payers. Except for unfit men, elderly patients remain candidates for optimal curative treatment (i.e. regardless of age) after oncogeriatric assessment. More solid data from prospective trials conducted specially in this population will provide better guidance in our daily clinical practice.

High-Dose-Rate brachytherapy boost for elderly patients with intermediate to high-risk prostate cancer: 5-year clinical outcome of the PROSTAGE cohort

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Intermediate/high risk elderly prostate cancer benefits less from received standards of care.

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Age is an independent factor for disease control and tolerance.

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Brachytherapy boost remains efficient and feasible in the elderly.

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Careful discussion for super elderly patients (>80 y) is warranted.

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Oncogeriatric assessment is necessary to identify best candidates.

Purpose

To analyze the oncological outcome in elderly (>70 years) prostate cancer after high-dose rate brachytherapy (HDB) boost.

Materials/methods

In this retrospective study, patients with intermediate (IR) and high-risk (HR) prostate cancer underwent external beam radiation therapy (EBRT) followed by HDB boost with/without androgen deprivation therapy (ADT). The impact of age (≤70y vs. > 70y) was investigated. Oncological outcome focused on biochemical relapse-free survival (bRFS), cause-specific (CSS) and overall survival (OS). Late genito-urinary (GU) and gastro-intestinal (GI) toxicities were investigated.

Results

From 07/08 to 01/22, 518 pts received a HDB boost, and 380 were analyzed (≤70y:177pts [46.6%] vs. > 70y:203pts [53.4%]). Regarding NCCN classification, 98 pts (≤70y: 53pts; >70y: 45pts; p = 0.107) and 282 pts (≤70y: 124pts; >70y: 158pts; p = NS) were IR and HR pts respectively. Median EBRT dose was 46 Gy [37.5–46] in 23 fractions [14–25]. HDB boost delivered a single fraction of 14/15 Gy (79%). ADT was used in 302 pts (≤70y: 130pts; >70y: 172pts; p = 0.01). With MFU of 72.6 months [67–83] for the whole cohort, 5-y bRFS, 5-y CSS and 5-y OS were 88% [85–92], 99% [97–100] and 94% [92–97] respectively; there was no statistical difference between the two age groups except for 5-y CSS (p = 0.05). Late GU and GI toxicity rates were 32.4% (G ≥ 3 7.3%) and 10.1% (no G3) respectively.

Conclusions

For IR and HR prostate cancers, HDB boost leads to high rates of disease control with few late G ≥ 3 GU/GI toxicities. For elderly pts, HDB boost remains warranted mainly in HR pts, while competing comorbidity factors influence OS.

Survival rates with external beam radiation therapy in newly diagnosed elderly metastatic prostate cancer patients

BACKGROUND

The survival benefit of primary external beam radiation therapy (EBRT) has never been formally tested in elderly men who were newly diagnosed with metastatic prostate cancer (mPCa). We hypothesized that elderly patients may not benefit of EBRT to the extent as younger newly diagnosed mPCa patients, due to shorter life expectancy.

METHODS

We relied on Surveillance, Epidemiology and End Results (2004-2016) to identify elderly newly diagnosed mPCa patients, aged >75 years. Kaplan-Meier, univariable and multivariable Cox regression models, as well as Competing Risks Regression models tested the effect of EBRT versus no EBRT on overall mortality (OM) and cancer-specific mortality (CSM).

RESULTS

Of 6556 patients, 1105 received EBRT (16.9%). M1b stage was predominant in both EBRT (n = 823; 74.5%) and no EBRT (n = 3908; 71.7%, p = 0.06) groups, followed by M1c (n = 211; 19.1% vs. n = 1042; 19.1%, p = 1) and M1a (n = 29; 2.6% vs. n = 268; 4.9%, p < 0.01). Median overall survival (OS) was 23 months for EBRT and 23 months for no EBRT (hazard ratio [HR]: 0.97, p = 0.6). Similarly, median cancer-specific survival (CSS) was 29 months for EBRT versus 30 months for no EBRT (HR: 1.04, p = 0.4). After additional multivariable adjustment, EBRT was not associated with lower OM or lower CSM in the entire cohort, as well as after stratification for M1b and M1c substages.

CONCLUSIONS

In elderly men who were newly diagnosed with mPCa, EBRT does not affect OS or CSS. In consequence, our findings question the added value of local EBRT in elderly newly diagnosed mPCa patients.

Non-cancer mortality in elderly prostate cancer patients treated with combination of radical prostatectomy and external beam radiation therapy

BACKGROUND

To test for rates of other cause mortality (OCM) and cancer-specific mortality (CSM) in elderly prostate cancer (PCa) patients treated with the combination of radical prostatectomy (RP) and external beam radiation therapy (EBRT) versus RP alone, since elderly PCa patients may be over-treated.

METHODS

Within the Surveillance, Epidemiology and End Results database (2004-2016), cumulative incidence plots, after propensity score matching for cT-stage, cN-stage, prostate specific antigen, age and biopsy Gleason score, and multivariable competing risks regression models (socioeconomic status, pathological Gleason score) addressed OCM and CSM in patients (70-79, 70-74, and 75-79 years) treated with RP and EBRT versus RP alone.

RESULTS

Of 18,126 eligible patients aged 70-79 years, 2520 (13.9%) underwent RP and EBRT versus 15,606 (86.1%) RP alone. After propensity score matching, 10-year OCM rates were respectively 27.9 versus 20.3% for RP and EBRT versus RP alone (p < .001), which resulted in a multivariable HR of 1.4 (p < .001). Moreover, 10-year CSM rates were respectively 13.4 versus 5.5% for RP and EBRT versus RP alone. In subgroup analyses separately addressing 70-74 year old and 75-79 years old PCa patients, 10-year OCM rates were 22.8 versus 16.2% and 39.5 versus 24.0% for respectively RP and EBRT versus RP alone patients (all p < .001).

CONCLUSION

Elderly patients treated with RP and EBRT exhibited worrisome rates of OCM. These higher than expected OCM rates question the need for combination therapy (RP and EBRT) in elderly PCa patients and indicate the need for better patient selection, when combination therapy is contemplated.

Comparative effectiveness of surgery and radiotherapy for survival of patients with clinically localized prostate cancer: A population-based coarsened exact matching retrospective cohort study

Radical prostatectomy and radiotherapy are currently the main treatment options for localized prostate cancer. However, no large cohort study comparing surgery and radiation has been performed in Japan or Asia. The objective of the current study was to compare the survival outcomes of patients with clinically localized prostate cancer and in elderly and young patients receiving surgery and radiotherapy. The survival outcomes of patients with localized prostate cancer (age at diagnosis ≤79 years, clinical T1-3) initially treated with surgery or radiotherapy were retrospectively analyzed. Data were collected from the population-based cancer registry of the Kanagawa Prefecture, Japan. A 1:1 coarsened exact matching of age at diagnosis, clinical T stage and cancer differentiation was performed between the two treatment groups. Patients were also categorized into two subgroups by age using a cutoff of 70 years for analysis. The cohort comprised 4,810 patients aged 50-79 years. No significant difference in cancer-specific survival (CSS) was observed between the two groups (P=0.612). However, the surgery group had significantly better overall survival (OS; P=0.004). When stratified for age, similar tendencies were observed in the elderly group (aged 70-79 years; CSS, P=0.961 and OS, P=0.007). No significant difference in either CSS or OS was identified in the younger group (P=0.550 and P=0.408, respectively). Intrinsic deaths were more likely to occur in elderly patients treated with radiotherapy than those undergoing surgery (69.3 vs. 78.2%; P=0.128). The results indicated that surgery provided significantly better OS than radiotherapy, particularly among the elderly. However, no significant difference was observed in CSS. These results should be interpreted with caution, given that some important factors were unavailable in the present study, such as prostate-specific antigen values and Gleason scores. Prospective trials evaluating these therapies are warranted.

4D perfusion CT of prostate cancer for image-guided radiotherapy planning: A proof of concept study

Purpose

Advanced forms of prostate cancer (PCa) radiotherapy with either external beam therapy or brachytherapy delivery techniques aim for a focal boost and thus require accurate lesion localization and lesion segmentation for subsequent treatment planning. This study prospectively evaluated dynamic contrast-enhanced computed tomography (DCE-CT) for the detection of prostate cancer lesions in the peripheral zone (PZ) using qualitative and quantitative image analysis compared to multiparametric magnet resonance imaging (mpMRI) of the prostate.

Methods

With local ethics committee approval, 14 patients (mean age, 67 years; range, 57–78 years; PSA, mean 8.1 ng/ml; range, 3.5–26.0) underwent DCE-CT, as well as mpMRI of the prostate, including standard T2, diffusion-weighted imaging (DWI), and DCE-MRI sequences followed by transrectal in-bore MRI-guided prostate biopsy. Maximum intensity projections (MIP) and DCE-CT perfusion parameters (CTP) were compared between healthy and malignant tissue. Two radiologists independently rated image quality and the tumor lesion delineation quality of PCa using a five-point ordinal scale. MIP and CTP were compared using visual grading characteristics (VGC) and receiver operating characteristics (ROC)/area under the curve (AUC) analysis.

Results

The PCa detection rate ranged between 57 to 79% for the two readers for DCE-CT and was 92% for DCE-MRI. DCE-CT perfusion parameters in PCa tissue in the PZ were significantly different compared to regular prostate tissue and benign lesions. Image quality and lesion visibility were comparable between DCE-CT and DCE-MRI (VGC: AUC 0.612 and 0.651, p>0.05).

Conclusion

Our preliminary results suggest that it is feasible to use DCE-CT for identification and visualization, and subsequent segmentation for focal radiotherapy approaches to PCa.