Predictors of multidomain decline in health-related quality of life after stereotactic body radiation therapy (SBRT) for prostate cancer

Risk factors for the long-term persistent genitourinary toxicity after stereotactic body radiation therapy for localized prostate cancer: A single-center, retrospective study of 306 patients

OBJECTIVES

To identify risk factors for the long-term persistent genitourinary toxicity (GUT) after stereotactic body radiation therapy (SBRT) for localized prostate cancer (PCa).

METHODS

A total of 306 patients who underwent SBRT at our institution between March 2017 and April 2022 were retrospectively evaluated. SBRT was performed at 35 Gy in five fractions over 5 or 10 days. Factors related to the long-term persistence of acute GUT after SBRT were analyzed.

RESULTS

During the median follow-up period of 39.1 months, 203 (66%) patients experienced any grade of acute GUT, which remained in 78 (26%) patients 6 months after SBRT. Multivariate analysis revealed that age ≥75 years was consistently a significant independent risk factor for any grade of acute GUT 6, 12, and 24 months after SBRT (hazard ratio [HR] 2.31, p = 0.010; HR 2.84, p = 0001; and HR 3.05, p = 0.009, respectively). Older age was not a significant risk factor for the development of grade ≥2 acute GUT. The duration of acute GUT was significantly longer in the older group than in the nonolder group (median duration = 234 vs. 61 days, p < 0.001), and the incidence of persistent GUT was significantly more frequent in the older group beyond 6 months after SBRT.

CONCLUSIONS

Older age is a significant independent risk factor for the long-term persistent GUT after SBRT for localized PCa.

Five-Year Patient-Reported Outcomes in NRG Oncology RTOG 0938, Evaluating Two Ultrahypofractionated Regimens for Prostate Cancer

PURPOSE

There is considerable interest in very short (ultrahypofractionated) radiation therapy regimens to treat prostate cancer based on potential radiobiological advantages, patient convenience, and resource allocation benefits. Our objective is to demonstrate that detectable changes in health-related quality of life measured by the bowel and urinary domains of the Expanded Prostate Cancer Index Composite (EPIC-50) were not substantially worse than baseline scores.

METHODS AND MATERIALS

NRG Oncology's RTOG 0938 is a nonblinded randomized phase 2 study of National Comprehensive Cancer Network low-risk prostate cancer in which each arm is compared with a historical control. Patients were randomized to 5 fractions (7.25 Gy in 2 week and a day [twice a week]) or 12 fractions (4.3Gy in 2.5 weeks [5 times a week]). Secondary objectives assessed patient-reported toxicity at 5 years using the EPIC. Chi-square tests were used to assess the proportion of patients with a deterioration from baseline of >5 points for bowel, >2 points for urinary, and >11 points for sexual score.

RESULTS

The study enrolled 127 patients to 5 fractions (121 eligible) and 128 patients to 12 fractions (125 eligible). The median follow-up for all patients at the time of analysis was 5.38 years. The 5-year frequency for >5 point change in bowel score were 38.4% (P = .27) and 23.4% (P = 0.98) for 5 and 12 fractions, respectively. The 5-year frequencies for >2 point change in urinary score were 46.6% (P = .15) and 36.4% (P = .70) for 5 and 12 fractions, respectively. For 5 fractions, 49.3% (P = .007) of patients had a drop in 5-year EPIC-50 sexual score of ≥11 points; for 12 fractions, 54% (P < .001) of patients had a drop in 5-year EPIC-50 sexual score of ≥11 points. Disease-free survival at 5 years is 89.6% (95% CI: 84.0-95.2) in the 5-fraction arm and 92.3% (95% CI: 87.4-97.1) in the 12-fraction arm. There was no late grade 4 or 5 treatment-related urinary or bowel toxicity.

CONCLUSIONS

This study confirms that, based on long-term changes in bowel and urinary domains and toxicity, the 5- and 12-fraction regimens are well tolerated. These ultrahypofractionated approaches need to be compared with current standard radiation therapy regimens.

Dosimetric Predictors of Toxicity after Prostate Stereotactic Body Radiotherapy: A Single-Institutional Experience of 145 Patients

The indications for stereotactic body radiotherapy (SBRT) for prostate cancer have increased. However, the relationships between adverse events and risk factors remain unclear. This study aimed to clarify associations between adverse events and dose index for prostate SBRT. Participants comprised 145 patients irradiated with 32-36 Gy in 4 fractions. Radiotherapy-related risk factors such as dose-volume histogram parameters and patient-related risk factors such as T stage and Gleason score were evaluated in a competing risk analysis. Median follow-up duration was 42.9 months. A total of 9.7% had acute Grade ≥ 2 GU toxicities and 4.8% had acute Grade ≥ 2 GI toxicities. A total of 11.1% had late Grade ≥ 2 GU toxicities and 7.6% had late Grade ≥ 2 GI toxicities. Two (1.4%) patients suffered from late Grade 3 GU toxicities. Similarly, two (1.4%) patients suffered from late Grade 3 GI toxicities. Acute GU and GI events correlated with prostate volume and dose to the hottest 10 cc volume (D10cc)/volumes receiving a minimum of 30 Gy (V30 Gy) of rectum, respectively. Late GI toxicity, frequency, and rectal hemorrhage correlated with rectal D0.1 cc/D1 cc, maximum dose to the bladder, and rectal D0.1 cc, respectively. Toxicities after prostate SBRT using 32-36 Gy/4 fractions were acceptable. Our analysis showed that acute toxicities correlated with volume receiving a medium dose level, and late toxicities correlated with highest point dose of organs at risk.

Accumulated bladder wall dose is correlated with patient-reported acute urinary toxicity in prostate cancer patients treated with stereotactic, daily adaptive MR-guided radiotherapy

BACKGROUND AND PURPOSE

Magnetic resonance (MR)-guided linear accelerators (MR-Linac) enable accurate estimation of delivered doses through dose accumulation using daily MR images and treatment plans. We aimed to assess the association between the accumulated bladder (wall) dose and patient-reported acute urinary toxicity in prostate cancer (PCa) patients treated with stereotactic body radiation therapy (SBRT).

MATERIALS AND METHODS

One-hundred-and-thirty PCa patients treated on a 1.5T MR-Linac were included. Patients filled out International Prostate Symptom Scores (IPSS) questionnaires at baseline, 1 month, and 3 months post-treatment. Deformable image registration-based dose accumulation was performed to reconstruct the delivered dose. Dose parameters for both bladder and bladder wall were correlated with a clinically relevant increase in IPSS (≥10 points) and/or start of alpha-blockers within 3 months using logistic regression.

RESULTS

Thirty-nine patients (30%) experienced a clinically relevant IPSS increase and/or started with alpha-blockers. Bladder D5cm³, V_10-35Gy (in %), and D_mean and Bladder wall V_10-35Gy (cm³ and %) and D_mean were correlated with the outcome (odds ratios 1.04-1.33, p-values 0.001-0.044). Corrected for baseline characteristics, bladder V_10-35Gy (in %) and D_mean and bladder wall V_10-35Gy (cm³ and %) and D_mean were still correlated with the outcome (odds ratios 1.04-1.30, p-values 0.001-0.028). Bladder wall parameters generally showed larger AUC values.

CONCLUSION

This is the first study to assess the correlation between accumulated bladder wall dose and patient-reported urinary toxicity in PCa patients treated with MR-guided SBRT. The dose to the bladder wall is a promising parameter for prediction of patient-reported urinary toxicity and therefore warrants prospective validation and consideration in treatment planning.

Health beliefs and engagement in moderate-to-vigorous-intensity physical activity among cancer survivors: a cross-sectional study

PURPOSE

Moderate-to-vigorous-intensity physical activity (PA) can alleviate many adverse side effects and symptoms caused by cancer treatments; yet, most cancer survivors are insufficiently active. Evidence shows that theory-based PA behavior change interventions are more effective than non-theory-based interventions; thus, it is necessary to ascertain modifiable theoretical factors associated with moderate-to-vigorous-intensity PA among cancer survivors. Drawing on the health belief model (HBM), the associations between moderate-to-vigorous-intensity PA and (1) perceived susceptibility to cancer recurrence and health problems, (2) perceived severity of cancer recurrence and health problems, (3) perceived benefits of PA for reducing risk of cancer recurrence and health problems, (4) perceived barriers to PA, and (5) PA barrier self-efficacy among cancer survivors were examined.

METHODS

A total of 123 adult cancer survivors (M_age = 50.1 ± 15.5 years; 82.9% female) completed an online self-report survey assessing sociodemographic and medical characteristics, moderate-to-vigorous-intensity PA, and the HBM constructs. Data were analyzed descriptively and using hierarchical linear regression analysis.

RESULTS

After adjusting for age, sex, body mass index, time since cancer diagnosis, and treatments received, the HBM constructs collectively explained 29% of the variance in moderate-to-vigorous-intensity PA. Perceived benefits of PA (β = .20, 95% CI [1.81, 11.67], p = .007) and PA barrier self-efficacy (β = .42, 95% CI [0.26, 0.53], p < .001) were significantly associated with moderate-to-vigorous-intensity PA.

CONCLUSION

Raising awareness of the benefits of PA for reducing risk of cancer recurrence and health problems and strengthening self-efficacy to overcome PA barriers may help to promote cancer survivors' attainment of moderate-to-vigorous-intensity PA guidelines.

Mood outcomes of a behavioral treatment for urinary incontinence in prostate cancer survivors

PURPOSE

This study aimed to assess whether prostate cancer survivors who received a behavioral intervention to urinary incontinence had experienced a significant mood improvement.

METHODS

One hundred fifty-three prostate cancer survivors with persistent incontinence were included in this secondary data analysis. They were randomly assigned to usual care or interventions that provided pelvic floor muscle exercises and self-management skills. All subjects had measures of anxiety, depression, and anger at baseline, 3 months (post-intervention), and 6 months (follow-up). Negative binomial regression analysis was performed to examine the group status, daily leakage frequency at 3 months, and their interactions at 3 months as predictors for mood outcomes at 6 months, controlling for demographic and medical variables.

RESULTS

The main effect of daily leakage frequency at 3 months significantly predicted anxiety at 6 months (p < .01). The group main effect on any mood outcomes at 6 months was not statistically significant. The interaction between the group and 3-month leakage had a significant effect on anxiety; intervention subjects achieving a significant leakage reduction at 3 months exhibited significantly less anxiety at 6 months than other subjects (p = .04). Age, employment status, and receiving surgery at baseline were significantly associated with less anxiety, depression, and anger at 6 months.

CONCLUSIONS

Reduced urinary incontinence significantly predicted less anxiety, especially among the intervention subjects. The findings suggest a significant association between a behavioral therapy of urinary incontinence and anxiety reduction in prostate cancer survivors.

Patient Reported Outcomes in NRG Oncology RTOG 0938, Evaluating Two Ultrahypofractionated Regimens for Prostate Cancer

PURPOSE

There is considerable interest in very short (ultrahypofractionated) radiation therapy regimens to treat prostate cancer based on potential radiobiological advantages, patient convenience, and resource allocation benefits. Our objective is to demonstrate that detectable changes in health-related quality of life measured by the bowel and urinary domains of the Expanded Prostate Cancer Index Composite (EPIC-50) were not substantially worse than baseline scores.

METHODS AND MATERIALS

NRG Oncology's RTOG 0938 is a nonblinded randomized phase 2 study of National Comprehensive Cancer Network low-risk prostate cancer in which each arm is compared with a historical control. Patients were randomized to 5 fractions (7.25 Gy in 2 weeks) or 12 fractions (4.3 Gy in 2.5 weeks). The co-primary endpoints were the proportion of patients with a change in EPIC-50 bowel score at 1 year (baseline to 1 year) >5 points and in EPIC-50 urinary score >2 points tested with a 1-sample binomial test.

RESULTS

The study enrolled 127 patients to 5 fractions (121 analyzed) and 128 patients to 12 fractions (125 analyzed). Median follow-up for all patients at the time of analysis was 3.8 years. The 1-year frequency for >5 point change in bowel score were 29.8% (P < .001) and 28.4% (P < .001) for 5 and 12 fractions, respectively. The 1-year frequencies for >2 point change in urinary score were 45.7% (P < .001) and 42.2% (P < .001) for 5 and 12 fractions, respectively. For 5 fractions, 32.9% of patients had a drop in 1-year EPIC-50 sexual score of ≥11 points (P = .34); for 12 fractions, 30.9% of patients had a drop in 1-year EPIC-50 sexual score of ≥ 11 points (P = .20). Disease-free survival at 2 years is 99.2% (95% confidence interval: 97.5-100) in the 5-fraction arm and 97.5% (95% confidence interval: 94.6-100) in the 12-fraction arm. There was no late grade 4 or 5 treatment-related urinary or bowel toxicity.

CONCLUSIONS

This study confirms that, based on changes in bowel and urinary domains and toxicity (acute and late), the 5- and 12-fraction regimens are well tolerated. These ultrahypofractionated approaches need to be compared with current standard radiation therapy regimens.

Erectile function after stereotactic body radiotherapy for localized prostate cancer

OBJECTIVE

To elucidate the functional erection rate after prostate stereotactic body radiotherapy (SBRT) and to develop a comprehensive prognostic model of outcomes after treatment.

PATIENTS AND METHODS

Between 2008 and 2013, 373 consecutive men with localized prostate cancer were treated with SBRT at a single academic institution as part of a prospective clinical trial or prospective registry. Prospective longitudinal patient-reported health-related quality of life (HRQoL) data was collected using the Expanded Prostate Cancer Index Composite (EPIC)-26 instrument. Functional erections were strictly defined as 'firm enough for intercourse' according to EPIC-26. Detailed comorbidity data were also collected. Logistic regression models were used to predict 24- and 60-month functional erection rates. Observed erection rates after SBRT were compared with those after other radiation therapies (external beam radiation therapy [EBRT] and brachytherapy) using prospectively validated models.

RESULTS

The median (interquartile range) follow-up was 56 (37-73) months and the response rate at 2 years was 84%. For those with functional erections at baseline, 57% and 45% retained function at 24 and 60 months, respectively. On multivariable analysis for 24-month erectile function, significant variables included higher baseline sexual HRQoL (adjusted odds ratio [aOR] 1.55 per 10 points, 95% confidence interval [CI] 1.37-1.74; P < 0.001) and older age (aOR 0.66 per 10 years, 95% CI 0.43-1.00; P = 0.05). At 60 months, baseline HRQoL and age remained associated with erectile function, along with body mass index (aOR 0.45, 95% CI 0.26-0.78; P < 0.001). The 24- and 60-month models had excellent discrimination (c-index 0.81 and 0.84, respectively). Erection rates after SBRT were not statistically different from model-predicted rates after EBRT or brachytherapy for the whole cohort and the cohort with baseline erectile function.

CONCLUSIONS

Intermediate- to long-term post-SBRT erectile function results are promising and not significantly different from other radiotherapy techniques. Clinicians can use our prognostic model to counsel patients regarding expected erectile function after SBRT.

Symptoms predicting health-related quality of life in prostate cancer patients treated with localized radiation therapy

Objective

Patient-reported health-related quality-of-life (HRQOL) measures can provide guidance for treatment decision making, symptom management, and discharge planning. HRQOL is often influenced by the distress experienced by patients from disease or treatment-related symptoms. This study aimed to identify symptoms that can predict changes in HRQOL in men undergoing external beam radiation therapy (EBRT) for nonmetastatic prostate cancer (NMPC).

Methods

Fifty-one men with NMPC scheduled for EBRT were assessed at the baseline, at the midpoint of EBRT, and at the end of EBRT. All participants received 38–42 daily doses of EBRT (five times a week), depending on the stage of their disease. Validated questionnaires were administered to evaluate depressive symptoms, urinary and sexual functions, bowel issues, symptom-related distress, fatigue, and HRQOL. Pearson correlations, repeated-measures ANOVA, and multiple regressions examined the relationships among variables.

Results

Intensification of symptoms and increased symptom-related distress, with a corresponding decline in HRQOL, were observed during EBRT in men with NMPC. Changes in symptoms and symptom distress were associated with changes in HRQOL at the midpoint of EBRT (r=−0.37 to −0.6, P=0.05) and at the end of EBRT (r=−0.3 to −0.47, P=0.01) compared with the baseline. The regression model comprising age, body mass index, Gleason score, T category, androgen-deprivation therapy use, radiation dose received, symptoms (urinary/sexual/bowel problems, fatigue), and overall symptom distress explained 70% of the variance in predicting HRQOL. Urinary problems and fatigue significantly predicted the decline in HRQOL during EBRT.

Conclusion

Identifying specific symptoms that can influence HRQOL during EBRT for NMPC can provide feasible interventional targets to improve treatment outcomes.