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Previously a phase III trial of a hydrogel rectal spacer during prostate radiation therapy found decreased toxicity and a clinically significant improvement in bowel quality of life (QOL) at 3 years by the Expanded Prostate Cancer Index. We performed a secondary analysis to identify men less likely to benefit.Clinical and dosimetric data for the 222 patients enrolled on the SpaceOAR phase III trial were analyzed. The volume of rectum treated to 70 Gy (V70) and the quantitative analysis of normal tissue effects in the clinic (QUANTEC) rectal dose goals were used as surrogates for clinical benefit and plan quality. Mean bowel QOL was assessed at 15 and 36 months posttreatment and the likelihood of 1× (5 points) or 2× (10 points) minimally important difference changes were assessed.Rectal V70 was correlated with physician scored toxicity (P = .033) and was used as a surrogate for plan quality. There was no correlation between prostate volume and rectal V70 (r = 0.077). Rectal V70 pre- and post-hydrogel was 13% and 3% for the smallest prostates (40 mL) and 12% and 2% for the largest (80 mL). The relative reduction in rectal V70 of 78% did not vary by prespacer V70, but the absolute reduction was greater for a higher V70. All spacer plans met the 5 QUANTEC rectal dose constraints, although 92% of control plans met all constraints. At 3 years, those not meeting all QUANTEC goals had a 15.0-point (standard deviation 15.1) decline, control patients meeting QUANTEC goals had a 4.0-point (9.5) decline, and spacer had0.5 (7.6; P.01). Previous surgery was not correlated with QOL (P = .8). Across prognostic groups, including age, body mass index, previous surgery, target volume, or quality of radiation plans, there was no statistically significant heterogeneity in the relative benefit of spacer in decreasing the risk of 1× or 2× the minimally important difference declines.There was little heterogeneity in the likelihood of spacer reducing the risk of declines in bowel QOL across clinical and dosimetric variables. Even for the95% of plans meeting QUANTEC rectal criteria, hydrogel spacer provided potentially meaningful benefits.

Purpose The purpose of this study was to delineate a scoring system to maximize the ethical allocation of proton beam therapy (PBT) and determine what factors are associated with receipt of PBT, including the role of specific insurance providers. Methods and Materials Our scoring system was developed in collaboration with a multidisciplinary panel of experts. Patients submitted for PBT consideration were assigned a score by committee at a weekly peer-reviewed session at a time when our center was operating at capacity. Univariate analysis and multivariable analysis of initial and final insurance response were performed. Results One hundred ninety-seven patients were prospectively reviewed. Ninety-three percent of patients with Medicaid coverage, 88% of patients with Medicare, and 78% of patients with private insurance were ultimately approved for PBT. Median time to final insurance response was 12 days (interquartile range, 9-18 days) for patients who were ultimately denied PBT coverage. Having primary provider C (odds ratio [OR], 14; 95% confidence interval [CI], 1.20-1.96; P = .033) or third party providers A (OR, 4.22; 95% CI, 1.71-10.9; P = .002) or B (OR, 5.28; 95% CI, 1.56-17.2; P = .006) was significantly associated with final insurance denial for PBT on univariate analysis. Total score (OR, 0.79; 95% CI, 0.67-0.90; P = .002) and having coverage through third party provider A (OR, 24.2; 95% CI, 9.51-68.9; P Conclusions Our scoring system was significantly associated with receipt of proton beam therapy. Certain insurance providers are less likely to approve PBT for patients, all else being equal. Such a scoring system could be implemented effectively at other PBT facilities, and additional work is needed in ensuring patients with the most to gain from PBT will be approved by their insurance providers.

Purpose This study aimed to evaluate the impact on spine growth in children with medulloblastoma using either photon or electron craniospinal irradiation (CSI). Methods and materials This was a single institution retrospective review of children who were treated with CSI for medulloblastoma. Spine growth was measured on magnetic resonance imaging scans at defined locations on the basis of a published predictive model of spine growth after CSI. Differences between spine growth in the anterior, middle, and posterior aspect of the designated vertebral segments were also assessed. Differences between the groups treated with photons or electrons were assessed with student’s t test. Results A total of 19 patients (10 patients treated with electrons and 9 with photons) with a median follow-up time of 45.5 months (confidence interval, 34.9-55.1 months) were evaluated. Patients treated with electrons were younger than those who received photons (5.1 years [range, 3.8-9.0 years] vs 9.6 years [range, 3.5-12.9 years]); however, there were no differences in other clinical characteristics, treatment, or follow-up between the groups. Spine growth rate for patients treated with electrons fit the predictive model (104% ± 5.2%), but patients treated with photons had growth that was faster than predicted by the model (150% ± 47%) and different from that observed with electrons. The differences between treatment the modalities were statistically significant (P = .03). For patients treated with photons, there were no statistical differences between the growth rate of the anterior vertebral body compared with the posterior aspect, but for patients treated with electrons, a faster spine growth in the anterior L1-L5 lumbar spine was observed compared with the posterior lumbar spine (3.90 vs 2.52 mm/year; P = .006) without differences in the cervical or thoracic spine. Conclusions The use of electrons to treat the craniospinal axis in children with medulloblastoma resulted in no significant difference in spine growth compared with the predicted spine growth on the basis of previously published models using photons, but with a clinically insignificant faster spine growth rate in the anterior lumbar spine.

Purpose The use of stereotactic body radiation therapy (SBRT) for prostate cancer has been reported predominantly from single institutional studies, although concerns for broader adoption exist. Methods and materials From 2011 through 2013, 66 men were accrued to a phase 2 trial at 5 centers. SBRT consisted of 5 fractions of 7.4 Gy to a total dose of 37 Gy using conventional linear accelerators. Electromagnetic transponders were used for motion management. Health-related quality of life (HRQOL) was evaluated via the Expanded Prostate Cancer Index Composite 26 questionnaire. Acute and late toxicities were collected according to Common Terminology Criteria for Adverse Events, version 4.0. Linear mixed modeling was performed to assess changes in HRQOL over time. Results Median follow-up was 36 months. All men had low- or intermediate-risk disease. There have been 0 biochemical recurrences. No grade 3 urinary or bowel toxicity was reported. Twenty-three percent of patients had acute grade 2 urinary toxicity, with 9% late grade 2 urinary toxicity. Four percent and 5% experienced acute or late grade 2+ bowel toxicity, respectively. Urinary bother and bowel HRQOL transiently decreased during the first 6 to 12 months post-SBRT, and then returned to baseline. In men with good erectile function at baseline, sexual HRQOL declined during the first 6 months and stabilized thereafter. On linear mixed modeling, the strongest predictor of sustained bowel and sexual HRQOL was baseline HRQOL. Conclusions In this multi-institutional phase 2 clinical trial using continuous real-time evaluation of prostate motion, prostate SBRT has excellent intermediate-term tumor control with mild and expected treatment-related side effects.

We previously reported the results of a phase 3 trial evaluating a prostate/rectal hydrogel spacer during prostate intensity modulated radiation therapy, which resulted in decreased rectal dose and toxicity and less decline in bowel quality of life (QOL). A secondary analysis was performed to correlate penile bulb dose and sexual QOL.Sexual QOL was measured with the Expanded Prostate Cancer Index Composite (EPIC) by mean scores, the proportion of patients with a minimal clinically important difference (MID), and analyses of the different items composing the sexual domain.A total of 222 men enrolled with median follow-up of 37 months. Hydrogel reduced penile bulb mean dose, maximum dose, and percentage of penile bulb receiving 10 to 30 Gy (all P.05) with mean dose indirectly correlated with erections sufficient for intercourse at 15 months (P = .03). Baseline EPIC was low (53 [standard deviation ± 24]) with no difference between arms (P.1). A total of 41% (88/222) of men had adequate baseline sexual QOL (EPIC60 (mean, 77 [± 8.3]). This subgroup at 3 years had better sexual function (P = .03) with a spacer with a smaller difference in sexual bother (P = .1), which resulted in a higher EPIC summary on the spacer arm (58 [±24.1] vs control 45 [± 24.4]) meeting threshold for MID without statistical significance (P = .07). There were statistically nonsignificant differences favoring spacer for the proportion of men with MID and 2× MID declines in sexual QOL with 53% vs 75% having an 11-point decline (P = .064) and 41% vs 60% with a 22-point decline (P = .11). At 3 years, more men potent at baseline and treated with spacer had "erections sufficient for intercourse" (control 37.5% vs spacer 66.7%, P = .046) as well as statistically higher scores on 7 of 13 items in the sexual domain (all P.05).The use of a hydrogel spacer decreased dose to the penile bulb, which was associated with improved erectile function compared with the control group based on patient-reported sexual QOL.

Purpose To investigate the prognostic utility of the Stephenson nomogram for clinically relevant endpoints, freedom from metastasis (FFM), and prostate cancer–specific survival (PCSS) in patients treated with salvage external beam radiation therapy (SRT) following a rising prostate-specific antigen (PSA) after radical prostatectomy (RP). Methods and materials From an institutional cohort of 575 patients treated with SRT between 1986 and 2010, the Stephenson nomogram variables were retrospectively collected and available for 179 patients. The prognostic impact of the Stephenson nomogram on 6-year freedom from biochemical failure (FFBF), FFM, and PCSS was assessed on univariate and multivariate analysis using Kaplan-Meier and Cox proportional hazards models. The prognostic utility of the Stephenson nomogram was compared with individual pretreatment, treatment, and clinical characteristics using concordance indices. Results In the 179 patients with all available nomogram variables, median follow-up was 85.0 months (interquartile range [IQR], 53-113) and 6-year FFBF, FFM, and PCSS were 38% (95% confidence interval [CI], 30-46), 79% (95% CI, 73-85), and 96% (95% CI, 92-100), respectively. Univariate analysis, demonstrated that the Stephenson nomogram, as a continuous variable and as a risk stratified group, was prognostic of FFBF (both, P P P ≤ .0005). When analyzing individual Stephenson nomogram variables, multivariate analysis revealed that positive surgical margins ( P = .02; hazard ratio [HR], 0.4; 95% CI, 0.2-0.8) and pre-RT PSA ( P = .0001; HR, 1.6; 95% CI, 1.3-2.0) were prognostic for FFM, while pre-RT PSA ( P = .03; HR, 1.2; 95% CI, 1.0-1.4) was the only prognostic variable for PCSS. Concordance indices revealed the Stephenson nomogram to have superior prognostic capability for biochemical failure (0.71), distant metastasis (0.75), and prostate cancer–specific mortality (0.75) when compared with individual variables (BF all ≤0.65, DM all ≤0.67, PCSM all ≤0.71). Conclusions For patients treated with SRT for a rising PSA postprostatectomy, the Stephenson nomogram is an appropriate prognostic tool for estimating the response to treatment; however, there remains a need for improvement in current and future nomograms.

Little is known regarding the prognostic capability of prostate-specific antigen (PSA) nadir (nPSA) and time to nPSA (TnPSA) following salvage radiation therapy (SRT) for biochemical failure (BF) postradical prostatectomy (RP). We sought to assess their prognostic significance in this setting.A total of 448 patients who received SRT without androgen deprivation therapy at a single academic institution were included in this retrospective analysis. Univariate analysis and multivariate Cox proportional hazards models were used to assess BF, distant metastasis (DM), prostate cancer-specific death (PCSD), and overall survival (OS). A prognostic nomogram incorporating nPSA and TnPSA was developed and validated in randomly allocated training and validation cohorts.Median follow-up post-SRT was 64 months. Median nPSA and TnPSA were undetectable and 6.7 months, respectively. On univariate analysis, a detectable nPSA (P.01) and TnPSA6 months (P.01) were predictive of all outcomes. In a training cohort, a 14-point nomogram incorporating detectable nPSA, TnPSA, Gleason score, pre-radiation therapy PSA, and seminal vesicle invasion predicted BF (hazard ratio[HR], 1.4; P.0001), DM (HR, 1.3; P.0001), PCSD (HR, 1.3; P.0001), and decreased OS (HR, 1.2; P.0001). Adding nPSA and TnPSA improved the prognostic value of the nomogram compared to using clinical predictors only. The nomogram was evaluated in a validation cohort where it was predictive of BF (c-index = 0.77), DM (0.73), and PCSD (0.69).Patients with a detectable nPSA also having a TnPSA6 months post-SRT are at high-risk for DM, PCSD, and decreased OS. These patients are unlikely to have clinically localized disease and should be considered for initiation of systemic therapies.