A pooled patient-reported outcomes analysis of moderately hypofractionated proton beam therapy and photon-based intensity modulated radiation therapy for low- or intermediate-risk prostate cancer.

BACKGROUND: We sought to characterize and compare late patient-reported outcomes (PROs) after moderately hypofractionated intensity modulated radiation therapy (IMRT) and proton beam therapy (PBT) for localized prostate cancer (PC). METHODS: This multi-institutional analysis included low- or intermediate-risk group PC patients treated with moderately hypofractionated radiation to an intact prostate stratified by treatment modality: IMRT or PBT. The primary outcomes were prospectively collected patient-reported late gastrointestinal (GI) and genitourinary (GU) toxicity assessed by International Prostate Symptom Score (IPSS) and Expanded PC Index Composite (EPIC). Multivariable regression analysis (MVA) controlling for age, race, and risk group tested the effect of time, treatment, and their interaction. RESULTS: 287 IMRT and 485 PBT patients were included. Intermediate risk group (81.2 vs. 68.2%; p < 0.001) and median age at diagnosis (70 vs. 67 years; p < 0.001) were higher in the IMRT group. On MVA, there was no significant difference between modalities. PBT IPSS did not differ from IMRT IPSS at 12 months (odds ratio [OR], 1.19; p = 0.08) or 24 months (OR, 0.99; p = 0.94). PBT EPIC overall GI function at 12 months (OR, 3.68; p = 0.085) and 24 months (OR 2.78; p = 0.26) did not differ from IMRT EPIC overall GI function. At 24 months, urinary frequency was no different between PBT and IMRT groups (OR 0.35; p = 0.096). CONCLUSIONS: This multi-institutional analysis of low- or intermediate-risk PC treated with moderately hypofractionated PBT and IMRT demonstrated low rates of late patient-reported GI and GU toxicities. After covariate adjustment, late GI and GU PROs were not significantly different between PBT or IMRT cohorts.

Local salvage of radiorecurrent prostate cancer.

BACKGROUND: Locally recurrent prostate cancer following primary external beam radiotherapy without distant metastasis is a challenging problem, with no current consensus on the optimal management of these patients. Traditional whole-gland salvage treatments offered up to a 50% 5-year disease-free survival rate but with troubling levels of risk for significant complications. Recent progress in advanced imaging techniques has allowed a more accurate selection of patients with local-only recurrence and a selection of patients that may be suitable for newer partial-gland salvage treatments that may reduce late complications. METHODS: This article reviews advances in patient selection and provides an overview of whole- and partial-gland salvage results from selected recent meta-analyses, multi-institutional series, and studies from centers of excellence for these treatment approaches. RESULTS: Salvage radical prostatectomy produces 5-year relapse-free survival (RFS) rates in the 50%-60% range with severe gastrointestinal (GI) toxicity in < 2% but severe genitourinary (GU) toxicity in 15%-23% of patients. The whole-gland options of high and low dose rate brachytherapy and stereotactic body radiation therapy appear to offer similar 5-year control rates, with low severe GU and GI toxicity rates of 4%-8% and <2%, respectively. Cryotherapy and high-intensity focused ultrasound (HIFU) offer similar 5-year RFS rates but carry significant risks for severe GU and GI toxicity in the range of 10%-27% and <2%, respectively. Early results of partial-gland salvage techniques in selected patients appear promising, with 3-year RFS rates of 48%-72% and rare grade 3 toxicity. CONCLUSION: It is important to understand the relative effectiveness and risks of the various treatment options to effectively counsel patients who face this distressing clinical situation. Whole-gland salvage options offer the possibility of long-term control but with significant risks of severe toxicity. Emerging data for the partial-gland salvage options in appropriately selected patients may offer hope of reasonable control rates with reduced severe toxicity.

Palliative care utilization and racial and ethnic disparities among women with de novo metastatic breast cancer in the United States.

PURPOSE: The potential disparities in palliative care delivery for underrepresented minorities with breast cancer are not well known. We sought to determine whether race and ethnicity impact the receipt of palliative care for patients with metastatic breast cancer (MBC). METHODS: We retrospectively reviewed the National Cancer Database for female patients diagnosed with stage IV breast cancer between 2010 and 2017 who received palliative care following diagnosis of MBC to assess the proportion of patients who received palliative care, including non-curative-intent local-regional or systemic therapy. Multivariable logistic regression analysis was performed to identify variables associated with receiving palliative care. RESULTS: 60,685 patients were diagnosed with de novo MBC. Of these, only 21.4% (n = 12,963) received a palliative care service. Overall, there was a positive trend in palliative care receipt from 18.2% in 2010 to 23.0% in 2017 (P < 0.001), which persisted when stratified by race and ethnicity. Relative to non-Hispanic White women, Asian/Pacific Islander women (aOR 0.80, 95% CI 0.71-0.90, P < 0.001), Hispanic women (adjusted odds ratio [aOR] 0.69, 95% CI 0.63-0.76, P < 0.001), and non-Hispanic Black women (aOR 0.94, 95% CI 0.88-0.99, P = 0.03) were less likely to receive palliative care. CONCLUSIONS: Fewer than 25% of women with MBC received palliative care between 2010 and 2017. While palliative care has significantly increased for all racial/ethnic groups, Hispanic White, Black, and Asian/Pacific Islander women with MBC still receive significantly less palliative care than non-Hispanic White women. Further research is needed to identify the socioeconomic and cultural barriers to palliative care utilization.

Heterogeneity in Radiotherapeutic Parameter Assumptions in Cost-Effectiveness Analyses in Prostate Cancer: A Call for Uniformity.

OBJECTIVES: Cost-effectiveness analyses (CEAs) may provide useful data to inform management decisions depending on the robustness of a model's input parameters. We sought to determine the level of heterogeneity in health state utility values, transition probabilities, and cost estimates across published CEAs assessing primarily radiotherapeutic management strategies in prostate cancer. METHODS: We conducted a systematic review of prostate cancer CEAs indexed in MEDLINE between 2000 and 2018 comparing accepted treatment modalities across all cancer stages. Search terms included "cost effectiveness prostate," "prostate cancer cost model," "cost utility prostate," and "Markov AND prostate AND (cancer OR adenocarcinoma)." Included studies were agreed upon. A Markov model was designed using the parameter estimates from the systematic review to evaluate the effect of estimate heterogeneity on strategy cost acceptability. RESULTS: Of 199 abstracts identified, 47 publications were reviewed and 37 were included; 508 model estimates were compared. Estimates varied widely across variables, including gastrointestinal toxicity risk (0%-49.5%), utility of metastatic disease (0.25-0.855), intensity-modulated radiotherapy cost ($21 193-$61 996), and recurrence after external-beam radiotherapy (1.5%-59%). Multiple studies assumed that different radiotherapy modalities delivering the same dose yielded varying cancer control rates. When using base estimates for similar parameters from included studies, the designed model resulted in 3 separate acceptability determinations. CONCLUSIONS: Significant heterogeneity exists across parameter estimates used to perform CEAs evaluating treatment for prostate cancer. Heterogeneity across model inputs yields variable conclusions with respect to the favorability and cost-effectiveness of treatment options. Decision makers are cautioned to review estimates in CEAs to ensure they are up to date and relevant to setting and population.

Five- and seven-year outcomes for image-guided moderately accelerated hypofractionated proton therapy for prostate cancer.

BACKGROUND: To report 5- and 7-year outcomes after image-guided moderately accelerated hypofractionated proton therapy (AHPT) for prostate cancer. MATERIAL AND METHODS: We reviewed the first 582 prostate cancer patients enrolled on prospective outcomes tracking trial and treated with double-scattered moderately AHPT between 2008 and 2015. 269 patients had low-risk (LR) and 313 had intermediate-risk (IR) disease, including 149 with favorable intermediate-risk (FIR) and 164 with unfavorable intermediate-risk (UIR) disease. LR patients received a median 70.0GyRBE (2.5GyRBE/fraction) and IR patients received a median of 72.5 GyRBE. Seventeen patients (UIR, n = 12) received androgen deprivation therapy (ADT) for a median of 6 months. Toxicities were graded per the CTCAE, v4.0, and patient-reported quality-of-life data were reviewed. RESULTS: Median follow-up was 8.0 years (0.9-12.2). The 5- and 7-year rates of freedom from biochemical progression (FFBP) overall and in the LR and IR subsets, respectively, were 96.8/95.2%, 98.8/98.8%, and 95.0/91.9%. For the FIR and UIR subsets, they were 97.2/95.2% and 93.1/88.8%. Actuarial 5- and 7-year rates of late CTCAE, v4.0, grade 2 gastrointestinal (GI), grade 3 GI, and grade 3 genitourinary (GU) toxicities were 9.9%/11.2%, 1.4/1.4% and 1.3/2.1%, respectively. No grade ≥4 GI or GU toxicities occurred. The mean (standard deviation, SD) IPSS and EPIC Composite bowel function and bother scores were 7 (SD = 5), 97 (SD = 7), and 94 (SD = 6), respectively at baseline, 7 (SD = 5), 92 (SD = 13), and 92 (SD = 9) at the 5-year follow-up, and 7 (SD = 5), 93 (SD = 12), and 92 (SD = 10) at the 7-year follow-up. CONCLUSION: Image-guided AHPT 5- and 7-year outcomes show high efficacy, minimal physician-assessed toxicity, and excellent patient-reported outcomes in this cohort.

RBE-weighted dose and its impact on the risk of acute coronary event for breast cancer patients treated with intensity modulated proton therapy.

PURPOSE: To evaluate the relative biological effectiveness (RBE)-weighted dose to the heart and to estimate RBE uncertainties when assuming a constant RBE of 1.1, for breast cancer patients receiving intensity-modulated proton therapy (IMPT). Further, to study the impact of RBE uncertainties on the risk of an acute coronary event (ACE). MATERIAL AND METHODS: We analyzed 20 patients who received IMPT to either the left breast (n = 10) or left chest wall (n = 10) and regional lymph nodes. The Monte Carlo simulation engine, MCsquare, was used to simulate the dose-averaged linear energy transfer (LETd) map. The RBE-weighted dose to the heart and its substructures was calculated using three different RBE models. The risk of ACE was estimated per its linear relationship with mean heart dose (MHD) as established by Darby et al. RESULTS: The median MHD increased from 1.33 GyRBE assuming an RBE of 1.1 to 1.64, 1.87, and 1.99 GyRBE when using the RBE-weighted dose models. The median values (and ranges) of the excess absolute risk of ACE were 0.4% (0.1%-0.8%) when assuming an RBE of 1.1, and 0.6% (0.2%-1.0%), 0.6% (0.2%-1.1%), and 0.7% (0.2%-1.1%) with the RBE-weighted models. For our patient cohort, the maximum excess absolute risk of ACE increased by 0.3% with the RBE-weighted doses compared to the constant RBE of 1.1, reaching an excess absolute ACE risk of 1.1%. The interpatient LETd variation was small for the relevant high-dose regions of the heart. CONCLUSION: All three RBE models predicted a higher biological dose compared to the clinical standard dose assuming a constant RBE of 1.1. An underestimation of the biological dose results in underestimation of the ACE risk. Analyzing the voxel-by-voxel biological dose and the LET map alongside clinical outcomes is warranted in the development of a more accurate normal-tissue complication probability model.

Intraoperative radiation therapy for early-stage breast cancer: a single-institution experience.

Background: To assess outcomes and toxicity after low-energy intraoperative radiotherapy (IORT) for early-stage breast cancer (ESBC). Materials and methods: We reviewed patients with unilateral ESBC treated with breast-conserving surgery and 50-kV IORT at our institution. Patients were prescribed 20 Gy to the surface of the spherical applicator, fitted to the surgical cavity during surgery. Patients who did not meet institutional guidelines for IORT alone on final pathology were recommended adjuvant treatment, including additional surgery and/or external-beam radiation therapy (EBRT). We analyzed ipsilateral breast tumor recurrence, overall survival, recurrence-free survival and toxicity. Results: Among 201 patients (median follow-up, 5.1 years; median age, 67 years), 88% were Her2 negative and ER positive and/or PR positive, 98% had invasive ductal carcinoma, 87% had grade 1 or 2, and 95% had clinical T1 disease. Most had pathological stage T1 (93%) N0 (95%) disease. Mean IORT applicator dose at 1-cm depth was 6.3 Gy. Post-IORT treatment included additional surgery, 10%; EBRT, 11%; adjuvant chemotherapy, 9%; and adjuvant hormonal therapy, 74%. Median total EBRT dose was 42.4 (range, 40.05-63) Gy and median dose per fraction was 2.65 Gy. At 5 years, the cumulative incidence of ipsilateral breast tumor recurrence was 2.7%, the overall survival rate was 95% with no breast cancer-related deaths, and the recurrence-free survival rate was 96%. For patients who were deemed unsuitable for postoperative IORT alone and did not receive recommended risk-adapted EBRT, the IBTR rate was 4.7% versus 1.7% (p = 0.23) for patients who were either suitable for IORT alone or unsuitable and received adjuvant EBRT. Cosmetic toxicity data was available for 83%, with 7% experiencing grade 3 breast toxicity and no grade 4-5 toxicity. Conclusions: IORT for select patients with ESBC results in acceptable outcomes in regard to ipsilateral breast tumor recurrence and toxicity.

Five-Year Breast Surgeon Experience in LYMPHA at Time of ALND for Treatment of Clinical T1-4N1-3M0 Breast Cancer.

BACKGROUND: Breast cancer-related lymphedema (BCRL) is a source of postoperative morbidity for breast cancer survivors. Lymphatic microsurgical preventive healing approach (LYMPHA) is a technique used to prevent BCRL at the time of axillary lymph node dissection (ALND). We report the 5-year experience of a breast surgeon trained in LYMPHA and investigate the outcomes of patients who underwent LYMPHA following ALND for treatment of cT1-4N1-3M0 breast cancer. METHODS: A retrospective review of patients with cT1-4N1-3M0 breast cancer was performed in patients who underwent ALND with and without LYMPHA. Diagnosis of BCRL was made by certified lymphedema therapists. Descriptive statistics and lymphedema surveillance data were analyzed using results of Fisher's exact or Wilcoxon rank-sum tests. Logistic regression and propensity matching were performed to assess the reduction of BCRL occurrence following LYMPHA. RESULTS: In a 5-year period, 132 patients met inclusion criteria with 76 patients undergoing LYMPHA at the time of ALND and 56 patients undergoing ALND alone. Patients who underwent LYMPHA at the time of ALND were significantly less likely to develop BCRL than those who underwent ALND alone (p = 0.045). Risk factors associated with BCRL development were increased patient age (p = 0.007), body mass index (BMI) (p = 0.003), and, in patients undergoing LYMPHA, number of positive nodes (p = 0.026). CONCLUSIONS: LYMPHA may be successfully employed by breast surgeons trained in lymphatic-venous anastomosis at the time of ALND. While research efforts should continue to focus on prevention and surveillance of BCRL, LYMPHA remains an option to reduce BCRL and improve patient quality of life.

Incorporation of the LETd-weighted biological dose in the evaluation of breast intensity-modulated proton therapy plans.

PURPOSE: To evaluate the LETd-weighted biological dose to OARs in proton therapy for breast cancer and to study the relationship of the LETd-weighted biological dose relative to the standard dose (RBE = 1.1) and thereby to provide estimations of the biological dose uncertainties with the standard dose calculations (RBE = 1.1) commonly used in clinical practice. METHOD: This study included 20 patients who received IMPT treatment to the whole breast/chest wall and regional lymph nodes. The LETd distributions were calculated along with the physical dose using an open-source Monte Carlo simulation package, MCsquare. Using the McMahon linear model, the LETd-weighted biological dose was computed from the physical dose and LETd. OAR doses were compared between the Dose (RBE = 1.1) and the LETd-weighted biological dose, on brachial plexus, rib, heart, esophagus, and Ipsilateral lung. RESULTS: On average, the LETd-weighted biological dose compared to the Dose (RBE = 1.1) was higher by 8% for the brachial plexus D0.1 cc, 13% for the ribs D0.5 cc, 24% for mean heart dose, and 10% for the esophagus D0.1 cc, respectively. The LETd-weighted doses to the Ipsilateral lung V5, V10, and V20 were comparable to the Dose (RBE = 1.1). No statistically significant difference in biological dose enhancement to OARs was observed between the intact breast group and the CW group, with the exception of the ribs: the CW group experienced slightly greater biological dose enhancement (13% vs. 12%, p = 0.04) to the ribs than the intact breast group. CONCLUSION: Enhanced biological dose was observed compared to standard dose with assumed RBE of 1.1 for the heart, ribs, esophagus, and brachial plexus in breast/CW and regional nodal IMPT plans. Variable RBE models should be considered in the evaluation of the IMPT breast plans, especially for OARs located near the end of range of a proton beam. Clinical outcome studies are needed to validate model predictions for clinical toxicities.

Novel Radiotherapy Techniques for Breast Cancer.

During the early decades of radiation therapy for breast cancer, local control of disease was documented consistently but, enigmatically, an anticipated impact on breast cancer survival was not observed, leading to confusion in our understanding of the natural history of breast cancer and radiation effects. Now, almost 90 years after its first use in breast cancer, technology developments in diagnostic imaging and radiation therapy have elucidated parts of this enigma. The data now available demonstrate a significant impact of radiation therapy on survival as well as disease control and treatment-related mortality, opening a doorway to understanding the powerful impact of radiation therapy on both breast cancer and critical organs. Efforts are focused on leveraging novel techniques to maximize the benefits of radiation for breast cancer patients.

Serum Testosterone 60 Months after Passive-Scatter Proton Therapy for Localized Prostate Cancer.

Studies demonstrate a decline of ∼10% in serum testosterone (ST) level after X-ray radiotherapy for prostate cancer. We evaluated changes in ST for patients with low- and intermediate-risk prostate cancer receiving 70-82Gy(RBE) using passive-scatter proton therapy (PT). ST was checked at baseline (n = 358) and at 60+ months after PT (n = 166). The median baseline ST was 363.3 ng/dl (range, 82.0-974.0). The median ST 5 years after PT was 391.5 ng/dl (range, 108.0-1061.0). The difference was not statistically significant (p = 0.9341). Passive-scatter PT was not associated with testosterone suppression at 5 years, suggesting that protons may cause less out-of-field scatter radiation than X-rays.

A comprehensive dosimetric study of Monte Carlo and pencil-beam algorithms on intensity-modulated proton therapy for breast cancer.

PB algorithms are commonly used for proton therapy. Previously reported limitations of the PB algorithm for proton therapy are mainly focused on high-density gradients and small-field dosimetry, the effect of PB algorithms on intensity-modulated proton therapy (IMPT) for breast cancer has yet to be illuminated. In this study, we examined 20 patients with breast cancer and systematically investigated the dosimetric impact of MC and PB algorithms on IMPT. Four plans were generated for each patient: (a) a PB plan that optimized and computed the final dose using a PB algorithm; (b) a MC-recomputed plan that recomputed the final dose of the PB plan using a MC algorithm; (c) a MC-renormalized plan that renormalized the MC-recomputed plan to restore the target coverage; and (d) a MC-optimized plan that optimized and computed the final dose using a MC algorithm. The DVH on CTVs and on organ-at-risks (OARs) from each plan were studied. The Mann-Whitney U-test was used for testing the differences between any two types of plans. We found that PB algorithms significantly overestimated the target dose in breast IMPT plans. The median value of the CTV D99% , D95% , and Dmean dropped by 3.7%, 3.4%, and 2.1%, respectively, of the prescription dose in the MC-recomputed plans compared with the PB plans. The magnitude of the target dose overestimation by the PB algorithm was higher for the breast CTV than for the chest wall CTV. In the MC-renormalized plans, the target dose coverage was comparable with the original PB plans, but renormalization led to a significant increase in target hot spots as well as skin dose. The MC-optimized plans led to sufficient target dose coverage, acceptable target hot spots, and good sparing of skin and other OARs. Utilizing the MC algorithm for both plan optimization and final dose computation in breast IMPT treatment planning is therefore desirable.

Radiotherapy for Orbital Pseudotumor: The University of Florida Experience.

BACKGROUND: To evaluate outcomes after definitive radiotherapy for orbital pseudotumor. METHODS: We reviewed adult patients treated between 1971 and 2012. RESULTS: 20 patients with 8.0-year median follow-up were analyzed. Symptoms improved in 75% of patients: 40% showed a complete response, 35% partial response, and 20% had stable disease. The disease progressed in 1 and recurred in 8 patients. Local control rates were 63% and 53% at 5 and 10 years, respectively. The most common toxicities were cataracts (10%) and dry eye (10%). CONCLUSIONS: Radiotherapy for orbital pseudotumor is well-tolerated and results in long-term control in most patients, with local control in over half.

Long-term outcomes following proton therapy for prostate cancer in young men with a focus on sexual health.

BACKGROUND: We investigated long-term outcomes for men ≤60 years old treated with proton therapy (PT). METHODS: Of 254 men ≤60 years old were treated with proton therapy alone for prostate cancer. Risk stratification included 56% with low-, 42% with intermediate- and 2% with high-risk disease. Patients received 76-82 Gy at 2 Gy/fraction or 70-72.5 Gy at 2.5 Gy/fraction. Before treatment and every 6-12 months for 5 years, patients were evaluated by a physician, answered health-related quality of life surveys, including the EPIC, IIEF and IPSS, and had PSA evaluated. RESULTS: Median follow-up for the cohort was 7.1 years; 7-year biochemical-free survival was 97.8%. Eight men (one high-risk; five intermediate-risk and two low-risk) experienced biochemical progression, including one who died of disease 9 years after treatment. Potency (erections firm enough for sexual intercourse) was 90% at baseline and declined to 72% at the first-year follow-up, but declined to only 67% at 5 years. Only 2% of patients developed urinary incontinence requiring pads. The bowel habits mean score declined from a baseline of 96 to 88 at 1 year, which improved over the following years to 93 at 5 years. CONCLUSIONS: Young men with prostate cancer continue to have excellent results with respect to 7-year biochemical control and 5-year erectile function, without clinically significant urinary incontinence 5 years after proton therapy. Comparative effectiveness studies of proton therapy with surgery and IMRT are needed.

Outcomes following proton therapy for pediatric ependymoma.

BACKGROUND: Proton therapy can reduce the low and intermediate radiation dose to uninvolved brain tissue in children with intracranial ependymomas, which may improve functional outcomes and reduce second malignancies in survivors. Accordingly, ependymoma has become the most common pediatric tumor treated with proton therapy, yet data on efficacy and toxicity are limited. MATERIAL AND METHODS: Between June 2007 and February 2017, 179 children (≤21 years old) with nonmetastatic grade II/III intracranial ependymoma received proton therapy at our institution. Median age, 3.5 years (range, 0.7-21); 58% were male. Most (66%) tumors were in the posterior fossa and classified as WHO grade III (67%). 27% underwent multiple operations to maximize the extent of resection; ultimately 85% had a gross total or near total tumor resection before radiotherapy. 33% received preradiation chemotherapy. Median radiation dose in children ≤3 years old, 54 Gy(RBE). Most (>90%) children over 3 years old received 59.4 Gy(RBE). Patient and treatment variables were assessed for correlation with disease control. RESULTS: Median follow-up, 3.2 years. 3-year local control, progression-free survival, and overall survival rates were 85%, 76%, and 90%, respectively. First site of progression was local, metastatic, or simultaneous in 14, 17 and 6 patients, respectively. On multivariate analysis, subtotal resection was associated with inferior local control (67% vs. 88%; p ≤ .01) and progression-free survival (59% vs. 79%; p < .05). Male sex was associated with inferior progression-free (67% vs. 87%; p< .05) and overall survival (84% vs. 99%; p < .01). The 3-year CTCAE grade 2 + brainstem toxicity rate was 5.5% (95% CI: 2.9-10.2), including 1 grade 5 toxicity. CONCLUSIONS: This series of proton therapy for pediatric intracranial ependymoma demonstrates disease control comparable to photon series without unexpected toxicity. Subtotal resection and male sex were associated with inferior disease control. Additional follow-up to quantify the expected reductions in late toxicity with proton therapy is ongoing.

Five-year outcomes from a prospective trial of image-guided accelerated hypofractionated proton therapy for prostate cancer.

PURPOSE: To report 5-year outcomes of a prospective trial of image-guided accelerated hypofractionated proton therapy (AHPT) for prostate cancer. PATIENTS AND METHODS: 215 prostate cancer patients accrued to a prospective institutional review board-approved trial of 70Gy(RBE) in 28 fractions for low-risk disease (n = 120) and 72.5Gy(RBE) in 29 fractions for intermediate-risk disease (n = 95). This trial excluded patients with prostate volumes of ≥60 cm3 or International Prostate Symptom Scores (IPSS) of ≥15, patients on anticoagulants or alpha-blockers, and patients in whom dose-constraint goals for organs at risk (OAR) could not be met. Toxicities were graded prospectively according to Common Terminology Criteria for Adverse Events (CTCAE), version 3.0. This trial can be found on ClinicalTrials.gov (NCT00693238). RESULTS: Median follow-up was 5.2 years. Five-year rates of freedom from biochemical and clinical disease progression were 95.9%, 98.3%, and 92.7% in the overall group and the low- and intermediate-risk subsets, respectively. Actuarial 5-year rates of late radiation-related CTCAE v3.0 grade 3 or higher gastrointestinal and urologic toxicities were 0.5% and 1.7%, respectively. Median IPSS before treatment and at 4+ years after treatment were 6 and 5 for low-risk patients and 4 and 6 for intermediate-risk patients. CONCLUSIONS: Image-guided AHPT 5-year outcomes show high efficacy and minimal physician-assessed toxicity in selected patients. These results are comparable to the 5-year results of our prospective trials of standard fractionated proton therapy for patients with low-risk and intermediate-risk prostate cancer. Longer follow-up and a larger cohort are necessary to confirm these findings.

Biological dose and complication probabilities for the rectum and bladder based on linear energy transfer distributions in spot scanning proton therapy of prostate cancer.

BACKGROUND: The increased linear energy transfer (LET) at the end of the Bragg peak causes concern for an elevated and spatially varying relative biological effectiveness (RBE) of proton therapy (PT), often in or close to dose-limiting normal tissues. In this study, we investigated dose-averaged LET (LETd) distributions for spot scanning PT of prostate cancer patients using different beam angle configurations. In addition, we derived RBE-weighted (RBEw) dose distributions and related normal tissue complication probabilities (NTCPs) for the rectum and bladder. MATERIAL AND METHODS: A total of 21 spot scanning proton plans were created for each of six patients using a prescription dose of 78 Gy(RBE1.1), with each plan using two 'mirrored' beams with gantry angles from 110°/250° to 70°/290°, in steps of 2°. Physical dose and LETd distributions were calculated as well as RBEw dose distributions using either RBE = 1.1 or three different variable RBE models. The resulting biological dose distributions were used as input to NTCP models for the rectum and bladder. RESULTS: For anterior oblique (AO) configurations, the rectum LETd volume and RBEw dose increased with increasing angles off the lateral opposing axis, with the RBEw rectum dose being higher than for all posterior oblique (PO) configurations. For PO configurations, the corresponding trend was seen for the bladder. Using variable RBE models, the rectum NTCPs were highest for the AO configurations with up to 3% for the 80°/280° configuration while the bladder NTCPs were highest for the PO configurations with up to 32% for the 100°/260°. The rectum D1cm3 constraint was fulfilled for most patients/configurations when using uniform RBE but not for any patient/configuration with variable RBE models. CONCLUSIONS: Compared to using constant RBE, the variable RBE models predicted increased biological doses to the rectum, bladder and prostate, which in turn lead to substantially higher estimated rectum and bladder NTCPs.

Sperm preservation and neutron contamination following proton therapy for prostate cancer study.

BACKGROUND: The present study investigates the impact of scatter dose radiation to the testis on ejaculate and sperm counts from treatment of prostate cancer with passive-scatter proton therapy. MATERIAL AND METHODS: From March 2010 to November 2014, 20 men with low- or intermediate-risk prostate cancer enrolled in an IRB-approved protocol and provided a semen sample prior to passive-scatter proton therapy and 6-12 months following treatment. Men were excluded if they had high-risk prostate cancer, received androgen deprivation therapy, were on alpha blockers (due to retrograde ejaculation) prior to treatment, had baseline sperm count <1 million, or were unable to produce a pre-treatment sample or could not provide a follow-up specimen. Sperm counts of 0 were considered azoospermia and <15 million/ml were classified as oligospermia. RESULTS: Four patients were unable to provide a sufficient quantity of semen for analysis. Among the 16 remaining patients, only one was found to have oligospermia (7 million/ml). There was a statistically significant reduction in semen volume (median, 0.5 ml) and increase in pH (median 0.5). Although not statistically significant, there appeared to be a decline in sperm concentration (median, 16 million/ml), total sperm count (median, 98.5 million), normal morphology (median, 9%), and rapid progressive motility (median, 9.5%). DISCUSSION: Men did not have azoospermia 6-12 months following passive-scatter proton therapy indicating minimal scatter radiation to the testis during treatment. Changes in semen quantity and consistency may occur due to prostate irradiation, which could impact future fertility and/or sexual activity.

Proton Therapy for Pediatric Hodgkin Lymphoma.

BACKGROUND: Compared to X-ray radiation therapy, proton therapy (PT) reduces the radiation dose to organs at risk, which is expected to translate into fewer second cancers and less cardiac morbidity decades after treatment. The Children's Oncology Group high-risk pediatric Hodgkin lymphoma (PHL) protocol, AHOD1331, allows the use of PT, yet limited data exist on the use of PT in PHL. PROCEDURE: Between 2010 and 2014, 22 pediatric patients were treated with PT for PHL at our institution: 7 intermediate-risk patients, 11 high-risk patients, and 4 relapsed patients. The patients' age ranged from 6 to 18 years old. Median follow-up was 36 months. All patients received chemotherapy before PT. RESULTS: The 2-year and 3-year overall survival rates were both 94%, and the progression-free survival rate was 86%. Recurrences occurred in three high-risk patients: one isolated in-field cervical lymph node and two in-field and out-of-field. All recurrences occurred within 5 months of completing PT. No PT-related grade 3 or higher acute or late complications were observed. CONCLUSION: PT for PHL showed no short-term severe toxicity and yields similar short-term control to recently published large multi-institutional clinical trials.