The role of dose escalation and proton therapy in perioperative or definitive treatment of chondrosarcoma and chordoma: An analysis of the National Cancer Data Base.

BACKGROUND: Chordomas and chondrosarcomas are a rare but challenging subset of tumors to treat; however, previous studies have shown benefits from proton therapy, which are thought to be primarily driven by prescription conformality permitting homogeneous tumor dosing and the allowance of higher doses. No retrospective studies to date have directly compared the outcomes of conventional and particle therapy or examined the role of high doses (specifically ≥70 Gy) in definitive radiotherapy (DRT) or perioperative radiotherapy (PRT) for both types of malignancies. METHODS: A total of 863 patients with chondrosarcoma and 715 patients with chordoma treated with nonpalliative proton or conventional radiation therapy with a dose range of 20 to 80 Gy and at least 15 months of follow-up were identified from the National Cancer Data Base for the years 2003-2014. The primary endpoint of overall survival (OS) was evaluated, and clinical features, including age, sex, grade, clinical stage, and Charlson-Deyo comorbidity index, were compared. RESULTS: Patients receiving DRT were older and had more advanced disease. In DRT for chondrosarcoma, a high dose (40.6% vs 16.9%; P = .006) and proton therapy (75.0% vs 19.1%; P = .046) were associated with improved OS at 5 years in a multivariate analysis. In DRT for chordoma, proton therapy was associated with improved OS at 5 years in a multivariate analysis (100% vs 34.1%; P = .031), and a high dose for chordoma was significant for improved OS in a univariate analysis with both DRT (79.0% vs 54.1%; P = .027) and PRT (83.3% vs 77.4%; P = .007). CONCLUSIONS: In the largest retrospective series to date, dose escalation and proton radiotherapy were associated with improved OS in patients with chondrosarcoma and chordoma despite limited follow-up and access to particle therapy.

Quality of Life after post-prostatectomy intensity modulated radiation therapy to the prostate bed with or without the use of gold fiducial markers for image guidance or higher total radiotherapy doses.

PURPOSE: To evaluate quality of life (QoL) after post-prostatectomy intensity modulated radiation therapy (IMRT) in the "adjuvant" setting starting within 4 months of radical prostatectomy for adverse features; and "salvage" setting for a PSA≥0.2ng/mL. MATERIALS AND METHODS: Retrospective review of 130 patients who underwent IMRT to the prostate bed±gold fiducial marker placement for image guidance to 64.8-72.0Gy (median, 70.2Gy) between 2004 and 2013. Higher doses were defined as 70.2-72.0Gy and lower doses were defined as 64.8-68.4Gy. Androgen deprivation therapy (ADT) was given to 4/48 (8%) adjuvant patients and 9/82 (11%) salvage patients. International Prostate Symptom Score (IPSS), Sexual Health Inventory for Men (SHIM), and Expanded Prostate Cancer Index Composite-26-bowel (EPIC-26-bowel) questionnaires were used to assess urinary, sexual, and bowel QoL, respectively. RESULTS: Median follow-up was 46 months. There were better urinary (p=0.03) and sexual (p=0.002) QoL scores with adjuvant IMRT relative to salvage IMRT. The use of prostate bed fiducial markers did not significantly affect urinary, sexual, or bowel QoL (p=0.39, p=0.49, and p=0.40, respectively). Higher total radiotherapy doses did not significantly affect urinary, sexual, or bowel QoL (p=0.21, p=0.61, and p=0.36, respectively). CONCLUSIONS: There was no significant change in urinary, sexual, and bowel sexual QoL with post-prostatectomy IMRT regardless of whether prostate bed fiducial markers or higher total radiotherapy doses were used. QoL with IMRT in the present study compares favorably with prior reports for three-dimensional conformal radiation therapy.

Having Medicaid insurance negatively impacts outcomes in patients with head and neck malignancies.

BACKGROUND: Patients covered by Medicaid insurance appear to have poorer cancer outcomes. Herein, the authors sought to test whether Medicaid was associated with worse outcomes among patients with head and neck cancer (HNC). METHODS: The records of 1698 patients with squamous cell HNC without distant metastatic disease were retrospectively reviewed from an institutional database between 1998 and 2011. At the time of diagnosis, insurance status was categorized as Medicaid, Medicare/other government insurance, or private insurance. Outcomes including locoregional control (LRC) and overall survival (OS) were estimated using the Kaplan-Meier method and Cox regression multivariate analysis (MVA). RESULTS: The median follow-up for all patients was 35 months. Medicaid patients comprised 11% of the population; the remaining patients were privately insured (56%) or had Medicare/government insurance (34%). On MVA, Medicaid patients were younger, were current smokers, had higher tumor T and N classifications, and experienced a longer time from diagnosis to treatment initiation (all P<.005). Medicaid insurance status was associated with a deficit of 13% in LRC (69% vs 82%) and 26% in OS (46% vs 72%) at 3 years (all with P<.001). A time from diagnosis to treatment initiation of >45 days was found to be associated with worse 3-year LRC (77% vs 83%; P = .009) and OS (68% vs 71%; P = .008). On MVA, Medicaid remained associated with a deficit in LRC (P = .002) and OS (P<.001). CONCLUSIONS: Patients with Medicaid insurance more often present with locally advanced HNC and experience a higher rate of treatment delays compared with non-Medicaid patients. Medicaid insurance status appears to be independently associated with deficits in LRC and OS. Improvements in the health care system, such as expediting treatment initiation, may improve the outcomes of patients with HNC. Cancer 2016;122:3529-3537. © 2016 American Cancer Society.

Management of Oropharyngeal Cancer in the HPV Era.

BACKGROUND: Historically, oropharyngeal cancer (OPC) has been attributed to risk factors such as smoking and alcohol use. The increased incidence of OPC has been driven by human papillomavirus (HPV) infection. METHODS: A search of the literature involving HPV infection and OPC was performed, along with a search of ongoing clinical trials regarding HPV-positive OPC. RESULTS: This review summarizes the differences in epidemiology and prognosis of HPV-positive OPC compared with non-HPV-related OPC. It will also discuss use of de-escalating treatment to minimize toxicity while maintaining excellent outcomes. Disease management is also addressed, including prevention and follow-up recommendations for this cohort of patients. CONCLUSIONS: HPV-positive OPC is a distinct disease, and efforts should be made to personalize its management. Preventive measures and vaccinations, along with de-escalation of treatment, may help optimize outcomes in this population.

Fractionated stereotactic radiotherapy to the post-operative cavity for radioresistant and radiosensitive brain metastases.

Following surgical resection for brain metastases, fractionated stereotactic radiotherapy (FSRT) has been used as an alternative to single dose treatment for large cavities and to reduce risks of late toxicity. The purpose of this study was to evaluate the outcomes of patients treated with FSRT to the post-operative bed for both radioresistant and radiosensitive brain metastases. Between December 2009 and May 2013 a total of 65 patients with newly diagnosed brain metastases were treated with resection followed by FSRT. Patients were treated to a total dose of 20-30 Gy in five fractions. Median planning target volume (PTV) was 16.88 cm(3) (range 4.87-128.43 cm(3)). The median follow-up for all patients was 8.5 months (range 1.1-28.6 months) with a median of 12.9 months for living patients. One and two year Kaplan-Meier estimates of local control were 87.0 and 70.0 %, respectively. Local control at 1 year was 85.6 and 88.0% for radioresistant and radiosensitive tumors, respectively (p = 0.44). A PTV ≥17 cm(3), was associated with local failure, HR 8.63 ((1.44-164.78); p = 0.02). One and two year distant control rates were 50.9 and 46.2%, respectively with six patients (9.2%) experiencing leptomeningeal disease. OS rates at 1 and 2 years were 65.2 and 47.5%, respectively. Survival was significantly associated with recursive partitioning analysis class (p = 0.001) and graded prognostic assessment score (p = 0.005). One case of radionecrosis was noted on follow-up imaging. FSRT in five fractions offers excellent local control in both radiosensitive and radioresistant tumors with minimal toxicity.

Stage I seminoma: treatment outcome at King Hussein Cancer Center in Jordan.

BACKGROUND: The aim of this report is to address treatment outcomes of patients with early-stage seminoma in a single institution with special reference to patients with history of surgical violation of the scrotum. METHODS: Seventy four patients with pure seminoma were treated at King Hussein Cancer Center (Amman, Jordan) between 2003 and 2010. All patients underwent orchiectomy. All but 3 patients received adjuvant radiotherapy. Patients who underwent surgical violation of the scrotum prior to referral were managed by further excision or irradiation of the scrotal scar. The follow-up ranged from 1 to 200 months (mean, 33 months). RESULTS: At the time of follow-up; all but one patient remain alive. The 3-year relapse-free survival for the entire cohort was 95.9%. Three patients developed relapse, all of whom received adjuvant irradiation following inguinal orchiectomy and initially harbored tumors larger than 4 cm upon pathological examination. Median time to relapse was 14 months (range, 8-25 months). None were associated with elevated tumor markers prior to detection of relapse. All but one patient were successfully salvaged by chemotherapy. CONCLUSIONS: Our results confirm the excellent prognosis of patients with early-stage seminoma treated by orchiectomy and adjuvant radiotherapy in a developing country. Although all patients who developed relapse demonstrated adverse pathological findings upon initial assessment, no consistent predictor of relapse was found. Scrotal scar re-excision or irradiation in patients with prior history of surgical violation of the scrotum are effective measures in preventing local failure.

Analysis of Relapse Events After Definitive Chemoradiotherapy in Locally Advanced Non-Small-Cell Lung Cancer Patients.

BACKGROUND: The appropriate follow-up frequency after definitive chemoradiotherapy (CRT) for locally advanced non-small-cell lung cancer patients is unknown. Although surveillance guidelines have been proposed, very few data support current recommendations. Here we analyze relapse events after CRT and investigate whether symptomatic relapses versus those detected by surveillance imaging influences outcomes. PATIENTS AND METHODS: Stage III non-small-cell lung cancer patients treated with CRT at our institution between 2005 and 2014 were retrospectively analyzed. Relapse events were grouped into posttreatment intervals and analyzed with cumulative tables. Time to relapse and overall survival (OS) were compared between patients with relapse detection via symptomatic presentation versus surveillance imaging. RESULTS: A total of 211 patients were identified for analysis. The median follow-up was 43 months for patients alive at the time of analysis. The median age was 63 years, and equal proportions had IIIA or IIIB disease. A total of 135 patients (64%) experienced disease relapse, and of these, 74% did so within 12 months. In those who did not experience relapse at ≤ 12 months, 16%, 6%, and < 5% experienced relapse during 12 to 24, 24 to 36, and > 36 months of follow-up, respectively. In patients with relapse, 56% presented symptomatically, which led to inferior median OS compared to those identified by surveillance imaging (23 vs. 36 months; P = .013). CONCLUSION: This study identified that most relapses occur within 1 year of completing CRT, and approximately half of these occur within 6 months. A symptomatic relapse led to inferior OS. More aggressive surveillance imaging may therefore identify asymptomatic relapses that are amenable to earlier salvage therapy.

Kinetic analysis of contralateral liver hypertrophy after radioembolization of primary and metastatic liver tumors.

BACKGROUND: Radioembolization induces liver hypertrophy, although the extent and rate of hypertrophy are unknown. Our goal was to examine the kinetics of contralateral liver hypertrophy after transarterial radioembolization. METHODS: A retrospective study (2010-2014) of treatment-naïve patients with primary/secondary liver malignancies undergoing right lobe radioembolization was performed. Computed tomography volumetry was performed before and 1, 3, and 6 months after radioembolization. Outcomes of interest were left lobe (standardized future liver remnant) degree of hypertrophy, kinetic growth rate, and ability to reach goal standardized future liver remnant ≥40%. Medians were compared with the Kruskall-Wallis test. Time to event analysis was used to estimate time to reach goal standardized future liver remnant. RESULTS: In the study, 25 patients were included. At 1, 3, and 6 months, median degree of hypertrophy was 4%, 8%, and 12% (P < .001), degree of hypertrophy relative to baseline future liver remnants was 11%, 17%, and 31% (P = .015), and kinetic growth rate was 0.8%, 0.5%, and 0.4%/week (P = .002). In patients with baseline standardized future liver remnant <40% (N= 16), median time to reach standardized future liver remnant ≥40% was 7.3 months, with 75% accomplishing standardized future liver remnant ≥40% at 8.2 months. CONCLUSION: Radioembolization induces hypertrophy of the contralateral lobe to a similar extent as existing methods, although at a lower rate. The role of radioembolization as a dual therapy (neoadjuvant and hypetrophy-inducing) for selected patients needs to be studied. (Surgery 2017;160:XXX-XXX.).

Using the Albumin-Bilirubin (ALBI) grade as a prognostic marker for radioembolization of hepatocellular carcinoma.

BACKGROUND: The Child-Pugh (CP) class is a commonly used scoring system to measure liver function in patients with hepatocellular carcinoma (HCC). We correlate the Albumin-Bilirubin (ALBI) grading system and CP to overall survival in our HCC patients receiving radioembolization. METHODS: We retrospectively evaluated patients who received radioembolization for HCC between the years 2009-2014. We evaluated the albumin and bilirubin levels in our patients prior to receiving their first (n=124) radioembolization. The ALBI grades were calculated from these data with the formula (log10 bilirubin ×0.66) + (albumin × -0.085) and correlated to outcomes using Mantel-Cox Log analysis. These statistical comparisons were duplicated with CP classes. RESULTS: Median survival differences between CP class A and B and between ALBI grade 1 and 2 were 4.7 and 9.9 months, respectively. A subset of ALBI grades 1 and 2 were identified within our CP class A patients with a median survival difference of 9.9 months. CONCLUSIONS: ALBI is a more sensitive marker of liver function than CP in the setting of mild dysfunction. Using ALBI, we identified a subset of patients that have significantly better outcomes from Y-90 radioembolization than previously identified with CP.

Quantitatively Excessive Normal Tissue Toxicity and Poor Target Coverage in Postoperative Lung Cancer Radiotherapy Meta-analysis.

BACKGROUND: A previous meta-analysis (MA) found postoperative radiotherapy (PORT) in lung cancer patients to be detrimental in N0/N1 patients and equivocal in the N2 setting. We hypothesized that treatment plans generated using MA protocols had worse dosimetric outcomes compared to modern plans. PATIENTS AND METHODS: We retrieved plans for 13 patients who received PORT with modern planning. A plan was recreated for each patient using the 8 protocols included in MA. Dosimetric values were then compared between the modern and simulated MA plans. RESULTS: A total of 104 MA plans were generated. Median prescribed dose was 50.4 (range, 50-60) Gy in the modern plans and 53.2 (30-60) Gy in the MA protocols. Median planning volume coverage was 96% (93%-100%) in the modern plans, versus 58% (0%-100%) in the MA plans (P < .001). Internal target volume coverage was 100% (99%-100%) versus 65% (0%-100%), respectively (P < .001). Organs at risk received the following doses: spinal cord maximum dose, 36.8 (4.6-50.4) Gy versus 46.8 (2.9-74.0) Gy (P < .001); esophageal mean dose, 22.9 (5.5-35) Gy versus 30.5 (11.1-52.5) Gy (P = .003); heart V30 (percentage of volume of an organ receiving at least a dose of 30 Gy), 16% (0%-45%) versus 35% (0%-79%) (P = .047); mean lung dose, 12.4 (3.4-24.3) Gy versus 14.8 (4.1-27.4) Gy (P = .008); and lung V20, 18% (4%-34%) versus 25% (8%-67%) (P = .023). CONCLUSION: We quantitatively confirm the inferiority of the techniques used in the PORT MA. Our analysis showed a lower therapeutic ratio in the MA plans, which may explain the poor outcomes in the MA. The findings of the MA are not relevant in the era of modern treatment planning.

Viral hepatitis associated hepatocellular carcinoma outcomes with yttrium-90 radioembolization.

BACKGROUND: Viral associated (VA) malignancies have recently been correlated with improved outcomes. We sought to evaluate outcomes of patients with hepatocellular carcinoma (HCC) with and without viral hepatitis (hepatitis B and C) treated with lobar yttrium-90 radioembolization (Y-90 RE). METHODS: After IRB approval, an institutional database of patients with HCC who received RE between 2009-2014 was queried and 99 patients were identified that received a total of 122 lobar RE. Charts were reviewed to capture previous treatments, viral hepatitis status, α-fetoprotein values (AFP), Child-Pugh class (CP), albumin-bilirubin score (ALBI), portal vein thrombosis (PVT), volumes treated and doses delivered. Comparison was made with Chi-square and Mann-Whitney U test. Intrahepatic control (IHC), extrahepatic control (EHC), progression free survival (PFS), and overall survival (OS) were calculated according to the Kaplan-Meier method stratified by cause of underlying liver disease (viral vs. non-viral) and survival differences were assessed via the log-rank test. Hazard ratios were calculated using Cox regression. RESULTS: Median follow up for VA HCC and non-VA (NVA) HCC patients was 10.9 months (range, 0.8-46.7 months) and 11.8 months (range, 1.1-62.8 months), respectively. Patients with VA HCC (n=44) were younger (P<0.001) and had smaller pretreatment liver volumes (P<0.001); however, there was no difference with respect to gender, pre-treatment AFP, CP, ALBI, PVT, extrahepatic disease, previous treatment, or dose delivered. Median doses for VA and NVA HCC patients were 129.5 Gy (range, 90-215.8 Gy) and 131 Gy (range, 100.9-265 Gy), respectively (P=0.75). One year IHC showed a strong trend to better control for VA HCC at 67% versus 34% for NVA HCC (P=0.067) but 1 year EHC was significantly worse at 63% for VA HCC versus 86% for NVA HCC (P=0.027). There were no significant differences in survival, with a 1-year PFS of 45% for VA HCC versus 31% for NVA HCC (P=0.56) and 1 year OS of 46% versus 55% (P=0.55). Patients that received salvage treatments, CP A, no PVT, and those without extrahepatic disease had improved OS. CONCLUSIONS: Patients with VA HCC had a trend to improved IHC and significantly worse EHC. Prospective investigation of novel systemic therapies following Y-90 RE in patients with VA HCC is warranted to potentially further extend survival in VA HCC patients by addressing extra-hepatic disease.

Patient choice for high-volume center radiation impacts head and neck cancer outcome.

BACKGROUND: Studies suggest treatment outcomes may vary between high (HVC)- and low-volume centers (LVC). Radiation therapy (RT) for head and neck cancer (HNC) requires weeks of treatment, the inconvenience of which may influence a patient's choice for treatment location. We hypothesized that receipt of RT for HNC at a HVC would influence outcomes compared to patients evaluated at a HVC, but who chose to receive RT at a LVC. METHODS: From 1998 to 2011, 1930 HNC patients were evaluated at a HVC and then treated with RT at either a HVC or LVC. Time-to-event outcomes and treatment factors were compared. RESULTS: Median follow-up was 34 months. RT was delivered at a HVC for 1368 (71%) patients and at a LVC in 562 (29%). Patients were more likely to choose HVC-RT if they resided in the HVC's county or required definitive RT (all P < 0.001). HVC-RT was associated with a significant improvement in 3-year LRC (84% vs 68%), DFS (68% vs 48%), and OS (72% vs 57%) (all P < 0.001). On multivariate analysis (MVA), HVC-RT independently predicted for improved LRC, DFS, and OS (all P < 0.05). CONCLUSIONS: In patients evaluated at a HVC, the choice of RT location was primarily influenced by their residing distance from the HVC. HVC-RT was associated with improvements in LRC, DFS, and OS in HNC. As treatment planning and delivery are technically demanding in HNC, the choice to undergo treatment at a HVC may result in more optimal delivered dose, RT duration, and outcome.

Low-dose-rate Brachytherapy for Prostate Cancer in Low-resource Settings.

PURPOSE: In areas with limited health care, it is important to identify and implement effective treatment methods and to optimize available resources. We investigated the implementation of a low-dose-rate (LDR) brachytherapy program for the treatment of prostate cancer (PCa) in a low-resource setting such as Puerto Rico (PR), where PCa is the main cause of cancer-associated death. METHODS AND MATERIALS: After institutional approval, the medical records of patients with nonmetastatic PCa undergoing LDR brachytherapy from 2008 to 2013 were reviewed from PR. The factors analyzed included adequate D90 (radiation dose delivered to 90% of the target volume) coverage (≥140 Gy), early and late toxicity (Common Terminology Criteria for Adverse Events grade >2), and prostate-specific antigen failure. Freedom from biochemical failure was evaluated using Kaplan-Meier analysis. RESULTS: The barriers to implementation of LDR brachytherapy in a country with limited resources were identified. These included lack of access to funding for startup costs, specific referral patterns, lack of trained support staff, such as dosimetrists and physicists, and initial opposition from insurance companies for reimbursement. The initial results from 191 patients were included in the present study with a median follow-up period of 26 months. Prostate-specific antigen failure occurred in 6 patients (3%). No early or late gastrointestinal toxicity (grade >2) developed. Only 3 (2%) and 2 (1%) patients experienced early and late genitourinary toxicity (grade >2), respectively. The 2- and 3-year freedom from biochemical failure in this population was 97% and 95.9%, respectively. CONCLUSIONS: At present, limited data are available delineating the barriers faced by low-resource settings in the implementation of LDR brachytherapy. Our data highlight the issues unique to this environment and support the use of LDR brachytherapy as a reliable and effective treatment modality for patients with PCa in low-resource settings.

Priming radioimmunotherapy with external beam radiation in patients with relapsed low grade non-Hodgkin lymphoma.

BACKGROUND: The aim of this study was to evaluate the outcomes of priming salvage radioimmunotherapy (RIT) with a low dose of external beam radiotherapy (EBRT) in patients with relapsed low grade non-Hodgkin lymphoma (LG-NHL). METHODS: Patients who received salvage RIT with or without 2 × 2 Gy EBRT between March 2009 and February 2013 were retrospectively reviewed at a single institution. Planning target volume (PTV) for EBRT was created by adding a 1-2 cm expansion to the gross tumor volume depending on the anatomical location. Kaplan-Meier method via log-rank was employed to analyze the endpoints freedom from progression (FFP) and overall survival (OS). RESULTS: We identified 22 patients who received salvage RIT without chemotherapy with a median follow up of 34 months. Of these, 9 (41%) patients were treated with EBRT immediately prior to RIT, and 13 (59%) received salvage RIT alone. Median FFP was not reached in patients who underwent combination treatment, while it was 9 months for patients treated with RIT alone (p = 0.02). OS for all patients at 36 months was 80.3% with no significant difference between the two groups (p = 0.88). On univariate analysis, the addition of EBRT was associated with improved FFP [hazard ratio (HR) = 4.17; 95% confidence interval (CI), 1.24-19.1; p = 0.02)]. No long term toxicities were reported in both groups. CONCLUSIONS: RIT outcomes and effects were improved with addition of low-dose EBRT immediately prior to it, in the treatment of relapsed LG-NHL with no additional toxicity. This study is hypothesis-generating and the findings should be validated in prospective studies.

Staged reconstruction brachytherapy has lower overall cost in recurrent soft-tissue sarcoma.

PURPOSE: Adjuvant brachytherapy (AB) with immediate (IR) and staged reconstruction (SR) are distinct treatment modalities available for patients with recurrent soft tissue sarcoma (STS). Although SR may offer local control and toxicity benefit, it requires additional upfront procedures, and there is no evidence that it improves overall survival. With the importance of value-based care, our goal is to identify which technique is more cost effective. MATERIAL AND METHODS: A retrospective review of 22 patients with recurrent extremity STS treated with resection followed by AB alone. Hospital charges were used to compare the cost between SR and IR at the time of initial treatment, at 6-month intervals following surgery, and cumulative cost comparisons at 18 months. RESULTS: Median follow-up was 31 months. Staged reconstruction (n = 12) was associated with an 18-month local control benefit (85% vs. 42%, p = 0.034), compared to IR (n = 10). Staged reconstruction had a longer hospital stay during initial treatment (10 vs. 3 days, p = 0.002), but at 18 months, the total hospital stay was no longer different (11 vs. 11 days). Initially, there was no difference in the cost of SR and IR. With longer follow-up, cost eventually favored SR, which was attributed primarily to the costs associated with local failure (LF). On multivariate analysis, cost of initial treatment was associated with length of hospital stay (~$4.5K per hospital day, p < 0.001), and at 18 months, the cumulative cost was ~175K lower with SR (p = 0.005) and $58K higher with LF (p = 0.02). CONCLUSIONS: In recurrent STS, SR has a longer initial hospital stay when compared to IR. At 18 months, SR had lower rates of LF, translating to lower total costs for the patient. SR is the more cost-effective brachytherapy approach in the treatment of STS, and should be considered as healthcare transitions into value-based medicine.

Systematic review of case reports on the abscopal effect.

Radiation therapy is a highly effective local treatment for cancer. However, sporadic events of tumor regression in unirradiated fields, known as abscopal effect, have been observed for decades. This abscopal effect has more recently been postulated to be a result of antitumor immune response induced by radiation therapy. With the advent of modern immunotherapy, the potential for immune activation by radiation therapy defines a novel role for radiation therapy in systemic disease. In this context, we have searched documented cases abscopal effect of radiation therapy in literature. A total of 46 reported cases have been identified from 1969 to 2014 with median radiation dose of 31 Gy, median follow-up of 17.5 months, and median documented time to notice the abscopal effect was 2 months. This review systematically summarizes all clinical case reports of abscopal effect to gain insight into this uncommon but important phenomenon.

The impact of body mass index on dosimetric quality in low-dose-rate prostate brachytherapy.

PURPOSE: Low-dose-rate (LDR) brachytherapy has been established as an effective and safe treatment option for men with low and intermediate risk prostate cancer. In this retrospective analysis, we sought to study the effect of body mass index (BMI) on post-implant dosimetric quality. MATERIAL AND METHODS: After institutional approval, records of patients with non-metastatic prostate cancer treated in Puerto Rico with LDR brachytherapy during 2008-2013 were reviewed. All patients were implanted with 125I seeds to a prescription dose of 145 Gy. Computed tomography (CT) based dosimetry was performed 1 month after implant. Patients with at least 1 year of prostate-specific antigen (PSA) follow-up were included. Factors predictive of adequate D90 coverage (≥ 140 Gy) were compared via the Pearson χ2 or Wilcoxon rank-sum test as appropriate. RESULTS: One-hundred and four patients were included in this study, with 53 (51%) patients having a D90 ≥ 140 Gy. The only factor associated with a dosimetric coverage detriment (D90 < 140 Gy) was BMI ≥ 25 kg/m2 (p = 0.03). Prostate volume (p = 0.26), initial PSA (p = 0.236), age (p = 0.49), hormone use (p = 0.93), percent of cores positive (p = 0.95), risk group (p = 0.24), tumor stage (p = 0.66), and Gleason score (p = 0.61) did not predict D90. CONCLUSIONS: In this study we show that BMI is a significant pre-implant predictor of D90 (< 140 Gy vs. ≥ 140 Gy). Although other studies have reported that prostate volume also affects D90, our study did not find this correlation to be statistically significant, likely because all of our patients had a prostate volume < 50 cc. Our study suggests that in patients with higher BMI values, more rigorous peri-implant dosimetric parameters may need to be applied in order to achieve a target D90 > 140 Gy.

Postoperative Stereotactic Radiosurgery Using 5-Gy × 5 Sessions in the Management of Brain Metastases.

BACKGROUND: Multiple regimens for stereotactic radiosurgery (SRS) at the postoperative bed have shown a high local control rate and a low toxicity profile with no decrease in overall survival with the omission of whole-brain radiation therapy. METHODS: In this retrospective analysis, we evaluate our experience with postoperative SRS using a uniform regimen of 25 Gy in 5 sessions. RESULTS: Between April 2011 and May 2014, 75 patients were treated for 77 metastatic brain lesions with postoperative SRS in 5 sessions. The median planning target volume was 13.8 cm(3) (1.93-128.43 cm(3)) with a median follow-up for all lesions of 9.5 months (range, 1.2-38.2 months). Kaplan-Meier estimates of local control at 1 and 2 years were 88.8% and 83.9%, respectively. On univariate analysis, a trend in decreased survival with multiple brain lesions was noted (hazard ratio [HR] = 2; 95% confidence interval [CI], 0.87-4.53; P = 0.10). There was a trend towards decreased local control with radioresistant tumors (HR = 3.23; 95% CI, 0.7-22.6; P = 0.14) and planning target volume ≥17 cm(3) (HR = 3.07; 95% CI, 0.73-15.23; P = 0.12). Two (3%) patients developed radionecrosis, one of whom required craniotomy. CONCLUSIONS: SRS with a dose of 25 Gy in 5 sessions is associated with excellent local control at the resection site with minimal toxicity in the postoperative settings in our patient population. Further investigation is required to determine if dose escalation to the postoperative cavity of radioresistant tumors improves outcomes.

Treatment delays, race, and outcomes in head and neck cancer.

PURPOSE: Patient race has been shown to predict for differences in outcomes and has been attributed to socioeconomic factors such as social support and access to healthcare. In head and neck cancer (HNC), a disease without recommended screening, we sought to investigate the association between race, treatment delays and outcome. METHODS: Records of 1802 patients with non-metastatic squamous cell HNC treated between 1998 and 2013 were retrospectively assessed from an institutional database. Patient demographics, tumor and treatment characteristics, and patient outcomes were abstracted from the chart. Differences between groups were assessed via logistic regression multivariate analysis (MVA). Outcomes including locoregional control (LRC) and overall survival (OS) were then estimated via Kaplan-Meier and Cox-regression MVA. RESULTS: Median follow up was 34 months. Patient races included white (n=1671, 93%), black (n=80, 4%), Asian (n=18, 1%), and other (n=33, 2%). On logistic regression MVA, Black patients were less likely to be married (39% vs. 63%; OR 0.5 95%CI 0.30-0.83, p=0.007) or be currently employed (43% vs. 61%; OR 0.44 95%CI 0.26-0.74, p=0.002) when compared to non-blacks. Black patients were also younger (54 vs. 59 years, p=0.001), more likely to present with advanced tumor stage (T4: 48% vs. 25%), and more often had >45days elapsed from diagnosis to treatment initiation (DTI) (61% vs. 49%, p=0.028). Delays in treatment, such as delayed diagnosis (advanced disease presentation) and delays in DTI>45days were also associated with marital and employment status. Black patients were associated with a lower 3-year LRC rate (65% vs. 81%, p<0.001) and OS rate (43% vs. 69%, p<0.001), compared to non-black patients. Patients with >45days DTI had a detriment in 3-year LRC (77% vs. 83%, p=0.002) and OS (66% vs. 69%, p=0.009). On Cox MVA, black race was independently prognostic for worse LRC (HR 1.62 95%CI 1.04-2.51, p=0.033) and OS (HR 1.55 95%CI 1.15-2.08, p=0.004) vs. non-blacks. CONCLUSION: Black race is independently prognostic for LRC and OS. Delays in HNC treatment, such as more advanced tumor stage presentation and delays in treatment initiation, may be attributed to socioeconomic factors such as employment status and social support. Efforts to accommodate these factors may expedite treatment, in hopes of improving the race related outcome disparity in HNC.

Radiosensitivity Differences Between Liver Metastases Based on Primary Histology Suggest Implications for Clinical Outcomes After Stereotactic Body Radiation Therapy.

PURPOSE/OBJECTIVES: Evidence from the management of oligometastases with stereotactic body radiation therapy (SBRT) reveals differences in outcomes based on primary histology. We have previously identified a multigene expression index for tumor radiosensitivity (RSI) with validation in multiple independent cohorts. In this study, we assessed RSI in liver metastases and assessed our clinical outcomes after SBRT based on primary histology. METHODS AND MATERIALS: Patients were identified from our prospective, observational protocol. The previously tested RSI 10 gene assay was run on samples and calculated using the published algorithm. An independent cohort of 33 patients with 38 liver metastases treated with SBRT was used for clinical correlation. RESULTS: A total of 372 unique metastatic liver lesions were identified for inclusion from our prospective, institutional metadata pool. The most common primary histologies for liver metastases were colorectal adenocarcinoma (n=314, 84.4%), breast adenocarcinoma (n=12, 3.2%), and pancreas neuroendocrine (n=11, 3%). There were significant differences in RSI of liver metastases based on histology. The median RSIs for liver metastases in descending order of radioresistance were gastrointestinal stromal tumor (0.57), melanoma (0.53), colorectal neuroendocrine (0.46), pancreas neuroendocrine (0.44), colorectal adenocarcinoma (0.43), breast adenocarcinoma (0.35), lung adenocarcinoma (0.31), pancreas adenocarcinoma (0.27), anal squamous cell cancer (0.22), and small intestine neuroendocrine (0.21) (P<.0001). The 12-month and 24-month Kaplan-Meier rates of local control (LC) for colorectal lesions from the independent clinical cohort were 79% and 59%, compared with 100% for noncolorectal lesions (P=.019), respectively. CONCLUSIONS: In this analysis, we found significant differences based on primary histology. This study suggests that primary histology may be an important factor to consider in SBRT radiation dose selection.