Stable Isotope-Assisted Untargeted Metabolomics Identifies ALDH1A1-Driven Erythronate Accumulation in Lung Cancer Cells

Using an untargeted stable isotope-assisted metabolomics approach, we identify erythronate as a metabolite that accumulates in several human cancer cell lines. Erythronate has been reported to be a detoxification product derived from off-target glycolytic metabolism. We use chemical inhibitors and genetic silencing to define the pentose phosphate pathway intermediate erythrose 4-phosphate (E4P) as the starting substrate for erythronate production. However, following enzyme assay-coupled protein fractionation and subsequent proteomics analysis, we identify aldehyde dehydrogenase 1A1 (ALDH1A1) as the predominant contributor to erythrose oxidation to erythronate in cell extracts. Through modulating ALDH1A1 expression in cancer cell lines, we provide additional support. We hence describe a possible alternative route to erythronate production involving the dephosphorylation of E4P to form erythrose, followed by its oxidation by ALDH1A1. Finally, we measure increased erythronate concentrations in tumors relative to adjacent normal tissues from lung cancer patients. These findings suggest the accumulation of erythronate to be an example of metabolic reprogramming in cancer cells, raising the possibility that elevated levels of erythronate may serve as a biomarker of certain types of cancer.

Evaluation of Pneumonitis in a Phase II Study of Consolidation Immunotherapy with Nivolumab and Ipilimumab or Nivolumab Alone following Concurrent Chemoradiotherapy for Unresectable Stage IIIA/IIIB Non-small Cell Lung Cancer (NSCLC)

PURPOSE/OBJECTIVE(S)

Unresectable stage III Non-Small-Cell-Lung-Cancer (NSCLC) has had an evolving landscape of treatment options with the approvals of immuno-oncologic (IO) therapy. There have been relatively few studies that have evaluated the risk of pneumonitis in patients receiving IO after concurrent chemoradiation treatment (CCRT). This study is to evaluate the relationship of pneumonitis and radiation dose in patients receiving consolidative IO with Nivolumab or Nivolumab plus ipilimumab.

MATERIALS/METHODS

Patients with stage III NSCLC who underwent CCRT were enrolled on BTCRC-LUN16-081, a randomized phase II trial assessing the efficacy of nivolumab or nivolumab plus ipilimumab as consolidation therapy. These patients were evaluated for radiation dose parameters and correlation with pneumonitis was examined.

RESULTS

After CCRT, patients were enrolled to receive consolidative IO therapy on BTCRC-LUN16-081, and 104 patients had Dose Volume Histogram (DVH) information available for analysis. Of these patients, 58 (55.8%) had stage IIIA and 46 (44.2%) had stage IIIB disease according to 7th edition IASLC. During this period 29 patients (27.9%) had at least grade 2 pneumonitis. Utilizing logistic regression and evaluating different cut offs for lung V20, patients receiving a V20 of greater than 23% had a higher risk of grade 2 or greater pneumonitis (p-value 0.0246, 38% vs. 16%). There was no significant difference in rates of pneumonitis between the two different IO regimens. Traditional lung DVH cutoffs (V5>65%, V20>35%, mean >20 Gy) were not associated with pneumonitis in this study.

CONCLUSION

The use of nivolumab or nivolumab plus ipilimumab after definitive CCRT is safe and effective. Lung V20 > 23% was associated with a higher risk of Grade 2 or higher pneumonitis. Radiation dose constraints for lungs in patients receiving consolidative IO after CCRT should continue to be evaluated and optimized when feasible.

Radiosurgery Dose Reduction for Brain Metastases on Immunotherapy (RADREMI): One-Year Safety and Efficacy Outcomes from a Multicenter Phase I Trial

PURPOSE/OBJECTIVE(S)

The combination of immunotherapy and single-fraction stereotactic radiosurgery (SRS) for treatment of metastatic brain disease has yielded symptomatic radiation necrosis rates as high as 20% (PMID: 29327059). Consequently, the Radiosurgery Dose Reduction for Brain Metastases on Immunotherapy (RADREMI) multicenter phase I trial (registered at clinicaltrials.gov, NCT04047602) was created to address whether reduced-dose SRS can improve morbidity without compromising efficacy. In this report we present our one-year findings.

MATERIALS/METHODS

Eligibility for RADREMI enrollment required brain metastases patients with: a) Histologically-confirmed primary malignancy, b) Receipt of immunotherapy within 30 days of SRS, c) 1-10 MRI-visible brain metastases, d) Estimated median survival of at least 6 months (via disease-specific graded prognostic assessment), and e) No history of whole brain radiation therapy. Reduced-dose SRS utilized 18 Gy for lesions 0-2 cm, 14 Gy for lesions 2.1-3 cm, and 12 Gy for lesions 3.1-4 cm. Symptomatic radiation necrosis was defined as imaging findings consistent with radiation necrosis combined with clinical symptoms requiring steroid administration and/or operative intervention. Local control was defined by Response Assessment in Neuro-Oncology (RANO) criteria.

RESULTS

From December 18, 2019 to June 30, 2022, 54 lesions in 17 patients were treated on RADREMI with at least one-year of follow-up. One-year local control occurred in 52 of 54 lesions and in 15 of 17 patients, yielding control rates of 96% per lesion and 88% per patient. Radiographic radiation necrosis occurred in 2 of 54 lesions (4%). No symptomatic radiation necrosis occurred.

CONCLUSION

Our findings of concurrent immunotherapy + reduced-dose SRS at one-year post-treatment revealed excellent local control (96%) with no symptomatic radiation necrosis, and minimal radiographic radiation necrosis. These results attest to the durability of the safety and efficacy of reduced-dose SRS with immunotherapy for metastatic brain disease.

Supplementary Figures S1 to S14 from Methionine and Kynurenine Activate Oncogenic Kinases in Glioblastoma, and Methionine Deprivation Compromises Proliferation.. [DOI: 10.1158/1078-0432.22454478.v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

<p>Supporting Figures Figure S1. Extracellular and intracellular metabolites of commercially available and patient derived GBM cells and NHAs Figure S2. Total and extracted ion chromatograms of intracellular metabolites Figure S3. Total and extracted ion chromatograms of extracellular metabolites Figure S4. Targeted analysis MS/MS product ion spectrum of methionine Figure S5. Targeted analysis MS/MS product ion spectrum of tryptophan Figure S6. Targeted analysis MS/MS product ion spectrum of kynurenine Figure S7. Targeted analysis MS/MS product ion spectrum of MTA Figure S8. Total ion chromatogram and multiple reaction monitoring of different concentrations of methionine Figure S9. Total ion chromatogram and multiple reaction monitoring of different concentrations of kynurenine Figure S10. Key metabolites in methionine pathway Figure S11. Calibration Curve and Multiple Reaction Monitoring of SAM and SAH Figure S12. Key metabolites in tryptophan pathway Figure S13. Insilico analysis - Connecting metabolome and proteome in GBM cells Figure S14. Densitometric quantification of the chemiluminescence signals</p>

Radiosurgery dose reduction for brain metastases on immunotherapy (RADREMI): Results of an a priori interim analysis of a multicenter phase I trial

2013

Background: Symptomatic radiation necrosis rates in patients treated with immune checkpoint inhibitor (ICI) therapy and concomitant single-fraction stereotactic radiosurgery (SRS) are as high as 20% (PMID: 29327059). We present updated results from the Radiosurgery Dose Reduction for Brain Metastases on Immunotherapy (RADREMI) trial following completion of an a priori interim analysis, aimed to identify reduced-dose SRS that is safe and efficacious for this patient population. Methods: RADREMI (clinicaltrials.gov, NCT04047602) is a prospective multicenter single arm Phase I trial involving patients age > 18 receiving ICI with SRS for 1-10 brain metastases on MRI. Patients had biopsy-confirmed primary malignancy with disease-specific graded prognostic assessment estimated median survival of at least 6 months and no previous whole brain radiation therapy. Six-month symptomatic radiation necrosis (radiographic radiation necrosis + clinical symptoms requiring steroid administration and/or operative intervention) was the primary endpoint, based on an expected rate of 5% and a historical rate of 16%. Secondary endpoints included 6-month local control and radiographic radiation necrosis. Response Assessment in Neuro-Oncology criteria defined local control; findings were compared to historical 6-month local control of 87-91% with RTOG 90-05 SRS dosing. A pre-determined interim futility analysis (based on the null hypothesis of no fewer than 15 of the first 20 patients reaching the primary endpoint achieving 6-month local control for RADREMI dosing) was performed using the Fisher’s exact test. Results: Between December 18, 2019 and September 10, 2021, 43 lesions were treated in 16 patients receiving ICI delivered within 30 days before SRS who were enrolled on trial and met the primary endpoint (median follow-up = 9.1 months). All patients received RADREMI SRS dosing (18 Gy for lesions 0-2 cm, 14 Gy for lesions 2.1-3 cm, and 12 Gy for lesions 3.1-4 cm). The most common ICI used was single-agent pembrolizumab (51% of lesions, 56% of patients), followed by single-agent nivolumab (28% of lesions, 13% of patients). The six-month rates of symptomatic and radiographic radiation necrosis were zero; the six-month local control rate was 98% per treated lesion (42/43), and 94% per treated patient (15/16), comparable to historical controls (p > 0.05) and sufficient to not reject the interim futility analysis null hypothesis. Conclusions: Interim analysis reveals that the safety and efficacy of RADREMI dosing for reducing SRS dose in brain metastasis patients receiving concomitant ICI persists with excellent local control and no morbidity in a multi-institutional collaborative trial. Further results following completion of trial enrollment will provide additional evidence regarding the safety and efficacy of RADREMI SRS dosing. Clinical trial information: NCT04047602.

Local and distant brain control in melanoma and NSCLC brain metastases with concurrent radiosurgery and immune checkpoint inhibition

INTRODUCTION

The treatment of brain metastases with stereotactic radiosurgery (SRS) in combination with immune checkpoint inhibitors (ICI) has become more common in recent years, but there is a lack of prospective data on cancer control outcomes when these therapies are administered concurrently.

METHODS

Data were retrospectively reviewed for patients with non-small cell lung cancer (NSCLC) and melanoma brain metastases treated with SRS at a single institution from May 2008 to January 2017. A parametric proportional hazard model is used to detect the effect of concurrent ICI within 30, 60, or 90 days of ICI administration on local control and distant in-brain control. Other patient and lesion characteristics are treated as covariates and adjusted in the regression. A frailty term is added in the baseline hazard to capture the within-patient correlation.

RESULTS

We identified 144 patients with 477 total lesions, including 95 NSCLC patients (66.0%), and 49 (34.0%) melanoma patients. On multivariate analysis, concurrent SRS and ICI (SRS within 30 days of ICI administration) was not associated with local control but was associated with distant brain control. When controlling for prior treatment to lesion, number of lesions, and presence of extracranial metastases, patients receiving this combination had a statistically significant decrease in distant brain failure compared to patients that received non-concurrent ICI or no ICI (HR 0.15; 95% CI 0.05-0.47, p = 0.0011).

CONCLUSION

Concurrent ICI can enhance the efficacy of SRS. Prospective studies would allow for stronger evidence to support the impact of concurrent SRS and ICI on disease outcomes.

Lymphocyte depletion rate as a biomarker of radiation dose to circulating lymphocytes during fractionated partial-body radiotherapy

Purpose

Radiation causes exponential depletion of circulating lymphocyte populations; in turn, radiation-induced lymphopenia is associated with worse survival for many solid tumors, possibly owing to attenuated antitumor immune responses. Identifying reliable and reproducible methods of calculating the radiation dose to circulating immune cells may facilitate development of techniques to reduce the risk and severity of radiation-induced toxic effects to circulating lymphocytes.

Methods and Materials

Patient-specific lymphocyte loss rates were derived from a clinical data set including 684 adult patients with solid tumors. Multivariable linear regression was used to model the relationship between the lymphocyte loss rate and physical parameters of the radiation plan that determine circulating blood dose.

Results

During partial-body radiation, lymphocyte loss rates are determined by physical parameters of the radiation plan that reflect radiation exposure to circulating cells, including target volume size, dose per fraction squared, and anatomic site treated. Differences in observed versus predicted lymphocyte loss rates may be partly explained by variations in concurrent chemotherapy regimens.

Conclusions

We describe a novel method of using patient-specific lymphocyte loss kinetics to approximate the effective radiation dose to circulating lymphocytes during focal fractionated photon radiation therapy. Clinical applications of these findings include the early identification of patients at particularly high risk of severe radiation-induced lymphopenia based on physical parameters of the radiation therapy plan.

Discovery of increased number or interval growth of brain metastases on same-day GammaKnife™ planning MRI: Predicting factors and patient outcomes

Purpose

To determine factors associated with increased risk of finding new and/or enlarged brain metastases (BM) on GammaKnife™ (GK) MRI and their impact on patient outcomes.

Results

43.9% of patients showed BM growth, 32.9% had additional brain metastases (aBM), and 18.1 % had both. Initial brain metastasis velocity (iBMV) was associated with finding aBM. Time between diagnostic MRI (dMRI) and GK MRI was associated with interval growth and each day increased this risk by 2%. Prior brain metastasectomy and greater time between either dMRI or latest extracranial RT and GK MRI predicted both aBM and BM growth. aBM and/or BM growth led to management change in 1.8% of cases and were not associated with OS or incidence of distant intracranial failure.

Conclusions

Number of metastases seen on dMRI and iBMV predicted both aBM and/or BM growth, however, these factors did not significantly affect survival or incidence of distant intracranial failure.

Genetic Variations in the Transforming Growth Factor-β1 Pathway May Improve Predictive Power for Overall Survival in Non-small Cell Lung Cancer

Purpose: Transforming growth factor-β1 (TGF-β1), a known immune suppressor, plays an important role in tumor progression and overall survival (OS) in many types of cancers. We hypothesized that genetic variations of single nucleotide polymorphisms (SNPs) in the TGF-β1 pathway can predict survival in patients with non-small cell lung cancer (NSCLC) after radiation therapy. Materials and Methods: Fourteen functional SNPs in the TGF-β1 pathway were measured in 166 patients with NSCLC enrolled in a multi-center clinical trial. Clinical factors, including age, gender, ethnicity, smoking status, stage group, histology, Karnofsky Performance Status, equivalent dose at 2 Gy fractions (EQD2), and the use of chemotherapy, were first tested under the univariate Cox's proportional hazards model. All significant clinical predictors were combined as a group of predictors named "Clinical." The significant SNPs under the Cox proportional hazards model were combined as a group of predictors named "SNP." The predictive powers of models using Clinical and Clinical + SNP were compared with the cross-validation concordance index (C-index) of random forest models. Results: Age, gender, stage group, smoking, histology, and EQD2 were identified as significant clinical predictors: Clinical. Among 14 SNPs, BMP2:rs235756 (HR = 0.63; 95% CI:0.42-0.93; p = 0.022), SMAD9:rs7333607 (HR = 2.79; 95% CI 1.22-6.41; p = 0.015), SMAD3:rs12102171 (HR = 0.68; 95% CI: 0.46-1.00; p = 0.050), and SMAD4: rs12456284 (HR = 0.63; 95% CI: 0.43-0.92; p = 0.016) were identified as powerful predictors of SNP. After adding SNP, the C-index of the model increased from 84.1 to 87.6% at 24 months and from 79.4 to 84.4% at 36 months. Conclusion: Genetic variations in the TGF-β1 pathway have the potential to improve the prediction accuracy for OS in patients with NSCLC.

Radiosurgery dose reduction for brain metastases on immunotherapy (RADREMI): Early results from a multicenter phase I trial

2025

Background: The rate of symptomatic radiation necrosis in patients treated with immune checkpoint inhibitor (ICI) therapy and concomitant single-fraction stereotactic radiosurgery (SRS) is as high as 20% (Martin et al., JAMA Oncology 2018). Here, we present the first results from the Radiosurgery Dose Reduction for Brain Metastases on Immunotherapy (RADREMI) trial, aimed to identify reduced-dose SRS that is safe and efficacious for this patient population. Methods: RADREMI is a prospective multicenter, single arm phase I pilot study. Patients age > 18 receiving ICI with SRS for 1-10 brain metastases on MRI from biopsy-confirmed primary malignancy with estimated median survival of at least 6 months (by disease-specific graded prognostic assessment) and no history of whole brain radiation therapy were eligible. The primary endpoint was six-month symptomatic radiation necrosis (defined as a six-month rate of clinical symptomatology requiring steroid administration and/or operative intervention concomitant with imaging findings consistent with radiation necrosis), based on a historical six-month symptomatic radiation necrosis rate of 16% and an expected rate of 5%. Secondary endpoints included six-month local control and six-month radiographic radiation necrosis. Local control was defined according to Response Assessment in Neuro-Oncology (RANO) criteria, and was compared to historical controls of 87-91% six-month local control with RTOG 90-05 SRS dosing. The Fisher’s exact test was used for statistical analysis. This trial is registered at clinicaltrials.gov, NCT04047602. Results: Between December 18, 2019 and January 21, 2021, 39 lesions were treated in 17 patients receiving ICI delivered within 30 days before SRS from whom we recruited and obtained consent. All patients were treated with RADREMI dosing, which involved SRS doses of 18 Gy for lesions 0-2 cm, 14 Gy for lesions 2.1-3 cm, and 12 Gy for lesions 3.1-4 cm. The most common ICI used was single-agent pembrolizumab (49% of lesions, 59% of patients), followed by single-agent nivolumab (31% of lesions, 12% of patients). For the 11 lesions (six patients) meeting the primary endpoint (median follow-up = 259 days), the six-month symptomatic radiation necrosis rate was 0% per treated lesion, and 0% per treated patient, which was not significantly different from historical controls (p = 0.478). The six-month local control rate was 100% per treated lesion, and 100% per treated patient, comparable to historical controls (p = 0.476). Conclusions: In the first prospective trial to investigate dose-reduced SRS with concomitant ICI in treating metastatic brain disease, early results support the safety and efficacy of RADREMI dosing in this patient population. These findings warrant further multi-institutional collaborative trials of RADREMI dosing for this population. Clinical trial information: NCT04047602.

Feasibility of Performing Transvascular Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration

BACKGROUND

Thoracic vascular structures often preclude transbronchial access to central lung parenchymal lesions and lymph nodes, thereby necessitating either a surgical or transvascular needle aspiration (TVNA) approach for diagnostic sampling. The aim of this study was to evaluate the safety and efficacy of endobronchial ultrasound (EBUS) TVNA in the diagnosis and staging of mediastinal tumors.

PATIENTS AND METHODS

We performed a retrospective analysis of 35 cases of EBUS-TVNA. Cases were reviewed in the Cerner electronic medical records between March 2013 and October 2018. Records were reviewed for patient comorbidities, smoking status, anticoagulation intake, procedural details, sample results, and postprocedural complications.

RESULTS

Thirty-five EBUS-TVNA procedures were reviewed. Twenty-nine of them were performed by traversing the main pulmonary artery or its branches. Three involved transvascular access through the azygous vein, 2 via the brachiocephalic artery and 1 through the superior vena cava. Only 4 patients (11.4%) experienced postprocedural complications, which included mild hemoptysis, moderate hemoptysis requiring epinephrine and saline infusion, acute exacerbation of chronic obstructive pulmonary disease, and a rapid ventricular rate on top of preexisting atrial fibrillation. The yield of TVNA for malignancy was 22 (95.6%) of 23 patients. Overall yield was 31 (88.6%) of 35, with a need for additional intervention in 4 (11.4%) of 35 patients. Mutational analysis was adequate when ordered.

CONCLUSION

In our single-center experience, the EBUS-TVNA procedure had a high diagnostic yield and was associated with low rates of postprocedural complications. Further trials are needed to assess its efficacy compared to more invasive procedures.

Demographic factors associated with missed follow-up among solid tumor patients treated at a large multi-site academic institution

Aim: To identify demographic predictors of patients who miss oncology follow-up, considering that missed follow-up has not been well studies in cancer patients. Methods: Patients with solid tumors diagnosed from 2007 to 2016 were analyzed (n = 16,080). Univariate and multivariable logistic regression models were constructed to examine predictors of missed follow-up. Results: Our study revealed that 21.2% of patients missed ≥1 follow-up appointment. African-American race (odds ratio [OR] 1.33; 95% CI: 1.17-1.51), Medicaid insurance (OR 1.59; 1.36-1.87), no insurance (OR 1.66; 1.32-2.10) and rural residence (OR 1.78; 1.49-2.13) were associated with missed follow-up. Conclusion: Many cancer patients miss follow-up, and inadequate follow-up may influence cancer outcomes. Further research is needed on how to address disparities in follow-up care in high-risk patients.

Baseline Karnofsky performance status is independently predictive of death within 30 days of intracranial radiation therapy completion for metastatic disease

Introduction

For patients with brain metastases, palliative radiation therapy (RT) has long been a standard of care for improving quality of life and optimizing intracranial disease control. The duration of time between completion of palliative RT and patient death has rarely been evaluated.

Methods

A compilation of two prospective institutional databases encompassing April 2015 through December 2018 was used to identify patients who received palliative intracranial radiation therapy. A multivariate logistic regression model characterized patients adjusting for age, sex, admission status (inpatient versus outpatient), Karnofsky Performance Status (KPS), and radiation therapy indication.

Results

136 consecutive patients received intracranial palliative radiation therapy. Patients with baseline KPS <70 (OR = 2.2; 95%CI = 1.6-3.1; p < 0.0001) were significantly more likely to die within 30 days of treatment. Intracranial palliative radiation therapy was most commonly delivered to provide local control (66% of patients) or alleviate neurologic symptoms (32% of patients), and was most commonly delivered via whole brain radiation therapy in 10 fractions to 30 Gy (38% of patients). Of the 42 patients who died within 30 days of RT, 31 (74%) received at least 10 fractions.

Conclusions

Our findings indicate that baseline KPS <70 is independently predictive of death within 30 days of palliative intracranial RT, and that a large majority of patients who died within 30 days received at least 10 fractions. These results indicate that for poor performance status patients requiring palliative intracranial radiation, hypofractionated RT courses should be strongly considered.

Radiosurgery dose reduction for brain metastases on immunotherapy (RADREMI): A prospective phase I study protocol

INTRODUCTION

Up to 20% of patients with brain metastases treated with immune checkpoint inhibitor (ICI) therapy and concomitant stereotactic radiosurgery (SRS) suffer from symptomatic radiation necrosis. The goal of this study is to evaluate Radiosurgery Dose Reduction for Brain Metastases on Immunotherapy (RADREMI) on six-month symptomatic radiation necrosis rates.

METHODS

This study is a prospective single arm Phase I pilot study which will recruit patients with brain metastases receiving ICI delivered within 30 days before SRS. All patients will be treated with RADREMI dosing, which involves SRS doses of 18 Gy for 0-2 cm lesions, 14 Gy for 2.1-3 cm lesions, and 12 Gy for 3.1-4 cm lesions. All patients will be monitored for six-month symptomatic radiation necrosis (defined as a six-month rate of clinical symptomatology requiring steroid administration and/or operative intervention concomitant with imaging findings consistent with radiation necrosis) and six-month local control. We expect that RADREMI dosing will significantly reduce the symptomatic radiation necrosis rate of concomitant SRS + ICI without significantly sacrificing the local control obtained by the present RTOG 90-05 SRS dosing schema. Local control will be defined according to the Response Assessment in Neuro-Oncology (RANO) criteria.

DISCUSSION

This study is the first prospective trial to investigate the safety of dose-reduced SRS in treatment of brain metastases with concomitant ICI. The findings should provide fertile soil for future multi-institutional collaborative efficacy trials of RADREMI dosing for this patient population.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT04047602 (registration date: July 25, 2019).

Impact of Lung Parenchymal-Only Failure on Overall Survival in Early-Stage Lung Cancer Patients Treated With Stereotactic Ablative Radiotherapy

INTRODUCTION

The impact of lung parenchymal-only failure on patient survival after stereotactic ablative body radiotherapy (SABR) for early-stage non-small-cell lung cancer (NSCLC) remains unclear.

PATIENTS AND METHODS

The study population included 481 patients with early-stage NSCLC who were treated with 3- to 5-fraction SABR between 2000 and 2016. The primary study objective was to assess the impact of out-of-field lung parenchymal-only failure (OLPF) on overall survival (OS).

RESULTS

At a median follow-up of 5.9 years, the median OS was 2.7 years for all patients. Patients with OLPF did not have a significantly different OS compared to patients without failure (P = .0952, median OS 4.1 years with failure vs. 2.6 years never failure). Analysis in a 1:1 propensity score-matched cohort for Karnofsky performance status, comorbidity score, and smoking status showed no differences in OS between patients without failure and those with OLPF (P = .8). In subgroup analyses exploring the impact of time of failure on OS, patients with OLPF 6 months or more after diagnosis did not have significantly different OS compared to those without failure, when accounting for immortal time bias (P = .3, median OS 4.3 years vs. 3.5 years never failure). Only 7 patients in our data set experienced failure within 6 months of treatment, of which only 4 were confirmed to be true failures; therefore, limited data are available in our cohort on the impact of OLPF for ≤ 6 months on OS.

CONCLUSION

OLPF after SABR for early-stage NSCLC does not appear to adversely affect OS, especially if occurring at least 6 months after SABR. More studies are needed to understand if OLPF within 6 months of SABR is associated with adverse OS. These data are useful when discussing prognosis of lung parenchymal failures after initial SABR.

Exploiting tumor position differences between deep inspiration and expiration in lung stereotactic body radiation therapy planning

PURPOSE

We demonstrate proof of principle that normal tissue doses can be greatly reduced in lung stereotactic body radiation therapy (SBRT) for mobile tumors, if the delivered dose is split between opposite respiratory states.

METHODS

Patients that underwent 5 fraction lung SBRT at our institution and had deep inspiration breath hold (DIBH) and free breathing 4D computed tomography scans were included. Volumetric modulated arc therapy plans were generated on both respiratory phases and a third composite plan was generated delivering half the dose using the DIBH plan and the other half using the expiratory phase plan for each fraction. Computed tomography scans for the composite plan were fused based on ribs adjacent to the tumor to evaluate the dose volume histogram of critical structures.

RESULTS

Four patients with 4 total tumors had requisite planning scans available. Tumor size was between 0.7 to 2.9 cm and tumor movement 1.4 to 2.9 cm. Median reduction in the chest wall (CW) V30Gy for the composite plan was 74.6% (range 33.7 to 100%), 76.9% (range 32.9 to 100%), and 89.3% (range 69.5 to 100%) compared to the DIBH, expiration phase, and free breathing plans, respectively. Median reduction in CW maximum dose for the composite plan was 23.3% (range 0.27% to 46.4%), 23.5% (range 3.2 to 48.2%), and 23.4% (range 0.27% to 48.4%) compared to the DIBH, expiration phase, and free breathing plans, respectively. Greater reduction in CW maximum dose was observed when patients had no overlap in planning target volumes between DIBH and expiration phases (median reduction 43.9% for no overlap vs 2.7% with overlap). Between all plans, lung V20Gy absolute differences were within 1.3%. For 2 of 4 patients, the composite plan met constraints for 3 fraction SBRT, while standard plans did not.

CONCLUSIONS

We conclude that composite DIBH-expiration SBRT planning has the potential to improve organ at risk sparing.

Isocitrate dehydrogenase 1 mutant glioblastomas demonstrate a decreased rate of pseudoprogression: a multi-institutional experience

BACKGROUND

Pseudoprogression (psPD) represents false radiologic evidence of tumor progression and is observed in some glioblastoma (GBM) patients after postoperative chemoradiation (CRT) with temozolomide (TMZ). The ambiguity of the psPD diagnosis confounds identification of true progression and may lead to unnecessary interventions. The association between psPD and isocitrate dehydrogenase 1 (IDH1) mutational (mut) status is understudied, and its incidence may alter clinical decision making.

METHODS

We retrospectively evaluated 120 patients with IDH1-mut (n = 60) and IDH1-wild-type (IDH-WT; [n = 60]) GBMs who received postoperative CRT with TMZ at 4 academic institutions. Response Assessment in Neuro-Oncology criteria were used to identify psPD rates in routine brain MRIs performed up to 90 days after CRT completion.

RESULTS

Within 90 days of completing CRT, 9 GBM patients (1 [1.7%] IDH1-mut and 8 [13.3%] IDH1-WTs) demonstrated true progression, whereas 17 patients (3 [5%] IDH1-muts and 14 [23.3%] IDH1-WTs) demonstrated psPD (P  =  .004). IDH1-mut GBMs had a lower probability of psPD (hazard ratio: 0.173, 95% CI, 0.047-0.638, P = .008). Among the patients with radiologic signs suggestive of progression (n = 26), psPD was found to be the cause in 3 of 4 (75.0%) of the IDH1-mut GBMs and 14 of 22 (63.6%) of the IDH1-WT GBMs (P = .496). Median overall survival for IDH1-mut and IDH1-WT GBM patients was 40.3 and 23.0 months, respectively (P  < .001).

CONCLUSIONS

IDH1-mut GBM patients demonstrate lower absolute rates of psPD expression. Irrespective of GBM subtype, psPD expression was more likely than true progression within 90 days of completing CRT. Continuing adjuvant treatment for IDH1-mut GBMs is suggested if radiologic progression is suspected during this time interval.

Disease-Related Outcomes and Toxicities of Intensity Modulated Radiation Therapy After Lung-Sparing Pleurectomy for Malignant Pleural Mesothelioma: A Systematic Review

PURPOSE

This review explores the use of intensity modulated radiation therapy (IMRT) after lung-sparing surgery in malignant pleural mesothelioma (MPM). Because severe toxicities have been documented after radiation therapy for MPM, its use remains controversial, especially as modern surgical management has shifted toward lung-sparing pleurectomy/decortication. IMRT is an advanced technique that may allow for safer radiation therapy delivery, but there remains limited data (including no summative data) to support this notion.

METHODS AND MATERIALS

We performed a systematic review evaluating the safety and efficacy of post-pleurectomy IMRT (P-IMRT). A systematic review of PubMed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted for publications of all dates that specifically reported clinical outcomes and/or toxicities of P-IMRT in patients with MPM. Ten original studies were included in this review.

RESULTS

The incidence of grade 3 pneumonitis ranged from 0% to 16%, with all but 2 studies reporting rates below 9%. Grade 4 and 5 pneumonitis were observed in less than 1.5% of cases, except in one publication that used hypofractionated radiation therapy to doses >60 Gy. Crude local failure rates ranged from 19% to 60%, median progression free survival ranged from 12 to 16 months, and median overall survival ranged from 19 to 28 months.

CONCLUSIONS

P-IMRT produces relatively few higher-grade toxicities and has reasonable disease-related outcomes, especially when delivered using conventionally fractionated regimens to doses of 45 to 54 Gy and exercising careful attention to dose constraints during treatment planning. IMRT can thus be considered in well-selected patients in whom adequate survival after pleurectomy is expected. These data also support the initiation of the phase III NRG-LU006 trial of extended pleurectomy/decortication and chemotherapy with or without IMRT.

First report of pulmonary large cell neuroendocrine carcinoma treated with stereotactic body radiation therapy

Introduction

Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is a very rare disease, comprising approximately 3% of lung cancers. Even for Stage I disease, recurrence after resection is common, with a poor five-year overall survival. We present the first report of stereotactic body radiotherapy (SBRT) for pulmonary LCNEC.

Methods

A 54-year-old woman with a left upper lobe pulmonary nodule underwent a wedge resection with thoracoscopic mediastinal lymph node dissection, revealing a 2.3 cm pT1b N0 LCNEC. Approximately one year later, surveillance imaging demonstrated a new left upper lobe PET-avid nodule, resulting in completion left upper lobectomy revealing LCNEC, with 0/6 involved lymph nodes and negative staging studies. The patient subsequently chose surveillance over adjuvant chemotherapy; unfortunately 23 months later imaging revealed an enlarging 0.7 cm nodule adjacent to the previous resection site, despite the patient remaining in good health (KPS = 90). Subsequent restaging demonstrated no evidence of metastatic disease. Due to the morbidity of a third operation in this region, and based on the safety of SBRT for Stage I non small-cell lung cancer, the consensus decision from our thoracic oncology team was to proceed with SBRT as preferred management for presumptive second recurrence of LCNEC. The patient shortly thereafter underwent SBRT (50 Gy in 10 Gy/fraction) to this new nodule, 41 months following initial LCNEC diagnosis.

Results

Four months following SBRT, the patient remains in excellent clinical condition (KPS 90), with no evidence of disease spread on surveillance studies. The nodule itself demonstrated no evidence of growth following SBRT.

Conclusions

This first report of SBRT for pulmonary LCNEC demonstrates that SBRT is a feasible modality for this rare disease. A multidisciplinary thoracic oncology approach involving medical oncology, thoracic surgery, radiation oncology and pulmonology is strongly recommended to ensure proper patient selection for receipt of SBRT.

Preoperative platelet counts and postoperative outcomes in cancer surgery: a multicenter, retrospective cohort study

Platelets play roles in malignancy, wound healing, and immunity. Nevertheless, their significance in postoperative outcomes is not established. This is a retrospective cohort study of 100,795 patients undergoing cancer surgery in 2010 and 2014 in >500 hospitals. Patients were stratified into five groups based on preoperative platelet counts. Multivariable logistic regression was used to determine the risk of 30-day mortality, morbidities, readmission, and prolonged hospitalization using the mid-normal group as a reference. We adjusted for demographic variables, comorbidities, and operation complexity. In the 2014 cohort, multivariable analysis showed that mortality was higher in patients with thrombocytopenia (OR 1.49, 95% CI [1.23-1.81]), high-normal platelets (OR 1.29, [1.06-1.55]), and thrombocytosis (OR 1.78, [1.45-2.19]). Composite postoperative morbidity followed a similar trend with thrombocytopenia (OR 1.34, [1.25-1.43]), high-normal counts (OR 1.41, [1.33-1.49]), and thrombocytosis (OR 2.20, [2.05-2.36]). Concordantly, the risks of prolonged hospitalization and 30-day readmission followed the same pattern. These results were validated in a large colon cancer cohort from the 2010 database. In conclusion, platelet count is a prognostic indicator in cancer surgeries. This could be related to the role of platelets in wound healing and immunity on one hand, and propagating malignancy on the other.

Predictors of Nodal and Metastatic Failure in Early Stage Non-small-cell Lung Cancer After Stereotactic Body Radiation Therapy

INTRODUCTION/BACKGROUND

Many patients with early stage non-small-cell lung cancer (ES-NSCLC) undergoing stereotactic body radiation therapy (SBRT) develop metastases, which is associated with poor outcomes. We sought to identify factors predictive of metastases after lung SBRT and created a risk stratification tool.

MATERIALS AND METHODS

We included 363 patients with ES-NSCLC who received SBRT; the median follow-up was 5.8 years. The following patient and tumor factors were retrospectively analyzed for their association with metastases (defined as nodal and/or distant failure): gender; age; lobe involved; centrality; previous NSCLC; smoking status; gross tumor volume (GTV); T-stage; histology; dose; minimum, maximum, and mean GTV dose; and parenchymal lung failure. A metastasis risk-score linear-model using beta coefficients from a multivariate Cox model was built.

RESULTS

A total of 111 (27.3%) of 406 lesions metastasized. GTV and dose were significantly associated with metastases on univariate and multivariate Cox proportional hazards modeling (P < .001 and hazard ratio [HR], 1.02 per mL; P < .05 and HR, 0.99 per Gy, respectively). Histology, T-stage, centrality, lung parenchymal failures, and previous NSCLC were not associated with development of metastasis. A metastasis risk-score model using GTV and prescription dose was built: risk score = (0.01611 × GTV) - (0.00525 × dose [BED₁₀]). Two risk-score cutoffs separating the cohort into low-, medium-, and high-risk subgroups were examined. The risk score identified significant differences in time to metastases between low-, medium-, and high-risk patients (P < .001), with 3-year estimates of 81.1%, 63.8%, and 38%, respectively.

CONCLUSION

GTV and radiation dose are associated with time to metastasis and may be used to identify patients at higher risk of metastasis after lung SBRT.

Histology, Tumor Volume, and Radiation Dose Predict Outcomes in NSCLC Patients After Stereotactic Ablative Radiotherapy

INTRODUCTION

It remains unclear if histology should be independently considered when choosing stereotactic ablative body radiotherapy dose prescriptions for NSCLC.

METHODS

The study population included 508 patients with 561 lesions between 2000 and 2016, of which 442 patients with 482 lesions had complete dosimetric information. Eligible patients had histologically or clinically diagnosed early-stage NSCLC and were treated with 3 to 5 fractions. The primary endpoint was in-field tumor control censored by either death or progression. Involved lobe control was also assessed.

RESULTS

At 6.7 years median follow-up, 3-year in-field control, involved lobe control, overall survival, and progression-free survival rates were 88.1%, 80.0%, 49.4%, and 37.2%, respectively. Gross tumor volume (GTV) (hazard ratio [HR] = 1.01 per mL, p = 0.0044) and histology (p = 0.0225) were independently associated with involved lobe failure. GTV (HR = 1.013, p = 0.001) and GTV dose (cutoff of 110 Gy, biologically effective dose with α/β = 10 [BED10], HR = 2.380, p = 0.0084) were independently associated with in-field failure. For squamous cell carcinomas, lower prescription doses were associated with worse in-field control (12 Gy × 4 or 10 Gy × 5 versus 18 Gy or 20 Gy × 3: HR = 3.530, p = 0.0447, confirmed by propensity score matching) and was independent of GTV (HR = 1.014 per mL, 95% confidence interval: 1.005-1.022, p = 0.0012). For adenocarcinomas, there were no differences in in-field control observed using the above dose groupings (p = 0.12 and p = 0.31, respectively).

CONCLUSIONS

In the absence of level I data, GTV and histology should be considered to personalize radiation dose for stereotactic ablative body radiotherapy. We suggest lower prescription doses (i.e., 12 Gy × 4 or 10 G × 5) should be avoided for squamous cell carcinomas if normal tissue tolerances are met.

The dosimetric differences in calculating lung SBRT plans on different image data sets: Comparison of the free breathing scan to both the average intensity projection scan and to the sum of calculations on each respiratory phase of the 4DCT scan

The purpose of this study is to evaluate the dosimetric differences to the lung internal target volume (ITV) in stereotactic body radiation therapy (SBRT) when calculated on the free breathing (FB) scan in comparison to calculations on the average intensity projection (AIP) scan as well as the sum of dose calculated on each of the treated respiratory phases. The clinical treatment plan data for 16 SBRT lung patients were retrospectively chosen for this study, 5 of which were 30% to 70% respiratory phase gated. All patients had ITV contours and fixed monitor units from the treatment approved plan copied over to each scan on which calculations were to be made. The results of this study yielded 6 out of 16 patients with greater than or equal to 2% difference in ITV maximum dose (D₀) and 2 of 16 patients with greater than or equal to 2% difference in ITV minimum dose (D₁₀₀). The range of ITV dose differences for these 8 patients was 2% to 4.7% with no patients exceeding a 5% difference in D₀ or D₁₀₀. None of the patients had greater than or equal to 2% difference in ITV mean dose (D_mean). Sixty-three percent of patients with greater than 2% ITV dose difference in any of the categories reviewed were those patients with greater than 1 cm gross tumor motion. This study concluded that in order to reduce uncertainty in dose to the ITV, tumor motion should be assessed at simulation and limited to below 1 cm in any direction if possible.

Toxicity of Radiosurgery for Brainstem Metastases

BACKGROUND

Although stereotactic radiosurgery (SRS) is an effective modality in the treatment of brainstem metastases (BSM), radiation-induced toxicity remains a critical concern. To better understand how severe or life-threatening toxicity is affected by the location of lesions treated in the brainstem, a review of all available studies reporting SRS treatment for BSM was performed.

METHODS

Twenty-nine retrospective studies investigating SRS for BSM were reviewed.

RESULTS

The rates of grade 3 or greater toxicity, based on the Common Terminology Criteria for Adverse Events, varied from 0 to 9.5% (mean 3.4 ± 2.9%). Overall, the median time to toxicity after SRS was 3 months, with 90% of toxicities occurring before 9 months. A total of 1243 cases had toxicity and location data available. Toxicity rates for lesions located in the medulla were 0.8% (1/131), compared with midbrain and pons, respectively, 2.8% (8/288) and 3.0% (24/811).

CONCLUSIONS

Current data suggest that brainstem substructure location does not predict for toxicity and lesion volume within this cohort with median tumor volumes 0.04-2.8 cc does not predict for toxicity.

TERT Promoter Mutation Detection in Cell-Free Tumor-Derived DNA in Patients with IDH Wild-Type Glioblastomas: A Pilot Prospective Study

Purpose: We conducted a pilot study to assess the feasibility and the potential implications of detecting TERT promoter (TERTp)-mutant cell-free tumor-derived DNA (tDNA) in the cerebrospinal fluid (CSF) and plasma of glioblastoma patients.Experimental Design: Matched CSF and plasma samples were collected in 60 patients with glial tumors. The CSF collection was obtained during surgery, before any surgical manipulation of the tumor. The extracted tDNA and corresponding tumor DNA samples were analyzed for TERTp and isocitrate dehydrogenase (IDH) hotspot mutations. In addition, the variant allele frequency (VAF) of TERTp mutation in the CSF-tDNA was correlated with tumor features and patients' outcome.Results: Thirty-eight patients had TERTp-mutant/IDH wild-type glioblastomas. The matched TERTp mutation in the CSF-tDNA was successfully detected with 100% specificity (95% CI, 87.6-100%) and 92.1% sensitivity (95% CI, 78.6-98.3%) (n = 35/38). In contrast, the sensitivity in the plasma-tDNA was far lower [n = 3/38, 7.9% (95% CI, 1.6-21.4%)]. We concordantly observed a longer overall survival of patients with low VAF in the CSF-tDNA when compared with patients with high VAF, irrespective of using the lower quartile VAF [11.45%; 14.0 mo. (95% confidence interval, CI, 10.3-17.6) vs. 8.6 mo. (95% CI, 4.1-13.2), P = 0.035], the lower third VAF [13%; 15.4 mo. (95% CI, 11.6-19.2) vs. 8.3 mo. (95% CI, 2.3-14.4), P = 0.008], or the median VAF [20.3%; 14.0 mo. (95% CI, 9.2-18.7) vs. 8.6 mo. (95% CI, 7.5-9.8), P = 0.062] to dichotomize the patients.Conclusions: This pilot study highlights the value of CSF-tDNA for an accurate and reliable detection of TERTp mutations. Furthermore, our findings suggest that high TERTp mutation VAF levels in the CSF-tDNA may represent a suitable predictor of poor survival in glioblastoma patients. Further studies are needed to complement the findings of our exploratory analysis. Clin Cancer Res; 24(21); 5282-91. ©2018 AACR.

Chemoradiotherapy versus chemotherapy alone for unresected intrahepatic cholangiocarcinoma: practice patterns and outcomes from the national cancer data base

Background

Current guidelines recommend chemotherapy (CT) with or without radiotherapy (RT) for unresected intrahepatic cholangiocarcinoma (IC). Although there is currently lack of consensus, previous smaller studies have illustrated the efficacy of local therapy for this population. This investigation evaluated outcomes of chemoradiotherapy (CRT) versus CT alone in unresected IC using a large, contemporary national database.

Methods

The National Cancer Data Base (NCDB) was queried for primary IC cases (2004-2013) receiving CT alone or CRT. Patients undergoing resection or not receiving CT were excluded, as were those with M1 disease or unknown M classification. Logistic regression analysis ascertained factors associated with CRT administration. Kaplan-Meier analysis evaluated overall survival (OS) between both groups. Cox proportional hazards modeling assessed variables associated with OS.

Results

In total, 2,842 patients were analyzed [n=666 (23%) CRT, n=2,176 (77%) CT]. CRT was less likely delivered at community centers, in more recent time periods (2009-2013), to older patients, and in certain geographic locations. Median OS in the CRT and CT groups were 13.6 vs. 10.5 months, respectively (P<0.001). On multivariate analysis, poorer OS was associated with age, male gender, increased comorbidities, treatment at a community center, and treatment at earlier time periods (2004-2008) (P<0.05 for all). Notably, receipt of CRT independently predicted for improved OS (P<0.001).

Conclusions

As compared to CT alone, CRT was independently associated with improved survival in unresected IC. These findings support a randomized trial evaluating this question that is currently accruing.

In Vitro Cell-free DNA Quantification: A Novel Method to Accurately Quantify Cell Survival after Irradiation

Circulating tumor DNA (ctDNA) analysis has been shown to aid in both the detection of cancer and evaluation of somatic mutations in tumors. CtDNA concentration in plasma increases in proportion to tumor volume and/or metabolic activity and growth; however, this principle has yet to be applied to cell culture. We hypothesized that cell line-specific cell-free DNA (cfDNA) can be used to measure cell viability and cell survival in cell culture. Clonogenic assays on non-small cell lung cancer (NSCLC) cell lines H322, A549 and H322 were exposed to radiation doses of 0, 4 and 8 Gy. Prior to colony fixation and counting, cfDNA was extracted and quantified from cell culture media. The correlation between cell line-specific cfDNA and number of colonies grown on culture plates was examined. An H1299:A549 coculture model was used to evaluate the differential release of cell line-specific cfDNA. The results of this work indicate a strong correlation between CfDNA quantification from cell culture media and clonogenic survival at all radiation doses and in all cell lines tested (R² range = 0.77-0.99). Cell survival curves derived from cfDNA were virtually indistinguishable from matched traditional clonogenic survival data ( P > 0.05; no significant difference exists between clonogenic curves). CfDNA quantification also accurately estimates colony count in a two-cell-line coculture model. In conclusion, cell-free DNA quantification from cell culture media can be used to measure cell survival, and appears suitable for development in a high-throughput clonogenic assay and radiosensitizer screening platform.

Selective bladder preservation with twice-daily radiation plus 5-flourouracil/cisplatin (FCT) or daily radiation plus gemcitabine (GD) for patients with muscle invasive bladder cancer: Primary results of NRG/RTOG 0712—A randomized phase 2 multicenter trial

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Background: To assess GD or FCT as the chemoradiation (CRT) component of a bladder sparing regimen. Methods: Patients with T2-4a bladder cancer were randomized. Patients had a maximal transurethral resection and induction CRT to 40 Gy followed by cystoscopic assessment. Patients with a complete response (CR) received consolidation CRT to 64 Gy. Others were offered cystectomy and no further CRT. Adjuvant gemcitabine/cisplatin chemotherapy was subsequently administered. The primary endpoint was the rate of distant metastasis at 3 years (DM3). Toxicity and other efficacy related endpoints including CR and bladder intact distant metastasis free survival at 3 years (BI-DMFS3) were also assessed. Using the Clopper-Pearson method, the study required 32 patients per arm, with a benchmark DM3 of 25% and a 1-sided significance level of 0.1. If both arms meet this benchmark, toxicity will be used to select a regimen for future study. This study was not designed to compare arms. Results: From 12/2008 to 4/2014, 70 patients were enrolled; 66 were eligible for analysis (33 per arm). Median follow-up was 4.3 years. DM3 was 22% and 16% for FCT and GD, respectively. BI-DMFS3 was 67% and 72%, respectively. CR rates were 88% and 78%, respectively. Of 33 patients in the FCT group, 32 (97%) completed induction, 27 (93%) completed induction and consolidation, and 18 (55%) completed the entire protocol. Of 33 patients in the GD group, these figures were 31 (94%), 23 (92%), and 16 (49%), respectively. Of 33 patients in the FCT group, 21 (64%) had grade 3-4 toxicity during protocol treatment with 18 (55%), 2 (6%) and 2 (6%) experiencing hematologic, GI and GU toxicity, respectively. For 33 patients in the GD group, these figures were 18 (55%) overall and 14 (43%), 3 (9%) and 2 (6%), respectively. Conclusions: Both regimens are promising, given DM3 rates < 25%. As there was less toxicity in the GD arm, it would be reasonable to consider a gemcitabine based option as well as a cisplatin based regimen for future trials. Daily radiation may be as effective as twice-daily radiation, which may broaden appeal. Clinical trial information: NCT00777491.

Brainstem metastases treated with Gamma Knife stereotactic radiosurgery: the Indiana University Health experience

Brainstem metastases offer a unique challenge in cancer treatment, yet stereotactic radiosurgery (SRS) has proven to be an effective modality in treating these tumors. This report discusses the clinical outcomes of patients with brainstem metastases treated at Indiana University with Gamma Knife (GK) radiosurgery from 2008 to 2016. 19 brainstem metastases from 14 patients who had follow-up brain imaging were identified. Median tumor volume was 0.04 cc (range: 0.01–2.0 cc). Median prescribed dose was 17.5 Gy to the 50% isodose line (range: 14–22 Gy). Median survival after GK SRS treatment to brainstem lesion was 17.2 months (range: 2.8–45.6 months). The experience at Indiana University confirms the safety and efficacy of range of GK SRS prescription doses (14–22 Gy) to brainstem metastases.

Blood-based biomarkers for precision medicine in lung cancer: precision radiation therapy

Both tumors and patients are complex and models that determine survival and toxicity of radiotherapy or any other treatment ideally must take into account this variability as well as its dynamic state. The genetic features of the tumor and the host, and increasingly also the epi-genetic and proteomic characteristics, are being unraveled. Multiple techniques, including histological examination, blood sampling, measurement of circulating tumor cells (CTCs), and functional and molecular imaging, can be used for this purpose. However, the effects of radiation on the tumor and on organs at risk (OARs) are also influenced by the applied dose and volume of irradiated tissues. Combining all these biological, clinical, imaging, and dosimetric parameters in a validated prognostic or predictive model poses a major challenge. Here we aimed to provide an objective review of the potential of blood markers to guide high precision radiation therapy. A combined biological-mathematical approach opens new doors beyond prognostication of patients, as it allows truly precise oncological treatment. Indeed, the core for individualized and precision medicine is not only selection of patients, but even more the optimization of the therapeutic window on an individual basis. A holistic model will allow for determination of an individual dose-response relationship for each organ at risk for each tumor in each individual patient for the complete oncological treatment package. This includes, but is not limited to, radiotherapy alone. Individualized dose-response curves will allow for consideration of different doses of radiation and combinations with other drugs to plan for both optimal toxicity and complete response. Insights into the interactions between a multitude of parameters will lead to the discovery of new pathways and networks that will fuel new biological research on target discovery.