Metformin use and improved response to therapy in esophageal adenocarcinoma.

BACKGROUND: We investigated the radiographic and pathologic response rate of esophageal adenocarcinoma treated with neoadjuvant chemoradiation in patients taking metformin. MATERIAL AND METHODS: Two hundred eighty-five patients with esophageal adenocarcinoma treated with concurrent chemoradiation (CRT) followed by esophagectomy from 1997 to 2012 were included in the study, including 29 diabetics taking metformin, 21 diabetics not taking metformin and 235 non-diabetics. Pre- and post-treatment positron emission tomography (PET) scans were available for 204 patients. Pathologic response was graded at the time of surgery. Response rates were compared using both the χ(2) statistic as well as ANOVA with post-hoc LSD analysis. Multivariate logistic regression analysis was performed to control for predictors of pathologic complete response (CR) after CRT. RESULTS: The overall rate of pathologic CR for the study population was 20%. The pathologic CR rate was higher in patients taking metformin (34.5%), compared to diabetic patients not taking metformin (4.8%, p = 0.01) and non-diabetic patients (19.6%, p = 0.05). Pathologic CR was related to metformin dose, with ≥ 1500 mg/d associated with a higher CR rate. No significant difference seen in pre-CRT maximum tumor SUV (p = 0.93), however post-CRT maximum SUV was significantly decreased in patients taking metformin (p = 0.05). On multivariate logistic regression, metformin use was independently associated with pathologic CR (p = 0.04). Metformin use was also associated with decreased in field loco-regional failure following radiation (p = 0.05). CONCLUSION: Metformin use is associated with a dose-dependent increased response to CRT in esophageal cancer and may be a sensitizer to this therapy.

A prospective phase 2 study of surgery followed by chemotherapy and radiation for superior sulcus tumors.

BACKGROUND: The optimal treatment for locally advanced superior sulcus tumors is not clear. The authors report long-term results of a trial examining the safety and efficacy of surgery followed by concurrent chemoradiation therapy for this disease. METHODS: Thirty-two patients with resectable or marginally resectable superior sulcus tumors at The University of Texas MD Anderson Cancer Center from 1994 to 2010 were enrolled in a prospective trial. Surgery involved segmentectomy or lobectomy with en bloc resection of the involved chest wall and complete nodal staging; radiation therapy (RT) began 14 to 42 days later to a dose of 60 grays (Gy) in 50 1.2-Gy fractions if surgical margins were negative or 64.8 Gy in 54 1.2-Gy fractions if margins were positive. Two cycles of etoposide (50 mg/m(2) ) and cisplatin (50 mg/m(2) ) were given during RT, and another 3 cycles were given after RT. Eleven patients underwent prophylactic cranial irradiation (PCI). RESULTS: The protocol completion rate was 78%. Gross total resection was accomplished in all 32 patients; 28% underwent R1 resection. Operative mortality was 0%. The most common surgical complication was postoperative pneumonia (25%). At a median follow-up time of 53.4 months (range, 2-154 months), the 2-year, 5-year, and 10-year rates of locoregional control were 84%, 76%, and 76%; distant metastasis-free survival, 52%, 48%, and 48%; disease-free survival, 49%, 45%, and 45%; and overall survival, 72%, 50%, and 45%, respectively. The brain was the most common site of distant failure (n = 5), but no patient who received PCI experienced brain metastasis. CONCLUSIONS: Surgery followed by postoperative chemoradiation is safe and effective for the treatment of marginally resectable superior sulcus tumors.

Phase 2 study of high-dose proton therapy with concurrent chemotherapy for unresectable stage III nonsmall cell lung cancer.

BACKGROUND: The authors sought to improve the toxicity of conventional concurrent chemoradiation therapy for stage III nonsmall cell lung cancer (NSCLC) by using proton-beam therapy to escalate the radiation dose to the tumor. They report early results of a phase 2 study of high-dose proton therapy and concurrent chemotherapy in terms of toxicity, failure patterns, and survival. METHODS: Forty-four patients with stage III NSCLC were treated with 74 grays (radiobiologic equivalent) proton therapy with weekly carboplatin (area under the curve, 2 U) and paclitaxel (50 mg/m(2)). Disease was staged with positron emission tomography/computed tomography (CT), and treatments were simulated with 4-dimensional (4D) CT to account for tumor motion. Protons were delivered as passively scattered beams, and treatment simulation was repeated during the treatment process to determine the need for adaptive replanning. RESULTS: Median follow-up time was 19.7 months (range, 6.1-44.4 months), and median overall survival time was 29.4 months. No patient experienced grade 4 or 5 proton-related adverse events. The most common nonhematologic grade 3 toxicities were dermatitis (n = 5), esophagitis (n = 5), and pneumonitis (n = 1). Nine (20.5%) patients experienced local disease recurrence, but only 4 (9.1%) had isolated local failure. Four (9.1%) patients had regional lymph node recurrence, but only 1 (2.3%) had isolated regional recurrence. Nineteen (43.2%) patients developed distant metastasis. The overall survival and progression-free survival rates were 86% and 63% at 1 year. CONCLUSIONS: Concurrent high-dose proton therapy and chemotherapy are well tolerated, and the median survival time of 29.4 months is encouraging for unresectable stage III NSCLC.

Early findings on toxicity of proton beam therapy with concurrent chemotherapy for nonsmall cell lung cancer.

BACKGROUND: Concurrent chemoradiation therapy, the standard of care for locally advanced nonsmall cell lung cancer (NSCLC), can cause life-threatening pneumonitis and esophagitis. X-ray (photon)-based radiation therapy (RT) often cannot be given at tumoricidal doses without toxicity to proximal normal tissues. We hypothesized that proton beam therapy for most patients with NSCLC could permit higher tumor doses with less normal-tissue toxicity than photon RT delivered as 3-dimensional conformal RT (3D-CRT) or intensity-modulated RT (IMRT). METHODS: We compared the toxicity of proton therapy+concurrent chemotherapy in 62 patients with NSCLC (treatment period 2006-2008) with toxicity for patients with similar disease given 3D-CRT+chemotherapy (n = 74; treatment period 2001-2003) or IMRT+chemotherapy (n = 66; treatment period 2003-2005). Proton therapy to the gross tumor volume was given with weekly intravenous paclitaxel (50 mg/m²) and carboplatin (area under the curve 2 mg/mL/min). The primary endpoint was toxicity (Common Terminology Criteria for Adverse Events version 3.0). RESULTS: Median follow-up times were 15.2 months (proton), 17.9 months (3D-CRT), and 17.4 months (IMRT). Median total radiation dose was 74 Gy(RBE) for the proton group versus 63 Gy for the other groups. Rates of severe (grade ≥ 3) pneumonitis and esophagitis in the proton group (2% and 5%) were lower despite the higher radiation dose (3D-CRT, 30% and 18%; IMRT, 9% and 44%; P<.001 for all). CONCLUSIONS: We found that higher doses of proton radiation could be delivered to lung tumors with a lower risk of esophagitis and pneumonitis. A randomized comparison of IMRT versus proton therapy is underway.

Status of particle therapy for lung cancer.

The current standard treatment for lung cancer, the most common type of cancer worldwide, depends on disease stage. Surgery is the treatment of choice for early-stage tumors, but radiotherapy is a good option for those with early-stage tumors who cannot undergo surgery, and radiotherapy in conjunction with chemotherapy is the standard of care for locally advanced tumors. Although advances in photon (x-ray)-based radiotherapy involving three-dimensional conformal radiotherapy and intensity-modulated radiotherapy allow radiation doses to be escalated beyond the traditional limit of 60 Gy, this dose is not considered to be sufficient for tumor eradication. Moreover, the improvements in local control and survival conferred by concurrent chemotherapy come at the cost of considerable toxicity owing to inadvertent irradiation of surrounding normal tissues, and this toxicity often limits the radiation dose that can be delivered. Unfortunately for patients with locally advanced lung cancer, local control and survival remain poor. Attempts to improve clinical outcomes for patients with lung cancer have led to the use of charged particle therapy in an effort to exploit the physical properties of such particles to escalate the dose to the tumor while simultaneously limiting the dose to nearby structures, thereby enhancing the therapeutic ratio and potentially improving cancer cure rates. This review summarizes the rationale for and challenges associated with the use of charged particles for lung cancer therapy and reviews the clinical experience to date with using protons and carbon ions for early-stage and locally advanced stage non-small cell lung cancer.

Radiotherapy plus chemotherapy with or without surgical resection for stage III non-small-cell lung cancer: a phase III randomised controlled trial.

BACKGROUND: Results from phase II studies in patients with stage IIIA non-small-cell lung cancer with ipsilateral mediastinal nodal metastases (N2) have shown the feasibility of resection after concurrent chemotherapy and radiotherapy with promising rates of survival. We therefore did this phase III trial to compare concurrent chemotherapy and radiotherapy followed by resection with standard concurrent chemotherapy and definitive radiotherapy without resection. METHODS: Patients with stage T1-3pN2M0 non-small-cell lung cancer were randomly assigned in a 1:1 ratio to concurrent induction chemotherapy (two cycles of cisplatin [50 mg/m(2) on days 1, 8, 29, and 36] and etoposide [50 mg/m(2) on days 1-5 and 29-33]) plus radiotherapy (45 Gy) in multiple academic and community hospitals. If no progression, patients in group 1 underwent resection and those in group 2 continued radiotherapy uninterrupted up to 61 Gy. Two additional cycles of cisplatin and etoposide were given in both groups. The primary endpoint was overall survival (OS). Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00002550. FINDINGS: 202 patients (median age 59 years, range 31-77) were assigned to group 1 and 194 (61 years, 32-78) to group 2. Median OS was 23.6 months (IQR 9.0-not reached) in group 1 versus 22.2 months (9.4-52.7) in group 2 (hazard ratio [HR] 0.87 [0.70-1.10]; p=0.24). Number of patients alive at 5 years was 37 (point estimate 27%) in group 1 and 24 (point estimate 20%) in group 2 (odds ratio 0.63 [0.36-1.10]; p=0.10). With N0 status at thoracotomy, the median OS was 34.4 months (IQR 15.7-not reached; 19 [point estimate 41%] patients alive at 5 years). Progression-free survival (PFS) was better in group 1 than in group 2, median 12.8 months (5.3-42.2) vs 10.5 months (4.8-20.6), HR 0.77 [0.62-0.96]; p=0.017); the number of patients without disease progression at 5 years was 32 (point estimate 22%) versus 13 (point estimate 11%), respectively. Neutropenia and oesophagitis were the main grade 3 or 4 toxicities associated with chemotherapy plus radiotherapy in group 1 (77 [38%] and 20 [10%], respectively) and group 2 (80 [41%] and 44 [23%], respectively). In group 1, 16 (8%) deaths were treatment related versus four (2%) in group 2. In an exploratory analysis, OS was improved for patients who underwent lobectomy, but not pneumonectomy, versus chemotherapy plus radiotherapy. INTERPRETATION: Chemotherapy plus radiotherapy with or without resection (preferably lobectomy) are options for patients with stage IIIA(N2) non-small-cell lung cancer. FUNDING: National Cancer Institute, Canadian Cancer Society, and National Cancer Institute of Canada.

Evaluating quality in clinical cancer research: the M.D. Anderson Cancer Center experience.

BACKGROUND: Despite the unquestionable importance of clinically oriented research designed to test the safety and efficacy of new therapies in patients with malignant disease, there is limited information regarding strategies to evaluate the quality of such efforts at academic institutions. METHODS: To address this issue, a committee of senior faculty at the University of Texas M.D. Anderson Cancer Center established specific criteria by which investigators from all departments engaged in clinical research could be formally evaluated. Scoring criteria were established and revised based on the results of a pilot study. Beginning in January 2004, the committee evaluated all faculty involved in clinical research within 35 departments. Scores for individual faculty members were assigned on a scale of 1 (outstanding) to 5; a score of 3 was set as the standard for the institution. Each department also received a score. The results of the evaluation were shared with departmental chairs and the Chief Academic Officer. RESULTS: 392 faculty were evaluated. The median score was 3. Full professors more frequently received a score of 1, but all faculty ranks received scores of 4 and 5. As a group, tenure/tenure track faculty achieved superior scores compared to nontenure track faculty. CONCLUSIONS: Based on our experience, we believe it is possible to conduct a rigorous consensus-based evaluation of the quality of clinical cancer research being conducted at an academic medical center. It is reasonable to suggest such evaluations can be used as a management tool and may lead to higher-quality clinical research.

Radiation dosimetry and biodistribution of (99m)Tc-ethylene dicysteine-deoxyglucose in patients with non-small-cell lung cancer.

PURPOSE: To assess the radiation dosimetry and biodistribution of (99m)Tc-labeled ethylene dicysteine deoxyglucose ((99m)Tc-EC-DG) in patients with non-small-cell lung cancer (NSCLC). METHODS: Serial whole-body scans were acquired 0, 2, 4, 6 and 24 h after injection of (99m)Tc-EC-DG (925 MBq) in seven NSCLC patients. Radiation dosimetry, blood clearance and SPECT imaging of the primary tumor were assessed. RESULTS: The critical organ was the bladder wall, with average radiation absorbed dose over all seven patients of 2.47x10(-2) mGy/MBq. The average effective dose equivalent and effective dose were 6.20x10(-3) mSv/MBq (6.89 mSv/1,110 MBq) and 5.90x10(-3) mSv/MBq (6.54 mSv/1,110 MBq), respectively. The primary tumor was visualized with SPECT in six patients. On final pathology, one patient had a granuloma, which did not enhance with (99m)Tc-EC-DG. CONCLUSION: (99m)Tc-EC-DG has acceptable dosimetric and biodistribution properties as a diagnostic tumor-imaging agent. Future studies are planned to evaluate its diagnostic potential.

The risk of developing a second cancer after receiving craniospinal proton irradiation.

The purpose of this work was to compare the risk of developing a second cancer after craniospinal irradiation using photon versus proton radiotherapy by means of simulation studies designed to account for the effects of neutron exposures. Craniospinal irradiation of a male phantom was calculated for passively-scattered and scanned-beam proton treatment units. Organ doses were estimated from treatment plans; for the proton treatments, the amount of stray radiation was calculated separately using the Monte Carlo method. The organ doses were converted to risk of cancer incidence using a standard formalism developed for radiation protection purposes. The total lifetime risk of second cancer due exclusively to stray radiation was 1.5% for the passively scattered treatment versus 0.8% for the scanned proton beam treatment. Taking into account the therapeutic and stray radiation fields, the risk of second cancer from intensity-modulated radiation therapy and conventional radiotherapy photon treatments were 7 and 12 times higher than the risk associated with scanned-beam proton therapy, respectively, and 6 and 11 times higher than with passively scattered proton therapy, respectively. Simulations revealed that both passively scattered and scanned-beam proton therapies confer significantly lower risks of second cancers than 6 MV conventional and intensity-modulated photon therapies.

Prognostic Significance of Total Lymphocyte Count, Neutrophil-to-lymphocyte Ratio, and Platelet-to-lymphocyte Ratio in Limited-stage Small-cell Lung Cancer.

BACKGROUND: We sought reliable markers of survival and disease control among patients treated for limited-stage small-cell lung cancer (LS-SCLC). PATIENTS AND METHODS: Subjects were 122 patients given (chemo)radiotherapy for LS-SCLC at MD Anderson in 2002 through 2015. Pretreatment total lymphocyte count (TLC), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) were analyzed for associations with overall (OS) and progression-free survival. Optimal cutoff values were identified with receiver operating characteristic curves and survival probabilities with the Kaplan-Meier method. RESULTS: Pretreatment TLC was 1.86 × 103/µL (±0.88); NLR, 3.44 (±3.69); and PLR, 170.53 (±101.56); corresponding cutoffs were 1.9, 2.9, and 140.1. Higher TLC was associated with superior median and 2-year OS (17.4 vs. 15.7 months and 33% vs. 29%; P = .029), and higher NLR and PLR with worse median and 2-year OS (NLR: 14.9 vs. 17.8 months, 29% vs. 31%; P = .026; PLR: 14.8 vs. 18.9 months, 24% vs. 37%; P = .009). Multivariate Cox regression adjusted for age, disease stage, number of chemotherapy cycles, and use of prophylactic cranial irradiation confirmed the links between high TLC and superior OS (hazard ratio [HR] 0.55; 95% confidence interval [CI], 0.32-0.94; P = .028) and between high NLR and PLR and inferior OS (NLR: HR, 1.86; 95% CI, 1.15-3.01; P = .011; PLR: HR, 1.72; 95% CI, 1.06-2.82; P = .030). CONCLUSIONS: Baseline lymphopenia was an indicator of poor prognosis in patients with LS-SCLC.

Radiation therapy for cancer. The fifteenth anniversary of Hiroshima Cancer Seminar Foundation, the Seventeenth International Symposium of Hiroshima Cancer Seminar, November 2007.

This symposium presented what we do to really know about new technology for radiation therapy and what we do to realize our final goal of selective radiation therapy and CRT for cancer. It no doubt provided us for a great deal of information on technological and conceptual advances in radiation therapy and radiation biology.

Utility of four-dimensional computed tomography for analysis of intrafractional and interfractional variation in lung volumes.

PURPOSE: To assess the viability of four-dimensional (4D) computed tomography (CT) in describing intrafractional and interfractional changes in lung volumes and to determine which breathing phase, if any, produces the most highly reproducible lung volumes among fractions. METHODS AND MATERIALS: Weekly 4D CT scans were acquired for 13 patients with non-small-cell lung cancer during a course of radiotherapy. Contours delineating the right lung, left lung, and total lung were obtained by adapting library models of the anatomic structures to the CT images and propagating them to all 10 respiratory phases represented in the 4D CT image data set. Lung volumes were calculated using software tools in a commercial radiation treatment-planning system and analyzed for interfractional volume reproducibility using t tests and for phase reproducibility using a phase-dependent uncertainty curve across all patients. Probability (p) values of <0.05 were considered to indicate significant differences in all comparisons. RESULTS: The average mean coefficient of variation of tidal volume across all patients was 25.0%. The average standard deviation of tidal volumes was 5.7% relative to the lung volume at end-expiration. Total volumes measured at the 30% phase were 15% more consistent than those measured at end-inspiration (p = 0.03). CONCLUSIONS: Four-dimensional CT assesses lung volume with acceptable precision; but the technique was unable to accurately predict interfractional changes in lung volume because wide variations in intra- and interfractional breathing cause high uncertainties in 4D CT data acquisition. The most reproducible breathing phase seems to be at the 30-40% phase (just before end-expiration).

Risk factors for pericardial effusion in inoperable esophageal cancer patients treated with definitive chemoradiation therapy.

PURPOSE: To identify clinical and dosimetric factors influencing the risk of pericardial effusion (PCE) in patients with inoperable esophageal cancer treated with definitive concurrent chemotherapy and radiation therapy (RT). METHODS AND MATERIALS: Data for 101 patients with inoperable esophageal cancer treated with concurrent chemotherapy and RT from 2000 to 2003 at our institution were analyzed. The PCE was confirmed from follow-up chest computed tomography scans and radiologic reports, with freedom from PCE computed from the end of RT. Log-rank tests were used to identify clinical and dosimetric factors influencing freedom from PCE. Dosimetric factors were calculated from the dose-volume histogram for the whole heart and pericardium. RESULTS: The crude rate of PCE was 27.7% (28 of 101). Median time to onset of PCE was 5.3 months (range, 1.0-16.7 months) after RT. None of the clinical factors investigated was found to significantly influence the risk of PCE. In univariate analysis, a wide range of dose-volume histogram parameters of the pericardium and heart were associated with risk of PCE, including mean dose to the pericardium, volume of pericardium receiving a dose greater than 3 Gy (V3) to greater than 50 Gy (V50), and heart volume treated to greater than 32-38 Gy. Multivariate analysis selected V30 as the only parameter significantly associated with risk of PCE. CONCLUSIONS: High-dose radiation to the pericardium may strongly increase the risk of PCE. Such a risk may be reduced by minimizing the dose-volume of the irradiated pericardium and heart.

Daily bone alignment with limited repeat CT correction rivals daily ultrasound alignment for prostate radiotherapy.

PURPOSE: To compare the effectiveness of daily ultrasound (US)- and computed tomography (CT)-guided alignments with an off-line correction protocol using daily bone alignment plus a correction factor for systematic internal prostate displacement (CF(ID)). METHODS AND MATERIALS: Ten prostate cancer patients underwent CT scans three times weekly using an integrated CT-linear accelerator system, followed by alignment using US for daily radiotherapy. Intensity-modulated radiotherapy plans were designed with our current clinical margins. The treatment plan was copied onto the repeat CT images and aligned using several methods: (1) bone alignment plus CF(ID) after three off-line CT scans (bone+3CT), (2) bone alignment plus CF(ID) after six off-line CT scans (bone+6CT), (3) US alignment, and (4) CT alignment. The accuracy of the repeated US and CT measurements to determine the CF(ID) was compared. The target dosimetric effect was quantified. RESULTS: The CF(ID) for internal systematic prostate displacements was more accurately measured with limited repeat CT scans than with US (residual error, 0.0 +/- 0.7 mm vs. 2.0 +/- 3.2 mm). Bone+3CT, bone+6CT, and US provided equivalent prostate and seminal vesicle dose coverage, but bone+3CT and bone+6CT produced more precise daily alignments. Daily CT alignment provided the greatest target dose coverage. CONCLUSION: Daily bone alignment plus CF(ID) for internal systematic prostate displacement provided better daily alignment precision and equivalent dose coverage compared with daily US alignment. The CF(ID) should be based on at least three repeat CT scans, which could be collected before the start of treatment or during the first 3 treatment days. Daily bone alignment plus CF(ID) provides another option for accurate prostate cancer patient positioning.

Four-dimensional computed tomography-based treatment planning for intensity-modulated radiation therapy and proton therapy for distal esophageal cancer.

PURPOSE: To compare three-dimensional (3D) and four-dimensional (4D) computed tomography (CT)-based treatment plans for proton therapy or intensity-modulated radiation therapy (IMRT) for esophageal cancer in terms of doses to the lung, heart, and spinal cord and variations in target coverage and normal tissue sparing. METHODS AND MATERIALS: The IMRT and proton plans for 15 patients with distal esophageal cancer were designed from the 3D average CT scans and then recalculated on 10 4D CT data sets. Dosimetric data were compared for tumor coverage and normal tissue sparing. RESULTS: Compared with IMRT, median lung volumes exposed to 5, 10, and 20 Gy and mean lung dose were reduced by 35.6%, 20.5%, 5.8%, and 5.1 Gy for a two-beam proton plan and by 17.4%, 8.4%, 5%, and 2.9 Gy for a three-beam proton plan. The greater lung sparing in the two-beam proton plan was achieved at the expense of less conformity to the target (conformity index [CI], 1.99) and greater irradiation of the heart (heart-V40, 41.8%) compared with the IMRT plan(CI, 1.55, heart-V40, 35.7%) or the three-beam proton plan (CI, 1.46, heart-V40, 27.7%). Target coverage differed by more than 2% between the 3D and 4D plans for patients with substantial diaphragm motion in the three-beam proton and IMRT plans. The difference in spinal cord maximum dose between 3D and 4D plans could exceed 5 Gy for the proton plans partly owing to variations in stomach gas filling. CONCLUSIONS: Proton therapy provided significantly better sparing of lung than did IMRT. Diaphragm motion and stomach gas-filling must be considered in evaluating target coverage and cord doses.

Outcomes of re-irradiation for brain recurrence after prophylactic or therapeutic whole-brain irradiation for small cell lung Cancer: a retrospective analysis.

BACKGROUND: Small cell lung cancer (SCLC) can recur in the brain after whole-brain irradiation (WBI). We documented outcomes after treatment of such recurrences and sought predictors of local control and overall survival (OS). MATERIALS AND METHODS: Eighty-five patients with SCLC and brain recurrence after prophylactic or therapeutic WBI in 1998-2015 were identified and data were extracted from the medical records. Survival was estimated with the Kaplan-Meier method, and univariate and multivariate Cox proportional hazards modeling was used to identify factors associated with OS or further brain progression. RESULTS: Brain recurrence was treated by stereotactic radiosurgery (SRS) in 33 patients (39%), repeat WBI in 14 (16%), chemotherapy-only in 16 (19%), and observation in 22 (26%). Median OS time after brain recurrence (OSrec) was 4.3 months for all patients; 6-month OSrec rates were 58% after SRS, 21% after repeat WBI, 50% after chemotherapy-only, and 5% after observation (P < 0.001). Inferior OSrec was associated with poor performance status (ECOG score ≥ 3) and uncontrolled extracranial disease. Superior OSrec was associated with receipt of ≥4 chemotherapy cycles before brain recurrence and receipt of chemotherapy, SRS, or repeat WBI afterward. Receipt of chemotherapy after brain recurrence correlated with brain progression. CONCLUSIONS: Some patients with brain recurrence after WBI for SCLC can survive for extended periods with appropriate intervention, especially those with adequate performance status or controlled extracranial disease.

Twice-daily Thoracic Radiotherapy for Limited-stage Small-cell Lung Cancer Does Not Increase the Incidence of Acute Severe Esophagitis.

PURPOSE: Acute esophagitis is common after thoracic radiation therapy (TRT) given with chemotherapy for limited-stage small-cell lung cancer (LS SCLC). Although twice-daily TRT to 45 Gy in 30 fractions is considered standard, some clinicians are reluctant to use this schedule because of its perceived impracticality and risk of severe esophagitis. We reviewed a single-institution experience with severe (grade ≥ 3) esophagitis after TRT with chemotherapy for LS SCLC. PATIENTS AND METHODS: A total of 504 patients were identified as having received TRT (≥45 Gy) with platinum-containing chemotherapy for LS SCLC at MD Anderson Cancer Center in 1987 through 2012. Patients with complete or good partial response were offered prophylactic cranial irradiation. Esophagitis was scored retrospectively with the Common Terminology Criteria for Adverse Events, V3.0. Clinical variables were analyzed for possible association with acute grade ≥ 3 esophagitis. RESULTS: At a median follow-up time of 23.9 months (range, 1.2-240.8 months), 103 (20%) patients had experienced grade ≥ 3 esophagitis. In univariate analysis, TRT dose ≥ 60 Gy was the only factor associated with severe esophagitis (odds ratio [OR], 1.84; 95% confidence interval [CI], 1.02-3.30; P = .043); use of twice-daily TRT was not (OR, 0.96; 95% CI, 0.61-1.52; P = .867). The significance of TRT to ≥ 60 Gy was maintained in multivariate Cox regression analysis adjusted for tumor size (OR, 1.91; 95% CI, 1.05-3.46; P = .034). CONCLUSIONS: TRT to ≥ 60 Gy predicted acute severe esophagitis, but twice-daily fractionation did not. Standard-dose 45-Gy twice-daily TRT should not be avoided for fear of severe esophagitis.

Bayesian Adaptive Randomization Trial of Passive Scattering Proton Therapy and Intensity-Modulated Photon Radiotherapy for Locally Advanced Non-Small-Cell Lung Cancer.

Purpose This randomized trial compared outcomes of passive scattering proton therapy (PSPT) versus intensity-modulated (photon) radiotherapy (IMRT), both with concurrent chemotherapy, for inoperable non-small-cell lung cancer (NSCLC). We hypothesized that PSPT exposes less lung tissue to radiation than IMRT and thereby reduces toxicity without compromising tumor control. The primary end points were grade ≥ 3 radiation pneumonitis (RP) and local failure (LF). Patients and Methods Eligible patients had stage IIB to IIIB NSCLC (or stage IV NSCLC with a single brain metastasis or recurrent lung or mediastinal disease after surgery) who were candidates for concurrent chemoradiation therapy. Pairs of treatment plans for IMRT and PSPT were created for each patient. Patients were eligible for random assignment only if both plans satisfied the same prespecified dose-volume constraints for at-risk organs at the same tumor dose. Results Compared with IMRT (n = 92), PSPT (n = 57) exposed less lung tissue to doses of 5 to 10 Gy(RBE), which is the absorbed Gy dose multiplied by the relative biologic effectiveness (RBE) factor for protons; exposed more lung tissue to ≥ 20 Gy(RBE), but exposed less heart tissue at all dose levels between 5 and 80 Gy(RBE). The grade ≥ 3 RP rate for all patients was 8.1% (IMRT, 6.5%; PSPT, 10.5%); corresponding LF rates were 10.7% (all), 10.9% (IMRT), and 10.5% (PSPT). The posterior probability of IMRT being better than PSPT was 0.54. Exploratory analysis showed that the RP and LF rates at 12 months for patients enrolled before versus after the trial midpoint were 21.1% (before) versus 18.2% (after) for the IMRT group (P = .047) and 31.0% (before) versus 13.1% (after) for the PSPT group (P = .027). Conclusion PSPT did not improve dose-volume indices for lung but did for heart. No benefit was noted in RP or LF after PSPT. Improvements in both end points were observed over the course of the trial.

Risk factors for late bowel and bladder toxicities in NRG Oncology prostate cancer trials of high-risk patients: A meta-analysis of physician-rated toxicities.

PURPOSE: A meta-analysis of sociodemographic variables and their association with late (>180 days from start of radiation therapy[RT]) bowel, bladder, and clustered bowel and bladder toxicities was conducted in patients with high-risk (clinical stages T2c-T4b or Gleason score 8-10 or prostate-specific antigen level >20) prostate cancer. METHODS AND MATERIALS: Three NRG trials (RTOG 9202, RTOG 9413, and RTOG 9406) that accrued from 1992 to 2000 were used. Late toxicities were measured with the Radiation Therapy Oncology Group Late Radiation Morbidity Scale. After controlling for study, age, Karnofsky Performance Status, and year of accrual, sociodemographic variables were added to the model for each outcome variable of interest in a stepwise fashion using the Fine-Gray regression models with an entry criterion of 0.05. RESULTS: A total of 2432 patients were analyzed of whom most were Caucasian (76%), had a KPS score of 90 to 100 (92%), and received whole-pelvic RT+HT (67%). Of these patients, 13 % and 16% experienced late grade ≥2 bowel and bladder toxicities, respectively, and 2% and 3% experienced late grade ≥3 bowel and bladder toxicities, respectively. Late grade ≥2 clustered bowel and bladder toxicities were seen in approximately 1% of patients and late grade ≥3 clustered toxicities were seen in 2 patients (<1%). The multivariate analysis showed that patients who received prostate-only RT+HT had a lower risk of experiencing grade ≥2 bowel toxicities than those who received whole-pelvic RT+long-term (LT) HT (hazard ratio: 0.36; 95% confidence interval, 0.18-0.73; P = .0046 and hazard ratio: 0.43; 95% confidence interval, 0.23-0.80; P = .008, respectively). Patients who received whole-pelvic RT had similar chances of having grade ≥2 bowel or bladder toxicities no matter whether they received LT or short-term HT. CONCLUSIONS: Patients with high-risk prostate cancer who receive whole-pelvic RT+LT HT are more likely to have a grade ≥2 bowel toxicity than those who receive prostate-only RT. LT bowel and bladder toxicities were infrequent. Future studies will need to confirm these findings utilizing current radiation technology and patient-reported outcomes.

Preclinical biologic assessment of proton beam relative biologic effectiveness at Proton Therapy Center Houston.

The clinical use of protons for the treatment of cancer is one of the most technologically advanced forms of therapy. The newly commissioned M.D. Anderson Cancer Center, Proton Therapy Center Houston is one of the newest facilities offering a complete range of advanced proton therapies designed specifically to minimize treatment-related normal tissue toxicity. As an integral part of the clinical commissioning of this proton beam, we performed an in vivo assessment of the relative biologic effectiveness of the 250-MeV protons relative to standard cobalt(60) using the jejunal crypt microcolony assay in mice. Our data are consistent with a generic relative biologic effectiveness of 1.1, and this relative biologic effectiveness is in agreement with that used to describe most other clinical proton therapy beams worldwide.