Adjuvant Chemoradiation in Pancreatic Cancer: A Pooled Analysis in Elderly (≥75 years) Patients

AIM

To determine the impact of postoperative chemoradiation (POCR) on overall survival (OS) after resection of pancreatic adenocarcinoma (PAC) in elderly (≥75 years) patients.

MATERIALS AND METHODS

A multi-center retrospective review of 1248 patients who underwent complete resection with macroscopically negative margins (R0-1) for invasive PAC was performed. Exclusion criteria included age <75 years, metastatic or unresectable disease at surgery, macroscopic residual disease (R2), treatment with intraoperative radiotherapy (IORT) and postoperative death.

RESULTS

A total of 98 patients were included in the analysis (males=39.8%, females=60.2%; R1 resections=33.7%; pN1=61.2%); 63 patients received POCR and 26 patients received adjuvant chemotherapy alone. The median follow-up was 25.6 months. The mean age for the entire cohort of patients was 78.1±2.9 (SD) years. No differences were observed between patients receiving or not receiving POCR in terms of age (p=0.081), tumor diameter (p=0.412), rate of R1 resection (p=0.331) and incidence of lymph node-positive disease (p=0.078). The only factor predicting an improved OS was POCR. The median OS was 69.0 months in patients treated by POCR and 23.0 months in patients treated without POCR (p=0.008). Even by Cox multivariate analysis, the only significant predictor of OS was POCR (hazard ratio=0.449; 95% confidence interval=0.212-0.950; p=0.036).

CONCLUSION

The study represents the first comparative approach on POCR in elderly patients after resection of PAC. OS was higher in patients who received POCR. Further analyses are warranted to evaluate the toxicity rate/grade and the impact of POCR on patient quality of life.

Adjuvant chemoradiation for pancreatic cancer: what does the evidence tell us?

The role of adjuvant chemoradiation (CRT) for pancreas cancer remains unclear. A handful of randomized trials conducted decades of ago ignited a debate that continues today about whether CRT improves survival after surgery. The many flaws in these trials are well described in the literature, which include the use of antiquated radiation delivery techniques and suboptimal doses. Recent prospective randomized data is lacking, and we eagerly await the results the ongoing Radiation Therapy Oncology Group (RTOG) 0848 trial that is evaluating the utility of high quality adjuvant CRT in resected pancreas cancer patients. Until the results of RTOG 0848 are available we should look to other studies from the modern era to guide adjuvant treatment recommendations. Here we review the current state of the art for adjuvant pancreas CRT with respect to patient selection, radiation techniques, radiation dose, and integration with novel systemic agents.

Dosimetric and geometric evaluation of a novel stereotactic radiotherapy device for breast cancer: the GammaPod™

PURPOSE

A dedicated stereotactic gamma irradiation device, the GammaPod™ from Xcision Medical Systems, was developed specifically to treat small breast cancers. This study presents the first evaluation of dosimetric and geometric characteristics from the initial prototype installed at University of Maryland Radiation Oncology Department.

METHODS

The GammaPod™ stereotactic radiotherapy device is an assembly of a hemi-spherical source carrier containing 36 (60)Co sources, a tungsten collimator, a dynamically controlled patient support table, and the breast immobilization system which also functions as a stereotactic frame. The source carrier contains the sources in six columns spaced longitudinally at 60° intervals and it rotates together with the variable-size collimator to form 36 noncoplanar, concentric arcs focused at the isocenter. The patient support table enables motion in three dimensions to position the patient tumor at the focal point of the irradiation. The table moves continuously in three cardinal dimensions during treatment to provide dynamic shaping of the dose distribution. The breast is immobilized using a breast cup applying a small negative pressure, where the immobilization cup is embedded with fiducials also functioning as the stereotactic frame for the breast. Geometric and dosimetric evaluations of the system as well as a protocol for absorbed dose calibration are provided. Dosimetric verifications of dynamically delivered patient plans are performed for seven patients using radiochromic films in hypothetical preop, postop, and target-in-target treatment scenarios.

RESULTS

Loaded with 36 (60)Co sources with cumulative activity of 4320 Ci, the prototype GammaPod™ unit delivers 5.31 Gy/min at the isocenter using the largest 2.5 cm diameter collimator. Due to the noncoplanar beam arrangement and dynamic dose shaping features, the GammaPod™ device is found to deliver uniform doses to targets with good conformity. The spatial accuracy of the device to locate the radiation isocenter is determined to be less than 1 mm. Single shot profiles with 2.5 cm collimator are measured with radiochromic film and found to be in good agreement with respect to the Monte Carlo based calculations (congruence of FWHM less than 1 mm). Dosimetric verifications corresponding to all hypothetical treatment plans corresponding to three target scenarios for each of the seven patients demonstrated good agreement with gamma index pass rates of better than 97% (99.0% ± 0.7%).

CONCLUSIONS

Dosimetric evaluation of the first GammaPod™ stereotactic breast radiotherapy unit was performed and the dosimetric and spatial accuracy of this novel technology is found to be feasible with respect to clinical radiotherapy standards. The observed level of agreement between the treatment planning system calculations and dosimetric measurements has confirmed that the system can deliver highly complex treatment plans with remarkable geometric and dosimetric accuracy.

Dosimetric comparison between intra-cavitary breast brachytherapy techniques for accelerated partial breast irradiation and a novel stereotactic radiotherapy device for breast cancer: GammaPod™

The GammaPod™ device, manufactured by Xcision Medical Systems, is a novel stereotactic breast irradiation device. It consists of a hemispherical source carrier containing 36 Cobalt-60 sources, a tungsten collimator with two built-in collimation sizes, a dynamically controlled patient support table and a breast immobilization cup also functioning as the stereotactic frame for the patient. The dosimetric output of the GammaPod™ was modelled using a Monte Carlo based treatment planning system. For the comparison, three-dimensional (3D) models of commonly used intra-cavitary breast brachytherapy techniques utilizing single lumen and multi-lumen balloon as well as peripheral catheter multi-lumen implant devices were created and corresponding 3D dose calculations were performed using the American Association of Physicists in Medicine Task Group-43 formalism. Dose distributions for clinically relevant target volumes were optimized using dosimetric goals set forth in the National Surgical Adjuvant Breast and Bowel Project Protocol B-39. For clinical scenarios assuming similar target sizes and proximity to critical organs, dose coverage, dose fall-off profiles beyond the target and skin doses at given distances beyond the target were calculated for GammaPod™ and compared with the doses achievable by the brachytherapy techniques. The dosimetric goals within the protocol guidelines were fulfilled for all target sizes and irradiation techniques. For central targets, at small distances from the target edge (up to approximately 1 cm) the brachytherapy techniques generally have a steeper dose fall-off gradient compared to GammaPod™ and at longer distances (more than about 1 cm) the relation is generally observed to be opposite. For targets close to the skin, the relative skin doses were considerably lower for GammaPod™ than for any of the brachytherapy techniques. In conclusion, GammaPod™ allows adequate and more uniform dose coverage to centrally and peripherally located targets with an acceptable dose fall-off and lower relative skin dose than the brachytherapy techniques considered in this study.

Abstract 3553: Elevated expression of mismatch repair enzyme MLH1 is associated with prolonged overall survival in resected pancreatic cancer treated with adjuvant chemoradiation, a biomarker analysis of RTOG 9704

Introduction

RTOG 9704 was a randomized phase III trial comparing two different adjuvant protocols in patients with resected pancreatic adenocarcinoma. All patients received concurrent 5FU-radiation (RT) therapy, in addition the control arm received 5FU prior to- and following RT, whereas the experimental arm received gemcitabine. MLH1 loss is associated with treatment resistance and genetic instability in the laboratory. It is hypothesized that tumors with higher levels of MLH1 expression would have a better prognosis.

Methods

A Tissue microarray prepared from paraffin blocks removed at time of operation was examined for MLH1 expression using fluorescence immunohistochemistry and analyzed using automated quantitative analysis software (AQUA) from HistoRx. For the purposes of part of the analysis MLH1 levels were dichotomized above and below the median expression value. Clinical endpoints were disease-free and overall-survival. Statistical techniques included the chi-square, Fisher's exact test and the Kaplan-Meier method. A p-value of &lt;0.01 was considered significant to allow for multiple comparisons.

Results

Of the 451 eligible patients enrolled on the trial, immunohistochemistry staining was successfully performed for 117 patients for MLH1 (60 and 57 from the 2 arms). Characteristics from those with tissue were similar to the trial population as a whole. At the time of analysis 84% of the participants had died, with a median survival of 17 months (min-max: 14 to 21 months). Elevated MLH1 levels in tumor nuclei were correlated with longer disease-free and overall survival in both arms of the trial, both individually and combined. Two year overall survival was 16% in those with low MLH1 levels and 53% for those with high levels, p&lt;0.0001 (both arms combined). This association remained true on multivariate analysis allowing for nodal status (HR=0.41, p&lt;0.0001).

Conclusions

The expression of MLH1 correlates with long-term survival in resected pancreatic cancer treated with post-operative chemoradiation. It is suggested that, following validation, MLH1 be used as stratification markers in future clinical trials of DNA damaging agents in pancreatic cancer.

This project was supported by RTOG grants U10 CA21661, CCOP grant U10 CA37422, and RTOG Biospecimen Resource grant U24 CA114734 from the National Cancer Institute (NCI).

Citation Format: Yaacov Richard Lawrence, Jennifer Moughan, Anthony Magliocco, Alexander Klimowicz, William F. Regine, Rex B. Mowat, Thomas A. DiPetrillo, William Small, Kathryn Winter, Chandan Guha, Christopher Crane, Adam P. Dicker. Elevated expression of mismatch repair enzyme MLH1 is associated with prolonged overall survival in resected pancreatic cancer treated with adjuvant chemoradiation, a biomarker analysis of RTOG 9704. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3553. doi:10.1158/1538-7445.AM2013-3553

Increasing national mastectomy rates for the treatment of early stage breast cancer

BACKGROUND

To study national trends in the mastectomy rate for treatment of early stage breast cancer.

METHODS

We analyzed data from the Surveillance, Epidemiology, and End Results database, including 256,081 women diagnosed with T1-2 N0-3 M0 breast cancer from 2000 to 2008. We evaluated therapeutic mastectomy rates by the year of diagnosis and performed a multivariable logistic regression analyses to determine predictors of mastectomy as the treatment choice.

RESULTS

The proportion of women treated with mastectomy decreased from 40.1 to 35.6 % between 2000 and 2005. Subsequently, the mastectomy rate increased to 38.4 % in 2008 (p < 0.0001). Simple logistic regression models demonstrated that mastectomy rates between 2005 and 2008 were moderated by age (p < 0.0001), marital status (p = 0.0230), and geographic location (p < 0.0001). Multivariate logistic regression analysis found that age, race, marital status, geographic location, involvement of multiple regions of the breast, lobular histology, increasing T stage, lymph node positivity, increasing grade, and negative hormone receptor status were independent predictors of mastectomy. Additionally, multivariate analysis confirmed that women diagnosed in 2008 were more likely to undergo mastectomy than women diagnosed in 2005 (odds ratio 1.17, 95 % confidence interval 1.13 to 1.21, p < 0.0001).

CONCLUSIONS

There is evidence of a reversal in the previously declining national mastectomy rates, with the mastectomy rate reaching a nadir in 2005 and subsequently rising. Further follow-up to confirm this trend and investigation to determine the underlying cause of this trend and its effect on outcomes may be warranted.

Coping and its effects on cancer caregiving

PURPOSE

Various studies have documented the emotional distress family members of persons with cancer experience, and descriptive research has identified those psychosocial factors that protect cancer caregivers from a range of negative outcomes. The objective of this study was to determine how different coping strategies were associated with multiple domains of stress and negative health outcomes among cancer family caregivers.

METHODS

A cross-sectional, correlational study design was used. One hundred forty-eight family caregivers of persons with cancer from the University of Minnesota Masonic Cancer Center and the University of Maryland Greenebaum Cancer Center were included.

RESULTS

Multiple regression models found that negative expectation coping strategies (worrying, expecting the worst, and getting nervous) and cancer caregivers' perceptions of not coping well were most significantly associated with emotional distress and negative psychological outcomes.

CONCLUSION

Coping strategies, and in particular negative coping styles, have a consistent and exacerbating influence on various stressors and negative psychological outcomes for cancer caregivers. Given their pervasive effects across multiple stress process domains, the alleviation or redirection of negative expectation coping strategies may enhance the delivery of clinical interventions to result in stronger, long-lasting benefits.

Radiation Therapy Oncology Group consensus panel guidelines for the delineation of the clinical target volume in the postoperative treatment of pancreatic head cancer

PURPOSE

To develop contouring guidelines to be used in the Radiation Therapy Oncology Group protocol 0848, a Phase III randomized trial evaluating the benefit of adjuvant chemoradiation in patients with resected head of pancreas cancer.

METHODS AND MATERIALS

A consensus committee of six radiation oncologists with expertise in gastrointestinal radiotherapy developed stepwise contouring guidelines and an atlas for the delineation of the clinical target volume (CTV) in the postoperative treatment of pancreas cancer, based on identifiable regions of interest and margin expansions. Areas at risk for subclinical disease to be included in the CTV were defined, including nodal regions, anastomoses, and the preoperative primary tumor location. Regions of interest that could be reproducibly contoured on postoperative imaging after a pancreaticoduodenectomy were identified. Standardized expansion margins to encompass areas at risk were developed after multiple iterations to determine the optimal margin expansions.

RESULTS

New contouring recommendations based on CT anatomy were established. Written guidelines for the delineation of the postoperative CTV and normal tissues, as well as a Web-based atlas, were developed.

CONCLUSIONS

The postoperative abdomen has been a difficult area for effective radiotherapy. These new guidelines will help physicians create fields that better encompass areas at risk and minimize dose to normal tissues.

Analysis of local control in patients receiving IMRT for resected pancreatic cancers

PURPOSE

Intensity-modulated radiotherapy (IMRT) is increasingly incorporated into therapy for pancreatic cancer. A concern regarding this technique is the potential for geographic miss and decreased local control. We analyzed patterns of first failure among patients treated with IMRT for resected pancreatic cancer.

METHODS AND MATERIALS

Seventy-one patients who underwent resection and adjuvant chemoradiation for pancreas cancer are included in this report. IMRT was used for all to a median dose of 50.4 Gy. Concurrent chemotherapy was 5-FU-based in 72% of patients and gemcitabine-based in 28%.

RESULTS

At median follow-up of 24 months, 49/71 patients (69%) had failed. The predominant failure pattern was distant metastases in 35/71 patients (49%). The most common site of metastases was the liver. Fourteen patients (19%) developed locoregional failure in the tumor bed alone in 5 patients, regional nodes in 4 patients, and concurrently with metastases in 5 patients. Median overall survival (OS) was 25 months. On univariate analysis, nodal status, margin status, postoperative CA 19-9 level, and weight loss during treatment were predictive for OS. On multivariate analysis, higher postoperative CA19-9 levels predicted for worse OS on a continuous basis (p < 0.01). A trend to worse OS was seen among patients with more weight loss during therapy (p = 0.06). Patients with positive nodes and positive margins also had significantly worse OS (HR for death 2.8, 95% CI 1.1-7.5; HR for death 2.6, 95% CI 1.1-6.2, respectively). Grade 3-4 nausea and vomiting was seen in 8% of patients. Late complication of small bowel obstruction occurred in 4 (6%) patients.

CONCLUSIONS

This is the first comprehensive report of patterns of failure among patients treated with adjuvant IMRT for pancreas cancer. IMRT was not associated with an increase in local recurrences in our cohort. These data support the use of IMRT in the recently activated EORTC/US Intergroup/RTOG 0848 adjuvant pancreas trial.

Protons offer reduced normal-tissue exposure for patients receiving postoperative radiotherapy for resected pancreatic head cancer

PURPOSE

To determine the potential role for adjuvant proton-based radiotherapy (PT) for resected pancreatic head cancer.

METHODS AND MATERIALS

Between June 2008 and November 2008, 8 consecutive patients with resected pancreatic head cancers underwent optimized intensity-modulated radiotherapy (IMRT) treatment planning. IMRT plans used between 10 and 18 fields and delivered 45 Gy to the initial planning target volume (PTV) and a 5.4 Gy boost to a reduced PTV. PTVs were defined according to the Radiation Therapy Oncology Group 9704 radiotherapy guidelines. Ninety-five percent of PTVs received 100% of the target dose and 100% of the PTVs received 95% of the target dose. Normal tissue constraints were as follows: right kidney V18 Gy to <70%; left kidney V18 Gy to <30%; small bowel/stomach V20 Gy to <50%, V45 Gy to <15%, V50 Gy to <10%, and V54 Gy to <5%; liver V30 Gy to <60%; and spinal cord maximum to 46 Gy. Optimized two- to three-field three-dimensional conformal proton plans were retrospectively generated on the same patients. The team generating the proton plans was blinded to the dose distributions achieved by the IMRT plans. The IMRT and proton plans were then compared. A Wilcoxon paired t-test was performed to compare various dosimetric points between the two plans for each patient.

RESULTS

All proton plans met all normal tissue constraints and were isoeffective with the corresponding IMRT plans in terms of PTV coverage. The proton plans offered significantly reduced normal-tissue exposure over the IMRT plans with respect to the following: median small bowel V20 Gy, 15.4% with protons versus 47.0% with IMRT (p = 0.0156); median gastric V20 Gy, 2.3% with protons versus 20.0% with IMRT (p = 0.0313); and median right kidney V18 Gy, 27.3% with protons versus 50.5% with IMRT (p = 0.0156).

CONCLUSIONS

By reducing small bowel and stomach exposure, protons have the potential to reduce the acute and late toxicities of postoperative chemoradiation in this setting.

The influence of total nodes examined, number of positive nodes, and lymph node ratio on survival after surgical resection and adjuvant chemoradiation for pancreatic cancer: a secondary analysis of RTOG 9704

PURPOSE

Lymph node status is an important predictor of survival in pancreatic cancer. We performed a secondary analysis of Radiation Therapy Oncology Group (RTOG) 9704, an adjuvant chemotherapy and chemoradiation trial, to determine the influence of lymph node factors--number of positive nodes (NPN), total nodes examined (TNE), and lymph node ratio (LNR ratio of NPN to TNE)--on OS and disease-free survival (DFS).

PATIENT AND METHODS

Eligible patients from RTOG 9704 form the basis of this secondary analysis of lymph node parameters. Actuarial estimates for OS and DFS were calculated using Kaplan-Meier methods. Cox proportional hazards models were performed to evaluate associations of NPN, TNE, and LNR with OS and DFS. Multivariate Cox proportional hazards models were also performed.

RESULTS

There were 538 patients enrolled in the RTOG 9704 trial. Of these, 445 patients were eligible with lymph nodes removed. Overall median NPN was 1 (min-max, 0-18). Increased NPN was associated with worse OS (HR=1.06, p=0.001) and DFS (HR=1.05, p=0.01). In multivariate analyses, both NPN and TNE were associated with OS and DFS. TNE>12, and >15 were associated with increased OS for all patients, but not for node-negative patients (n=142). Increased LNR was associated with worse OS (HR=1.01, p<0.0001) and DFS (HR=1.006, p=0.002).

CONCLUSION

In patients who undergo surgical resection followed by adjuvant chemoradiation, TNE, NPN, and LNR are associated with OS and DFS. This secondary analysis of a prospective, cooperative group trial supports the influence of these lymph node parameters on outcomes after surgery and adjuvant therapy using contemporary techniques.

Fluorouracil-based chemoradiation with either gemcitabine or fluorouracil chemotherapy after resection of pancreatic adenocarcinoma: 5-year analysis of the U.S. Intergroup/RTOG 9704 phase III trial

BACKGROUND

The impact of the addition of gemcitabine to 5-fluorouracil (5-FU) chemoradiation (CRT) on 5-year overall survival (OS) in resected pancreatic adenocarcinoma are presented with updated results of a phase III trial.

METHODS

After resection of pancreatic adenocarcinoma, patients were randomized to pre- and post-CRT 5-FU versus pre- and post-CRT gemcitabine. 5-FU was provided continuously at 250 mg/m(2)/day, and gemcitabine was provided at 1000 mg/m(2) weekly. Both were provided over 3 weeks before and 12 weeks after CRT. CRT was provided at 50.4 Gy with continuously provided 5-FU. The primary end point was survival for all patients and for patients with tumor of the pancreatic head.

RESULTS

Four hundred fifty-one patients were eligible. Univariate analysis showed no difference in OS. Pancreatic head tumor patients (n = 388) had a median survival and 5-year OS of 20.5 months and 22% with gemcitabine versus 17.1 months and 18% with 5-FU. On multivariate analysis, patients on the gemcitabine arm with pancreatic head tumors experienced a trend toward improved OS (P = 0.08). First site of relapse local recurrence in 28% of patients versus distant relapse in 73%.

CONCLUSIONS

The sequencing of 5-FU CRT with gemcitabine as done in this trial is not associated with a statistically significant improvement in OS. Despite local recurrence being approximately half of that reported in previous adjuvant trials, distant disease relapse still occurs in ≥ 70% of patients. These findings serve as the basis for the recently activated EORTC/U.S. Intergroup RTOG 0848 phase III adjuvant trial evaluating the impact of CRT after completion of a full course of gemcitabine.

Failure to adhere to protocol specified radiation therapy guidelines was associated with decreased survival in RTOG 9704--a phase III trial of adjuvant chemotherapy and chemoradiotherapy for patients with resected adenocarcinoma of the pancreas

PURPOSE

In Radiation Therapy Oncology Group 9704, as previously published, patients with resected pancreatic adenocarcinoma received continuous infusion 5-FU and concurrent radiotherapy (5FU-RT). 5FU-RT treatment was preceded and followed by randomly assigned chemotherapy, either 5-FU or gemcitabine. This analysis explored whether failure to adhere to specified RT guidelines influenced survival and/or toxicity.

METHODS AND MATERIALS

RT requirements were protocol specified. Adherence was scored as per protocol (PP) or less than per protocol (<PP). Scoring occurred after therapy but before trial analysis and without knowledge of individual patient treatment outcomes. Scoring was done for all tumor locations and for the subset of pancreatic head location.

RESULTS

RT was scored for 416 patients: 216 PP and 200 <PP. For all pancreatic sites (head, body/tail) median survival (MS) for PP vs. <PP was 1.74 vs. 1.46 years (log-rank p = 0.0077). In multivariate analysis, PP vs. <PP score correlated more strongly with MS than assigned treatment arm (p = 0.014, p = NS, respectively); for patients with pancreatic head tumors, both PP score and gemcitabine treatment correlated with improved MS (p = 0.016, p = 0.043, respectively). For all tumor locations, PP score was associated with decreased risk of failure (p = 0.016) and, for gemcitabine patients, a trend toward reduced Grade 4/5 nonhematologic toxicity (p = 0.065).

CONCLUSIONS

This is the first Phase III, multicenter, adjuvant protocol for pancreatic adenocarcinoma to evaluate the impact of adherence to specified RT protocol guidelines on protocol outcomes. Failure to adhere to specified RT guidelines was associated with reduced survival and, for patients receiving gemcitabine, trend toward increased nonhematologic toxicity.

Spine radiosurgery for spinal cord compression: the radiation oncologist's perspective

Metastatic spinal cord compression (MSCC) is a common problem afflicting cancer patients. It affects 5-14% of all patients with cancer, and more than 20,000 cases are diagnosed annually in the United States (1-3). Once diagnosed, it is considered to be a medical emergency, and immediate intervention is required with high-dose corticosteroids and radiotherapy (RT), with or without decompressive surgery. Without therapy, MSCC is a source of significant morbidity and mortality, causing pain, paralysis, incontinence, and an overall decline in quality of life. Even with aggressive therapy, results can often be unsatisfactory. Although most patients will die of their underlying cancer within the first year of the diagnosis of MSCC, up to one-third will survive beyond one year (4-5). Therefore, optimal therapy is required to maintain quality of life.

Intensity-modulated radiation therapy significantly improves acute gastrointestinal toxicity in pancreatic and ampullary cancers

PURPOSE

Among patients with upper abdominal malignancies, intensity-modulated radiation therapy (IMRT) can improve dose distributions to critical dose-limiting structures near the target. Whether these improved dose distributions are associated with decreased toxicity when compared with conventional three-dimensional treatment remains a subject of investigation.

METHODS AND MATERIALS

46 patients with pancreatic/ampullary cancer were treated with concurrent chemoradiation (CRT) using inverse-planned IMRT. All patients received CRT based on 5-fluorouracil in a schema similar to Radiation Therapy Oncology Group (RTOG) 97-04. Rates of acute gastrointestinal (GI) toxicity for this series of IMRT-treated patients were compared with those from RTOG 97-04, where all patients were treated with three-dimensional conformal techniques. Chi-square analysis was used to determine if there was a statistically different incidence in acute GI toxicity between these two groups of patients.

RESULTS

The overall incidence of Grade 3-4 acute GI toxicity was low in patients receiving IMRT-based CRT. When compared with patients who had three-dimensional treatment planning (RTOG 97-04), IMRT significantly reduced the incidence of Grade 3-4 nausea and vomiting (0% vs. 11%, p = 0.024) and diarrhea (3% vs. 18%, p = 0.017). There was no significant difference in the incidence of Grade 3-4 weight loss between the two groups of patients.

CONCLUSIONS

IMRT is associated with a statistically significant decrease in acute upper and lower GI toxicity among patients treated with CRT for pancreatic/ampullary cancers. Future clinical trials plan to incorporate the use of IMRT, given that it remains a subject of active investigation.

ACR Appropriateness Criteria: local excision in early-stage rectal cancer

Low anterior resection or abdominoperineal resection is considered standard treatment for early rectal cancer. These procedures, however, carry a risk of morbidity and mortality that may not be warranted for early distal lesions, which may be treated with local excision. Emerging data has investigated the efficacy of local excision in patients with early stage rectal cancers. An expert panel designated by the American College of Radiology has reviewed supporting data, from a few prospective multi-institutional trials and a number of single-institution, retrospective reviews. The consensus recognizes the importance of accurate staging to identify patients who may be candidates for a local excision approach. Optimal candidates for local excision alone include small, low-lying T1 tumors, without adverse pathologic features. A number of procedures may be safely used including transanal, posterior trans-sphincteric, posterior proctotomy, transanal excision, or transanal microsurgery. It is important to note that none of these include lymph node evaluation, and depending on the risk of lymph node metastases, adjuvant radiation with or without chemotherapy may be warranted. Patients with positive margins or T3 lesions are at high risk of local recurrence and should be offered immediate APR or LAR. However, patients with high-risk T1 tumors, T2 tumors, or those who are not amenable to more radical surgery may benefit from adjuvant treatment. Data have also reported excellent local control rates for neoadjuvant radiation +/- chemotherapy followed by local excision in higher risk patients, but it is not yet clear if this approach reduces recurrence rates over surgery alone.

Factors impacting volumetric white matter changes following whole brain radiation therapy

Whole brain radiation therapy (WBRT) is one of the most effective modalities for treatment of brain metastases. With increasing cancer control there is growing concern regarding the long-term effects of treatment. These effects are seen as white matter change (WMC) on brain MRI. Severity of WMC is implicated in cognitive and functional decline in many patient groups. Our objective was to identify clinical factors associated with greater accumulation of WMC following WBRT. Through retrospective review of serial MRIs obtained from 30 patients surviving greater than 1 year after WBRT, treated at a single institution between 2002 and 2007, we calculated volumetric WMC over time using segmentation software. Changes related to tumor, secondary effects, surgery or radiosurgery were excluded. Factors that influenced the rate of WMC accumulation were identified through multivariate analysis. Following WBRT, patients accumulated WMC at an average rate of 0.07% of total brain volume per month. In multivariate analyses, greater rates of accumulation were independently associated with older age (β = 0.004, p < .0001), poor levels of glycemic control (β = 0.048, p < .0001) and hypertension diagnosis (β = 0.084, p < .0001). Long-term survivors of cancer allow assessment of late effects of treatment modalities. Radiation injury appears to be related to a steady rate of white matter damage over time, as indicated by progressive accumulation of WMC. Our results suggest that rate of WMC accumulation is enhanced by parameters such as hyperglycemia and hypertension. This has significant clinical impact by clearly identifying hyperglycemia, steroid-induced hyperglycemia, and other vascular risk factors as targets for intervention to decrease WMC in patients receiving WBRT.