Magnetic Resonance Image guided Stereotactic body radiotherapy (MRgRT) is an emerging technology that is increasingly used in treatment of visceral cancers, such as pancreatic adenocarcinoma (PDAC). ...Given the variable response rates and short progression times of PDAC, there is an unmet clinical need for a method to assess early RT response that may allow better prescription personalization. We hypothesize that quantitative image feature analysis (radiomics) of the longitudinal MR scans acquired before and during MRgRT may be used to extract information related to early treatment response.
Histogram and texture radiomic features (n = 73) were extracted from the Gross Tumor Volume (GTV) in 0.35T MRgRT scans of 26 locally advanced and borderline resectable PDAC patients treated with 50 Gy RT in 5 fractions. Feature ratios between first (F1) and last (F5) fraction scan were correlated with progression free survival (PFS). Feature stability was assessed through region of interest (ROI) perturbation.
Linear normalization of image intensity to median kidney value showed improved reproducibility of feature quantification. Histogram skewness change during treatment showed significant association with PFS (p = 0.005, HR = 2.75), offering a potential predictive biomarker of RT response. Stability analyses revealed a wide distribution of feature sensitivities to ROI delineation and was able to identify features that were robust to variability in contouring.
This study presents a proof-of-concept for the use of quantitative image analysis in MRgRT for treatment response prediction and providing an analysis pipeline that can be utilized in future MRgRT radiomic studies.
Summary
Emerging data suggests a benefit for using intensity modulated radiation therapy (IMRT) for the management of esophageal cancer. We retrospectively reviewed patients treated at our ...institution who received definitive or preoperative chemoradiation with either IMRT or 3D conformal radiation therapy (3DCRT) between October 2000 and January 2012. Kaplan Meier analysis and the Cox proportional hazard model were used to evaluate survival outcomes. We evaluated a total of 232 patients (138 IMRT, 94 3DCRT) who received a median dose of 50.4 Gy (range, 44–64.8) to gross disease. Median follow up for all patients, IMRT patients alone, and 3DCRT patients alone was 18.5 (range, 2.5–124.2), 16.5 (range, 3–59), and 25.9 months (range, 2.5–124.2), respectively. We observed no significant difference based on radiation technique (3DCRT vs. IMRT) with respect to median overall survival (OS) (median 29 vs. 32 months; P = 0.74) or median relapse free survival (median 20 vs. 25 months; P = 0.66). On multivariable analysis (MVA), surgical resection resulted in improved OS (HR 0.444; P < 0.0001). Superior OS was also associated on MVA with stage I/II disease (HR 0.523; P = 0.010) and tumor length ≤5 cm (HR 0.567; P = 0.006). IMRT was also associated on univariate analysis with a significant decrease in acute weight loss (mean 6% + 4.3% vs 9% + 7.4%, P = 0.012) and on MVA with a decrease in objective grade ≥3 toxicity, defined as any hospitalization, feeding tube, or >20% weight loss (OR 0.51; P = 0.050). Our data suggest that while IMRT‐based chemoradiation for esophageal cancer does not impact survival there was significantly less toxicity. In the IMRT group there was significant decrease in weight loss and grade ≥3 toxicity compared to 3DCRT.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
SUMMARY
We compared pathologic complete response (pCR) rate, toxicity, and postoperative complications between patients treated preoperatively with 50.4 Gy versus dose escalation with dose-painting ...intensity-modulated radiation therapy (dp-IMRT) to 56 Gy in locally advanced esophageal cancer. We evaluated esophageal cancer patients treated between 2006 and 2014 with preoperative IMRT chemoradiation to a dose of 50.4 Gy versus 56 Gy. The endpoints were pCR and toxicity. We identified 113 patients (50.4 Gy: n = 40; 56 Gy: n = 73). There were no significant differences in tumor or patient characteristics. Patients treated with 56 Gy demonstrated a higher pCR rate (56.2% vs. 30.0%) and lower pathologic nonresponse rate (4.1% vs. 20.0%) compared to patients treated to 50.4 Gy (P = 0.008). This remained significant on multivariate analysis (OR 3.375 95%CI 1.3-8.8, P = 0.013). Patients treated to 56 Gy also had an improved 3-year locoregional control rate compared to those treated to 50.4 Gy (93.8% vs. 78.5%; P = 0.022). The estimated 3-year freedom from failure was also superior in the 56 Gy arm (73.7% vs. 52.2%; P = 0.051), approaching significance. There were no differences in treatment related grade ≥3 toxicities, hospital admissions, feeding tube, esophageal stent placement, or dilation. There was, however, a statistically significant increase in postoperative atrial fibrillation in patients treated with 56 Gy (30.1% vs. 12.5%; P = 0.036). There was no difference in postoperative 30 or 60 day mortality. Dose escalation to 56 Gy with dp-IMRT is safe and results in significantly higher complete pathologic response rates in esophageal cancer without an increase in treatment-related toxicity. Prospective trials using dp-IMRT are needed to address the role of dose escalation on pCR rate and survival in esophageal cancer.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Bone metastases occur frequently in patients with advanced cancer and are a serious complication of cancer. The decision to treat is often individualized, based on each patient's clinical ...presentation, life expectancy, and quality of life.
We reviewed the current literature pertaining to management of metastatic disease to bone, and the medical, radiotherapeutic, and surgical treatment options for management of bone metastasis are discussed.
Current management of skeletal metastasis includes analgesia, systemic therapy, radiation therapy, and surgery. We propose treatment algorithms for management of vertebral and nonvertebral bone metastases and suggest individualized interventions based on clinical presentation.
Management of bone metastases is complex and requires a multidisciplinary approach. The goal of treatment is often palliative, and intervention and treatment regimens should be individualized based on the specific clinical presentation of each patient.
Evidence from the management of oligometastases with stereotactic body radiation therapy (SBRT) reveals differences in outcomes based on primary histology. We have previously identified a multigene ...expression index for tumor radiosensitivity (RSI) with validation in multiple independent cohorts. In this study, we assessed RSI in liver metastases and assessed our clinical outcomes after SBRT based on primary histology.
Patients were identified from our prospective, observational protocol. The previously tested RSI 10 gene assay was run on samples and calculated using the published algorithm. An independent cohort of 33 patients with 38 liver metastases treated with SBRT was used for clinical correlation.
A total of 372 unique metastatic liver lesions were identified for inclusion from our prospective, institutional metadata pool. The most common primary histologies for liver metastases were colorectal adenocarcinoma (n=314, 84.4%), breast adenocarcinoma (n=12, 3.2%), and pancreas neuroendocrine (n=11, 3%). There were significant differences in RSI of liver metastases based on histology. The median RSIs for liver metastases in descending order of radioresistance were gastrointestinal stromal tumor (0.57), melanoma (0.53), colorectal neuroendocrine (0.46), pancreas neuroendocrine (0.44), colorectal adenocarcinoma (0.43), breast adenocarcinoma (0.35), lung adenocarcinoma (0.31), pancreas adenocarcinoma (0.27), anal squamous cell cancer (0.22), and small intestine neuroendocrine (0.21) (P<.0001). The 12-month and 24-month Kaplan-Meier rates of local control (LC) for colorectal lesions from the independent clinical cohort were 79% and 59%, compared with 100% for noncolorectal lesions (P=.019), respectively.
In this analysis, we found significant differences based on primary histology. This study suggests that primary histology may be an important factor to consider in SBRT radiation dose selection.
Stereotactic body radiation therapy (SBRT) provides high rates of local control (LC) and margin-negative (R0) resections for locally advanced pancreatic cancer (LAPC) and borderline resectable ...pancreatic cancer (BRPC), respectively, with minimal toxicity.
A single-institution retrospective review was performed for patients with nonmetastatic pancreatic cancer treated with induction chemotherapy followed by SBRT. SBRT was delivered over 5 consecutive fractions using a dose painting technique including 7-10 Gy/fraction to the region of vessel abutment or encasement and 5-6 Gy/fraction to the remainder of the tumor. Restaging scans were performed at 4 weeks, and resectable patients were considered for resection. The primary endpoints were overall survival (OS) and progression-free survival (PFS).
Seventy-three patients were evaluated, with a median follow-up time of 10.5 months. Median doses of 35 Gy and 25 Gy were delivered to the region of vessel involvement and the remainder of the tumor, respectively. Thirty-two BRPC patients (56.1%) underwent surgery, with 31 undergoing an R0 resection (96.9%). The median OS, 1-year OS, median PFS, and 1-year PFS for BRPC versus LAPC patients was 16.4 months versus 15 months, 72.2% versus 68.1%, 9.7 versus 9.8 months, and 42.8% versus 41%, respectively (all P>.10). BRPC patients who underwent R0 resection had improved median OS (19.3 vs 12.3 months; P=.03), 1-year OS (84.2% vs 58.3%; P=.03), and 1-year PFS (56.5% vs 25.0%; P<.0001), respectively, compared with all nonsurgical patients. The 1-year LC in nonsurgical patients was 81%. We did not observe acute grade ≥3 toxicity, and late grade ≥3 toxicity was minimal (5.3%).
SBRT safely facilitates margin-negative resection in patients with BRPC pancreatic cancer while maintaining a high rate of LC in unresectable patients. These data support the expanded implementation of SBRT for pancreatic cancer.
Radiation therapy is a common and effective treatment modality in the management of skeletal metastases. Recent advances in technology permitting delivery of an ablative radiation dose with an ...image-guided stereotactic approach improve the therapeutic threshold.
The authors reviewed the literature on conventional external-beam radiation therapy and summarized the emerging data about image-guided stereotactic body radiation therapy (SBRT) for vertebral oligometastasis.
Pain control can be achieved effectively with conventional external-beam radiation therapy and may be further improved with image-guided spinal SBRT. Image-guided SBRT allows delivery of an ablative radiation dose with minimal toxicity, may potentially improve local tumor control, and may enhance clinical outcomes for histologies that are considered radioresistant. However, further understanding of long-term normal tissue toxicity is lacking.
Radiotherapy options are expanding for patients with skeletal metastases. Image-guided spinal SBRT can deliver a safe ablative radiation dose to improve pain control and potentially local tumor control. Randomized clinical trials are ongoing to assess clinical benefits and outcome with spinal SBRT.
Abstract only
327
Background: Fiducial markers implanted into tumors that move with respiration facilitate planning for SBRT. To date, there is little evidence regarding the safety and utility of EUS ...implanted markers for “borderline resectable” pancreatic cancer.
Methods: This is a retrospective review of 13 patients (7 men and 6 women) with “borderline resectable” pancreatic cancer as per NCCN guidelines. EUS-guided fiducial placement for stereotactic body radiation therapy was performed between January 2009 and September 2010. Gold cylindrical fiducials (0.35mmx 10mm or 0.75 mm X 10 mm; VISICOIL) were loaded into a 22g or 19 g EUS needle. With the needle in the target, the fiducial was deployed by retracting the needle and advancing the stylet. EUS confirmed fiducial position after deployment. A mean of 3 fiducials were placed (range 1-6) per patient. Fiducial position was analyzed at 4D CT simulation and daily cone beam imaging prior to SBRT.
Results: Fiducial placement was successful in all. Technical difficulty was encountered in 2 patients secondary to retained food in stomach and uncinate tumors. Smaller (10x0.35mm) fiducials were successfully placed in these 2 patients. 3 patients had abdominal pain lasting < 12 hours after fiducial placement but none had any acute complications. In 2 patients, change in fiducial position was noted on follow-up cone beam CT. This apparent change in position was related to biliary drainage, gastric distension and a pre-existing pseudocyst. Though this is not indicative of fiducial migration, it impacts radiation planning and delivery. No complications were noted at the end of a mean follow-up period of 6 months.
Conclusions: EUS fiducial placement to assist with stereotactic body radiation for “borderline resectable” pancreatic cancer is safe, feasible, and technically successful in most cases. True migration did not occur but other factors may cause an apparent change in fiducial position. Further studies are planned to optimize the best configuration of fiducial placement by virtue of tumor location for SBRT planning and treatment.
No significant financial relationships to disclose.
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