Chest Magnetic Resonance Imaging Decreases Inter-observer Variability of Gross Target Volume for Lung Tumors.

Purpose: PET/CT is a standard medical imaging used in the delineation of gross tumor volume (GTV) in case of radiation therapy for lung tumors. However, PET/CT could present some limitations such as resolution and standardized uptake value threshold. Moreover, chest MRI has shown good potential in diagnosis for thoracic oncology. Therefore, we investigated the influence of chest MRI on inter-observer variability of GTV delineation. Methods and Materials: Five observers contoured the GTV on CT for 14 poorly defined lung tumors during three contouring phases based on true daily clinical routine and acquisition: CT phase, with only CT images; PET phase, with PET/CT; and MRI phase, with both PET/CT and MRI. Observers waited at least 1 week between each phases to decrease memory bias. Contours were compared using descriptive statistics of volume, coefficient of variation (COV), and Dice similarity coefficient (DSC). Results: MRI phase volumes (median 4.8 cm3) were significantly smaller than PET phase volumes (median 6.4 cm3, p = 0.015), but not different from CT phase volumes (median 5.7 cm3, p = 0.30). The mean COV was improved for the MRI phase (0.38) compared to the CT (0.58, p = 0.024) and PET (0.53, p = 0.060) phases. The mean DSC of the MRI phase (0.67) was superior to those of the CT and PET phases (0.56 and 0.60, respectively; p < 0.001 for both). Conclusions: The addition of chest MRI seems to decrease inter-observer variability of GTV delineation for poorly defined lung tumors compared to PET/CT alone and should be explored in further prospective studies.

Radiological imaging markers predicting clinical outcome in patients with metastatic colorectal carcinoma treated with regorafenib: post hoc analysis of the CORRECT phase III trial (RadioCORRECT study).

OBJECTIVE: To identify imaging markers predicting clinical outcomes to regorafenib in metastatic colorectal carcinoma (mCRC). METHODS: The RadioCORRECT study is a post hoc analysis of a cohort of patients with mCRC treated within the phase III placebo-controlled CORRECT trial of regorafenib. Baseline and week 8 contrast-enhanced CT were used to assess response by RECIST 1.1, changes in the sum of target lesion diameters (ΔSTL), lung metastases cavitation and liver metastases density. Primary and secondary objectives were to develop ex novo univariable and multivariable models to predict overall survival (OS) and progression-free survival (PFS), respectively. RESULTS: 202 patients were enrolled, 134 (66.3%) treated with regorafenib and 68 (33.7%) with placebo. In the univariate analysis, PFS predictors were lung metastases cavitation at baseline (HR 0.50, 95% CI 0.27 to 0.92, p=0.03) and at week 8 (HR 0.58, 95% CI 0.36 to 0.93, p=0.02). Baseline cavitation (HR 0.23, 95% CI 0.08 to 0.66, p=0.007), RECIST 1.1 (HR 0.23, 95% CI 0.14 to 0.4, p <0.0001) and ΔSTL (HR 1.16, 95% CI 1.06 to 1.27, p=0.002) predicted OS. We found an increase of 9% of diameter as the best threshold for discriminating OS (HR 2.64, 95% CI 1.61 to 4.34, p <0.001). In the multivariate analysis, baseline and week 8 cavitation remained significant PFS predictors. Baseline cavitation, RECIST 1.1 and ΔSTL remained predictors of OS in exploratory multivariable models. Assessment of liver metastases density did not predict clinical outcome. CONCLUSIONS: RECIST 1.1 and ΔSTL predict favourable outcome to regorafenib. In contrast to liver metastases density that failed to be a predictor, lung metastases cavitation represents a novel radiological marker of favourable outcome that deserves consideration.

Lobulated enhancement evaluation in the follow-up of liver metastases treated by stereotactic body radiation therapy.

OBJECTIVE: The Response Evaluation Criteria in Solid Tumors (RECIST) can have limitations when used to evaluate local treatments for cancer, especially for liver malignancies treated by stereotactic body radiation therapy (SBRT). The aim of this study was to validate the relationship between the occurrence of lobulated enhancement (LE) and local relapse and to evaluate the utility of this relationship for predicting local progression. PATIENTS AND METHODS: Imaging data of 59 lesions in 46 patients, including 281 computed tomographic (CT) scans, were retrospectively and blindly reviewed by 3 radiologists. One radiologist measured the lesion size, for each CT and overall, to classify responses using RECIST threshold criteria. The second studied LE occurrence. A third radiologist was later included and studied LE occurrence to evaluate the interobserver consistency for LE evaluation. RESULTS: The mean duration of follow-up was 13.6 months. LE was observed in 16 of 18 progressive lesions, occurring before size-based progression in 50% of cases, and the median delay of LE detection was 3.2 months. The sensitivity of LE to predict progression was 89%, and its specificity was 100%. The positive predictive value was 100%, the negative predictive value was 95.3%, and the overall accuracy was 97%. The probability of local progression-free survival at 12 months was significantly higher for lesions without LE compared with all lesions: 0.80 (CI 95%: 0.65-0.89) versus 0.69 (CI 95%: 0.54-0.80), respectively. The overall concordance rate between the 2 readers of LE was 97.9%. CONCLUSION: Response assessment of liver metastases treated by SBRT can be improved by including LE. This study demonstrates the diagnostic and predictive utility of LE for assessing local progression at a size still eligible for local salvage treatment.

Novel technique for hepatic fiducial marker placement for stereotactic body radiation therapy.

PURPOSE: To report experience with fiducial marker insertion and describe an advantageous, novel technique for fiducial placement in the liver for stereotactic body radiation therapy with respiratory tracking. METHODS AND MATERIALS: We implanted 1444 fiducials (single: 834; linked: 610) in 328 patients with 424 hepatic lesions. Two methods of implantation were compared: the standard method (631 single fiducials) performed on 153 patients from May 2007 to May 2010, and the cube method (813 fiducials: 610 linked/203 single) applied to 175 patients from April 2010 to March 2013. The standard method involved implanting a single marker at a time. The novel technique entailed implanting 2 pairs of linked markers when possible in a way to occupy the perpendicular edges of a cube containing the tumor inside. RESULTS: Mean duration of the cube method was shorter than the standard method (46 vs 61 minutes; P<.0001). Median numbers of skin and subcapsular entries were significantly smaller with the cube method (2 vs 4, P<.0001, and 2 vs 4, P<.0001, respectively). The rate of overall complications (total, major, and minor) was significantly lower in the cube method group compared with the standard method group (5.7% vs 13.7%; P=.013). Major complications occurred while using single markers only. The success rate was 98.9% for the cube method and 99.3% for the standard method. CONCLUSIONS: We propose a new technique of hepatic fiducial implantation that makes use of linked fiducials and involves fewer skin entries and shorter time of implantation. The technique is less complication-prone and is migration-resistant.

Stereotactic body radiation therapy for hepatocellular carcinoma: prognostic factors of local control, overall survival, and toxicity.

PURPOSE: Stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC) has been evaluated in several recent studies. The CyberKnife(®) is an SBRT system that allows for real-time tracking of the tumor. The purpose of this study was to evaluate the prognostic factors for local control and overall survival following this treatment. PATIENTS AND METHODS: 75 patients with 96 liver-confined HCC were treated with SBRT at the Oscar Lambret Comprehensive Cancer Center. Fiducials were implanted in the liver before treatment and were used as markers to track the lesion's movement. Treatment response was scored according to RECIST v1.1. Local control and overall survival were calculated using the Kaplan and Meier method. A stepwise multivariate analysis (Cox regression) of prognostic factors was performed for local control and overall survival. RESULTS: There were 67 patients with Child-Turcotte-Pugh (CTP) Class A and eight patients with CTP Class B. Treatment was administered in three sessions. A total dose of 40-45 Gy to the 80% isodose line was delivered. The median follow-up was 10 months (range, 3-49 months). The local control rate was 89.8% at 1 and 2 years. Overall survival was 78.5% and 50.4% at 1 and 2 years, respectively. Toxicity mainly consisted of grade 1 and grade 2 events. Higher alpha-fetoprotein (aFP) levels were associated with less favorable local control (HR=1.001; 95% CI [1.000, 1.002]; p=0.0063). A higher dose was associated with better local control (HR=0.866; 95% CI [0.753, 0.996]; p=0.0441). A Child-Pugh score higher than 5 was associated with worse overall survival (HR= 3.413; 95% CI [1.235, 9.435]; p=0.018). CONCLUSION: SBRT affords good local tumor control and higher overall survival rates than other historical controls (best supportive care or sorafenib). High aFP levels were associated with lesser local control, but a higher treatment dose improved local control.

Image-based response assessment of liver metastases following stereotactic body radiotherapy with respiratory tracking.

OBJECTIVE: To describe post-CyberKnife® imaging characteristics of liver metastases as an aid in assessing response to treatment, and a novel set of combined criteria (CC) as an alternative to response according to change in size (RECIST). SUBJECTS AND METHODS: Imaging data and medical records of 28 patients with 40 liver metastases treated with stereotactic body radiotherapy (SBRT) were reviewed. Tumor size, CT attenuation coefficient, and contrast enhancement of lesions were evaluated up to 2 years post SBRT. Rates of local control, progression-free survival, time to progression, and overall survival according to RECIST and CC were estimated. RESULTS: Complete response (CR) was 3.6% (95% CI: 0.1-18%) and 18% (95% CI: 6-37%) according to RECIST and combined criteria, respectively. Two progressive diseases and two partial responses according to RECIST were classified as CR by the combined criteria and one stable response according to RECIST was classified as progressive by CC (Stuart-Maxwell test, p = 0.012). The disease control rate was 60.7% (95% CI: 41-78%) by RECIST and 64% (95% CI: 44%-81%) by CC. CONCLUSION: Use of response criteria based on change in size alone in the interpretation of liver response to SBRT may be inadequate. We propose a simple algorithm with a combination of criteria to better assess tumor response. Further studies are needed to confirm their validity.

Prognostic factors affecting local control of hepatic tumors treated by Stereotactic Body Radiation Therapy.

PURPOSE: Robotic Stereotactic Body Radiation Therapy with real-time tumor tracking has shown encouraging results for hepatic tumors with good efficacy and low toxicity. We studied the factors associated with local control of primary or secondary hepatic lesions post-SBRT. METHODS AND MATERIALS: Since 2007, 153 stereotactic liver treatments were administered to 120 patients using the CyberKnife® System. Ninety-nine liver metastases (72 patients), 48 hepatocellular carcinomas (42 patients), and six cholangiocarcinomas were treated. On average, three to four sessions were delivered over 12 days. Twenty-seven to 45 Gy was prescribed to the 80% isodose line. Margins consisted of 5 to 10 mm for clinical target volume (CTV) and 3 mm for planning target volume (PTV). RESULTS: Median size was 33 mm (range, 5-112 mm). Median gross tumor volume (GTV) was 32.38 cm3 (range, 0.2-499.5 cm3). Median total dose was 45 Gy in three fractions. Median minimum dose was 27 Gy in three fractions. With a median follow-up of 15.0 months, local control rates at one and two years were 84% and 74.6%, respectively. The factors associated with better local control were lesion size < 50 mm (p = 0.019), GTV volume (p < 0.05), PTV volume (p < 0.01) and two treatment factors: a total dose of 45 Gy and a dose-per-fraction of 15 Gy (p = 0.019). CONCLUSIONS: Dose, tumor diameter and volume are prognostic factors for local control when a stereotactic radiation therapy for hepatic lesions is considered. These results should be considered in order to obtain a maximum therapeutic efficacy.

Robotic image-guided reirradiation of lateral pelvic recurrences: preliminary results.

BACKGROUND: The first-line treatment of a pelvic recurrence in a previously irradiated area is surgery. Unfortunately, few patients are deemed operable, often due to the location of the recurrence, usually too close to the iliac vessels, or the associated surgical morbidity. The objective of this study is to test the viability of robotic image-guided radiotherapy as an alternative treatment in inoperable cases. METHODS: Sixteen patients previously treated with radiotherapy were reirradiated with CyberKnife® for lateral pelvic lesions. Recurrences of primary rectal cancer (4 patients), anal canal (6), uterine cervix cancer (4), endometrial cancer (1), and bladder carcinoma (1) were treated. The median dose of the previous treatment was 45 Gy (EqD2 range: 20 to 96 Gy). A total dose of 36 Gy in six fractions was delivered with the CyberKnife over three weeks. The responses were evaluated according to RECIST criteria. RESULTS: Median follow-up was 10.6 months (1.9 to 20.5 months). The actuarial local control rate was 51.4% at one year. Median disease-free survival was 8.3 months after CyberKnife treatment. The actuarial one-year survival rate was 46%. Acute tolerance was limited to digestive grade 1 and 2 toxicities. CONCLUSIONS: Robotic stereotactic radiotherapy can offer a short and well-tolerated treatment for lateral pelvic recurrences in previously irradiated areas in patients otherwise not treatable. Efficacy and toxicity need to be evaluated over the long term, but initial results are encouraging.

Pyelonephritis xanthogranulomatous in childhood: case report and literature review.

BACKGROUND: Xanthogranulomatous pyelonephritis (XGP) is a specific form of chronic inflammatory kidney disease rarely seen in children. The Symptoms are often vague and non-specific AIM: the aim of this paper is to return the particularities of imaging features in xanthogranulomatous pyelonephritis, insisting on differential diagnosis with renal tumors, especially in case of no renal stone or tract obstruction evidence. CASE: We report a case of xanthogranulomatous pyelonephritis in a 2-year-old boy involving the lower renal pole which demonstrates the diagnostic difficulties encountered in this disease CONCLUSION: Xanthogranulomatous pyelonephritis is a rare condition in children and should be included in the differential diagnosis of a child presenting a renal mass.