Intra- and inter-fractional liver and lung tumor motions treated with SBRT under active breathing control

Purpose

To assess intra‐ and inter‐fractional motions of liver and lung tumors using active breathing control (ABC).

Methods and Materials

Nineteen patients with liver cancer and 15 patients with lung cancer treated with stereotactic body radiotherapy (SBRT) were included in this retrospective study. All patients received a series of three CTs at simulation to test breath‐hold reproducibility. The centroids of the whole livers and of the lung tumors from the three CTs were compared to assess intra‐fraction variability. For 15 patients (8 liver, 7 lung), ABC‐gated kilovoltage cone‐beam CTs (kV‐CBCTs) were acquired prior to each treatment, and the centroids of the whole livers and of the lung tumors were also compared to those in the planning CTs to assess inter‐fraction variability.

Results

Liver intra‐fractional systematic/random errors were 0.75/0.39 mm, 1.36/0.97 mm, and 1.55/1.41 mm at medial‐lateral (ML), anterior‐posterior (AP), and superior‐inferior (SI) directions, respectively. Lung intra‐fractional systematic/random errors were 0.71/0.54 mm (ML), 1.45/1.10 mm (AP), and 3.95/1.93 mm (SI), respectively. Substantial intra‐fraction motions (>3 mm) were observed in 26.3% of liver cancer patients and in 46.7% of lung cancer patients. For both liver and lung tumors, most inter‐fractional systematic and random errors were larger than the corresponding intra‐fractional errors. However, these inter‐fractional errors were mostly corrected by the treatment team prior to each treatment based on kV CBCT‐guided soft tissue alignment, thereby eliminating their effects on the treatment planning margins.

Conclusions

Intra‐fractional motion is the key to determine the planning margins since inter‐fractional motion can be compensated based on daily gated soft tissue imaging guidance of CBCT. Patient‐specific treatment planning margins instead of recipe‐based margins were suggested, which can benefit mostly for the patients with small intra‐fractional motions.

Neoadjuvant chemoradiation for non-metastatic pancreatic cancer increases margin-negative and node-negative rates at resection

OBJECTIVE

To compare neoadjuvant to adjuvant chemoradiation in non-metastatic pancreatic cancer patients.

METHODS

Single-institution data were obtained for patients with non-metastatic pancreatic cancer treated with concurrent chemoradiation from 2011 to 2014. Univariate analyses were performed to evaluate clinical and pathological outcomes.

RESULTS

Fifty-two well-matched patients were enrolled (21 underwent neoadjuvant chemoradiation, 11 with adjuvant chemoradiation and 20 in the definitive group). Median tumor size was 2.6 cm pretreatment and 2.5 cm after neoadjuvant chemoradiation but 3.2 cm on pathology, with a treatment effect in 95.2% of specimens. Clinical node positivity at diagnosis for neoadjuvant and adjuvant chemoradiation groups was similar (28.6% vs 27.3%, P = 0.12). Of the 36 neoadjuvant patients, 21 (58.3%) underwent complete resection. In the neoadjuvant vs adjuvant chemoradiation groups, positive margins were decreased (4.8% vs 63.6%, P < 0.001), as was pathological nodal positivity (23.8% vs 90.9%, P < 0.001). After a median follow-up of 13.3 months, locoregional control for neoadjuvant and adjuvant chemoradiation was 7.7 and 7.2 months, respectively (P = 0.12) and the definitive group was 1.2 months (P = 0.014 compared with the surgical cohort). One-year overall survival was better with neoadjuvant than with adjuvant chemoradiation but this was not significant (94% vs 82%, P = 0.20); 1-year survival for the definitive group was 59% (P = 0.03 compared with the surgical cohort).

CONCLUSIONS

Neoadjuvant chemoradiation remains a promising approach for non-metastatic pancreatic cancer for improving resectability and pathological and clinical findings. Computed tomography may not fully demonstrate the effectiveness of neoadjuvant treatment.

Influence of radiation treatment technique on outcome and toxicity in anal cancer

Objective

Intensity-modulated radiation therapy (IMRT) has largely supplanted three-dimensional conformal radiation (3D-CRT) for definitive anal cancer treatment due to decreased toxicity and potentially improved outcomes. Convincing data demonstrating its advantages, however, remain limited. We compared outcomes and toxicity with concurrent chemotherapy and IMRT vs 3D-CRT for anal cancer.

Methods

We performed a single-institution retrospective review of patients treated with IMRT or 3D-CRT as part of definitive mitomycin-C/5-fluorouricil-based chemoradiation for anal cancer from January 2003 to December 2012.

Results

One hundred sixty-five patients were included, with 61 and 104 receiving IMRT and 3D-CRT, respectively. Overall, 92.7% had squamous cell carcinoma. The mean initial pelvic dose was 48.3 and 44 Gy for IMRT and 3D-CRT, respectively. Complete response, partial response, and disease progression rates were similar (IMRT 83.6, 8.2, 8.2%; 3D-CRT 85.6, 6.7, 7.7%; p = 0.608, p = 0.728, p = 0.729). There was no significant difference in overall survival (p = 0.971), event-free survival (p = 0.900), or local or distant recurrence rates (p = 0.118, p = 0.373). IMRT caused significantly less acute grade 1–2 incontinence (p = 0.035), grade 3–4 pain (p = 0.033), and fatigue (p = 0.030). IMRT patients had significantly fewer chronic post-treatment toxicities (p = 0.008), outperforming 3D-CRT in six of eight toxicities reviewed. Though total treatment length was comparable (43.6 and 44.5 days), IMRT recipients had fewer (27.9 vs 41.3% of patients, p = 0.89), shorter treatment breaks (mean 2.9 vs 4.1 days, p = 0.229).

Conclusion

This report represents the largest series directly comparing concurrent chemotherapy with IMRT vs 3D-CRT for definitive treatment of anal cancer. IMRT significantly reduced acute and post-treatment toxicities and allowed for safe and effective pelvic dose escalation.

ACR Appropriateness Criteria® Resectable Pancreatic Cancer

Management of resectable pancreatic adenocarcinoma continues to present a challenge due to a paucity of high-quality randomized studies. Administration of adjuvant chemotherapy is widely accepted due to the high risk of systemic spread associated with pancreatic adenocarcinoma, but the role of radiation therapy is less clear. This paper reviews literature associated with resectable pancreatic cancer to include prognostic factors to aid in the selection of patients appropriate for adjuvant therapies. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Roles and Activities of International Organizations After the Fukushima Accident

After the March 2011 Fukushima Daiichi Nuclear Power Plant accident, overseas experts and representatives of international organizations visited Japan to provide advice, technical support, and resources. Several international meetings on radiological protection and health issues have since been held in Fukushima to provide further advice. The content discussed has changed alongside local developments in health-related issues from radiation health effects and radiological protection to risk communication and psychological, public health, and social issues. The support of international organizations and experts has been valuable in implementing public health and support programs in Fukushima. The Fukushima accident showed that after a nuclear accident, authorities need to balance the risks of radiation with other health effects and develop programs to mitigate the overall effects on health (whole-health management), but there was little evidence of the importance of this at the time. Future research should examine international collaboration to assess this.

Academic Responses to Fukushima Disaster

Since radiation accidents, particularly nuclear disasters, are rarer than other types of disasters, a comprehensive radiation disaster medical curriculum for them is currently unavailable. The Fukushima compound disaster has urged the establishment of a new medical curriculum in preparation for any future complex disaster. The medical education will aim to aid decision making on various health risks for workers, vulnerable people, and residents addressing each phase in the disaster. Herein, we introduce 3 novel educational programs that have been initiated to provide students, professionals, and leaders with the knowledge of and skills to elude the social consequences of complex nuclear disasters. The first program concentrates on radiation disaster medicine for medical students at the Fukushima Medical University, together with a science, technology, and society module comprising various topics, such as public risk communication, psychosocial consequences of radiation anxiety, and decision making for radiation disaster. The second program is a Phoenix Leader PhD degree at the Hiroshima University, which aims to develop future leaders who can address the associated scientific, environmental, and social issues. The third program is a Joint Graduate School of Master’s degree in the Division of Disaster and Radiation Medical Sciences at the Nagasaki University and Fukushima Medical University.

ACR Appropriateness Criteria® Borderline and Unresectable Pancreas Cancer

The American College of Radiology Appropriateness Criteria® are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. The panel reviewed the pertinent literature and voted on five variants to establish appropriate recommended treatment of borderline and unresectable pancreatic cancer. The guidelines reviewed the use of radiation, chemotherapy, and surgery. Radiation technique, dose, and targets were evaluated, as was the recommended chemotherapy, administered either alone or concurrently with radiation. This report will aid clinicians in determining guidelines for the optimal treatment of borderline and unresectable pancreatic cancer.

Predictors of mortality in patients with cardiogenic shock treated with primary percutaneous coronary intervention and intra-aortic balloon counterpulsation

BACKGROUND

Cardiogenic shock remains the most serious complication of patients hospitalized with acute myocardial infarction (AMI). Early revascularization is the cornerstone of invasive therapy, while mechanical support with intra-aortic balloon pump (IABP) is debatable. From our institutional shock registry we sought to determine predictors of in-hospital mortality-including the aspect of IABP timing-and to develop a clinical risk score for shock patients with AMI.

METHODS

From January 2005 till December 2010, 102 patients with cardiogenic shock due to AMI treated with primary percutaneous coronary intervention (PCI) and IABP were analyzed. Univariate and multivariate logistic regression analyses were used to identify independent predictors of in-hospital mortality. Logistic regression analysis and receiver-operating curves were used to generate a mortality risk score.

RESULTS

The mean age of the cohort was 70.1 ± 11.0 years and 70 % were men. One third of patients had a non-ST segment elevation myocardial infarction and 30 % had to be resuscitated before coronary intervention. Mean left ventricular ejection fraction was 25 %. After admission, 23 % of patients developed an acute renal failure and 10 % needed renal dialysis during hospital stay. In 52 % of patients IABP therapy was initiated after primary PCI, while the remaining patients had an IABP-assisted primary PCI. All-cause in-hospital mortality was 40.2 %. Using multivariate analysis, age (odds ratio [OR] 1.08, p = 0.006), resuscitation before PCI (OR 3.46, p = 0.045), vasopressor use (OR 7.88, p = 0.003), acute renal failure (OR 11.18, p = 0.001), and IABP implantation after PCI (OR 4.36, p = 0.011) were independently associated with in-hospital mortality. Based on these predictors, a mortality-risk score was calculated as follows: 1.5 × IABP timing before PCI + 0.1 × age + resuscitation before PCI + 2 × vasopressor use + 2.5 × acute renal failure. Using a cut-off value of 10.4, this score had a specificity of 83 % and a sensitivity of 82 % for prediction of in-hospital death.

CONCLUSIONS

We identified age, vasopressor use, resuscitation before PCI, acute renal failure and IABP implantation after PCI as independent predictors of in-hospital mortality in patients with cardiogenic shock due to AMI. The timing of IABP insertion was the only modifiable factor predicting in-hospital mortality in our cohort. Consequently, balloon pumping should be started before PCI to improve outcome of cardiogenic shock patients.

Significant aortic regurgitation after transfemoral aortic valve implantation: patients' gender as independent risk factor

AIM

Significant aortic regurgitation (AR) has been reported in 20% of patients undergoing transfemoral aortic valve implantation (TAVI) and has been associated with increased mortality. Depending on the population included and the type of implanted prosthesis, several anatomical and procedural factors have been linked with increased risk of post-TAVI AR. While the impact of patients' gender on this complication, is still contradictory. We sought to assess the impact of patients' gender on the risk of significant AR after TAVI.

METHODS

We included 323 consecutive patients (136 men) who underwent transfemoral implantation of either self-expandable or balloon-expandable prostheses for treatment of symptomatic aortic stenosis.

RESULTS

After TAVI 52 patients (16.1%) had AR grade ≥ 2/4 as evaluated by angiography. They were more frequently male (59.6% vs. 40.4%, P = 0.005), received self-expandable (94.2% vs. 63.5%, P < 0.001) and bigger size prostheses (28 ± 1.9 vs. 27.3 ± 2.1 mm, P = 0.028) and had reduced left ventricular ejection fraction (45.3% ± 14.2% vs. 51.2% ± 13%, P = 0.003) compared to patients with AR grade < 2/4 (N. = 271). In multivariate analysis, men (OR 2.13 [95% CI, 1.08-4.18]) and prosthesis type (OR 13.17 [95% CI, 3.24-57.97]) were identified as independent predictors of AR grade ≥ 2/4.

CONCLUSION

Alongside with the implantation of self-expandable aortic prosthesis, male gender independently increases the risk of significant AR in patients undergoing TAVI. The question if this finding is related to gender biology itself or to gender-related aggregation of subtle anatomic characteristics needs further investigations.

ACR Appropriateness Criteria® Local Excision in Early Stage Rectal Cancer

Low anterior resection or abdominoperineal resection are considered standard treatments for early rectal cancer but may be associated with morbidity in selected patients who are candidates for early distal lesions amenable to local excision (LE). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. The panel recognizes the importance of accurate staging to identify patients who may be candidates for a LE approach. Patients who may be candidates for LE alone include those with small, low-lying T1 tumors, without adverse pathologic features. Several surgical approaches can be utilized for LE however none include lymph node evaluation. Adjuvant radiation±chemotherapy may be warranted depending on the risk of nodal metastases. Patients with high-risk T1 tumors, T2 tumors not amenable to radical surgery may also benefit from adjuvant treatment; however, patients with positive margins or T3 lesions should be offered abdominoperineal resection or low anterior resection. Neoadjuvant radiation±chemotherapy followed by LE in higher risk patients results in excellent local control, but it is not clear if this approach reduces recurrence rates over surgery alone.

ACR Appropriateness Criteria® Resectable Stomach Cancer

For resectable gastric cancer, perioperative chemotherapy or adjuvant chemoradiation with chemotherapy are standards of care. The decision making for adjuvant therapeutic management can depend on the stage of the cancer, lymph node positivity, and extent of surgical resection. After gastric cancer resection, postoperative chemotherapy combined with chemoradiation should be incorporated in cases of D0 lymph node dissection, positive regional lymph nodes, poor clinical response to induction chemotherapy, or positive margins. In the setting of a D2 lymph node dissection, especially those with negative regional lymph nodes, adjuvant chemotherapy alone could be considered. The American College of Radiology (ACR) Appropriateness Criteria® are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review includes an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Patterns of cancer recurrence in localized resected hepatocellular carcinoma

BACKGROUND

Tumor resection in non-metastatic hepatocellular carcinoma (HCC) patients with adequate liver reserve offers a potential cure, but has a high 5-year recurrence rate. We analyzed the patterns of cancer relapse after partial hepatectomy to guide post-operative management.

METHODS

A total of 144 HCC patients (1996-2011) after partial hepatectomy were reviewed. Statistical correlations were determined using univariate and partition analyses.

RESULTS

A median follow-up of 20 months showed recurrence in 71 (49%) patients, and the median time to recurrence was 11.9 months. Vascular invasion (P<0.01) and number of lesions (P<0.01) predicted for recurrence. Histologic grade was not correlated with recurrence. Twenty-two (31%) patients developed both surgical margin (SM) and concurrent intrahepatic recurrences, and 28 (40%) had non-SM intrahepatic recurrences with no other signs of recurrence. On partition analysis, the risk of marginal recurrence in patients with SM <1 mm and SM ≥1 mm was 35% and 13.5% respectively. Approximately 57% of patients with intrahepatic recurrence had recurrence ≤2.5 cm from SM.

CONCLUSIONS

Intrahepatic recurrence after partial hepatectomy is common and is significantly associated with vascular invasion and tumor stage. About 57% of patients with intrahepatic relapse had a recurrence close (≤2.5 cm) to the SM. Additionally, patients with SM <1 mm have a higher recurrence rate and may benefit from adjuvant local therapy.

Potential systematic uncertainties in IGRT when FBCT reference images are used for pancreatic tumors

The purpose of this study was to quantify the systematic uncertainties resulting from using free breathing computed tomography (FBCT) as a reference image for image‐guided radiation therapy (IGRT) for patients with pancreatic tumors, and to quantify the associated dosimetric impact that resulted from using FBCT as reference for IGRT. Fifteen patients with implanted fiducial markers were selected for this study. For each patient, a FBCT and an average intensity projection computed tomography (AIP) created from four‐dimensional computed tomography (4D CT) were acquired at the simulation. The treatment plan was created based on the FBCT. Seventy‐five weekly kilovoltage (kV) cone‐beam computed tomography (CBCT) images (five for each patient) were selected for this study. Bony alignment without rotation correction was performed 1) between the FBCT and CBCT, 2) between the AIP and CBCT, and 3) between the AIP and FBCT. The contours of the fiducials from the FBCT and AIP were transferred to the corresponding CBCT and were compared. Among the 75 CBCTs, 20 that had >3 mm differences in centers of mass (COMs) in any directions between the FBCT and AIP were chosen for further dosimetric analysis. These COM discrepancies were converted into isocenter shifts in the corresponding planning FBCT, and dose was recalculated and compared to the initial FBCT plans. For the 75 CBCTs studied, the mean absolute differences in the COMs of the fiducial markers between the FBCT and CBCTs were 3.3 mm±2.5 mm,3.5 mm±2.4 mm, and 5.8 mm±4.4 mm in the right–left (RL), anterior–posterior (AP), and superior–inferior (SI) directions, respectively. Between the AIP and CBCTs, the mean absolute differences were 3.2 mm±2.2 mm,3.3 mm±2.3 mm, and 6.3 mm±5.4 mm. The absolute mean discrepancies in these COMs shifts between FBCT/CBCT and AIP/CBCT were 1.1 mm±0.8 mm,1.3 mm±0.9 mm, and 3.3 mm±2.6 mm in RL, AP, and SI, respectively. This represented a potential systematic error. For the 20 CBCTs that had COM discrepancies >3 mm in any direction, the average reduction in planning target volume (PTV) coverage (PTV volume receiving 100% of prescription dose) was 5.3%±3.1% (range: 0.7%–12.8%). Using FBCT as a reference for IGRT may introduce potential interfractional systematic COM shifts if the FBCT is acquired at a different breathing phase than the average breathing phase. The potential systematic error could be significant in the SI direction and varied among patients for the other directions. AIP is a better choice of reference image set for IGRT in order to correct interfractional variations due to respiratory motion and nonrespiratory organ displacement.

PACS numbers: 87.55.D, 87.55.dk, 87.55.km