Unilateral cochlea sparing in locoregionally advanced head and neck cancer: a planning study

Background

Cochlea sparing can reduce late ototoxicity in head and neck cancer patients treated with cisplatin-based radiochemotherapy. In this situation, a mean cochlear dose (MCD) constraint of 10?Gy has been suggested by others based on the dose–effect relationship of clinical data. We aimed to investigate whether this is feasible for primary and postoperative radiochemotherapy in locoregionally advanced tumors without compromising target coverage.

Patients and methods

Ten patients treated with definitive and ten patients treated with adjuvant intensity-modulated radiotherapy (IMRT) and concurrent chemotherapy were investigated. The cochleae and a planning risk volume (PRV) with a 3?mm margin were newly delineated, whereas target volumes and other organs at risk were not changed. The initial plan was recalculated with a constraint of 10?Gy (MCD) on the low-risk side. The quality of the resulting plan was evaluated using the difference in the equivalent uniform dose (EUD).

Results

A unilateral MCD of below 10?Gy could be achieved in every patient. The mean MCD was 6.8?Gy in the adjuvant cohort and 7.6?Gy in the definitive cohort, while the non-spared side showed a mean MCD of 18.7 and 30.3?Gy, respectively. The mean PRV doses were 7.8 and 8.4?Gy for the spared side and 18.5 and 29.8?Gy for the non-spared side, respectively. The mean EUD values of the initial and recalculated plans were identical. Target volume was not compromised.

Conclusion

Unilateral cochlea sparing with an MCD of less than 10?Gy is feasible without compromising the target volume or dose coverage in locoregionally advanced head and neck cancer patients treated with IMRT. A prospective evaluation of the clinical benefit of this approach as well as further investigation of the dose–response relationship for future treatment modification appears promising.

     

Accuracy assessment of a potential clinical use of navigation-guided intra-operative liver metastasis brachytherapy—a planning study

For patients with inoperable liver metastases, intra-operative liver high dose-rate brachytherapy (HDR-BT) is a promising technology enabling delivery of a high radiation dose to the tumor, while sparing healthy tissue. Liver brachytherapy has been described in the literature as safe and effective for the treatment of primary or secondary hepatic malignancies. It is preferred over other ablative techniques for lesions that are either larger than 4?cm or located in close proximity to large vessels or the common bile duct. In contrast to external beam radiation techniques, organ movements do not affect the size of the irradiated volume in intra-operative HDR-BT and new technical solutions exist to support image guidance for intra-operative HDR-BT. We have retrospectively analyzed anonymized CT datasets of 5 patients who underwent open liver surgery (resection and/or ablation) in order to test whether the accuracy of a new image-guidance method specifically adapted for intra-operative HDR-BT is high enough to use it in similar situations and whether patients could potentially benefit from navigation-guided intra-operative needle placement for liver HDR-BT.     

A treatment planning study of prone vs. supine positions for locally advanced rectal carcinoma

Purpose

To ascertain the optimal radiation technique and radiation position for the neoadjuvant radiotherapy of patients with rectal cancer.

Materials and methods

Treatment plans with similar dose objectives were generated for 20 selected patients. Dosimetric comparison was performed between prone and supine positions and between different radiation techniques. Dosimetric indices for the target volume and organs at risk (OAR) as well as normal tissue complication probability (NTCP) of late small bowel toxicity were analyzed.

Results

The helical tomotherapy (HT) in the prone position provided the optimal dose homogeneity in the target volume with the value of 0. Superior conformity values were obtained for Sliding Window (SW), Rapid Arc (RA) and HT compared to three-dimensional conformal radiotherapy (3D-CRT) techniques. All of the techniques showed dose reduction to OAR in the high-dose area in prone position versus supine position. Pairwise comparison revealed significantly higher small bowel protection by RA in the prone position in the high-dose area (V75, V45Gy). Similarly, superior bladder sparing was found for 3D-CRT in the prone position at higher doses (V50, V75). More healthy tissue in the radiation volume was involved by application of 3D-CRT with no relevant difference between positions. The mean values of NTCP for the small bowel did not show clinically meaningful variation between the techniques.

Conclusion

All techniques provided superior sparing of OAR in the prone position. At higher radiation doses, treatment in prone position resulted in significant OAR protection, especially concerning small bowel sparing by RA and bladder sparing by 3D CRT.

     

Evaluation of bi-objective treatment planning for high-dose-rate prostate brachytherapy—A retrospective observer study

PurposeBi-objective treatment planning for high-dose-rate prostate brachytherapy is a novel treatment planning method with two separate objectives that represent target coverage and organ-at-risk sparing. In this study, we investigated the feasibility and plan quality of this method by means of a retrospective observer study.Methods and MaterialsCurrent planning sessions were recorded to configure a bi-objective optimization model and to assess its applicability to our clinical practice. Optimization software, GOMEA, was then used to automatically generate a large set of plans with different trade-offs in the two objectives for each of 18 patients treated with high-dose-rate prostate brachytherapy. From this set, five plans per patient were selected for comparison to the clinical plan in terms of satisfaction of planning criteria and in a retrospective observer study. Three brachytherapists were asked to evaluate the blinded plans and select the preferred one.ResultsRecordings demonstrated applicability of the bi-objective optimization model to our clinical practice. For 14/18 patients, GOMEA plans satisfied all planning criteria, compared with 4/18 clinical plans. In the observer study, in 53/54 cases, a GOMEA plan was preferred over the clinical plan. When asked for consensus among observers, this ratio was 17/18 patients. Observers highly appreciated the insight gained from comparing multiple plans with different trade-offs simultaneously.ConclusionsThe bi-objective optimization model adapted well to our clinical practice. GOMEA plans were considered equal or superior to the clinical plans. In addition, presenting multiple high-quality plans provided novel insight into patient-specific trade-offs.     

Laparoscopic Sleeve Gastrectomy: A Radiological Guide to Common Postsurgical Failure

Laparoscopic sleeve gastrectomy is one of the most common bariatric procedures worldwide. It has recently gained in popularity because of a low complication rate, satisfactory resolution of comorbidities, and excellent weight loss outcome. This article reviews the surgical technique, expected postsurgical imaging appearance, and imaging findings of common complications after laparoscopic sleeve gastrectomy. Understanding of the surgical technique of laparoscopic sleeve gastrectomy and of the normal postsurgical anatomy allows accurate interpretation of imaging findings in cases of insufficient weight loss, weight regain, and postsurgical complications.     

Node-positive left-sided breast cancer: does VMAT improve treatment plan quality with respect to IMRT?

Purpose

The aim of the present work was to explore plan quality and dosimetric accuracy of intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) for lymph node-positive left-sided breast cancer.

Methods

VMAT and IMRT plans were generated with the Pinnacle³ V9.0 treatment planning system for 10 lymph node-positive left-sided breast cancer patients. VMAT plans were created using a single arc and IMRT was performed with 4 beams using 6, 10, and 15 MV photon energy, respectively. Plans were evaluated both manually and automatically using ArtiView?. Dosimetric plan verification was performed with a 2D ionization chamber array placed in a full scatter phantom.

Results

Photon energy had no significant influence on plan quality for both VMAT and IMRT. Large variability in low doses to the heart was found due to patient anatomy (range V_5 Gy 26.5–95?%). Slightly more normal tissue dose was found for VMAT (e.g., V_Tissue30%?=?22?%) than in IMRT (V_Tissue30%?=?18?%). The manual and ArtiView? plan evaluation coincided very accurately for most dose metrics (difference <?1?%). In VMAT, 96.7?% of detector points passed the 3?%/3 mm gamma criterion; marginally better accuracy was found in IMRT (98.3?%).

Conclusion

VMAT for node-positive left-sided breast cancer retains target homogeneity and coverage when compared to IMRT and allows maximum doses to organs at risk to be reduced. ArtiView? enables fast and accurate plan evaluation.     

IMRT in a Pregnant Patient: How to Reduce the Fetal Dose?

The purpose of our study was to find a solution for fetal dose reduction during head-and-neck intensity modulated radiation therapy (IMRT) of a pregnant patient. The first step was optimization of the IMRT treatment plan with as few monitor units (MUs) as possible, while maintaining an acceptable dose distribution. The peripheral dose originating from the final IMRT plan was measured at distances reaching from the most proximal to the most distal fetal position, along the accelerator's longitudinal axis, using an anthropomorphic phantom extended with water-equivalent plastic. The measured peripheral dose was divided into leakage, and internal and collimator scatter, to find the degree to which each component influences the peripheral dose to build an appropriate shield. Collimator scatter was the greatest contributor to the peripheral dose throughout the range of the growing fetus. A shield was built and placed beneath the accelerator head, extending caudally from the field edge, to function as an extra collimator jaw. This shield reduced the fetal dose by a factor of 3.5. The peripheral dose components were also measured for simple rectangular fields and also here the collimator scatter was the greatest contributor to the peripheral dose. Therefore, the shielding used for the IMRT treatment of our patient could also be used when shielding in conventional radiotherapy. It is important for a radiation therapy department to be prepared for treatment of a pregnant patient to shield the fetus efficiently.     

Computed tomographic peritoneography prior to intraperitoneal chemotherapy in advanced müllerian cancer: a pilot study

ObjectiveThe objective of this study was to utilize computed tomographic peritoneography (CTP) to assess distribution prior to intraperitoneal chemotherapy for advanced müllerian cancer.MethodsNineteen patients were submitted to CTP. A novel 6-point peritoneal distribution index was developed and applied to the patients prospectively.ResultsThe median peritoneal distribution index was 6 (range, 4–6). The most common region for incomplete peritoneal distribution correlated to the right subphrenic space.ConclusionFurther studies are needed to determine the impact of inadequate distribution on recurrence and survival.     

Automated percutaneous lumbar discectomy: technique,indications and clinical follow-up in over 1000 patients

This paper summarises my experience, over 14 years, treating over 1350 patients suffering from lumbar disc pathology, using minimally invasive intradiscal decompressive percutaneous techniques. The vast majority underwent the method introduced by Onik in 1985, referred to as "automated" since it involves a mechanical probe, working by a "suction and cutting" action for removal of the nucleus pulposus. Postoperative follow-up of at least 6 months was available for 1047 patients aged 15–92 years, who underwent this procedure up to June 2002. Results, based on a patient satisfaction, have been good in 58% of patients at 2 months and in 67.5% at 6 months; they have been particularly favourable in some subgroups such as elderly people (79.5% of excellent or good results), patients previously operated upon (78%) and those with "discogenic" low back pain (79%). Complication rates have been extremely low (less than 1%) and all complications cleared up without sequelae. In comparison with other percutaneous disc treatments, Onik's achieves the best compromise between clinical efficacy, comfort for the patient and low invasiveness.     

Effect of continuous positive airway pressure administration during lung stereotactic ablative radiotherapy: a comparative planning study

Purpose

By increasing lung volume and decreasing respiration-induced tumour motion amplitude, administration of continuous positive airway pressure (CPAP) during stereotactic ablative radiotherapy (SABR) could allow for better sparing of the lungs and heart. In this study, we evaluated the effect of CPAP on lung volume, tumour motion amplitude and baseline shift, as well as the dosimetric impact of the strategy.

Methods

Twenty patients with lung tumours referred for SABR underwent 4D-computed tomography (CT) scans with and without CPAP (CPAP/noCPAP) at two timepoints (T0/T1). First, CPAP and noCPAP scans were compared for lung volume, tumour motion amplitude, and baseline shift. Next, CPAP and noCPAP treatment plans were computed and compared for lung dose parameters (mean lung dose (MLD), lung volume receiving 20 Gy (V_20Gy), 13 Gy (V_13Gy), and 5 Gy (V_5Gy)) and mean heart dose (MHD).

Results

On average, CPAP increased lung volume by 8.0% (p?<?0.001) and 6.3% (p?<?0.001) at T0 and T1, respectively, but did not change tumour motion amplitude or baseline shift. As a result, CPAP administration led to an absolute decrease in MLD, lung V_20Gy, V_13Gy and V_5Gy of 0.1?Gy (p?=?0.1), 0.4% (p?=?0.03), 0.5% (p?=?0.04) and 0.5% (p?=?0.2), respectively, while having no significant influence on MHD.

Conclusions

In patients referred for SABR for lung tumours, CPAP increased lung volume without modifying tumour motion or baseline shift. As a result, CPAP allowed for a slight decrease in radiation dose to the lungs, which is unlikely to be clinically significant.

     

Haralick’s texture features for the prediction of response to therapy in colorectal cancer: a preliminary study

Purpose

Haralick features Texture analysis is a recent oncologic imaging biomarker used to assess quantitatively the heterogeneity within a tumor. The aim of this study is to evaluate which Haralick’s features are the most feasible in predicting tumor response to neoadjuvant chemoradiotherapy (CRT) in colorectal cancer.

Materials and Methods

After MRI and histological assessment, eight patients were enrolled and divided into two groups based on response to neoadjuvant CRT in complete responders (CR) and non-responders (NR). Oblique Axial T2-weighted MRI sequences before CRT were analyzed by two radiologists in consensus drawing a ROI around the tumor. 14 over 192 Haralick’s features were extrapolated from normalized gray-level co-occurrence matrix in four different directions. A dedicated statistical analysis was performed to evaluate distribution of the extracted Haralick’s features computing mean and standard deviation.

Results

Pretreatment MRI examination showed significant value (p < 0.05) of 5 over 14 computed Haralick texture. In particular, the significant features are the following: concerning energy, contrast, correlation, entropy and inverse difference moment.

Conclusions

Five Haralick’s features showed significant relevance in the prediction of response to therapy in colorectal cancer and might be used as additional imaging biomarker in the oncologic management of colorectal patients.

     

Response to neoadjuvant chemotherapy for breast cancer judged by PERCIST – multicenter study in Japan

Purpose

The purpose of this study was to evaluate therapeutic response to neoadjuvant chemotherapy (NAC) and predict breast cancer recurrence using Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST).

Materials and methods

Fifty-nine breast cancer patients underwent fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) before and after NAC prior to planned surgical resection. Pathological complete response (pCR) of the primary tumor was evaluated using PERCIST, while effects of clinicopathological factors on progression-free survival (PFS) were examined using log-rank and Cox methods.

Results

Fifty-six patients and 54 primary tumors were evaluated. Complete metabolic response (CMR), partial metabolic response, stable metabolic disease, and progressive metabolic disease were seen in 45, 7, 3, and 1 patients, respectively, and 43, 7, 3, and 1 primary tumors, respectively. Eighteen (33.3%) of the 54 primary tumors showed pCR. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PERCIST to predict pCR were 100% (18/18), 30.6% (11/36), 41.9% (18/43), 100% (11/11), and 53.7% (29/54), respectively. An optimal percent decrease in peak standardized uptake value for a primary tumor corrected for lean body mass (SULpeak) of 84.3% was found to have a sensitivity of 77.8% (14/18), specificity of 77.8% (28/36), PPV of 63.6% (14/22), NPV of 87.5% (28/32), and accuracy of 77.8% (42/54). Seven (12.5%) of the 56 patients developed recurrent disease (median follow-up 28.1 months, range 11.4–96.4 months). CMR (p?=?0.031), pCR (p?=?0.024), and early TNM stage (p?=?0.033) were significantly associated with longer PFS.

Conclusion

PERCIST is useful for predicting pathological response and prognosis following NAC in breast cancer patients. However, FDG-PET/CT showed a tendency toward underestimation of the residual tumor, and relatively low specificity and PPV of PERCIST showed that a combination of other imaging modalities would still be needed to predict pCR.

     

Case study: Lesions due to forced ritual scarification in Cameroon – A warning from cultural anthropology to forensic medicine

Asylum seekers and refugees are constantly increasing worldwide because of human rights’ violations and political-related abuses. As a result, some of them show scars due to torture and other forms of maltreatments. In addition, they may also present scars due to ethnical practices, namely ritual scarifications.This case study presents a victim who did not give consent to perform such ethnical practices on her body. The authors aim to enlighten the difficulty to understand the origin and the purpose of these specific injuries and the importance to know how to distinguish them from other forms of abuse. Indeed, it appears that such lesions follow a cultural path, meaning that the lesions are performed methodically and may show macroscopic differences compared to others. The story narrated by the victim can be helpful for the experts’ assessment, regardless, they may present memory-loss issues. This represents the value of a correct injuries’ diagnosis and the importance of cultural anthropology-related analyses. The cultural and social background are relevant since the injuries have their own signification because of their symbolism. Therefore, a multidisciplinary approach with a cultural anthropologist may have the possibility to help the forensic experts in understanding and interpreting such stories fostering their ability to better assess asylum seekers stories and their reliability.     

In vivo dosimetry in gynecological applications—A feasibility study

PurposeTo investigate the feasibility of in vivo dosimetry using microMOSFET dosimeters in patients treated with brachytherapy using two types of gynecological applicators.Methods and MaterialsIn this study, a microMOSFET was placed in an empty needle of an Utrecht Interstitial Fletcher applicator or MUPIT (Martinez Universal Perineal Interstitial Template) applicator for independent verification of treatment delivery. Measurements were performed in 10 patients, with one to three microMOSFETs per applicator and repeated for one to four fractions, resulting in 50 in vivo measurements. Phantom measurements were used to determine characteristics of the microMOSFETs.ResultsPhantom measurements showed a linear relationship between dose and microMOSFET threshold voltage, and a calibration coefficient (mV/cGy) was determined. Reproducibility of repeated 50 cGy irradiations was 2% (1 standard deviation). Distance and angle dependencies were measured and correction factors were determined. Subsequently, three microMOSFETs were placed in a phantom to measure a validation plan. The difference between predicted and measured dose was less than the measurement uncertainty (±9%, 2 standard deviations). In vivo measurements were corrected for distance and angle dependencies. Differences between predicted and measured dose in the patients were smaller than the measurement uncertainty for the majority of the measurements.ConclusionsIn vivo dosimetry using microMOSFETs in MUPIT and Utrecht Interstitial Fletcher applicators has proved to be feasible. Reimaging should be performed after detection of differences larger than 10% between predicted and measured dose to verify the applicator configuration. Movement of the applicator relative to the target or organs at risk is undetectable with this method.     

Improving muscular endurance with the MVe Fitness Chair™ in breast cancer survivors: A feasibility and efficacy study

ObjectivesTo assess the feasibility and efficacy of delivering Pilates exercises for resistance training to breast cancer survivors using the MVe Fitness Chair?.DesignPilot randomized controlled trial.MethodsTwenty-six female breast cancer survivors were randomized to use the MVe Fitness Chair? (n = 8), traditional resistance training (n = 8), or a control group (no exercise) (CO) (n = 10). The MVe Fitness Chair? and traditional resistance training groups completed 8 weeks of exercise. Muscular endurance was assessed pre and post-test for comparisons within and between groups using push ups, curl ups, and the Dynamic Muscular Endurance Test Battery for Cancer Patients of Various Ages.ResultsFeasibility of the MVe Fitness Chair? was good, evidenced by over 80% adherence for both exercise groups and positive narrative feedback. Significant improvements in muscular endurance were observed in the MVe Fitness Chair? (p < 0.002) and traditional resistance training groups (p < 0.001), but there were no differences in improvement between the MVe Fitness Chair? and traditional resistance training groups (p < 0.711) indicating that Pilates and traditional resistance training may be equally effective at improving muscular endurance in this population.ConclusionsThe MVe Fitness Chair? is feasible for use in breast cancer survivors. It appears to promote similar improvements in muscular endurance when compared to traditional resistance training, but has several advantages over traditional resistance training, including cost, logistics, enjoyment, and ease of learning.