Xerostomia after radiotherapy. What matters--mean total dose or dose to each parotid gland?

PURPOSE

Xerostomia is a debilitating side effect of radiotherapy in patients with head and neck cancer. We undertook a prospective study of the effect on xerostomia and outcomes of sparing one or both parotid glands during radiotherapy for patients with squamous cell carcinoma of the head and neck.

METHODS AND MATERIALS

Patients with locally advanced squamous cell carcinoma of the head and neck received definitive (70 Gy in 2 Gy fractions) or adjuvant (60-66 Gy in 2 Gy fractions) curative-intent radiotherapy using helical tomotherapy with concurrent chemotherapy if appropriate. Group A received < 26 Gy to the left and right parotids and group B received < 26 Gy to either parotid.

RESULTS

The study included 126 patients; 114 (55 in group A and 59 in group B) had follow-up data. There were no statistically significant differences between groups in disease stage. Xerostomia was significantly reduced in group A vs. group B (p = 0.0381). Patients in group A also had significantly less dysphagia. Relapse-free and overall survival were not compromised in group A: 2-year relapse-free survival was 86% vs. 72% in group B (p = 0.361); 2-year overall survival was 88% and 76%, respectively (p = 0.251).

CONCLUSION

This analysis suggests that reducing radiotherapy doses to both parotid glands to < 26 Gy can reduce xerostomia and dysphagia significantly without compromising survival. Sparing both parotids while maintaining target volume coverage and clinical outcome should be the treatment goal and reporting radiotherapy doses delivered to the individual parotids should be standard practice.

Radiation dose reduction in CT of the brain: can advanced noise filtering compensate for loss of image quality?

BACKGROUND

Computed tomography (CT) of the brain is performed with high local doses due to high demands on low contrast resolution. Advanced algorithms for noise reduction might be able to preserve critical image information when reducing radiation dose.

PURPOSE

To evaluate the effect of advanced noise filtering on image quality in brain CT acquired with reduced radiation dose.

MATERIAL AND METHODS

Thirty patients referred for non-enhanced CT of the brain were examined with two helical protocols: normal dose (ND, CTDI(vol) 57 mGy) and low dose (LD, CTDI(vol) 40 mGy) implying a 30% radiation dose reduction. Images from the LD examinations were also postprocessed with a noise reduction software with non-linear filters (SharpView CT), creating filtered low dose images (FLD) for each patient. The three image stacks for each patient were presented side by side in randomized order. Five radiologists, blinded for dose level and filtering, ranked these three axial image stacks (ND, LD, FLD) as best to poorest (1 to 3) regarding three image quality criteria. Measurements of mean Hounsfield units (HU) and standard deviation (SD) of the HU were calculated for large region of interest in the centrum semiovale as a measure for noise.

RESULTS

Ranking results in pooled data showed that the advanced noise filtering significantly improved the image quality in FLD as compared to LD images for all tested criteria. No significant differences in image quality were found between ND examinations and FLD. However, there was a notable inter-reader spread of the ranking. SD values were 15% higher for LD as compared to ND and FLD.

CONCLUSION

The advanced noise filtering clearly improves image quality of CT examinations of the brain. This effect can be used to significantly lower radiation dose.

Biliary atresia: lessons learned from the voluntary German registry

INTRODUCTION

Aim of the study was to carry out a 5-year survey of German patients with biliary atresia (BA) and to launch a discussion regarding the feasibility of voluntary registries in unregulated healthcare systems.

METHODS

A retrospective analysis of German BA patients born between 2001 and 2005, based on data collected from the voluntary European Biliary Atresia Registry (EBAR), was carried out and supplemented by data from all BA patients who underwent liver transplantation at the only 4 pediatric transplantation centers (pLTx) in Germany which are so far not registered at EBAR. Survival rates were calculated using Kaplan-Meier analysis and compared by Cox regression to determine the predictive value of age at surgery and the influence of the center size (fewer or more than 5 patients/study period) on overall survival and survival with native liver.

RESULTS

A critical review of the 148 German EBAR charts revealed that 11 patients (7.4%) had no biliary atresia. The remaining 137 patients from EBAR together with 46 BA patients who underwent LTx without prior registration at EBAR were evaluated with a median follow-up of 39 months (range: 25-85 months). 29 hospitals performed a total of 159 Kasai procedures, but only 7 centers treated 5 or more patients (116 patients, range: 5-68), and 22 hospitals performed less than 5 KP (43 patients, range: 1-4). Primary LTx was performed in 21 patients (11.5%) and 3 patients died without surgical intervention. 16 patients were lost to follow-up (8.7%). Overall survival after 2 years was 83.3% (139 patients), including 105 patients (63%) who had undergone LTx and 34 patients (20.3%) with native liver. 28 patients died (16.7%), 8 after LTx (5.8%). The experience of the center was the only factor with a significant predictive value for jaundice-free survival with native liver (p=0.001).

CONCLUSION

25% of all German BA patients were not registered at EBAR, and 29 clinics were involved in the surgical management of BA patients. Therefore a new approach consisting of an internet-based decentralized registry for rare neonatal liver diseases is outlined which could improve the future management of patients with BA. The centralization of such patients at experienced centers with higher caseloads is necessary in Germany and would improve the outcome of patients with biliary atresia.

[Radiation therapy in head and neck cancer. Highlights from ASCO 2010]

In contrast to conventional radiotherapy, intensity modulated radiotherapy (IMRT) enables individually adjusted dose and intensity depending on tumor size and organs at risk, thus enabling radiotherapy of complex volumes in the head and neck area using high doses. Despite new data presented at the annual congress of the American Society of Clinical Oncology (ASCO), questions remain unanswered in two basic categories: (a) How do we use IMRT with other important advances in head and neck cancer treatment, such as altered fractionation, chemotherapy, and novel agents? (b) Does IMRT in its current form produce sufficient risk:benefit improvements in salivary gland sparing/less xerostomia, better targeting/local control and less late toxicity? Whether IMRT with its complex target volume definition and dose distribution leads to improved local control needs to be further investigated in relevant studies.

Human papilloma virus in locally advanced stage III/IV squamous cell cancer of the oropharynx and impact on choice of therapy

Oropharyngeal cancers (OPCs) are now believed to arise from two distinct pathways: one influenced by alcohol and tobacco use and the other a result of genomic instability induced by the human papilloma virus (HPV). The incidence of HPV-associated OPC is increasing, particularly among younger males. Case series and clinical trials suggest that patients with HPV-positive OPC have better clinical outcomes than those with HPV-negative tumors. We evaluated efficacy data in published articles and meeting abstracts from clinical studies comparing response rates and survival outcomes in patients with HPV-positive and -negative locally advanced OPC. Eight clinical studies were identified: half were prospective analyses of outcome according to HPV status; the remaining four reports were retrospective analyses. The majority of these analyses showed that patients with HPV-positive tumors had significantly better responses to treatment than those with HPV-negative tumors. In the two studies in which the effect of treatment was also evaluated, patients with HPV-positive tumors did not benefit significantly from intensive therapy, unlike those with HPV-negative tumors. HPV-positive tumor status is an important prognostic factor associated with a favorable outcome in patients with locally advanced OPC. The HPV status of patients with locally advanced OPC should be established before treatment commences. Surgery is well accepted in the treatment of OPC, but the place of chemoradiotherapy has yet to be confirmed. Prospective, well-controlled clinical studies are required to establish whether chemoradiotherapy provides an acceptable risk-benefit balance versus high-quality radiotherapy alone in patients with HPV-positive OPC, in whom the goal is to maximize progression-free and overall survival, while preserving function and maintaining quality of life.

Preconceptional oral vaccination prevents experimental biliary atresia in newborn mice

INTRODUCTION

Biliary atresia (BA) in humans resembles BA induced in Balb/c-mice by Rhesus Rotavirus (RRV). In mice, susceptibility to BA is ascribed to the lack of maternally derived immune protection. This study investigated whether vaccination of dams against RRV protected their offspring from developing BA.

MATERIALS AND METHODS

Before mating, female mice were vaccinated orally with RotaTeq or Rotarix. Pups (n=243) from both test groups and a control group were intraperitoneally infected with RRV. Sacrifice of the animals was scheduled for days 7, 14 and 21 after infection. Then, gross and mircoscopia findings of the liver and the hepatoduodenal ligament gave evidence of BA, and hepatic viral load was tested by virus-specific real-time PCR, as well as plaque forming units.

RESULTS

Two weeks after infection, the incidence of cholestasis was 100% in controls, 77% in pups of RotaTeq-vaccinated dams, and 56% in pups of Rotarix-vaccinated dams. However, in contrast to controls (incidence of BA: 82%) most pups in the test groups recovered (incidence of BA in pups of RotaTeq-vaccinated dams 11%; incidence of BA in pups of Rotarix-vaccinated dams 3%). Hepatic viral load was identical at various time-points in all pups, suggesting that differences in RRV clearance did not underlie this effect.

CONCLUSION

In this mouse model, oral vaccination with RotaTeq and Rotarix prevented most RRV-induced BA. This provides a new approach to a better understanding of both the pathomechanism of BA development and the capabilities of the innate immune system. It also suggests a first approach for prophylaxis against BA.