Vocal-cord Only vs. Complete Laryngeal radiation (VOCAL): a randomized multicentric Bayesian phase II trial

BACKGROUND

Radiotherapy, along with laser surgery, is considered a standard treatment option for patients with early glottic squamous cell cancer (SCC). Historically, patients have received complete larynx radiotherapy (CL-RT) due to fear of swallowing and respiratory laryngeal motion and this remains the standard approach in many academic institutions. Local control (LC) rates with CL-RT have been excellent, however this treatment can carry significant toxicities include adverse voice and swallowing outcomes, along with increased long-term risk of cerebrovascular morbidity. A recent retrospective study reported improved voice quality and similar local control outcomes with focused vocal cord radiotherapy (VC-RT) compared to CL-RT. There is currently no prospective evidence on the safety of VC-RT. The primary objective of this Bayesian Phase II trial is to compare the LC of VC-RT to that of CL-RT in patients with T1N0 glottic SCC.

METHODS

One hundred and fifty-five patients with T1a-b N0 SCC of the true vocal cords that are n ot candidate or declined laser surgery, will be randomized in a 1:3 ratio the control arm (CL-RT) and the experimental arm (VC-RT). Randomisation will be stratified by tumor stage (T1a/T1b) and by site (each site will be allowed to select one preferred radiation dose regimen, to be used in both arms). CL-RT volumes will correspond to the conventional RT volumes, with the planning target volume extending from the top of thyroid cartilage lamina superiorly to the bottom of the cricoid inferiorly. VC-RT volumes will include the involved vocal cord(s) and a margin accounting for respiration and set-up uncertainty. The primary endpoint will be LC at 2-years, while secondary endpoints will include patient-reported outcomes (voice impairment, dysphagia and symptom burden), acute and late toxicity radiation-induced toxicity, overall survival, progression free survival, as well as an optional component of acoustic and objective measures of voice analysis using the Consensus Auditory-Perceptual Evaluation of Voice.

DISCUSSION

This study would constitute the first prospective evidence on the efficacy and safety of VC-RT in early glottic cancer. If positive, this study would result in the adoption of VC-RT as standard approach in early glottic cancer.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03759431 Registration date: November 30, 2018.

Evaluation of the accuracy of deformable image registration on MRI with a physical phantom

Background and purpose

Magnetic resonance imaging (MRI) has gained popularity in radiation therapy simulation because it provides superior soft tissue contrast, which facilitates more accurate target delineation compared with computed tomography (CT) and does not expose the patient to ionizing radiation. However, image registration errors in commercial software have not been widely reported. Here we evaluated the accuracy of deformable image registration (DIR) by using a physical phantom for MRI.

Methods and materials

We used the “Wuphantom” for end‐to‐end testing of DIR accuracy for MRI. This acrylic phantom is filled with water and includes several fillable inserts to simulate various tissue shapes and properties. Deformations and changes in anatomic locations are simulated by changing the rotations of the phantom and inserts. We used Varian Velocity DIR software (v4.0) and CT (head and neck protocol) and MR (T1‐ and T2‐weighted head protocol) images to test DIR accuracy between image modalities (MRI vs CT) and within the same image modality (MRI vs MRI) in 11 rotation deformation scenarios. Large inserts filled with Mobil DTE oil were used to simulate fatty tissue, and small inserts filled with agarose gel were used to simulate tissues slightly denser than water (e.g., prostate). Contours of all inserts were generated before DIR to provide a baseline for contour size and shape. DIR was done with the MR Correctable Deformable DIR method, and all deformed contours were compared with the original contours. The Dice similarity coefficient (DSC) and mean distance to agreement (MDA) were used to quantitatively validate DIR accuracy. We also used large and small regions of interest (ROIs) during between‐modality DIR tests to simulate validation of DIR accuracy for organs at risk (OARs) and propagation of individual clinical target volume (CTV) contours.

Results

No significant differences in DIR accuracy were found for T1:T1 and T2:T2 comparisons (P > 0.05). DIR was less accurate for between‐modality comparisons than for same‐modality comparisons, and was less accurate for T1 vs CT than for T2 vs CT (P < 0.001). For between‐modality comparisons, use of a small ROI improved DIR accuracy for both T1 and T2 images.

Conclusion

The simple design of the Wuphantom allows seamless testing of DIR; here we validated the accuracy of MRI DIR in end‐to‐end testing. T2 images had superior DIR accuracy compared with T1 images. Use of small ROIs improves DIR accuracy for target contour propagation.

Dosimetric and Radiobiological Evaluation of Patient Setup Accuracy in Head-and-neck Radiotherapy Using Daily Computed Tomography-on-rails-based Corrections

Introduction:

This study evaluates treatment plans aiming at determining the expected impact of daily patient setup corrections on the delivered dose distribution and plan parameters in head-and-neck radiotherapy.

Materials and Methods:

In this study, 10 head-and-neck cancer patients are evaluated. For the evaluation of daily changes of the patient internal anatomy, image-guided radiation therapy based on computed tomography (CT)-on-rails was used. The daily-acquired CT-on-rails images were deformedly registered to the CT scan that was used during treatment planning. Two approaches were used during data analysis (“cascade” and “one-to-all”). The dosimetric and radiobiological differences of the dose distributions with and without patient setup correction were calculated. The evaluation is performed using dose–volume histograms; the biologically effective uniform dose () and the complication-free tumor control probability (P₊) were also calculated. The dose–response curves of each target and organ at risk (OAR), as well as the corresponding P₊ curves, were calculated.

Results:

The average difference for the “one-to-all” case is 0.6 ± 1.8 Gy and for the “cascade” case is 0.5 ± 1.8 Gy. The value of P₊ was lowest for the cascade case (in 80% of the patients).

Discussion:

Overall, the lowest P_I is observed in the one-to-all cases. Dosimetrically, CT-on-rails data are not worse or better than the planned data.

Conclusions:

The differences between the evaluated “one-to-all” and “cascade” dose distributions were small. Although the differences of those doses against the “planned” dose distributions were small for the majority of the patients, they were large for given patients at risk and OAR.

Morphine blood levels, dependence, and regulation of hippocampal subgranular zone proliferation rely on administration paradigm

Chronic morphine, administered via s.c. pellet, decreases the number of proliferating cells in the dentate gyrus subgranular zone (SGZ) in both rats and mice. This robust morphine-induced decrease could be used to better understand mechanisms regulating adult hippocampal neurogenesis, as well as to explore the relationship between neurogenesis and drug dependence, withdrawal, and relapse behaviors. Such research would benefit enormously from identifying a route of morphine administration that produces addiction-relevant blood levels of morphine, results in a high degree of dependence, translates to both rat and mouse, and is free of the behavioral confounds of s.c. pellets. Therefore, we examined a classic chronic morphine pellet paradigm (two s.c. pellets over 5 days) versus three chronic morphine injection paradigms (escalating dose i.p. injections over 2, 5, or 10 days) for their effect in adult male C57BL/6J mice. We assessed blood morphine levels, SGZ proliferation, and drug dependence as assessed by tolerance to locomotion sensitization and naloxone-precipitated withdrawal. The pellet paradigm produced high and relatively stable blood levels of morphine, a high degree of dependence, and a significant decrease in SGZ proliferation. In contrast, the three injection paradigms produced transient spikes in morphine blood levels, significantly less dependence than the pellet paradigm, and no significant decrease in SGZ proliferation. These data show that regulation of mouse SGZ proliferation requires high and relatively stable blood levels of morphine, and provide critical knowledge for the design of future studies to probe the relationship between addiction and neurogenesis.

Occupationally related hydrogen sulfide deaths in the United States from 1984 to 1994

Alice Hamilton described fatal work injuries from acute hydrogen sulfide poisonings in 1925 in her book Industrial Poisons in the United States. There is no unique code for H2S poisoning in the International Classification of Diseases, 9th Revision; therefore, these deaths cannot be identified easily from vital records. We reviewed US Occupational Safety and Health Administration (OSHA) investigation records for the period 1984 to 1994 for mention of hazardous substance 1480 (hydrogen sulfide). There were 80 fatalities from hydrogen sulfide in 57 incidents, with 19 fatalities and 36 injuries among coworkers attempting to rescue fallen workers. Only 17% of the deaths were at workplaces covered by collective bargaining agreements. OSHA issued citations for violation of respiratory protection and confined space standards in 60% of the fatalities. The use of hydrogen sulfide detection equipment, air-supplied respirators, and confined space safety training would have prevented most of the fatalities.

A statistical approach to the prediction of verifiable heroin use from total codeine and total morphine concentrations in urine

There has been much debate in urine drug testing over what criteria should be applied to total codeine and total morphine concentration data to determine the likelihood that a urine donor has used heroin and whether such use can be demonstrated by the presence of 6-acetylmorphine. After determining that the stability of 6-acetylmorphine in frozen urine is adequate for a period of at least two years, a database of over 100 codeine and/or morphine positive urine specimens was subjected to relative operating characteristic analysis to identify a criterion that would indicate a high probability of detecting 6-acetylmorphine in a specimen and thus confirming heroin use. A two-fold criterion was identified. By using a criterion that requires the total morphine concentration to be greater than 5.000 mg/L and the total codeine to total morphine ratio to be less than 0.125, one can predict the presence of 6-acetylmorphine with a sensitivity of 92%, a specificity of 79%, and an overall accuracy of 73%. Although this criterion is statistically the most accurate in terms of both sensitivity and specificity for the data analyzed by the author, the results of other, criteria are presented to aid toxicologists and medical review officers in determining if analysis for 6-acetylmorphine is likely to produce useful results.

A survey of the incidence of Salmonella species and Enterobacteriaceae in poultry feeds and feed components

Between July 1990 and April 1991 the rate of contamination with Salmonella species of poultry feeds and feed components used by the Dutch feed industry was surveyed. Ten per cent of 360, 10 g samples of poultry feeds were found to be contaminated. Mash feeds, mostly used for layer-breeders, were far more frequently (21 per cent) contaminated than pelleted feeds (1.4 per cent). The rate of contamination of 130 samples of fish meal was 31 per cent, of 83 samples of meat and bone meal 4 per cent, 58 samples of tapioca 2 per cent and of 15 samples of maize grits 27 per cent. Twenty-eight serotypes of salmonellae were isolated, but no Salmonella enteritidis was found, despite the occurrence of an epidemic in poultry caused by this serotype since 1987. The serotypes isolated most frequently were not the same as those encountered in poultry flocks. The Enterobacteriaceae isolated from the feedstuffs were predominantly thermotrophic. They were shown to be useful markers of the rate of contamination with salmonellae and of the efficiency of decontamination of the feedstuffs by pelletisation.

A simplified procedure for the determination of free codeine, free morphine, and 6-acetylmorphine in urine

A procedure for detection and quantification of free codeine, free morphine, and 6-acetylmorphine in urine is presented. The analytes were extracted at neutral pH by solid-phase extraction prior to derivatization to their trifluoroacetyl derivatives. The derivatized extracts were analyzed by gas chromatography/mass spectrometry in the electron impact mode. Confirmation of the analytes was accomplished by comparing the ion abundance ratios of the analytes to those of a previously analyzed standard. The qualitative ion abundance ratios were required to be within 20% of those of the standard for acceptance. Quantification was based on the tri-deuterated analogs of the analytes. Linearity was obtained in the range of 10 to 1000 ng/mL, with correlation coefficients of all analytes exceeding 0.999. Percent recoveries were 90% for codeine, 88% for morphine, and 85% for 6-acetylmorphine. No hydrolysis of 6-acetylmorphine occurs during the extraction procedure. The authors also studied the stability of 6-acetylmorphine at various storage conditions of pH, temperature, and chemical preservation. 6-Acetylmorphine was found to be stable for 12 weeks when stored at -17 degrees C.

A simplified procedure for the isolation, characterization, and identification of weak acid and neutral drugs from whole blood

The presented method utilizes commercially available Chem Elut columns for the extraction of weak acid and neutral drugs. The residue from this extraction is purified by partitioning between hexane and acetonitrile. The drugs are analyzed using a gas chromatograph equipped with a 0.53-mm i.d. dimethyl silicone capillary column, a packed column inlet adapter, and a flame ionization detector. The drugs are characterized by their retention index. The procedure is rapid, and clean chromatograms are the rule with essentially no lipid interference for flame ionization or mass spectrometer detection systems. The retention index has proven to be a very reliable parameter for describing chromatographic behavior. For probarbital, the internal standard, the calculated retention index averaged 1529.70 with a standard deviation of 1.27 index units (n = 115).

Hydatid disease in Ethiopia: clinical survey with some immunodiagnostic test results

After surveying various regions of Ethiopia using clinical examinations, filter paper indirect hemagglutination (IHA) test, and hydatid skin test, a hyperendemic focus of hydatid disease (Echinococcus granulosus) was found in southwestern Ethiopia. Two tribes, the Dassanetch and Nyangatom, in the lower Omo River Valley were found to have a particularly high prevalence of the disease. Of 1,342 individuals from these two tribes 4.8% had palpable abdominal cysts and 15% had hepatomegaly. This contrasts with 0.2% and 5.6%, respectively, for all other groups combined. Among the Dassanetch and Nyangatom, 6.4% had filter paper indirect hemagglutination titers 1:128 or greater versus only 0.3% for the combined results of other tested Ethiopian groups. Of 366 Dassanetch and Nyangatom, 31.7% were positive by the hydatid skin test versus 5.9% for all other southwestern Ethiopian tribes tested. Marked sex differences in hydatid skin test positivity, not reflected in the clinical findings or the IHA results, limit the use of this test for hydatid disease and suggest that possibility that men be exposed more frequently than women to other antigens cross-reacting with the hydatid skin test antigen.