4 p

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12

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48

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25 px

42 p

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S1S2S3S4S5S6S7S8S9S10S11S12

1 px = 2.39 mm

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PATIENT SPECIFIC DEPOSITION ENHANCEMENT OF NASAL SPRAYS

IN CT-DERIVED HUMAN NASAL REPLICAS LT Holbrook1, A Burke1, S Basu2, E

Monaghan1, J Kimbell2, and WD Bennett1. Center for Environmental Medicine, Asthma, and Lung Biology1.

Department of Otolaryngology/Head & Neck Surgery2. University of North Carolina, Chapel Hill, NC, USA.

Introduction

Individuals who suffer from chronic rinosinusitis (CRS) may undergo functional endoscopic sinus surgery (FESS) if nasal sprays do not alleviate their symptoms. Nasal sprays are used to manage this condition before and after surgery. This study aims to analyze how well a nasal spray penetrates into the nasal pathways using the current administration instructions and a bottle orientation determined using line-of-sight within each subject’s nasal passage. A new metric of spray area (SA) is developed and compared to the penetration depth. An improvement in performance of the spray could result in improved effectiveness of treatments with the goal of decreasing the need for FESS.

Study Design and Methods

• Nasal spray was administered at a depth of 5 mm with a forward head tilt of 22.5°.• Steady inspiratory air flow rate was determined by the subjects’ weights.• The nasal spray was labeled with Tc99m and images were taken using a 2D gamma camera.• Images were processed in ImageJ (Schneider et al., 2012) by constructing a region of interest (ROI) referenced to fixed Americium

sources on the model.• The projected area coated by the nasal spray was defined as being cells with greater than three times the background activity, and

normalized to the total possible spray area determined by a flood of the model. • LOS scores were determined qualitatively by inspection within the numerical modeling space.

Supported by NIH HL122154

Discussion and Conclusions

• The line-of-sight method leads to better penetration to

the posterior nasal cavity and greater percent coverage of

internal nasal tissue.

• Drug delivered by nasal spray is not reaching the maxillary

sinus, therefore minimizing its effectiveness in this region

• The nozzle positioning tool likely has a large impact on the

variance in results

• Greater line-of-sight score leads to greater improvement

from CU to LOS deposition

1.) Schneider, C. A.; Rasband, W. S. & Eliceiri, K. W. (2012), "NIH Image to ImageJ: 25 years of image analysis", Nature methods 9(7): 671-675, PMID 22930834

Model Development

Sinus CT scans of patients before and after FESS were digitally reconstructed and used to print rigid 3D models of the entire nasal cavity. The cavity posterior to the internal nasal valve was printed with rigid material, while the area anterior to the nasal valve was printed with soft, flexible material. A nozzle-positioning tool was printed for a current use (CU) case and line-of-sight (LOS) case for each model.

Results

Nasacort deposition results in the Pre- and Post-FESS models showed that the fraction of drug sprayed in the nostril depositing posterior to the nasal valve was increased with the line-of-sight method, and Post-FESS. For both models 50-60% of deposition remains in the anterior nares.

No deposition occurred > 86 mm into the nasal model or in the maxillary sinuses.

<0.10%0.10-0.20%0.20-0.30%0.30-0.40%0.40-0.50%0.50-0.60%0.60-0.70%0.70-0.80%0.80-0.90%>0.90%

Model Left/Right CU LOS

SD04 Pre Right 27.87% 40.71%Left 17.28% 22.89%

SD05 Pre Right 32.14% 45.60%Left 32.22% 34.23%

SD05 Post Left 24.01% 34.07%

Model Left/Right LOS Score

SD04 Pre Right 2Left 1

SD05 Pre Right 4Left 3

SD05 Post Left >0

Gamma scintigraphy image of two scans of SD05 Pre without the soft nose attached, CU left and LOS right, with ROI overlaid. Pixels colored by percent deposition within each pixel. Percent deposition is defined as a fraction of the entire spray, including what deposited within the soft nose.

Line-of-sight Scores (4=Best LOS)

Spray Area as Percentage of Total Possible Surface Area

A * Indicates a significant difference in values as determined by t test, with a value of p=0.05 indicating significance.

*

*

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Intramodel CU vs LOS Deposition in Left Nostril of SD05 Pre

*

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Intermodel Deposition Comparison of CU Method in SD04 Pre and SD05 Pre

**

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Intramodel CU vs LOS Deposition in Left Nostril of SD05 Post

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*

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Intermodel Deposition Comparison of CU Method Pre and Post FESS in SD05