Dose development in sinonasal imaging over the last decade - a retrospective patient study.

BACKGROUND: Computed tomography (CT) has become the primary imaging modality for visualization of the paranasal sinuses. In this retrospective, single center patient study the radiation dose development in the past 12 years in CT imaging of the paranasal sinuses was assessed. METHODS: The computed tomography dose index (CTDIVol) and dose length product (DLP) of a total of 1246 patients (average age: 41 ± 18 years, 361 females, 885 males) were evaluated, who received imaging of the paranasal sinuses either for chronic sinusitis diagnostic, preoperatively or posttraumatically. Scans were performed on three different CT scanners (Somatom Definition AS, Somatom Definition AS+, Somatom Force, all from Siemens Healthineers) and on one CBCT (Morita) ranging from 2010 to 2022. Reconstruction techniques were filtered back projection and three generations of iterative reconstruction (IRIS, SAFIRE, ADMIRE, all from Siemens Healthineers). Group comparisons were performed using either parametrical (ANOVA) or non-parametrical tests (Kruskal-Wallis Test), where applicable. RESULTS: Over the past 12 years, there was a 73%, 54%, and 66% CTDIVol reduction and a significant (p < 0.001) 72%, 33%, and 67% DLP reduction in assessing the paranasal sinuses for chronic sinusitis, preoperatively and posttraumatically, respectively. CONCLUSION: Technological developments in CT imaging, both hardware and software based, have led to a significant reduction in dose exposure in recent years. Particularly in imaging of the paranasal sinuses, the reduction of radiation exposure is of great interest due to the often young patient age and radiation-sensitive organs in the area of radiation exposure.

Tin filter compared to low kV protocols - optimizing sinonasal imaging in computed tomography.

OBJECTIVES: Paranasal sinus imaging due to chronic inflammatory disease is one of the most common examinations in head and neck radiology with CT imaging considered the current gold standard. In this phantom study we analyzed different low dose CT protocols in terms of image quality, radiation exposure and subjective evaluation in order to establish an optimized scanning protocol. METHODS: In a phantom study, an Alderson phantom was scanned using 12 protocols between 70-120 kV and 25-200 mAs with and without tin filtration. For all datasets, iterative reconstruction was used. Data were objectively evaluated (image noise, (dose-weighted) contrast-to-noise ratio) and for subjective evaluation an online survey using a Likert scale was performed to reach a large group of clinically experienced reader (n = 62). The protocol was considered diagnostically insufficient if the median score was 4 and above and if more than 10% of raters scored 4 and above on the Likert scale. For an interreader agreement an ICC was calculated. To compare clinical value in relation to the applied dose and the objective image parameters, we calculated a figure of merit (FOM) and ranked the protocols accordingly. RESULTS: There was an overall moderate agreement between the 62 readers for the 12 examined CT protocols. In this phantom study, protocols with 100 kV with spectral shaping and 50-100 mAs obtained the best results for its combination of dose, image quality and clinical information value for diagnosing sinusitis (FOM 1st- 2nd place) with the 70 kV and 50 mAs as a good alternative as well (Sinusitis: FOM shared 2nd). For preoperative planning, where a higher dose is necessary, 100 kV with spectral shaping and 100 mAs achieved the overall best results (FOM 1st place) with 70 kV and 50 mAs ranking 4th. CONCLUSION: 100-kV protocols with spectral shaping or low kV protocols (70 kV) with a similarly low dose showed the best figure of merit for imaging sinonasal disease and preoperative planning. With modern scanner technology available, spectral shaping or low KV protocols should be used for sinusitis imaging.

One-stage reconstruction of the entire upper lip and the columella with a modified bilateral nasolabial flap.

The functional and cosmetic reconstruction of the upper lip after a subtotal defect is a highly demanding challenge, especially when the columella is involved. In the majority of cases, the surgical techniques described in the literature are suitable only for restoring the function and appearance of the upper lip but not for reconstructing adjacent areas. In this article, we present the case of an 85-year-old female patient with an extensive, aggressive and highly invasive basal cell carcinoma of the upper lip and the columella. We describe a modification of the nasolabial flap technique using cheek tissue for the reconstruction of the defect. The modified flap is used for both the full-thickness reconstruction of the subtotal upper-lip defect and the restoration of the function and appearance of the columella. This technique allows excellent cosmetic and functional results to be obtained in a single-stage procedure.

Photodynamic therapy with meta-tetrahydroxyphenylchlorin (Foscan) in the management of squamous cell carcinoma of the head and neck: experience with 35 patients.

Photodynamic therapy (PDT) is a relatively new method of treating superficial tumours of the skin and mucosa. After the injection of a photosensitizing agent, the tumour area is exposed to non-thermal laser light. This causes a phototoxic reaction, producing oxygen radicals that destroy tumour cells. From November 2003 to July 2007, a total of 35 patients with recurrent squamous cell carcinoma or secondary tumours of the head and neck region were treated with PDT at the German Armed Forces Hospital in Ulm. These patients had failed or found unsuitable for other treatments. Meta-tetrahydroxyphenylchlorin (mTHPC), known under the trade name of Foscan, was used as the photosensitizing agent. Local control was achieved in 21 patients (60%) and partial remission in 10 patients (28.5%). Four patients (11.5%) did not respond to PDT treatment. The mean duration of overall survival was 401.45 (+/-321.2) days, median was 356 after the completion of treatment. The mean duration of recurrence-free survival was 327.7 (+/-131.1) days, median was 181 for patients with complete remission. None of the patient developed serious complications. Photodynamic therapy is an important treatment option for patients who present with recurrent carcinoma or secondary tumours of the upper aerodigestive tract and who have failed or unsuitable for other treatments. Due to the excellent treatment results that have been achieved so far, PDT may in the future also play a role in the primary treatment of superficial tumours of the oral cavity, pharynx and larynx.