Clinical Outcomes of Image-Guided Volumetric Modulated Arc Therapy for Total Body Irradiation

PURPOSE/OBJECTIVE(S)

Volumetric modulated arc therapy (VMAT)-based total body irradiation (TBI) with image guidance is a novel technique that is increasing in implementation. Compared to conventional TBI, VMAT-TBI offers favorable dose homogeneity, better organ-at-risk sparing, and enhanced patient comfort. However, whether these dosimetric advantages translate to improved clinical outcomes that justify the increased planning and delivery burden is not well understood. Only a single study of clinical outcomes of VMAT-TBI exists in the literature. We present the largest study to date of clinical outcomes of VMAT-TBI.

MATERIALS/METHODS

In this IRB-approved retrospective single-institution study, all patients treated with VMAT-TBI conditioning for allogeneic stem cell transplant, per the institution's published protocol, were identified. Dosimetric data were abstracted from the radiation oncology treatment planning system. Clinical data were abstracted from the electronic medical record. The primary outcome was six-month overall survival (6M OS) from the last day of TBI by Kaplan-Meier method.

RESULTS

Fifty-five patients (47 adult and 8 pediatric) were treated with VMAT-TBI between June 2020 and December 2022. All patients received conditioning chemotherapy with standard-dose TBI of 12 or 13.2 Gy in 8 twice-daily fractions. The PTV coverage (V95%) mean was 95.3% ± 1.2%. Mean lung dose was 9.5 Gy ± 0.6 for adult patients and 8.4 Gy ± 0.9 for pediatric patients. Mean lung dose rate was 18.0 cGy/min ± 4.4. Mean kidney dose was 5.9 Gy ± 0.6. Mean skin dose measured by MOSFET was 12.7 Gy ± 1.2. Median treatment time was 63 minutes (range: 53-104). Median follow-up was 7.7 months. At most recent follow-up, 78% of patients were alive. 6M OS was 82%. Common acute toxicities were fatigue (90.9% of patients, all grade 1-2), diarrhea (70.9%, all grade 1-2), nausea (76.4%, all grade 1-2), mucositis (60% grade 1-2, 12.7% grade 3, 1.8% grade 4, no grade 5), and xerostomia (54.5%, all grade 1). Mean pretreatment FEV1 was 98.3 percent of predicted (%p) ± 11.9%p and mean posttreatment FEV1 was 94.7%p ± 13.8%p. Mean pretreatment GFR was 101.4mL/min/1.73m² ± 17.4, mean 3-month posttreatment GFR was 92.4 ± 20.0, and mean 6-month posttreatment GFR was 97.5 ± 26.48. One patient experienced grade 2 pneumonitis; there were no other cases of pneumonitis. There were no acute grade 3+ toxicities aside from mucositis. Observed late toxicities were cataracts (7.3%, all grades 1-3) and hypothyroidism (12.7%, all grades 1-2). There were no grade 3+ late toxicities. Mild acute graft-versus-host disease (GVHD) was noted in 27.2% of patients and mild chronic GVHD was noted in 14.5% of patients, with no other cases of GVHD.

CONCLUSION

In the largest series to date, VMAT-TBI had excellent oncologic and toxicity outcomes. A randomized trial of VMAT-TBI versus standard TBI is warranted.

Frameless Fractionated Stereotactic Radiosurgery for Brain Metastases: An Institutional Series of 145 Cases

PURPOSE/OBJECTIVE(S)

Cobalt-60 stereotactic radiosurgery (SRS) typically involves single fraction treatment with frame immobilization. However, large tumor size, proximity to critical structures, and prior radiation treatment sometimes necessitate fractionated SRS with mask immobilization. We present a large institutional experience with fractionated mask-based SRS for brain metastases.

MATERIALS/METHODS

In this single-institution, IRB-approved study, all patients treated with mask-based fractionated SRS for brain metastases from March 2017 to January 2023 were identified. The primary outcomes were 1- and 2-year local control (LC) by Kaplan-Meier method.

RESULTS

A total of 118 patients with a total of 145 metastases were treated. The median follow-up time was seven months. The median age at treatment was 64.1 years (range: 26-95 years). 55.9% of patients were female. The most common primary tumors were breast (25.5%), non-small cell lung (23.4%), small-cell lung (8.3%), and melanoma (8.3%). For most cases (59.3%), the indication for fractionation was retreatment. Large size (28.3%), critical location (9.7%), and medical comorbidity (2.1%) were other indications. For all cases, the mean maximal linear size was 34.9 mm and mean target volume was 15.6 cc. For cases fractionated due to size, the mean size was 43.9 mm and mean target volume was 23.8 cc. Median total dose was 2,700 cGy (range: 1,620-3,000), and median dose per fraction (fx) was 600 cGy (range: 405-900). The most common prescriptions were 3,000 cGy/5 fx (40.0% of patients) and 2500 cGy in 500 cGy per fraction (37.2% of patients). Mean maximum dose was 4,833 cGy (range: 2,920-7,500). For 75.2% of treatments, the prescription isodose line was 50 to 59% (mean, 56.9%). Target coverage was 100% in all but one case (99%). For lesions near the brainstem, mean brainstem maximum point dose (MPD) was 9.3 Gy ± 9.8 Gy and brainstem mean dose was 3.3 Gy ± 3.3 Gy. For lesions near the optic pathway, mean optic nerve MPD was 14.4 Gy ± 9.2, optic nerve mean dose was 6.4 Gy ± 5.4 Gy, mean optic chiasm MPD was 11.7 Gy ± 7.9 Gy, and optic chiasm mean dose was 5.4 Gy ± 4.7 Gy. 1-year LC was 88.2% and 2-year LC was 80.4%. When retreatments were excluded, 1-year LC was 98.0% and 2-year LC was 98.0%. 18% of patients had acute grade 1-2 toxicities (fatigue, headache, nausea, and/or alopecia), and one patient had acute grade 3 fatigue. There was no other grade 3+ acute toxicities. 14% of patients had grade 1-2 radiation necrosis (RN); there were no cases of grade 3+ RN.

CONCLUSION

Cobalt-60 frameless fractionated SRS for brain metastases offers excellent local control, rigorous sparing of critical structures, and minimal toxicity. Frameless fractionated SRS should be considered for large, retreated, or critically located metastases.

Radio-Immune Response of Spatially Fractionated Radiotherapy for VMAT Lattice Plans

PURPOSE/OBJECTIVE(S)

To evaluate radio-immune response of spatially fractionated radiotherapy (SFRT) for large tumors using VMAT Lattice technique in terms of tumor volume under irradiation and dose fractionation schemes after SFRT.

MATERIALS/METHODS

Eleven patients treated with SFRT from a single institution were retrospectively replanned to deliver 15Gy in single fraction using Lattice technique. High dose regions are defined by multiple spheres with the diameter of 1.25 to 1.5cm and their vertex space of 3.0 to 4.0cm inside of GTV. VMAT plans with multiple arcs were developed for SFRT. Four palliative fractionation regimens of 200cGy x 12 (EQD2 = 24Gy with a/b of 10Gy), 400cGy x 5 (23.3Gy), 600cGy x 3 (24Gy) and 800cGy x2 (24Gy) and four definitive regimens of 200cGy x 24 (EQD2 = 48Gy), 400cGy x 10 (46.7Gy), 600cGy x 6 (48Gy) and 800cGy x 4 (48Gy) were considered for radiotherapy to follow SFRT. Linear quadratic (LQ) model is compared with radio-immune (RI) response model in which the activation of cytotoxic T lymphocytes, tumor immune suppression capability and immunotherapy drugs can be considered. Tumor regrowth time (TRT, time to tumor regrowth to the original volume after treatment) from each model was compared as a measure of benefit achieved from the application of SFRT.

RESULTS

The average volume of GTVs in this study was 776cc (range 58-2944cc). Three different SFRT plans (2D GRID technique with conventional collimator, 2D GRID with step & shoot IMRT, and 3D Lattice) were developed for each patient but only Lattice plans were considered in this study since they produced comparable dose modulation inside the tumor but only Lattice significantly reduced skin and critical organ dose. Radio-immune response model always expects longer TRT than LQ model. For palliative regimens, TRT of RI model is longer than that of LQ model by 14.5±9.9, 15.1±10.6, 17.2±12.4, 17.5±12.8 days for each fractionation scheme. When Lattice plan of 15Gy is delivered before the palliative treatment, the difference becomes 25.9±15.3, 31.5±23.3, 36.7±27.6, 37.5±28.5 days. The benefit of SFRT from RI response is only about 10-20 days. Interestingly, RI response is inversely proportional to tumor volume. When curative dose is considered, the difference of TRT is drastically changed from 25.9±9.8, 460.7±285.8, 1180.8±985.7, 1512.0±1327.5 days to 20.7±4.4, 449.0±411.7, 1725.4±2171.0, 3517.7±4531.7 days. The benefit of SFRT from RI response appears larger for large tumor with hypo-fractionation in definitive regimens.

CONCLUSION

The benefit of SFRT is significant for large tumors with hypo fractionation in the definitive regimens when radio-immune response model is considered which is not apparent in LQ model. Radio-immune response model may help to guide the development of successful treatment scheme large tumor volumes.

Radio-Immune Response Model for Radiotherapy Plans with Heterogeneous Dose Distribution

PURPOSE/OBJECTIVE(S)

In order to model the immune response in tumor of the patients under radiotherapy for cancer. Characteristics of the numerical model and preliminary application are presented.

MATERIALS/METHODS

Immune response was modelled by 4 set of ordinary difference equations (ODE) as a function of biomedical variables including the amount of tumor antigen naturally released by tumor, the activation of cytotoxic T-lymphocytes (CTL) by radiation, immune suppression by tumor volume and the use of immunotherapy drugs. The effect of heterogeneous radiation dose distribution is also considered by hyperbolic tangent function to account for the immunogenic response of tissue under highly heterogeneous dose distribution intentionally modulated in spatially fractionated radiotherapy. Boundary behaviors of the model were investigated for tumors with different biomedical characteristics and under different treatment conditions. The developed model was applied to the tumor volume change in a mouse with 67NR tumors after radiation of 10 Gy to full or half volume of tumor and a clinical patient treated for sarcoma three times over 4 years.

RESULTS

Tumor growth is exponential at early phase, slow down over time with increasing immune response and eventually reaches an equilibrium condition (known as terminal tumor volume) for tumors with little to no immune suppression capability (ISC) even in the lack of radiation treatment. Breaking-through the equilibrium for tumor to grow exponentially happens when ISC is larger than the bifurcation threshold, analytically calculated from the proposed model. Tumor with ISC close to the bifurcation threshold can show complex growth behavior depending on the treatment condition and it should be carefully considered for the optimal treatment. Tumor volume change over 30 days period on mouse was modeled well with this model. Full dose irradiation reduced the tumor volume faster in the first 10 days but half volume irradiation reduced the tumor volume faster at later stage due to the improved immune response which cannot be modelled with traditional linear quadratic model. Tumor volume on a patient retreated three times over 4 years was also accurately estimated.

CONCLUSION

The proposed immune response model is capable to estimate tumor volume response under full or partial volume irradiation considering the complex immune characteristics of the tissue.

Abstract P4-06-23: Feasibility of sygeneic mice models of breast cancer for research of immune checkpoint blockades

Background: With the increasing success of immune checkpoint blockades for cancer treatment, we increasingly need well-characterized preclinical models. Syngeneic mice models (with a fully competent immune system) have advantages that they are easily established and cost less, though they do not reflect genetic complexity of human tumors. We evaluated feasibility of syngeneic mice models of breast cancer by analyzing efficacy of immune checkpoint blockade and dynamic change of tumor immune microenvironment.

Methods: We used syngeneic mice model of JC, 4T1, and EMT6 cells, which are all murine triple negative breast cancer in BALB/c mice. At the time when subcutaneous tumors reach at 50˜100mm^3, each mice models were divided into 2 groups for treatment versus no-treatment control. In the treatment group, mice version of anti-PD-1 antibody was intraperitoneally injected (q 3 days, x 6). Anti-tumor efficacy was monitored by measuring tumor volume. 'Tumor response' was defined as a case with tumor volume less than that of control group by a standard error at a determined time point. Immune microenvironment was evaluated by measuring serum cytokines (IL-2, IL-6, IL-10, IFNγ, and TNFα) with legendplex and immune cells (CD3, CD4, CD8, CD56, and FOXP3) of peripheral blood with FACS before injection of PD-1 blockade, after 1st injection, and when euthanized. Tumor-infiltrating immune cells were evaluated with FACS, when euthanized.

Results: The tumor response rate to PD-1 blockade was highest in the 4T1 model (54.5%, 6/11) compared to JC model (40%, 4/10) or EMT6 model (36.4%, 4/11). Bleeding 3 times and tumor obtainment when euthanized in each mouse were feasible for profiling of cytokines and immune cells. Although before treatment with PD-1 blockade, CD3+T cells in peripheral blood were slightly lower in 4T1 model (18.3±8.1%) than JC model (24.6±4.7%) or EMT6 model (27.9±6.3%), after injection of one dose of PD-1 blockade, CD3+T cells increased 1.5 times in 4T1 model (18.3% to 27.3%), whereas those CD3+T cells decreased slightly in JC model and EMT6 model. Dynamic changes were not observed in other subsets of peripheral immune cells in all 3 models. Serum TNFα (with statistical significance) and IFNγ (with borderline significance) were higher in responders than in non-responders or no-treatment control.

Conclusions: Syngeneic mice models of breast cancer were feasible to investigate immune checkpoint blockades and monitor dynamic change of immune microenvironment. In this regard, such models may be used to evaluate immune checkpoint blockade-based combination therapy as well.

Citation Format: Moon YW, Park N, Hur J, Pandey K, Cho YB, Kim SK, Lee SA, Son GW, Jo JM, An H-J. Feasibility of sygeneic mice models of breast cancer for research of immune checkpoint blockades [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-06-23.

Autologous adipose tissue-derived stem cells for the treatment of complex perianal fistulas not associated with Crohn's disease: a phase II clinical trial for safety and efficacy

PURPOSE

Injection of adipose tissue-derived stem cells (ASCs) is a novel method for the treatment of complex perianal fistulas. We aimed to evaluate the safety and efficacy of ASCs in the treatment of complex anal fistulas not associated with Crohn's disease.

METHODS

A phase II clinical trial was performed comparing two different doses of ASCs (group 1: 1 × 10⁷ cells/mL and group 2: 2 × 10⁷ cells/mL). Eligible patients were administered an amount of ASCs proportional to the length of the fistula by injection into the submucosal layer surrounding the internal opening and inside of the fistula tract. ASCs at twice the initial concentration were administered if complete closure was not achieved within 8 weeks. The efficacy endpoint was the complete closure of fistulas 8 weeks after injection. Patients demonstrating complete closure at week 8 were subjected to follow-up for 6 months.

RESULTS

Fifteen patients were injected with ASCs; thirteen completed the study. Complete closure was observed in 69.2% (9/13) of patients at 8 weeks. Three of five patients in group 1, and six of eight in group 2 displayed complete closure; no significant differences were observed between the groups. Six of nine patients who showed complete closure participated in additional follow-up; five (83.3%) showed persistent response at 6 months. No grade 3 or 4 adverse events (AEs) were observed; observed AEs were not related to ASC treatment.

CONCLUSION

ASCs might be a good option for the treatment of complex perianal fistulas are not healed by conventional operative procedures.

Endoscopic submucosal dissection or transanal endoscopic microsurgery for nonpolypoid rectal high grade dysplasia and submucosa-invading rectal cancer

BACKGROUND AND STUDY AIMS

Transanal endoscopic microsurgery (TEM) has been shown to be highly effective for early rectal cancer, and endoscopic submucosal dissection (ESD) has been introduced to treat noninvasive colorectal neoplasia. The aim of this study was to compare the outcomes of ESD and TEM for superficial early rectal cancer.

PATIENTS AND METHODS

We retrospectively analyzed 63 patients with nonpolypoid rectal high grade dysplasia or submucosa-invading cancer who were treated with ESD or TEM, and compared clinical outcomes and safety between the treatment groups.

RESULTS

30 patients underwent ESD and 33 underwent TEM. For ESD compared with TEM, en bloc resection rates were 96.7% vs. 100% (P = 0.476) and R0 resection rates were 96.7 % vs. 97.0 % (P = 1.000). There were no cases of local recurrence or distant metastasis in either group. Antibiotics were required in 11 patients (36.7%) in the ESD group and 33 (100%) in the TEM group (P < 0.001). There was no difference in net procedure time although ESD was associated with shorter total procedure time and hospital stay than TEM, with mean (standard deviation [SD]) 84.0 (51.2) vs. 116.4 (58.5) min (P = 0.0023), and 3.6 (1.2) vs. 6.6 (3.5) days (P < 0.001), respectively. There were no significant differences in complications between the two groups.

CONCLUSIONS

Both ESD and TEM are effective and oncologically safe for treating nonpolypoid rectal high grade dysplasia and submucosa-invading cancers. ESD has the additional advantages of minimal invasiveness and avoidance of anesthesia. Therefore, ESD could be recommended as a treatment option for superficial early rectal cancers.

Effect of Ginkgo biloba extract on endotoxin-induced labyrinthitis

OBJECTIVE

There are no reports on the therapeutic effect of Ginkgo biloba extract (GBE) on otitis media-induced labyrinthitis. The present study examined whether GBE can protect against cochlear damage induced by intratympanic instillation of lipopolysaccharide (LPS)-induced labyrinthitis.

MATERIALS AND METHODS

Experiments were performed in 20 healthy young male guinea pigs. The control group (n=10) received an intratympanic instillation of LPS (20 μl, 3mg/ml). The experimental group (n=10) received intratympanic instillation of LPS immediately after instillation of GBE (10mg/kg) and then experimental groups received GBE (100mg/kg) by intraperitoneal injection every day for 3 days. Instillation of LPS or LPS immediately after GBE was done in the right ear; the untreated left ear was considered normal. Physiological and morphological changes were evaluated.

RESULTS

Statistical analysis of treatment of GBE revealed significantly less hearing loss than LPS group (p<0.05). The ratio of the value of cochlear blood flow (CBF) compared to untreated left side was significantly higher in the GBE treated group than in the LPS-treated group (p<0.05). This result indicated the recovery of CBF in GBE treated group compared to LPS treated group. In the LPS group, scanning electron microscopy revealed hair cell damage with edema. Missing stereocilia in the third layer of the outer hair cell was revealed. However, both the inner hair cells and the outer hair cells had normal appearance in the GBE group. LPS group showed that cochlear Evans blue extravasation was increased strongly in the stria vascularis, spiral limbus, and in the spiral ligament compared with the GBE treated group.

CONCLUSION

GBE significantly minimizes cochlear damage against LPS-induced otitis media with labyrinthitis in a guinea pig model. GBE has potential as an adjunctive therapy to antibiotics in the treatment of acute otitis media with complicated labyrinthitis.

Effect of piperacillin-tazobactam coated β-tricalcium phosphate for mastoid obliteration in otitis media

BACKGROUND AND OBJECTIVE

β-Tricalcium phosphate (TCP) has good biodegradability and osteoconductivity as a scaffold material for bone tissue engineering. Both block and granular forms are available; however, it has been associated with risk of infection and exposure. To this end, the study evaluated the effect of piperacillin-tazobactam coated β-TCPs for mastoid obliteration in otitis media.

MATERIALS AND METHODS

Ten guinea pigs were divided into the experimental (piperacillin-tazobactam coated β-TCP granules, n=5) and control groups (uncoated β-TCP granules, n=5). After mastoid obliteration, transtympanic injection with a saline suspension of lipopolysaccharide established inflammation. The animals were sacrificed 5 weeks later. Tissue sections were stained with hematoxylin and eosin and examined.

RESULTS

Encapsulation and formation of fibrous capsule by foreign material in the bulla were not evident. The histological evaluation did not reveal inflammatory cells and fibrosis in the piperacillin-tazobactam coated β-TCP group. In contrast, the control group showed numerous inflammatory cells around the implanted uncoated β-TCP granules and incomplete new bone formation.

CONCLUSION

β-TCP is an effective carrier material for piperacillin-tazobactam. The use of piperacillin-tazobactam coated β-TCP may be optimal for mastoid obliteration.

Fate of sudden deafness occurring in the only hearing ear: outcomes and timing to consider cochlear implantation

The present study was undertaken to learn the outcome of patients with idiopathic sudden sensorineural hearing loss (ISSNHL) in their only hearing ear. Timing to conduct a cochlear implantation was also determined in those who did not recover the hearing. The study group comprised 25 patients who confronted ISSNHL in their only hearing ear. A total of 192 patients, who had ISSNHL in one ear and had normal contralateral ear, served as the control. Demographically there were no significant differences between the groups. The recovery rate was similar between the groups: 64.0% in the experimental and 62.5% in the control group. The duration until the recovery of ISSNHL in the only hearing ear was 5-90 days (average 17.6 days). In the experimental group, 8 patients did not recover from ISSNHL, and underwent cochlear implantation in 6 with satisfactory results. These results suggest that the same treatment is applicable for patients with ISSNHL regardless of whether their contralateral ear is deaf or normal. For those who do not recover from ISSNHL in their only hearing ear, culminating in bilateral deafness, we may consider further definitive treatment including cochlear implantation as early as 3 months after initiating the treatment of ISSNHL.

Cholesterol granuloma of the tympanic membrane presenting as a blue eardrum

Intramembranous tympanic membrane cholesterol granuloma (CG) occurs infrequently. Here, the authors report a case of CG in the tympanic membrane presenting as a blue eardrum in the right ear. In addition, a pinhole perforation noted in the anterosuperior area revealed a brown discharge. High-resolution temporal bone CT showed a bulging mass shadow in the middle ear and a soft tissue dense lesion that filled both the epitympanum and mastoid cavity. Tympanomastoidectomy was performed under general anesthesia. New bone formation was confirmed in the mastoid antrum and epitympanum, and the epitympanum was blocked by new bone. The tympanic membrane revealed a round, brownish mass with a glistening surface and a severely thickened pars tensa. We herein report this case and review pertinent medical literature.

The effect of increased inner ear pressure on tympanic membrane vibration

BACKGROUND & OBJECTIVE

It has been suggested that increased inner ear pressure can affect the stiffness of the tympano-ossicular conductive system. However, the published literature contains few studies on changes of middle ear mechanics caused by increased inner ear pressure. In this study, we evaluated the effects of increased inner ear pressure on tympanic membrane vibration in guinea pigs using a laser Doppler vibrometer (LDV).

MATERIALS AND METHODS

We used 10 male guinea pigs (weighing 250 g each) with normal eardrums and Preyer reflexes were used for the experiment. Inner ear pressure was modified by two approaches--directly via a tube placed in the inner ear (n=5) and indirectly via a tube placed in the subaracnoid space (n=5). Slow uniform pressure (microl/min) was infused until constant pressure was maintained. At this time, an artificial endolymph or perilymph was injected with a constant pressure of 100 and 300 mm H2O. We measured the umbo velocity using a LDV.

RESULTS

A positive pressure load decreased the umbo vibration at low frequencies but did not change the umbo vibration at mid and high frequencies. The umbo velocity had a greater reduction for an endolymphatic pressure load than for a perilymphatic pressure load. The largest change in velocity was noted at a frequency of 0.1 kHz. There was no significant change in velocity at higher frequencies, except for 5 kHz.

CONCLUSION

LDV is a good tool to analyze middle ear function and it has the potential indirectly to diagnose an increase in endolymphatic or perilymphatic pressure.

The use of piperacillin-tazobactam coated tympanostomy tubes against ciprofloxacin-resistant Pseudomonas biofilm formation: an in vitro study

BACKGROUND AND OBJECTIVE

Bacterial biofilm formation has been implicated in the high rate of persistent otorrhea after tympanostomy tube insertion. It has been suggested that the tube material may be an important factor in the development of otorrhea. Recently we reported the presence of ciprofloxacin-resistant Pseudomonas aeruginosa (CRPA) biofilms on infected tympanostomy tubes following the use of intractable post-tympanostomy tubes and the onset of otorrhea. In this study, we have evaluated the resistance of piperacillin-tazobactam coated with chitosan on a tympanostomy tube to prevent CRPA biofilm formation in vitro.

MATERIALS AND METHODS

Three sets each of piperacillin-tazobactam coated silicone tubes (n=5), commercial silver-oxide coated silicone tubes (Activent, Silic) (n=5) and control uncoated tympanostomy tubes (Paparella type 1) (n=5) were processed for evaluation. The piperacillin-tazobactam coated tympanostomy tubes were compared with the silver-oxide coated tubes and the uncoated control tubes for resistance to CRPA biofilm formation after in vitro incubation.

RESULTS

Scanning electron microscopy showed that the surface of the silver-oxide coated tube (Activent) formed a thick biofilm with crusts as well as an uncoated tube. In contrast, the surface of a piperacillin-tazobactam coated tympanostomy tube showed virtually no CRPA biofilm formation.

CONCLUSION

The piperacillin-tazobactam coated tympanostomy tube showed resistance to CRPA biofilm formation. The piperacillin-tazobactam coating may be useful to reduce CRPA biofilm formation; however, further in vivo studies are necessary.

A primary large cholesterol cyst of the mastoid presenting with dysgeusia

The occurrence of postoperative secondary cholesterol cysts in the mastoid has been previously reported, however the occurrence of a primary large cholesterol cyst in the mastoid with bony destruction of the facial nerve has rarely been reported. The case report of a 17-year-old female patient with a primary large cholesterol cyst with dysgeusia is presented. Computed tomography and magnetic resonance imaging findings for the lesion distinguish a cholesterol granuloma, cholesteatoma and vascular tumor. The patient underwent a canal wall down mastoidectomy with mastoid obliteration. A dehiscent portion of the mastoid segment of the facial nerve was visible within the cavity; the gross finding of the facial nerve was edematous in appearance. Five years later, there has been no recurrence of disease.

Antibacterial effect of octylcyanoacrylate against ciprofloxacin-resistant Pseudomonas aeruginosa isolates from patients with chronic suppurative otitis media

BACKGROUND

There has been a steady increase in the number of cases of ciprofloxacin-resistant Pseudomonas aeruginosa (CRPA) otorrhea; this is a growing medical concern. For otological surgery in children, octylcyanoacrylate can be an alternative method of closure for surgical incisions. Recent in vitro studies have shown that octylcyanoacrylate is effective as an antimicrobical barrier. To date, there have been only rare reports on the antibacterial effect of octylcyanoacrylate against CRPA. The purpose of this study is to determine the antimicrobial effects of octyl-cyanoacrylate against the CRPA that was isolated from patients with chronic suppurative otitis media.

PATIENTS AND METHODS

Clinical CRPA (n=20) bacteria and ciprofloxacin-sensitive PA (CSPA) (n=20) were obtained from patients. The susceptibilities to various antibiotics were determined by disk diffusion method.

RESULT

Both CSPA and CRPA were resistant to octylcyanoacrylate.

CONCLUSION

Results demonstrated that octylcyanoacrylate has no antibacterial activity against CSPA and CRPA.

Huge cholesterol granuloma of the middle ear extending to middle cranial fossa

Cholesterol granuloma (CG) may erode into the middle ear, the mastoid bone and the petrous apex. However, aggressive erosion into the cranial cavity is extremely rare. Here we report a case of huge CG extending to the middle cranial fossa. Temporal bone computerized tomography showed a soft tissue mass which destroyed the bony plate of the posterior and middle cranial fossa. On magnetic resonance imaging, the mass revealed a high signal on both T1 and T2-weighted images. The mass compressed the middle cranial fossa without invasion into the brain. The CG was removed by extended cortical mastoidectomy. The postoperative course was uneventful and there were no neurological complications.

Effects of dehydroepiandrosterone on Th2 cytokine production in peripheral blood mononuclear cells from asthmatics

BACKGROUND/AIMS

The androgen dehydroepiandrosterone (DHEA) attenuates allergic inflammatory airway reactions by down-regulating the Th2 response in mice. The purpose of this study was to investigate whether DHEA suppresses Th2 cytokine production in cultured peripheral blood mononuclear cells (PBMCs) from asthmatic patients.

METHODS

Sixty-one consecutive suspected asthmatic or non-asthmatic men underwent tests for asthma. PBMCs from each subject were cultured with and without DHEA (0.01~10 microM) for 48 h. The concentrations of interferon (IFN)-gamma, interleukin (IL)-5, and IL-10 in the culture supernatant were measured via an enzyme-linked immunosorbent assay.

RESULTS

In PBMCs from subjects exhibiting methacholine airway hyperresponsiveness (AHR), DHEA significantly suppressed IL-10, IL-5, and IFN-gamma production in a dose-dependent manner (all p<0.001) and tended to increase the IFN-gamma/IL-5 ratio (p=0.087). DHEA (10 microM) suppressed cytokine production to a greater degree in subjects with AHR compared with those without AHR (IL-5: 24.0+/-7.8% vs. 40.9+/-3.6%, p<0.01; IFN-gamma: 29.7+/-7.0% vs. 54.5+/-5.1%, p<0.01). Cytokine suppression was significantly related to AHR, serum total IgE levels, and skin reactivity to house dust mites.

CONCLUSIONS

DHEA suppressed both Th1 and Th2 responses, with a Th1 bias, and the degree of suppression was associated with the severity of AHR or atopy. Therefore, DHEA may be a useful therapy for asthma.

Evaluating the ototoxicity of topical piperacillin-tazobactam

BACKGROUND AND OBJECTIVE

With the increased use of ototopical ciprofloxacin solution, newly evolved bacterial fluoroquinolone resistance has also become more of a problem. The emergence of ciprofloxacin-resistant Pseudomonas aeruginosa (CRPA) has created a new therapeutic challenge in otology. We evaluated the ototoxicity of topical fortified piperacillin-tazobactam solution by performing experiments in young male albino guinea pigs (weight, 250-300 g each).

MATERIALS AND METHODS

Antimicrobial assay by direct contact test using scanning electron microscope was performed. Twenty guinea pigs (250-300 g) were treated with fortified piperacillin-tazobactam solution. In experimental group 1 (n=10), a gelfoam ball impregnated with 120 microl of fortified piperacillin-tazobactam was implanted on the round window membrane by a posterior approach. In experimental group 2 (n=10), 20 microl of fortified piperacillin-tazobactam was injected into the middle ear cavity via silicone tube with a small hole placed in the superior aspect of the bulla by drilling. The drug application through the tube was performed for 7 consecutive days. In control group (n=5), a gelfoam ball impregnated with 120 microl of gentamicin solution (80 mg/2 ml) was implanted on the round window membrane.

RESULTS

The fortified piperacillin-tazobactam 20 microl treated CRPAs showed destruction of their cell membrane in antimicrobial assay by direct contact test. No significant difference in the mean auditory brainstem response (ABR) thresholds before and after drug administration was found for the experimental group. However, significant elevation of the mean ABR thresholds was found for the control group. In experimental group, scanning electron microscopy showed almost normal sterociliary arrangements and surface structure on the inner and outer hair cells. However, significant destruction of outer hair cells was identified in control group.

CONCLUSION

This present study's data suggests that fortified piperacillin-tazobactam solution can be effectively used for topically treating CRPA otorrhea in those patients who suffer with chronic suppurative otitis media.

Osteoma of the incus with congenital cholesteatoma: a case report

Osteomas of the middle ear are rare benign tumors. They commonly arise from the promontory. To date, a total of three cases of osteomas of the ossicles, inseparable from malleus and incus, have been described in the English literature. Among them, only one case osteoma with congenital cholesteatoma has been reported. Recently a 6-year-old boy with osteoma associated with congenital cholesteatoma presented to our service. The osteoma and congenital cholesteatoma were removed successfully by canal wall up mastoidectomy with staging operation. A rock-hard mass was separated from the footplate. The malleus and short process of incus were intact. Histopathological examination confirmed the presence of the osteoma.

The effect of anti-adhesive packing agents in the middle ear of guinea pig

BACKGROUND & OBJECTIVE

The presence of adhesions after middle ear surgery is not uncommon. Fibrosis can cause conductive hearing loss and it contributes to retraction of the tympanic membrane in the post-surgery patient. The purpose of this study was to evaluate the anti-adhesive effect of Seprafilm and MeroGel in the abraded mucosa of a guinea pig's middle ear.

MATERIALS AND METHODS

Fifteen pathogen-free adult male albino guinea pigs weighing 250-300g each were used. Under an aseptic condition, the middle ear mucosa was abraded using a pick through a myringotomy incision. Seprafilm, MeroGel and Gelfoam, respectively, were then packed into guinea pigs' middle ear cavities. Auditory brainstem responses (ABRs) were assessed preoperatively and 3 weeks after operation.

RESULTS

The ABR results at postoperative week 3 showed no statistically significant difference for the myringotomy and postpacking, except for the MeroGel packing. However, there was no significant threshold on the 6 weeks' postoperative ABR. The Gelfoam group demonstrated extensive fibrosis and adhesion within the bulla cavity. The Seprafilm and MeroGel groups showed no adhesion in the middle ear cleft after abrasion of the mucosa.

CONCLUSION

From these results, we suggest the use of Seprafilm and MeroGel to improve the results of otosurgery.

Local recurrence after curative resection in patients with colon and rectal cancers

BACKGROUND AND AIMS

There are a range of rates and a number of prognostic factors associated with the local recurrence of colorectal cancer after curative resection. The aim of this study was to identify the potential prognostic factors of local recurrence in patients with colon and rectal cancers.

MATERIALS AND METHODS

A retrospective review of 1,838 patients who underwent curative resection of non-metastatic colorectal cancer was conducted. The patients were treated between 1994 and 2004, and had a minimum follow-up of 3 years.

RESULTS

There were 994 patients with colon cancer and 844 patients with rectal cancer. The median duration of follow-up was 60.9 +/- 24.5 months. With respect to colon cancer, the local recurrence rate was 6.1% (61 patients). With respect to rectal cancer, 95 patients had a local recurrence (11.3%), the rate of which was statistically greater than the local recurrence rate for colon cancer (p < 0.001). The overall recurrence rate was 16.4% (301 patients), and the local recurrence rate, with or without systemic metastases, was 8.5% (156 patients). Local recurrences occurred within 2 and 3 years in 59.9% and 82.4% of the patients, respectively. In patients with colon and rectal cancer, the pathologic T stage (p = 0.044 and p = 0.034, respectively), pathologic N stage (p = 0.001 and p < 0.001, respectively), and lymphovascular invasion (p = 0.013 and p = 0.004, respectively) were adverse risk factors for local recurrence. The level of the anastomosis from the anal verge was an additional prognostic factor (p = 0.007) in patients with rectal cancer.

CONCLUSION

Compulsive follow-up care of patients with colon and rectal cancers is needed for 3 years after curative resection, especially in patients who have adverse risk factors for local recurrence.

Antibacterial effect of octylcyanoacrylate against methicillin-resistant Staphylococcus aureus isolates from patients with chronic suppurative otitis media

There has been a steady increase in the number of cases of methicillin-resistant Staphylococcus aureus (MRSA) otorrhea; this is a growing medical concern. For otological surgery in children, octylcyanoacrylate can be an alternative method of closure for surgical incisions. Recent in vitro studies have shown that octylcyanoacrylate is effective as an antimicrobical barrier. To date, there have been only rare reports on the antibacterial effect of octylcyanoacrylate against MRSA. The purpose of this study is to determine the antimicrobial effects of octylcyanoacrylate against the MRSA that was isolated from patients with chronic suppurative otitis media.

MATERIALS AND METHODS

Clinical MRSA (n=20) bacteria and methicillin-sensitive SA (MSSA) (n=20) were obtained from patients. The susceptibilities to various antibiotics were determined by disk diffusion method.

RESULTS

MSSA was sensitive to octylcyanoacrylate. The antibacterial activity of octylcyanoacrylate was weak against MRSA.

CONCLUSION

Our results demonstrated that octylcyanoacrylate has slight antibacterial activity against MRSA.

The effect of Interceed for reducing adhesion as a middle ear packing agent: an experimental study

BACKGROUND AND OBJECTIVE

Interceed (oxidized regenerated cellulose) has been used to prevent postoperative abdominal adhesion. However, the efficacy and safety of using Interceed in middle ear surgery have not been thoroughly studied.

MATERIALS AND METHODS

The animals were divided into two groups: the Interceed group and the Gelfoam (Gelatin sponge) group. In every group, the study was performed on five guinea pigs (ten ears). Under the aseptic condition, the middle ear mucosa was abraded using a pick through a myringotomy incision. Interceed and Gelfoam were then packed into the guinea pigs' middle ear cavities. The auditory brainstem responses (ABRs) were assessed preoperatively and at 3 weeks after the operation with the animals under general anesthesia. Histopathologic study was performed 3 weeks after the operation.

RESULTS

The ABR results on postoperative week 3 showed no statistically significant difference for myringotomy and postpacking. The fibrosis, middle ear mucosa thickening and adhesion formation appeared to be less in the Interceed group compared with the Gelfoam group. Any foreign body reaction was not observed in the Interceed group.

CONCLUSION

Our results show that Interceed is nonototoxic and biocompatible with the guinea pig's middle ear cavity. Therefore, these results suggest that Interceed could be used safely in the middle ear as a middle ear packing agent during otosurgery.

Congenital cholesteatoma extending into the internal auditory canal and cochlea: a case report

We report here on a case of congenital cholesteatoma that extended into the internal auditory meatus and cochlea. A 17-year-old boy underwent surgery for a very large cholesteatoma, which was discovered behind an intact tympanic membrane. Pure tone audiometry revealed an unresponsive ear. High resolution temporal bone computed tomography showed perilabyrinthine extension with its absence in the vestibular area, and destruction of the bony cochlea at the basal turn, the tegmen and the posterior cranial fossa. Magnetic resonance imaging revealed no intracranial extension. Surgical exploration of the middle ear and the mastoid cavity revealed that both the vestibule and the basal turn of the cochlea were filled with a noninfected cholesteatoma. The cholesteatoma extended into the internal auditory meatus through translabyrinthine destruction; it extended into the basal turn of the cochlea through the infralabyrinthine route. The bony segment of the facial nerve canal demonstrated near total dehiscence. The cholesteatoma was removed by the transotic approach. Congenital cholesteatoma is characterized by no specific history. Therefore, early detection of this malady can be challenging, but it is important to prevent such complications as were observed in this reported case.

Geometric calibration of a mobile C-arm for intraoperative cone-beam CT

A geometric calibration method that determines a complete description of source-detector geometry was adapted to a mobile C-arm for cone-beam computed tomography (CBCT). The non-iterative calibration algorithm calculates a unique solution for the positions of the source (X(s), Y(s), Z(s)), detector (X(d), Y(d), Z(d)), piercing point (U(o), V(o)), and detector rotation angles (phi, theta, eta) based on projections of a phantom consisting of two plane-parallel circles of ball bearings encased in a cylindrical acrylic tube. The prototype C-arm system was based on a Siemens PowerMobil modified to provide flat-panel CBCT for image-guided interventions. The magnitude of geometric nonidealities in the source-detector orbit was measured, and the short-term (approximately 4 h) and long-term (approximately 6 months) reproducibility of the calibration was evaluated. The C-arm exhibits large geometric nonidealities due to mechanical flex, with maximum departures from the average semicircular orbit of deltaU(o) = 15.8 mm and deltaV(o) = 9.8 mm (for the piercing point), deltaX and deltaY = 6-8 mm and deltaZ = 1 mm (for the source and detector), and deltaphi approximately 2.9 degrees, deltatheta approximately 1.9 degrees, and delta eta approximately 0.8 degrees (for the detector tilt/rotation). Despite such significant departures from a semicircular orbit, these system parameters were found to be reproducible, and therefore correctable by geometric calibration. Short-term reproducibility was < 0.16 mm (subpixel) for the piercing point coordinates, < 0.25 mm for the source-detector X and Y, < 0.035 mm for the source-detector Z, and < 0.02 degrees for the detector angles. Long-term reproducibility was similarly high, demonstrated by image quality and spatial resolution measurements over a period of 6 months. For example, the full-width at half-maximum (FWHM) in axial images of a thin steel wire increased slightly as a function of the time (delta) between calibration and image acquisition: FWHM=0.62, 0.63, 0.66, 0.71, and 0.72 mm at delta = 0 s, 1 h, 1 day, 1 month, and 6 months, respectively. For ongoing clinical trials in CBCT-guided surgery at our institution, geometric calibration is conducted monthly to provide sufficient three-dimensional (3D) image quality while managing time and workflow considerations of the calibration and quality assurance process. The sensitivity of 3D image quality to each of the system parameters was investigated, as was the tolerance to systematic and random errors in the geometric parameters, showing the most sensitive parameters to be the piercing point coordinates (U(o), V(o)) and in-plane positions of the source (X(s), Y(s)) and detector (X(d), Y(d)). Errors in the out-of-plane position of the source (Z(s)) and detector (Z(d)) and the detector angles (phi, theta, eta) were shown to have subtler effects on 3D image quality.

Antibacterial effect of tea-tree oil on methicillin-resistant Staphylococcus aureus biofilm formation of the tympanostomy tube: an in vitro study

The antibacterial effects of tea-tree oil against the formation of methicillin-resistant Staphylococcus aureus (MRSA) biofilm on the surface of the tympanostomy tubes was evaluated.

MATERIALS AND METHODS

Silicone tympanostomy tubes were pretreated with normal saline for 12 hours, the control group (n=4), with 100% tea-tree oil, experimental group A (n=3), or with 50% tea-tree oil, experimental group B (n=3). All the tubes were incubated in a MRSA solution for 2 days and then processed for evaluation using scanning electron microscopy.

RESULTS

The development of the biofilm mode of growth of MRSA was observed in the saline-treated control group. In contrast, only focal biofilms were present on the tube surface in experimental group A and considerable reduction of biofilm with destruction of the MRSA cells was shown in experimental group B.

CONCLUSION

From these results, the antimicrobial effect of tea-tree oil against biofilm formation on tympanostomy tubes in vitro has been verified.

Effect of topical dexamethasone on sensorineural hearing loss in endotoxin-induced otitis media

Sensorineural hearing loss, which is limited to the cochlear basal turn, due to acute or chronic otitis media has been reported in clinical and experimental studies. In the present study, the effect of intratympanic dexamethasone on endotoxin-induced cochlear damage was investigated by measuring the cochlear blood flow and hearing.

MATERIALS AND METHODS

Ten male Sprague-Dawley rats were inoculated with lipopolysaccharide (LPS), and divided into 2 groups of five rats each. One hour after intratympanic inoculation, the group A received 40 microl of phosphate-buffered saline (PBS) in the right middle ear cavity, group B received 40 microl of dexamethasone. The treated animals were examined 24 h after inoculation using auditory brainstem response (ABR) and cochlear blood flow (CBF).

RESULTS

The elevated threshold decreased significantly after intratympanic dexamethasone administration compared to the PBS-treated group. Intratympanic dexamethasone administration to the round window of rats led to a statistically significant increase in CBF compared to the PBS-treated group (p <0.05). The response to round window application of prostaglandin E1 (PGE1) in the dexamethasone-treated group was better than in the PBS-treated group.

CONCLUSION

Our results showed that intratympanic dexamethasone treatment was effective in protecting the function of the cochlea against endotoxin-induced otitis media.

Cochlear tolerance of Nd:YAG laser myringotomy

AIM

The objective of this study was to assess whether Nd:YAG laser myringotomy has a negative effect on the cochlea.

MATERIALS AND METHODS

Ten adult guinea pigs with a normal Preyer's reflex were treated by myringotomy with an Nd:YAG laser (power output 8-10W) under surgical microscopic guidance. Preoperative and immediately postoperative hearing tests were performed using auditory brainstem response. The cochlear hair cells were investigated by scanning electron microscope (SEM).

RESULTS

The mean postoperative hearing threshold of the auditory brainstem response showed an insignificant elevation. SEM findings revealed normal outer and inner hair cells after laser myringotomy.

CONCLUSION

No negative effect of Nd:YAG laser myringotomy on the cochlea was found. From these results, it can be concluded that the Nd:YAG laser is safe and effective for myringotomy.

Evaluation of bioactive glass for mastoid obliteration: a guinea pig model

BACKGROUND

Mastoid obliteration seeks to replace an open mastoid cavity with material that will become viable and free of infection and cholesteatoma. The purpose of this study was to evaluate the efficacy of bioactive glass ceramic particles for mastoid obliteration using a guinea pig animal model.

MATERIALS AND METHODS

Ten male guinea pigs (weighing 250-300 g) with normal eardrums and Preyer reflexes were used. Bulla obliteration using bioactive glass was performed on the left side in all guinea pigs. The implanted bioactive glass ceramic particles were examined clinically and radiologically by computed tomography (CT) and histologically.

RESULTS

Clinically, there were no signs of inflammation, infection or implant exposure in all guinea pigs. The CT scans showed hyperintense areas that represented new bone formation. Histological evidence of new bone formation was observed in the implant specimens that included: active osteoblasts, osteocytes, chondrocytes and osteoid tissue. There was a definite bond between the implant and the bone interface at the areas of new bone formation. No inflammatory or foreign body reactions, caused by the bioactive glass ceramic particle implantation, were observed in the surrounding tissue.

CONCLUSION

Our results suggest that bioactive glass ceramic particles are an ideal implant material. Further studies on bioactive glass ceramic particles should include a larger animal trial to lay the groundwork for human studies.

Typical carcinoid tumor of the nasal cavity

The nasal cavity is a rare site of origin of neuroendocrine tumors. They can be classified typical carcinoid, atypical carcinoid and small cell carcinoma, neuroendocrine type. The tumor histology and prognosis correlate closely. The typical carcinoid tumors are well differentiated with benign course. The treatment of the typical carcinoid is a conservative surgery and the prognosis is good. But, typical carcinoid tumor of the nasal cavity was extremely rare, so the treatment has not been established. We report a case of typical carcinoid tumor of the nasal cavity in a 76-year-old man who treated by conservative surgery using sinus endoscopy. To the best of our knowledge this is the first report on an typical carcinoid in the nasal cavity.

A case of malignant otitis externa caused by Candida glabrata in a patient receiving haemodialysis

A 74-y-old male receiving haemodialysis presented with right-sided otalgia, otorrhoea and diffuse swelling on the right external auditory canal. Following an initial successful treatment with prolonged intravenous antibiotics, the patient relapsed with a secondary infection in the same site due to Candida glabrata. We report an unusual case of malignant otitis externa caused by the fungus C. glabrata.

Three cases of organized hematoma of the maxillary sinus

Organized hematoma of the maxillary sinus is a rare clinical disease. To our knowledge, only a few cases of organized hematoma of the maxillary sinus have previously been published, most coming without bleeding history and disorders. We report three cases of organized hematoma of the maxillary sinus presenting with an enlarging maxillary sinus mass. In the evaluation of a patient with recurrent nasal bleeding, nasal obstruction, and an enlarging maxillary mass, organized hematoma of the maxillary sinus should be included in the differential diagnosis.

A novel four-dimensional radiotherapy method for lung cancer: imaging, treatment planning and delivery

We present treatment planning methods based on four-dimensional computed tomography (4D-CT) to incorporate tumour motion using (1) a static field and (2) a dynamic field. Static 4D fields are determined to include the target in all breathing phases, whereas dynamic 4D fields are determined to follow the shape of the tumour assessed from 4D-CT images with a dynamic weighting factor. The weighting factor selection depends on the reliability of patient breathing and limitations of the delivery system. The static 4D method is compared with our standard protocol for gross tumour volume (GTV) coverage, mean lung dose and V20. It was found that the GTV delineated on helical CT without incorporating breathing motion does not adequately represent the target compared to the GTV delineated from 4D-CT. Dosimetric analysis indicates that the static 4D-CT based technique results in a reduction of the mean lung dose compared with the standard protocol. Measurements on a moving phantom and simulations indicated that 4D radiotherapy (4D-RT) synchronized with respiration-induced motion further reduces mean lung dose and V20, and may allow safe application of dose escalation and CRT/IMRT. The motions of the chest cavity, tumour and thoracic structures of 24 lung cancer patients are also analysed.

Pneumocephalus secondary to mastoid surgery: a case report

Pneumocephalus secondary to mastoid surgery is uncommon. Serious sequelae and central nervous system infection may result from inadequate management. It is diagnosed by careful history, physical examination and imaging studies. Treatments of pneumocephalus secondary to mastoid surgery are conservative treatment or surgery. The aim of surgery is to detect communication between mastoid cavity and brain, and to correct it. We present a case of pneumocephalus secondary to mastoid surgery in 22-year-old man, which was treated with surgery.

Endoscopy-aided laser therapy for intractable granular myringitis

Objective: We report our technique and results for endoscopy-aided CO2 laser therapy for the treatment of intractable granular myringitis, as an out-patient office procedure.

Materials and methods: A total of 21 patients (14 women and seven men; mean age 32.6 years) were retrospectively reviewed, all of whom suffered from intractable granular myringitis and had undergone endoscopy-aided laser treatment. Granulation tissue was vaporized for one to two seconds with a CO2 laser (spot size 0.5–1 mm with a power setting of 5–10 W in continuous mode). The mean follow-up period was 11 months.

Results: Eighteen of the 21 patients (85 per cent) were cured after a single treatment. Three patients with the diffuse form of the disease required repeat laser treatments coupled with self-irrigation with a diluted vinegar solution. We noted no perforations of patients' tympanic membranes after laser vaporization. We also observed no recurrences over follow-up periods ranging from three months to 2.6 years. Our laser procedure produced no adverse effect on hearing thresholds, nor were any other complications observed.

Conclusion: Our results suggest that endoscopy-aided CO2 laser ablation is a reliable and minimally invasive method associated with low rates of recurrence and a low incidence of complications. It can be conducted as an office procedure.

The effect of postural restrictions in the treatment of benign paroxysmal positional vertigo

The treatment of benign paroxysmal positional vertigo (BPPV) consists of a repositioning maneuver in order to remove otoliths from the posterior semicircular canal and subsequent postural restrictions to prevent debris from reentering the canal. However, the extent to which postural restrictions affect the final outcomes of BPPV is still uncertain. The purpose of this study is to determine the effects of postural restrictions in the treatment of BPPV, which is caused by otoliths in the posterior semicircular canal, and to evaluate its usefulness as a therapy. Seventy cases diagnosed as BPPV of the posterior semicircular canal were studied. All patients were treated utilizing the modified Epley maneuver. They were divided into two groups. The first group (group A, 35 patients) was instructed to sleep in a semi-sitting position and to avoid moving their heads forward or backward, whereas no instructions were given to the second group (group B, 35 patients). The information gathered from the patients was analyzed by age of onset, gender, duration of the disease and cure rates or recurrence rates. In group A, the average age was 54.5 years and the mean duration of symptoms was 116.5 days, whereas in group B, these measurements were 54.8 years and 86.7 days. The cure rates were 91.4 and 94.3%, respectively. Symptoms recurred in 12.5% of group A patients, while in group B, there was a 9.1% recurrence rate. Our study did not show any significant difference between the two groups. Postural restriction therapy, practiced after the modified Epley repositioning maneuver, did not have a significant effect on the final outcomes of BPPV. Based on our results, we do not recommend this therapy since there was no significant benefit for the patients who utilized postural restrictions.

Otoacoustic emissions in an aberrant internal carotid artery: a case report

A 52-year-old Korean woman who complained of impaired hearing and tinnitus of the left ear was diagnosed with an aberrant internal carotid artery (ICA) in the middle ear using a temporal bone high resolution CT (HRCT) scan. Upon otoscopic examination, her left eardrum was found to be in contact with a mass in the middle ear cavity. Upon audiometric evaluation, a mild conductive hearing impairment was documented, and a discrepancy in the results of otoacoustic emissions (OAEs) was found for the left ear. This case report studies the aberrant ICA in the middle ear that revealed abnormal OAE findings.

Excitatory effects of 5-hydroxytryptamine on the medial vestibular nuclear neuron via the 5-HT2 receptor

This study was designed to investigate the mechanisms of action of the 5-HT2 receptor on the spontaneous electrical activity and potassium currents of the rat medial vestibular nuclear neurons using whole-cell patch clamp recordings. The spike width of spontaneous action potential was not affected by 5-alpha-methylhydroxytryptamine. The spike frequency and resting membrane potential was increased by 5-alpha-methylhydroxytryptamine. The amplitude of afterhyperpolarization was decreased by 5-alpha-methylhydroxy-tryptamine. The peak current of the potassium currents of the neuron treated with 5-alpha-methylhydroxytryptamine was decreased. After blockade of calcium-dependent potassium currents, 5-alpha-methylhydroxytryptamine did not inhibit potassium currents. These results suggest 5-alpha-methylhydroxytryptamine increases spontaneous firing of the medial vestibular nuclear neurons by inhibiting calcium dependent potassium currents.

Effect of SKI 306X, a new herbal anti-arthritic agent, in patients with osteoarthritis of the knee: a double-blind placebo controlled study

SKI 306X is a purified extract from a mixture of three oriental herbal medicines (Clematis mandshurica, Trichosanthes kirilowii and Prunella vulgaris) that have been widely used for the treatment of inflammatory diseases such as lymphadenitis and arthritis in far East Asia. A double-blind, controlled study was performed to evaluate the efficacy and safety of SKI 306X with placebo in 96 patients with classical osteoarthritis of the knee. Patients were randomized to four treatment groups: placebo, 200 mg, 400 mg and 600 mg of SKI 306X t.i.d.. Clinical efficacy and safety were evaluated for 4 weeks continuous treatment. SKI 306X demonstrated its clinical efficacy, as assessed by 100 mm visual analogue scale (VAS), Lequesne index and patients' and investigators opinion of the therapeutic effect compared with placebo (p<0.01). No significant adverse events were observed in patients treated with SKI 306X. This study demonstrated that SKI 306X, a new herbal anti-arthritic agent provided clinical efficacy in patients with osteoarthritis.

A Phase I study of cis-malonato[(4R,5R)-4,5-bis(aminomethyl)-1,3-dioxolane] platinum(II) in patients with advanced malignancies

BACKGROUND

A Phase I study of cis-malonato[(4R,5R)-4,5-bis(aminomethyl)-1,3-dioxolane] platinum(II) (SKI 2053R), a new platinum derivative, was performed to determine the maximum tolerated dose (MTD), the dose limiting toxicities (DLTs), and the pharmacokinetic profile of SKI 2053R in patients with advanced, refractory malignancies.

METHODS

Twenty-one patients were entered into the study. SKI 2053R was administered with an intravenous infusion over 1 hour every 4 weeks. The SKI 2053R dose was escalated from 40 mg/m(2) up to 480 mg/m(2) using a modified Fibonacci scheme. Pharmacokinetic analysis was done in all patients to determine the total and ultrafiltrable platinum concentrations in both the plasma and the urine.

RESULTS

All patients were evaluable for toxicity and response. There was no significant toxicity with dosages up to 360 mg/m(2). At 480 mg/m(2), two of three patients developed Grade 4 hepatotoxicity, Grade 3 leukopenia and thrombocytopenia, and Grade 2 azotemia and proteinuria. Other toxicity included nausea and emesis, but it was controlled with antiemetics. SKI 2053R did not cause significant neurotoxicity or mucositis. There were 4 patients with stable disease among the 21 patients. Plasma decay of the total and free platinum concentrations was best fitted by using a two-compartment, open model. The terminal plasma half-life of the total platinum after SKI 2053R administration ranged from 63.4 hours to 114.1 hours in dosages ranging from 40 mg/m(2) to 480 mg/m(2) without significant dose dependency. However, the terminal plasma half-life of the free platinum concentration showed a significant dose dependent, incremental pattern. The renal excretion of SKI 2053R measured as platinum ranged from 49% to 75% of the administered dose.

CONCLUSIONS

The MTD of SKI 2053R was 480 mg/m(2). The major DLTs were hepatotoxicity, nephrotoxicity, and myelosuppression. The recommended starting dose for a subsequent Phase II study is 360 mg/m(2) once every 4 weeks.