Translational research of boron neutron capture therapy for spinal cord gliomas using rat model

Boron neutron capture therapy (BNCT) is a type of targeted particle radiation therapy with potential applications at the cellular level. Spinal cord gliomas (SCGs) present a substantial challenge owing to their poor prognosis and the lack of effective postoperative treatments. This study evaluated the efficacy of BNCT in a rat SCGs model employing the Basso, Beattie, and Bresnahan (BBB) scale to assess postoperative locomotor activity. We confirmed the presence of adequate in vitro boron concentrations in F98 rat glioma and 9L rat gliosarcoma cells exposed to boronophenylalanine (BPA) and in vivo tumor boron concentration 2.5 h after intravenous BPA administration. In vivo neutron irradiation significantly enhanced survival in the BNCT group when compared with that in the untreated group, with a minimal BBB scale reduction in all sham-operated groups. These findings highlight the potential of BNCT as a promising treatment option for SCGs.

Right-sided Herpes Zoster Ophthalmicus Complicated by Bilateral Third, Fourth, and Sixth Cranial Nerve Palsies and Syndrome of Inappropriate Antidiuretic Hormone Secretion: A Case Report

Cases of herpes zoster ophthalmicus (HZO) complicated by bilateral ophthalmoplegia are rare, and no cases of bilateral third, fourth, or sixth cranial nerve palsies have been reported. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a rare complication of HZO. We herein report an 80-year-old Japanese woman with right-sided HZO complicated by meningoencephalitis and discuss the pathogenesis of this condition. She developed bilateral third, fourth, and sixth cranial nerve palsies and SIADH almost simultaneously during treatment for HZO. The bilateral cranial palsy spontaneously resolved within a few months.

Streamlined workflow including nurse recognition of conjugate gaze deviation for reduced door-to-puncture time in endovascular thrombectomy: A retrospective study

BACKGROUND

Endovascular thrombectomy is recognized as a pivotal treatment for acute ischemic stroke due to large vessel occlusion. Prolonged door-to-puncture time correlates with decreased patient independence after acute ischemic stroke. This study aimed to assess whether a streamlined workflow, including nurse recognition of conjugate gaze deviation, could reduce door-to-puncture time in endovascular thrombectomy.

METHODS

This study retrospectively reviewed patients with acute ischemic stroke who underwent endovascular thrombectomy between March 2017 and March 2022 and compared a previous workflow with a streamlined workflow implemented in April 2019. In the streamlined workflow, nurses recognized conjugate gaze deviation to identify patients with large vessel occlusions and played a more active role in reducing the door-to-puncture time. We compared time metrics and outcomes, including recanalization status, parenchymal hemorrhage type 2, and favorable outcomes (modified Rankin Scale score 0-2) at three months between the previous and streamlined workflow groups.

RESULTS

After the application of the streamlined workflow, the door-to-puncture time was reduced from 76 min to 68 min (p = 0.014), and the number of patients with a door-to-puncture time of less than 60 min increased (15% vs. 36%, p = 0.002). Outcomes including modified thrombolysis in cerebral infarction ≥ 2b (73% vs. 71%, p = 1.000), parenchymal hemorrhage type 2 (7% vs. 2%, p = 0.281), and favorable outcome (33% vs. 34%, p = 1.000) were comparable between the two groups.

CONCLUSION

Nurse recognition of conjugate gaze deviation contributed to an 8-minute reduction in the door-to-puncture time, demonstrating the potential benefits of an organized workflow in acute ischemic stroke.

Evaluation of the Effectiveness of Boron Neutron Capture Therapy with Iodophenyl-Conjugated closo-Dodecaborate on a Rat Brain Tumor Model

High-grade gliomas present a significant challenge in neuro-oncology because of their aggressive nature and resistance to current therapies. Boron neutron capture therapy (BNCT) is a potential treatment method; however, the boron used by the carrier compounds-such as 4-borono-L-phenylalanine (L-BPA)-have limitations. This study evaluated the use of boron-conjugated 4-iodophenylbutanamide (BC-IP), a novel boron compound in BNCT, for the treatment of glioma. Using in vitro drug exposure experiments and in vivo studies, we compared BC-IP and BPA, with a focus on boron uptake and retention characteristics. The results showed that although BC-IP had a lower boron uptake than BPA, it exhibited superior retention. Furthermore, despite lower boron accumulation in tumors, BNCT mediated by BC-IP showed significant survival improvement in glioma-bearing rats compared to controls (not treated animals and neutrons only). These results suggest that BC-IP, with its unique properties, may be an alternative boron carrier for BNCT. Further research is required to optimize this potential treatment modality, which could significantly contribute to advancing the treatment of high-grade gliomas.

Utility of 5-aminolaevulinic acid fluorescence-guided endoscopic biopsy for malignant mesothelioma in a cat and dog

Malignant mesothelioma (MM) is uncommon in cats and dogs and can be challenging to diagnose. Adequate tissue sampling is required for superior diagnostic accuracy. Protoporphyrin IX, a metabolite of 5-aminolaevulinic acid (5-ALA), is a photosensitiser for photodynamic diagnosis (PDD). To the best of our knowledge, no study has reported the use of 5-ALA-PDD to detect MM in veterinary medicine. The present study describes the use of 5-ALA-PDD for MM diagnosis in a cat and dog, as well as the effectiveness of intracavitary chemotherapy. We evaluated the use of PDD with 5-ALA hydrochloride (5-ALA-PDD) in two cases of MM. A 12-year-old cat presented with a 1-month history of respiratory distress, and a 9-year-old dog presented with a 3-month history of mild abdominal distention. We endoscopically biopsied lesions in both the cases using 5-ALA-PDD. Histopathological examination revealed mesothelioma, and immunohistochemical staining was positive for calretinin. Both patients were treated with carboplatin. The cat died of respiratory failure. Although, the dog's condition improved 21 days after the first chemotherapeutic drug administration, the dog died on day 684 owing to cardiac-related issues. 5-ALA-PDD is thus, safe and feasible for the diagnosis of MM in veterinary medicine.

ET-4 BASIC RESEARCH OF BORON NEUTRON CAPTURE THERAPY USING A NOVEL BORON COMPOUND TARGETED TO INTEGRIN

Background

Boron neutron capture therapy (BNCT) is a particle radiation modality capable of selectively destroying tumor cells. The most commonly used boron compound for BNCT is boronphenylalanine (BPA). BPA is taken up into the tumor cell via the L-type aminoacid transporter (LAT-1). However, there are some BPA-refractory situations. Therefore, a novel boron compound is expected to improve the therapeutic performance of BNCT. We focused on integrinαvβ3, which is overexpressed in malignant gliomas as in many cancer cells, and have developed cRGD-MID-AC, a conjugate of cyclic RGD (cRGD), which selectively inhibited integrinαvβ3, and MID-AC, which we have already reported as effective on BNCT as BPA as a boron compound in F98 rat glioma models. We evaluated the efficacy of BNCT using this novel compound.Methods: F98 glioma cells were exposed to BPA, cRGD-MID-AC, and cRGD-MID for cellular uptake and neutron irradiation experiment. Intracellular boron concentrations and compound biological effectiveness (CBE) for each boron compound was calculated. After intravenous administration (i.v.) of cRGD-MID-AC or BPA, the biodistribution of boron compounds was measured and neutron irradiation experiment were performed in F98 rat glioma models.

Results

Intracellular boron concentrations of BPA and cRGD-MID-AC were increased gradually at all exposed time, and CBE for cRGD-MID-AC was comparable to that for BPA. In cRGD-MID-AC, the boron concentration in the tumor was the highest at 8 h after i.v. and tended to be retained longer at 24h. In vivo neutron irradiation experiment, long-term survival was observed only in the group irradiated 8 h after cRGD-MID-AC i.v.. These experiments suggest that cRGD-MID-AC has sufficient cell-killing effect and may be more effective in vivo.

Conclusion

cRGD-MID-AC has a tumor accumulation mechanism different from that of BPA, and could be an effective boron carrier in BNCT for malignant gliomas.

RT-6 POTENTIAL AND PROSPECTS OF BORON NEUTRON CAPTURE THERAPY USING A COMBINATION OF MULTIPLE BORON AGENTS

Boron neutron capture therapy (BNCT) is a particle therapy that can target tumors at the cellular level. BNCT has been developed for the treatment of malignant gliomas with widely infiltrated tumors, but as the indication for BNCT was expanded to include the whole body, the focus shifted to borophalan-10B (BPA), which is based on the essential amino acid phenylalanine, as a candidate agent. We started BNCT for brain tumors in 2002 with a protocol combining two compounds (BPA, BSH) that had been clinically used, but later, with the development of an accelerator-based system, we conducted a clinical study of a single agent of BPA with a modified administration protocol in a nuclear reactor. In this report, we analyze the clinical studies of BNCT for recurrent malignant glioma using the reactor as a neutron source, and discuss the possibility of BNCT using multiple drugs in combination. The median survival with BSH+BPA was 11.0 months (n=29) overall, and the MST with BPA alone was 11.1 months (n=24), with similar results for BPA alone. The blood boron levels at the time of irradiation were 46.3 and 27.3 μg/ml, respectively, which were higher with the addition of BSH. The irradiation doses converted to X-rays (Gy) equivalent were calculated to be 69 and 76 Gy-Eq for the maximum tumor, 37 and 40 Gy-Eq for the minimum, and 10.9 and 10.5 Gy-Eq for the normal brain, respectively. The biological effectiveness ratios for tumor and normal tissue from neutron capture reactions with boron compounds and tissue boron concentrations were factored into these calculations, and since BPA and BSH have different target systems (BPA in the infiltration zone and BSH in the contrast zone, respectively), we believe that their combined use may improve therapeutic efficacy and attenuate adverse events.

Bilateral Posterolateral Sulcus Approach for the Removal of Spinal Intramedullary Metastatic Adenocarcinoma: A Technical Case Report

Spinal intramedullary metastasis is an extremely rare event that occurs in advanced cancer. The surgical indications for spinal intramedullary metastasis are highly limited because of surgical difficulty and poor prognosis. In this technical case report, we present a rare case of spinal intramedullary metastasis from the lung that recurred late after local radiation to the spinal cord. The patient progressively experienced relapsed buttock pain and developed gait and urination disorders late after treatment for lung cancer. Imaging examinations suggested the recurrence of spinal intramedullary metastasis in the conus medullaris. Systemic examinations revealed no apparent recurrence in other organs, including the primary lung lesions. Gross total resection of the tumor within the conus medullaris was safely performed using the unilateral posterolateral (PLS) approach and by addition of the contralateral PLS approach. To the best of our knowledge, this is the first case in which a spinal intramedullary metastatic tumor was successfully removed using a bilateral PLS approach.

Anatomical Limitation of Posterior Spinal Myelotomy for Intramedullary Hemorrhage Associated with Ependymoma or Cavernous Malformation of the High Cervical Spine

Spinal intramedullary tumors such as ependymoma or vascular lesions such as cavernous malformation are often at risk of intramedullary hemorrhage. Surgical procedures involving the high cervical spinal cord are often challenging. This technical note included four patients who presented with acute, subacute, or gradual onset of spinal cord dysfunction associated with intramedullary hemorrhage at the C1 or C1/2 level of the high cervical spine. The mean age was 46.3 years (16-74 years). All patients underwent posterior spinal cord myelotomy of the posterior median sulcus or posterolateral sulcus. It was not to exceed the caudal opening of the fourth ventricle (foramen of Magendie) and was assumed to be as high as the caudal medulla oblongata. Total removal of the intramedullary ependymoma or cavernous malformation occurred in three of four cases, and the remaining case had subtotal removal of the ependymoma. None of the patients showed postoperative deterioration of the neurological condition. Pathological examination of all cases revealed intramedullary hemorrhage was associated with ependymoma or cavernous malformation. Posterior spinal myelotomy should be limited to the caudal opening of the fourth ventricle (foramen of Magendie), that is the caudal medulla oblongata, to avoid the significant deterioration after surgery.

Evaluation of the Effectiveness of the Tap Test by Combining the Use of Functional Gait Assessment and Global Rating of Change

Background

Although the tap test for patients with suspected idiopathic normal pressure hydrocephalus (iNPH) is still often performed as part of the preoperative evaluation, it is true that some studies have reported the limitations of the tap test, claiming that it does not provide the additional information for appropriate patient selection for surgery. We aimed to determine whether a better method of pre- and post-tap test assessment could lead to appropriate patient selection for shunting.

Methods

We performed the tap test as part of the preoperative evaluation in all 40 patients who underwent lumboperitoneal shunt surgery for iNPH from April 2021 to September 2021. We retrospectively analyzed the patient data. We examined whether a comprehensive evaluation of the effect of the tap test using the Functional Gait Assessment (FGA) and Global Rating of Change (GRC) scales would identify a wider range of patients who would benefit from shunt surgery than the 3-m Timed Up and Go test (TUG) alone.

Results

Assuming a prevalence of 1% for iNPH, the TUG had a sensitivity of 0.23, specificity of 0.71, positive likelihood ratio of 0.79, and negative likelihood ratio of 1.09. When improvement in either the FGA or the GRC was used as a criterion for the validity of the tap test, the sensitivity was 0.88, specificity was 0.17, positive likelihood ratio was 1.06, and negative likelihood ratio was 0.71.

Conclusion

Improvement in either the FGA or the GRC is a more sensitive criterion for the effectiveness of the tap test for the gait aspect than the TUG. Since the negative likelihood ratio is lower than that for the TUG alone, it is more appropriate to exclude patients with neither FGA nor GRC improvement from surgical indications than to exclude surgical indications based on a negative TUG.

Optic Nerve Root Enhancement in Gadolinium-Enhanced Magnetic Resonance Imaging of Rathke's Cleft Cyst

BACKGROUND

Although most patients with Rathke's cleft cysts (RCCs) remain asymptomatic throughout their lives, visual impairment in RCCs usually indicates surgical interventions, including endoscopic drainage of the cyst. We report a case of RCC with unique findings in the optic nerve root (ONR) by magnetic resonance imaging (MRI).

CASE DESCRIPTION

A 58-year-old man admitted to our hospital complained of progressive left visual impairment. Preoperative computed tomography MRI revealed a suprasellar cystic lesion that extended anteriorly, and the bilateral ONRs were lateralized with the cyst and were partially enhanced with gadolinium administration. The cyst content was drained, and the cyst wall was partially removed by endoscopic transsphenoidal surgery. Postoperatively, the patient was administered corticosteroid intravenously for 3 days, and his visual acuity improved dramatically. Postoperative MRI revealed that the volume of the cyst decreased, and the position of the bilateral ONRs normalized. Additionally, enhancement of the ONRs with gadolinium administration was not observed. Histological examination of the surgical specimen revealed a ciliated single-layer columnar epithelium with inflammatory cell infiltration.

CONCLUSIONS

To our knowledge, we report the first case of a patient with RCC with ONR enhancement with gadolinium administration on MRI. This unique finding might prove that inflammation is one of the causes of visual impairment in RCC as in optic neuritis.

Photon number resolving SiPM detector with 1 GHz count rate

We demonstrate 1 GHz count rate photon detection with photon number resolution by using a multi-pixel photon counter (MPPC) and performing baseline correction. A bare MPPC chip mounted on a high-frequency circuit board is employed to increase response speed. The photon number resolving capability is investigated at high repetition rates. This capability remains at a repetition rate of 1 GHz and at rates as high as an average of 2.6 photons detected per optical pulse. The photon detection efficiencies are 16% at λ = 450 nm and 4.5% at λ = 775 nm with a dark count rate of 270 kcps and an afterpulse probability of 0.007.

Multipixel silicon avalanche photodiode with ultralow dark count rate at liquid nitrogen temperature

Multipixel silicon avalanche photodiodes (Si APDs) are novel photodetectors used as silicon photomultipliers (SiPMs), or multipixel photon counter (MPPC), because they have fast response, photon-number resolution, and a high count rate; one drawback, however, is the high dark count rate. We developed a system for cooling an MPPC to liquid nitrogen temperature and thus reduce the dark count rate. Our system achieved dark count rates of <0.2 cps. Here we present the afterpulse probability, counting capability, timing jitter, and photon-number resolution of our system at 78.5 K and 295 K.

Curative intended radiation therapy for young patients with invasive uterine cervical carcinoma: Clinical outcomes in 105 patients in a Japanese multi-institutional study

e16558

Background: Recently, the number of young patients with invasive uterine cervical carcinoma is increasing in Japan because of earlier sexual activity and low rate of receiving screening test of uterine cervical carcinoma in Japan. However, no large studies have been performed so far to evaluate the clinical outcomes of curative intended radiation therapy for young patients with invasive uterine cervical carcinoma in Japan. Then, the current study was designed. Methods: One hundred and five patients under 40 years old were registered in the mulitiinstitutional study. The median age was 34.5 years old (range: 24–39 years old). According to FIGO, clinical stage was as follows. Stage Ib/IIa/IIb/IIIa/IIIb/IVa were 10/4/38/2/47/3, respectively. The median maximal tumor diameter was 5.5 cm (range: 2–9.2 cm). Curative intended radiation therapy was the combination of high-dose rate intracavitary brachytherapy (HDR-ICBT) combined with external beam radiation therapy (ERT). The total dose of ERT ranged from 44 Gy to 68 Gy. The total dose of HDR-ICBT to point A ranged from 12 Gy to 48 Gy. Eighty five patients received chemotherapy. Results: The 5-year overall survival rate and local control rate of all patients was 58.4 % and 59.3 %, respectively. The 5-year overall survival rates of stage Ib/IIa/IIb/IIIa/IIIb/IVa were 90.0 %/not available (NA)/73.8%/100%/37.4%/0%, respectively. The 5-year local control rates of Stage Ib/IIa/IIb/IIIa/IIIb/IVa were 80.0 %/50.0 %/73.8 %/100 %/54.6 %/NA, respectively. Sixteen patients experienced grade 3 or greater late radiation morbidity. Conclusions: Clinical outcomes of stage I-II in the young were equivalent to the Japanese standard treatment results of all ages. However, clinical outcomes of stage IIIb and IVa in the young were worse than those of all ages (5-year OS of all ages in Japan: IIIb: 50 %, IVa: 25 %).

No significant financial relationships to disclose.

Dosimetric predictors of radiation esophagitis in patients treated for non-small-cell lung cancer with carboplatin/paclitaxel/radiotherapy

PURPOSE

To establish dosimetric predictors of radiation esophagitis (RE) in patients treated with a combination of carboplatin, paclitaxel, and radiotherapy.

METHODS AND MATERIALS

Three-dimensional radiotherapy plans of 26 patients with non-small-cell lung cancer who received 50-60 Gy of radiotherapy concurrently with weekly administration of carboplatin (AUC 2) and paclitaxel (40-45 mg/m(2)) were reviewed in conjunction with RE. The factors analyzed included the following: percentages of organ volumes receiving >40 Gy (V40), >45 Gy (V45), >50 Gy (V50), and >55 Gy (V55); the length of esophagus (total circumference) treated with >40 Gy (LETT40), >45 Gy (LETT45), >50 Gy (LETT50), and >55 Gy (LETT55); the maximum dose in the esophagus (Dmax); and the mean dose in the esophagus (Dmean). Data were obtained on the basis of superposition algorithm.

RESULTS

All factors except Dmax showed statistical correlation with RE. Good correlations were shown between RE and LETT45 (rho = 0.714) and V45 (rho = 0.686).

CONCLUSIONS

LETT45 and V45 appear to be useful dosimetric predictors of RE. It is also suggested that Dmax does not predict RE.

[Serological cross-reaction among Bartonella henselae, Chlamydia pneumoniae and Coxiella burnetii by indirect fluorescence antibody method]

We studied the serological cross-reactions among Bartonella henselae, Chlamydia pneumoniae and Coxiella burnetii by indirect fluorescence antibody (IFA) method, using sera from 8 patients with cat scratch disease (CSD), 13 patients with C. pneumoniae infection and 12 patients with acute Q fever. B. henselae IgG antibody was negative in 13 patients with C. pneumoniae infection, and was positive in 3 (titers being 1:64) of 12 patients with Q fever, whereas B. henselae IgM antibody was negative in all the patients with C. pneumoniae infection or Q fever. C. burnetii IgG antibody was removed by absorption of these 3 sera with C. burnetii antigens, whereas B. henselae IgG antibody did not change. C. pneumoniae IgG antibody was positive in 3 (titers being 1:125 in two, 1:32 in one) of 8 patients with CSD. Both C. pneumoniae and B. henselae IgG antibody titers were significantly reduced by absorption of these 3 sera with B. henselae antigens. C. burnetii IgG or IgM antibodies were negative in all patients with CSD. In conclusion, no serological cross-reaction between B. henselae and C. burnetii was observed. On the other hand. B. henselae IgG antibody cross-reacted to C. pneumoniae antigens, whereas C. pneumoniae IgG antibody did not cross-react to B. henselae antigens. Our findings suggest that determination of B. henselae IgG or IgM antibodies were not influenced by C. pneumoniae and C. burnetii antigens.

Endoscopic findings of radiation esophagitis in concurrent chemoradiotherapy for intrathoracic malignancies

BACKGROUND AND PURPOSE

The incidence and extent of radiation esophagitis were assessed endoscopically in patients treated with concurrent chemoradiotherapy.

PATIENTS AND METHODS

Eighty-two patients who received thoracic radiotherapy for lung, thymic, or esophageal cancer were investigated endoscopically from July 1991 to the end of 1997. Among them, 23 esophageal cancer patients were treated with radiation alone, and the others were treated with concurrent chemoradiotherapy. Esophageal endoscopy was performed during or just after radiotherapy. The presence of radiation esophagitis was assessed and assigned an endoscopic score (i.e. grade 0 for normal, 1 for erythema, 2 for erosion or sloughing, 3 for ulcer, hemorrhage, or stricture). The symptomatic grade was assessed using the RTOG (Radiation Therapy Oncology Group) acute radiation morbidity score.

RESULTS

A correlation was seen between endoscopic and RTOG scores. However, even some patients with RTOG grade 0 to 1 had endoscopic grade 3 esophagitis. Endoscopic grade 3 was observed in 16 (27.1%) patients in the concurrent chemoradiotherapy group, whereas it did not occur in any patient in the radiation alone group (P=0.004).

CONCLUSIONS

Our results suggest that (1) RTOG score correlates closely to esophageal mucosal damage, and (2) more severe esophagitis occurs in those undergoing concurrent chemoradiotherapy than those undergoing radiotherapy alone [corrected].