Risk Factors Causing Hypothyroidism in Patients With Head and Neck Cancer After Radiotherapy Using SIB-VMAT.

BACKGROUND/AIM: We evaluated the incidence of radiation-induced hypothyroidism and its risk factors in patients with head and neck cancer who underwent radiotherapy using simultaneous integrated boost-volumetric-modulated arc therapy (SIB-VMAT). PATIENTS AND METHODS: This retrospective study included 86 patients who received definitive radiotherapy using SIB-VMAT for head and neck cancer. The incidence of ≥ grade 2 hypothyroidism was evaluated. We also evaluated the relationships between hypothyroidism development and clinical factors and thyroid dose-volume parameters. RESULTS: During a median follow-up period of 17 months (range=3-65 months), 31 patients (36.0%, 31/86) developed grade 2 hypothyroidism requiring hormone replacement therapy. No patients experienced ≥ grade 3 hypothyroidism. The cumulative incidences of hypothyroidism at 1 and 2 years after radiation therapy were 24.5% and 38.7%, respectively, with a median onset time of 10.0 months (range=3.0-35.0 months). Thyroid volume (p=0.003), volume of the thyroid spared at 60 Gy (VS60; cut-off value, 5.16 ml; p=0.009), VS70 (cut-off value, 8.0 ml; p=0.007), VS60 equivalent dose in 2 Gy fraction (EQD2; cut-off value, 7.78 ml; p=0.001), and VS70EQD2 (cut-off value, 10.59 ml; p=0.008) were significantly associated with the development of radiation-induced hypothyroidism. CONCLUSION: Radiation-induced hypothyroidism is not rare in patients with head and neck cancer undergoing radiotherapy using SIB-VMAT. Radiation dose-volume parameters detected in this study may be useful indicators to prevent this complication.

Clinical Experience of Percutaneous Radiofrequency Ablation Using an arfa RF ABLATION SYSTEMⓇ in Various Organs.

Purpose: To evaluate the feasibility, safety, and efficacy of radiofrequency (RF) ablation using an ablation system (arfa RF ABLATION SYSTEMⓇ; Japan Lifeline Co. Ltd.) for treating solid tumors in various organs. Material and Methods: Between October 2019 and August 2021, 80 patients (29 women, 51 men; median age, 70.0 yr) underwent 107 RF ablation sessions using the ablation system to treat 151 tumors in the liver (n = 86), lung (n = 51), adrenal gland (n = 4), pleura (n = 4), bone (n = 3), lymph node (n = 2), and kidney (n = 1). The maximum tumor diameter was 2-40 mm (median, 11 mm). This study evaluated technical success (defined as the completion of planned RF ablation), technique efficacy (defined as the complete tumor ablation on follow-up images), and adverse events. Local tumor progression in 146 curatively treated malignant tumors was evaluated. Results: The technical success rate was 100% (107/107). Ablation zones in two tumors were insufficient. Therefore, the primary technique efficacy rate was 98.1% (105/107). Grade 3 hepatic infarction (1.6%, 1/64) and grade 4 pleuritis (3.4%, 1/29) occurred respectively after liver and lung RF ablation. During the median follow-up period of 10.2 months (Interquartile range, 4.2 and 16.4 months), local tumor progression developed in two tumors (1.4%, 2/146). Conclusions: The arfa RF ABLATION SYSTEMⓇ is a feasible, safe, and effective RF ablation device for managing solid tumors in various organs.

Protective Effect of Polaprezinc and Hyperbaric Oxygen Therapy on Radiation-induced Small Intestinal Damage in Mice.

BACKGROUND/AIM: To investigate the effect of polaprezinc (antioxidant) administration and hyperbaric oxygen therapy on radiation-induced intestinal injury. MATERIALS AND METHODS: Forty-five C57BL/6J mice underwent total body radiation of 2 Gy. Polaprezinc was given in 12 mice, hyperbaric oxygen in 12 mice, and both in 12 mice. The other 9 mice did not undergo any treatment. Mice were sacrificed 2, 4, and 6 h after radiation, and 9 specimens (3 each from the duodenum, jejunum, and ileum) were harvested. Apoptotic intestinal crypt cells were histologically evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. RESULTS: Apoptotic cell number per 1,000 crypt cells was 31.0±6.7 at 2 h, 28.4±5.2 at 4 h, and 32.9±5.1 at 6 h in the mice group treated by radiation alone. Both polaprezinc administration and hyperbaric oxygen therapy significantly suppressed apoptosis. Although the effect of polaprezinc administration on suppressing apoptosis became less over time (4.9±5.7 and 19.4±13.2 at 2 and 6 h, respectively), that of hyperbaric oxygen therapy was stable regardless of time (23.6±4.8 and 25.8±4.1 at 2 and 6 h). Administration of both polaprezinc and hyperbaric oxygen showed a significant synergetic or additive effect on suppressing apoptosis at 6 h (11.4±10.5, p<0.0035 vs. polaprezinc, p<0.0001 vs. hyperbaric oxygen). CONCLUSION: Both polaprezinc administration and hyperbaric oxygen therapy are effective in relieving radiation-induced small intestinal damage, and a synergistic or additive effect is expected when using both.

Use of Microballoon Catheter in Transarterial Ethanol Embolization of Renal Angiomyolipoma: A Retrospective Comparative Study with Historical Control?

Purpose: To clarify the utility of microballoon catheter in renal arterial ethanol embolization of renal angiomyolipoma (AML). Material and Methods: A total of 20 patients (15 women, 5 men) with median age of 45 years (39-60 years) underwent embolization to treat 22 AMLs. A mixture of ethanol and iodized oil was injected into the feeding arteries of 13 tumors using balloon occlusion (the balloon embolization group) with a microballoon catheter and 9 tumors without using balloon occlusion (the non-balloon embolization group). Changes in the maximum tumor diameter, tumor volume, and adverse events were evaluated. Result: The median baseline maximum tumor diameters and volumes were 6.3 cm and 61.4 cm3 in the balloon embolization group, and 4.6 cm and 40.1 cm3 in the non-balloon embolization group, respectively. Tumor enhancement disappeared on postembolization angiography in all cases. All tumors shrunk after embolization. There were no statistically significant differences in the percent decrease in the maximum tumor diameter and volume at 10-12 month between balloon occlusion group (31.5% and 67.9%) and control group (34.8% and 62.6%). Fever was significantly more frequent when balloon occlusion was used: 38% vs. 0% (p = 0.03). No major complication was observed in either patient group. Conclusions: Balloon occlusion may not affect tumor shrinkage when embolizing AMLs with a mixture of ethanol and lipiodol.

CT Findings of Primary Renal Angiosarcoma.

Primary angiosarcomas of the kidney are very rare but highly aggressive tumors showing poor prognosis. We present a case of primary renal angiosarcoma occurring in a 60-year-old man with left flank pain. CT images depicted a huge exophytic mass (14 cm in diameter) in the left kidney, exhibiting central extensive hemorrhage or necrosis without contrast enhancement. The mass showed centripetal peripheral nodular enhancement on dynamic contrast-enhanced CT images. We suggest its inclusion in the differential diagnosis of cases of hemorrhagic renal tumors with prominent vasculature.

Metastasis-Directed Radiotherapy for Oligoprogressive Castration-Resistant Prostate Cancer Recurrence Revealed by Choline PET/CT.

We report a 49-year-old male with castration-resistant prostate cancer (CRPC) with oligometastasis diagnosed by 11C-choline positron emission tomography-computed tomography (PET/CT) and treated with target radiotherapy. In the diagnosis of CRPC (serum prostate-specific antigen [PSA] level of 6.53 ng/mL after maximum androgen blockade (MAB) therapy, high-dose brachytherapy, and external beam radiotherapy), 11C-choline PET/CT detected one tiny obturator lymph node metastasis which fluorodeoxyglucose PET/CT could not detect. He underwent intensity-modulated radiation therapy and MAB was restarted. The PSA value decreased and reached nadir (0.091 ng/mL) after 6 months. The time to PSA progression was 10 months. The choline PET/CT finding and the corresponding local treatment could play an important role in the management sequence of oligoprogressive CRPC.