Intracavitary Radiation Therapy for Recurrent Cystic Brain Tumors with Holmium-166-Chico : A Pilot Study

Ha, Eun Jin,Gwak, Ho-Shin,Rhee, Chang Hun,Youn, Sang Min,Choi, Chang-Woon,Cheon, Gi Jeong The Korean Neurosurgical Society 2013 Journal of Korean neurosurgical society Vol.54 No.3

Objective : Intracavitary injection of beta-emitting radiation source for control of cystic tumors has been tried with a benefit of localized internal radiation. The authors treated cystic brain tumor patients with Holmium-166-chitosan complex (Ho-166-chico), composed of a beta-emitting radionuclide Holmium-166 and biodegradable chit polymer, and evaluated the safety and effective measurement for response. Methods : Twenty-two patients with recurrent cystic brain tumor and/or located in a deep or eloquent area were enrolled in this pilot study. The cyst volume and wall thickness were determined on CT or MRI to assess radiological response. The activity of Ho-166-chico injected via Ommaya reservoir was prescribed to be 10-25 Gy to the cyst wall in a depth of 4 mm. Results : There was neither complications related to systemic absorption nor leakage of Ho-166-chico in all 22 patients. But, two cases of oculomotor paresis were observed in patients with recurrent craniopharyngioma. Radiological response was seen in 14 of 20 available follow-up images (70%). Seven patients of 'evident' radiological response experienced more than 25% decrease of both cyst volume and wall thickness. Another 7 patients with 'suggestive' response showed decrease of cyst volume without definitive change of the wall thickness or vice versa. All patients with benign tumors or low grade gliomas experienced symptomatic improvement. Conclusion : Ho-166-chico intracavitary radiation therapy for cystic tumor is a safe method of palliation without serious complications. The determination of both minimal effective dosage and time interval of repeated injection through phase 1 trial could improve the results in the future.

Ventriculolumbar Perfusion Chemotherapy With Methotrexate for Treating Leptomeningeal Carcinomatosis: A Phase II Study

Gwak, Ho-Shin,Joo, Jungnam,Shin, Sang-Hoon,Yoo, Heon,Han, Ji-Youn,Kim, Heung Tae,Yun, Tak,Ro, Jungsil,Lee, Jin Soo,Lee, Seung Hoon AlphaMed Press 2014 The oncologist Vol.19 No.10

<P><B>Background.</B></P><P>The efficacy of ventriculolumbar perfusion (VLP) chemotherapy with methotrexate (MTX) was evaluated for treatment of leptomeningeal carcinomatosis (LMC).</P><P><B>Methods.</B></P><P>The primary outcome was the response rate of increased intracranial pressure (ICP), which was available for comparison from historical data on conventional intraventricular chemotherapy. Secondary endpoints were response rates of other LMC symptoms and overall survival of patients. Artificial cerebrospinal fluid (CSF) premixed with MTX was continuously perfused intraventricularly through a preinstalled intraventricular reservoir and drained via lumbar catheter for 72 hours. The VLP was repeated twice at 3-day intervals for each cycle.</P><P><B>Results.</B></P><P>Forty-five of 65 patients had increased ICP, and 32 patients (71%) showed response after VLP chemotherapy, including 31 patients with normalization of ICP. Altered mentation improved in 7 of 21 patients (33%). Cauda equina symptoms responded in 5 of 27 patients (19%), including 4 patients who became ambulatory from a bedridden state. Median overall survival was 187 days, and the 1-year survival rate was 27%. All side effects, including nausea, vomiting, confusion, and sleep disturbance, were tolerable and transient except for two cases of CSF infection.</P><P><B>Conclusion.</B></P><P>VLP chemotherapy with MTX provided better control of increased ICP, improved symptom response, and prolonged survival at a cost of acceptable toxicity in patients with LMC.</P>

Chemotherapy for Malignant Gliomas Based on Histoculture Drug Response Assay : A Pilot Study

Gwak, Ho-Shin,Park, Hyeon-Jin,Yoo, Heon,Youn, Sang-Min,Rhee, Chang-Hun,Lee, Seung-Hoon The Korean Neurosurgical Society 2011 Journal of Korean neurosurgical society Vol.50 No.5

Objective : The Histoculture Drug Response Assay (HDRA), which measures chemosensitivity using minced tumor tissue on drug-soaked gelfoam, has been expected to overcome the limitations of in vitro chemosensitivity test in part. We analyzed interim results of HDRA in malignant gliomas to see if the test can deserve further clinical trials. Methods : Thirty-three patients with malignant gliomas were operated and their tumor samples were examined for the chemosensitivity to 10 chosen drugs by HDRA. The most sensitive chemotherapy regimen among those pre-established was chosen based on the number of sensitive drugs or total inhibition rate (IR) of the regimen. The response was evaluated by 3 month magnetic resonance image. Results : Among 13 patients who underwent total resection of the tumor, 12 showed no evidence of disease and one patient revealed progression. The response rate in 20 patients with residual tumors was 55% (3 complete and 8 partial responses). HDRA sensitivity at the cut-off value of more than one sensitive drug in the applied regimen showed a sensitivity of 100%, specificity of 60% and predictability of 70%. Another cut-off value of >80% of total IR revealed a sensitivity of 100%, specificity of 69%, and predictability of 80%. For 12 newly diagnosed glioblastoma patients, median progression-free survival of the HDRA sensitive group was 21 months, while that of the non-sensitive group was 6 months ($p$=0.07). Conclusion : HDRA for malignant glioma was inferred as a feasible method to predict the chemotherapy response. We are encouraged to launch phase 2 clinical trial with chemosensitivity on HDRA.

Surgical management of metastatic brain tumours

Ho Shin Gwak 대한종양외과학회 2019 대한임상종양학회 학술대회지 Vol.2019 No.2

Analysis of treatment outcomes of intraventricular chemotherapy in 105 patients for leptomeningeal carcinomatosis from non-small-cell lung cancer.

Gwak, Ho-Shin,Joo, Jungnam,Kim, Sohee,Yoo, Heon,Shin, Sang Hoon,Han, Ji-Youn,Kim, Heung Tae,Lee, Jin Soo,Lee, Seung Hoon Lippincott Williams Wilkins 2013 JOURNAL OF THORACIC ONCOLOGY Vol.8 No.5

<P>Reports on the treatment result of leptomeningeal carcinomatosis (LMC) from a single primary cancer are rare and mixed treatment modalities make it even more difficult to interpret the results properly. Here, we report clinical outcomes of an intraventricular chemotherapy for LMC from non-small-cell lung cancer.</P>

Temozolomide Salvage Chemotherapy for Recurrent Anaplastic Oligodendroglioma and Oligo-Astrocytoma

Gwak, Ho-Shin,Yee, Gi Taek,Park, Chul-Kee,Kim, Jin Wook,Hong, Yong-Kil,Kang, Seok-Gu,Kim, Jeong Hoon,Seol, Ho Jun,Jung, Tae-Young,Chang, Jong Hee,Yoo, Heon,Hwang, Jeong-Hyun,Kim, Se-Hyuk,Park, Bong Ji The Korean Neurosurgical Society 2013 Journal of Korean neurosurgical society Vol.54 No.6

Objective : To evaluate the efficacy of temozolomide (TMZ) chemotherapy for recurrent anaplastic oligodendroglioma (AO) and anaplastic oligoastrocytoma (AOA). Methods : A multi-center retrospective trial enrolled seventy-two patients with histologically proven AO/AOA who underwent TMZ chemotherapy for their recurrent tumors from 2006 to 2010. TMZ was administered orally (150 to 200 $mg/m^2/day$) for 5 days per 28 days until unacceptable toxicity occurred or tumor progression was observed. Results : TMZ chemotherapy cycles administered was median 5.3 (range, 1-41). The objective response rate was 24% including 8 cases (11%) of complete response and another 23 patients (32%) were remained as stable disease. Severe side effects (${\geq}$grade 3) occurred only in 9 patients (13%). Progression-free survival (PFS) of all patients was a median 8.0 months (95% confidence interval, 6.0-10.0). The time to recurrence of a year or after was a favorable prognostic factor for PFS (p<0.05). Overall survival (OS) was apparently differed by the patient's histology, as AOA patients survived a median OS of 18.0 months while AO patients did not reach median OS at median follow-up of 11.5 months (range 2.7-65 months). Good performance status of Eastern Cooperative Oncology Group 0 and 1 showed prolonged OS (p<0.01). Conclusion : For recurrent AO/AOA after surgery followed by radiation therapy, TMZ could be recommended as a salvage therapy at the estimated efficacy equal to procarbazine, lomustine, and vincristine (PCV) chemotherapy at first relapse. For patients previously treated with PCV, TMZ is a favorable therapeutic option as 2nd line salvage chemotherapy with an acceptable toxicity rate.

Radiosurgery for Recurrent Brain Metastases after Whole-Brain Radiotherapy : Factors Affecting Radiation-Induced Neurological Dysfunction

Gwak, Ho-Shin,Yoo, Hyung-Jun,Youn, Sang-Min,Lee, Dong-Han,Kim, Mi-Sook,Rhee, Chang-Hun The Korean Neurosurgical Society 2009 Journal of Korean neurosurgical society Vol.45 No.5

Objective : We retrospectively analyzed survival, local control rate, and incidence of radiation toxicities after radiosurgery for recurrent metastatic brain lesions whose initial metastases were treated with whole-brain radiotherapy. Various radiotherapeutical indices were examined to suggest predictors of radiation-related neurological dysfunction. Methods : In 46 patients, total 100 of recurrent metastases (mean 2.2, ranged 1-10) were treated by CyberKnife radiosurgery at average dose of 23.1 Gy in 1 to 3 fractions. The median prior radiation dose was 32.7 Gy, the median time since radiation was 5.0 months, and the mean tumor volume was $12.4cm^3$. Side effects were expressed in terms of radiation therapy oncology group (RTOG) neurotoxicity criteria. Results : Mass reduction was observed in 30 patients (65%) on MRI. After the salvage treatment, one-year progression-free survival rate was 57% and median survival was 10 months. Age(<60 years) and tumor volume affected survival rate(p=0.03, each). Acute (${\leq}$1 month) toxicity was observed in 22% of patients, subacute and chronic (>6 months) toxicity occurred in 21 %, respectively. Less acute toxicity was observed with small tumors (<$10cm^3$. p=0.03), and less chronic toxicity occurred at lower cumulative doses (<100 Gy, p=0.004). "Radiation toxicity factor" (cumulative dose times tumor volume of <1,000 Gy${\times}cm^3$) was a significant predictor of both acute and chronic CNS toxicities. Conclusion: Salvage CyberKnife radiosurgery is effective for recurrent brain metastases in previously irradiated patients, but careful evaluation is advised in patients with large tumors and high cumulative radiation doses to avoid toxicity.

Tetraarsenic oxide-induced inhibition of malignant glioma cell invasion in vitro via a decrease in matrix metalloproteinase secretion and protein kinase B phosphorylation.

Gwak, Ho-Shin,Park, Myung-Jin,Park, In-Chul,Woo, Sang Hyeok,Jin, Hyeon-Ok,Rhee, Chang Hun,Jung, Hee-Won American Association of Neurological Surgeons 2014 Journal of Neurosurgery Vol.121 No.6

<P>Local invasiveness of malignant glioma is a major reason for the failure of current treatments including surgery and radiation therapy. Tetraarsenic oxide (As4O6 [TAO]) is a trivalent arsenic compound that has potential anticancer and antiangiogenic effects in selected cancer cell lines at a lower concentration than arsenic trioxide (As2O3 [ATO]), which has been more widely tested in vitro and in vivo. The authors tried to determine the cytotoxic concentration of TAO in malignant glioma cell lines and whether TAO would show anti-invasive effects under conditions independent of cell death or apoptosis.</P>

Recent Advancements of Treatment for Leptomeningeal Carcinomatosis

Gwak, Ho-Shin,Lee, Sang Hyun,Park, Weon Seo,Shin, Sang Hoon,Yoo, Heon,Lee, Seung Hoon The Korean Neurosurgical Society 2015 Journal of Korean neurosurgical society Vol.46 No.4

Treatment of Leptomeningeal carcinomatosis (LMC) from solid cancers has not advanced noticeably since the introduction of intra-cerebrospinal fluid (CSF) chemotherapy in the 1970's. The marginal survival benefit and difficulty of intrathecal chemotherapy injection has hindered its wide spread use. Even after the introduction of intraventricular chemotherapy with Ommaya reservoir, frequent development of CSF flow disturbance, manifested as increased intracranial pressure (ICP), made injected drug to be distributed unevenly and thus, the therapy became ineffective. Systemic chemotherapy for LMC has been limited as effective CSF concentration can hardly be achieved except high dose methotrexate (MTX) intravenous administration. However, the introduction of small molecular weight target inhibitors for primary cancer treatment has changed the old concept of 'blood-brain barrier' as the ultimate barrier to systemically administered drugs. Conventional oral administration achieves an effective concentration at the nanomolar level. Furthermore, many studies report that a combined treatment of target inhibitor and intra-CSF chemotherapy significantly prolongs patient survival. Ventriculolumbar perfusion (VLP) chemotherapy has sought to increase drug delivery to the subarachnoid CSF space even in patients with disturbed CSF flow. Recently authors performed phase 1 and 2 clinical trial of VLP chemotherapy with MTX, and 3/4th of patients with increased ICP got controlled ICP and the survival was prolonged. Further trials are required with newly available drugs for CSF chemotherapy. Additionally, new LMC biologic/pharmacodynamic markers for early diagnosis and monitoring of the treatment response are to be identified with the help of advanced molecular biology techniques.

Molecular Biology of Brain Metastases

( Ho-shin Gwak ) 대한뇌종양학회·대한신경종양학회·대한소아뇌종양학회 2023 Brain Tumor Research and Treatment Vol.11 No.1

Brain metastases (BMs) often occur in patients with lung cancer, breast cancer, and melanoma and are the leading cause of morbidity and mortality. The incidence of BM has increased with advanced neuroimaging and prolonged overall survival of cancer patients. With the advancement of local treatment modalities, including stereotactic radiosurgery and navigation-guided microsurgery, BM can be controlled long-term, even in cases with multiple lesions. However, radiation/chemotherapeutic agents are also toxic to the brain, usually irreversibly and cumulatively, and it remains difficult to completely cure BM. Thus, we must understand the molecular events that begin and sustain BM to develop effective targeted therapies and tools to prevent local and distant treatment failure. BM most often spreads hematogenously, and the blood-brain barrier (BBB) presents the first hurdle for disseminated tumor cells (DTCs) entering the brain parenchyma. Nevertheless, how the DTCs cross the BBB and settle on relatively infertile central nervous system tissue remains unknown. Even after successfully taking up residence in the brain, the unique tumor microenvironment is marked by restricted aerobic glycolysis metabolism and limited lymphocyte infiltration. Brain organotropism, certain phenotype of primary cancers that favors brain metastasis, may result from somatic mutation or epigenetic modulation. Recent studies revealed that exosome secretion from primary cancer or over-expression of proteolytic enzymes can “pre-condition” brain vasculoendothelial cells. The concept of the “metastatic niche,” where resident DTCs remain dormant and protected from systemic chemotherapy and antigen exposure before proliferation, is supported by clinical observation of BM in patients clearing systemic cancer and experimental evidence of the interaction between cancer cells and tumor-infiltrating lymphocytes. This review examines extant research on the metastatic cascade of BM through the molecular events that create and sustain BM to reveal clues that can assist the development of effective targeted therapies that treat established BMs and prevent BM recurrence.