Sei-Chul Yoon

Fractionated stereotactic radiotherapy as reirradiation for locally recurrent head and neck cancer.

PURPOSE We report early preliminary experience with CyberKnife radiosurgery (RS) as salvage treatment for locally recurrent head and neck cancer (HNC). METHODS AND MATERIALS Between March 2004 and August 2006, 36 patients (44 sites) were treated with CyberKnife RS as reirradiation for locally recurrent HNC. Treatment sites were as follows: nasopharynx (8), maxillary sinus (8), neck lymph nodes (8), skull base (7), nasal cavity (4), retropharyngeal lymph nodes (3), orbit (2), and others (4). Total doses administered were 18-40 Gy (median, 30 Gy) in 3 to 5 fractions to the 65%-85% isodose line for 3-5 consecutive days. Previous external radiation dose ranged from 39.6 to 134.4 Gy (median, 70.2 Gy). Gross tumor volume ranged from 0.2 to 114.9 cm(3) (median, 22.6 cm(3)). Median follow-up was 17.3 months. RESULTS Thirty-five of 44 sites were evaluated for response. Fifteen (42.9%) sites achieved complete response, 13 sites (37.1%) achieved a partial response, 3 (8.6%) sites maintained stable disease, and 4 sites (11.4%) showed tumor progression. Grade III acute complications were noted in 13 patients. Late complications were observed in three patients (1 bone necrosis, 2 soft tissue necrosis) during follow-up. CONCLUSION These preliminary results suggest that fractionated stereotactic radiosurgery is an effective treatment modality as a salvage treatment with good short-term local control. The early overall response rate is encouraging. However, more experience and a longer follow-up are necessary to determine the role of fractionated stereotactic radiosurgery as a salvage treatment of locally recurrent HNC and to define long-term complications.

The TGF-β1 dynamics during radiation therapy and its correlation to symptomatic radiation pneumonitis in lung cancer patients

BackgroudThe underlying molecular and cellular mechanisms of radiation pneumonitis (RP) are very complex. Several biological factors need to be considered together with the well known dosimetric parameters for understanding the molecular events in developing RP in lung cancer patients. The aim of this study was to correlate the variations of the cytokine levels in lung cancer patients during radiation therapy (RT) with the occurrence of symptomatic RP.MethodsThirty-four lung cancer patients who received three-dimensional conformal radiation therapy were evaluated prospectively. Serial blood samples before, at the beginning, in the middle of, at the end of RT and 2 and 4 weeks after RT were analyzed for IL-1α, IL-6, IL-10, TNF-α and TGF-β1 by performing enzyme-linked immunosorbent assay. The predictive values of dosimetric factors for RP were evaluated, too.ResultsOverall, 8 patients (23.5%) had grade ≥ 2 RP. By serial measurement of cytokines level, only the TGF-β1 level showed a correlation to the symptomatic RP. None of the other cytokines, IL-1α, IL-6, IL-10 and TNF-α level was correlated with the risk of RP. The mean pretreatment TGF-β1 level did not differ between RP and non-RP groups. However, during the period of radiation treatment, the TGF-β1 level began to increase at the end of RT in the RP group and became significantly higher 4 weeks after RT (p = 0.007). Using an ANOVA model for repeated-measures, we found significant associations between the changes of TGF-β1 during the time course of the RT and the risk of developing RP (p < 0.001). Most of the dosimetric factors showed a significant association with RP.ConclusionOur results show that the changes of TGF-β1 could be correlated with RP and the incorporation of the biological parameters into the dosimetric data could be useful for predicting symptomatic RP.

ERCC1 (excision repair cross-complementation group 1) expression as a predictor for response of neoadjuvant chemotherapy for FIGO stage 2B uterine cervix cancer.

OBJECTIVE Platinum-based neoadjuvant chemotherapy for locally advanced cervical cancer has some benefits for patients responding to chemotherapy. However, no validated clinical or biologic predictor of response to this chemotherapy has been identified to date. METHODS We employ immunohistochemical analysis to determine the expression patterns of the excision repair cross-complementation group1 (ERCC1) protein in pre-treatment cervical biopsy tissue. In total, 43 stage IIB patients had been enrolled in a previous etoposide and cisplatin neoadjuvant phase II clinical trial, allowing comparison of the effects of cisplatin-based neoadjuvant chemotherapy on response in relation to ERCC1 expression. RESULTS Among the 43 patients studied, 34 (79.1%) were positive and 9 (20.9%) were negative for ERCC1. Response to chemotherapy (according to RECIST criteria) was observed in all patients with negative ERCC1 expression. In logistic regression analysis, ERCC1 negativity continued to be an independent predictor for responsiveness to neoadjuvant chemotherapy (p=0.021). Among the pretreatment factors, low ERCC1 expression was a significant prognostic factor of disease-free survival in multivariate analysis (p=0.046). CONCLUSIONS The ERCC1 expression patterns in pretreatment specimens may thus facilitate the prediction of responses to cisplatin-based NAC. We propose that patients expressing low levels of ERCC1 derive the most benefit from cisplatin-based NAC.

The relevance of serum carcinoembryonic antigen as an indicator of brain metastasis detection in advanced non-small cell lung cancer

Although many biomarkers have emerged in non-small cell lung cancer (NSCLC), the predictive value of site-specific spread is not fully defined. We designed this study to determine if there is an association between serum biomarkers and brain metastasis in advanced NSCLC. We evaluated 227 eligible advanced NSCLC patients between May 2005 and March 2010. Patients who had been newly diagnosed with stage IV NSCLC but had not received treatment previously, and had available information on at least one of the following pretreatment serum biomarkers were enrolled: carcinoembryonic antigen (CEA), cytokeratin 19 fragments (CYFRA 21-1), cancer antigen 125 (CA 125), cancer antigen 19-9, and squamous cancer cell antigen. Whole body imaging studies and magnetic resonance imaging of the brain were reviewed, and the total number of metastatic regions was scored. Brain metastasis was detected in 66 (29.1%) patients. Although serum CEA, CYFRA 21-1, and CA 125 levels were significantly different between low total metastatic score group (score 1–3) and high total metastatic score group (score 4–7), only CEA level was significantly different between patients with brain metastasis and those without brain metastasis (p < 0.0001). The area under the receiver operating curve of serum CEA for the prediction of brain metastasis was 0.724 (p = 0.0001). The present study demonstrated that the pretreatment serum CEA level was significantly correlated with brain metastasis in advanced NSCLC. These findings suggested the possible role of CEA in the pathogenesis of brain invasion. More vigilant surveillance would be warranted in the high-risk group of patients with high serum CEA level and multiple synchronous metastasis.

Radiation Therapy Combined with (or without) Cisplatin-based Chemotherapy for Patients with Nasopharyngeal Cancer: 15-years Experience of a Single Institution in Korea

PURPOSE This retrospective study was carried out to evaluate the efficacy and toxicity of radiation therapy (RT) with/without cisplatin-based chemotherapy in nasopharyngeal cancer (NPC). MATERIALS AND METHODS One hundred forty six patients with NPC received curative RT and/or cisplatin-based chemotherapy. Thirty-nine patients were treated with induction chemotherapy (IC), including cisplatin and 5-fluorouracil followed by RT. Another 63 patients were treated with concurrent chemoradiotherapy (CCRT) using cisplatin, and 22 patients were treated with IC followed by CCRT. The remaining 22 patients were treated with RT alone. RESULTS One hundred four (80.0%) patients achieved complete response (CR), and 23 (17.7%) patients achieved partial response (PR). The patterns of failure were: locoregional recurrences in 21.2% and distant metastases in 17.1%. Five-year overall survival (OS) and progression free survival (PFS) were 50.7% and 45.0%, respectively. Multivariate Cox stepwise regression analysis revealed CR to chemoradiotherapy to be a powerful prognostic factor for OS. CR to chemoradiotherapy and completion of radiation according to the time schedule were favorable prognostic factors for PFS. A comparison of each treatment group (IC --> RT vs. CCRT vs. IC --> CCRT vs. RT alone) revealed no significant differences in the OS or PFS. However, subgroup analysis showed significant differences in both OS and DFS in favor of the combined chemoradiotherapy group compared with RT alone, for stage IV and T3-4 tumors. Grade 3-4 toxicities were more common in the combined chemoradiotherapy arm, particularly in the CCRT group. CONCLUSIONS This study was limited in that it was a retrospective study, much time was required to collect patients, and there were imbalances in the number of patients in each treatment group. Combined chemoradiotherapy remarkably prolonged the OS and PFS in subgroup patients with stage IV or T3-4 NPC.

Long-Term Follow-Up of Preoperative Pelvic Radiation Therapy and Concomitant Boost Irradiation in Locally Advanced Rectal Cancer Patients: A Multi-Institutional Phase II Study (KROG 04-01)

PURPOSE To perform a prospective phase II study to investigate the efficacy and safety of preoperative pelvic radiation therapy and concomitant small-field boost irradiation with 5-fluorouracil and leucovorin for 5 weeks in locally advanced rectal cancer patients. METHODS AND MATERIALS Sixty-nine patients with locally advanced, nonmetastatic, mid-to-lower rectal cancer were prospectively enrolled. They had received preoperative chemoradiation therapy and total mesorectal excision. Pelvic radiation therapy of 43.2 Gy in 24 fractions plus concomitant boost radiation therapy of 7.2 Gy in 12 fractions was delivered to the pelvis and tumor bed for 5 weeks. Two cycles of 5-fluorouracil and leucovorin were administered for 3 days in the first and fifth week of radiation therapy. The pathologic response, survival outcome, and treatment toxicity were evaluated for the study endpoints. RESULTS Of 69 patients, 8 (11.6%) had a pathologically complete response. Downstaging rates were 40.5% for T classification and 68.1% for N classification. At the median follow-up of 69 months, 36 patients have been followed up for more than 5 years. The 5-year disease-free survival (DFS) and overall survival rates were 66.0% and 75.3%, respectively. Higher pathologic T (P=.045) and N (P=.032) classification were significant adverse prognostic factors for DFS, and high-grade histology was an adverse prognostic factor for both DFS (P=.025) and overall survival (P=.031) on the multivariate analysis. Fifteen patients (21.7%) experienced grade 3 or 4 acute toxicity, and 7 patients (10.1%) had long-term toxicity. CONCLUSION Preoperative pelvic radiation therapy with concomitant boost irradiation with 5-fluorouracil and leucovorin for 5 weeks showed acceptable acute and long-term toxicities. However, the benefit of concomitant small-field boost irradiation for 5 weeks in rectal cancer patients was not demonstrated beyond conventional irradiation for 6 weeks in terms of tumor response and survival.

Outcomes and prognostic factors of cervical cancer after concurrent chemoradiation.

Aim:  Concurrent chemoradiation (CCRT) is the standard treatment for locally advanced cervical cancer. This study was undertaken to evaluate the outcomes and the prognostic factors for cervical cancer after CCRT.

Radiation-induced brain injury: retrospective analysis of twelve pathologically proven cases.

Purpose This study was designed to determine the influencing factors and clinical course of pathologically proven cases of radiation-induced brain injury (RIBI). Materials and Methods The pathologic records of twelve patients were reviewed; these patients underwent surgery following radiotherapy due to disease progression found by follow-up imaging. However, they were finally diagnosed with RIBI. All patients had been treated with 3-dimensional conventional fractionated radiotherapy and/or radiosurgery for primary or metastatic brain tumors with or without chemotherapy. The histological distribution was as follows: two falx meningioma, six glioblastoma multiform (GBM), two anaplastic oligodendroglioma, one low grade oligodendroglioma, and one small cell lung cancer with brain metastasis. Results Radiation necrosis was noted in eight patients and the remaining four were diagnosed with radiation change. Gender (p = 0.061) and biologically equivalent dose (BED)3 (p = 0.084) were the only marginally influencing factors of radiation necrosis. Median time to RIBI was 7.3 months (range, 0.5 to 61 months). Three prolonged survivors with GBM were observed. In the subgroup analysis of high grade gliomas, RIBI that developed <6 months after radiotherapy was associated with inferior overall survival rates compared to cases of RIBI that occurred ≥6 months (p = 0.085). Conclusion Our study demonstrated that RIBI could occur in early periods after conventional fractionated brain radiotherapy within normal tolerable dose ranges. Studies with a larger number of patients are required to identify the strong influencing factors for RIBI development.

Treatment outcome in patients with vulvar cancer: comparison of concurrent radiotherapy to postoperative radiotherapy

Purpose To evaluate outcome and morbidity in patients with vulvar cancer treated with radiotherapy, concurrent chemoradiotherapy or postoperative radiotherapy. Materials and Methods The records of 24 patients treated with radiotherapy for vulvar cancer between July 1993 and September 2009 were retrospectively reviewed. All patients received once daily 1.8-4 Gy fractions external beam radiotherapy to median 51.2 Gy (range, 19.8 to 81.6 Gy) on pelvis and inguinal nodes. Seven patients were treated with primary concurrent chemoradiotherapy, one patient was treated with primary radiotherapy alone, four patients received palliative radiotherapy, and twelve patients were treated with postoperative radiotherapy. Results Twenty patients were eligible for response evaluation. Response rate was 55% (11/20). The 5-year disease free survival was 42.2% and 5-year overall survival was 46.2%, respectively. Fifty percent (12/24) experienced with acute skin complications of grade III or more during radiotherapy. Late complications were found in 8 patients. 50% (6/12) of patients treated with lymph node dissection experienced severe late complications. One patient died of sepsis from lymphedema. However, only 16.6% (2/12) of patients treated with primary radiotherapy developed late complications. Conclusion Outcome of patients with vulvar cancer treated with radiotherapy showed relatively good local control and low recurrence. Severe late toxicities remained higher in patients treated with both node dissection and radiotherapy.

Measurements of the Relative Output Factors for Radiosurgical CyberKnife Collimators Using a Glass Rod Dosimeter

The purpose of this study was to evaluate the accuracy of a glass rod dosimeter (GRD) for relative output factor measurements in the CyberKnife radiosurgery system. The output factors measured with the GRD were compared to those obtained with an ionization chamber, a diode and a Gafchromic film. The GRD was irradiated in a water phantom using an in-house custom designed holder stand. The relative output factors measured with the four dosimeters showed very similar results for collimator diameters larger than 20 mm. The mean value of the output factors of the GRD for the 5 mm collimator was 0.695. The output factor measured with the ionization chamber was approximately 13.7% lower than the corresponding GRD values for the 5 mm collimator. The diode output factors were 3.1% and 1.9% higher than the GRD for the 5 mm and 7.5 mm collimators, respectively. However, the GRD results were in agreement with the measurements obtained with a Gafchromic film for all of the collimator diameters.