Yeona Cho

Does Radiotherapy for the Primary Tumor Benefit Prostate Cancer Patients with Distant Metastasis at Initial Diagnosis

Purpose/Objectives Treatment of the primary tumor reportedly improves survival in several types of metastatic cancer. We herein evaluated the efficacy and toxicity of radiotherapy for the primary tumor in prostate cancer with metastasis. Materials/Methods The study cohort included 140 men with metastatic prostate cancer at initial diagnosis. Metastatic sites were divided into 4 groups as follows: solitary bone, 2–4 bones, ≥5 bones, and visceral organs. Patient, tumor, and treatment characteristics, and clinical outcomes were compared between patients treated with (prostate radiotherapy [PRT] group) or without radiotherapy to the primary tumor. Results Patients in PRT group presented with a statistically significantly younger age (p = .02), whereas other characteristics showed no significant difference. Overall survival (OS) and biochemical failure-free survival (BCFFS) were improved in PRT patients (3-year OS: 69% vs. 43%, p = 0.004; 3-year BCFFS: 52% vs. 16%, p = 0.002). Multivariate analysis identified PRT as a significant predictor of both OS (hazard ratio [HR] = 0.43, p = 0.015). None of the 38 PRT patients experienced severe (grade ≥3) genitourinary or gastrointestinal toxicity. Conclusions Our data suggest that radiotherapy to the primary tumor was associated with improved OS and BCFFS in metastatic prostate cancer. The results of this study warrant prospective controlled clinical trials of this approach in stage IV prostate cancer patients with limited extent of bone metastasis and good performance status.

Bladder filling variations during concurrent chemotherapy and pelvic radiotherapy in rectal cancer patients: early experience of bladder volume assessment using ultrasound scanner

Purpose To describe the early experience of analyzing variations and time trends in bladder volume of the rectal cancer patients who received bladder ultrasound scan. Materials and Methods We identified 20 consecutive rectal cancer patients who received whole pelvic radiotherapy (RT) and bladder ultrasound scan between February and April 2012. Before simulation and during the entire course of treatment, patients were scanned with portable automated ultrasonic bladder scanner, 5 times consecutively, and the median value was reported. Then a radiation oncologist contoured the bladder inner wall shown on simulation computed tomography (CT) and calculated its volume. Results Before simulation, the median bladder volume measured using simulation CT and bladder ultrasound scan was 427 mL (range, 74 to 1,172 mL) and 417 mL (range, 147 to 1,245 mL), respectively. There was strong linear correlation (R = 0.93, p < 0.001) between the two results. During the course of treatment, there were wide variations in the bladder volume and every time, measurements were below the baseline with statistical significance (12/16). At 6 weeks after RT, the median volume was reduced by 59.3% to 175 mL. Compared to the baseline, bladder volume was reduced by 38% or 161 mL on average every week for 6 weeks. Conclusion To our knowledge, this study is the first to prove that there are bladder volume variations and a reduction in bladder volume in rectal cancer patients. Moreover, our results will serve as the basis for implementation of bladder training to patients receiving RT with full bladder.

Three-dimensional analysis of patterns of locoregional recurrence after treatment in breast cancer patients: Validation of the ESTRO consensus guideline on target volume

BACKGROUND AND PURPOSE To explore the validity of the ESTRO-clinical target volume (CTV), we conducted three-dimensional analyses of locoregional recurrence (LRR) patterns according to the ESTRO- and RTOG-CTVs. Moreover, we explored which factors contribute to metastasis development outside the recommended CTV. MATERIALS AND METHODS We identified patients with post-treatment LRR explicitly exhibited on computed tomography (CT) images. All recurrences on CT were overlaid on representative CT images at the equivalent location, based on reference anatomic structures. RESULTS A total of 235 recurrent lesions were identified in 129 patients. We depicted all LRR patterns in relation to the ESTRO- and RTOG-CTVs on CT and maximum intensity projection images. The ESTRO-CTV successfully contained the extent of the LRR within the RTOG-CTV in 96.4% of all early-stage breast-conserved women. Geographic misses of local recurrence were frequently observed in mastectomy patients (P=.002) and tended to originate from deep, but thin, chest walls. The rate of geographic misses of regional recurrence was low (3.6%) at the early stage, but increased in patients aged <45years and with triple-negative tumors (P<.05). CONCLUSIONS Application of the ESTRO-CTV in early-stage disease seems justified.

Treatment outcome of radiation therapy and concurrent targeted molecular therapy in spinal metastasis from renal cell carcinoma

Purpose: To evaluate the clinical outcomes of patients who underwent radiation therapy with or without targeted molecular therapy for the treatment of spinal metastasis from renal cell carcinoma (RCC). Materials and Methods: A total of 28 spinal metastatic lesions from RCC patients treated with radiotherapy between June 2009 and June 2015 were retrospectively reviewed. Thirteen lesions were treated concurrently with targeted molecular therapy (concurrent group) and 15 lesions were not (nonconcurrent group). Local control was defined as lack of radiographically evident local progression and neurological deterioration. Results: At a median follow-up of 11 months (range, 2 to 58 months), the 1-year local progression-free rate (LPFR) was 67.0%. The patients with concurrent targeted molecular therapy showed significantly higher LPFR than those without (p = 0.019). After multivariate analysis, use of concurrent targeted molecular therapy showed a tendency towards improved LPFR (hazard ratio, 0.13; 95% confidence interval, 0.01 to 1.16). There was no difference in the incidence of systemic progression between concurrent and nonconcurrent groups. No grade ≥2 toxicities were observed during or after radiotherapy. Conclusion: Our study suggests the possibility that concurrent use of targeted molecular therapy during radiotherapy may improve LPFR. Further study with a large population is required to confirm these results.

Predictive factors of symptomatic radiation pneumonitis in primary and metastatic lung tumors treated with stereotactic ablative body radiotherapy

Purpose Although stereotactic ablative body radiotherapy (SABR) is widely used therapeutic technique, predictive factors of radiation pneumonitis (RP) after SABR remain undefined. We aimed to investigate the predictive factors affecting RP in patients with primary or metastatic lung tumors who received SABR. Materials and Methods From 2012 to 2015, we reviewed 59 patients with 72 primary or metastatic lung tumors treated with SABR, and performed analyses of clinical and dosimetric variables related to symptomatic RP. SABR was delivered as 45–60 Gy in 3–4 fractions, which were over 100 Gy in BED when the α/β value was assumed to be 10. Tumor volume and other various dose volume factors were analyzed using median value as a cutoff value. RP was graded per the Common Terminology Criteria for Adverse Events v4.03. Results At the median follow-up period of 11 months, symptomatic RP was observed in 13 lesions (12 patients, 18.1%), including grade 2 RP in 11 lesions and grade 3 in 2 lesions. Patients with planning target volume (PTV) of ≤14.35 mL had significantly lower rates of symptomatic RP when compared to others (8.6% vs. 27%; p = 0.048). Rates of symptomatic RP in patients with internal gross tumor volume (iGTV) >4.21 mL were higher than with ≤4.21 mL (29.7% vs. 6.1%; p = 0.017). conclusions The incidence of symptomatic RP following treatment with SABR was acceptable with grade 2 RP being observed in most patients. iGTV over 4.21 mL and PTV of over 14.35 mL were significant predictive factors related to symptomatic RP.

OC-0538: Tumor-related leukocytosis associated with poor radiation response and outcome in cervical cancer

Results: Median follow up time was 5.3 years. No differences were observed in clinicopathological factors based on p16 status. p16 was positive, intermediate and negative in 45 (31%), 21 (15%) and 77 (54%) of cases, respectively. No highrisk HPV subtypes were identified, irrespective of p16 status. p16 status was not prognostic for overall (HR 1.08 95% CI [0.85 1.36], p=0.528), cancer-specific (HR 1.12 95% CI [0.77 1.64], p=0.542) or progression-free survival (HR 1.03 95% CI [0.83 1.29], p=0.783). Distant metastasis free survival, freedom from locoregional failure and freedom from local failure were also not significantly associated with p16 status.

Morphologic change of rectosigmoid colon using belly board and distended bladder protocol

Purpose This study investigates morphologic change of the rectosigmoid colon using a belly board in prone position and distended bladder in patients with rectal cancer. We evaluate the possibility of excluding the proximal margin of anastomosis from the radiation field by straightening the rectosigmoid colon. Materials and Methods Nineteen patients who received preoperative radiotherapy between 2006 and 2009 underwent simulation in a prone position (group A). These patients were compared to 19 patients treated using a belly board in prone position and a distended bladder protocol (group B). Rectosigmoid colon in the pelvic cavity was delineated on planning computed tomography (CT) images. A total dose of 45 Gy was planned for the whole pelvic field with superior margin of the sacral promontory. The volume and redundancy of rectosigmoid colon was assessed. Results Patients in group B had straighter rectosigmoid colons than those in group A (no redundancy; group A vs. group B, 10% vs. 42%; p = 0.03). The volume of rectosigmoid colon in the radiation field was significantly larger in group A (56.7 vs. 49.1 mL; p = 0.009). In dose volume histogram analysis, the mean irradiated volume was lower in patients in group B (V45 27.2 vs. 18.2 mL; p = 0.004). In Pearson correlation coefficient analysis, the in-field volume of rectosigmoid colon was significantly correlated with the bladder volume (R = 0.86, p = 0.003). Conclusion Use of a belly board and distended bladder protocol could contribute to exclusion of the proximal margin of anastomosis from the radiation field.

Kilovoltage radiotherapy for companion animals: dosimetric comparison of 300 kV, 450 kV, and 6 MV X-ray beams

Radiotherapy for the treatment of cancer in companion animals is currently administered by using megavoltage X-ray machines. Because these machines are expensive, most animal hospitals do not perform radiotherapy. This study evaluated the ability of relatively inexpensive kilovoltage X-ray machines to treat companion animals. A simulation study based on a commercial treatment-planning system was performed for tumors of the brain (non-infectious meningoencephalitis), nasal cavity (malignant nasal tumors), forefoot (malignant muscular tumors), and abdomen (malignant intestinal tumors). The results of kilovoltage (300 kV and 450 kV) and megavoltage (6 MV) X-ray beams were compared. Whereas the 300 kV and 6 MV X-ray beams provided optimal radiation dose homogeneity and conformity, respectively, for brain tumors, the 6 MV X-rays provided optimal homogeneity and radiation conformity for nasal cavity, forefoot, and abdominal tumors. Although megavoltage X-ray beams provided better radiation dose distribution in most treated animals, the differences between megavoltage and kilovoltage X-ray beams were relatively small. The similar therapeutic effects of the kilovoltage and 6 MV X-ray beams suggest that kilovoltage X-ray beams may be effective alternatives to megavoltage X-ray beams in treating cancers in companion animals.

Individual case review in a phase 3 randomized trial to investigate the role of internal mammary lymph node irradiation for breast cancer: Korean Radiation Oncology Group 08-06 study

PURPOSE/OBJECTIVE This study aimed to assess protocol compliance based on an individual case review (ICR) of the Korean Radiation Oncology Group-0806 trial. METHODS AND MATERIALS For the ICR, 747 participants were divided into eight subgroups based on internal mammary node irradiation (IMNI), tumor laterality, and surgery type. Next, 15% of patients were randomly selected within each subgroup, and corresponding hospitals were subsequently requested to upload information related to radiation therapy (RT) planning. We reviewed the dose distributions of targets and organs at risk to determine protocol compliance. RESULTS Data of 102 patients were collected. Overall, RT plans were found to be mostly protocol-compliant, with acceptability rates of 60-80% despite deviations in the ipsilateral lung in Arm 2 (IMNI group). However, despite few deviations, a subgroup analysis revealed significant differences in protocol compliance. Among RT techniques, plans using standard and partial wide tangents were most compliant in both Arms. In this ICR, the estimated survival benefits based on IMN doses were 7.7%, 8.4%, and 7.2% for all, breast-conserving surgery, and mastectomy cases, respectively. CONCLUSION This ICR demonstrated overall protocol compliance, despite significant differences with regard to IMN irradiation and organs at risk according to subgroups and adopted field arrangements.

Ruthenium-106 Brachytherapy with or without Additional Local Therapy Shows Favorable Outcome for Variable-Sized Choroidal Melanomas in Korean Patients

Purpose The purpose of this study was to report clinical outcomes of ruthenium-106 (106Ru) brachytherapy with or without additional local therapy for choroidal melanomas in Korean patients. Materials and Methods A total of 88 patients diagnosed with choroidal melanomas were treated with 106Ru brachytherapy between 2006 and 2012. Patients were divided into two groups according to their tumor height: a large group (≥ 6 mm, n=50) and a small group (< 6 mm, n=38). Most patients in the large group received combined therapy with local excision and/or transpupillary thermotherapy. In general, 85-95 Gy was administered to the apex of the tumor, while 100 Gy was administered to the point 2-6 mm from the outer surface of the sclera for patients undergoing combined therapy. Results The median follow-up duration was 30 months. The 3-year local control rate was significantly higher in the small group than in the large group (94% vs. 70%, p=0.047). The free from distant metastasis (FFDM) rate and the overall survival (OS) rate were also higher in patients in the small group (3-year FFDM, 97% vs. 76%; p=0.031 and 3-year OS, 97% vs. 72%; p=0.036). A total of 13 patients underwent enucleation. The eye-preservation rate was also higher in the small group (3-year eye-preservation rate, 94% vs. 70%; p=0.050), and tumor height was a significant prognostic factor for eye-preservation. Conclusion 106Ru brachytherapy showed favorable outcomes in small choroidal melanomas in Korean patients. Although additional local treatment could improve eye-preservation rate for large tumors, other strategies should be considered for disease control.