Dae Sik Yang

Effectiveness of High-dose Three-dimensional Conformal Radiotherapy in Hepatocellular Carcinoma with Portal Vein Thrombosis

OBJECTIVEnTo evaluate the treatment outcome of three-dimensional conformal radiotherapy in hepatocellular carcinoma patients with portal vein thrombosis, concerning survival and treatment response of thrombosis.nnnMETHODSnForty-five patients with hepatocellular carcinoma who had portal vein thrombosis treated from March 2005 to March 2011 were the subjects of this study. The median total dose was 61.2 Gy (range 38-65 Gy). A daily radiation dose of 1.8-2.5 Gy was administered at a frequency of five fractions per week. The clinical target volume included portal vein thrombosis with or without primary tumour with clinical consideration.nnnRESULTSnThree of the 45 patients (6.7%) showed complete remission of portal vein thrombosis, 25 patients (55.6%) showed partial response, 14 patients (31%) had stable disease and 3 patients (6.7%) had progressive disease. The median and the 1-year survival rate of the responders (complete remission + progressive disease) were 16.7 months and 63.7%, respectively, and those of the non-responders were 8 months and 28.2%, respectively (P= 0.003). A univariate analysis revealed that thrombosis response, Eastern Cooperative Oncology Group performance status, maximum tumour size, tumour bilaterality, Cancer of the Liver Italian Program stage, Okuda stage, hepatic arterial infusion, hepatitis B e antigen and hepatitis C antibody were statistically significant prognostic factors affecting survival. In a multivariate analysis, thrombosis response, Cancer of the Liver Italian Program stage and Okuda stage were found to be statistically significant. No clinically significant radiation-induced liver disease was noted. One grade 3 late complication (duodenal ulcer) was reported.nnnCONCLUSIONSnHigh-dose three-dimensional conformal radiotherapy yielded a response rate of 62.3%. It is a safe and effective treatment prolonging the survival of hepatocellular carcinoma patients with portal vein thrombosis.

Radiotherapy for pituitary adenomas: long-term outcome and complications

Purpose To evaluate long-term local control rate and toxicity in patients treated with external beam radiotherapy (EBRT) for pituitary adenomas. Materials and Methods We retrospectively reviewed the medical records of 60 patients treated with EBRT for pituitary adenoma at Korea University Medical Center from 1996 and 2006. Thirty-five patients had hormone secreting tumors, 25 patients had non-secreting tumors. Fifty-seven patients had received postoperative radiotherapy (RT), and 3 had received RT alone. Median total dose was 54 Gy (range, 36 to 61.2 Gy). The definition of tumor progression were as follows: evidence of tumor progression on computed tomography or magnetic resonance imaging, worsening of clinical sign requiring additional operation or others, rising serum hormone level against a previously stable or falling value, and failure of controlling serum hormone level so that the hormone level had been far from optimal range until last follow-up. Age, sex, hormone secretion, tumor extension, tumor size, and radiation dose were analyzed for prognostic significance in tumor control. Results Median follow-up was 5.7 years (range, 2 to 14.4 years). The 10-year actuarial local control rates for non-secreting and secreting adenomas were 96% and 66%, respectively. In univariate analysis, hormone secretion was significant prognostic factor (p = 0.042) and cavernous sinus extension was marginally significant factor (p = 0.054) for adverse local control. All other factors were not significant. In multivariate analysis, hormone secretion and gender were significant. Fifty-three patients had mass-effect symptoms (headache, dizziness, visual disturbance, hypopituitarism, loss of consciousness, and cranial nerve palsy). A total of 17 of 23 patients with headache and 27 of 34 patients with visual impairment were improved. Twenty-seven patients experienced symptoms of endocrine hypersecretion (galactorrhea, amenorrhea, irregular menstruation, decreased libido, gynecomastia, acromegaly, and Cushings disease). Amenorrhea was abated in 7 of 10 patients, galactorrhea in 8 of 8 patients, acromegaly in 7 of 11 patients, Cushings disease in 4 of 4 patients. Long-term complication was observed in 4 patients; 3 patients with cerebrovascular accident, 1 patient developed dementia. Of these patients, 3 of 4 received more than 60 Gy of irradiation. Conclusion EBRT is highly effective in preventing recurrence and reducing mass effect of non-secreting adenoma. Effort to improve tumor control of secreting adenoma is required. Careful long-term follow-up is required when relatively high dose is applied. Modern radiosurgery or proton RT may be options to decrease late complications.

Set-up uncertainty during breast radiotherapy

PurposeThe aim of this work was to establish a customized strategy for image-guided radiotherapy during whole breast irradiation. Risk factors associated with extensive errors were assessed.Methods and materialsA series of 176xa0consecutive breasts in 174xa0patients were retrospectively assessed. Electronic portal images from 914xa0medial and 807xa0lateral directions were reviewed. On the basis of the chest wall, the deviations between the simulation and each treatment were measured. The systematic (Σ) and random error (σ) of population, and the planning target volume (PTV) margin (2u2009Σu2009+u20090.7σ) were calculated for each direction. Extensive set-up errors were defined as the fraction over the PTV margins in any direction. For extensive set-up errors, χ2 tests and logistic regression analyses were conducted.ResultsThe medial and lateral PTV margins for the right–left, superior–inferior, and anterior–posterior axes and the rotation of collimator were 2.6 and 2.4xa0mm, 4.6 and 4.6xa0mm, and 3.1 and 3.3xa0mm and 2.8 and 2.9u2009° and cut-off values for extensive errors were 3, 5, and 4xa0mm and 3u2009°, respectively. In χ2 tests, tumor in upper outer quadrant (pu2009=u20090.012) and chest wall thickness ≥u20092.0xa0cm (pu2009=u20090.003) for medial portals and age group (pu2009=u20090.036) for lateral portals were associated with extensive errors. In multivariate tests, the extensive error on the initial fraction had a high probability of extensive set-up errors in both medial (ORu2009=u20094.26, pu2009<u20090.001) and lateral portals (ORu2009=u20093.07, pu2009<u20090.001).ConclusionIn terms of the set-up uncertainty during breast irradiation, patients with extensive error in the initial treatment should be closely observed with serial image-guided radiotherapy.ZusammenfassungZielDas Ziel der Studie war es, eine kundenspezifische Strategie für die bildgesteuerte Radiotherapie während der Bestrahlung der gesamten Brust zu entwickeln. Risikofaktoren und damit assoziierte weitreichende Fehler wurden ermittelt.Patienten und MethodenEine Serie von 176xa0Brüsten von insgesamt 174xa0Patienten wurde retrospektiv bewertet. Elektronische Portalbilder aus 914 medialen und 807 lateralen Richtungen wurden geprüft. Basierend auf der Brustwand wurden die Abweichungen zwischen der Simulation und jeder Behandlung gemessen. Für jede Richtung wurde der systematische (Σ) und der zufällige Fehler (σ) der Bevölkerungsgruppe sowie die Grenze (2Σu2009+u20090,7σ) des geplanten Zielvolumens (PTV) berechnet. Umfangreiche Set-up-Fehler wurden als Fraktion definiert, welche die PTV-Grenzen in jede Richtung überschreitet. Für weitreichende Set-up-Fehler wurden χ2-Tests und logistische Regressionsanalysen durchgeführt.ErgebnisseDie medialen und lateralen PTV-Grenzen für die rechten-linken, superioren-inferioren und anterioren-posterioren Achsen und die Rotation des Kollimators waren jeweils 2,6 und 2,4xa0mm, 4,6 und 4,6xa0mm, 3,1 und 3,3xa0mm sowie 2,8 und 2,9u2009°. Cut-off-Werte für weitreichende Fehler waren jeweils 3, 5 und 4xa0mm bzw. 3u2009°. In den χ2-Tests waren für mediale Portale ein Tumor am oberen äußeren Quadranten (pu2009=u20090,012) und die Brustwanddicke ≥u20092,0xa0cm (pu2009=u20090,003) sowie für laterale Portale die Altersgruppe (pu2009=u20090,036) mit den weitreichenden Fehlern verbunden. In den multivariaten Tests war ein weitreichender Fehler bei der anfänglichen Fraktion mit einer hohen Wahrscheinlichkeit für umfangreiche Set-up-Fehler in beiden medialen (ORu2009=u20094,26; pu2009<u20090,001) und lateralen Portalen (ORu2009=u20093,07; pu2009<u20090,001) verbunden.SchlussfolerungIm Hinblick auf die Set-up-Unsicherheit bei der Brustbestrahlung sollten Patienten mit weitreichenden Fehlern während der anfänglichen Behandlung durch serielle bildgesteuerte Radiotherapie genauer beobachtet werden.

Treatment outcome of conservative surgery plus postoperative radiotherapy for extremity soft tissue sarcoma

Purpose To evaluate the treatment outcome and prognostic factor of postoperative radiotherapy for extremity soft tissue sarcoma (STS). Materials and Methods Forty three patients with extremity STS were treated with conservative surgery and postoperative radiotherapy from January 1981 to December 2010 at Korea University Medical Center. Median total 60 Gy (range, 50 to 74.4 Gy) of radiation was delivered and 7 patients were treated with chemotherapy. Results The median follow-up period was 70 months (range, 5 to 302 months). Twelve patients (27.9%) sustained relapse of their disease. Local recurrence occurred in 3 patients (7.0%) and distant metastases developed in 10 patients (23.3%). The 5-year overall survival (OS) was 69.2% and disease free survival was 67.9%. The 5-year local relapse-free survival was 90.7% and distant relapse-free survival was 73.3%. On univariate analysis, no significant prognostic factors were associated with development of local recurrence. Histologic grade (p = 0.005) and stage (p = 0.02) influenced the development of distant metastases. Histologic grade was unique significant prognostic factor for the OS on univariate and multivariate analysis. Severe acute treatment-related complications, Common Terminology Criteria for Adverse Events (CTCAE) grade 3 or 4, developed in 6 patients (14.0%) and severe late complications in 2 patients (4.7%). Conclusion Conservative surgery with postoperative radiotherapy achieved a satisfactory rate of local control with acceptable complication rate in extremity STS. Most failures were distant metastases that correlate with tumor grade and stage. The majority of local recurrences developed within the field. Selective dose escalation of radiotherapy or development of effective systemic treatment might be considered.

Whole breast irradiation for small-sized breasts after conserving surgery: is the field-in-field technique optimal?

BackgroundTo determine the optimal whole breast irradiation technique in patients with small-sized breasts, tangential and field-in-field IMRT (FIF) techniques were compared.MethodsSixteen patients with ≤3xa0cm breast height and ≤350xa0cc volume were included. Seven patients had 4D CTs performed. The planning target volumes (PTV), editing 5 and 2xa0mm from the surface on the whole breast, were delineated and called PTV(5) and PTV(2), respectively. Dose–volume histograms of tangential techniques with open beam (OT) and wedge filter (WT), conventional FIF (cFIF), and modified FIF (mFIF) blocking out the lung were produced. Various dose–volume parameters, the dose heterogeneity index (DHtrI), dose homogeneity index (DHmI), and PTV dose improvement (PDI) were calculated.ResultsOT compared with WT showed a significantly favorable V90 of the heart and lung, and PTV(5)-dose distribution. Comparing OT and cFIF, OT showed significant improvement in the V95 of PTV(2), whereas cFIF showed significant improvement in the V95, DHtrI, DHmI, and PDI of the PTV(5). In comparing cFIF and mFIF, mFIF showed improved dose distributions of the heart and lung, while cFIF presented the better V95, DHtrI, DHmI, and PDI of the PTV(5). Respiratory influences on the absolute dose were mostly within 1xa0%. The ratio of free breathing and each respiratory phase was similar among OT, cFIF, and mFIF.ConclusionscFIF has favorable dose conformity and is suggested to be an optimal method for small-sized breasts. However, OT for dose coverage close to the skin and mFIF for normal tissue may also be potential alternatives. Respiratory effects are minimal.

Set-up uncertainty during breast radiotherapySet-up-Unsicherheit während der Brustbestrahlung

PurposeThe aim of this work was to establish a customized strategy for image-guided radiotherapy during whole breast irradiation. Risk factors associated with extensive errors were assessed.Methods and materialsA series of 176xa0consecutive breasts in 174xa0patients were retrospectively assessed. Electronic portal images from 914xa0medial and 807xa0lateral directions were reviewed. On the basis of the chest wall, the deviations between the simulation and each treatment were measured. The systematic (Σ) and random error (σ) of population, and the planning target volume (PTV) margin (2u2009Σu2009+u20090.7σ) were calculated for each direction. Extensive set-up errors were defined as the fraction over the PTV margins in any direction. For extensive set-up errors, χ2 tests and logistic regression analyses were conducted.ResultsThe medial and lateral PTV margins for the right–left, superior–inferior, and anterior–posterior axes and the rotation of collimator were 2.6 and 2.4xa0mm, 4.6 and 4.6xa0mm, and 3.1 and 3.3xa0mm and 2.8 and 2.9u2009° and cut-off values for extensive errors were 3, 5, and 4xa0mm and 3u2009°, respectively. In χ2 tests, tumor in upper outer quadrant (pu2009=u20090.012) and chest wall thickness ≥u20092.0xa0cm (pu2009=u20090.003) for medial portals and age group (pu2009=u20090.036) for lateral portals were associated with extensive errors. In multivariate tests, the extensive error on the initial fraction had a high probability of extensive set-up errors in both medial (ORu2009=u20094.26, pu2009<u20090.001) and lateral portals (ORu2009=u20093.07, pu2009<u20090.001).ConclusionIn terms of the set-up uncertainty during breast irradiation, patients with extensive error in the initial treatment should be closely observed with serial image-guided radiotherapy.ZusammenfassungZielDas Ziel der Studie war es, eine kundenspezifische Strategie für die bildgesteuerte Radiotherapie während der Bestrahlung der gesamten Brust zu entwickeln. Risikofaktoren und damit assoziierte weitreichende Fehler wurden ermittelt.Patienten und MethodenEine Serie von 176xa0Brüsten von insgesamt 174xa0Patienten wurde retrospektiv bewertet. Elektronische Portalbilder aus 914 medialen und 807 lateralen Richtungen wurden geprüft. Basierend auf der Brustwand wurden die Abweichungen zwischen der Simulation und jeder Behandlung gemessen. Für jede Richtung wurde der systematische (Σ) und der zufällige Fehler (σ) der Bevölkerungsgruppe sowie die Grenze (2Σu2009+u20090,7σ) des geplanten Zielvolumens (PTV) berechnet. Umfangreiche Set-up-Fehler wurden als Fraktion definiert, welche die PTV-Grenzen in jede Richtung überschreitet. Für weitreichende Set-up-Fehler wurden χ2-Tests und logistische Regressionsanalysen durchgeführt.ErgebnisseDie medialen und lateralen PTV-Grenzen für die rechten-linken, superioren-inferioren und anterioren-posterioren Achsen und die Rotation des Kollimators waren jeweils 2,6 und 2,4xa0mm, 4,6 und 4,6xa0mm, 3,1 und 3,3xa0mm sowie 2,8 und 2,9u2009°. Cut-off-Werte für weitreichende Fehler waren jeweils 3, 5 und 4xa0mm bzw. 3u2009°. In den χ2-Tests waren für mediale Portale ein Tumor am oberen äußeren Quadranten (pu2009=u20090,012) und die Brustwanddicke ≥u20092,0xa0cm (pu2009=u20090,003) sowie für laterale Portale die Altersgruppe (pu2009=u20090,036) mit den weitreichenden Fehlern verbunden. In den multivariaten Tests war ein weitreichender Fehler bei der anfänglichen Fraktion mit einer hohen Wahrscheinlichkeit für umfangreiche Set-up-Fehler in beiden medialen (ORu2009=u20094,26; pu2009<u20090,001) und lateralen Portalen (ORu2009=u20093,07; pu2009<u20090,001) verbunden.SchlussfolerungIm Hinblick auf die Set-up-Unsicherheit bei der Brustbestrahlung sollten Patienten mit weitreichenden Fehlern während der anfänglichen Behandlung durch serielle bildgesteuerte Radiotherapie genauer beobachtet werden.

Can intensity-modulated radiation therapy spare the central flapped area while encompassing the target volume in radiotherapy after immediate breast reconstruction?

Radiotherapy increases the morbidity of immediate breast reconstruction. To spare the flapped area without an adverse dose distribution of the target volume and organ at risks, various radiation techniques were assessed.

Study of body surface motion effect using sensor based computer-controlled motion phantom (SBMP) and sensors: US, IR and tilt sensors

This study aims to obtain body surface motion by using a sensor based computer-controlled motion phantom (SBMP) and sensors (US, IR, Tilt), and to develop respiration gating techniques that can adjust patients’ beds by using reversed values of the data obtained. The SBMP made to measure body surface motion is composed of a BS II microprocessor, sensors, host computer and stepping motor etc. And the program to control and operate it was developed. After the SBMP was adjusted by entering random movement data, and the phantom movements were acquired using the sensors, the two data were compared and analyzed. And then, after the movements by respiration were acquired by using a cat, the real-time respiration gating techniques were drawn by operating the phantom with the reversed values of the data. The result of analyzing the acquisition-correction delay time for the data value shows that the data value coincided within 1% and that the acquisition-correction delay time was obtained realtime (2.34 × 10−4 sec). This study successfully confirms the clinical application possibility of respiration gating techniques by using a SBMP and sensors.