Laparoscopic Assisted Distal Rectal Cancer Resection with Preoperative Concurrent Chemoradiotherapy / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Anatomy of deep pelvis, narrow distal margin and tumor invasion into neighbor organ are obstacles for curative radical resection for advanced cancer of distal rectum. Technically, laparoscopic application after downstaging the tumor with preoperative concurrent chemotherapy (CCRT) may give a solution to overcome the anatomical difficulties. We compared the results of laparoscopic surgery in the patients who received CCRT with those of patients who had conventional surgery. MATERIALS AND METHODS: A continuous infusion of 5FU plus leucovorin and radiotherapy (50.4 Gy) in 28 fractions was given each patient as CCRT. They underwent D2 radical resection with TME and ANP for the rectal cancer in 4 weeks. RESULTS: Thirty three patients had laparoscopic resection such as LAR, colo-anal anastomosis and APR. The results were compared with 12 cases of the conventional resections. As a result of preoperative CCRT, the cancer was down-staged in 71%. Two year disease free survival was 75% and 74% in the group of conventional and laparoscopic resection, respectively (p=0.427). Ileus, voiding difficulty and leakage after surgery were not different between two groups. Weakness of ejaculation was noted in 9~11% of both groups. The DFS of the preoperative CCRT followed by radical resection in the groups with a response was more favorable than that in the group with progressive or stable disease. CONCLUSION: Radical resection of advanced distal rectal cancer could be done with performing a laparoscopic assisted operation after CCRT induced down-staging. We may suggest that laparoscopic assisted resection is a good treatment option as it doesn't increase the complications and it has a compatible survival rate to conventional surgery.

Results of Preoperative Concurrent Chemoradiotherapy for Locally Advanced Rectal Cancer / 대한방사선종양학회지

PURPOSE: We performed a retrospective non-randomized clinical study of locally advanced rectal cancer, to evaluate the anal sphincter preservation rates, down staging rates and survival rates of preoperative chemoradiotherapy. MATERIALS AND METHODS: From January 2002 to December 2005, patients with pathologically confirmed rectal cancer with clinical stage T2 or higher, or patients with lymph node metastasis were enrolled in this study. A preoperative staging work-up was conducted in 36 patients. All patients were treated with preoperative chemoradiotherapy, and curative resection was performed for 26 patients at Hallym University Sacred Heart Hospital. Radiotherapy treatment planning was conducted with the use of planning CT for all patients. A total dose of 45.0~52.2 Gy conventionally fractionated three-dimensional radiotherapy was delivered to the whole pelvis. Chemotherapy was given at the first and fifth week of radiation therapy with continuous infusion i.v. 5-FU (Fluorouracil) and LV (Leucovorine). Surgical resection was performed 2 to 4 weeks after the completion of the chemoradiotherapy regimen. RESULTS: The complete resection rate with negative resection margin was 100% (26/26). However, a pathologically complete response was not seen after curative resection. Surgery was done by LAR (low anterior resection) in 23 patients and APR (abdomino-perineal resection) in 3 patients. The sphincter preservation rate was 88.5% (23/26), down staging of the tumor occurred in 12 patients (46.2%) and down-sizing of the tumor occurred in 19 patients (73%). Local recurrence after surgical resection developed in 1 patient, and distant metastasis developed in 3 patients. The local recurrence free survival rate, distant metastasis free survival rate, and progression free survival rate were 96.7%, 87% and 83.1%, respectively. Treatment related toxicity was minimal except for one grade 3, one grade 4 anemia, one grade 3 leukopenia, and one grade 3 ileus. CONCLUSION: Preoperative concurrent chmoradiotherapy for locally advanced rectal cancer seems to have some potential benefits: high sphincter preservation and down staging. Treatment related toxicity was minimal and a high compliance with treatment was seen in this study. Further long-term follow-up with a larger group of patients is required.

Evaluation of Geometric Correspondence of kV X-ray Images, Electric Portal Images and Digitally Reconstructed Radiographic Images / 의학물리

In this study we estimated a geometric correlation among digitally reconstructed radiographic image (DRRI), kV x-ray image (kVXI) from the On-Board Imager (OBI) and electric portal image (EPI). To verify geometric correspondence of DRRI, kVXI and EPI, specially designed phantom with indexed 6 ball bearings (BBs) were employed. After accurate setup of the phantom on a treatment couch using orthogonal EPIs, we acquired set of orthogonal kVXIs and EPIs then compared the absolute positions of the center of the BBs calculated at each phantom plane for kVXI and EPI respectively. We also checked matching result for obliquely incident beam (gantry angle of 315 degrees) after 2D-2D matching provided by OBI application. A reference EPI obtained after initial setup of the phantom was compared with 10 series of EPIs acquired after each 2D-2D matching. Imaginary setup errors were generated from -5 mm to 5 mm at each couch motion direction. Calculated positions of all center positions of the BBs at three different images were agreed with the actual points within a millimeter and each other. Calculated center positions of the BBs from the reference and obtained EPIs after 2D-2D matching agreed within a millimeter. We could tentatively conclude that the OBI system was mechanically quite reliable for image guided radiation therapy (IGRT) purpose.

The Role of Positron Emission Tomography(PET) in Radiation Treatment Planning / 한양의대학술지

Molecular imaging, in particular, positron emission tomography(PET) has brought an additional dimension to management for patients with cancer. It may lead to a change in staging and treatment management. In radiotherapy, the PET or PET-CT has a crucial role in treatment planning and patient management, specifically, its use in disease staging, patient selection, treatment planning and evaluation. The purpose of radiotherapy is radical or palliative depending on the staging of tumor; thus, PET(-CT) may actually change the course of disease. The methodological and technological aspects of PET(-CT) in radiotherapy are discussed, focusing on the problem of target volume definition and tumor motion with respect to imaging and dose delivery. In addition, tissue hypoxia is an important factor in radiotherapy as a resistance factor in treatment; thus, we mention the concept of hypoxia-directed therapy.

Development of an Automatic Seed Marker Registration Algorithm Using CT and kV X-ray Images / 대한방사선종양학회지

PURPOSE: The purpose of this study is to develop a practical method for determining accurate marker positions for prostate cancer radiotherapy using CT images and kV x-ray images obtained from the use of the on-board imager (OBI). MATERIALS AND METHODS: Three gold seed markers were implanted into the reference position inside a prostate gland by a urologist. Multiple digital image processing techniques were used to determine seed marker position and the center-of-mass (COM) technique was employed to determine a representative reference seed marker position. A setup discrepancy can be estimated by comparing a computed COMOBI with the reference COMCT. A proposed algorithm was applied to a seed phantom and to four prostate cancer patients with seed implants treated in our clinic. RESULTS: In the phantom study, the calculated COMCT and COMOBI agreed with COMactual within a millimeter. The algorithm also could localize each seed marker correctly and calculated COMCT and COMOBI for all CT and kV x-ray image sets, respectively. Discrepancies of setup errors between 2D-2D matching results using the OBI application and results using the proposed algorithm were less than one millimeter for each axis. The setup error of each patient was in the range of 0.1+/-2.7~1.8+/-6.6 mm in the AP direction, 0.8+/-1.6~2.0+/-2.7 mm in the SI direction and -0.9+/-1.5~2.8+/-3.0 mm in the lateral direction, even though the setup error was quite patient dependent. CONCLUSION: As it took less than 10 seconds to evaluate a setup discrepancy, it can be helpful to reduce the setup correction time while minimizing subjective factors that may be user dependent. However, the on-line correction process should be integrated into the treatment machine control system for a more reliable procedure.

GafChromic Film Dosimetry for Stereotactic Radiosurgery with a Linear Accelerator / 대한방사선종양학회지

PURPOSE: The purpose of this study was to evaluate whether a GafChromic film applied to stereotactic radiosurgery with a linear accelerator could provide information on the value for acceptance testing and quality control on the absolute dose and relative dose measurements and/or calculation of treatment planning system. MATERIALS AND METHODS: A spherical acrylic phantom, simulating a patient's head, was constructed from three points. The absolute and relative dose distributions could be measured by inserting a GafChromic film into the phantom. We tested the use of a calibrated GafChromic film (MD-55-2, Nuclear Associate, USA) for measuring the optical density. These measurements were achieved by irradiating the films with a dose of 0-112 Gy employing 6 MV photon. To verify the accuracy of the prescribed dose delivery to a target isocenter using a five arc beams (irradiated in 3 Gy per one beam) setup, calculated by the Linapel planning system the absolute dose and relative dose distribution using a GafChromic film were measured. All the irradiated films were digitized with a Lumiscan 75 laser digitizer and processed with the RIT113 film dosimetry system. RESULTS: We verified the linearity of the Optical Density of a MD-55-2 GafChromic film, and measured the depth dose profile of the beam. The absolute dose delivered to the target was close to the prescribed dose of Linapel within an accuracy for the GafChromic film dosimetry (of +/- 3%), with a measurement uncertainty of +/- 1 mm for the 50~90% isodose lines. CONCLUSION: Our results have shown that the absolute dose and relative dose distribution curves obtained from a GafChromic film can provide information on the value for acceptance. To conclude the GafChromic film is a convenient and useful dosimetry tool for linac based radiosurgery.

Application of Intensity Modulated Radiation Therapy (IMRT) in Prostate Cancer / 대한방사선종양학회지

This study was done to implement intensity-modulated radiation therapy (IMRT) for the treatment of primary prostate cancer and to compare this technique with conventional treatment methods. A 72-year- old male patient with prostate cancer stage T2a was treated with IMRT delivered with dynamic multi-leaf collimation. Treatment was designed using an inverse planning algorithm, which accepts dose and dose- volume constraints for targets and normal structures. The IMRT plan was compared with a three-dimensional (3D) plan using the same 6 fields technique. Lower normal tissue doses and improved target coverage were achieved using IMRT at current dose levels, and facilitate dose escalation to further enhance locoregional control and organ movement during radiotherapy is an important issue of IMRT in prostate cancer.

MR Findings of Cervical Lymphadenopathy: Tuberculosis Versus Metastasis

PURPOSE: To determine the MR findings of cervical lymphadenopathy which distinguish tuberculouslymphadenitis(TL) from metastatic lymphadenopathy(ML). MATERIALS AND METHODS: We retrospectively analyzed the MRfindings of 14 patients with TL and 19 with ML. Thirty-nine lesions in 14 patients with TL and 80 lesions in 19with ML were classified into three categories: conglomerate lesion (TL, 7; ML, 8); discrete lesion withoutnecrosis (TL, 3; ML, 15); and discrete lesion with necrosis (TL, 29; ML, 57). Between TL and ML, we compared age,sex, bilaterality, multiplicity, associated pulmonary tuberculosis, infiltration of adjacent fat, muscle, skin andsubcutaneous tissue, margin, and signal intensities on T1- and T2-weighted images. In discrete lesion, we alsocompared the minimal to maximal dimension ratio, and in discrete necrotic lesion, the thickness and evenness ofrim enhancement, and the location and extent of necrosis. RESULTS: There were statistically significantdifferences between TL and ML in age(34.7+/-13.1 years; 56.1+/-14.3 years), male to female ratio(3:11; 13:6),bilaterality(1/14; 10/19), multiplicity(5/14; 14/19), and associated active pulmonary tuberculosis(7/14; 1/19). OnT2-weighted images, TL showed predominantly homogeneous (30/39) or high (20/39) signal intensity, similar to thatof cerebrospinal fluid, but the signal inteusity of ML was predominantly heterogeneous(58/80), or lower than orsimilar to that of fat(41/80). Between TL and ML, however, there were no statistically significant differences ininfiltration of adjacent tissue, margin, signal intensity and its heterogeneity on T1-weighted image, minimal tomaximal dimension ratio, thickness and evenness of rim enhancement, or the location and extent of necrosis. CONCLUSION: In cervical lymphadenopathy, the existence of TL rather than ML is suggested by single or unilaterallesion in a young woman, by associated active pulmonary tuberculosis, or by homogeneous high signal intensity onT2-weighted MR images.

The Results of Radiation Therapy in Stage III Non-Small Cell Lung Cancer / 대한치료방사선과학회지

PURPOSE: To evaluate the survival and prognostic factors in patients with stage III non-small cell lung cancer treated with curative radiotherapy alone or combined with chemotherapy. MATERIALS AND METHODS: A retrospective analysis was undertaken of 35 patients who had locally advanced non-small-cell lung cancer and t treated with curative radiotherapy in Department of Therapeutic Radiology, Kangdong Sacred Heart Hospital, from January 1991 through December 1993. According to AJCC staging, 15 patients were stage IIIA, and 20 were stage IIIB. Radotherapy was delivered with 1.8-2 Gy per fraction/day, 5 days per week using 6 MV X-ray, to a total dose ranging from 48.8 Gy to 66.6 Gy(median, 61.2 Gy) in 4 to 9 weeks. Ten patients received neoadjuvant or concurrent chemotherapy with FIP (5-FU, ifosfamide, and cisplatin) or FP(5-FU and cisplatin). RESULTS: For all patients, median survival was 6 months, 1-year and 2-year survival rates were 23.3% and 6.7%, respectively. The median survival was 8 months in stage IIIA and 5.5 months in stage IIIB. In patients treated with radiation therapy alone, median survival was 5 months and 1-year survival rate was 9%. In patients who received chemotherapy, median survival was 11 months and 1-year survival rate was 60%. The difference of survival between these two groups was statistically significant (p=0.03). Total radiation dose, degree of response, and post-treatment ECOG score were also significantly associated with survival. But it was not affected by age, sex, pretreatment ECOG score, presence or absence of weight loss, tumor location, pathologic type, N stage, and degree of response to treatment. CONCLUSION: Conventional radiotherapy alone is unlikely to achieve long term survival in patients with stage III NSCLC. Radiotherapy with altered fractionation schedule or multimodality treatment combined with surgery and/or chemotherapy should be considered if feasible.

The Effect of Aquaplast on Surface Dose of Photon Beam / 대한치료방사선과학회지

PURPOSE: To evaluate the effect on surface dose due to Aquaplast used for immobilizing the patients with head and neck cancers in photon beam radiotherapy. MATERIALS AND METHODS: To assess surface and buildup region dose for 6MV X-ray from linear accelerator(Siemens Mevatron 6740), we measured percent ionization value with the Markus chamber model 30-329 manufactured by PTW Frieburg and Capintec electrometer, model WK92. For measurement of surface ionization value, the chamber was embedded in 25 X 25 X 3 cm3 acrylic phantom and set on 25 X 25 X 5 cm3, polystyrene phantom to allow adequate scattering. The measurements of percent depth ionization were made by placing the polystyrene layers of appropriate thickness over the chamber. The measurements were taken at 10 cm SSD for 5 X 5 cm2 , 10 X 10 cm2 , and 15 X 15 cm2 field sizes, respectively. Placing the layer of Aquaplast over the chamber, the same procedures were repeated. We evaluated two types o Aquaplast: 1.6mm layer of original Aquaplast(manufactured by WFR Aquaplast Corp.) and transformed Aquaplast similar to moulded one for immobilizing the patients practically. We also measured surface ionization values with blocking tray in presence or absence of transformed Aquaplast. In calculating percent depth dose, we used the formula suggested by Gerbi and khan to correct overresponse of the Markus chamber. RESULTS: he surface doses for open fields of 5 X 5 cm2 , 10 X 10 cm2 , 15 X 15 cm2 were 7.9%, 13.6%, and 18.7% respectively. He original Aquaplast increased the surface doses upto 38.4%, 43.6% and 47.4% respectively. There were little differences in percent depth dose values beyond the depth of Dmax. Increasing field size, the blocking tray caused increase of the surface dose by 0.2%, 1.7%, 3.0% without Aquaplast, 0.2%, 1.9%, 3.7% with transformed Aquaplast, respectively. CONCLUSION: The original and transformed Aquaplast increased the surface dose moderately. The percent depth doses beyond Dmax, however, were not affected by Aquaplast. In conclusion, although the use of Aquaplast in practice may cause some increase of skin an dbuildup region dose, reduction of skin-sparing effect will not be so significant clinically.

Acute Myocardial Infarction after Radiation Therapy for Left Sided Breast Cancer

Radiation therapy is one of the cardial therapeutic modality on breast cancer. Three decades ago, the heart was considered to be radioresistant, but now it is generally recognized that the heart is also radiosensitive. The most common clinical syndromes after irradiation are pericarditis in acute and chronic forms, cardiomyopathy, valvular disease and, to a lesser degree, complete atrioventricular block. However, lesions of coronary vessels had been considered exceptionally rare and even questionable. And then there have been a few case reports for acute myocardial infartion after irradiation for left sided breast cancer and it may be considered that radiation therpy can injure endothelium of coronary artery and cause ischemic coronary artery disease. We report the case of a 38 years old women who developed acute anterior wall myocardial infarction after irradiation for left sided breast cancer.

External Radiation Therapy Combined with Hyperthermia in the Carcinoma of Extrahepatic Biliary System / 대한치료방사선과학회지

From January 198e to September 1990,7 patients with carcinoma of the extrahepatic biliary system received external radiaiton therapy combined with hyperthermia. of the 3 patients with extrahepatic bile duct cancer, two were primary cholangiocarcinoma and one was metastatic peripancreatic carcinoma. Of the 4 patients with carcinoma of the gallbladder, two were locoregionally advanced and unresectable carcinoma and the remaining two were local-regional recurrence after cholecystectomy. They were all pathologicallly proven adenocarcinoma. The radiation dose received ranged from 3000 cGy/2weeks to 5040 cGy/ 7weeks. The hyperthermia was done once or twice a week and 4 to 12 sessions in total. The tumor response was confirmed by T-tube cholangiography, percutaneous transhepatic cholangiography and CT scan. 6 out of 7(86%) showed partial regression of the tumor. The median survival time was 7 months (range 4~11 Months). 6 out of 7 patients were dead : one died of septicemia, 4 of primary disease, one of distant metastases. Only one out of 7 patients is still alive but new metastatic lesion was found. There was not any treatment related deaths. There was also no evidence of treatment related problems with liver, stomach and duodenum, although the observation period was short.

Combined Treatment of Residual, Recurrent and Unresectable gastric Cance / 대한치료방사선과학회지

A series of 25 patients with residual, recurrent, and unresectable gastric cancer received various combination of surgery, radiotherapy (RT), chemotherapy (CT), and hyperthermia (HT). They were placed into 7 categories; 1) CT and HT-14 patients; 2) RT and HT-15 patients; 3) surgery, RT and HT-2 patients; 4) surgery, RT, HT and CT-1 patient; 5) RT, HT and CT-1 patient; 6) RT and CT-1 patient; 7) RT alone-1 patient. Three patients had curative resection. 21 patients received irradiation with tightly contoured portals to spare as much small bowel, kidney and marrow as possible. Hyperthermia was applied regionally once or twice a week for 23 patients using 8 MHz radiofrequency capacitive heating device (Thermotron RF-8). HT was given approximately 30 min after RT. 7 patients were treated with CT: 4 patients received HT and concomitant Mitomycin-C; 3 patients received HT and sequential 5-FU+Adriamycin+Mitomycin-C. There was not any treatment related deaths. There was also no evidence of treatment related problems with liver, kidney, stomach, or spinal cord except only one case of transient diabetic ketoacidosis. The tumor response was evaluable in 22 patients. None achieved complete remission. 11(50%) achieved partial remission. The response rate was correlated with total radiation dose and achieved maximum temperature. 9 of 14 (64%) received more than 4000 cgy showed partial remission; especially, all 3 patients received more than 5500 cgy achieved partial response. 8 of the 12 patients (67%) who achieved maximal temperature more than 41degrees C showed partial response in comparing with 25% (2 of 8 patients, below 41degrees C). The numbers of HT, however, was not correlated with the response. 3 of the 25 patients (12%) remain alive. The one who was surgically unresectable and underwent irradiation alone is in progression of the disease with distant metastases. The remaining two patients with curative resection are alive with free of disease, 24 and 35 months, respectively. The median survival by response are11.5 months in responders and 4.6 months in non-responders.

The Effect of Hyperthermia Combined with Radiation on Crypts of the Mouse Jejunum / 대한치료방사선과학회지

The effect of local hyperthermia of 41 to 43degree C for 30 minutes on radiosensitivity of normal tissue was studied utilizing jejunal crypt microcolony assay. Hyperthermia of this range enhanced the radiation effect and the effect was mainly additive without significant effect on the slopes of cell survival curves. At the isoeffect level of 20 microcolony formation, the thermal enhancement ratio was 1.02, 1.10 and 1.39 for 41degree 42degreeand 43degree C, respectively. The distribution of microcolony formation along the circumference of jejunum was not uniform, having more colonies around the mesenteric border, and this suggests the effect of uneven cooling by blood circulation.

The role of computed tomography in the laryngeal injury

CT of the laynx represents a major advance in laryngology, Even in severe injury the larynx can be examinedeasily and conveniently by CT at the same times the brain and facial structures without moving the patient, whoneed only lie down and breathe quietly during the study. CT permitted a much more detailed appraisal of layrngealdysfunction in patients with blunt laryngeal trauma (3 cases) and strangulation injury (2 cases). CT of the larynxundoubtedly played a determinant role in patient management. CT was helpful in evaluating the laryngeal cartilagesand deep spaces of the larynx wthich was difficult to examine by the laryngoscope. Follow-up CT made it possibleto evaluate the postoperative results.

Computed tomography of 3 cases of hip trauma

CT has been advocated as an adjunct to conventional radiography in the evaluation of pelvic bone fractures andtraumatic dislocations of the femoral head. Author compared and analysed the CT and plain radiographic findings of3 consecutive adult patients in whom acetabular or femoral head injuries were suspected or demonstrated on initialradiographs. The results were as follows; 1. CT was convenient and precise method in evaluation the patient withhip trauma. 2. CT was helpful in detecting intraaraticular osseous fragment, interposed soft tissue, and wideningof the joint space which was not evident on plain radiographs. 3. CT permitted better evaluation of asociatedinjuries in soft tissue and viscera in the plevic and retroperitoneal cavity, and also gave information aboutother associated fractures. 4. CT was superior for the evaluation of posterior acetabular rim and medial portionof the acetabulum. 5. CT was helpful for evaluating the presence or absence of intraarticular osseous fragmentsafter reduction of the dislocated hip.