Analysis of Predictive Factors for Lung Injury after Forward-Planned Intensity-Modulated Radiotherapy in Whole Breast Irradiation / 한국유방암학회지

PURPOSE: This study was performed to assess frequency, timings of occurrence, and predictors of radiologic lung damage (RLD) after forward-planned intensity-modulated radiotherapy (FIMRT) for whole breast irradiation. METHODS: We retrospectively reviewed medical records of 157 breast cancer patients and each of their serial chest computed tomography (CT) taken 4, 10, 16, and 22 months after completion of breast radiotherapy (RT). FIMRT was administered to whole breast only (n=152), or whole breast and supraclavicular regions (n=5). Dosimetric parameters, such as mean lung dose and lung volume receiving more than 10 to 50 Gy (V10-V50), and clinical parameters were analyzed in relation to radiologic lung damage. RESULTS: In total, 104 patients (66.2%) developed RLD after whole breast FIMRT. Among the cases of RLD, 84.7% were detected at 4 months, and 15.3% at 10 months after completion of RT. More patients of 47 or younger were found to have RLD at 10 months after RT than patients older than the age (11.7% vs. 2.9%, p=0.01). In univariate and multivariate analyses, age >47 and V40 >7.2% were significant predictors for higher risk of RLD. CONCLUSION: RLD were not infrequently detected in follow-up CT after whole breast FIMRT. More detected cases of RLD among younger patients are believed to have developed at later points after RT than those of older patients. Age and V40 were significant predictors for RLD after whole breast intensity-modulated radiotherapy.

Implementation and Evaluation of the Electron Arc Plan on a Commercial Treatment Planning System with a Pencil Beam Algorithm / 의학물리

Less execution of the electron arc treatment could in large part be attributed to the lack of an adequate planning system. Unlike most linear accelerators providing the electron arc mode, no commercial planning systems for the electron arc plan are available at this time. In this work, with the expectation that an easily accessible planning system could promote electron arc therapy, a commercial planning system was commissioned and evaluated for the electron arc plan. For the electron arc plan with use of a Varian 21-EX, Pinnacle3 (ver. 7.4f), with an electron pencil beam algorithm, was commissioned in which the arc consisted of multiple static fields with a fixed beam opening. Film dosimetry and point measurements were executed for the evaluation of the computation. Beam modeling was not satisfactory with the calculation of lateral profiles. Contrary to good agreement within 1% of the calculated and measured depth profiles, the calculated lateral profiles showed underestimation compared with measurements, such that the distance-to-agreement (DTA) was 5.1 mm at a 50% dose level for 6 MeV and 6.7 mm for 12 MeV with similar results for the measured depths. Point and film measurements for the humanoid phantom revealed that the delivered dose was more than the calculation by approximately 10%. The electron arc plan, based on the pencil beam algorithm, provides qualitative information for the dose distribution. Dose verification before the treatment should be mandatory.

Estimation of Jaw and MLC Transmission Factor Obtained by the Auto-modeling Process in the Pinnacle3 Treatment Planning System / 의학물리

Radiation treatment techniques using photon beam such as three-dimensional conformal radiation therapy (3D-CRT) as well as intensity modulated radiotherapy treatment (IMRT) demand accurate dose calculation in order to increase target coverage and spare healthy tissue. Both jaw collimator and multi-leaf collimators (MLCs) for photon beams have been used to achieve such goals. In the Pinnacle3 treatment planning system (TPS), which we are using in our clinics, a set of model parameters like jaw collimator transmission factor (JTF) and MLC transmission factor (MLCTF) are determined from the measured data because it is using a model-based photon dose algorithm. However, model parameters obtained by this auto-modeling process can be different from those by direct measurement, which can have a dosimetric effect on the dose distribution. In this paper we estimated JTF and MLCTF obtained by the auto-modeling process in the Pinnacle3 TPS. At first, we obtained JTF and MLCTF by direct measurement, which were the ratio of the output at the reference depth under the closed jaw collimator (MLCs for MLCTF) to that at the same depth with the field size 10x10 cm2 in the water phantom. And then JTF and MLCTF were also obtained by auto-modeling process. And we evaluated the dose difference through phantom and patient study in the 3D-CRT plan. For direct measurement, JTF was 0.001966 for 6 MV and 0.002971 for 10 MV, and MLCTF was 0.01657 for 6 MV and 0.01925 for 10 MV. On the other hand, for auto-modeling process, JTF was 0.001983 for 6 MV and 0.010431 for 10 MV, and MLCTF was 0.00188 for 6 MV and 0.00453 for 10 MV. JTF and MLCTF by direct measurement were very different from those by auto-modeling process and even more reasonable considering each beam quality of 6 MV and 10 MV. These different parameters affect the dose in the low-dose region. Since the wrong estimation of JTF and MLCTF can lead some dosimetric error, comparison of direct measurement and auto-modeling of JTF and MLCTF would be helpful during the beam commissioning.

A Monte Carlo Simulation for the Newly Developed Head-and-Neck IMRT Phantom: a Pilot Study / 의학물리

A head-and-neck phantom was designed in order to evaluate remotely the quality of the delivery dose of intensity modulated radiation therapy (IMRT) in each institution. The phantom is homogeneous or inhomogeneous by interchanging the phantom material with the substructure like an air or bone plug. Monte Carlo simulations were executed for one beam and three beams to the phantom and compared with ion chamber and thermoluminescent dosimeter (TLD) measurements of which readings were from two independent institutions. For single beam, the ion chamber results and the MC simulations agreed to within about 2%. TLDs agreed with the MC results to within 2% or 7% according to which institution read the TLDs. For three beams, the ion chamber results showed -5% maximum discrepancy and those of TLDs were +2~+3%. The accuracy of the TLD readings should be increased for the remote dose monitoring. MC simulations are a valuable tool to acquire the reliability of the measurements in developing a new phantom.

Small Bowel Sparing Effect of Small Bowel Displacement System in 3D-CRT and IMRT for Cervix Cancer / 대한방사선종양학회지

PURPOSE: In radiotherapy for cervix cancer, both 3-dimensioal radiotherapy (3D-CRT) and intensity-modulated radiation therapy (IMRT) could reduce the dose to the small bowel (SB), while the small bowel displacement system (SBDS) could reduce the SB volume in the pelvic cavity. To evaluate the effect of the SBDS on the dose to the SB in 3D-CRT and IMRT plans, 3D-CRT and IMRT plans, with or without SBDS, were compared. MATERIALS AND MEHTODS: Ten consecutive uterine cervix cancer patients, receiving curative radiotherapy, were accrued. Ten pairs of computerized tomography (CT) scans were obtained in the prone position, with or without SBDS, which consisted of a Styrofoam compression device and an individualized custom-made abdominal immobilization device. Both 3D-CRT, using the 4-field box technique, and IMRT plans, with 7 portals of 15 MV X-ray, were generated for each CT image, and prescribed 50 Gy (25 fractions) to the isocenter. For the SB, the volume change due to the SBDS and the DVHs of the four different plans were analyzed using paired t-tests. RESULTS: The SBDS significantly reduced the mean SB volume from 522 to 262 cm3 (49.8% reduction). The SB volumes that received a dose of 10~50 Gy were significantly reduced in 3D-CRT (65~80% reduction) and IMRT plans (54~67% reduction) using the SBDS. When the SB volumes that received 20~50 Gy were compared between the 3D-CRT and IMRT plans, those of the IMRT without the SBDS were significantly less, by 6~7%, than those for the 3D-CRT without the SBDS, but the volume difference was less than 1% when using the SBDS. CONCLUSION: The SBDS reduced the radiation dose to the SB in both the 3D-CRT and IMRT plans, so could reduce the radiation injury of the SB.

Treatment Outcome and Analysis of the Prognostic Factors of Ductal Carcinoma in situ Treated with Breast Conserving Surgery and Radiotherapy / 대한방사선종양학회지

PURPOSE: To evaluate the survival rate, local failure rate and patterns of failure, and analyze the prognostic factors affecting local relapse of ductal carcinoma in situ treated with breast conserving surgery and radiotherapy Materials and Methods: From June 1995 to December 2001, 96 patients with ductal carcinoma in situ treated with breast conserving surgery and radiotherapy were retrospectively analyzed. The operations were either local or wide excision in all patients, with an axillary lymph node dissection performed in some patients. Radiation dose to the whole breast was 50.4 Gy, over 5 weeks, with 1.8 Gy daily fractions, with additional doses (10~14 Gy) administered to the primary tumor bed in some patients with close (< or =2 mm) or positive resection margin. The median follow-up period was 43 months (range 12~102 months). RESULTS: The 5-year local relapse free survival and overall survival rates were 91 and 100% respectively. Local relapse occurred in 6 patients (6.3%). Of the 6 recurrences, one was invasive ductal cell carcinoma. With the exception of one, all patients recurred 2 years after surgery. There was no regional recurrence or distant metastasis. Five patients with local recurrence were salvaged with total mastectomy, and are alive with no evidence of disease. One patient with recurrent invasive ductal cell carcinoma will receive salvage treatment. On analysis of the prognostic factors affecting local relapse, none of the factors among the age, status of resection margin, comedo type and nuclear grade affected local relapse. Operation extent also did not affect local control (p=0.30). In the patients with close resection margin, boost irradiation to the primary tumor bed did not affect local control (p=1.0). CONCLUSIONS: The survival rate and local control of the patients with ductal carcinoma in situ treated with breast conserving surgery and radiotherapy were excellent. Close resection margin and boost irradiation to the primary tumor bed did not affect local relapse, but further follow-up with much more patients is needed.

Analysis of the Causes of Subfrontal Recurrence in Medulloblastoma and Its Salvage Treatment / 대한방사선종양학회지

PURPOSE: Firstly, to analyze factors in terms of radiation treatment that might potentially cause subfrontal relapse in two patients who had been treated by craniospinal irradiation (CSI) for medulloblastoma. Secondly, to explore an effective salvage treatment for these relapses. MATERIALS AND METHODS: Two patients who had high-risk disease (T3bM1, T3bM3) were treated with combined chemoradiotherapy. CT-simulation based radiation-treatment planning (RTP) was performed. One patient who experienced relapse at 16 months after CSI was treated with salvage surgery followed by a 30.6 Gy IMRT (intensity modulated radiotherapy). The other patient whose tumor relapsed at 12 months after CSI was treated by surgery alone for the recurrence. To investigate factors that might potentially cause subfrontal relapse, we evaluated thoroughly the charts and treatment planning process including portal films, and tried to find out a method to give help for placing blocks appropriately between subfrotal-cribrifrom plate region and both eyes. To salvage subfrontal relapse in a patient, re-irradiation was planned after subtotal tumor removal. We have decided to treat this patient with IMRT because of the proximity of critical normal tissues and large burden of re-irradiation. With seven beam directions, the prescribed mean dose to PTV was 30.6 Gy (1.8 Gy fraction) and the doses to the optic nerves and eyes were limited to 25 Gy and 10 Gy, respectively. RESULTS: Review of radiotherapy portals clearly indicated that the subfrontal-cribriform plate region was excluded from the therapy beam by eye blocks in both cases, resulting in cold spot within the target volume. When the whole brain was rendered in 3-D after organ drawing in each slice, it was easier to judge appropriateness of the blocks in port film. IMRT planning showed excellent dose distributions (Mean doses to PTV, right and left optic nerves, right and left eyes: 31.1 Gy, 14.7 Gy, 13.9 Gy, 6.9 Gy, and 5.5 Gy, respectively. Maximum dose to PTV: 36 Gy). The patient who received IMRT is still alive with no evidence of recurrence and any neurologic complications for 1 year. CONCLUSION: To prevent recurrence of medulloblastoma in subfrontal-cribriform plate region, we need to pay close attention to the placement of eye blocks during the treatment. Once subfrontal recurrence has happened, IMRT may be a good choice for re-irradiation as a salvage treatment to maximize the differences of dose distributions between the normal tissues and target volume.

Partial Breast Irradiation (PBI) / 한국유방암학회지

Breast conservation treatment (BCT) is a combination of breast conservation surgery (BCS) and radiotherapy (RT). Conventional radiotherapy after BCS requires 5~6 weeks of RT to whole breast followed by 1~2 weeks of RT to tumor bed. This lengthy tretment modality is one of the difficulties in performing BCT. Recently, irradiation to the tumor bed only (partial breast irradiation, PBI) in selected patients was examined as a way to shorten the period of RT because a local recurrence after a BCT occurs mainly around the primary tumor bed. PBI with a large fractional dose might shorten the treatment time to one week. There are various methods of PBI including interstitial brachytherapy, balloon brachytherapy, external beam radiotherapy such as three-dimensional conformal radiotherapy, intensity modulated radiotherapy and proton therapy, and intraoperative radiotherapy. The results of the phase I/II studies using these new techniques have reported a similar local control rate and cosmetic results compared with the historical data using whole breast irradiation (WBRT). However, a long-term follow-up of the phase III randomized trials will be needed in order to determine the equivalence of PBI alone to WBRT in the treatment of selected patients with early breast cancer.

Radiation Dose-escalation Trial for Glioblastomas with 3D-conformal Radiotherapy / 대한방사선종양학회지

PURPOSE: To investigate the effects of radiation dose-escalation on the treatment outcome, complications and the other prognostic variables for glioblastoma patients treated with 3D-conformal radiotherapy (3D-CRT). MATERIALS AND METHODS: Between Jan 1997 and July 2002, a total of 75 patients with histologically proven diagnosis of glioblastoma were analyzed. The patients who had a Karnofsky Performance Score (KPS) of 60 or higher, and received at least 50 Gy of radiation to the tumor bed were eligible. All the patients were divided into two arms; Arm 1, the high-dose group was enrolled prospectively, and Arm 2, the low-dose group served as a retrospective control. Arm 1 patients received 63~70 Gy (Median 66 Gy, fraction size 1.8~2 Gy) with 3D-conformal radiotherapy, and Arm 2 received 59.4 Gy or less (Median 59.4 Gy, fraction size 1.8 Gy) with 2D-conventional radiotherapy. The Gross Tumor Volume (GTV) was defined by the surgical margin and the residual gross tumor on a contrast enhanced MRI. Surrounding edema was not included in the Clinical Target Volume (CTV) in Arm 1, so as to reduce the risk of late radiation associated complications; whereas as in Arm 2 it was included. The overall survival and progression free survival times were calculated from the date of surgery using the Kaplan-Meier method. The time to progression was measured with serial neurologic examinations and MRI or CT scans after RT completion. Acute and late toxicities were evaluated using the Radiation Therapy Oncology Group neurotoxicity scores. RESULTS: During the relatively short follow up period of 14 months, the median overall survival and progression free survival times were 15+/-1.65 and 11+/-0.95 months, respectively. There was a significantly longer survival time for the Arm 1 patients compared to those in Arm 2 (p=0.028). For Arm 1 patients, the median survival and progression free survival times were 21+/-5.03 and 12+/-1.59 months, respectively, while for Arm 2 patients they were 14+/-0.94 and 10+/-1.63 months, respectively. Especially in terms of the 2-year survival rate, the high-dose group showed a much better survival time than the low-dose group; 44.7% versus 19.2%. Upon univariate analyses, age, performance status, location of tumor, extent of surgery, tumor volume and radiation dose group were significant factors for survival. Multivariate analyses confirmed that the impact of radiation dose on survival was independent of age, performance status, extent of surgery and target volume. During the follow-up period, complications related directly with radiation, such as radionecrosis, has not been identified. CONCLUSION: Using 3D-conformal radiotherapy, which is able to reduce the radiation dose to normal tissues compared to 2D-conventional treatment, up to 70 Gy of radiation could be delivered to the GTV without significant toxicity. As an approach to intensify local treatment, the radiation dose escalation through 3D-CRT can be expected to increase the overall and progression free survival times for patients with glioblastomas.

High Dose Radiation Therapy Concurrent with Chemotherapy in Locally Advanced Nasopharynx Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Here, our results from a prospective treatment protocol of concurrent radiochemotherapy (CRCT), which was conducted for locally advanced nasopharynx cancers, between April 1994 and May 2001, are reported. MATERIALS AND METHODS: A total of 52 consecutive eligible patients were accumulated for this protocol. The median radiation doses to the primary site, involved nodes and uninvolved neck were 72, 61.2 and 45 Gy, using a serial shrinking field technique. The boost techniques were 3-dimensional conformal radiation therapy in 45, intracavitary brachytherapy in 3 and 2-dimensional radiation therapy, with multiple small fields, in 2 patients. Two chemotherapy regimens were used: the first regimen, used in 8 patients during the earlier part of the study duration, consisted of 2 cycles of cisplatin plus 5- fluorouracil every 4 weeks, with concurrent radiation therapy, and 4 cycles with the same agents every 4 weeks, adjuvantly; the second regimen, used in 44 patients during the later part, consisted of 3 cycles of cisplatin every 3 weeks, with concurrent radiation therapy and 3 cycles of adjuvant cisplatin plus 5-fluorouracil every 3 weeks. RESULTS: The median follow-up period of the survivors was 32 months. The male to female ratio was 36/16, with a median age of 48 years. The stages, according to the new AJCC staging system (1997), were IIb in 6, III in 23, IVa in 14 and IVb in 9 patients. Fifty and 32 patients completed the planned radiation therapy and concurrent chemotherapy, respectively. Two patients died, 1 of septic shock during the CRCT and the other of malnutrition during the adjuvant chemotherapy. There were 12 failures in 11 patients: 7 locoregional recurrences, 1 within and 6 outside the radiation target volume, and 5 distant metastases. The locoregional control, disease-free survival and overall survival rates were 84.3, 78.8 and 92.8% at 3 years, respectively. CONCLUSION: High dose radiation therapy, coupled with concurrent chemotherapy, was judged a highly effective treatment for locally advanced nasopharynx cancers.

Patterns of Failure and Prognostic Factors in Anal Cancer Treated with Radiotherapy / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: To analyze the patterns of failure and prognostic factors affecting the local control and survivals in anal cancer treated with definitive radiotherapy, and to find the most effective treatment modality. MATERIALS AND METHODS: Thirty consecutive patients, with primary cancers of the anal canal, were treated using radiotherapy, both with and without 5-FU based concurrent chemotherapy. According to the AJCC tumor stage, six patients hadwere stage I, 11 had stage II, 2 had stage IIIA, and 11 had stage IIIB tumors. The median radiation dose was 45 Gy (30-72 Gy), and with 23 patients receivinged concurrent chemotherapy (5-FU and mitomycin C in 12 patients, 5-FU and cisplatin in 7, and other drugs in 4). The Mmedian follow up period was 43 months, (ranginge, from 8- to 99 months). RESULTS: Among the 1630 patients who16 were treated without surgical resection beforeprior to the radiotherapy, and a complete remission was observed in 12 patients (75%), a partial remission in 3 (19%), and a local progression in the other one patient. The Llocal failures, including persistent disease, were observed in 10 (33%), and the patients with higher T-stages (T3-4) had higher rates of local failure rates (T1-2, 21% vs. T3-4, 72%, p=0.03). Distant metastases were found in 4 patients (13%). The five year survival and disease free survival rates were 64% and 53%, respectively. The factors which affectinged the 5 year local relapse free survival were T-stage (74.9% in T1-2 vs. 28.6% in T3-4, p=0.01), and the existence of a gross tumor beforeprior to radiotherapy (84.6%, no residual vs. 45.1% with residual, p=0.03). CONCLUSION: A Llocal recurrence was the major failure pattern in anal cancers, and the factors affecting a local failure were the T-stage and tumor volume beforeprior to radiotherapy. A Rradiation dose around 45 Gy was sufficient to control tumors of the earlier T stage tumors, but a higher dose should be considered for with more advanced lesions.

The Relation between Histopathologic Findings on Surgical Specimen and Outcomes in Patients with N2 Positive Stage IIIA Non-Small Cell Lung Cancer Receiving Preoperative Concurrent Radiochemotherapy and Surgery / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: To evaluate the prognostic implication of histopathologic findings on the surgical specimens of N2 positive stage IIIA non-small cell lung cancer (NSCLC) patients who were treated with preoperative concurrent radiochemotherapy (CRCT) and surgery. MATERIALS AND METHODS: From May 1997 to April 2000, 48 patients with N2 positive stage IIIA NSCLC were treated with preoperative CRCT and surgery. Retrospective analyses were performed on 33 patients who underwent surgical resection. The thoracic radiation therapy (TRT) dose was 45 Gy over 5 weeks with a 1.8 Gy daily fraction using 10 MV X-rays. Chemotherapy consisted of two cycles of intravenous cisplatin (100 mg/m2, on days 1 and 29) and oral etoposide (50 mg/m2/day, on days 1~14 and 29~42), concurrently delivered with TRT. Surgery was performed around 4 weeks of the completion of CRCT. The median follow up was 18 months. The histopathologic findings, including the proportions of viable tumor cells, fibrosis, and necrosis, as well as the tumor and nodal statuses on the surgical specimens following the preoperative CRCT, were analyzed. RESULTS: The 3-year overall survival, disease-free survival, and local control rates were 46.1%, 49.5%, and 85.5%, respectively. Post-surgical stages decreased in 18 patients (54.5%), including 3 pathologic complete responses, were unchanged in 13 (39.4%), and increased in two (6.1%). On univariate analyses, the low proportion of the viable tumor cells was the only factor favorably affecting the overall survival rate (p=0.0386), and the histologic type of squamous cell carcinoma was a favorable factor affecting disease free survival rate (p=0.0452). On multivariate analyses, however, no factor affected the overall survival, disease free survival, or local control rates. CONCLUSION: The histopathologic findings of the proportion of viable tumor cells, fibrosis, and necrosis on the surgical specimens following preoperative CRCT had few prognostic implications on uni-and multi-variate analyses. Furthermore, the primary tumor and nodal responses to preoperative CRCT did not influence the outcomes. Longer-term follow-up with a larger number of patients, however, is awaited.

Preoperative Concurrent Radio-chemotherapy for Rectal Cancer: Report of Early Results / 대한방사선종양학회지

PURPOSE: To report the early results of preopeartive concurrent radio-chemotherapy (CRCT) for treating rectal cancer. MATERIALS AND METHODS: From June 1999 to April 2002, 40 rectal cancer patients who either had lesions with a questionable resectability or were candidates for sphincter-sacrificing surgery received preoperative CRCT. Thirty-seven patients completed the planned CRCT course. 45 Gy by 1.8 Gy daily fraction over 5 weeks was delivered to the whole pelvis in the prone position. The chemotherapy regimens were oral UFT plus oral leucovorin (LV) in 12 patients, intravenous bolus 5-FU plus LV in 10 patients, and intravenous 5-FU alone in 15 patients (bolus infusion in 10, continuous infusion in 5). Surgery was planned in 4~6 weeks of the completion of the preoperative CRCT course, and surgery was attempted in 35 patients. RESULTS: The compliance to the current preoperative CRCT protocol was excellent, where 92.5% (37/40) completed the planned treatment. Among 35 patients, in whom surgery was attempted after excluding two patients with new metastatic lesions in the liver and the lung, sphincter-preservation was achieved in 22 patients (62.9%), while resection was abandoned during laparotomy in two patients (5.7%). Gross complete resection was performed in 30 patients, gross incomplete resection was performed in one patient, and no detailed information on the extent of surgery was available in two patients. Based on the surgical and pathological findings, the down-staging rate was 45.5% (15/33), and the complete resection rate with the negative resection margin 78.8% (26/33). During the CRCT course, grade 3~4 neutropenia developed in four patients (10.8%). Local recurrence after surgical resection developed in 12.1% (4/33), and distant metastases after the preoperative CRCT start developed in 21.6% (8/37). The overall 3-years survival rate was 87%. CONCLUSION: Preoperative CRCT in locally advanced rectal cancer is well tolerated and can lead to high resection rate, down-staging rate, sphincter preservation rate, however, longer term follow-up will be necessary to confirm these results.

Results of Curative Treatment for Cancer of the Tonsil / 대한방사선종양학회지

PURPOSE: To report the results of curative treatment for patients with tonsil cancer by retrospective analysis. MATERIALS AND METHODS: From Jan. 1995 till Dec. 2000, 27 patients with squamous cell carcinoma of the tonsil received curative treatment at Samsung Medical Center. Therapeutic decision was made through multidisciplinary conference, and curative radiation therapy was favored when, (1) the patient's condition was not fit for general anesthesia and surgery, (2) the patient refused surgery, (3) complete resection was presumed impossible, or (4) too severe disability was expected after surgery. Surgery was the main local modality in 17 patients (S+/-RT group), and radiation therapy in 10 (RT+/-CT group). The median follow-up period was 41 months. RESULTS: AJCC stages were I/II in four, III in two, and Iv in 21 patients. The 5-year disease-free survival rate was 73.3% in all patients, 70.6% in the S+/-RT group, and 77.8% in the RT+/-CT group. Treatment failure occurred in seven patients, all with stage III/IV, and all the failures occurred within 24 months of the start of treatment. Five patients among the S CT group developed treatment failures; 2 local, 2 regional, and 1 distant (crude rate=29.4%). Two patients among the RT+/-CT group developed failures; 1 synchronous local and regional, and 1 distant (crude rate=20.0%). The 5-year overall survival rate was 77.0% in all patients, 80.9% in the S+/-RT group, and 70.0% in the RT+/-CT group. CONCLUSION: We could achieve favorable results that were comparable to previously reported data with respect to both the rates of local control and of survival by applying S+/-RT and RT+/-CT. RT+/-CT is judged to be an alternative option that can avoid the functional disability after surgical resection.

Preliminary Results of Paclitaxel, Cisplatin and Concurrent High-Dose Radiation Therapy for Locally Advanced Non-Small-Cell Lung Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: To investigate the feasibility, toxicity and response rate, of concurrent chemoradiation therapy with paclitaxel/cisplatin in stage III locally advanced non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Between May 1999 and December 2000, 80 patients with stage III NSCLC were enrolled in a prospective protocol. Radiotherapy was given to a total dose of 70.2 Gy (daily fraction of 1.8 Gy for 5 days), over an 8 week period, on the gross tumor volume, combined with chemotherapy. The concurrent chemotherapy consisted of paclitaxel (40 mg/m2) and 20 mg/m2 cisplatin per week for 8 consecutive weeks. All patients received 3-D conformal radiotherapy using CT-simulated planning. Acute toxicities were evaluated by the RTOG scale. The median follow-up period was 16 months, ranging from 3 to 29 months. RESULTS: Of the 80 patients, 71 received treatment per protocol, with minor variation of protocol delivery. The median age of the patients was 60 years. Karnofsky Performance status were 100 and 90 in 62 patients, and 80 and 70 in 9, respectively. Weight loss of less than 5% for 6 months was observed in 22 patients. The response to treatment was evaluated from the radiological findings. Complete and partial responses were observed in 8 and 51 patients, respectively. Ultimately, 82% of patients (included complete responses: 8 cases) obtained more than a partial response. Although, radiation induced esophagitis was the most common treatment related toxicity, occurring in 44 patients (69%), severe radiation esophagitis like, grade 3, was observed in only 3 patients, and the most acute toxicities had completely recovered 1 month following treatment. The overall 2-year actuarial and progression free survivals were 56 and 45%, respectively. CONCLUSION: This combined modality has activity with manageable toxicity and 23 months in mean survival time in patients with stage III NSCLC. A longer follow up will be required to realise the expected higher survival of these results.

Optimal Scheme of Postoperative Chemoradiotherapy in Rectal Cancer: Phase III Prospective Randomized Trial / 대한방사선종양학회지

PURPOSE: To determine the optimal scheme of postoperative chemoradiotherapy in rectal cancer by comparing survival, patterns of failure, toxicities in early and late radiotherapy groups using a phase III randomized prospective clinical trial. MATERIALS AND METHODS: From January 1996 to March 1999, 307 patients with curatively resected AJCC stage II and III rectal cancer were assigned randomly to an 'early (151 patients, arm I)' or a 'late (156 patients, arm II)' and were administered combined chemotherapy (5-FU 375 mg/m2/day, leucovorin 20 mg/ m2, IV bolus daily, for 3 days with RT, 5 days without RT, 8 cycles with 4 weeks interval) and radiation therapy (whole pelvis with 45 Gy/25 fractions/5 weeks). Patients of arm I received radiation therapy from day 1 of the first cycle of chemotherapy and those of arm II from day 57 with a third cycle of chemotherapy. The median follow-up period of living patients was 40 months. RESULTS: Of the 307 patients enrolled, fifty patients did not receive scheduled radiation therapy or chemotherapy. The overall survival rate and disease free survival rate at 5 years were 78.3% and 68.7% in arm I, and 78.4% and 67.5% in arm II. The local recurrence rate was 6.6% and 6.4% ( p=0.46) in arms I and II, respectively, no significant difference was observed between the distant metastasis rates of the two arms (23.8% and 29.5%, p=0.16). During radiation therapy, grade 3 diarrhea or more, by the NCI common toxicity criteria, was observed in 63.0% and 58.2% of the respective arms ( p=N.S.), but most were controlled with supportive care. Hematologic toxicity (leukopenia) greater than RTOG grade 2 was found in only 1.3% and 2.6% of patients in each respective arm. CONCLUSION: There was no significant difference in survival, patterns of failure or toxicities between the early and late radiation therapy arms. Postoperative adjuvant chemoradiation was found to be a relatively safe treatment but higher compliance is needed.

Primary Orbital Lymphoma: A Retrospective Analysis of Results of Radiation Therapy / 대한방사선종양학회지

PURPOSE: This study evaluated the treatment outcomes, patterns of failure, and treatment related complications of primary lymphoma patients who received definitive radiation therapy. MATERIALS AND METHODS: A retrospective analysis was undertaken for 31 patients with primary orbital lymphoma at the Asan Medical Center between February 1991 and April 2001. There were 18 males and 13 females with ages ranging from 3 to 73 years (median, 44 years). The involved sites were 9 conjunctivae, 12 eyelids and 10 other orbits. The histological types were 28 MALT lymphomas (low-grade B-cell lymphoma of mucosa-associated lymphoid tissue type), 1 diffuse large B-cell lymphoma, 1 anaplastic large cell lymphoma and 1 lymphoblastic lymphoma. The Ann Arbor stages were all IE (100%). Ann Arbor stage III or IV patients were excluded from this study. Bilateral orbital involvement occurred in 6 cases. Radiation therapy was given with one anterior port of high energy electrons (6~16 MeV) for the lesions located at the anterior structures like the conjunctivae or eyelids. Lesions with a posterior extension or other orbital lesions were treated with 4 or 6 MeV photons with appropriately arranged portals. In particular, lens blocks composed of lead alloy were used in conjunctival or eyelid lesions. Twelve patients received chemotherapy. The median follow-up period was 53 months. RESULTS: The 5-year overall, cause-specific, and disease-free survival was 91%, 96%, and 80%, respectively. The complete response rate 6 months after radiation therapy was 100%. Local recurrences were observed in 2 patients at 16 and 18 months after completion of radiation treatment. They were salvaged with additional radiation therapy. Two patients developed distant metastases. A MALT lymphoma patient with a lung relapse was successfully salvaged with radiotherapy, but the other lymphoblastic lymphoma patient with bone marrow relapse expired. There were no severe complications but 5 patients developed radiation-induced cataracts and 2 patients developed dry eye. CONCLUSION: Most primary orbital lymphomas consisted of MALT lymphomas. Radiation therapy was a successful treatment modality for orbital lymphoma without any severe complications. In cases of local relapses, radiation therapy is also a very successful salvage treatment modality.

Conjunctival Lymphoma: Retrospective Analysis of the Treatment Result and Complications with Radiation Therapy / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: In order to evaluate the response to radiation therapy and to analyze the patterns of failure, survival and complications, we performed a retrospective analysis of patients with conjunctival lymphoma. MATERIALS AND METHODS: From November 1991 to March 1999, 11 patients were diagnosed as conjunctival lymphoma at Asan Medical Center. Five patients had bilateral involvements, and a total of 16 eyes received radiation therapy. Using 6 to 9 MeV electrons or 4 MV photon beams, all patients were treated with a single anterior field to total doses ranging from 30 Gy to 45 Gy delivered in 10 to 25 fractions. The median follow up period was 57 Months. RESULTS: All patients achieved a complete response with radiation therapy. Two of 16 eyes that were treated (12.5%) developed local recurrence after radiation therapy, however they were salvaged with 30 Gy of reirradiation. The five-year local control was 88.9%. One out of 11 patients (9.9%) developed lung metastasis and received chest irradiation. At the last follow up, one had died of pneumonia and 10 patients were alive without disease evidence. The five-year overall survival rate was 77.8% and 5-year disease free survival was 77.8%. Cataract and dry eye occurred in one patient (9.9%) respectively. CONCLUSION: Radiation therapy is a very effective and safe treatment modality for conjunctival lymphoma. The local control rate of radiotherapy was excellent and complications were acceptable. Radiation therapy is also an effective treatment modality for recurrent conjunctival lymphoma. It generally requires more than three months to achieve complete response following radiation therapy, thus we recommend evaluating the response to radiation therapy at three months after completion of treatment.

Preliminary Results of Stereotactic Radiosurgery Using Stereotactic Body Frame / 대한방사선종양학회지

PURPOSE: To evaluate efficacy and complication of stereotactic radiosurgery using stereotactic body frame. METHODS AND MATERIALS: From December 1997 to June 1999, 11 patients with primary and metastatic tumors were treated with stereotactic radiosurgery using stereotactic body frame(Precision Therapy(TM)). Three patients were treated with primary hepatoma and seven with metastatic tumor from liver, lung, breast, trachea and one with arteriovenous malformation on neck. We used vacuum pillow for immobilization and made skin marker on sternum and tibia area with chest marker and leg marker. Diaphragm control was used for reducing movement by respiration. CT-simulation and treatment planning were performed. Set-up error was checked by CT-Simulator before each treatment. Dose were calculated on the 80~90% isodose of isocenter dose and given consecutive 3 fractions for total dose of 30 Gy (10 Gy/fraction). RESULTS: Median follow-up was 12 months. One patient (9%) showed complete response and four patients (36%) showed partial response and others showed stable disease. Planning target volumes (PTV) ranged from 3 to 111 cc (mean 18.4 cc). Set-up error was within 5 mm in all directions (X, Y, Z axis). There was no complication in all patients. CONCLUSION: In primary and metastatic tumors, stereotactic radiosurgery using stereotactic body frame is very safe, accurate and effective treatment modality.

A Prospective Randomized Trial Comparing the Sequence of Adjuvant Chemotherapy and Radiotherapy following Curative Resection of Stage II, III Rectal Cancer / 대한방사선종양학회지

PURPOSE: To evaluate the side effects, pattern of failure, and survival rate according to the sequence of postoperative adjuvant radiotherapy and chemotherapy, patients with stages II and lll rectal cancer who had undergone curative resection were randomized to early radiotherapy group (arm I) or 'late radiotherapy group (arm II)', then we intend to determine the most effective sequence of the radiotherapy and chemotherapy. MATERIALS AND METHODS: From January 1996 to March 1999, 3 13 patients with curatively resected stages II and III rectal cancer have been randomized to early' or late radiation therapy group and recei ved combined chemotherapy (5-FU 375 mg/m/day, leucovorin 20 mg/m, IV bolus daily D1-5, 8 cycles) and radiation therapy (whole pelvis with 45 Gy/25 fractions/5 weeks). Arm I received radiation therapy from day 1 with first cycle of chemotherapy and arm II received radiation therapy from day 57 with third cycle of chemotherapy after completion of first two cycles. Preliminary analysis was performed with 228 patients registered up to Jun 1998. Two out of the 228 patients were excluded because of double primary cancer. Median follow-up period was 23 months. RESULTS: Local recurrence occurred in 11 patients (9.7%) for arm I and 9 patients (8%) for arm II. There was no significant difference between both groups (p=0.64). However, distant metastasis was found in 22 patients (19.5%) for arm I and 35 patients (31.0%) for arm II and which showed statistically significant difference between the two groups (p=0.046). And neither 3-year disease-free survival (70.2% vs 59.2%, p=0.2) nor overall survival (89.4% vs 88.0%, p=0.47) showed significant differences. The incidence of leukopenia during radiation therapy and chemotherapy was 78.3% and 79.9% respectively but leukopenia more than RTOG grade 3 was only 2.1% and 6.0% respectively. The incidence of diarrhea more than 10 times per day was significantly higher in the patients for arm I than for arm II (71.2% vs 4 1.6%, p=0.02) but this complication was controlled with supportive cares. CONCLUSION: Regardless of the sequence of postoperative adjuvant radiation therapy and chemotherapy a fter curative resection for rectal cancer, local recurrence rate was low with combined chemoradiotherapy. But distant metastasis rate was lower in early radiation therapy group than in late radiation therapy group and the reason is unclear. Most patients completed these treatments without severe complication, so these were thought to be safe treatments but the treatment compliance should be improved.