Acute adverse events of ultra-hypofractionated whole-breast irradiation after breast-conserving surgery for early breast cancer in Japan: an interim analysis of the multi-institutional phase II UPBEAT study

BACKGROUND

The applicability of ultra-hypofractionated (ultra-HF) whole-breast irradiation (WBI) remains unknown in Japanese women. This study aimed to evaluate the safety and efficacy of this approach among Japanese women and report the results of an interim analysis performed to assess acute adverse events (AEs) and determine whether it was safe to continue this study.

METHODS

We enrolled Japanese women with invasive breast cancer or ductal carcinoma in situ who had undergone breast-conserving surgery, were aged ≥ 40 years, had pathological stages of Tis-T3 N0-N1, and had negative surgical margins. Ultra-HF-WBI was delivered at 26 Gy in five fractions over one week. When the number of enrolled patients reached 28, patient registration was paused for three months. The endpoint of the interim analysis was the proportion of acute AEs of grade ≥ 2 (Common Terminology Criteria for Adverse Events v5.0) within three months.

RESULTS

Of the 28 patients enrolled from seven institutes, 26 received ultra-HF-WBI, and 2 were excluded due to postoperative infections. No AEs of grade ≥ 3 occurred. One patient (4%) experienced grade 2 radiation dermatitis, and 18 (69%) had grade 1 radiation dermatitis. The other acute grade 1 AEs experienced were skin hyperpigmentation (n = 10, 38%); breast pain (n = 4, 15%); superficial soft tissue fibrosis (n = 3, 12%); and fatigue (n = 1, 4%). No other acute AEs of grade ≥ 2 were detected.

CONCLUSIONS

Acute AEs following ultra-HF-WBI were within acceptable limits among Japanese women, indicating that the continuation of the study was appropriate.

Application and limitation of radiomics approach to prognostic prediction for lung stereotactic body radiotherapy using breath-hold CT images with random survival forest: A multi-institutional study

PURPOSE

To predict local recurrence (LR) and distant metastasis (DM) in early stage non-small cell lung cancer (NSCLC) patients after stereotactic body radiotherapy (SBRT) in multiple institutions using breath-hold computed tomography (CT)-based radiomic features with random survival forest.

METHODS

A total of 573 primary early stage NSCLC patients who underwent SBRT between January 2006 and March 2016 and met the eligibility criteria were included in this study. Patients were divided into two datasets: training (464 patients in 10 institutions) and test (109 patients in one institution) datasets. A total of 944 radiomic features were extracted from manually segmented gross tumor volumes (GTVs). Feature selection was performed by analyzing inter-segmentation reproducibility, GTV correlation, and inter-feature redundancy. Nine clinical factors, including histology and GTV size, were also used. Three prognostic models (clinical, radiomic, and combined) for LR and DM were constructed using random survival forest (RSF) to deal with total death as a competing risk in the training dataset. Robust models with optimal hyper-parameters were determined using fivefold cross-validation. The patients were dichotomized into two groups based on the median value of the patient-specific risk scores (high- and low-risk score groups). Gray's test was used to evaluate the statistical significance between the two risk score groups. The prognostic power was evaluated by the concordance index with the 95% confidence intervals (CI) via bootstrapping (2000 iterations).

RESULTS

The concordance indices at 3 yr of clinical, radiomic, and combined models for LR were 0.57 [CI: 0.39-0.75], 0.55 [CI: 0.38-0.73], and 0.61 [CI: 0.43-0.78], respectively, whereas those for DM were 0.59 [CI: 0.54-0.79], 0.67 [CI: 0.54-0.79], and 0.68 [CI: 0.55-0.81], respectively, in the test dataset. The combined DM model significantly discriminated its cumulative incidence between high- and low-risk score groups (P < 0.05). The variable importance of RSF in the combined model for DM indicated that two radiomic features were more important than other clinical factors. The feature maps generated on the basis of the most important radiomic feature had visual difference between high- and low-risk score groups.

CONCLUSIONS

The radiomics approach with RSF for competing risks using breath-hold CT-based radiomic features might predict DM in early stage NSCLC patients who underwent SBRT although that may not have potential to predict LR.

Risk factors for severe gastrointestinal toxicity in patients receiving palliative radiotherapy for metastatic bone tumors: association with the use of molecular-targeted agents

This study aimed to investigate whether the use of molecular-targeted agents could affect gastrointestinal (GI) toxicity in palliative radiotherapy (RT) for metastatic bone tumors in the abdominopelvic region. We collected data of patients who received palliative RT for bone metastases in the abdominopelvic region between 2013 and 2014 from six institutions. Data of 395 patients were collected and184 patients received molecularly targeted therapy, of whom 80 received vascular endothelial growth factor (VEGF)-targeted agents. For 556 lesions, 410 sessions of irradiation were undergone. GI toxicity of ≥G3 was observed in 3.8% of patients. The incidence rates of ≥G3 GI toxicity in patients without targeted agents use, in those using VEGF-targeted agents and in those using non-VEGF-targeted agents were 3.8, 7.5 and 1.0%, respectively. Regarding risk factors of the occurrence of ≥G3 GI toxicity, univariate analysis in all patients showed that a history of abdominopelvic surgery was a significant risk factor (P = 0.01), and the use of VEGF-targeted agents showed a trend of high incidence (P = 0.06). In patients using VEGF-targeted agents, both univariate and multivariate analysis showed that combined anticoagulant use (P = 0.03 and 0.01) and agent use between 1 week before and after RT (P = 0.046 and 0.03) were significant risk factors. In conclusion, the history of abdominopelvic surgery was associated with ≥G3 GI toxicity and the use of VEGF-targeted agents showed a trend for high incidence. When using VEGF-targeted agents, caution should be exercised in the combined use of anticoagulants and in the agent use between 1 week before and after RT.

The Use of External-beam Radiotherapy for Muscle-invasive Bladder Cancer in Elderly or Medically-fragile Patients

AIM

To evaluate the clinical results of external-beam radiotherapy (EBRT) for muscle-invasive bladder cancer (MIBC) in elderly or medically-fragile patients.

PATIENTS AND METHODS

Twenty-five consecutive patients with MIBC (cT2-4N0-1M0) receiving EBRT were retrospectively analyzed. Their median age was 82 years. Radiotherapy median dose was 60 Gy administered in 30 fractions.

RESULTS

Median follow-up period was 14.7 months. Median overall survival (OS) and progression-free survival (PFS) were 14.7 months and 7.8 months, respectively. The OS, cause-specific survival (CSS), and PFS rates at 1-year were 56.0%, 68.5%, and 40.0%, respectively. The local progression-free rates (LPFR) at 6 months and 1 year were 89.3% and 59.5%, respectively. Performance status 3 was a significantly unfavorable factor for OS, CSS, and progression-free survival; clinical N stage was a significantly unfavorable factor for progression-free survival; and lower irradiation dose (≤50.4 Gy) was a significantly unfavorable factor for LPFR.

CONCLUSION

EBRT for elderly or medically-fragile patients is feasible, and achieves acceptable local progression-free status.

Comparison of the outcomes of stereotactic body radiotherapy and surgery in elderly patients with cT1-2N0M0 non-small cell lung cancer

BACKGROUND

This study aimed to compare the outcomes of stereotactic body radiotherapy (SBRT) and surgery in elderly patients with cT1-2N0M0 non-small cell lung cancer (NSCLC).

METHODS

Elderly patients (≥75 years) with cT1-2 (≤5 cm) N0M0 NSCLC who were treated with SBRT (n=35) or surgery (n=183) between January 2001 and December 2011 were analyzed.

RESULTS

The following radiation doses were administered: 48 Gy/4-6 fractions in 12 patients; 50 Gy/4-5 fractions in 20; and 60 Gy/8 fractions in 3. The following surgical methods were performed: pneumonectomy in 2 patients, lobectomy in 154, segmentectomy in 23, and wedge resection in 4. Patients in the SBRT group had a higher mean age, a worse performance status, and a lower percentage of forced expiratory volume in 1.0 s than those in the surgery group. The overall 5-year survival rates were 43.8% and 67.6% for the SBRT and surgery groups, respectively (p=0.057, log-rank test). Regarding tumor diameter, patients in the surgery group survived significantly longer than did those in the SBRT group (>20-mm tumors, p=0.027; >30-mm tumors p=0.043), whereas survival did not differ significantly between the groups for ≤20-mm tumors (p=0.982). Multivariate analysis confirmed the improved survival in the surgery group compared to the SBRT group for all tumors (p=0.034) and for >20-mm tumors (p=0.016).

CONCLUSIONS

Post-therapeutic survival among elderly patients might be better with surgery than with SBRT in NSCLC patients with tumors >20 mm.

Efficacy of intraoperative radiotherapy targeted to the abdominal lymph node area in patients with esophageal carcinoma

We investigated whether intraoperative radiotherapy (IORT) during curative surgery for esophageal carcinoma is useful or not. The cases of 117 patients diagnosed with thoracoabdominal esophageal carcinoma who underwent curative surgery between 1986 and 2007 were reviewed: 72 patients received IORT (IORT group) and 45 did not (non-IORT group). Upper abdominal lymphadenectomy was performed in 115 patients (98.5%). Seventy patients (59.8%) received chemotherapy and 80 patients (68.4%) received external radiotherapy. IORT encompassed the upper abdominal lymph node area. A single-fraction dose of 20-30 Gy was delivered using high-energy electrons. Median follow-up duration for patients was 7.4 years. The 5-year overall survival rate did not significantly differ between the IORT and non-IORT groups. However, the 5-year abdominal control rate was significantly higher in the IORT group (89.2%) than in the non-IORT group (72.9%; P = 0.022). We next focused on a patient subgroup with a primary lesion in the lower thoracic or abdominal esophagus or measuring >6 cm in length since this subgroup is probably at high risk of upper abdominal lymph node metastasis. Of the 117 patients, 75 belonged to this subgroup, and among them 45 received IORT. Both univariate and multivariate analysis revealed the survival rate was significantly higher in patients who received IORT than in those who did not (P = 0.033 univariate; 0.026 multivariate). There were no obvious perioperative complications solely attributed to IORT. IORT for esophageal carcinoma will likely be effective for patients with a primary lesion in the lower thoracic or abdominal esophagus, or with a long lesion.

Long-term follow-up of a randomized Phase II study of cisplatin/5-FU concurrent chemoradiotherapy for esophageal cancer (KROSG0101/JROSG021)

OBJECTIVE

Long-term survival and late toxicities of a randomized Phase II study of chemoradiotherapy for esophageal cancer were analyzed.

METHODS

Eligible patients were <75 years old and performance status 0-2, and had Stages II-IVA esophageal cancer. For arm A (short-term infusion), cisplatin 70 mg/m(2) Days 1 and 29 and 5-fluorouracil 700 mg/m(2) Days 1-5 and 29-33 were given concurrently with radiotherapy of 60 Gy/30 fr/7 weeks (1 week split). For arm B (protracted infusion), cisplatin 7 mg/m(2) Days 1-5, 8-12, 29-33 and 36-40, and 5-fluorouracil 250 mg/m(2) Days 1-14 and 29-42 were given with the same radiotherapy. Two cycles of consolidation cisplatin/5-fluorouracil chemotherapy were given to both arms.

RESULTS

Between 2001 and 2006, 91 patients were enrolled; 46 were randomized to arm A, and 45 to arm B. The 2- and 5-year overall survival rates for arm A were 46 and 35% (95% confidence interval: 22-48%), while those for arm B were 44 and 22% (11-35%), respectively. Excluding four patients with early death, seven (17%) patients in arm A and eight (18%) in arm B showed late toxicities of Grade 3 or more. Most of the toxicities were cardiac or pleural toxicities. Patients with severe late toxicities often had coexistent hypothyroidism. There were three patients with a secondary malignancy possibly related to treatment.

CONCLUSIONS

Low-dose protracted infusion chemotherapy with radiotherapy is not superior to full-dose short-term infusion chemotherapy with radiotherapy for esophageal cancer. Late toxicities, including cardiac and pleural toxicities, hypothyroidism and secondary malignancy, should be carefully monitored.

Clinical practice and outcome of radiotherapy for esophageal cancer between 1999 and 2003: the Japanese Radiation Oncology Study Group (JROSG) Survey

BACKGROUND

To determine the clinical results of radiotherapy (RT) for esophageal cancer in Japan.

MATERIALS AND METHODS

A questionnaire-based survey was conducted for esophageal cancer treated by definitive RT between 1999 and 2003. Clinical results of definitive RT for patients were collected from 9 major institutions. Only patients with good performance status (PS 0-2) who received a total dose of 50 Gy or more were included. Patients were classified into three groups: (A) stage I, (B) resectable stages II-III, (C) unresectable stages III-IVA. For group A, all patients treated by RT alone or chemo-radiotherapy (CRT) were included. For groups B and C, only those treated by CRT were included.

RESULTS

In total, 167 patients were included in group A, 239 in group B, and 244 in group C. Approximately half of the patients in group A were treated by CRT. The median total RT dose ranged from 60 to 66 Gy. The median and range of the 5-year overall survival rates were 56% (48-83%) for group A, 29% (12-52%) for group B, and 19% (0-31%) for group C, respectively. A wide disparity in overall survival rates was noted among the institutions. A significant correlation between the number of patients treated per year and the 5-year overall survival rate was noted for groups B and C (both p < 0.05).

CONCLUSION

Although the overall survival rates for stage I esophageal cancer were excellent, a significant disparity in survival rates was noted among the institutions for stage II-IVA tumors treated by CRT.

Intraoperative radiotherapy for resected pancreatic cancer: a multi-institutional retrospective analysis of 210 patients

PURPOSE

To retrospectively analyze the results of intraoperative radiotherapy (IORT) with or without external beam radiotherapy (EBRT) for resected pancreatic cancer.

METHODS AND MATERIALS

The records of 210 patients treated with gross complete resection (R0: 147 patients; R1: 63 patients) and IORT with or without EBRT were reviewed. One hundred forty-seven patients (70.0%) were treated without EBRT and 114 patients (54.3%) were treated in conjunction with chemotherapy. The median doses of IORT and EBRT were 25 Gy (range, 20-30 Gy) and 45 Gy (range, 20-60Gy), respectively. The median follow-up of the surviving 62 patients was 26.3 months (range, 2.7-90.5 months).

RESULTS

At the time of this analysis, 150 of 210 patients (71.4%) had disease recurrences. Local failure was observed in 31 patients (14.8%), and the 2-year local control rate in all patients was 83.7%. The median survival time and the 2-year actuarial overall survival (OS) in all 210 patients were 19.1 months and 42.1%, respectively. Patients treated with IORT and chemotherapy had a significantly more favorable OS than those treated with IORT alone (p = 0.0011). On univariate analysis, chemotherapy use, degree of resection, carbohydrate antigen 19-9, and pathological N stage had a significant impact on OS and on multivariate analysis; these four factors were significant prognostic factors. Late gastrointestinal morbidity of NCI-CTC Grade 4 was observed in 7 patients (3.3%).

CONCLUSION

IORT yields an excellent local control rate for resected pancreatic cancer with few frequencies of severe late toxicity, and IORT combined with chemotherapy confers a survival benefit compared with that of IORT alone.

Patterns of Care Study of Breast-conserving Therapy in Japan: Comparison of the Treatment Process between 1995 1997 and 1999 2001 Surveys

BACKGROUND

The Japan Patterns of Care Study (JPCS) conducted two national surveys to identify changes associated with the treatment process of care for patients undergoing breast-conserving therapy (BCT). Between the two national surveys, the Japanese Breast Cancer Society published its treatment guideline for BCT.

METHOD

The first survey collected data on 865 patients treated between 1995 and 1997 (JPCS-1), and the second on 746 patients treated between1999 and 2001 (JPCS-2) by extramural audits.

RESULTS

There was a shift to an older age distribution in JPCS-2 compared with JPCS-1. In JPCS-2, the average patient age was 53.9 compared with 51.5 in JPCS-1 (P < 0.001). There was a reduction in the extent of breast surgery and the proportion of the patients who received quadrantectomy was 57.0% in JPCS-1 and 30.3% in JPCS-2 (P < 0.001). In JPCS-2, a cast or shell for immobilization was used at a significantly higher rate of 52.9% compared with 32.6% for JPCS-1 (P < 0.001). The rate of boost irradiation was increased in JPCS-2, especially for patients with a positive surgical margin; it was significantly increased to 83.5% in JPCS-2 compared with 53.9% in JPCS-1 (P < 0.001).

CONCLUSIONS

The second survey revealed a rapid change in the trend of the treatment of BCT in Japan and represented high compliance of the treatment guideline for BCT published by the Japanese Breast Cancer Society (JBCS) in 1999.

Results of radiation therapy combined with neoadjuvant hormonal therapy for stage III prostate cancer: comparison of two different definitions of PSA failure

BACKGROUND

We herein report the clinical outcome of radical radiation therapy combined with neoadjuvant hormonal therapy (NHT) for stage III (International Union Against Cancer [UICC] 1997: UICC 97) prostate cancer. Prostate-specific antigen (PSA) failure-free survival was assessed according to two different definitions, and the appropriateness of each definition is discussed.

METHODS

Between October 1997 and December 2000, 27 patients with stage III prostate cancer were enrolled in this study. The median pretreatment PSA level was 29 ng/ml (range, 7.4-430 ng/ml). The Gleason score (GS) was 7 or more in 22 patients (81%). All patients received 3 months of NHT with a luteinizing hormone-releasing hormone (LH-RH) analogue, in combination with an antiandrogen (flutamide), given during the first 2 weeks, followed by 70-Gy external-beam radiation therapy (EBRT) in 35 fractions. The initial 46 Gy was given with a four-field technique, while the remainder was given with a dynamic conformal technique. No adjuvant hormonal therapy (AHT) was given.

RESULTS

The median follow-up time was 63 months. PSA levels decreased to the normal range (<4 ng/ml) after irradiation in all but one patient. The 5-year PSA failure-free survival was 34.8% according to the American Society for Therapeutic Radiology and Oncology (ASTRO) definition and it was 43.0% according to the "nadir plus 2" definition. Discordance of the results between the two definitions was seen in two patients. The 5-year overall and cause-specific survivals were 83.0% and 93.3%, respectively. No severe acute or late adverse effects were observed.

CONCLUSION

Seventy Gy of EBRT following 3 months of NHT produced therapeutic results comparable to those reported in other studies which used long-term AHT. The value of long-term AHT for Japanese men should be tested in a clinical trial.

The patterns of care study for breast-conserving therapy in Japan: Analysis of process survey from 1995 to 1997

PURPOSE

To present the results of a process survey on breast-conserving therapy (BCT) in Japan from 1995 to 1997.

METHODS AND MATERIALS

From September 1998 to December 1999, data on the treatment process of 865 randomly selected BCT patients were collected by extramural audits.

RESULTS

For primary surgery, wide excision or tumorectomy was performed in 372 patients (43.0%), and quadrantectomy or segmental mastectomy was performed in 493 patients (57%). The extent of axillary dissection was equal or beyond Level II in 590 patients (68.2%). Systemic chemotherapy was administered to 103 of 160 node-positive patients (64.4%) and 180 of 569 node-negative patients (31.6%). Tamoxifen was administered to 234 of 323 hormone receptor-positive patients (72.5%) and 68 of 130 hormone receptor-negative patients (52.3%). Photon energy of 10 MV was administered for whole breast irradiation in 38 patients (4.4%) without bolus.

CONCLUSIONS

The extent of surgical resection for BCT was large in Japan. Pathologic assessment and the technique of radiation therapy were apparently suboptimal in some cases. Information on prognostic/predictive factors was not fully utilized to individualize systemic adjuvant therapy. Establishment and widespread use of guidelines for BCT for in Japan are desirable. Repeated surveys will demonstrate how such guidelines affect clinical practices.

Treatment planning of stereotactic radiotherapy for solitary lung tumor

PURPOSE

To analyze the stereotactic radiotherapy (SRT) plans in terms of internal target volume (ITV) and organs at risk (OARs).

METHODS AND MATERIALS

Treatment planning and dose distributions were analyzed using dose-volume histograms (DVHs) of ITV and OARs in 37 patients, who were treated for a solitary lung tumor with SRT. The stereotactic body frame (SBF) was used for immobilization and accurate setup. Prescription dose was 48 Gy in four fractions at the isocenter.

RESULTS

Use of SBF limits the extent of the noncoplanar beam directions to prevent a collision with the Linac gantry. DVH analyses showed that the homogeneity index, defined as the ratio of maximum and minimum dose to ITV, ranged from 1.03 to 1.25 (mean, 1.12). The volume irradiated with 20 Gy or more (V(20)) of the lung ranged from 0.3 to 11.6% (mean, 4.4%) of the whole lung volume. The maximum dose to the other OARs ranged from 0 to 11.8 Gy (mean, 0.5-2.7) per fraction. No clinically significant complications were encountered.

CONCLUSIONS

Despite the limitation of the beam arrangement, a homogeneous target dose distribution, while avoiding high doses to normal tissues, was obtained.

18F-FDG and11C-methionine PET for evaluation of treatment response of lung cancer after stereotactic radiotherapy

This study was performed to investigate the feasibility of FDG- and L-[methyl-11C]methionine (Met)-PET for the follow up of lung cancer after stereotactic radiotherapy (SRT). Nine patients (pt) with solitary lung cancer underwent SRT. Met- and FDG-PET studies were performed one week before SRT and from one week to 8 months after SRT. Responses to SRT were complete in 2 pt and partial in 7 pt. Met- and FDG-PET scan showed high tracer uptake in all tumors before SRT. After SRT, standardized uptake values (SUV) of FDG and Met changed concordantly. Both decreased with time in 5 pt but did not decrease steadily in 4 pt, where 2 pt showed an increase at 1 to 2 weeks after SRT and 2 pt showed an increase at more than 3 months after SRT. The former appears to reflect the acute reaction to SRT and the latter radiation-induced pneumonitis. Although the addition of Met-PET did not provide additional information over FDG-PET, FDG- and Met-PET could be used to evaluate the treatment effect of SRT.

Evaluation of Lung Injury after Three-dimensional Conformal Stereotactic Radiation Therapy for Solitary Lung Tumors: CT Appearance

PURPOSE

To evaluate the computed tomographic (CT) appearance of tumors and lung injury in patients who have undergone stereotactic radiation therapy (SRT) for solitary lung tumors.

MATERIALS AND METHODS

Twenty-seven patients with primary lung cancer and four with metastatic lung cancer who underwent SRT for solitary lung tumors were enrolled for evaluation. SRT was delivered by using a three-dimensional conformal technique with a stereotactic body frame. A total dose of 48 Gy was administered in four fractions during a period of 2 weeks. After SRT, follow-up CT images were obtained every 2-3 months. Radiation-induced pulmonary injuries were classified into four patterns on CT images. The minimal lung dose to areas demonstrating pulmonary injury at CT was evaluated, and the correlation between the dose and the percentage volume of the whole lung irradiated by more than 20 Gy in total (V20) was assessed by using Spearman rank correlation.

RESULTS

Tumor shrinkage continued for 2-15 months after SRT. Asymptomatic changes in the irradiated lung were noted at CT in all patients within 2-6 months (median, 4 months) after SRT. As the pattern at pulmonary CT changed, patchy consolidation was more predominantly seen as an acute change than were slight homogeneous increase in opacity, discrete consolidation, or solid consolidation; solid consolidation was the more predominantly seen late change. The minimal lung dose to the area demonstrating pulmonary injury in each patient ranged between 16 and 36 Gy (median, 24 Gy). The dose was significantly (P <.001) inversely correlated with the V20 in each patient.

CONCLUSION

The reaction to SRT of the lungs seems similar to the reaction to conventional radiation therapy.

[Three-dimensional conformal radiotherapy for extracranial tumors using a stereotactic body frame]

This paper was reviewed to evaluate the feasibility of three-dimensional (3-D) conformal radiotherapy for extracranial tumors, especially for solitary lung tumors using a stereotactic body frame. To extend the technique of stereotactic irradiation for intracranial tumors, accurate body fixation and regulation of internal target motion are essential. In our study, a stereotactic body frame was used, and daily setup accuracy was verified. As a result, its setup accuracy was maintained within 0-8.5 mm (Ave=2.5mm). In our initial clinical experiences for thirty-two patients with 6-10 non-coplanar static beams, forty or 48 Gy was irradiated. During the follow-up of 4-27 (Average=11) months, twenty-nine (94%) tumors were locally controlled without any symptomatic complications. Recently, respiratory-gated irradiation systems, CT-linac systems, a real-time tumor tracking system, Cyber-knife, and C-arm linac were developed. With all these techniques, stereotactic irradiation for extracranial tumors are future direction of three-dimensional conformal radiotherapy.

Clinical evaluation of dynamic arc conformal radiotherapy for paraaortic lymph node metastasis

PURPOSE

This study was performed to evaluate the efficacy and safety of dynamic arc conformal radiotherapy, a simple intensity modulated radiation therapy (IMRT), for the treatment of paraaortic lymph node metastases.

MATERIALS AND METHODS

Twenty-nine patients with paraaortic lymph node metastases were enrolled in this study. The total planned dose was 55-60 Gy. A computed tomography (CT) simulator was used in the treatment planning.

RESULTS

The total radiation dose delivered was 50-63.4 Gy (median 60 Gy). Sixteen of 29 patients showed local tumor shrinkage on CT, and the 2 year in-field recurrence free survival rate was 58%. Acute Grade 1 and Grade 2 gastrointestinal disorders occurred in 31% and 17%, respectively, and acute Grade 2 liver dysfunction occurred in 7%. As a late complication, Grade 1 and Grade 2 liver dysfunction occurred in six patients (21%) and five patients (17%), respectively. There was no renal dysfunction or myelopathy detected.

CONCLUSION

Dynamic arc conformal radiotherapy, a simple IMRT, is a safe and effective treatment method for paraaortic lymph node metastasis.

Clinical outcomes of 3D conformal hypofractionated single high-dose radiotherapy for one or two lung tumors using a stereotactic body frame

PURPOSE

This study was performed to evaluate the clinical outcomes of three-dimensional (3D) conformal hypofractionated single high-dose radiotherapy for one or two lung tumors using a stereotactic body frame.

MATERIALS AND METHODS

Forty patients who were treated between July 1998 and November 2000 and were followed for >10 months were included in this study. Of the 40 patients, 31 had primary lung cancer and 9 had metastatic lung cancer. The primary lung cancer was staged as T1N0M0, T2N0M0, and T3N0M0 in 19, 8, and 4 patients, respectively. The primary sites of metastatic lung cancer were the colon in 4, tongue in 2, and osteosarcoma, lung cancer, and hepatocellular carcinoma in 1 each. 3D treatment planning was performed to maintain the target dose homogeneity within 15% and to decrease the irradiated lung volume from >20 Gy to <25%. All patients were irradiated using a stereotactic body frame and received 4 times 10-12 Gy single high-dose radiation at the isocenter during a period of 5-13 days (median 12).

RESULTS

The initial 3 patients received 40, and the remaining 37 patients received 48 Gy after dose escalation. Of the 33 tumors followed >6 months, 6 tumors (18%) disappeared completely after treatment. Twenty-five tumors (76%) decreased in size by 30% or more after treatment. Therefore, 31 tumors (94%) showed a local response. During the follow-up of 4-37 months (median 19), no pulmonary complications greater than National Cancer Institute-Common Toxicity Criteria Grade 2 were noted. Of the 16 patients with histologically confirmed T1N0M0 primary lung cancer who received 48 Gy, all tumors were locally controlled during the follow-up of 6-36 months (median = 19). In 9 tumors with lung metastases that were irradiated with 48 Gy in total, 2 tumors did not show a local response. Finally, 3 tumors (33%) with lung metastases relapsed locally at 6-12 months (median 7) after treatment during the follow-up of 3-29 months (median 18).

CONCLUSION

3D conformal hypofractionated single high-dose radiotherapy of 48 Gy in 4 fractions using a stereotactic body frame was useful for the treatment of lung tumors.

Postoperative radiotherapy for intracranial ependymoma: analysis of prognostic factors and patterns of failure

The long-term results of external beam radiotherapy following surgical resection in patients with intracranial ependymomas were evaluated to identify the prognostic factors and the pattern of recurrence. Between June 1961 and January 1999, 48 patients with intracranial ependymoma were treated with external beam irradiation with >40 Gy following surgery. Total doses of 40.5-63.4Gy were delivered to the tumor site in 22-46 fractions over 33-101 days. Six patients with spinal deposit or positive cerebrospinal fluid cytology received whole spinal axis irradiation, and 4 patients received prophylactic spinal irradiation. The median follow-up of surviving patients was 110 months. The 10-year overall and relapse-free survival rates were 47% and 42%, respectively. In multivariate analysis, female gender, lower tumor grade and total resection were found to be associated with better relapse-free survival. Twenty of 26 recurrences developed at the primary tumor site (inside the irradiation field), two at the unirradiated cerebellum and spinal cord, and four at the spinal cord without intracranial failure. Only one of 34 patients with supratentorial tumors developed isolated spinal metastasis, whereas 3 of 14 patients with infratentorial tumors did so. Regarding the late neurotoxicity of radiotherapy, one of the 15 long-term (>4 years) survivors whose psychosocial status could be evaluated showed marked cognitive impairment. It was suggested that the use of new treatment strategies to improve local control would be warranted, and that prophylactic whole spinal axis irradiation appeared to be of more benefit in patients with infratentorial tumors than in those with supratentorial tumors.

The effectiveness of an immobilization device in conformal radiotherapy for lung tumor: reduction of respiratory tumor movement and evaluation of the daily setup accuracy

PURPOSE

To evaluate the daily setup accuracy and the reduction of respiratory tumor movement using a body frame in conformal therapy for solitary lung tumor.

METHODS AND MATERIALS

Eighteen patients with a solitary lung tumor underwent conformal therapy using a body frame. The body shell of the frame was shaped to the patient's body contour. The respiratory tumor movement was estimated using fluoroscopy, and if it was greater than 5 mm, pressure was applied to the patient's abdomen with the goal of minimizing tumor movement. CT images were then obtained, and a treatment planning was made. A total dose of 40 or 48 Gy was delivered in 4 fractions. Portal films were obtained at each treatment, and the field displacements between them and the simulation films were measured for daily setup errors. The patients were repositioned if the setup error was greater than 3 mm. Correlations were analyzed between patient characteristics and the tumor movement, or the tumor movement reduction and the daily setup errors.

RESULTS

Respiratory tumor movement ranged from 0 to 20 mm (mean 7.7 mm). The abdominal press reduced the tumor movement significantly from a range of 8 to 20 mm to a range of 2 to 11 mm (p = 0.0002). Daily setup errors were within 5 mm in 90%, 100%, and 93% of all verifications in left-right, anterior-posterior, and cranio-caudal directions, respectively. Patient repositioning was performed in 25% of all treatments. No significant correlation was detected between patient characteristics and tumor movement, tumor movement reduction, and the daily setup errors.

CONCLUSIONS

The abdominal press was successful in reducing the respiratory tumor movement. Daily setup accuracy using the body frame was acceptable. Verification should be performed at each treatment in hypofractionated conformal therapy.

The use of a permanent magnetic resonance imaging system for radiotherapy treatment planning of bone metastases

PURPOSE

To evaluate the usefulness of magnetic resonance (MR) imaging-based radiotherapy treatment planning (RTTP) for bone metastases in clinical applications.

METHODS AND MATERIALS

MR imaging-based RTTP was carried out for 28 patients with bone metastases using a permanent magnetic MR unit. Twenty-three patients received MR imaging-assisted X-ray simulation, and five underwent MR simulation. In MR imaging-assisted X-ray simulation, the radiation fields defined by an X-ray simulator were modified based on MR information scanned in the exact treatment position using MR skin markers. In MR simulation, both isocenter position and field size were determined on MR images and projected onto the patient's skin.

RESULTS

All lesions unclear on other imaging modalities could be clearly identified on MR imaging. Of the 23 patients receiving MR imaging-assisted X-ray simulation, modification of the original radiation field was necessary in 14 patients (extended in 9, reduced in 4, and completely changed in 1). In MR simulation, appropriate radiation fields could be easily and quickly determined using MR imaging.

CONCLUSION

Methods for MR imaging-based RTTP were developed and clinically implemented for patients with bone metastases, and they were shown to be useful for improving the accuracy of the tumor location. They would provide better therapeutic/palliative benefit to particular patients with bone metastases and could also be applied to other lesions in the future.

Reproducibility of geometric distortion in magnetic resonance imaging based on phantom studies

BACKGROUND AND PURPOSE

Image distortion is one of the major drawbacks of magnetic resonance (MR) imaging for use in radiotherapy treatment planning (RTTP). In this study, the reproducibility of MR imaging distortion was evaluated by repeated phantom measurements.

MATERIALS AND METHODS

A grid-pattern acrylic phantom was scanned with a 0.2-Tesla permanent magnetic unit. We repeated a series of scans three times to evaluate the reproducibility of the distortion. In each series, co-ordinates at 432 intersections of the grid were measured for both T1- and T2-weighted spin-echo (SE) pulse sequences. Positional displacements and their variations at the intersections were calculated.

RESULTS

Averages of the displacements were distributed between 1.58 and 1.74 mm, and maximum values (MAX) between 12.6 and 15.0 mm. Within 120 mm of the image center, the average values ranged from 0.73 to 0.80 mm, and from 3.4 to 5.0 mm for MAX. The absolute values of the positional variations among three series were distributed between 0.41 and 0.88 mm for average values, and between 1.4 and 4.5 mm for MAX.

CONCLUSIONS

The positional variations were mostly within 3 pixels, and most of the positional displacements within the radius of 120 mm of the image center were 2 mm or less. Therefore, it will be possible to use this MR system in RTTP under limited situations, although careful applications are required for RTTP of the body. The development of a computer program to correct image distortion is expected.

Transverse instability of solitary waves in the generalized kadomtsev-petviashvili equation

The linear stability of planar solitary waves with respect to long-wavelength transverse perturbations is studied in the framework of the generalized Kadomtsev-Petviashvili equation. It is newly discovered that for some nonlinearities in this family, the solitary waves could be transversely unstable even in a medium with negative dispersion. In the case of positive dispersion, they are found to be always unstable.

Biochemical markers of bone turnover during hormone replacement therapy

OBJECTIVE

To assess the clinical usefulness of bone turnover markers, including serum osteocalcin (OC), urinary pyridinoline (Pyr) and deoxypyridinoline (D-Pyr), in monitoring and predicting bone response to hormone replacement therapy (HRT).

METHOD

The relationships between baseline levels or changes in markers and change in lumbar bone mineral density were examined in 21 surgically-induced postmenopausal women.

RESULTS

Levels of OC, Pyr and D-Pyr in the estrogen effective group (responders) significantly decreased during HRT and baseline levels of Pyr and D-Pyr in responders were significantly higher than those in premenopausal women.

CONCLUSION

Bone turnover markers were useful in monitoring the bone effect of HRT and baseline levels of markers reflect subsequent bone response to HRT.

Radiotherapy combined with transcatheter arterial infusion chemotherapy for locally advanced cervical cancer

Twenty-four patients with locally advanced cervical cancer were treated with radiation therapy (RT) and transcatheter arterial infusion (TAI) chemotherapy, while 22 patients were treated with RT alone. RT consisted of a combination of external irradiation and high-dose-rate intracavitary brachytherapy. TAI therapy consisted of two sessions using cisplatin and pirarubicin, performed concurrently during the periods of external irradiation. The local-regional control rates at 1 year for the patients treated with RT plus TAI and for those treated with RT alone were 87.5% and 58.3%, respectively (p < 0.05). The 3-year cause-specific survival (CSS) rates for RT plus TAI, and RT alone were 67.1% and 55.9%, respectively (p = n.s.). The 3-year CSS rate for the 14 patients treated with RT and TAI who had well- or moderately differentiated squamous cell carcinoma without pelvic lymph node swelling was 100%, while that for the 19 patients with the same background treated with RT alone was 49% (p < 0.01). Radiation therapy combined with TAI appears to be an effective and safe treatment modality for patients with locally advanced cervical cancer.

[Bone mineral content in premenopausal women treated with gonadotropin-releasing hormone analogue]

To assess bone metabolism during treatment with gonadotropin-releasing hormone analogue (GnRHa), serum osteocalcin (BGP), alkaline phosphatase (ALP), parathyroid hormone (PTH), calcitonin (CT), calcium (Ca) and phosphorus (P) were determined before and after 6 months of GnRHa treatment in 15 premenopausal women with clinically diagnosed endometriosis. The bone mineral content (BMC) of the lumbar spine (L3) was measured by single energy quantitative computed tomography in 9 women, and in 6 of these 9 women microdensitometry was performed simultaneously during the treatment. BMC decreased significantly to 92.5 +/- 6.8% (mean +/- SD) of the pretreatment value after 6 months of treatment. On the other hand, microdensitometry revealed no significant change during treatment. Serum BGP and ALP were significantly higher after 6 months of treatment than before treatment, indicating an increase in bone formation. These data indicate that the GnRHa treatment induces an increase in bone turnover and a significant bone loss.

[Bone mass and biochemical parameters in metabolic bone diseases]

We studied the relationship between the bone mass and biochemical parameters in 175 normal premenopausal, 72 normal postmenopausal and osteoporotic postmenopausal women, between 20 and 88 years old, and in 40 patients with hyperthyroidism, and 23 patients with primary hyperparathyroidism, between 13 and 64 years old. The bone mineral density (BMD) of the spine (L2-L4) and proximal femur (femoral neck) was measured by dual-energy X-ray absorptiometry using a QDR-1000, Hologic. The bone mineral content (BMC) of the radius was measured by single photon absorptiometry (SPA) using a model 2780, Norland. Serum PTH, BGP and calcitonin (CT) were determined by radioimmunoassay. The BMD of the spine (L2-L4), and the proximal femur in postmenopausal women were negatively correlated with age. The mean BMD in patients with postmenopausal osteoporosis was significantly lower than that in normal postmenopausal women. In postmenopausal women, age was positively correlated with BGP, PTH, CT and negatively correlated with P. In patients with osteoporosis, the BMD of the spine was negatively correlated with serum BGP. The BMC of radius in patients with hyperthyroidism decreased significantly compared with that in the controls, and was negatively correlated with F-T3. The BMC of the radius in patients with primary hyperparathyroidism was significantly lower than that in the controls, and was negatively correlated with serum BGP and serum calcium. The measurements of biochemical parameters such as serum BGP, ALP and PTH may be useful in the assessment of metabolic bone diseases.

Detection of some retinoid radicals using high-performance liquid chromatography with electron spin resonance spectroscopy or electrochemical detection

Radical species were detected in the incubation mixtures of some retinoids (retinoic acid, retinal, retinol and retinyl acetate) by using the spin-trapping technique. The spin-adducts were resolved by high-performance liquid chromatography on a reversed-phase column with isocratic elution and detected by electron spin resonance spectroscopy and electrochemical detection. The spin-adducts were eluted in the order retinoic acid, retinol, retinyl acetate, in a similar manner to the retinoids themselves. These results suggest that the spin-adducts are products of nitrosobenzene with retinoid radicals in which the retinoid radicals retain their original chemical structures.

Detection of radical species in mixtures of some retinoids with hematin by using the ESR spin-trapping technique

Radical species were detected in mixtures of some retinoids with hematin by using the ESR spin-trapping technique. The rates of radical formation were approximately proportional to the oxygen consumption during the incubation of the retinoids with hematin. HPLC analyses of the incubation mixtures of the retinoids with hematin showed that 5,6-epoxides of the retinoids were formed. The amounts of the epoxides formed were proportional to both oxygen consumption and the amounts of radicals formed. These results suggest that the 5,6-epoxidations proceed via radical intermediates.

Inhibition by chlorogenic acid of haematin-catalysed retinoic acid 5,6-epoxidation

Chlorogenic acid (3-O-caffeoylquinic acid) inhibited haematin- and haemoglobin-catalysed retinoic acid 5,6-epoxidation. Some other phenol compounds (caffeic acid and 4-hydroxy-3-methoxybenzoic acid) also showed inhibitory effects on the haematin- and haemoglobin-catalysed epoxidation, but salicylic acid did not. Of the above compounds, caffeic acid and chlorogenic acid were potent inhibitors compared with the other two, suggesting that the o-hydroquinone moiety of chlorogenic acid and caffeic acid is essential to the inhibition of the epoxidation. Although caffeic acid inhibited retinoic acid 5,6-epoxidation requiring the consumption of O2, formation of retinoic acid radicals was not inhibited on the addition of caffeic acid to the incubation mixture. The above results suggest that caffeic acid does not inhibit the formation of retinoic acid radicals but does inhibit the step of conversion of retinoic acid radical into the 5,6-epoxide.

Detection of radical species in haematin-catalysed retinoic acid 5,6-epoxidation by using h.p.l.c.-e.p.r. spectrometry

E.p.r. signals were detected in an all-trans-retinoic acid/haematin incubation mixture by using an e.p.r. spin-trapping technique. The spin adducts are presumably attributable to some intermediates in haematin-catalysed retinoic acid 5,6-epoxidation, since addition of nitrosobenzene to the reaction mixture dose-dependently inhibited the epoxidation. Analysing the reaction mixture by h.p.l.c.-e.p.r. spectrometry resulted in the detection of three peaks (III-1, III-2, IV) ascribable to the radical species. Two (peaks III-1 and -2) of the three peaks, which appeared 10 min after the reaction had started, seem to be attributable to the radical species directly participating in the epoxidation. The radicals trapped by nitrosobenzene do not appear to be derived from active oxygen, since none of these peaks were detected in a similar h.p.l.c. analysis of O2- and OH.-generating systems. They are presumably derived from retinoic acid. This view is also supported by the following results: none of these peaks were detected in the h.p.l.c. elution profile of the reaction mixture when retinoic acid was absent; peaks III-1 and 2 were detected even under anaerobic conditions, and their peak heights were unchanged under aerobic conditions.