Keiji Nihei

Determination of optimal radiation energy for different breast sizes using ct-simulatior in tangential breast irradiation

BackgroundThe purpose of this study is to determine and recommend the optimal radiation source according to breast size for tangential irradiation in breast conserving therapy.MethodsTwenty-eight patients treated at our department from January 1994 to January 1996 were studied. The dose distribution within the irradiated breast was calculated using ap60Co-gamma ray and 6 MV-X ray. Then we compared 3-D dose distributions of thep60Co-gamma ray and 6 MV-X ray in differentsized breasts. Three parameters (breast volume, chest wall separation, and breast height) were adopted as representative of breast size. We also examined correlations among the three parameters.ResultsWhen the breast size was large (breast volume>400 cmp3, chest wall separation >19.5 cm, or breast height>6.5 cm), the average volume of normal tissue which received more than 110% of the isocenter dose (“hot spot”) was significantly greater with thep60Co-gamma ray than with the 6 MV-X ray (p<0.05). A similar result was obtained with regard to hot spots in the clinical target volume. The cold area that received less than 95% of the isocenter dose was greater using a 6 MV-X ray when the breast size was small (breast volume <200 cmp3, chest wall separation< 17.5 cm, or breast height <5.0 cm). However, the difference was not significant.There was a significant correlation between breast volume and chest wall separation (r=0.849, p< 0.001). Breast volume and breast height were also significantly correlated (r=0.813, p<0.001).ConclusionsSince breast volume and shape are different in each patient, the optimal energy should be selected for each case to obtain uniform dose distribution in breast-conserving therapy. Chest wall separation or breast height, which are measurable without a 3-D planning system, can substitute for breast volume as parameters for breast size. We recommend that thep60Co-gamma ray not be used for treating large breasts, those with chest wall separation>/= 19.5 cm or breast height>/=6.5 cm.

Clinical outcomes and prognostic factors of chemoradiotherapy for postoperative lymph node recurrence of esophageal cancer

Background The therapeutic strategies and prognostic risk factors in patients with lymph node (LN) recurrence of esophageal cancer remain controversial. We assessed clinical outcomes and prognostic factors related to the use of chemoradiotherapy (CRT) for LN recurrence of esophageal squamous cell carcinoma (ESCC) after curative resection. Methods We retrospectively evaluated survival and prognostic factors in 57 patients with LN recurrence of ESCC after curative resection. Patients received CRT using 5-fluorouracil plus cisplatin (FP) or docetaxel. Radiotherapy was delivered at 2 Gy (total dose, 60-66 Gy; median, 60 Gy). Results The median follow-up duration was 24 (range, 3-116) months. The overall survival (OS) rates at 2, 3 and 5 years were 43.7%, 36.9% and 27.6%, respectively. In the univariate analysis of OS, treatment with FP, a single LN recurrence, and a single regional recurrence were associated with a significantly better prognosis (P = 0.04, P = 0.027 and P = 0.0001, respectively). In the multivariate analysis, the combination chemotherapy regimen [hazard ratio (HR), 2.50; 95% confidence interval (CI), 1.23-5.07] and the number of the regional LNs with recurrence (HR, 5.76; 95% CI, 1.22-27.12) were independent prognostic factors. Conclusion Approximately 28% of ESCC patients with LN recurrence after curative resection could achieve long-term survival with CRT. Treatment with FP or patients with a single regional recurrence might improve the treatment outcome.

Comparison of xerostomia incidence after three-dimensional conformal radiation therapy and contralateral superficial lobe parotid-sparing intensity-modulated radiotherapy for oropharyngeal and hypopharyngeal cancer

OBJECTIVE In the treatment of head-neck cancer, parotid-sparing intensity-modulated radiotherapy (IMRT) could reduce the incidence of xerostomia. When the parotid glands cannot be sufficiently spared because of the widespread tumor, contralateral superficial lobe parotid-sparing (CSLPS)-IMRT could be used to reduce marginal recurrence, however the success of this approach remains to be determined. The primary purpose of this study was to compare the incidence of xerostomia between three-dimensional conformal radiotherapy (3D-CRT) and CSLPS-IMRT for oropharyngeal and hypopharyngeal cancer. In a second aim, we also compared the clinical efficacy of 3D-CRT and CSLPS-IMRT. METHODS We retrospectively reviewed the medical records of locally advanced oropharyngeal and hypopharyngeal cancer patients who were treated with definitive concurrent chemoradiotherapy between June 2007 and April 2014. We estimated the average mean dose delivered to the parotid glands, the incidence of xerostomia≥Grade 2, patterns of failure, and survival outcomes. RESULTS Seventeen patients received 3D-CRT and 21 received CSLPS-IMRT. The average mean dose delivered to the superficial lobe of the contralateral parotid gland was 45.3Gy and 26.6Gy (p<0.001), and the incidence of xerostomia≥Grade 2 following treatment was 75% and 26% at 12 months (p=0.012) and 67% and 18% at 24 months (p=0.018) in the 3D-CRT and CSLPS-IMRT groups, respectively. Patterns of failure did not differ between the two groups. The 2-year progression-free survival was 59% and 62% (p=0.73), and the 2-year overall survival rate was 71% and 71% in the 3D-CRT and CSLPS-IMRT groups, respectively (p=0.76). CONCLUSION Incidence of xerostomia was significantly lower in patients receiving CSLPS-IMRT compared with 3D-CRT, while clinical efficacy did not differ between two treatment strategies.

Accelerated Hypofractionated Radiotherapy Versus Stereotactic Body Radiotherapy for the Treatment of Stage I Nonsmall Cell Lung Cancer—A Single Institution Experience With Long-Term Follow-Up

Purpose: Although stereotactic body radiation therapy is one of the standard treatments for stage I nonsmall cell lung cancer, in the case of central tumors it carries the risk of severe adverse events for serial organs. Accelerated hypofractionated radiotherapy is considered a reasonable alternative to treat central tumors. We have been treating central tumors with accelerated hypofractionated radiotherapy using a 75 Gy/25 fr/5 weeks regimen, and we compared the results with those of stereotactic body radiation therapy using 48 Gy/4 fr/1 week. Methods: Patients with central tumors and/or unfit for 1-hour fixation were candidates for accelerated hypofractionated radiotherapy. Based on the proximity to the biologically effective dose at 10 Gy, above accelerated hypofractionated radiotherapy regimen was adopted. Results: From October 2003 to December 2010, 159 patients, who received either accelerated hypofractionated radiotherapy (103 cases) or stereotactic body radiation therapy (56 cases), were included in the analysis. In the accelerated hypofractionated radiotherapy group, 40 (39%) cases were central tumors, whereas all cases were peripheral tumors in the stereotactic body radiation therapy group. Overall 5-year local control and survival rates were 81.9% (95% confidence interval 73.6%-90.1%) and 46.5% (95% confidence interval 36.7%-56.2%), respectively for the accelerated hypofractionated radiotherapy group, and 75.4% (95% confidence interval 63.0%-87.8%) and 44.6% (95% confidence interval 31.6%-57.7%), respectively for the stereotactic body radiation therapy group (n.s.). Among central tumors, ultracentral tumors (21 cases) and the remaining central tumors (19 cases) were similar in both local control and survival. On multivariate analysis, hazard ratios for accelerated hypofractionated radiotherapy versus stereotactic body radiation therapy were <1 for both local control and survival. Pulmonary toxicity was similar in both groups. No serial organ toxicity was observed for central tumors. Conclusions: Accelerated hypofractionated radiotherapy with a 75 Gy/25 fr/5 weeks regimen is promising in that it can obtain similar local control and survival results to stereotactic body radiation therapy, and it can control both central and peripheral tumors without any serial organ toxicities. Based on these results, prospective multicenter trials are worth conducting, especially for ultracentral tumors.

Stereotactic Body Radiotherapy for Spinal Metastases: Clinical Experience in 134 Cases From a Single Japanese Institution

Object: This study aimed to clarify the outcomes of stereotactic body radiotherapy for spinal metastases with a uniform dose fractionation schedule in our institution. Materials and Methods: Patients treated with spine stereotactic body radiotherapy were retrospectively reviewed. The prescribed dose was 24 Gy in 2 fractions. End points were local control, pain control, and adverse events. Local control was defined as elimination, shrinkage, or stable disease in the tumor on imaging evaluations. Pain status was measured on a scale of 0 to 10 by patients’ self-reports, and pain response was defined as the time at which pain scale score decreased by 2 or more from the baseline score without increase in analgesics. In addition, various treatment- and tumor-specific factors were evaluated to determine predictive values for local and pain control. Results: This study included 134 lesions in 131 patients, with: lesion histopathology, lung/colorectal/thyroid/renal/breast/prostate/sarcoma/other cancer, 24/22/18/14/12/10/6/25; reirradiation stereotactic body radiotherapy, 82 (61.2%) cases; and postoperative stereotactic body radiotherapy for epidural spinal cord compression, 45 (33.6%) cases. Median follow-up after stereotactic body radiotherapy was 9 months. The 1-year local control rate was 72.3%. Seventy (79.5%) of the 88 cases with pain from spinal metastases achieved pain response. The 1-year pain progression-free rate was 61.7%. Regarding metastases from colorectal cancer, local and pain control rates at 1 year were significantly lower compared with other cancer types (local control rate, 34.1% vs 81.8%; P < .01; pain progression-free rate, 36.9% vs 69.9%; P = .02). On multivariate analysis, colorectal cancer metastases and radiation history were identified as independent predictors of lower local and pain control rates. Radiation-induced myelopathy, radiculopathy, and vertebral compression fractures were observed in 0, 2 (1.5%), and 16 (11.9%) cases, respectively. Conclusions: This study showed that spine stereotactic body radiotherapy achieved good local and pain control, with a clinically acceptable safety profile. However, stereotactic body radiotherapy may be less effective against spinal metastases from colorectal cancer.

Intensity‑modulated radiotherapy for synchronous cancer of the anal canal and cervix

Due to recent advancements in diagnostic techniques, the incidence of multiple primary cancer has increased; however, synchronous cancer of the anal canal and cervix (SCACC) is rare, and no previous studies have investigated the treatment of this disease. The present study reports a case in which intensity-modulated radiotherapy (IMRT) was used to treat a 64-year-old female with SCACC, inguinal lymphadenopathy and anal pain. The patient was diagnosed with cT3N3M0 stage IIIb anal canal squamous cell carcinoma and cT1b1N0M0 stage Ib1 cervical squamous cell carcinoma, based on biopsy and imaging study data. According to the definitive treatment for advanced-stage anal canal cancer, outpatient treatment with chemoradiotherapy (CRT) using S-1 for SCACC was recommended, as the patient did not want to undergo resection of the anus. Considering the lymph node regions involved in SCACC and the necessary doses, the treatment plan was as follows: Whole pelvis and inguinal lymph node region radiation (36 Gy/20 fractions); a first booster radiation dose (9 Gy/5 fractions) for the whole pelvis; and a second booster radiation dose (14.4 Gy/8 fractions) for the primary lesions. The patient was prescribed S-1 at a dose of 60 mg/m2/day twice daily on days 1–14 and 29–42. The patient experienced grade 2 diarrhea and anal mucositis, but CRT was completed without discontinuation and hospitalization. The patient exhibited a complete response and remained disease-free without any treatment-associated complications at the 6-month follow-up. In conclusion, SCACC was successfully treated with IMRT in the present case. It is important to determine the treatment strategy for synchronous cancer types, taking into consideration the tumor stage, tumor location and patient situation.

Three-Dimensional Non-Coplanar Conformal Radiation Therapy With 75 Gy/25fr/5w Regimen for the Treatment of Stage I NSCLC: A 10-year Experience

Purpose/Objective(s): Stereotactic body radiation therapy (SBRT) has been demonstrated to be an acceptable alternative to surgery for early stage lung cancer in non-surgical candidates. However, there is a concern regarding declining pulmonary function tests (PFT) in some patients after this treatment modality. We undertook a retrospective review of our experience in the treatment of this population. Specifically, we recorded the changes in forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC) and diffusing lung capacity (DLCO) before and after SBRT. These changes were then correlated with possible predictive factors. Materials/Methods: A total of 107 patients with lung malignancies were treated with SBRT between January 2010 and December 2012 at the Juravinski Cancer Center in Hamilton, ON. Age, Charlson-Comorbidity Index, radiation dose, baseline PFTs, smoking history, planning target volume, and post-treatment PFTs were collected. Multivariate regression analysis was done to determine predictive factors in the PFT changes. Results: The median age and follow-up time was found to be 73.7 years and 9.2 months respectively. The median SBRT dose was 48 Gy in 4 fractions. The mean change in FEV1 after SBRT was 0.27 L/sec and in FVC was 0.29 L. Smoking history was the strongest predictive factor in the decline of FEV1 and FVC (p Z 0.008 and p Z 0.047). Furthermore, baseline FEV1 and FVC also correlated with a decrease in the FEV1 and FVC post-SBRT (p Z 0.005 and p Z 0.007 respectively). The PTV volume was also found to cause a statistically significant change in the FVC (p Z 0.02) and trended towards statistical significance in predicting FEV1 changes (p Z 0.07). DLCO was not significantly affected by this treatment modality. Conclusions: SBRT for lung malignancies appear to affect mildly in some patients their PFTs. Predictive factors of these changes are mostly their smoking history and pre-SBRT PFT values. PTV also predicted changes in some subset of the PFTs. Author Disclosure: N. Nguyen: None. T. Tsakiridis: None. H. Zhang: None. S. Anand: None. G. Okawara: None. T. Corbett: None. J. Wright: None.