Masakazu Ogura

Local hyperthermia combined with external irradiation for regional recurrent breast carcinoma

BackgroundsThe purpose of this study was to evaluate the therapeutic effects of hyperthermia in combination with radiotherapy for locoregional recurrence of breast cancer, and to assess the factors related to subsequent local tumor control.MethodsBetween March 1981 and February 2001, 85 lesions in 73 patients were treated with local hyperthermia combined with external irradiation. Of 75 evaluable lesions, 41 were previously irradiated. Mean radiation dose to the previously unirradiated area was 59.5 ± 6.8 Gy (range, 40–70 Gy), while a total dose of 43.0 ± 12.4 Gy (range, 12–74.4 Gy) was administered to previously irradiated tumors. Hyperthermia was administered once or twice per week. The average number of hyperthermia sessions was 4.5 (2–9).ResultsComplete responses (CRs) were achieved in 56% (23/41) of previously irradiated and 47% (16/34) of unirradiated tumors. There was no significant difference in the CR rate between the two groups. Compared with the response of bulky/nodular tumors, diffuse/multiple small nodular tumors showed a higher CR rate at 4 weeks after treatment. However, at 6 months after treatment, they showed a significantly lower local control rate.ConclusionsThe present findings suggested a significant benefit of local hyperthermia combined with radiotherapy in the treatment of locally recurrent breast cancer, especially for previously irradiated recurrence, by reducing the total irradiation dose. Diffuse/multiple small nodular tumors respond earlier than bulky/large nodular tumors; however, they tend to recur within the treatment field.

A tumor-specific gene therapy strategy targeting dysregulation of the VHL/HIF pathway in renal cell carcinomas

Hypoxia‐inducible factors, key transcription factors for hypoxia‐dependent gene expression, play important roles in angiogenesis and tumor growth. The VHL protein binds to the α subunit of (HIF‐α) for its oxygen‐dependent degradation. VHL mutations are found frequently in sporadic RCC. Disruption of VHL results in an abnormal accumulation of HIF‐α, leading to the upregulation of downstream genes such as the vascular endothelial growth factor gene. We constructed a luciferase reporter vector driven by hypoxia‐responsive elements (5HRE/luc) and a therapeutic vector expressing a herpes simplex virus thymidine kinase gene (5HRE/tk). In the transient transfection assay using VHL‐deficient 786‐O cells, constitutive luciferase expression was detected under both aerobic and hypoxic conditions. In contrast, 786‐O cells transfected with a wild‐type VHL showed hypoxia‐inducible luciferase activity. In in vitro MTS assay, 50% of growth inhibition of 786‐O cells stably transfected with 5HRE/tk was achieved with exposure to 0.2 µg/mL of GCV under both aerobic and hypoxic conditions. Xenografts of the stable clone in SCID mice exhibited a marked regression on daily injections of GCV (50 mg/kg) for 10 days. In conclusion, a hypoxia‐responsive vector may have therapeutic potential for RCC with VHL mutations. (Cancer Sci 2005; 96: 288 –294)

Radiation Therapy for Brain Metastases from Breast Cancer

BackgroundBreast cancer is one of the most common malignancies that metastasize to the brain. Radiation therapy plays a central role in the management of brain metastases.MethodsThe medical records of 36 patients with brain metastases from breast cancer who underwent whole-brain radiation therapy (WBRT) at Kyoto University Hospital between 1993 and 2001 were reviewed. The treatment outcomes were analyzed retrospectively.ResultsThe median age at the time of diagnosis of brain metastases was 52 years. Only 4 patients (11%) had a single metastasis, while the others had multiple metastases. Uncontrolled extracranial metastases were present in 26 patients at the time of diagnosis of brain metastases. All patients received WBRT at a median dose of 31 Gy. Eight patients received conventional external-beam boost irradiation, and 2 received boost stereotactic radiosurgery (SRS). The overall median survival time was 7.9 months. Uncontrolled extracranial metastases except for bone metastases and old age were significantly associated with a poor survival rate. Twenty-six patients (82%) showed initial response, but 15 developed CNS failure, including 9 patients whose tumor recurred at the original site, 4 patients who developed tumors elsewhere in the brain and 3 patients who exhibited meningeal spread. The median duration of intracranial failure was 5.0 months. Whole-brain dose, and total tumor dose did not affect intracranial control.ConclusionsRadiation therapy yielded a high initial response, but the duration of effect was limited with external beam irradiation alone. New treatment strategies such as adding SRS need to be studied further.

Assessment of interfractional prostate motion in patients immobilized in the prone position using a thermoplastic shell.

The aim of this study was to evaluate the interfractional prostate motion of patients immobilized in the prone position using a thermoplastic shell. A total of 24 patients with prostate calcifications detectable using a kilo-voltage X-ray image-guidance system (ExacTrac X-ray system) were examined. Daily displacements of the calcification within the prostate relative to pelvic bony structures were calculated by the ExacTrac X-ray system. The average displacement and standard deviation (SD) in each of the left–right (LR), anterior–posterior (AP), and superior–inferior (SI) directions were calculated for each patient. Based on the results of interfractional prostate motion, we also calculated planning target volume (PTV) margins using the van Herk formula and examined the validity of the PTV margin of our institute (a 9-mm margin everywhere except posteriorly, where a 6-mm margin was applied). In total, 899 data measurements from 24 patients were obtained. The average prostate displacements ± SD relative to bony structures were 2.8 ± 3.3, −2.0 ± 2.0 and 0.2 ± 0.4 mm, in the SI, AP and LR directions, respectively. The required PTV margins were 9.7, 6.1 and 1.4 mm in the SI, AP and LR directions, respectively. The clinical target volumes of 21 patients (87.5%) were located within the PTV for 90% or more of all treatment sessions. Interfractional prostate motion in the prone position with a thermoplastic shell was equivalent to that reported for the supine position. The PTV margin of our institute is considered appropriate for alignment, based on bony structures.

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.

Improvement of registration accuracy in accelerated partial breast irradiation using the point-based rigid-body registration algorithm for patients with implanted fiducial markers

PURPOSE To investigate image-registration errors when using fiducial markers with a manual method and the point-based rigid-body registration (PRBR) algorithm in accelerated partial breast irradiation (APBI) patients, with accompanying fiducial deviations. METHODS Twenty-two consecutive patients were enrolled in a prospective trial examining 10-fraction APBI. Titanium clips were implanted intraoperatively around the seroma in all patients. For image-registration, the positions of the clips in daily kV x-ray images were matched to those in the planning digitally reconstructed radiographs. Fiducial and gravity registration errors (FREs and GREs, respectively), representing resulting misalignments of the edge and center of the target, respectively, were compared between the manual and algorithm-based methods. RESULTS In total, 218 fractions were evaluated. Although the mean FRE/GRE values for the manual and algorithm-based methods were within 3 mm (2.3/1.7 and 1.3/0.4 mm, respectively), the percentages of fractions where FRE/GRE exceeded 3 mm using the manual and algorithm-based methods were 18.8%/7.3% and 0%/0%, respectively. Manual registration resulted in 18.6% of patients with fractions of FRE/GRE exceeding 5 mm. The patients with larger clip deviation had significantly more fractions showing large FRE/GRE using manual registration. CONCLUSIONS For image-registration using fiducial markers in APBI, the manual registration results in more fractions with considerable registration error due to loss of fiducial objectivity resulting from their deviation. The authors recommend the PRBR algorithm as a safe and effective strategy for accurate, image-guided registration and PTV margin reduction.

Agreement between patients' and radiation oncologists' cancer diagnosis and prognosis perceptions: A cross sectional study in Japan.

This study assessed agreement between radiation oncologist- and cancer patient-reported perceptions about cancer diagnosis, time since diagnosis, treatment purpose, and whether life expectancy had been discussed; and described preferences for prognosis discussions. Adult cancer patients receiving radiotherapy at a Japanese hospital were invited to complete a touchscreen tablet survey. Patient survey responses were linked and comparisons made with a survey completed by their radiation oncologist. Among 146 cancer patient-oncologist dyads, there was almost perfect agreement on cancer diagnosis (ĸ = 0.88, 95% CI: 0.82–0.94), substantial agreement on time since diagnosis (ĸ = 0.70, 95% CI: 0.57–0.83) and moderate agreement on whether treatment goal was curative or palliative (ĸ = 0.44, 95% CI: 0.28–0.57; all p’s < 0.0001). Agreement about whether a life expectancy discussion had occurred was less than expected by chance (κ = -0.06, p = 0.9). Radiation oncologists reported that they had spoken to over two thirds of patients about this, whilst less than one third of patients stated that this discussion had occurred with their radiation oncologist. Over half of the patients who had not discussed life expectancy wanted to. Patients had variable preferences for whether they (80%), their radiation oncologist (78%) or their partner/family (52%) should decide whether they discuss their life expectancy. Although patient self-reported information about diagnosis and time since diagnosis appears to be reasonably accurate (compared with clinician-reported information), limitations of self-reported data about prognostic discussions were highlighted by poor agreement between patient- and clinician-reported information about whether prognostic discussions have occurred. Additional support is needed to improve prognosis communication and understanding in radiation oncology settings.

Regional recurrence in breast cancer patients with one to three positive axillary lymph nodes treated with breast-conserving surgery and whole breast irradiation

Radiotherapy with breast-conserving therapy plays a crucial role in the treatment of early breast cancer. However, optimal radiotherapy targets have been controversial. We therefore evaluated regional recurrence in breast cancer patients with one to three positive lymph nodes (LNs) treated with breast-conserving surgery (BCS) followed by whole-breast irradiation (WBI). From 1993 to 2010, 121 breast cancer patients with one to three positive LNs who underwent BCS followed by WBI were analyzed. All patients underwent radiotherapy with two tangential fields to the whole breast. To evaluate the radiation dose to the axillary LNs, we contoured axillary LNs area and evaluated the dose–volumetric parameters. The median follow-up time was 112.4 months (range, 15.6–248.1 months). The 5-year overall survival and disease-free survival rates were 95.6% and 86.6%, respectively. The 5-year regional recurrence–free rate (RRFR) was 97.4%. During follow-up, six patients had regional recurrence. The pathological T stage was the factor best associated with the 5-year RRFR using the log-rank test, with 100.0% in the pT1 cohort versus 94.7% in the pT2–4 cohort (P < 0.01). The radiation dose to the axillary LNs did not contribute to the RRFR. In conclusion, while the pathological T stage was the prognostic factor best associated with regional recurrence, few regional recurrences were observed in early breast cancer patients with one to three LNs treated with BCS followed by WBI. Unintentional radiation doses to the axillary LNs using standard WBI were not related to the RRFR after axillary dissection.