Michihide Mitsumori

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.

Bronchial artery embolization for hemoptysis: Immediate and long-term results

The purpose of this study was to evaluate the immediate and long-term results in 63 patients who underwent transarterial embolization for control of hemoptysis. Overall immediate success rate was 86.1%. At long-term follow-up 50% of patients showed complete remission, 22% partial remission, and 28% recurrent hemoptysis. Hemoptysis remained controlled for a mean of 22 months and a median of 14 months. The long-term results among four disease groups differed substantially. Patients with bronchiectasis showed the best results, followed by those with idiopathic disease and with inflammation; patients with neoplasm showed the worst results.

Radiation therapy for T1,2 glottic carcinoma: impact of overall treatment time on local control

PURPOSE Local control probabilities of T1,2 glottic laryngeal cancer were evaluated in relation to dose and fractionation of radiation therapy (RT). MATERIALS AND METHODS Between 1975 and 1993, 96 T1N0M0 glottic cancers and 32 T2N0M0 glottic cancers were treated with definitive RT. Total RT dose was 60-66 Gy/2 Gy for most of the T1 and T2 tumors, although 10 T2 tumors were treated with hyperfractionation (72-74.4 Gy/1.2 Gy bid). Of the 128 patients, 90 T1 glottic tumors and 30 T2 glottic tumors were followed for > 2 years after treatment. Multivariate analyses using the Cox proportional hazards model and a logistic regression analysis were performed to evaluate the significance of prognostic variables on local control. RESULTS The 5-year local control probability for T1 tumors was 85%, whereas that for T2 tumors was 71%. Multivariate analyses demonstrated that only overall treatment time (OTT) was a significant variable for local control. Total RT dose, normalized total doses at a fraction size of 2 Gy, and fraction size were not significant. Local control probability of T1 tumors with an OTT of 42-49 days was significantly higher than that of tumors with an OTT of > 49 days (P < 0.02). Only a 1-week interruption of RT, due to holidays, significantly reduced the 5-year local control probability of T1 glottic tumors from 89 to 74% (P < 0.05). CONCLUSIONS These results indicate that OTT is a significant prognostic factor for local control of T1 glottic tumors.

Current status of stereotactic body radiotherapy for lung cancer

Stereotactic radiotherapy (SRT) for extracranial tumors has been recently performed to treat lung and liver cancers, and has subsequently been named stereotactic body radiotherapy (SBRT). The advantages of hypofractionated radiotherapy for treating lung tumors are a shortened treatment course that requires fewer trips to the clinic than a conventional program, and the adoption of a smaller irradiated volume allowed by greater setup precision. This treatment is possible because the lung and liver are considered parallel organs at risk. The preliminary clinical results, mostly reported on lung cancer, have been very promising, including a local control rate of more than 90%, and a relatively low complication rate. The final results of a few clinical trials are awaited. SBRT may be useful for the treatment of stage I lung tumors.

Increased heating efficiency of hyperthermia using an ultrasound contrast agent: A phantom study

It is known that there are large temperature elevations in proximity to air bubbles during US (ultrasound) heating. The existence of tiny air bubbles in the target tissue may enhance the temperature elevation in US hyperthermia. To examine this hypothesis, phantom tissue experiments using an US contrast agent consisting of tiny air bubbles surrounded by a 5% (w/v) human albumin shell (Alb) were performed. As a phantom tissue, a 2 cm cube of beef was used. The phantom tissue was heated with or without the US contrast agent by an US hyperthermia device for 3 min. The heating device was operated at 1.5 MHz with the US intensity of 0.9 W/cm2. Physiological saline solution, iodized oil, and ethanol were used for control experiments. The effect of multiple needle punctures to the beef phantom was also examined. The temperature elevation rate (TER) was defined as the ratio of temperature elevation by heating with Alb or control materials to the temperature elevation by US heating alone. The TER of Alb was 1.7, whereas the TERs of the control materials and of the multiple needle punctures were approximately 1. The administration of Alb significantly increased the temperature in US hyperthermia. In addition, the heating efficiency of Alb was compared to the effect of an increase in the US intensity. Phantom tissue was heated at various US intensities. When the US intensity was increased from 0.9 to 1.8 W/cm2, the temperature elevated by approximately 1.7-fold. Thus, the effect of the administration of Alb was almost equivalent to the effect of increase in US power intensities from 0.9 to 1.8 W/cm2 in the present experimental settings. The results suggest that the US contrast agent can be a potential enhancer in US hyperthermia.

Patterns of Radiotherapy Practice for Patients With Cervical Cancer (1999–2001): Patterns of Care Study in Japan

PURPOSE To describe the patterns of definitive radiotherapy practice for patients with uterine cervical cancer from 1999 to 2001 in Japan. METHODS AND MATERIALS The Japanese Patterns of Care Study (JPCS) working group conducted a third extramural audit survey of 68 institutions and collected specific information on 324 cervical cancer patients treated with definitive radiotherapy. RESULTS Almost all patients (96%) were treated with whole pelvic radiotherapy using opposing anteroposterior fields (87%). A midline block was used in 70% of the patients. Intracavitary brachytherapy (ICBT) was applied in 82% of cases. Most patients (89%) were treated with high-dose rate (HDR) ICBT. Calculation of doses to organs at risk (ICRU 38) was performed for rectum in 25% of cases and for bladder in 18% of cases. Only 3% of patients were given intravenous conscious sedation during ICBT applicator insertions. The median total biologically effective dose at point A (EBRT+ICBT) was 74 Gy(10) in cases treated with HDR-ICBT. There was no significant difference in total biologically effective dose between stages. The median overall treatment time was 47 days. Concurrent chemoradiation was applied in 17% of patients. CONCLUSIONS This study describes the general patterns of radiotherapy practice for uterine cervical cancer in Japan. Although methods of external radiotherapy seemed to be appropriate, there was room for improvement in ICBT practice, such as pretreatment. A substantial difference in total radiotherapy dose between Japan and the United States was observed.

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 case of allergic reaction to surgical metal clips inserted for postoperative boost irradiation in a patient undergoing Breast-conserving therapy

We report a case of a 28-year-old woman with right-sided breast cancer. The patient had been treated for atopic dermatitis since her infancy. She underwent breast-conserving surgery (BCS) in July 1998, and three titanium clips were placed at the margin of the excision cavity at the time of surgery. Two months after surgery, the patient exhibited a rapid exacerbation of atopic dermatitis. Various drugs were suspected to be the cause of the allergic reaction, but the results of a bi-digital O-ring test (BDORT) suggested an allergic reaction to titanium clips. In August 1999, the patient underwent a second operation to remove the titanium clips under local anesthesia. Allergy to surgical titanium clips is a rare complication, but in patients with a history of severe allergic diseases, a preoperative immunologic examination should be performed and the patient’s history of metal allergy should be investigated.

Japanese Structure Survey of Radiation Oncology in 2005 Based on Institutional Stratification of Patterns of Care Study

PURPOSE To evaluate the structure of radiation oncology in Japan in terms of equipment, personnel, patient load, and geographic distribution to identify and improve any deficiencies. METHODS AND MATERIALS A questionnaire-based national structure survey was conducted between March 2006 and February 2007 by the Japanese Society of Therapeutic Radiology and Oncology. These data were analyzed in terms of the institutional stratification of the Patterns of Care Study. RESULTS The total numbers of new cancer patients and total cancer patients (new and repeat) treated with radiotherapy in 2005 were estimated at approximately 162,000 and 198,000, respectively. In actual use were 765 linear accelerators, 11 telecobalt machines, 48 GammaKnife machines, 64 60Co remote-controlled after-loading systems, and 119 192Ir remote-controlled after-loading systems. The linear accelerator systems used dual-energy function in 498 systems (65%), three-dimensional conformal radiotherapy in 462 (60%), and intensity-modulated radiotherapy in 170 (22%). There were 426 Japanese Society of Therapeutic Radiology and Oncology-certified radiation oncologists, 774 full-time equivalent radiation oncologists, 117 medical physicists, and 1,635 radiation therapists. Geographically, a significant variation was found in the use of radiotherapy, from 0.9 to 2.1 patients/1,000 population. The annual patient load/FTE radiation oncologist was 247, exceeding the Blue Book guidelines level. Patterns of Care Study stratification can clearly discriminate the maturity of structures according to their academic nature and caseload. CONCLUSIONS The Japanese structure has clearly improved during the past 15 years in terms of equipment and its use, although the shortage of manpower and variations in maturity disclosed by this Patterns of Care Study stratification remain problematic. These constitute the targets for nationwide improvement in quality assurance and quality control.

Cosmetic Results and Complications after Breast Conserving Therapy for Early Breast Cancer

BackgroundThe cosmetic and functional results of breast conserving therapy for early breast cancer were evaluated. These are important endpoints in the assessment of breast conserving therapy in addition to tumor control and survival. The factors suspected to influence cosmesis were also analyzed.MethodsIn 206 patients with stage I and II breast cancer treated by wide excision and axillary dissection followed by radiation therapy, the cosmetic results and complications were analyzed. The cosmetic outcome was assessed by a scoring method and breast retraction assessment (BRA). As complications, arm edema and restriction of shoulder movement and late skin reactions were analyzed.ResultsOf the 206 patients 92% showed an excellent to good cosmetic score before radiation therapy. The score deteriorated, but gradually improved and stabilized after 1 year. Eighty-one percent of the patients had an excellent to good cosmetic score at 3 years. The BRA of the 206 patients was 1.8 cm on average before radiation therapy. It increased to 2.3 cm after termination of radiation therapy, and did not change thereafter. Tumor size over 2 cm (p=0.005) and tumors in the inner quadrant (p=0.003) were factors which negatively affected the cosmetic score at 3 years. Tumor size over 2 cm (p=0.003), tumors in the upper quadrant (p=0.005), or a nipple-tumor distance of more than 2 cm (p=0.01) were also negative factors for the BRA at 3 years. Arm edema, restriction of shoulder movement, and late skin reaction were generally mild, and were observed in 12%, 0% and 34% of patients at 3 years, respectively.ConclusionsThe overall cosmetic results of breast conserving therapy are acceptable and the complication rate is low. Tumor characteristics, tumor size, location and nipple-tumor distance are factors that affect cosmesis.