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ABSTRACT: The authors developed a Telecommunication-HElped Radiotherapy Planning and Information SysTem (THERAPIST), then estimated its clinical benefit in radiotherapy in district hospitals where consultation with the university hospital was required. The system consists of a personal computer with an image scanner and a digital camera, set up in district hospitals and directly connected via ISDN to an image server, and a treatment planning device set up in a university hospital. Image data and consultative reports are sent to the server. Radiation oncologists at the university hospital determine a treatment schedule and verify actual treatment fields. From 1998 to 1999, 12 patients with malignant spinal cord compression (MSCC) were treated by emergency radiotherapy with the help of this system. Image quality, transmission time, and cost benefit also were satisfactory for clinical use. The mean time between the onset of symptoms and the start of radiotherapy was reduced significantly from 7.1 days to 0.8 days (P < .05) by the introduction of the system. Five of 6 nonambulant patients became ambulant after the introduction of THERAPIST compared with 2 of 8 before the introduction of THERAPIST. The treatment outcome was significantly better after the introduction of the system (P < .05), and suggested to be beyond the international standard. The telecommunication-helped radiotherapy and information system was useful in emergency radiotherapy in district hospitals for patients with MSCC for whom consultation with experienced radiation oncologists at a university hospital was required.
Journal of Digital Imaging 09/2001; 14(3):124-30. · 1.25 Impact Factor
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ABSTRACT: To use digitally reconstructed radiography (DRR) and digitally compressed portal images in distant consultation using a telecommunications network, the verification performance of DRR and digitally compressed portal images on the image console was investigated.
A human thoracic phantom was scanned with computed tomography (CT). Radiotherapy was planned at 5 different anatomic locations. A digitally reconstructed radiograph was made; verification films of the phantom were then taken with 6-MV X-rays. The treatment center was intentionally dislocated. Fifty sets of DRR and portal images were seen by 7 doctors on a conventional view-box (view-box method) to judge whether the treatment center was dislocated. These image sets were digitalized by a film scanner, compressed to 1/10 Joint Photographic Experts Group (JPEG) format, and compared on an image console by the same physicians (image-console method). The verification performance of the image console method was compared with that of the view-box method by means of receiver operating characteristic (ROC) analysis. Clinically, 159 portal-image-sets were verified with the image-console method and the appropriateness of the decision was later assessed by the view-box method.
The accuracy of the treatment verification was estimated to be 88.8% by the conventional view-box method and 88.3% by the image-console method. There was no statistically significant difference in the verification performances of the conventional method (Az = 0.86+/-0.02) and the image console method (Az = 0.84+/-0.07). Frequent digital image-processing modification was positively related to the accuracy of verification. Clinically, there were 3 (1.8%) major corrections, 31 (19.5%) minor corrections, and 123 cases with no correction. No further correction was called for by the re-evaluation using the view-box method.
The verification performance of DRR and digitally compressed portal images on the image console was as accurate as the conventional method. Distant consultation using DRR and portal images through telecommunication is usable in clinical practice.
International Journal of Radiation OncologyBiologyPhysics 07/2001; 50(2):579-85. · 4.11 Impact Factor
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ABSTRACT: We developed an MRI system for three-dimensional planning in radiotherapy. Its contribution on gross tumor volume (GTV) delineation of central nervous system (CNS) diseases was evaluated.
The MRI system, with corrected distortion, was registered on computed tomography (CT) by means of fiducial/anatomic landmarks. In 41 consecutive patients with various CNS diseases, GTVs determined by MRI/CT registration (MR/CT-GTV) and CT alone (CT-GTV) were compared. Hard copies of diagnostic MRI were shown to doctors when CT-GTV was determined to simulate a conventional planning situation. Multi-observer volumetric analysis was conducted, assessing interobserver deviations among four radiation oncologists and intermethodological deviations between MR/CT-GTV and CT-GTV.
Overall, the mean of geometric distortion was significantly reduced from 1.08 mm to 0.3 mm by distortion correction (p < 0.0001). The contribution of the correction was apparent at >12.0 cm radius from the center of the magnetic field. Interobserver deviation was significantly reduced by MR/CT registration (p = 0.005). The improvement was significant for acoustic neurinoma (p = 0.038), astrocytomas (p = 0.043), and lesions at the cerebellum/brainstem (p = 0.008). The regression coefficient between MR/CT-GTV and CT-GTV was <0.9 for cerebellum/brainstem lesions, suggesting that MRI/CT-GTV was smaller than CT-GTV.
This system is feasible for three-dimensional planning and was shown to reduce interobserver deviations in GTV delineation for CNS diseases.
International Journal of Radiation OncologyBiologyPhysics 07/2001; 50(3):821-7. · 4.11 Impact Factor
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ABSTRACT: The prognostic value of tumor apoptosis was studied in patients with oropharyngeal squamous cell carcinoma treated with radical radiotherapy. Forty-eight patients with oropharyngeal squamous cell carcinoma who received radical radiotherapy between 1990 and 1995 were enrolled in the study. The radiation treatment for all patients involved the administration of 65 Gy in 26 fractions over a 6.5-week period. The apoptotic index (AI; the apoptotic cell count per 1000 tumor cells ) was distributed from 0 to 10 with a median at 2 and a mode of 1. There was a significant linear correlation between the AI and mitotic index (MI) (r=0.393, 95% confidence interval: 0.129-0.605). The cause-specific 5-year survival for patients with AI greater than the median was 46% and for the counterpart was 41%. There was no difference in cause-specific survival between AI/MI greater than the median (50%) and AI/MI smaller than the median (36%). The number of patients was too small to draw definite conclusions, but the AI and the AI/MI before treatment were not shown to have a prognostic value for oropharyngeal squamous cell carcinoma in our study. The primary sites and treatment methods may influence the prognostic value of AI even for the same histological types.
Oral Oncology 03/2001; 37(2):159-63. · 2.86 Impact Factor
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H Shirato,
S Shimizu,
T Kunieda,
K Kitamura,
M van Herk,
K Kagei,
T Nishioka, S Hashimoto,
K Fujita,
H Aoyama,
K Tsuchiya,
K Kudo,
K Miyasaka
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ABSTRACT: To reduce uncertainty due to setup error and organ motion during radiotherapy of tumors in or near the lung, by means of real-time tumor tracking and gating of a linear accelerator.
The real-time tumor-tracking system consists of four sets of diagnostic X-ray television systems (two of which offer an unobstructed view of the patient at any time), an image processor unit, a gating control unit, and an image display unit. The system recognizes the position of a 2.0-mm gold marker in the human body 30 times per second using two X-ray television systems. The marker is inserted in or near the tumor using image guided implantation. The linear accelerator is gated to irradiate the tumor only when the marker is within a given tolerance from its planned coordinates relative to the isocenter. The accuracy of the system and the additional dose due to the diagnostic X-ray were examined in a phantom, and the geometric performance of the system was evaluated in 4 patients.
The phantom experiment demonstrated that the geometric accuracy of the tumor-tracking system is better than 1.5 mm for moving targets up to a speed of 40 mm/s. The dose due to the diagnostic X-ray monitoring ranged from 0.01% to 1% of the target dose for a 2.0-Gy irradiation of a chest phantom. In 4 patients with lung cancer, the range of the coordinates of the tumor marker during irradiation was 2.5-5.3 mm, which would have been 9.6-38.4 mm without tracking.
We successfully implemented and applied a tumor-tracking and gating system. The system significantly improves the accuracy of irradiation of targets in motion at the expense of an acceptable amount of diagnostic X-ray exposure.
International Journal of Radiation OncologyBiologyPhysics 12/2000; 48(4):1187-95. · 4.11 Impact Factor
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ABSTRACT: High-speed magnetic resonance imaging (MRI) was applied to the determination of the planning target volume (PTV) of moving hepatobiliary tumors.
Three moving tumors, including two metastatic hepatic tumors and one bile duct tumor, were examined using high-speed MRI and reference fiducial markers before external radiotherapy. Patients were examined for 30 seconds under conditions of normal breathing during the examination. The coordinates of the center of the tumor contours were shown on sagittal and coronal images displayed on the monitor.
The maximum length of movement was 10.6 +/- 7.0 mm in a craniocaudal direction; 5.2 +/- 1.8 mm in a lateral direction; and 4.6 +/- 1.6 mm in a ventrodorsal direction. When the PTV was determined using MRI at exhalation phase with a 10-mm safety margin, clinical target volume (CTV) was not covered in 19% of all images in the 3 patients. With MRI at inhalation phase with a 10-mm safety margin, CTV was not covered in 36% of all images.
Four-dimensional treatment planning using high speed MRI, and integrating time and spatial information, has the potential to determine the planning target volume of moving body tumors more precisely than does conventional CT planning.
International Journal of Radiation OncologyBiologyPhysics 10/2000; 48(2):471-4. · 4.11 Impact Factor
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ABSTRACT: To minimize side effects and to achieve a high local control rate, three-dimensional (3D) small-volume irradiation was used for locally residual or recurrent nasopharyngeal carcinoma.
Between July 1992 and March 1998, 18 tumors (12 residual and 6 local recurrent cases) were treated with 3D planned small-volume irradiation. The total dose (i.e., the dose of conventional radiotherapy plus that of the 3D irradiation) was 78.4 Gy (74.8-91.0 Gy) in its mean value for residual disease and 105.0 Gy (94.8-125 Gy) for recurrence. The mean value of the 90% isodose volume was 40.3 cc (8.0-94.0 cc). The mean follow-up period from the start of the boost or re-irradiation was 39 months.
The 3-year local control rate of the 12 residual tumors was 70%. Of 9 T4 residual tumors, 7 were controlled at a follow-up period between 17 and 70 months (median of 42 months). Of 6 recurrent tumors treated with re-irradiation, 3 were controlled at a follow-up period between 7 and 28 months. In the case of booster therapy, trismus occurred in 1 patient with a total dose of 91 Gy. Among the patients receiving re-irradiation, a temporary ulceration of the nasopharyngeal mucosa developed in 1 patient with a total dose of 111 Gy.
3D small-volume irradiation was effective and safe in treating residual or recurrent nasopharyngeal carcinoma.
International Journal of Radiation OncologyBiologyPhysics 10/2000; 48(2):495-500. · 4.11 Impact Factor
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H Shirato,
S Shimizu,
K Kitamura,
T Nishioka,
K Kagei, S Hashimoto,
H Aoyama,
T Kunieda,
N Shinohara,
H Dosaka-Akita,
K Miyasaka
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ABSTRACT: To achieve precise three-dimensional (3D) conformal radiotherapy for mobile tumors, a new radiotherapy system and its treatment planning system were developed and used for clinical practice.
We developed a linear accelerator synchronized with a fluoroscopic real-time tumor tracking system by which 3D coordinates of a 2.0-mm gold marker in the tumor can be determined every 0.03 second. The 3D relationships between the marker and the tumor at different respiratory phases are evaluated using CT image at each respiratory phase, whereby the optimum phase can be selected to synchronize with irradiation (4D treatment planning). The linac is triggered to irradiate the tumor only when the marker is located within the region of the planned coordinates relative to the isocenter.
The coordinates of the marker were detected with an accuracy of +/- 1 mm during radiotherapy in the phantom experiment. The time delay between recognition of the marker position and the start or stop of megavoltage X-ray irradiation was 0.03 second. Fourteen patients with various tumors were treated by conformal radiotherapy with a "tight" planning target volume (PTV) margin. They were surviving without relapse or complications with a median follow-up of 6 months.
Fluoroscopic real-time tumor tracking radiotherapy following 4D treatment planning was developed and shown to be feasible to improve the accuracy of the radiotherapy for mobile tumors.
International Journal of Radiation OncologyBiologyPhysics 10/2000; 48(2):435-42. · 4.11 Impact Factor
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ABSTRACT: Our intent was to investigate the role of radiotherapy in treating external auditory canal squamous cell carcinoma, especially in early stages of disease.
The treatment results for 20 patients treated between 1980 and 1998 were retrospectively analyzed. Radiotherapy was used as an initial treatment without surgery in eight patients and with surgery in 12 patients. The patients treated by radiotherapy alone received 65 Gy in 26 fractions over 6.5 weeks. The patients treated with radiotherapy perioperatively received 30-75 Gy in 12-30 fractions. The follow-up period for survivors including patients died of intercurrent disease ranged from 7 to 205 months (mean: 71 months).
The 5-year survival rate calculated by the Kaplan-Meier method for all patients was 59%. According to Stell classification (Laryncol. Otol. 99 (1985) 847), the 5-year survival rates for eight patients with T1 disease and eight with T2 disease were 100 and 38%, respectively. In the eight patients with T1 disease, disease control was 100%. Local control with hearing preservation was achieved in five patients with T1 disease by radiotherapy alone. No late complications related to radiotherapy were observed.
A precise diagnosis of the disease in terms of whether or not it has invaded the bone is important in order to predict the treatment outcome. Radiotherapy with or without surgery is the treatment of choice for patients with T1-stage disease. Surgery with radiotherapy is recommended as standard care for tumors with bony invasion.
Radiotherapy and Oncology 09/2000; 56(2):221-5. · 5.58 Impact Factor
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ABSTRACT: To evaluate the value of skull-base abnormality on MRI for predicting local recurrence in nasopharyngeal carcinoma.
Between November 1988 and February 1997, 48 patients with NPC were examined with both MRI (1.5 T) and CT prior to radiation therapy. T classification (1987 UICC) based on physical examination and CT findings were T1 in 3 cases, T2 in 22, T3 in 9, and T4 in 14. On MRI, low-intensity tissue with Gd enhancement in the marrow of the skull was considered to be a suspicious finding of skull-base invasion. CT simulation was performed in all patients. The total dose to the primary tumor was 60-75 Gy (mean, 67 Gy). The mean follow-up period was 42 months.
All 14 T4 patients had abnormal tissue in the marrow of the skull base on MRI. Thirty-eight percent (13 of 34) of T1-3 patients were suspected to have skull-base invasion based on MRI (0% for T1, 27% [6 of 22] for T2, and 78% [7 of 9] for T3). The 5-year local control rate was significantly different between T1-3 and T4 tumors (97% vs. 69%, p < 0.025) but was not different by the presence of the MRI abnormality in the skull base.
Skull-base invasion suspected solely by MRI does not relate to local recurrence provided that careful treatment planning is performed with the aid of MRI and CT simulator.
International Journal of Radiation OncologyBiologyPhysics 06/2000; 47(2):395-400. · 4.11 Impact Factor
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ABSTRACT: Tumor control and late complication rates of irregularly shaped four-field whole pelvic radiotherapy using CT simulation were compared with those of whole pelvic radiotherapy using parallel-opposed fields in a non-randomized study.
From 1986 to 1996, 74 patients who underwent surgery for clinical stage I, II or III squamous or adenosquamous cell carcinoma of the uterine cervix were treated with postoperative radiotherapy consisting of 50 Gy in 25 fractions in 6 weeks. Thirty-four patients were treated with an irregularly shaped four-field technique following computed tomography (CT) simulation using beam's eye view and three-dimensional treatment planning and lead blocks. Forty patients received the conventional two-field technique, with CT simulation in 13 patients and X-ray simulation in 27 patients. There was no significant difference in patients' characteristics between the two groups.
There was no statistical difference in survival, relapse-free survival or pelvic control rate between the two-field and irregularly shaped four-field groups with a mean follow-up period of 60 months. The actual 5-year pelvic control rate was 94% for the two-field technique and 100% for the irregularly shaped four-field technique. The incidence of grade II-III bowel complications in the irregularly shaped technique group (2.9%, 1/34) was significantly lower than that in the two-field technique group (17.5%, 7/40) (p < 0.05). The actual 5-year complication rates of grade II leg edema were 28.6 and 3.1% for the two-field technique and irregularly shaped four-field technique groups, respectively (p = 0.0123).
Irregularly shaped four-field post-operative pelvic radiotherapy using CT simulation appears to be as effective as parallel-opposed whole pelvic radiotherapy with a lower incidence of bowel complication and chronic leg edema.
Japanese Journal of Clinical Oncology 04/2000; 30(4):180-4. · 1.78 Impact Factor
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ABSTRACT: Three-dimensional (3D) treatment planning has often been performed while patients breathe freely, under the assumption that the computed tomography (CT) images represent the average position of the tumor. We investigated the impact of respiratory movement on the free-breathing CT images of small lung tumors using sequential CT scanning at the same table position.
Using a preparatory free-breathing CT scan, the patient's couch was fixed at the position where each tumor showed its maximum diameter on image. For 16 tumors, over 20 sequential CT images were taken every 2 s, with a 1-s acquisition time occurring during free breathing. For each tumor, the distance between the surface of the CT table and the posterior border of the tumor was measured to determine whether the edge of the tumor was sufficiently included in the planning target volume (PTV) during normal breathing.
In the sequential CT scanning, the tumor itself was not visible in the examination slice in 21% (75/357) of cases. There were statistically significant differences between lower lobe tumors (39.4%, 71/180) and upper lobe tumors (0%, 0/89) (p < 0.01) and between lower lobe tumors and middle lobe tumor (8.9%, 4/45) (p < 0.01) in the incidence of the disappearance of the tumor from the image. The mean difference between the maximum and minimum distances between the surface of the CT table and the posterior border of the tumor was 6.4 mm (range 2.1-24.4).
Three-dimensional treatment planning for lung carcinoma would significantly underdose many lesions, especially those in the lower lobe. The excess "safety margin" might call into question any additional benefit of 3D treatment. More work is required to determine how to control respiratory movement.
International Journal of Radiation OncologyBiologyPhysics 04/2000; 46(5):1127-33. · 4.11 Impact Factor
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ABSTRACT: To reduce xerostomia in selected patients with carcinomas of the tonsillar region and soft palate.
We evaluated the treatment results of 32 patients with tonsillar region and soft palate carcinoma treated by radical radiotherapy between May 1989 and December 1996. They have a unilateral tumor that did not cross midline and have no contralateral neck lymphnode metastasis and treated with an ipsilateral technique (an anterior oblique and a posterior oblique field). All patients were planned with computed tomographic (CT) simulation and given 65 Gy in 26 fractions in 6.5 weeks with or without 5-15 Gy boost irradiation. The median follow-up was 44 months (4-86 months).
Five-year overall, cause-specific survival, local control, and regional control rate was 64, 79, 74 and 81%. No failure at the contralateral neck occurred. Moderate or severe symptomatic xerostomia was seen in 3 (9%) patients and ostero-radionecrosis requiring surgery occurred in one (3.3%) of 32 patients.
It is suggested that the ipsilateral technique is indicated in patients who had an unilateral tonsillar region or soft palate carcinoma that did not cross midline and have no contralateral neck lymphnode metastasis.
Radiotherapy and Oncology 03/2000; 54(2):117-21. · 5.58 Impact Factor
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ABSTRACT: In patients with thoracic esophageal carcinoma, radical dissection of the upper mediastinal lymph nodes often leads to complications such as recurrent laryngeal nerve palsy and subsequent pulmonary disorders. Intraoperative radiation therapy (IORT) to the upper mediastinum and nerve-sparing three-field lymphadenectomy followed by external beam radiotherapy has been developed to improve the locoregional control rate without resulting in these major postoperative complications.
Three-field lymphadenectomy, including cervical, mediastinal, and abdominal lymph node dissection, was performed. Dissection of the upper mediastinum was conservative to preserve recurrent laryngeal nerve function. IORT of 12-25 grays (Gy) was applied to the upper mediastinum. Postoperative radiation therapy (PORT) of 45 Gy in 16 fractions over 4 weeks was applied to the entire neck and upper mediastinum using an external X-ray beam. Between 1989-1996, 121 patients with thoracic esophageal carcinoma underwent surgery and received IORT, and 103 of these patients underwent PORT as part of their treatment schedule.
The surgical mortality rate was 0.8% (1 of 121 cases). The overall 5-year survival rate was 34.4% and the cause specific 5-year survival rate was 54.8%. The cause specific 5-year survival rate for pN0 tumors was 79.4% and was 43.8% for pN1 tumors. No patients died with locoregional recurrence in the mediastinal lymph nodes. Recurrent laryngeal nerve palsy was observed in 25 patients (21%), but the palsy remained for > 1 month in only 13 patients (11%). Mechanical ventilation support for > 48 hours was required for 22 patients (18.2%). Fatal tracheal ulcers occurred in 4 of 18 patients who received the highest IORT dose of 25 Gy.
Three-field lymphadenectomy to preserve recurrent laryngeal nerves and IORT using 12-20 Gy followed by 45-Gy PORT effectively reduced locoregional recurrence, recurrent laryngeal nerve palsy, and pulmonary complications caused by radical surgical dissections. The minimally effective dose of IORT appears to be < or = 15 Gy, a factor that will be further evaluated with longer follow-up.
Cancer 07/1999; 86(1):6-13. · 4.77 Impact Factor
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ABSTRACT: We have shown that metastasis is suppressed by low-dose total-body irradiation (TBI) in tumor-bearing rats. We have evaluated the immunological effects of low-dose TBI. Total-body irradiation with 0.2 Gy was given 14 days after the implantation of 5 x 10(5) allogenic hepatoma cells (KDH-8) which produce transforming growth factor beta (TGF-beta). On day 21, the splenocytes and tumor-tissue infiltrating lymphocytes were analyzed by FACScan and RT-PCR for the mRNA of the genes that encode tumor necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma), TGF-beta, interleukin (IL)-4, IL-10 and IL-6. The same procedure was conducted with untreated rats and with rats that underwent local irradiation with 0.2 Gy. The low-dose TBI significantly decreased the incidence of lung and lymph node metastasis (P < 0.01), whereas the same dose of local irradiation had no effect on the incidence of metastasis. The proportion of CD8+ cells in splenocytes increased in the low-dose TBI group (P < 0.01) compared to the locally irradiated and the untreated groups. The tumor-tissue infiltrating lymphocytes were also significantly increased after low-dose TBI (P < 0.01). The FACScan analysis revealed that 72% of the tumor-tissue infiltrating lymphocytes were CD8+. In both spleen and tumor tissue after low-dose TBI, mRNA expression of the genes that encode IFN-gamma and TNF-alpha increased, while that of the Tgfb gene decreased. There was no expression of the mRNAs of the Il4, Il6 and Il10 genes. CD8+ cells and the cytokine network may play an important role in the antitumor effect of low-dose TBI.
Radiation Research 06/1999; 151(6):717-24. · 2.68 Impact Factor
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ABSTRACT: The authors evaluated the effect of hepatic venous occlusion on hepatic arterial embolization in rats.
A Lipiodol-Iopamidol mixture was injected into the proper hepatic artery in rats during clamping the right side of the hepatic venous confluence. The distribution of Lipiodol-Iopamidol mixture in the sinusoids was analyzed by histological examination with en bloc silver impregnation. The extent of the distribution of Lipiodol-Iopamidol mixture was compared in sinusoids with hepatic venous occlusion and in sinusoids without hepatic venous occlusion.
Lipiodol-Iopamidol mixture was more widely distributed in the lobules with hepatic venous occlusion than in the lobules without occlusion.
Hepatic venous occlusion may enhance the effect of hepatic arterial embolization using Lipiodol emulsions and could be useful in the treatment of hepatocellular carcinoma.
Investigative Radiology 06/1999; 34(5):341-7. · 4.59 Impact Factor
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ABSTRACT: Three-dimensional (3D) movement of a spherical liver tumor during respiration was investigated with magnetic resonance imaging (MRI) using a high-speed sequence.
A marker was placed on the surface of the patient as a reference of distance. Repetition time (TR) was 7.7 ms, echo time (TE) was 4.2 ms, flip angle was 20 degrees, section thickness was 8 mm, and a 256 x 128 matrix was used. The acquisition time was 1.0 s followed by an interval of 0.5 s. The 20 tumor contours extracted during 30 s were superimposed on sagittal and coronal MR images.
The maximum value of tumor edge location was 3.9 cm in the cranio-caudal direction, 2.3 cm in the ventro-dorsal direction, and 3.1 cm in the lateral direction. The mean length of tumor displacement observed was 2.1 cm in the cranio-caudal direction, 0.8 cm in the ventro-dorsal and 0.9 cm in the left-right direction, respectively. The locus of the center of the tumor contour in the sagittal cross section was inclined at 23 degrees and in the coronal cross section was inclined at 18 degrees to the cranio-caudal axis of body.
In conclusion, 3D movement of a spherical liver tumor was detected using rapid MRI sequential examinations. Magnetic resonance imaging has a potential to improve the accuracy of the planning target volume of a liver tumor.
Radiotherapy and Oncology 04/1999; 50(3):367-70. · 5.58 Impact Factor
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ABSTRACT: To assess the efficacy and toxicity of small-field fractionated radiotherapy with or without stereotactic boost (SB) for vestibular schwannomas.
Thirty-nine patients with vestibular schwannoma were treated with irradiation between March 1991 and February 1996. Extra-meatal tumor diameters were under 30 mm. Thirty-three patients received small-field fractionated radiotherapy followed by SB. Basic dose schedule was 44 Gy in 22 fractions over 5 1/2 weeks plus 4 Gy in one session. Six patients received small-field fractionated radiotherapy only (40-44 Gy in 20-22 fractions over 5-5 1/2 weeks or 36 Gy in 20 fractions over 5 weeks).dash;p >
Follow-up ranged from 6 to 69 months (median, 24 months). Tumors decreased in size in 13 cases (33%), were unchanged in 25 (64%), and increased in one (3%). The actuarial 2-year tumor control rate was 97%. Fifteen patients had useful hearing (Gardner-Robertson class 1-2) and 25 patients had testable hearing (class 1-4) before irradiation. The 2-year actuarial rates of useful hearing preservation (free of deterioration from class 1-2 to class 3-5) were 78%. The 2-year actuarial rates of any testable hearing preservation (free of deterioration from class 1-4 to class 5) were 96%. No permanent facial and trigeminal neuropathy developed after irradiation. The 2-year actuarial incidences of facial and trigeminal neuropathies were 8% and 16%, respectively.
Small-field fractionated radiotherapy with or without SB provides excellent short-term local control and a relatively low incidence of complications for vestibular schwannoma, although further follow-up is necessary to evaluate the long-term results.
Radiotherapy and Oncology 03/1999; 50(3):341-7. · 5.58 Impact Factor
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Y Hosokawa,
H Shirato,
K Kagei, S Hashimoto,
T Nishioka,
K Tei,
M Ono,
K Ohmori,
M Kaneko,
K Miyasaka,
M Nakamura
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ABSTRACT: This report analyzes 61 patients with mucoepidermoid carcinomas of the salivary gland treated by surgery alone or by surgery plus radiotherapy. Local control for all 61 patients at 5 and 10 years was achieved for 88.8 and 79.7% of the cases. Although the rate of positive surgical margin was higher in patients treated with surgery and radiotherapy (radiotherapy group) than in patients treated by surgery alone (surgery group), the local control rates of the two groups showed no statistically significant differences. There was no local recurrence in seven patients receiving post-operative radiotherapy above 55 Gy while there were three local relapses among 17 patients receiving 55 Gy or lower doses (P < 0.05). The 5- and 10-year actual survival rates were 73.4 and 63.3% respectively. Histopathologic subtype of mucoepidermoid carcinomas correlated with regional lymph node involvement and survival. There were no differences in the local control and survival rates of patients with major salivary gland tumors and patients with minor salivary gland tumors. Radiotherapy using 55 Gy or more combined with operation achieved local control and survival rates comparable with complete resection of tumors even if a positive surgical margin was more frequent in the radiotherapy groups.
Oral Oncology 01/1999; 35(1):105-11. · 2.86 Impact Factor
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ABSTRACT: We studied 30 patients with early stage malignant lymphomas involving the nasal cavity and/or paranasal sinus who were treated between 1972 to 1991 in Hokkaido University Hospital. The mean age of the patients was 60.6 yr, and the male-to-female ratio was 2.6. The predominant histologic type was diffuse large cell type (n = 23). Treatment policy differed depending on time: radiotherapy (RT) alone between 1972 and 1980 (n = 15), RT followed by modified CVP or CHOP between 1981 and 1988 (n = 10) and BACOP followed by RT between 1989 and 1991 (n = 5). Overall five-year survival was 53%. Better survival was observed in patients with B-cell type (72%), smaller mass (tumor limited to the unilateral nasal cavity or paranasal sinus) (76%), and patients who were treated with combination chemotherapy (BACOP) followed by RT (100%). Eleven patients experienced recurrence. Four of nine local recurrences were in patients with T-cell lymphoma. CNS relapse was observed in three patients with T-cell lymphoma. We conclude that T-cell lymphoma arising at the nasal cavity and/or paranasal sinus needs careful follow-up for its high frequency of local and CNS relapse. More intensive treatment such as prophylactic whole brain RT, intrathecal administration of MTX or third generation chemotherapy (e.g. MACOP-B) might improve survival in these patients.
Nihon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica 07/1993; 53(6):679-87.
