Fractionated stereotactically guided radiotherapy and radiosurgery in the treatment of functional and nonfunctional adenomas of the pituitary gland.

PURPOSE: We evaluated survival rates and side effects after fractionated stereotactically guided radiotherapy (SCRT) and radiosurgery in patients with pituitary adenoma. METHODS AND MATERIALS: Between 1989 and 1998, 68 patients were treated with FSRT (n = 63) or radiosurgery (n = 5) for pituitary adenomas. Twenty-six had functional and 42 had nonfunctional adenomas. Follow-up included CT/MRI, endocrinologic, and ophthalmologic examinations. Mean follow-up was 38.7 months. Seven patients received radiotherapy as primary treatment and 39 patients received it postoperatively for residual disease. Twenty-two patients were treated for recurrent disease after surgery. Mean total dose was 52.2 Gy for SCRT, and 15 Gy for radiosurgery. RESULTS: Overall local tumor control was 93% (60/65 patients). Forty-three patients had stable disease based on CT/MRI, while 15 had a reduction of tumor volume. After FSRT, 26% with a functional adenoma had a complete remission and 19% had a reduction of hormonal overproduction after 34 months' mean. Two patients with STH-secreting adenomas had an endocrinologic recurrence, one with an ACTH-secreting adenoma radiologic recurrence, within 54 months. Reduction of visual acuity was seen in 4 patients and partial hypopituitarism in 3 patients. None of the patients developed brain radionecrosis or radiation-induced gliomas. CONCLUSION: Stereotactically guided radiotherapy is effective and safe in the treatment of pituitary adenomas to improve local control and reduce hormonal overproduction.

The use of a standardized positioning support cushion during daily routine of breast irradiation.

PURPOSE: The use of positioning and immobilization techniques during external beam irradiation of the female breast is time consuming and expensive. The currently available standardized positioning devices are insufficient. For this reason, we designed a new and generally useable hard foam positioning support cushion for the use during breast irradiation, and tested its clinical usefulness in a prospective study. METHODS AND MATERIALS: Fifty-five female breast cancer patients receiving adjuvant radiotherapy following breast-conservative surgery were irradiated either without immobilization (n = 27) or with the positioning support cushion (n = 28). The time necessary for patient setup, the lying subjective comfort and--comparing portal images with simulator images--the reproducibility of the set up were determined. RESULTS: Irradiation reproducibility was significantly improved (average deviation without positioning support cushion: 8.4 mm, with positioning support cushion: 6.1 mm, p < 0.001). The time required for the positioning of the patient with positioning support cushion was in average 73 s, without cushion it was 55 s. A significantly higher proportion of patients (72%) found the position with the positioning support cushion as pleasant, whereas only 46% of patients were pleased with the position without cushion. CONCLUSION: The positioning support cushion designed in our department makes a substantial contribution to quality assurance in breast irradiation. It significantly increases the patients' comfort in a supine position. In contrast to conventional positioning and fixation aids it may be quickly and easily applied at low costs. Therefore, its use can be recommended.

Survival of very young children with medulloblastoma (primitive neuroectodermal tumor of the posterior fossa) treated with craniospinal irradiation.

PURPOSE: Very young children with medulloblastoma are considered to have a worse prognosis than older children. As radiotherapy remains an important part of the treatment, the adverse prognosis could be due to inadequate radiation treatment rather than biological factors. We analyzed the published literature to examine the impact of radiotherapy on survival in this group. METHODS AND MATERIALS: A Medline search was performed and we reviewed studies of treatment of medulloblastoma where radiotherapy was delivered using megavoltage equipment and the minimum follow-up allowed the calculation of 5-year survival rates. RESULTS: Thirty-nine studies were published between 1979 and 1996 with a treatment including craniospinal irradiation and boost to the posterior fossa. Eleven studies comprising 1366 patients analyzed survival by age at diagnosis. Eight of 11 studies showed a worse 5-year survival for the younger patient group which reached statistical significance in two. There is also a suggestion of a higher proportion of children with metastatic disease at presentation in the very young age group. The usual policy in younger children was to give a lower dose of radiotherapy to the craniospinal axis (CSA) and posterior fossa (PF) with reduction of dose in the range of 15 to 25% compared to standard treatment. As dose reduction to the posterior fossa is associated with worse survival and local recurrence is the predominant site of failure, the major determinant of worse survival in very young children with medulloblastoma may be suboptimal radiotherapy. Protocols including postoperative chemotherapy with delayed, omitted, or only local tumor irradiation do not reach survival rates of protocols with standard radiotherapy, also suggesting a continued importance for irradiation. CONCLUSION: Very young children with medulloblastoma have a worse prognosis than older children. Inadequate radiation dose and technique to the primary tumor region may be a major contributing factor. Current chemotherapeutic regimes alone are not sufficient to compensate for reduced radiation doses and volumes.

Increase of surface dose using wound dressings during percutaneous radiotherapy with photons and electrons.

Different wound dressings are used for the supportive treatment of patients with radiation-induced skin lesions. Depending on beam quality and energy, an increase of the dose administered to the skin and thus an aggravated skin reaction is to be expected during percutaneous irradiation. The increase of the skin dose during irradiation with photons (Co60, 6 MV, 42 MV) and electrons (7 MeV, 20 MeV, 42 MeV) was determined using thermoluminescence dosimetry. The use of wound dressings during electron irradiation and during soft irradiation therapy does not significantly increase the dose administered to the skin and does not therefore cause any problems. During irradiation with high energy photons only extremely thin dressings should be used; if there is an aggravated skin reaction, the dressing should be taken off before irradiation commences.

Influence of intra-fractional breathing movement in step-and-shoot IMRT.

Efforts have been made to extend the application of intensity-modulated radiotherapy to a variety of organs. One of the unanswered questions is whether breathing-induced organ motion may lead to a relevant over- or underdosage, e.g., in treatment plans for the irradiation of lung cancer. Theoretical considerations have been made concerning the different kinds of IMRT but there is still a lack of experimental data. We examined 18 points in a fraction of a clinical treatment plan of a NSCLC delivered in static IMRT with a new phantom and nine ionization chambers. Measurements were performed at a speed of 12 and 16 breathing cycles per minute. The dose differences between static points and moving target points ranged between -2.4% and +5.5% (mean: +0.2%, median: -0.1%) when moving with 12 cycles min(-1) and between -3.6% and +5.0% (mean: -0.4%, median: -0.6%) when moving with 16 cycles min(-1). All differences of measurements with and without movements were below 5%, with one exception. In conclusion, our results underline that at least in static IMRT breathing effects (concerning target dose coverage) due to interplay effects between collimator leaf movement and target movement are of secondary importance and will not reduce the clinical value of IMRT in the step-and-shoot technique for irradiation of thoracic targets.

Three-dimensional BANG gel dosimetry in conformal carbon ion radiotherapy.

In this study we applied BANG polymer-gel dosimetry using magnetic resonance imaging (MRI) to densely ionizing radiation such as carbon ion beams. BANG polymer gels were irradiated with a quadratic field of monoenergetic 12C ions at different beam energies in the range of 135 MeV u(-1) to 410 MeV u(-1). They were irradiated at the radiotherapy facility of the GSI, Darmstadt, Germany. Our object was to examine the saturation effect for densely ionizing radiation that occurs at high values of linear energy transfer (LET). The examination yielded the first effectiveness values that will be discussed in the following sections. A solid sphere and a hollow sphere were both irradiated with a horizontal pencil beam from the raster scanning facility at energies of 268 MeV u(-1) (solid sphere) and 304 MeV u(-1) (hollow sphere) respectively. MR dosimetry measurements were compared with data from a planning system. As far as quality is concerned, there is good agreement between the measured dose distributions of both samples and the dose maps from the planning software. The measured MR signals cannot be converted into absolute dose, since the relative efficiency is still unknown for mixed radiation fields of primary carbon ions and it is known only to a limited extent for nuclear fragments with different energies from highly energetic photon radiation. Model calculations are in progress in order to facilitate conversions of measured MR signals into dose.

Can prophylactic application of immunoglobulin decrease radiotherapy-induced oral mucositis?

Therapeutic application of immunoglobulin is reported to be successful in radiation-induced oral and oropharyngeal mucositis. In this study the efficacy of prophylactic application of immunoglobulin was investigated. In 42 patients with head and neck cancer, postoperative radiation treatment or radiation combined with chemotherapy was performed. In 20 consecutive patients, prophylactic mucositis treatment consisted of panthenol (4 x 10 ml/day) and nystatin (4 x 1 ml/day). The 22 following patients received, supplementary to panthenol and nystatin, 800 mg (5 ml) human immunoglobulin intramuscularly once weekly. During the treatment time, the degree of mucositis was examined 3 times a week. The distribution of maximal mucositis degree revealed slightly more severe mucous membrane reaction in the control group compared with the immunoglobulin group (n.s.). The analysis of mean mucositis degrees in both groups demonstrated statistically significant differences (t test, p = 0.031) related to the entire group (n = 42) and to those 16 patients receiving radiation combined with chemotherapy. There was no significant immunoglobulin-induced effect on mucositis in patients treated by radiation alone. The time from the beginning of therapy to the first interruption could be prolonged 5 days in the immunoglobulin group (n.s.). In conclusion, it is demonstrated that the prophylactic application of immunoglobulin seems to lower the degree of radiation-induced mucositis. In comparison to the published data about therapeutically given immunoglobulin, the clinical efficacy of the prophylactic application of immunoglobulin as it is performed in this study is less evident.

Bilateral breast carcinoma versus unilateral disease. Review of 498 patients.

In literature data, an uncertainty exists whether occurrence of bilateral breast cancer decreases the survival probability of affected patients. Therefore, we analyzed the medical records of 498 postoperatively irradiated (1977-1982) female breast cancer patients (T1-4,N0-3,M0). In the follow-up time, in 36 patients a bilateral breast carcinoma treated by surgery with or without radiotherapy was found. The 10-year overall survival rates were 54% in patients who had unilateral disease, compared with 56% in bilateral carcinoma patients, respectively. The incidence of metastasis did not differ between both groups: 24.2% versus 38.8%. Eleven percent of unilateral cancers recurred; in the other group, local failure of the first and second tumor was observed in 19.4% and 11.1%, respectively. We conclude that the occurrence of bilateral breast cancer has no significant impact on survival, although the development of local failures and metastases seems to be more frequent. The therapeutic strategy in bilateral carcinoma should resemble the treatment procedure in unilaterally affected patients.

Value of a multileaf prescription preparation system for palliative external beam irradiation.

In palliative treatment, irregularly shaped fields are used to reduce side-effects and can improve, or avoid, field matching. We investigated the effectiveness of a multileaf collimator (MLC) supported by a digitizing data entry system in the palliative radiotherapy treatment of 66 patients and compared it with conventional shielding with geometrically shaped blocks. After conventional simulation of rectangular fields, irregular field shapes were marked on the simulator film in 17 patients (27%) to reduce radiotherapy related side-effects. Individual leading was performed with an MLC. Digitizing and fitting of the optimum leaf position were carried out using a multileaf preparation system (MLP, Elekta, Crawley, UK). Target volumes included bone metastases in the pelvis, spine and extremities, mediastinal soft tissues, lymph nodes and central nervous system. In 10 patients, treated with a parallel pair for pelvic metastases, MLC and conventional shielding were prospectively compared with regard to time requirements and area shielded. Compared with conventional blocking, the mean simulation, preparation and treatment time required for MLP fields was shorter (9.55 +/- 1.44 min vs 16.90 +/- 2.64 min, and 5.50 +/- 1.14 min vs 8.97 +/- 1.75 min). The mean shielded area was 31 cm2 larger for MLC fields compared with geometrically shaped blocks (p < 0.05). Compared with cerrobend blocking, the use of an MLC, supported by preparation data entry software, is more flexible and reduces radiotherapy resources. Therefore, a preparation data entry system as a separate device, or integrated into the treatment planning system, is a useful tool in palliative treatment.

Comparison of forward planned conformal radiation therapy and inverse planned intensity modulated radiation therapy for esthesioneuroblastoma.

The purpose of this study was to compare dose distribution of inverse planned intensity modulated radiation therapy (IMRT) with that of conformal radiation therapy (SCRT) in the treatment of esthesioneuroblastoma, and to report initial clinical results. 13 patients with esthesioneuroblastoma were planned both with IMRT and SCRT using complete three-dimensional data sets. A target dose of 60 Gy was prescribed. We performed a detailed dose volume histogram analysis. Dose coverage was equal in both plans while dose distribution was more conformal to the target volume with IMRT. Mean and maximum dose of the brain stem, chiasm, optic nerves and orbits were lower using IMRT than SCRT. The reduction was significant regarding orbit and optic nerve (p<0.05). IMRT was superior in sparing of organs at risk compared with SCRT. The additional sparing by IMRT was positively correlated to the size of the target volume, which was evident with target volumes above 200 cm3. Treatment time was approximately 20 minutes per fraction using IMRT compared with 15 minutes per fraction using SCRT. We conclude that IMRT is both feasible and a valuable tool for more conformal dose distribution in the treatment of esthesioneuroblastoma and to spare organs at risk that are in critical relationship to the tumour. This advantage could be seen especially well in complex shaped target volumes above 200 cm3. Thus, using IMRT, risk of complications may be minimized and local tumour control may be increased.

In vivo dose increase in the presence of dental alloys during 60Co-gamma-ray therapy of the oral cavity.

During irradiation of the mouth cavity, dental metallic materials emit secondary electrons and thus increase the applied radiation dose in their vicinity. Therefore, local destruction of the mucous membrane contacting metallic dental crowns and fillings may be observed. Available data on this dose increase are based on measurements with beam arrangements perpendicular to the metallic surface. Since the dose modification depends on the beam direction in relation to specimen surface, a reliable prediction of dose modification in the close vicinity of dental caps on fillings under complex beam arrangements, as applied in the irradiation of head and neck region from the published data is not possible. Therefore, we measured dose increase in the immediate surrounding of metallic dental material using thermoluminescence dosimetry on the phantom and during routinely applied 60Co gamma ray therapy. Phantom measurements were carried out using several oblique irradiation angles and rotational therapy. In vivo measurements were carried out at alloy specimens containing gold, palladium, and amalgam in six patients and at permanently fixed golden teeth in five patients. In vivo, the following relative dose increase values according to a simultaneously measured reference value were obtained at the surface of different dental materials: 61% for fixed golden caps. 68% for the specimen containing gold, 33% for the specimen of palladium and 61% for the specimen of amalgam. The measured dose increases due to metallic dental material during routinely applied external 60Co beam irradiation are lower compared with those of perpendicular beam arrangements. Although, the extent of dose modification is less than expected, we still advocate protection of the oral mucosa to prevent painful lesion spots.

Kilovoltage CT using a linac-CT scanner combination.

Modern radiotherapy techniques such as intensity modulation are capable of generating complex dose distributions whose high dose areas tightly conform to the tumour target volume, sparing critical organs even when they are located in close proximity. This potential can only be exploited to its full extent when the accumulated dose actually delivered over the complete treatment course is sufficiently close to the dose computed on the initial CT scan used for treatment planning. Exact patient repositioning is mandatory, but also other sources of error, e.g. changes of the patient's anatomy under therapy, should be taken into account. At the German Cancer Research Center, we use a combination of a linear accelerator and a CT scanner installed in one room and sharing the same couch. It allows the quantification and correction of interfractional variations between planning and treatment delivery. In this paper, we describe treatments of prostate, paraspinal and head and neck tumours. All patients were immobilized by customized fixation devices and treated in a stereotactic setup. For each patient, frequent CT scans were taken during the treatment course. Each scan was compared with the original planning CT using manual checks and automatic rigid matching algorithms. Depending on the individual case, the adaptation to variations was carried out offline after several fractions or in real-time between the CT scan and linac irradiation. We discuss the techniques for detecting and correcting interfractional errors and outline the procedural steps of a linac-CT scanner-supported radiation treatment course.

Recurrent low-grade gliomas: the role of fractionated stereotactic re-irradiation.

PURPOSE: To assess the effectiveness of re-irradiation in recurrent low-grade gliomas (LGG). PATIENTS AND METHODS: Sixty-three patients were treated with fractionated stereotactic re-irradiation in the case of recurrent gliomas. At primary diagnosis of the tumor, the histology was grade II astrocytoma, oligodendroglioma or oligoastrocytoma. Fifty-two (82.5%) recurrences were in-field, three (4.8%) were localized at the field border, and eight (12.7%) tumors were localized completely out-field of the former RT field, respectively. Using three to four irregular non-coplanar fields formed with a multi-leaf-collimator, we applied a median total dose of 36 Gy (range 15-62 Gy)with a weekly fractionation of 5 x 2 Gy/week depending on the size and the location of the lesion. No concomitant chemotherapy was applied. RESULTS: Radiation was well tolerated by all patients. No severe side effects occurred. Median overall survival was 111 months (range 12-240 months). Extent of neurosurgical resection significantly influenced overall survival (P = 0.02). Median interval between the first radiation therapy and re-irradiation was 50 months (range 5-204 months). From the time point of re-irradiation, median survival was 23 months. Median progression-free survival from the time point of re-irradiation was 12 months (range 2-63 months). No prognosticators could be identified for survival from re-irradiation and progression free survival. CONCLUSION: Our retrospective data suggest that stereotactically guided fractionated re-irradiation in recurrent glioma represents an effective treatment option with good results and few complications. However, further investigation is warranted to consolidate these results and to combine radiation with chemotherapy in the case of recurrent LGG.

[The prognosis of bilateral breast carcinoma compared to unilateral breast tumor. 5- and 10-year follow-ups]. / Die Prognose des bilateralen Mammakarzinoms im Vergleich zum unilateralen Mammatumor. Follow-up nach fünf und zehn Jahren.

PURPOSE: A review of published data does not provide a certainty whether survival rates are comparable or worse in women with bilateral breast cancer versus patients with an unilateral tumor. Therefore results of therapy in one-sided and both-sided breast cancer were retrospectively analysed. PATIENTS AND METHODS: In a period from 1977 to 1982 (follow-up 5 to 12 years) 531 breast cancer patients with T1-4 N0-3 M0 tumors were treated with mastectomy (n = 416) and breast conserving therapy (n = 115). Postoperative radiotherapy was performed in all patients (50 Gy, 2 Gy/day 5 times/weekly; chest wall/breast and regional lymph nodes). Patients with positive lymph nodes received chemotherapy. Forty patients developed bilateral breast cancer (simultaneous n = 10, metachronous n = 30) that was treated by mastectomy (n = 28) and conservative surgery (n = 12), respectively, followed by radiotherapy in 26 women. RESULTS: Five- and 10-year survival was 74% and 56% in unilateral affected women. In 83% and 67% there were no metastases, respectively. Incidence of metastases was 27.9%. In bilateral breast cancer group survival rates were 85% and 59% and without evidence of metastases 87% and 60%, respectively. Distant disease was diagnosed in 35%. Differences between the 2 groups were statistically not significant. Whereas in time of follow-up 11% of unilateral cancer locally failed in bilateral cancer patients recurrences of the first and second tumor were seen in 20% and 10%, respectively. CONCLUSIONS: Survival of patients with bilateral breast cancer is not significantly decreased compared with unilateral disease although in patients with both-sided carcinoma local recurrences and metastases seem to occur more frequently.

[The value of conventionally fractionated radiotherapy in the local treatment of HIV-related Kaposi's sarcoma]. / Wertigkeit konventionell fraktionierter Radiotherapie bei der lokalen Behandlung des HIV-assoziierten Kaposi-Sarkoms.

BACKGROUND: During the course of AIDS, 25 to 44% of homosexual patients infected with the human immunodeficiency virus develop Kaposi's sarcoma. Main manifestation is the skin. Response rates of 80 to 100% can be achieved with total dosage up to 50 Gy. Nevertheless, remissions can also be attained with 20 Gy of fractionated radiotherapy. As clinical data on low dose conventional fractionated radiotherapy are insufficient we analysed the response rates of an overall dose of 20 Gy in conventional fractionation. PATIENTS AND METHODS: From June 1991 to June 1993, 43 patients with 111 HIV-associated Kaposi's sarcoma of the skin or oral cavity were treated. Lesions were irradiated with 5 to 12 MeV electrons or 60Co gamma-rays. The fractionation scheme was 5 times 2 Gy/week for skin and endoral lesions with a total reference dosage of up to 20 Gy. Side effects were assessed during therapy and the therapeutic result 6 weeks after end of treatment. RESULTS: Thirty-eight out of 111 lesions were judged as complete response (CR) (34%), 61/111 as partial response (PR) (55%) and 12/111 were judged as no change (NC) (11%). Overall response (CR + PR) was 89%. Two patients with lesions of oral cavity suffered from RTOG grade-IV mucositis after 10 and 14 Gy. In 71/106 skin lesions (67%), radiation induced RTOG grade-1 reactions were observed. CONCLUSION: In patients with HIV associated Kaposi's sarcoma effective palliation can be achieved by means of radiotherapy with an overall dose of 20 Gy in conventional fractionation. Yet, the fraction of patients with complete responses is with 34 to 47% lower compared with doses above 20 Gy (66 to 100%). With reference to the reported data our results point to a dose-response relationship for Kaposi's sarcoma. Therefore higher total reference doses, e.g. 30 Gy with weekly 5 times 2 Gy or 24 Gy with 5 times 1.6 Gy for mucous lesions, respectively, are suggested as by this mean the complete response rate can be doubled.

[Which factors modify the reproducibility of patient positioning in the daily irradiation routine?]. / Welche Faktoren beeinflussen die Reproduzierbarkeit der Patientenlagerung in der täglichen Bestrahlungsroutine?

AIM: Factors which influence the accuracy of the field application during daily irradiation routine are not well known. The aim of this prospective analysis was to determine the significance of these factors on the occurrence of field misadjustments in irradiation without immobilization and to evaluate their clinical relevance. PATIENTS AND METHODS: Fifty-three patients received external cobalt-60 beam irradiation without fixation. Once weekly portal images of all treatment fields were carried out. In addition to objective patient data (age, weight, height, general condition, irradiation indication), the psychological situation of the patient during treatment (anxiety, restlessness, pain) and work circumstances of the medical staff during treatment were evaluated once weekly. The distance of clearly visible anatomic structures to the field borders of the portal images were measured and the deviation to the corresponding simulator images was calculated. Patient data were correlated to the number of field misadjustments (deviation larger than 1 cm). RESULTS: Patients whose condition is generally poor and patients being treated palliatively, patients with feeling of anxiety, restlessness or pain during simulation or irradiation and heavy patients (90 kg and more) were more often misadjusted. The number of field misadjustments increased with the stress of the medical staff. CONCLUSIONS: The problem of reproducibility of external beam irradiation without fixation in palliative treatment is of clinical relevance. Effective analgesic therapy and a comfortable and painfree patient set-up reduce misadjustments. In curative treatment, immobilization techniques should be used.

Intensity-modulated radiotherapy with an integrated boost to the macroscopic tumor volume in the treatment of high-grade gliomas.

Integrated boost radiotherapy (IBRT) delivers a higher fraction size to the gross tumor volume and a conventional fraction size to the surrounding tissue of microscopic spread. We compared stereotactic conformal radiotherapy (SCRT) and intensity-modulated radiotherapy (IMRT) with regard to their suitability for IBRT in the treatment of high-grade gliomas. In 20 patients treated with conventional radiotherapy, an additional treatment plan for IBRT [planning target volume (PTV1) defined as contrast-enhancing lesion plus margin due to setup errors 75 Gy, PTV2 defined as edema plus margin due to microscopic spread and setup error 60 Gy] with 7 non-coplanar beams for IMRT and for SCRT was carried out and compared. The part of the PTV2 irradiated with more than 107% of the prescribed dose was 13.9% for IMRT and 30.9% for SCRT (P < 0.001). Dose coverage of PTV2 (volume above 95% of the prescribed dose) was improved with IMRT (88.4% vs. 75.3% with SCRT, P < 0.001). Dose coverage of PTV1 was slightly higher with SCRT (93.7% vs. 87.5% with IMRT), but the conformity to the boost shape was improved by IMRT [conformity index (COIN95) = 0.85 vs. 0.69 with SCRT]. Simultaneously the brain volume irradiated with > 50 Gy was reduced from 60 to 33 cc (P < 0.001). We conclude that IMRT is suitable for local dose escalation in the enhancing lesion and for delivering a homogeneous dose to the PTV2 outside the PTV1 at the same time. Our encouraging results justify application of IMRT for IBRT in the treatment of high-grade gliomas. For clinical evaluation a phase III study has been initiated.

Management of benign cranial nonacoustic schwannomas by fractionated stereotactic radiotherapy.

Schwannomas are the most common tumors of cranial nerves. Nonacoustic schwannomas are very rare tumors, accounting for approximately 10% of intracranial schwannomas. Standard treatment is complete surgical resection if possible. The role of fractionated stereotactic radiotherapy remains to be defined. Thirteen patients with cranial nonacoustic schwannomas underwent fractionated stereotactic radiotherapy. Seven patients had trigeminal schwannomas, three schwannomas of the lower cranial nerves, and three located in the cerebellopontine angle without involvement of the acoustic nerve. Treatment included primary or adjuvant radiotherapy in progressive disease. Tumor volume ranged from 4.5 to 76.0 cc (median 19.8 cc). Median dose was 57.6 Gy with 1.8 Gy/fraction. Median follow-up was 33 months (range 13-70 months). Local tumor control rate was 100% (13/13). Tumor size remained stable in nine patients and decreased in four. Improvement of preexisting neurological deficits was seen in four cases. No patient developed new cranial nerve or brain stem deficits. No patient showed clinically significant complications of irradiation. Fractionated stereotactic radiotherapy is an effective and well-tolerated noninvasive treatment for cranial nonacoustic schwannomas with excellent tumor control rates. It is an option for patients at higher risk for microsurgical resection or in residual and recurrent tumors.

[Radiotherapy planning for paraspinal tumors with CT-myelography]. / Bestrahlungsplanung rückenmarksnaher Tumoren unter Zuhilfenahme der CT-Myelographie.

BACKGROUND AND AIM: Artifacts due to metal implants are an important problem in diagnostic radiology and radiotherapy planning in tumors such as chordoma of the spine. A strict differentiation between target and radiosensitive structures e.g. spinal cord is absolutely essential for high-dose radiotherapy. Up to now CT and MRI techniques have provided only limited image quality in such situations. We introduce an approach to facilitate segmentation by using the technique of CT-myelography for radiation treatment. PATIENT AND METHOD: A 48-year-old woman with multiple inoperable relapses of a chordoma in the lumbar spine and extensive metal instrumentation in this area was given to radiotherapy using IMRT-technique (intensity modulated). MRI- and CT-planning images did not allow differentiation between myelon, cauda equina, dural sac and tumor. In this situation we performed a CT-myelography with the patient in treatment position. RESULT: CT-myelographic images enabled precise differentiation between myelon, cauda equina and intraspinal tumor. A substantial improvement of the segmentation of the spinal cord was obtained. There was no compression of the dural sac along the spine. This information provided the basis for a precise radiotherapy planning in IMRT-technique. CONCLUSION: In situations where CT- and MRI-techniques are not able to generate precise images which allow differentiation between tumor, myelon and cauda equina because of metal artifacts, CT-myelography is a promising technique which may help the diagnostic radiologist and radiation oncologist in planning radiotherapy.

[Improved reproducibility and comfort by standardized postural support in the irradiation of the female breast]. / Verbesserte Reproduzierbarkeit und erhöhter Komfort durch standardisierte Lagerungshilfe bei der Bestrahlung der weiblichen Brust.

BACKGROUND: Positioning and immobilisation techniques are essential for precise radiotherapy. The currently available standardised positioning devices are insufficient. For this reason, we designed a new and generally usable hard foam positioning support cushion for the breast irradiation and tested its usefulness in a prospective study. PATIENTS AND METHODS: Fifty-five female breast cancer patients receiving adjuvant radiotherapy following breast conservative surgery were irradiated either without immobilisation (n = 27) or with the developed positioning support cushion (n = 28). The time necessary for patient set-up, the subjective lying comfort and--comparing portal images with simulator images--the reproducibility of the set-up were determined. RESULTS: It was possible to improve irradiation reproducibility significantly (average deviation without positioning support cushion: 8.4 mm, with positioning support cushion: 6.1 mm, p < 0.001). The additional time required for the positioning of the patient was in average 19 s (with positioning support cushion: 74 s, without cushion: 55 s). A significantly higher proportion of patients (72%) found the position with the hard foam cushion was pleasant, whereas only 46% of patients were pleased with the position without cushion. CONCLUSION: The positioning support cushion designed in our department seems to play an important role in quality assurance of external beam irradiation of the breast and significantly increases the patients' comfort in a supine position. Compared to conventional positioning and fixation devices it may be quickly and easily applied at low cost. Therefore, its use can be recommended.