Enfoque oncoplástico en el tratamiento quirúrgico conservador del cáncer de mama. Una revisión bibliográfica / Oncoplastic approach in the conservative surgical treatment of breast cancer. A bibliographic review

Introducción: El cáncer de mama es el más común en el mundo y constituye la principal causa de muerte en mujeres, no obstante, los avances terapéuticos han permitido aumentar sus tasas de supervivencia global, libre de enfermedad. Procurando una mejor calidad de vida surge la cirugía oncoplástica, que combina la cirugía plástica y reconstructiva en el ma-nejo quirúrgico del cáncer de mama localmente avanzado, de mayor tamaño o con ubicación desfavorable, buscando mejorar el resultado estético sin perjuicio del resultado oncológico. Objetivo: Realizar una revisión bibliográfica actualizada del enfoque oncoplástico en el tra-tamiento quirúrgico conservador del cáncer de mama, con el propósito de conocer sus re-sultados oncológicos y estéticos en comparación con los tratamientos quirúrgicos conven-cionales.Material y Métodos: La búsqueda bibliográfica se llevó a cabo en las bases de datos Pub-Med, Elsevier, Hinari, Cochrane y ScienceDirect. Seleccionando los artículos publicados du-rante los últimos 10 años, en inglés o español, que tuvieron relación con información relevan-te en el tratamiento quirúrgico oncoplástico conservador del cáncer de mama.Resultados: Los criterios de búsqueda incluyeron artículos sobre el tratamiento quirúrgico oncoplástico conservador en mujeres con cáncer de mama primario, 99 artículos cumplie-ron los criterios, excluyéndose aquellos publicados hace más de 10 años, con metodología poco clara o no reproducible. Fueron elegibles 35 por ser relevantes al tema, publicados en revistas indexadas entre los años 2011 y 2021, permitiendo determinar los resultados clíni-cos, oncológicos y estéticos de la cirugía oncoplástica conservadora y contrastarlos con las técnicas convencionales. Conclusión: La cirugía oncoplástica conservadora de mama es oncológicamente segura y equiparable a las cirugías convencionales (mastectomía total o parcial), ofreciendo resulta-dos estéticos más satisfactorios y mejorando la calidad de vida de las pacientes.

Background: Breast cancer is the most common cancer in the world and represents the main cause of death in women; nevertheless, therapeutic advances have made it possible to increase overall and disease-free survival rates. Looking for a better quality of life, on-coplastic surgery arises, which combines plastic and reconstructive surgery in the surgical management of locally advanced breast cancer, larger or with unfavorable location, seeking to improve the appearance without affecting the oncologic result.Objective: To perform an updated bibliographic review of the oncoplastic approach in the conservative surgical treatment of breast cancer, with the purpose of knowing its oncologic and esthetic results compared to conventional surgical treatments.Material and Methods: The bibliographic search was carried out in the databases PubMed, Elsevier, Hinari, Cochrane and ScienceDirect. Selecting the articles published during the last 10 years, in either English or Spanish, that were related to relevant information in the conser-vative oncoplastic surgical treatment of breast cancer.Results: The search criteria included articles on conservative oncoplastic surgical treatment in women with primary breast cancer, 99 articles met the criteria, excluding those published more than 10 years ago, with unclear or non-reproducible methodology. 35 were eligible, because they were relevant to the subject, published in indexed journals between 2011 and 2021, allowing to determine the clinical, oncological and aesthetic results of conservative oncoplastic surgery and contrast them with conventional techniques. Conclusion: Oncoplastic breast-conserving surgery is oncologically safe and comparable to conventional surgeries (total or partial mastectomy), offering more satisfactory esthetic results and improving the quality of life in patients.

Sonography Guided Percutaneous Radiofrequency Ablation of Hepatocellular Carcinoma: Effect of Cooperative Training on the Pretreatment Assessment of the Operation's Feasibility

OBJECTIVE: The aim of this study is to investigate the effects of cooperative training on the pretreatment assessment of the feasibility to perform Ultrasonography (US) guided percutaneous radiofrequency ablation for patients afflicted with hepatocellular carcinoma. MATERIALS AND METHODS: In our prospective study, 146 patients with 200 hepatocellular carcinomas were referred for radiofrequency ablation after triage by hepatologists. Three radiologists with different levels of experience performed the planning US before (group I) and after (group II) cooperative training, to evaluate whether radiofrequency ablation was feasible. The feasibility rates considered eligible according to our criteria were evaluated. In addition, we analyzed the reasons for the lack of feasibility were analyzed. The interobserver agreement for the assessment of feasibility before and after training was also calculated. RESULTS: The overall feasibility rates for both groups was 73%. No significant difference in the feasibility rates was observed. The feasibility rates of each observer for group I were 71% (observer 1), 77% (observer 2) and 70% (observer 3) and those for group II were 73%, 76% and 69%, respectively. In the tumors (n = 164) considered ineligible, the two most common causes for refraining from performing radiofrequency ablation included non-visualization of the tumor (62%) and the absence of a safe route for the percutaneous approach (38%). We found moderate interobserver agreement for all observers before cooperative training and a good agreement after training. CONCLUSION: Although the cooperative training did not affect the feasibility rate of each observer, it improved the interobserver agreement for assessing the feasibility of performing US guided radiofrequency ablation, which may reduce unnecessary admission or delayed treatment.

MR Imaging of Endometrial Cancer that Occurs After Radiation Therapy for Cervix Cancer

PURPOSE: We wanted to describe the MR imaging findings of endometrial cancer in patients with a history of prior radiation therapy for cervical cancer (ECRT) and we compare them to the MR imaging findings of patients with spontaneously occurring endometrial cancer (SEC). MATERIALS AND METHODS: Twenty-two patients with endometrial cancer that was diagnosed by operation or endometrial biopsy were included in the study. The patients were divided into two groups according to the presence of past RT for cervical cancer: ECRT (n = 4) and SEC (n = 18). The MR images were retrospectively analyzed by consensus of two experienced radiologists. The MR imaging findings were analyzed by the size, shape and signal intensity of the mass, distension of the uterine cavity, the presence of cervical stenosis and the nature of the fluid collection. RESULTS: For the mass shape, all the ECRT lesions were polypoid masses. However, the SEC patients had 5 polypoid masses and 13 wall thickenings. The maximal diameter, signal intensity and enhancement pattern of the masses were not different between the ECRT and SEC patients. The width of the endometrial cavity varied between 3.9 cm in the ECRT patients and 0.4 cm in the SEC patients (p =0.002). All the ECRT patients had cervical stenosis. However, none of the SEC patients had cervical stenosis. CONCLUSION: MR imaging of ECRT patients demonstrated prominent distension of their uterine cavity and cervical stenosis, which may be the result of radiation fibrosis in the uterus.

FDG-PET for Evaluating the Antitumor Effect of Intraarterial 3-Bromopyruvate Administration in a Rabbit VX2 Liver Tumor Model

OBJECTIVE: We wanted to investigate the feasibility of using FDG-PET for evaluating the antitumor effect of intraarterial administration of a hexokinase II inhibitor, 3-bromopyruvate (3-BrPA), in a rabbit VX2 liver tumor model. MATERIALS AND METHODS: VX2 carcinoma was grown in the livers of ten rabbits. Two weeks later, liver CT was performed to confirm appropriate tumor growth for the experiment. After tumor volume-matched grouping of the rabbits, transcatheter intraarterial administration of 3-BrPA was performed (1 mM and 5 mM in five animals each, respectively). FDG-PET scan was performed the day before, immediately after and a week after 3-BrPA administration. FDG uptake was semiquantified by measuring the standardized uptake value (SUV). A week after treatment, the experimental animals were sacrificed and the necrosis rates of the tumors were calculated based on the histopathology. RESULTS: The SUV of the VX2 tumors before treatment (3.87+/-1.51[mean+/-SD]) was significantly higher than that of nontumorous liver parenchyma (1.72+/-0.34) (p < 0.0001, Mann-Whitney U test). The SUV was significantly decreased immediately after 3-BrPA administration (2.05+/-1.21) (p = 0.002, Wilcoxon signed rank test). On the one-week follow up PET scan, the FDG uptake remained significantly lower (SUV 1.41+/-0.73) than that before treatment (p = 0.002), although three out of ten animals showed a slightly increasing tendency for the FDG uptake. The tumor necrosis rate ranged from 50.00% to 99.90% (85.48%+/-15.87). There was no significant correlation between the SUV or the SUV decrease rate and the tumor necrosis rate in that range. CONCLUSION: Even though FDG-PET cannot exactly reflect the tumor necrosis rate, FDG-PET is a useful modality for the early assessment of the antitumor effect of intraarterial administration of 3-BrPA in VX2 liver tumor.

High-intensity Focused Ultrasound Treatment (HIFU) for the Advanced Pancreatic Cancer

PURPOSE: We wanted to evaluate the levels of effect and safety of high-intensity focused ultrasound ablation (HIFU) for treating patients with advanced pancreatic cancer. MATERIALS AND METHODS: Nineteen sessions of HIFU, with the patients under general anesthesia, were performed in 18 patients with advanced pancreatic cancer. The change of the gray-scale of the target lesion was analyzed during HIFU, and MRI was performed before and after HIFU. We assessed the extent of coagulative necrosis, the change of pain and the complications after HIFU. The change of tumor size and the survival of patients were also evaluated. RESULTS: The average size of tumor was 4 cm in diameter. Eighty nine percent of the target tumors showed increased echogenicity. On MRI, necrosis of the entire target tumor occurred in 79% of the patients. After treatment, effective pain relief was noted in 89% of the patients. There were no major complications. No size increase of the treated tumor was noted during 24 weeks of follow-up for 10 patients. Six patients among 12 patients who were available for follow-up are still alive and they are receiving chemotherapy. Six patients expired due to other disease or progression of metastasis. CONCLUSION: HIFU is a safe method without any major complications, and it is effective for inducing tumor necrosis and achieving pain control for patients with advanced pancreatic cancer.

Citation Trend and Suggestions for Improvement of Impact Factor of Journal of Korean Therapeutic Radiology and Oncology / 대한방사선종양학회지

PURPOSE: To analyze the recent citation trend and to find a way to improve impact factor (IF) of the Journal of Korean Therapeutic Radiology and Oncology (JKSTRO) by analysis of Korean Medical Citation Index (KoMCI) citation data of JKSTRO and comparison with that of mean citation data of all journals enlisted on KoMCI (KoMCI journals) during 2000-2005. MATERIALS AND METHODS: All citation data of entire journals enlisted on KoMCI and JKSTRO from 2000 to 2005 were obtained from KoMCI. The trend of total and annual number of published articles and reference citations, total citations and self-citations per paper, IF and impact factor excluding self-citations (ZIF) were described and compared on both KoMCI journals and JKSTRO. RESULTS: Annual number of published articles was decreased for 6 years on both KoMCI journals and JKSTRO (32% and 38% reduction rate). The number of Korean journal references per article is 1.6 papers on JKSTRO comparing to 2.0 papers on KoMCI journals. The percentage of Korean references/total references increased from 5.0% in 2000 to 7.7% in 2005 on JKSTRO and from 8.5% in 2000 to 10.1% on KoMCI journals. The number of total citations received/paper on JKSTRO (average 1.333) is smaller than that of KoMCI journals (average 1.694), there was an increased rate of 67% in 2005 comparing to 2000. The percentage of self-citations/total citations (average 72%) on JKSTRO is slightly higher than that of KoMCI journals (average 61%). IF of JKSTRO was gradually improved and 0.144, 0.125, 0.088, 0.107, 0.187, and 0.203 in 2000-2005 respectively. However, ZIF of JKSTRO is steadily decreased from 0.038 in 2000 to 0.013 in 2005 except 0.044 in 2004. CONCLUSION: IF of JKSTRO was slightly improved but had some innate problem of smaller number of citations received. To make JKSTRO as a highly cited journal, the awareness of academic status of JKSTRO and active participation of every member of JKSTRO including encouraging self-citations of papers published recent 2 years and submission of English written papers, and active academic cooperation with related academic societies.

Metastatic Spinal Tumors: MR Findings after Novalis Radiosurgery

PURPOSE: To assess the therapeutic effect of Novalis radiosurgery for metastatic spinal tumors and evaluate the changes after treatment using MR imaging. MATERIALS AND METHODS: Between November 2003 and June 2005, 21 patients with metastatic spinal tumors underwent Novalis radiosurgery. Of these patients, the 7 with 13 metastatic spinal tumors who had undergone follow-up MR imaging were included in this study. The tumor locations were cervical spine in three, thoracic spine in four, lumbar spine in five and sacrum in one. During the first three months after Novalis radiosurgery, follow-up MRI was performed monthly and subsequently at 3-6-month intervals. On MR imaging, the volume of the tumors, the changes of their signal intensities and any changes in adjacent spinal cord were evaluated. RESULTS: Among the 13 lesions, 9 were decreased in volume (69.2%), 2 were stable (15.4%) and 2 were slightly increased. Seven of 9 lesions showed decreased signal intensity on T2 weighted images and 4 had compressive deformity. Two of 9 lesions had increased T2 signal intensity and tumor necrosis were detected on contrast-enhanced MR imaging. No changes in spinal cord were noted in any of the lesions. Those changes were detected on MRI obtained 1 month after Novalis surgery and the lesion sizes were gradually changed up to 3 months. CONCLUSION: Novalis radiosurgery was effective for the treatment of metastatic spinal tumor and the suppression of tumor growth. The estimation of therapeutic effect and detecting complication were precisely evaluated on MR imaging.

Transforaminal Epidural Steroid Injection for Lumbosacral Radiculopathy: Preganglionic versus Conventional Approach

OBJECTIVE: The present study was undertaken to evaluate the effectiveness of transforaminal epidural steroid injection (TFESI) with using a preganglionic approach for treating lumbar radiculopathy when the nerve root compression was located at the level of the supra-adjacent intervertebral disc. MATERIALS AND METHODS: The medical records of the patients who received conventional TFESI at our department from June 2003 to May 2004 were retrospectively reviewed. TFESI was performed in a total of 13 cases at the level of the exiting nerve root, in which the nerve root compression was at the level of the supra-adjacent intervertebral disc (the conventional TFESI group). Since June 2004, we have performed TFESI with using a preganglionic approach at the level of the supra-adjacent intervertebral disc (for example, at the neural foramen of L4-5 for the L5 nerve root) if the nerve root compression was at the level of the supra-adjacent intervertebral disc. Using the inclusion criteria described above, 20 of these patients were also consecutively enrolled in our study (the preganglionic TFESI group). The treatment outcome was assessed using a 5-point patient satisfaction scale and by using a VAS (visual assessment scale). A successful outcome required a patient satisfaction scale score of 3 (very good) or 4 (excellent), and a reduction on the VAS score of > 50% two weeks after performing TFESI. Logistic regression analysis was also performed. RESULTS: Of the 13 patients in the conventional TFESI group, nine showed satisfactory improvement two weeks after TFESI (69.2%). However, in the preganglionic TFESI group, 18 of the 20 patients (90%) showed satisfactory improvement. The difference between the two approaches in terms of TFESI effectiveness was of borderline significance (p = 0.056; odds ratio: 10.483). CONCLUSION: We conclude that preganglionic TFESI has the better therapeutic effect on radiculopathy caused by nerve root compression at the level of the supra-adjacent disc than does conventional TFESI, and the diffence between the two treatments had borderline statistical significance.

Radiocirugía estereotáxica con acelerador lineal (LINAC): Informe de la experiencia técnica en el manejo de 100 casos en el Hospital General de México / Stereotactic radiosurgery with linear accelerator (LINAC): Report of the technical experience in 100 cases treated at the Mexico General Hospital

La radiocirugía estereotáxica consiste en la liberación de una dosis única y grande de radiación a una lesión intracraneal, pequeña, bien definida y localizada estereotáxicamente. Objetivo: El objetivo de este estudio es detallar las consideraciones técnicas y correlacionarlas con los resultados clínicos, así como reportar los márgenes de dosis utilizados. Métodos: Fueron tratados 100 pacientes mediante radiocirugía estereotáxica con LINAC. Treinta y cuatro casos de malformaciones arteriovenosas, 22 meningiomas, 18 astrocitomas, 11 adenomas hipofisiarios, 5 angiomas cavernosos, 3 neurinomas del acústico, 3 craneofaringiomas, 2 casos de epilepsia, una metástasis cerebral y un ependimoma. Las dosis de radiación utilizadas variaron en cada caso. Variables estudiadas: respuesta de la lesión, toxicidad, dosis al volumen blanco, número de isocentros, número de arcos de tratamiento, número de colimadores, dosis a órganos riesgo, homogeneidad volumen blanco, margen de error, volumen blanco, diámetro de colimadores y localización del volumen blanco. Se realizó la prueba x² con significancia estadística p <0.05. La media seguimiento fue de 17.7 meses. Resultados: Se presentaron tres casos de toxicidad menor. Se confirmó que a mayor volumen blanco tratado será necesario mayor número de arcos de tratamiento, con amplio margen de error y mayor número de isocentros. Conclusión: La radiocirugía es un método seguro y confiable para el manejo de entidades patológicas benignas y malignas intracraneales.

Stereotactic radiosurgery consists of the release and high dose radiation inside the intracraneal, small, well defined and stereotactic localized injury. Objective: In this study we describe the technical aspects, clinical results and dose radiation levels used in 100 patients treated with LINAC. Methods: One hundred patients received treatment withe LINAC stereotactic radiosurgery, 34 AVM, 22 meningiomas, 18 astrocytomas, 11 pituitary adenomas, 5 cavernous malformations, 3 acoustic neuromas, 3 craniopharyngiomas, 2 cases of epilepsy, one brain metastases and one ependymoma. The radiation dose changed in each case. Studied variables: response of the injury, toxicity, in target dose, number of isocenters, number of treatment arcs, number of collimators, dose of risk organ, homogeneity of target, margin of error, target, diameter of collimator and location of target. We applied the %2 test with statistical significance of p < 0.05. Results: The median follow up was 17.7 months. We had 3 cases of minor toxicity. We confirmed that for a greater target volume, greater number oftreatment arcs were necessary, with greater margins of errors and greater number of isocenters. Conclusions: Radiosurgery is a safe and reliable technique to treat benign and malignant intracranial lesions.

Change of Ovary Before and After Radiotherapy in Reproductive Women with Cervix Carcinoma in MR Imaging

PURPOSE: To investigate changes in the ovary revealed by MR imaging before and after radiotherapy in premenopausal patients with cervical carcinoma. MATERIALS AND METHODS: Thirty-three premenopausal patients with cervical carcinoma underwent radiation therapy at an average dosage of 11,279 (external: 5,352; internal: 5,927) cGy. Before and after this therapy, all underwent pelvic MR imaging using a 1.5T MR scanner (GE Medical Systems, Milwaukee, U.S.A.). The average interval of follow-up MR imaging was 7.2 months, and axial T1-weighted and axial and sagittal T2-weighted MR images were obtained. The presence, size number of follicles, and differentiation of the zonal anatomy of the ovary were determined by two radiologists, who reached a consensus. RESULTS: After radiation therapy, all patients ceased menstruation. For ovaries, the detection rates before and after radiation therapy were 94% (62/66) and 39% (26/66) (p<0.05), respectively, and average ovary size was 2.6x1.9x2.2 cm before and 1.7x1.3x1.4 cm after therapy (p<0.05). The average number of ovarian follicles before and after therapy was 5.1 and 3.1, respectively (p<0.05). T2-weighted imaging, demonstrated differentiation of zonal anatomy in 74% of cases (46/62) before radiotheraphy, and 15% (4/26) after (p<0.05). CONCLUSION: Our study has shown that after radiation therapy in premenopausal patients with cervical cancer, detection rates, average size, and the number of ovaries decreased, findings which are similar to those for normal postmenopausal ovary. MR imaging can reveal structural change in ovaries.

Intraluminal Brachytherapy after Metallic Stent Placement in Primary Bile Duct Carcinoma

PURPOSE: To determine the effect of intraluminal brachytherapy on stent patency and survival after metallic stent placement in patients with primary bile duct carcinoma. MATERIALS AND METHODS: Twenty-seven patients with primary bile duct carcinoma underwent metallic stent placement; in 16 of the 27 intraluminal brachytherapy with an iridium-192 source (dose, 25 Gy) was the performed. Obstruction was due to either hilar (n=14) or non-hilar involvement (n=13). For statistical comparison of patients who underwent/did not undergo intraluminal brachytherapy, stent patency and survival were calculated using the Kaplan-Meier method and an independent t test. RESULTS: The mean durations of stent patency and survival were 9.1 and 10.0 months respectively in patients who underwent intraluminal brachytherapy, and 4.2 and 5.0 months in those who did not undergo this procedure (p<0.05). The mean durations of stent patency and survival among the 22 patients who died were 7.6 (range, 0.8 -16.1) and 8.3 (range, 0.8-17.3) months, respectively, in the eleven patients who underwent intraluminal brachytherapy, and 4.2 (range, 0.9-8.0) and 5.0 (range, 0.9-8.4) months in those whom the procedure was not performed (p<0.05). CONCLUSION: Intraluminal brachytherapy after stent placement extended both stent patency and survival in patients with primary bile duct carcinoma.

Changes of Intrathoracic Extrapulmonary Organs after Radiation Therapy for Lung and Esophageal Cancer: CT Findings

PURPOSE: To evaluate the CT findings and incidence of complications occurring in intrathoracic extrapul-monary organs due to radiation therapy. MATERIALS AND METHODS: Among 82 patients who underwent chest CT before and after radiation therapy, 23, in whom the procedure provided no evidence of pericardial invasion or pleural effusion before radiation therapy, nor of significant improvement in the tumor after this therapy, were evaulated. Changes in the pericardium, pleura and mediastinal fat were retrospectively assessed. In comparing the CT findings obtained before radiation therapy with those obtained afterwards, changes in the pericardium and pleura were classified as effusion where low density fluid was present and as thickening where there was no fluid. If an increased abundance of soft tissue strands was seen within mediastinal fat, changes in this fat were deemed to have occurred. RESULTS: Among the 23 patients evaluated, changes in the pericardium [thickening (n=3 ; 13.0%) ; effusion (n=8 ; 34.8%)] were found in 11 patients (47.8%), and changes in the pleura [thickening (n=3 ; 13.1%); effusion (n=9 ; 39.1%)] in 12 (52.2%). In no patient with pericardial or pleural effusion was thickening or contrast enhancement of the pericardium or pleura evident. In seven cases(30.4%), soft tissue strands within mediastinal fat had become more abundant. CONCLUSION: The CT findings which demonstrated complications resulting from radiation therapy were pericardial or pleural thickening or effusion and an increased abundance of soft tissue strands within mediastinal fat. In contrast to previous reports, pericardial and pleural change after radiation therapy was a common finding in our study, occurring in 69.6% of cases.

Evaluation of Therapeutic Effect of Acoustic Schwannoma After Gamma-Knife Radiosurgery using Follow-up MRI

PURPOSE: To evaluate, using short-term follow-up MR imagings, the usefulness of gamma-knife radiosurgery in patients with acoustic schwannoma. MATERIALS AND METHODS: In 34 patients (M:F=11:23, aged 11 -69 years) with acoustic schwannoma, eleven of whom had undergone microsurgical resection prior to gamma-knife radiosurgery, we retrospectively reviewed the serial MR imaging findings obtained before and after this procedure. Analysis focused on post-surgical changes in tumor volume and intratumoral enhancement, and the follow-up period ranged from 3 to 44 months. RESULTS: Follow-up imaging revealed that after radiosurgery, tumor size had decreased in 17 cases (50%), was unchanged in 14 (41.2%), and had increased in three (8.8%). Local tumor control was achieved in 31 of 34 cases (91.2%). Objectively defined tumor shrinkage was seen within 3 to 24 (median, 12) months of treatment, the rate of shrinkage increasing with longer follow-up. Three to 16 (median, 6) months after treatment, loss of central tumor enhancement was evident in 28 cases(82.4%). In 25 of 28 patients with intratumoral necrosis (89.3%), tumors were either smaller of their size was unchanged. Three to six (mean, 3.6) months after treatment, five cases demonstrated a transient size increase. CONCLUSION: Gamma-knife radiosurgery effectively controlled the growth of acoustic schwannoma, and intra-tumoral necrosis appears to be a predictable sign for decreased tumor size.

Evaluation of Therapeutic Effect of Acoustic Schwannoma After Gamma-Knife Radiosurgery using Follow-up MRI

PURPOSE: To evaluate, using short-term follow-up MR imagings, the usefulness of gamma-knife radiosurgery in patients with acoustic schwannoma. MATERIALS AND METHODS: In 34 patients (M:F=11:23, aged 11 -69 years) with acoustic schwannoma, eleven of whom had undergone microsurgical resection prior to gamma-knife radiosurgery, we retrospectively reviewed the serial MR imaging findings obtained before and after this procedure. Analysis focused on post-surgical changes in tumor volume and intratumoral enhancement, and the follow-up period ranged from 3 to 44 months. RESULTS: Follow-up imaging revealed that after radiosurgery, tumor size had decreased in 17 cases (50%), was unchanged in 14 (41.2%), and had increased in three (8.8%). Local tumor control was achieved in 31 of 34 cases (91.2%). Objectively defined tumor shrinkage was seen within 3 to 24 (median, 12) months of treatment, the rate of shrinkage increasing with longer follow-up. Three to 16 (median, 6) months after treatment, loss of central tumor enhancement was evident in 28 cases(82.4%). In 25 of 28 patients with intratumoral necrosis (89.3%), tumors were either smaller of their size was unchanged. Three to six (mean, 3.6) months after treatment, five cases demonstrated a transient size increase. CONCLUSION: Gamma-knife radiosurgery effectively controlled the growth of acoustic schwannoma, and intra-tumoral necrosis appears to be a predictable sign for decreased tumor size.

Pituitary Adenoma after the Gamma-Knife Radiosugery: correlation of MRI findings with clinical manifestation

PURPOSE: To evaluate changes in the MRI findings of pituitary adenoma after gamma-knife radiosurgery, and tocorrelate these with the clinical outcome. MATERIALS AND METHODS: We evaluated the MRI findings of 27 patientswith pituitary adenoma before and after gamma-knife radiosurgery. Their ages ranged from 16 to 69 years(M:F =8:19), and there were seven cases of microadenoma and 20 of macroadenoma. In 11 cases, the tumor was partiallyremoved before radiosurgery. The follow-up period ranged from three to 43 months. RESULTS: In two cases ofmicroadenoma, complete regression was seen after three and 12 months, respectively, with normalization of hormonelevels and the improvement of symptoms. Among the remaining cases, in which no volume change was noted, hormonelevels normalized in four. Among 20 cases of macroadenoma, volume reduction was seen in 18 patients and completeregression, in two. In cases in which the volume was reduced by 20%, the mean follow-up period was 6.6 months, andin cases in which this was 50%, the period was 15.3 months. On postenhanced T1W images, the most frequent patternswere rim enhancement (n=10;50%) and homogneous enhancement changed to rim enhancement (n=4;20%). In six of ninecases(66.7%) of hyperfunctioning macroadenomas, hormone levels normalized, and in nine of 11 cases (81.8%) ofnonfunctioning macroadenomas, symptom improvement was noted. In six of 20 cases in which the enhancement patternchanged after gamma knife radiosurgery, there was clinical improvement. Among 14 cases in which there was nochange in the enhancement pattern, nine showed clinical improvement but five did not. The former showed a meanvolume reduction of 62.5% and the latter, 16.5%. CONCLUSIONS: After gamma-knife radiosurgery, clinicalimprovement in microadenomas can be expected, regardless of volume change. The volume of macroadenomas decreasedand a rim enhancement pattern was observed after gamma-knife radiosurgery. A marked reduction in the volume of atumor, or a change in its enhancement pattern may indicate clinical improvement.