Laser interstitial thermal therapy for in-field recurrence of brain metastasis after stereotactic radiosurgery: does treatment with LITT prevent a neurologic death?

Brain metastasis (BM) affects up to one-third of adults with cancer and carries a historically bleak prognosis. Despite advances in stereotactic radiosurgery (SRS), rates of in-field recurrence (IFR) after SRS range from 10 to 25%. High rates of neurologic death have been reported after SRS failure, particularly for recurrences deep in the brain and surgically inaccessible. Laser interstitial thermal therapy (LITT) is an emerging option in this setting, but its ability to prevent a neurologic death is unknown. In this study, we investigate the causes of death among patients with BM who undergo LITT for IFR after SRS. We conducted a single institution retrospective case series of patients with BM who underwent LITT for IFR after SRS. Clinical and demographic data were collected via chart review. The primary endpoint was cause of death. Between 2010 and 2018, 70 patients with BM underwent LITT for IFR after SRS. Median follow-up after LITT was 12.0 months. At analysis, 49 patients died; a cause was determined in 44. Death was neurologic in 20 patients and non-neurologic in 24. The 24-month cumulative incidence of neurologic and non-neurologic death was 35.1% and 38.6%, respectively. Etiologies of neurologic death included local recurrence (n = 7), recovery failure (n = 7), distant progression (n = 5), and other (n = 1). Among our patient population, LITT provided the ability to stabilize neurologic disease in up to 2/3 of patients. For IFR after SRS, LITT may represent a reasonable treatment strategy for select patients. Additional work is necessary to determine the extent to which LITT can prevent neurologic death after recurrence of BM.

Assessment of the efficacy of Chinese patent medicine on treating pain caused by prostate cancer: A protocol for systematic review and meta analysis.

INTRODUCTION: With the development of economy and the acceleration of population aging, Prostate cancer (PCa) has presented a situation of high morbidity and mortality worldwide. The recent studies have shown that Chinese patent medicine combined with endocrine therapy in the treatment of prostate cancer not only plays a synergistic role in enhancing the efficacy. This review hopes to adopt meta-analysis to evaluate the efficacy and safety of Chinese patent medicine in the treatment of pain caused by prostate cancer and provides evidence for its application in clinical practice. METHODS AND ANALYSIS: We will search for PubMed, Cochrane Library, AMED, EMbase, WorldSciNet; Nature, Science online and China Journal Full-text Database (CNKI), China Biomedical Literature CD-ROM Database (CBM), and related randomized controlled trials included in the China Resources Database. The time is limited from the construction of the library to June 2019. We will use the criteria provided by Cochrane 5.1.0 for quality assessment and risk assessment of the included studies, and use the Revman 5.3 and Stata13.0 software for meta-analysis of the effectiveness, recurrence rate, and symptom scores of pain caused by prostate cancer. ETHICS AND DISSEMINATION: This systematic review will evaluate the efficacy and safety of Chinese patent medicine for pain caused by prostate cancer. Because all of the data used in this systematic review and meta-analysis has been published, this review does not require ethical approval. Furthermore, all data will be analyzed anonymously during the review process Trial. TRIAL REGISTRATION NUMBER: PROSPERO CRD42019131544.

Transsphenoidal versus Transcranial Approach for Treatment of Tuberculum Sellae Meningiomas: A Systematic Review and Meta-analysis of Comparative Studies.

There is controversy regarding the surgical route selection for tuberculum sellae meningiomas (TSMs): the transsphenoidal (TS) or transcranial (TC) approach? We conducted a systematic review and meta-analysis to compare clinical outcomes and postoperative complications between two surgical approaches. Literature search was performed. Relevant articles were selected and evaluated. Data were extracted and analyzed. Eight articles comprising 550 patients met the inclusion criteria. Traditionally, the rates of gross total resection, tumor recurrence, visual improvement, and cerebrospinal fluid leakage were the most common outcomes of interest. We demonstrated that the TS approach was significantly associated with better visual outcomes but more frequent cerebrospinal fluid leakage, while the rates of tumor resection and recurrence showed no significant difference between groups. In addition to surgical results that were consistent with previous studies, we further evaluated the impact of approach selection on common postoperative complications, which were closely related to the recovery course and quality of life. We revealed that the risk of dysosmia was significantly higher in the TS group. There was no significant difference between groups regarding infection, intracranial hemorrhage, and endocrine disorders. Because of the relatively low evidence levels of included retrospective studies, it was difficult to reach a categorical conclusion about the optimal surgical approach for TSMs. Finally, we recommended that the TS approach was an alternative option in patients with smaller TSMs (<30 mm) and limited invasion of optic canals in experienced neurosurgical centers.

Patterns of Fertility Preservation and Pregnancy Outcome After Breast Cancer at a Large Comprehensive Cancer Center.

BACKGROUND: In the last decades, long-term outcomes of breast cancer (BC) patients have improved, raising new survivorship issues, including fertility preservation and safety of pregnancy after BC. This study assesses evolution in patterns of fertility discussion/preservation over time and reports pregnancy outcomes in a cohort of young BC patients. METHODS: A retrospective cohort of 590 BC patients aged ≤40 diagnosed between 2000 and 2016 at a large cancer center was identified. Fertility counseling and preservation patterns for patients receiving chemotherapy were analyzed and compared for two cohorts: 2004-2006 and 2014-2016 (total n = 161). Outcomes were reported for patients with documented pregnancy after BC. RESULTS: Significantly, more patients diagnosed in 2014-2016 had evidence of discussion on fertility issues and/or application of fertility preservation techniques versus patients diagnosed in 2004-2006 (82.9% vs. 66.0%, p = 0.017). In particular, there was a significant difference in rate of documented fertility issues discussion (67.6% vs. 34.0%, p < 0.001). Age >35 and parity were associated with lower rates of fertility discussion/preservation. However, rates significantly improved over time (77.6% in 2014-2016 vs. 58.1% in 2004-2006 for patients aged >35, p = 0.046; 80.7% in 2014-2016 vs. 57.6% in 2004-2006 for patients with children at diagnosis, p = 0.018). Twenty-six patients with pregnancy after BC were identified; eight delivered at the age of >40. No complications for women or newborns were reported. Only two patients experienced BC relapse. CONCLUSIONS: In this small retrospective cohort, no safety concerns were identified for pregnancy after BC. The importance attributed by clinicians to address fertility issues has increased over time.

Survival benefit of conversion surgery for patients with initially unresectable pancreatic cancer who responded favorably to nonsurgical treatment.

BACKGROUND: Conversion surgery (CS) is expected as a new therapeutic strategy for patients with unresectable pancreatic cancer (UR-PC). We analyzed outcomes of CS for patients with UR-PC and evaluated the survival benefit of CS. METHODS: Thirty-four patients diagnosed with UR-PC according to the National Comprehensive Cancer Network guideline underwent CS in our hospital. Resectability was considered by multimodal images in patients who underwent nonsurgical treatment (NST) for more than 6 months. CS was performed only in patients who were judged to be able to undergo R0 resection. RESULTS: Twenty-six patients had locally advanced PC, and eight had distant metastases. The median duration of NST was 9 (range 5-44) months. R0 resection was achieved in 30 patients (88.2%). Six patients (17.6%) showed Evans grade ≥III. Three- and 5-year overall survival (OS) rates from initial treatment were 74% and 56.9%, respectively, with median survival time (MST) of 5.3 years. The actual 5-year OS rate in 19 patients was 47.4% with an MST of 4.0 years. Patients with Evans grade ≥III had a better prognosis than those with Evans grade

Systemic therapy in the curative treatment of head and neck squamous cell cancer: a systematic review.

OBJECTIVE: To review the available evidence and make recommendations regarding use of systemically administered drugs in combination or in sequence with radiation (RT) and/or surgery for cure and/or organ preservation in patients with locally advanced nonmetastatic (Stage III to IVB) squamous cell carcinoma of the head and neck (LASCCHN). METHOD: Recognizing the Meta-analysis of Chemotherapy in Head and Neck Cancer (MACH-NC) group reports have de facto guided practice since 2000, we searched for systematic reviews in the MEDLINE, EMBASE and Cochrane Database of Systematic Reviews published from January 2000 to February 2015 in reference to 4 research questions. A search was also conducted for randomized trials (RCTs) up to February 2015 not included in the meta-analyses. RESULT: The MACH-NC reports, 5 additional meta-analyses, and 30 RCTs not included by MACH-NC were identified. For chemotherapy, MACH-NC findings showing improved overall survival with concomitant chemoRT did not require modification. High-dose cisplatin was most commonly studied. We confirmed this benefit with cisplatin monotherapy in patients treated with with postoperative concurrent chemoRT. Other than cetuximab, no targeted agents and radiosensitizers studied in RCTs were shown effective. TPF induction chemotherapy was superior to PF for tumor response and larynx preservation but not survival. Larynx preservation was reported with both CRT and induction chemotherapy approaches. CONCLUSION: ChemoRT with cisplatin at least 40 mg/m2 per week given as radical or postoperative adjuvant remains a standard treatment approach for LASCCHN that improves overall survival but increases toxicity. 5-FU plus platinum is supported by less data but may be a reasonable alternative for patients unsuitable for cisplatin. Of note, stratification of outcomes by HPV-status was not available but outcomes for oropharynx cancer appeared similar to other subsites in chemoRT RCTs. No RCTs have yet demonstrated superiority or non-inferiority of cetuximab-RT to CRT. In view of this, cetuximab-RT is suggested only for patients not candidates for CRT. Taxane-based triplet induction chemotherapy is superior to doublets for rapid tumour downsizing and for larynx preservation, but does not improve overall survival and should be used with primary G-CSF prophylaxis. Further investigation of induction approaches for larynx preservation may be warranted.

Sentinel lymph node biopsy and aberrant lymphatic drainage in recurrent breast cancer: Findings likely to change treatment decisions.

BACKGROUND AND OBJECTIVES: It is not clear whether sentinel lymph node biopsy (SLNB) can be applied to patients with a second breast cancer or recurrence occurring at previously treated breast. The purpose of this study was to assess the feasibility of SLNB procedure in patients with recurrent breast cancer. METHODS: Patients with non-metastatic recurrent N0 breast cancer at ipsilateral breast were included. Patients were grouped according to their initial breast, axilla, and overall surgery. Presence of drainage and its pattern as well as SLNB success rate and overall axillary involvement rates were assessed. Findings were compared. RESULTS: Out of 75 patients, mean age was 52.5 years and disease-free interval was 82 (9-312) months. Lymphatic drainage was successful in 42 (56%) patients. Drainage positivity was more frequent in patients who were previously treated with SLNB (82.6%) than in patients who underwent axillary lymph node dissection (ALND) (44.2%; P = 0,002). Aberrant lymphatic drainage was detected in 64.3% of drainage positive patients. Success rate of reoperative SLNB was 92.9%. Adjuvant treatment plan was altered in 12 (16%) patients. In 15 patients, negative SLNB prevented axillary dissection. CONCLUSIONS: Reoperative SLNB seems to be technically feasible in N0 recurrent breast cancer patients. It may further avoid unnecessary ALND and lead changes in adjuvant treatment plans. J. Surg. Oncol. 2016;114:796-802. © 2016 2016 Wiley Periodicals, Inc.

Analysis of Geometric Shifts and Proper Setup-Margin in Prostate Cancer Patients Treated With Pelvic Intensity-Modulated Radiotherapy Using Endorectal Ballooning and Daily Enema for Prostate Immobilization.

We evaluate geometric shifts of daily setup for evaluating the appropriateness of treatment and determining proper margins for the planning target volume (PTV) in prostate cancer patients.We analyzed 1200 sets of pretreatment megavoltage-CT scans that were acquired from 40 patients with intermediate to high-risk prostate cancer. They received whole pelvic intensity-modulated radiotherapy (IMRT). They underwent daily endorectal ballooning and enema to limit intrapelvic organ movement. The mean and standard deviation (SD) of daily translational shifts in right-to-left (X), anterior-to-posterior (Y), and superior-to-inferior (Z) were evaluated for systemic and random error.The mean ±â€ŠSD of systemic error (Σ) in X, Y, Z, and roll was 2.21 ±â€Š3.42 mm, -0.67 ±â€Š2.27 mm, 1.05 ±â€Š2.87 mm, and -0.43 ±â€Š0.89°, respectively. The mean ±â€ŠSD of random error (δ) was 1.95 ±â€Š1.60 mm in X, 1.02 ±â€Š0.50 mm in Y, 1.01 ±â€Š0.48 mm in Z, and 0.37 ±â€Š0.15° in roll. The calculated proper PTV margins that cover >95% of the target on average were 8.20 (X), 5.25 (Y), and 6.45 (Z) mm. Mean systemic geometrical shifts of IMRT were not statistically different in all transitional and three-dimensional shifts from early to late weeks. There was no grade 3 or higher gastrointestinal or genitourianry toxicity.The whole pelvic IMRT technique is a feasible and effective modality that limits intrapelvic organ motion and reduces setup uncertainties. Proper margins for the PTV can be determined by using geometric shifts data.

Oropharyngeal squamous cell carcinoma in the veteran population: Association with traditional carcinogen exposure and poor clinical outcomes.

BACKGROUND: A significant fraction of oropharyngeal squamous cell carcinoma (SCC) cases is associated with traditional carcinogens; in these patients, treatment response and clinical outcomes remain poor. METHODS: We evaluated patient, tumor, and treatment characteristics for 200 veterans with oropharyngeal SCC treated at the Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC) between 2000 and 2012. RESULTS: Most patients (77%) were white and heavy smokers. Twenty-seven patients required tracheostomy and 63 required gastrostomy placement during treatment. Overall survival (OS) at 5 years was 40%. Survival was impacted by T classification, treatment intensity, completion of treatment, and p16 tumor status. Almost 30% of patients were unable to complete a treatment regimen consistent with National Comprehensive Cancer Network (NCCN) guidelines. CONCLUSION: Oropharyngeal SCC in veterans is associated with traditional carcinogens and poor clinical outcomes. Despite heavy smoking exposure, p16 tumor status significantly impacts survival. Careful consideration must be given to improving treatment paradigms for this cohort given their limited tolerance for treatment escalation.

Using natural language processing to improve efficiency of manual chart abstraction in research: the case of breast cancer recurrence.

The increasing availability of electronic health records (EHRs) creates opportunities for automated extraction of information from clinical text. We hypothesized that natural language processing (NLP) could substantially reduce the burden of manual abstraction in studies examining outcomes, like cancer recurrence, that are documented in unstructured clinical text, such as progress notes, radiology reports, and pathology reports. We developed an NLP-based system using open-source software to process electronic clinical notes from 1995 to 2012 for women with early-stage incident breast cancers to identify whether and when recurrences were diagnosed. We developed and evaluated the system using clinical notes from 1,472 patients receiving EHR-documented care in an integrated health care system in the Pacific Northwest. A separate study provided the patient-level reference standard for recurrence status and date. The NLP-based system correctly identified 92% of recurrences and estimated diagnosis dates within 30 days for 88% of these. Specificity was 96%. The NLP-based system overlooked 5 of 65 recurrences, 4 because electronic documents were unavailable. The NLP-based system identified 5 other recurrences incorrectly classified as nonrecurrent in the reference standard. If used in similar cohorts, NLP could reduce by 90% the number of EHR charts abstracted to identify confirmed breast cancer recurrence cases at a rate comparable to traditional abstraction.

Clinical assessment and treatment of the dysfunctional larynx after radiation.

OBJECTIVE: To review the pathophysiology of early and late radiation-related tissue changes, methods to differentiate these changes from disease recurrence, and treatment of these changes in the irradiated larynx. DATA SOURCES: Peer-reviewed publications. REVIEW METHODS: PubMed database search. CONCLUSIONS/IMPLICATIONS FOR PRACTICE: Early and late radiation-related changes in the larynx manifest variably between individual patients. Severe radiation-related tissue changes in the larynx and recurrent malignancy share many clinical characteristics, and the presence of malignancy must be considered in these patients. Positron emission tomography may help select patients who need operative biopsy to rule out recurrence. In patients with a cancer-free but dysfunctional larynx, both surgical and nonsurgical treatment options, including hyperbaric oxygen, are available for attempted salvage. Further investigation is needed before hyperbaric oxygen can be considered standard-of-care treatment for these patients.

Quality of life impact of external beam radiotherapy for advanced thyroid carcinoma.

BACKGROUND: External beam radiotherapy (XRT) has an established role in the management of recurrent or advanced well-differentiated thyroid carcinoma (WDTC). The goal of this study was to investigate the impact of this additional intervention on the quality of life (QOL) compared with total thyroidectomy (TT), with or without adjuvant radioactive iodine (RAI). METHODS: A cross-sectional analysis using validated QOL instruments was performed. Patients receiving XRT between 1992 and 2008 for WDTC were identified and offered study participation. The Quality of Life Radiation Therapy Instrument and the Head and Neck Companion Module were administered retrospectively (N=13). For a comparison, patients previously treated with TT (N=11) alone as well as TT with postoperative RAI (N=11) for WDTC were also evaluated. RESULTS: Thirty-four patients were included in the analysis. The XRT group reported significant decreases in chewing, swallowing, and appetite, and significant increase in pain, compared with both the RAI group and the TT group. Significant differences were reported for questions with regard to peace of mind, feeling discouraged, saliva, taste, ability to eat regular food, and concerns for the appearance of the neck in both RAI and XRT groups compared with TT patients. Subscale analysis of head and neck specific questions demonstrated significant overall differences for both RAI and XRT groups compared with thyroidectomy alone, with no differences observed between RAI and XRT groups in a direct comparison. CONCLUSIONS: RAI therapy results in a measurable decrease in head and neck specific QOL measures compared with TT alone. The addition of XRT results in additional measurable morbidity secondary to pain and dysphagia.

Thermal characteristics of thermobrachytherapy surface applicators for treating chest wall recurrence.

The aim of this study was to investigate temperature and thermal dose distributions of thermobrachytherapy surface applicators (TBSAs) developed for concurrent or sequential high dose rate (HDR) brachytherapy and microwave hyperthermia treatment of chest wall recurrence and other superficial diseases. A steady-state thermodynamics model coupled with the fluid dynamics of a water bolus and electromagnetic radiation of the hyperthermia applicator is used to characterize the temperature distributions achievable with TBSAs in an elliptical phantom model of the human torso. Power deposited by 915 MHz conformal microwave array (CMA) applicators is used to assess the specific absorption rate (SAR) distributions of rectangular (500 cm(2)) and L-shaped (875 cm(2)) TBSAs. The SAR distribution in tissue and fluid flow distribution inside the dual-input dual-output (DIDO) water bolus are coupled to solve the steady-state temperature and thermal dose distributions of the rectangular TBSA (R-TBSA) for superficial tumor targets extending 10-15 mm beneath the skin surface. Thermal simulations are carried out for a range of bolus inlet temperature (T(b) = 38-43 degrees C), water flow rate (Q(b) = 2-4 L min(-1)) and tumor blood perfusion (omega(b) = 2-5 kg m(-3) s(-1)) to characterize their influence on thermal dosimetry. Steady-state SAR patterns of the R- and L-TBSA demonstrate the ability to produce conformal and localized power deposition inside the tumor target sparing surrounding normal tissues and nearby critical organs. Acceptably low variation in tissue surface cooling and surface temperature homogeneity was observed for the new DIDO bolus at a 2 L min(-1) water flow rate. Temperature depth profiles and thermal dose volume histograms indicate bolus inlet temperature (T(b)) to be the most influential factor on thermal dosimetry. A 42 degrees C water bolus was observed to be the optimal choice for superficial tumors extending 10-15 mm from the surface even under significant blood perfusion. Lower bolus temperature may be chosen to reduce the thermal enhancement ratio (TER) in the most sensitive skin where maximum radiation dose is delivered and to extend the thermal enhancement of radiation dose deeper. This computational study indicates that well-localized elevation of tumor target temperature to 40-44 degrees C can be accomplished by large surface-conforming TBSAs using appropriate selection of coupling bolus temperature.

Radiochemotherapy in combination with regional hyperthermia in preirradiated patients with recurrent rectal cancer.

BACKGROUND AND PURPOSE: Encouraging results of phase II studies combining chemotherapy with radiotherapy have been published. In this study, the results of a multimodal salvage therapy including radiochemotherapy (RCT) and regional hyperthermia (RHT) in preirradiated patients with recurrent rectal cancer are reported. PATIENTS AND METHODS: All patients enrolled had received previous pelvic irradiation (median dose 50.4 Gy). The median time interval between prior radiotherapy and the onset of local recurrence was 34 months. The combined treatment consisted of reirradiation with a median dose of 39.6 Gy (30.0-45.0 Gy), delivered in fractions of 1.8 Gy/day. 5-fluorouracil was given as continuous infusion 350 mg/m(2)/day five times weekly, and RHT (BSD-2000 system) was applied twice a week within 1 h after radiotherapy. The primary endpoint was local progression-free survival (LPFS); secondary endpoints were overall survival, symptom control, and toxicity. RESULTS: 24 patients (median age 59 years) with a previously irradiated locally recurrent adenocarcinoma of the rectum were enrolled. The median LPFS was 15 months (95% confidence interval 12-18 months] with a median follow-up of 27 months (16-37 months). The overall 1-year and 3-year survival rates were 87% and 30%, respectively. Pain was the main symptom in 17 patients. Release of pain was achieved in 12/17 patients (70%). No grade 3 or 4 hematologic or skin toxicity occurred. Grade 3 gastrointestinal acute toxicity was observed in 12.5% of the patients. Paratumoral thermometry revealed a homogeneous distribution of temperatures. CONCLUSION: RCT combined with RHT is an efficient salvage therapy showing high efficacy with acceptable toxicity and can be recommended as treatment option for this unfavorable group of preirradiated patients with local recurrence of rectal cancer.

Primary transpupillary thermotherapy for 18 small posterior pole uveal melanomas.

PURPOSE: To evaluate transpupillary thermotherapy (TTT) for the treatment of small uveal melanomas of the posterior pole. DESIGN: Prospective, nonrandomized interventional case series. METHODS: Eighteen patients underwent TTT for small uveal melanomas located in the posterior pole of the eyes. Tumors were between 2.5 and 4 mm in thickness. TTT was performed with a diode laser at 810 nm. Patients had between one and three TTT sessions, with an intensity adapted to the coloration of the fundus impact. Biomicroscopic examination, ultrasonographic measurements, and angiography were performed before and two months, four months, and six months after treatment, then regularly during follow-up. RESULTS: Eight of the 18 tumors regressed and 10 recurred. The one- and two-year metastasis-free survival rates calculated by the Kaplan-Meier method were, respectively, 61.11% to 44.44% (95% confidence interval). Recurrences were managed with enucleation (three patients), proton beam therapy (six), or additional thermotherapy (one). After treatment, visual acuity was maintained or improved for the eight patients with nonrecurrent tumors. Pathologic analysis of the three enucleated eyes revealed scleral invasion. CONCLUSIONS: Despite encouraging initial short-term results obtained with TTT for the management of small choroidal melanomas, the occurrence of severe complications, especially recurrences and insufficient local tumor control, should raise concern about indications for primary TTT given as isolated treatment for small melanomas of the posterior pole.

Oxygenation measurements in head and neck cancers during hyperbaric oxygenation.

BACKGROUND: Tumor hypoxia has proven prognostic impact in head and neck cancers and is associated with poor response to radiotherapy. Hyperbaric oxygenation (HBO) offers an approach to overcome hypoxia. We have performed pO2 measurements in selected patients with head and neck cancers under HBO to determine in how far changes in the oxygenation occur and whether a possible improvement of oxygenation parameters is maintained after HBO. PATIENTS AND METHODS: Seven patients (five male, two female, age 51-63 years) with squamous cell cancers of the head and neck were investigated (six primaries, one local recurrence). The median pO2 prior to HBO was determined with the Eppendorf histograph. Sites of measurement were enlarged cervical lymph nodes (n = 5), the primary tumor (n = 1) and local recurrence (n = 1). Patients then underwent HBO (100% O2 at 240 kPa for 30 minutes) and the continuous changes in the oxygenation during HBO were determined with a Licox probe. Patients had HBO for 30 minutes (n = 6) to 40 minutes (n = 1). HBO was continued because the pO2 had not reached a steady state after 30 minutes. After decompression, patients ventilated pure oxygen under normobaric conditions and the course of the pO2 was further measured over about 15 minutes. RESULTS: Prior to HBO, the median tumor pO2 in the Eppendorf histography was 8.6 +/- 5.4 mm Hg (range 3-19 mm Hg) and the pO2 measured with the Licox probe was 17.3 +/- 25.5 mm Hg (range 0-73 mm Hg). The pO2 increased significantly during HBO to 550 +/- 333 mm Hg (range 85-984 mm Hg, p = 0.018). All patients showed a marked increase irrespective of the oxygenation prior to HBO. The maximum pO2 in the tumor was reached after 10-33 minutes (mean 17 minutes). After leaving the hyperbaric chamber, the pO2 was 282 +/- 196 mm Hg. All patients maintained an elevated pO2 for further 5-25 minutes (138 +/- 128 mm Hg, range 42-334 mm Hg, p = 0.028 vs the pO2 prior to HBO). CONCLUSIONS: Hyperbaric oxygenation resulted in a significant increase in the tumor oxygenation in all seven investigated patients. A significant increase at the point of measurement could be maintained for several minutes after decompression and after leaving the hyperbaric chamber.

[1H-MR Spectroscopy of brain tumors in the course of radiation therapy: Use of fast spectroscopic imaging and single-voxel spectroscopy for diagnosing recurrence]. / 1H-MR-Spektroskopie von Hirntumoren im Verlauf der Strahlentherapie: Anwendung von schneller spektroskopischer Bildgebung und Einzelvolumen-MRS in der Rezidivdiagnostik.

PURPOSE: To improve differential diagnosis of residual or recurrent tumor vs. tissue necrosis in the course of radiation therapy of neurosurgically-treated brain tumors by application of fast (1)H-MR spectroscopic imaging in combination with single-voxel spectroscopy (SVS). METHODS: 54 patients after with malignant brain tumor (44 cases of glioblastoma, 10 other high-grade gliomas) were examined post-surgically in a total of 140 proton MRS examinations in the course of radiotherapy and in follow-up controls. Fast SI acquisition was performed as single-slice or double-slice TSI sequence with 32 x 32 phase encodings within 11 or 15 minutes, respectively. SVS with TR/TE 2000/272 ms yielded relative metabolite ratios, and in 15 patients the time courses of the absolute concentrations of brain metabolites were also determined. RESULTS: In the group of 44 patients that could be tracked by MRS until therapy completion, TSI localized in 23 patients a persistent or newly arisen distinct choline accumulation indicating residual or recurrent tumor after radiation therapy. In all these cases MRS diagnosis was confirmed histologically or by short-term follow-up. However, in 6 of 15 patients showing a normal choline pattern in the TSI acquisition, tumor recurrence appeared within three months. SVS provided early recognition of recurrent tumor when detecting characteristic alterations of metabolite concentrations oin therapy follow-up. CONCLUSION: TSI and SVS represent complementary MRS techniques and are able to diagnose tumor recurrence early and unambiguously in cases where focal choline accumulation is detected.

Serial proton MR spectroscopic imaging of recurrent malignant gliomas after gamma knife radiosurgery.

BACKGROUND AND PURPOSE: The diagnosis of brain tumors after high-dose radiation therapy is frequently limited by the lack of metabolic discrimination available with conventional imaging methods. The purpose of this study was to use proton MR spectroscopy to investigate serial changes in recurrent malignant gliomas after gamma knife radiosurgery to characterize tissue response to high-dose radiation. METHODS: Eighteen patients with recurrent gliomas were studied with MR imaging and 3D proton MR spectroscopic imaging at the time of radiosurgery and at regular time points thereafter. Choline (Cho) and N-acetyl aspartate levels were calculated on a voxel-by-voxel basis and compared with levels found in normal tissue and with levels observed at previous time points. The results of the spectral analysis were then compared with the radiologic findings. Statistical comparisons were precluded by the small sample sizes involved. RESULTS: Response within the gamma knife target was observed as a reduction of Cho levels and an increase in lactate/lipid levels, typically within 6 months of treatment. Increases in Cho correlated with poor radiologic response and suggested tumor recurrence, confirmed histologically in six cases. The development of a spectral abnormality preceded a coincident increase in contrast enhancement by 1 to 2 months in nine cases. CONCLUSION: Proton MR spectroscopic imaging provided diagnostic and monitoring information before and after radiosurgery. Evaluation of metabolic changes with proton MR spectroscopy and structural changes with MR imaging improved tissue discrimination and provided correlation with histologic findings.