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M Molls

Publications and source records attributed to M Molls.

At least 73 records · Page 4Linked to original sources
PubMed1997

Fluorine-18-FDG PET and iodine-123-IMT SPECT in the evaluation of brain tumors.

UNLABELLED: The high glucose utilization of normal gray matter limits the detection of brain tumor tissue by PET using 18F-fluorodeoxyglucose (FDG). The aim of this study was to evaluate whether the examination of amino acid transport with the SPECT tracer 123l-alpha-methyl-L-tyrosine (IMT) allows better identification of tumor tissue than FDG-PET. METHODS: Nineteen patients (16 with gliomas, 3 with nontumorous lesions) were included in the study. Two independent observers classified PET and SPECT images as positive or negative for tumor tissue and defined the extent of tumor with regions of interest. Tracer uptake of FDG and IMT was quantified by calculating the tumor uptake relative to contralateral gray and white matter. RESULTS: SPECT studies were interpreted concordantly in 18 patients (kappa = 0.77) and all tumors were identified by both observers. PET studies were interpreted discordantly in 4 patients (kappa = 0.52) and only 10 tumors were identified by both observers, interobserver variability in definition of tumor extent was significantly lower in the IMT-SPECT than in the FDG-PET studies (p = 0.03). Mean tumor uptake relative to gray and white matter was 1.93 +/- 0.42 and 2.25 +/- 0.46 for IMT and 0.93 +/- 0.32 and 1.61 +/- 0.52 for FDG. All tumor uptake ratios were significantly (p < 0.01) higher for IMT than FDG, even when only glioblastomas were analyzed. No significant correlation was observed between the various uptake ratios of FDG and IMT. CONCLUSION: Despite the lower resolution and lower sensitivity of SPECT compared with PET, IMT-SPECT was clearly superior to FDG-PET in the detection and delineation of tumor tissue.

Astrocytoma↗
PubMed1996

Locally advanced rectal cancer: resection and intraoperative radiotherapy using the flab method combined with preoperative or postoperative radiochemotherapy.

PURPOSE: Surgery often fails to achieve local control in advanced rectal cancer. Additional measures are necessary to prevent local recurrence. The aim of this study was to evaluate intraoperative radiation therapy (IORT) (flab technique) combined with preoperative or postoperative radiochemotherapy. PATIENTS/METHODS: IORT is performed using a flexible flab containing hollow plastic tubes that are connected to a multichannel afterloading device with a 370 Gbq-192-Ir source. Patients receive an intraoperative dose of 15 Gy. Target volumes were measured in a cadaver experiment. From 1989 to 1993, 38 patients were included in this study. Nineteen patients were staged as T3 tumors by preoperative endosonography (Group I) and 19 as T4 tumors (Group II). Patients in Group I underwent resection (abdominoperineal resection (APR), 16; anterior resection, 3) and IORT, followed by postoperative radiochemotherapy (50 Gy/5-fluorouracil), whereas patients in Group II received preoperative radiochemotherapy (40 Gy/5-fluorouracil) followed by resection (APR, 18; anterior resection, 1) and IORT. Mean follow-up was 25.5 months. RESULTS: Operative radicality in Group I was RO (13), R1 (3), and R2 (3), and in Group II it was RO (14), R1 (3), R2 (2). R2 resections were attributable to preoperative undetected distant metastases. Perioperative mortality was 0 percent in Group I and 10.5 percent (n = 2) in Group II. Postoperative morbidity was 53 percent (n = 10) in Group I and 84 percent (n = 16) in Group II with delayed sacral wound healing being the predominant problem. Stenosis of the ureter occurred in two patients (Group II). Late or persistent therapy-related complications were seen in two patients in Group I and in six patients in Group II. Local recurrence developed in three patients in Group I (15.8 percent) and in two patients in Group II (10.5 percent). Survival data do not reach statistical significance between the two groups because of small numbers but show a favorable trend for the preoperative radiochemotherapy group. When compared with a matched historical control group of patients receiving resection only, adjuvant/neoadjuvant radiotherapy with resection/IORT improves survival significantly. CONCLUSION: The flab method is a simple but especially practical technique for IORT in the pelvis. Adjuvant/neoadjuvant therapy combined with resection/IORT is associated with high morbidity but acceptable mortality. Preliminary survival data are encouraging and call for a controlled prospective randomized trial.

Antimetabolites, Antineoplastic↗
PubMed1996

Oxygen tension in mouse mammary carcinomas and osteosarcomas after irradiation with reactor fission neutrons.

Investigations were made on intratumoral oxygen tension after irradiations with reactor fission neutrons using the Eppendorf-pO2-Histograph. Isotransplanted AT17-mammary carcinomas on C3H-mice and osteosarcomas OTS-64 on Balb c-mice received 2 or 6 Gy neutrons single dose. Before and at certain points of time after treatment the pO2-values were evaluated. Some tumors with initially low median pO2-values showed a short-lasting increase between 2 and 24 hours after irradiation. In the tumors with relatively high median pO2-values before irradiation the pO2 decreased to hypoxic range. A third group of tumors showed no significant changes after irradiation. None of the tumors stopped growth during the observation period.

Adenocarcinoma↗
PubMed1996

[Ultrasound volumetry of cervical lymph nodes during radiotherapy as a method of therapy monitoring].

PURPOSE: Volumetric changes of cervical lymph nodes during radiotherapy (RT) should be evaluated with B-mode sonography. It was our intention to test whether ultrasound could be used for therapeutic monitoring. METHOD: 30 lymph nodes of 20 patients were measured. All patients underwent radiotherapy of the cervical region. All lymph nodes were checked at first one day before RT, and then once a week. RESULTS: Concerning the volume change, examined lymph nodes showed great differences. Pretreatment volume ranged from 0.26 to 96.5 cm3, median 4.9. Time volume 50%, i.e. time until volume had decreased by 50%, was reached after 21 (+/-11) days. Mean volume reduction was 1.3 (+/-1.6)% each day. Big lymph nodes needed more time until time volume 50%. Time volume 50% itself correlated positively with the therapeutic outcome. Sonographic lymph node volumetry was useful in 85% of all the patients. CONCLUSIONS: Sonographic lymph node volumetry is a simple and practical method. It can be used easily in clinical routine. Radiotherapist can often gain therapeutically relevant information. We describe the use of sonography for therapy monitoring during RT. This has so far been an unknown potential of the method. However, further evaluation is required.

Adult↗
PubMed1996

[Tissue oxygen partial pressure in human head-neck carcinomas during primary radio-chemotherapy].

BACKGROUND: Experimental data have shown that hypoxic areas in tumors can increase their malignant potential and reduce their sensitivity to chemotherapy and radiation treatment. Until now, the only incomplete data on the oxygenation of human tumors during therapy have been available. METHODS: The distribution of partial pressure of oxygen in malignant head and neck processes was measured in four patients with lymph-node metastases by means of invasive computerized histography (system manufactured by Eppendorf). All patients received primary radiation treatment and chemotherapy with a two-week respite after 30 Gy and the first cycle of chemotherapy. The total dose consisted of 70 Gy in the tumor and two cycles of chemotherapy. Oxygen measurements were taken before the onset of treatment, before and after the respite, and after completion of treatment. RESULTS: In three of the four patients, we measured prominent hypoxic areas in the cancers with PO2 values less than 5 mmHg. The average value was between 12 and 46 mmHg. We were impressed by the observation that oxygenation appeared to improve in every cancer during the respite. Only the patient who showed good initial oxygenation without any measurable hypoxic fraction suffered a complete recurrence six weeks after the completion of therapy. CONCLUSIONS: Prominent areas of hypoxic tissue are present in human head and neck cancers. Radiation treatment and chemotherapy can alter the oxygenation. Further studies are required to investigate the significance of the oxygenation of human head and neck cancers and the changes occurring in it during different types of therapy in order to assess its clinical impact.

Adult↗
PubMed1996

Combined preoperative chemotherapy and radiotherapy in patients with locally advanced esophageal cancer. Interim analysis of a phase II trial.

PURPOSE: The prognosis of patients with locally advanced esophageal cancer (LAEC) remains poor when treated with local modalities. An intensive preoperative program with chemoradiotherapy was used to evaluate the curative resection rate, pathologic response, and survival of patients with LAEC. PATIENTS AND METHODS: Ninety patients with LAEC were treated preoperatively with chemotherapy (three courses of fluorouracil, leucovorin, etoposide, and cisplatin [FLEP]) followed by concurrent chemoradiotherapy (one course of cisplatin plus etoposide in combination with 40 Gy of radiation). Transthoracic esophagectomy was performed 4 weeks after the end of radiation. RESULTS: Seventy-two patients were included in this evaluation. Forty-four (61%) underwent a complete tumor resection, and 16 (22%) had no tumor in the resected specimen (pathologic complete response [PCR]). The operative mortality rate was 15%. At a median follow-up time of 22 months (range, 12 to 41), the median survival duration of all 72 patients was 17 months (range, 1 to 41+). The calculated survival rates at 3 years were 33%, 42%, and 68% for all patients, patients after complete resection, and patients with PCR, respectively. CONCLUSION: This combined treatment modality is active in LAEC, with a PCR in 33% of the patients undergoing surgery. The results appear improved compared with those reported with surgery alone, by approximately doubling the 3-year survival rate. The high efficacy of preoperative chemoradiation warrants evaluation of the role of surgery in LAEC.

Adenocarcinoma↗
PubMed1996

[Abdominal irradiation in seminomas: improvement in its planning with MRT].

BACKGROUND: Standard therapy for early stages of seminomas is the irradiation of the para-aortal and paracaval lymphatic vessels. PATIENTS AND METHOD: Prior to radiotherapy coronal T1-weighted MRI of the abdomen was performed including imaging of target volume and critical organs. The position and course of the large abdominal vessels are projected on simulator radiographs of the abdomen. The target volume is enclosed by blocks, which are individual formed with a 2 cm margin along the vessels. RESULTS: An irregular course of the vessels in 34% of the patients resulted in modifications of the radiation field compared with standard fields. Thus more than 10% of the volume of the left kidney could be taken out of field in 25% of the patients. Simultaneously fields were enlarged on contralateral side to make sure that the paracaval lymphatic drainage was enclosed. CONCLUSIONS: MRI-assisted planning of radiotherapy allows a more individualized treatment by visualization of the big abdominal vessels guiding the para-aortal lymphatics. The target volume is surely enclosed, healthy organs are optimal spared.

Abdomen↗
PubMed1995

Hyperthermia--its actual role in radiation oncology. Part III: Clinical rationale and results in deep seated tumors.

PURPOSE: Combined hyperthermia and radiation therapy has been reported to yield higher complete and durable responses than radiotherapy alone in superficial tumors. In deep seated tumors the effect of the combined treatment is still under research. METHODS: The literature and own clinical data are reviewed with regard to biological and physical fundamentals and clinical results. RESULTS: Clinical phase I to II studies have applied regional hyperthermia in the abdomen, the pelvic region and the extremities. Usually primary advanced, persistent or local recurrent and metastatic tumors were selected for treatment either due to poor response to conventional therapy or for effective palliation. The clinical data are presented concerning the following topics: invasive thermometry, temperature parameter in tumor and normal tissue, toxicity, tumor response, treatment planning, clinical trials and prognostic factors. Clinical results of thermoradiotherapy for advanced or recurrent rectal cancer, cervical cancer and soft tissue sarcomas are reviewed in detail. In addition, the prognostic relevance of temperature parameters and physiological conditions such as global tumor perfusion are discussed. CONCLUSION: Clinical issues of optimization of regional thermoradiotherapy are: improvement of hyperthermia technique, analysis of biological effects and mechanisms involved in temperature elevation, selection of appropriate study concepts for specific tumor sites. Part I has covered biological and technical fundamentals of clinical hyperthermia and has been published in Strahlenther. Onkol. 168 (1992), 183-190. Part II has covered clinical fundamentals and results in superficial tumors of clinical hyperthermia and has been published in Strahlenther.

Algorithms↗
PubMed1995

[The flab method of intraoperative radiotherapy].

PURPOSE: Improvement of the relapse rate by locally increasing the tumor dose. METHODS: To increase the dose in the tumor bed a method for intraoperative radiation therapy has been developed. The radiation is applied using a high-dose-rate afterloading system. Flexible plastic flabs are used as applicators. Each flab contains tubes for the alterloading source. The size of the applicator is chosen to correspond to the size of the target volume. In the dosage system we use the dwell times at all source positions are equal. The dwell time has been precalculated to give the reference dose at the reference position which is located at the surface of the flab in the center of the target volume. RESULTS: The dose distributions around the flab have been calculated as a function of the thickness of the flab. If the source is not placed on a regular grid within the applicator due to a non ideal positioning of the tubes within the applicator, the dose distribution is not altered too much, if the positioning error is not larger than +/- 2 mm. The influence of a curvature of the flab has been evaluated and methods to decrease the dose at critical organs are discussed. CONCLUSION: The flab methods for IORT is safe and easy and has been demonstrated for more than 150 cases. This method allows the increase in tumor dose even in regions which are not easily treated by electron IORT due to the rigid electron applicators. Because of the rapid dose fall off, the flab method can only be used for flat target volumes like the tumor bed.

Humans↗
PubMed1995

Hyperthermia--its actual role in radiation oncology. Part IV: Thermo-radiotherapy for malignant brain tumors.

BACKGROUND: High-grade malignant gliomas have a dismal prognosis. Only achievement of long-term local control improves overall survival. Conventional treatments have not been successful, but thermoradiotherapy appears to be a promising new approach to this disease. PATIENTS AND METHODS: The review addresses the various HT techniques applied for brain heating, the biological rationale and experimental studies supporting the use of heat in addition to radiotherapy for brain tumors. Normal brain damage exposed to heat is critically evaluated. Clinical trials implementing HT for tumors of the brain accumulating more than 400 patients are discussed. RESULTS: HT is a feasible and effective approach to brain tumors. Important selection criteria are tumor size (< 6 cm) and location (supratentorial, peripheral). Acute treatment toxicity is relatively low and long-term side effects are similar to those observed for RT alone. In some studies a high response rate and improvement of survival was achieved. Tumor control and survival depend on histology (anaplastic astrocytoma vs. glioblastoma multiforme), extent of surgery (complete vs. incomplete), tumor status (primary vs. recurrent), age and performance status. Satisfactory heating also correlates significantly with favourable treatment outcome. CONCLUSIONS: The encouraging results of clinical trials may be biased by favourable tumor and patient selection. Randomized clinical trials comparing RT alone versus combined RT-HT for advanced and recurrent brain tumors are justified. Part I has covered biological and technical fundamentals of clinical hyperthermia and has been published in Strahlenther. Onkol. 168 (1992), 183-190. Part II has covered clinical fundamentals and results in superficial tumors of clinical hyperthermia and has been published in Strahlenther. Onkol. 169 (1993), 633-654. Part III has covered clinical rationale and results in deep seated tumors and has been published in Strahlenther. Onkol. 171 (1995), 251-264.

Animals↗
PubMed1994

Oxygenation of locally advanced recurrent rectal cancer, soft tissue sarcoma and breast cancer.

Oxygen tension distributions (pO2) were measured in 20 patients with recurrent soft tissue sarcoma (n = 8), recurrent breast cancer (n = 9) and recurrent rectal cancer (n = 3) using computerized pO2 histography. A total of 35 measurements could be performed pretherapeutically. In 8 measurements there exist some problems with regard to clinical relevant bleeding or uncertainties of the tumor/normal tissue boundary. In general, there is a marked tumor-to-tumor variability even for tumors of the same histology. 5 of 8 soft tissue sarcomas, 1 of 3 recurrent rectal cancers, 4 of 9 breast cancers exhibited pO2 values between zero and 2.5 mmHg, i.e. tissue areas with less than half-maximum radiosensitivity.

Aged↗
PubMed1994

Changes in oxygenation patterns of locally advanced recurrent tumors under thermoradiotherapy.

Oxygen tension distributions (pO2) were measured in 10 patients with recurrent soft tissue sarcoma (n = 4), recurrent rectal cancer (n = 2), recurrent breast cancer (n = 3) and recurrent neck nodes (n = 1) using computerized pO2 histography. Measurements were performed pretherapeutically and 24 hours after the first cytotoxic hyperthermic treatment. In one patient an increase of the mean pO2 value was evident after hyperthermia. The other 9 patients showed a significant decrease in the mean pO2 values after hyperthermia. Pooled pO2 distributions of measurements before and after hyperthermia differ statistically significant (p < 0.01). The median pO2 from 1248 measurements before hyperthermia is 18.9 mmHg, whereas the median pO2 from 1263 measurements after hyperthermia is 9.4 mmHg.

Aged↗
PubMed1994

Perioperative radiotherapy +/- chemotherapy in rectal cancer.

Locoregional failure which occurs in 25%-50% of patients with rectal cancer undergoing potentially curative surgery, can be significantly reduced by either postoperative adjuvant irradiation and also by preoperative radiotherapy. In view of the possible local side effects/complications, optimal irradiation techniques including accelerator and 3-4 field techniques are mandatory. Combined treatment consisting of radiotherapy plus chemotherapy appears to be more efficient than pelvic irradiation alone. It seems that reductions in the rate of pelvic and extrapelvic tumor recurrences which are not dramatic but of clinical significance are followed by an improved survival. The 1990 Consensus conference of the National Institute of Health recommended combined postoperative radiotherapy and chemotherapy for patients with T3N0, T4N0 and any TN1-3 rectal cancer. For future trials, the main goal has to be optimization of radiotherapy plus chemotherapy in the perioperative treatment of rectal cancer. The most important unanswered question is whether the highest therapeutic ratio is obtained by pre- or postoperative treatment.

Antineoplastic Combined Chemotherapy Protocols↗