Subject(s)
Melanoma/therapy , Skin Neoplasms/therapy , Combined Modality Therapy , Disease Progression , Fatal Outcome , Female , Forehead , Humans , Lung Neoplasms/secondary , Lung Neoplasms/therapy , Melanoma/pathology , Melanoma/secondary , Middle Aged , Neoplasm Recurrence, Local , Remission Induction , Skin Neoplasms/pathology , Time FactorsABSTRACT
In 37 brain, head and neck tumors, sagittal and coronal MR-images were superimposed on lateral and AP simulator radiographs for target definition using a subtrascope. The accurate, reproducible and efficient integration of sagittal and coronal images led to individualized delineation of target and normal tissue on simulator radiographs.
Subject(s)
Brain Neoplasms/radiotherapy , Head and Neck Neoplasms/radiotherapy , Magnetic Resonance Imaging , Radiotherapy Planning, Computer-Assisted , Dose-Response Relationship, Radiation , Humans , Radiation Protection , Radiotherapy DosageABSTRACT
In the treatment of adenoid cystic carcinomas, certain situations such as inoperable tumors, macroscopic tumor residues following surgery and recurrences occurring with the previous therapeutic strategies (surgery and/or photon radiotherapy) are afflicted with frequent local recurrences. In these situations the use of radiotherapy with fast neutrons (densely ionizing radiation with high energy transfer) results in absence of recurrences in approx. 70% of the cases, according to data in the literature. The advantage of using neutrons lies in their greater biological effect on slowly growing tumors. In the Hospital for Radiotherapy of the Münster University neutron therapy has been applied since 1986 for these indications using a DT neutron generator (14 MeV). Based on the results obtained in the treatment of 8 patients and a review of the literature, indications for, treatment planning and implementing of neutron therapy is illustrated. Particular consideration is given to CT and MRT. Neutron therapy offers an alternative to previously existing treatment methods for locally advanced adenoid cystic carcinomas or highly differentiated malignomas of the salivary glands. Its effectiveness should be verified by studies involving larger numbers of patients and longer observation periods.
Subject(s)
Carcinoma, Adenoid Cystic/radiotherapy , Head and Neck Neoplasms/radiotherapy , Neoplasm Recurrence, Local , Salivary Gland Neoplasms/radiotherapy , Adult , Aged , Fast Neutrons/therapeutic use , Female , Humans , Male , Middle Aged , Neoplasm Metastasis , Radiotherapy, High-Energy/methodsABSTRACT
In adenoidcystic carcinoma macroscopic residual disease after surgery, inoperable and recurrent tumors are characterized by relapse rates up to 70% if treated according to conventional treatment strategies including photon radiotherapy. By neutron therapy a tumor control rate of 70% has been reported. At the d,T-generator (14 MeV) in Münster nine patients with adenoidcystic carcinoma of the salivary glands in locally advanced stage have been treated since 1/86. A combined modality schedule (30 Gy photon/5 to 10 Gy neutrons) used in the beginning has been replaced by a definitive neutron therapy (15 Gy) with single fractions of 1.0 to 1.3 Gy in five to six weeks. Treatment planning included CT/MRI as well as computer assisted dose calculations based on a specific software for neutron therapy. The volume reduction by neutron radiotherapy was 82% for advanced disease. Continuous remission was achieved in seven of nine patients in a short follow-up period of medium 15 months (from six to 28 months). The two recurrences occurred at the field edge. Based on this preliminary experience and on a survey of the literature the main issues for neutron therapy in salivary glands tumors in particular adenoidcystic carcinomas are discussed: histology, stage, tumor size, location, surgery, treatment planning and delivery, dose, and side effects. A long term evaluation of neutron therapy within a controlled clinical multicenter trial is proposed.
Subject(s)
Carcinoma, Adenoid Cystic/radiotherapy , Neutrons/therapeutic use , Salivary Gland Neoplasms/radiotherapy , Adult , Aged , Aged, 80 and over , Carcinoma, Adenoid Cystic/diagnosis , Carcinoma, Adenoid Cystic/mortality , Female , Follow-Up Studies , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neoplasm Metastasis , Neoplasm Recurrence, Local , Radiation , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted , Salivary Gland Neoplasms/diagnosis , Salivary Gland Neoplasms/mortality , Time Factors , Tomography, X-Ray ComputedABSTRACT
Well differentiated soft tissue sarcomas may benefit from fast neutron radiotherapy, in particular inoperable and recurrent tumors and tumors with residual disease after non-radical surgery. Treatment planning in a multidisciplinary pretherapeutic approach has to be based on tumor size and site and histopathology. Target volume definitions for potential microscopic spread and for the high risk region of local recurrence have to consider the preoperative tumor localization (imaging), the biological behavior and the extent of surgery. GI/II, T1-3 tumors after intralesional or marginal resection are indications for neutron therapy. Treatment planning and delivery has to take into account the narrow therapeutic range of fast neutrons and include individual immobilization devices, manufacturing of bolus and CT based computed dose calculations. Neutron radiotherapy techniques at the d, T generator are comparable to photon techniques except individual beam shaping, field size and portal verification. Total dose is 16 Gy neutrons in the high risk region and 12 to 13 Gy in the region of potential microscopic spread.