Jimmy O. Fenn

Pathologic changes in the lung following single and multi-fraction irradiation

Abstract The limiting factor in the treatment of malignant disease with irradiation is the tolerance of normal tissue irradiated. In the present study the right lungs of rats were exposed to single doses of 2000 rad of X-radiation, to 10 × 200 rad, or to 5 × 400 rad. Animals from each group were sacrificed monthly for 6 months post exposure. Sections of lung were examined by light microscopy (LM) and by scanning or transmission electron microscopy (SEM and TEM). A focal exudative lesion was seen at 2 months after the single dose; it progressed to a proliferative and then reparative, fibrotic lesion by 6 months. Changes in epithelial lung components, particularly the presence of Type II pneumocytes, were found with both LM and TM. Vascular changes were less pronounced. A striking finding was the presence of mast cells in the alveolar walls. Neither of the mufti-fraction schedules produced any of these changes, except hyperplasia of Type II cells following 5 × 400 rad. The possible implication of Type II and mast cells in radiation pneumonitis and fibrosis is discussed.

Intraperitoneal P-32 after negative second-look laparotomy in ovarian carcinoma

Thirty‐one patients underwent a negative second‐look laparotomy between 1976 and 1986. Fourteen patients received intraperitoneal chromic phosphate (P‐32) after a negative second‐look laparotomy. There has been no local recurrence (zero of 14) and no deaths attributable to recurrent disease. Local control and disease‐free survival are 100%, with a minimum follow‐up of 2 years and a mean follow‐up of 4 years. Seventeen patients received no further therapy because of patient refusal, poor diffusion, or other contraindications to P‐32 installation. Four of 17 patients undergoing negative second‐look procedures without the addition of P‐32 have subsequently recurred. This difference is highly suggestive (P =.076). There have been no major complications with the addition of P‐32. The use of intraperitoneal P‐32 after negative second‐look laparotomies on ovarian carcinoma is well tolerated and effective in preventing recurrence.

Megavoltage therapy in patients with aneurysmal bone cysts.

Three adolescent patients with similar destructive lesions involving the pelvis were found to have unresectable aneurysmal bone cysts. All 3 patients appear to have permanent control and good function from 2 to 7 years after megavoltage irradiation with 4,000 rads. No complications or late sequelae have occurred, and follow-up radiographs demonstrate reconstitution and calcification of the affected bone. A slightly lower dose may be just as effective in controlling such lesions.

Adenocarcinoma of the endometrium: Role of preoperative radiation in stage I disease

Abstract A prospective study was reported evaluating the effectiveness of preoperative radiation focused on the vaginal apex followed immediately by abdominal hysterectomy and bilateral salpingo-oophorectomy as a means of therapy for Stage I adenocarcinoma of the endometrium. Eighty-three consecutive patients over a 53/4-yr span of time were studied. This technique resulted in a predicted 5-yr survival of 91.8%. Complications were low and patient acceptance excellent. The precise dosages and schedules were discussed in detail.

Treatment planning optimization for multiple arcs stereotactic radiosurgery using a linear accelerator.

PURPOSE Multiarc stereotactic radiosurgery is a technique used to irradiate an intracranial tumor with minimal damage to the surrounding normal tissue. The purpose of this paper is to present a method for and the results from optimizing three dimensional (3D) treatment dose for multiarc stereotactic radiosurgery. METHODS AND MATERIALS The normal procedure for a physician-physicist team designing a treatment plan for multiarc stereotactic radiosurgery is the trial-and-error approach of changing the collimator size and the isocenter of radiation by viewing the isodose curves on a two dimensional (2D) computed tomography (CT) or magnetic resonance imaging (MRI) image plane. Not only is this time consuming, but the resulting treatment plan is not optimal in most, if not all, cases. One reason for such nonconformal isodose curves is that the same collimator size is used for all arcs. However, it is very difficult to determine manually the different collimator sizes for different arcs. A derivative free optimization method is used to optimize the collimator size for each arc, as well as the 3D coordinates of the isocenter(s). RESULTS One spherical and two ellipsoidal artificial tumors, and one actual tumor, were used to show the utilities of the optimization process. The 90% isodose curves resulting from optimization conform very well with the tumor; whereas the 90% isodose curves from the conventional method either do not envelop the entire tumor when the collimator size is too small, or a large volume of normal tissue is also irradiated by the 90% dose when the next larger collimator size is used. CONCLUSIONS When the collimator size for each arc and the location of the isocenters(s) are optimized in a multiarc stereotactic surgery treatment plan, the 90% isodose curve conforms to the tumor much better than when the same collimator size is used for all arcs.

Original contributionPathologic changes in the lung following single and multi-fraction irradiation☆

Abstract The limiting factor in the treatment of malignant disease with irradiation is the tolerance of normal tissue irradiated. In the present study the right lungs of rats were exposed to single doses of 2000 rad of X-radiation, to 10 × 200 rad, or to 5 × 400 rad. Animals from each group were sacrificed monthly for 6 months post exposure. Sections of lung were examined by light microscopy (LM) and by scanning or transmission electron microscopy (SEM and TEM). A focal exudative lesion was seen at 2 months after the single dose; it progressed to a proliferative and then reparative, fibrotic lesion by 6 months. Changes in epithelial lung components, particularly the presence of Type II pneumocytes, were found with both LM and TM. Vascular changes were less pronounced. A striking finding was the presence of mast cells in the alveolar walls. Neither of the mufti-fraction schedules produced any of these changes, except hyperplasia of Type II cells following 5 × 400 rad. The possible implication of Type II and mast cells in radiation pneumonitis and fibrosis is discussed.

Pathologic changes in the lung following single and multi-fraction irradiation. [Rats, x radiation]

Abstract The limiting factor in the treatment of malignant disease with irradiation is the tolerance of normal tissue irradiated. In the present study the right lungs of rats were exposed to single doses of 2000 rad of X-radiation, to 10 × 200 rad, or to 5 × 400 rad. Animals from each group were sacrificed monthly for 6 months post exposure. Sections of lung were examined by light microscopy (LM) and by scanning or transmission electron microscopy (SEM and TEM). A focal exudative lesion was seen at 2 months after the single dose; it progressed to a proliferative and then reparative, fibrotic lesion by 6 months. Changes in epithelial lung components, particularly the presence of Type II pneumocytes, were found with both LM and TM. Vascular changes were less pronounced. A striking finding was the presence of mast cells in the alveolar walls. Neither of the mufti-fraction schedules produced any of these changes, except hyperplasia of Type II cells following 5 × 400 rad. The possible implication of Type II and mast cells in radiation pneumonitis and fibrosis is discussed.

Physical considerations in using thermal techniques for the delineation of radiation damage in skin

In irradiated skin, damage occurs not only to the skin but also to the vasculature transporting blood to and from the skin. Since heat is transported from the body core to the periphery of the body by the blood as well as by direct transmission, a decreased rate of heat transfer to the skin should occur in persons receiving a significant dose of radiation. The physical considerations of this change in the vasculature, with the skin at thermal equilibrium and non-equilibrium conditions, were explored and the hypothesis tested. A temperature mapping of the irradiated and non-irradiated skin of patients previously treated for carcinoma of the cervix was performed using a cholesterol ester liquid crystal device (RhochromeR). The results show that, in only one patient, was there sufficient damage to give a thermal difference between irradiated and non-irradiated skin at equilibrium conditions. In other patients, however, a thermal difference was seen following a thermal shock. An analysis of the physical considerations was discussed, along with the detailed results of the procedure.