Inoperable endobronchial obstructing lung cancer treated with combined endobronchial and external beam irradiation: a dosimetric analysis.

PURPOSE: This study is a dosimetric review of our experience incorporating both external beam radiotherapy and endobronchial brachytherapy in the treatment of inoperable endobronchial obstructing lung cancer. METHODS AND MATERIALS: Sixty-five patients with symptomatic inoperable endobronchial obstructing lung cancer received combined external beam radiotherapy and temporary endobronchial iridium (Ir)-192 implants between February 1987 and May 1991. External beam irradiation doses ranged from 55 to 66 Gy. Patients were given 2 to 4 temporary Ir-192 endobronchial implants at the site of endobronchial obstruction. Individual implant doses ranged from 2.7 to 10 Gy. Total implant doses ranged from 6 to 35 Gy. Total treatment doses ranged from 61 to 96.6 Gy. RESULTS: Sixty-three percent of patients had a complete local endobronchial response to treatment and 23% had a partial response. Forty-seven percent of patients receiving a total dose of less than 70 Gy experienced a complete local endobronchial response to treatment while 83% of patients receiving a total dose of 85 Gy or greater experienced a complete local endobronchial response to treatment. Sixty-six percent experienced an improvement in their performance status using an Eastern Cooperative Oncology Group performance scale. Survival from the end of treatment was 38% at 1 year and 23% at 2 years, with the median survival at 8 months. Complications occurred in 9/65 (14%) of patients; 0% in patients receiving a total dose of less than 70 Gy, 10% in patients receiving a total dose of 70 to 84.99 Gy, and 24% of patients receiving a total dose of 85 Gy or higher. CONCLUSION: The data from this study again confirms the feasibility of this form of treatment for inoperable endobronchial obstructing lung cancer. In addition, there appears to be a dose response for both local response and complications.

Inoperable endobronchial obstructing lung carcinoma treated with combined endobronchial and external beam irradiation.

Thirty patients with symptomatic inoperable endobronchial obstructing lung cancer received combined external beam radiotherapy and temporary endobronchial iridium Ir 192 implants. External beam irradiation doses ranged from 5700 to 6600 cGy. Patients were given two to four temporary iridium Ir 192 implants for endobronchial radiotherapy. Individual implant doses ranged from 500 to 1500 cGy. Total implant doses ranged from 1125 to 3000 cGy. Total treatment doses ranged from 7080 cGy to 10,000 cGy. Seventy-seven percent of patients had a complete local endobronchial response to treatment, and 13% had a partial response. Ninety percent of patients experienced an improvement in their performance status using an Eastern Cooperative Oncology Group (ECOG) scale. Survival from the end of treatment was 39% at 1 year and 21% at 2 years, with the median survival at 10 months. The data from this study indicate that this form of treatment of inoperable endobronchial obstructing lung cancer is feasible and leads to a high percentage of local tumor response, improvement in patient performance status, and possibly improved survival.

Primary angiosarcoma of the brain.

We have described a 32-year-old black woman who had a primary angiosarcoma of the right occipital lobe. All three previously reported cases have been fatal within 1 year. Our patient is doing well more than 3 1/2 years after surgery.

Adjustable field shaping for external-beam radiation therapy.

A new, simple method for adjustable field shaping for external-beam radiation therapy is described. The system employs shielding blocks attached to specially designed flanges and blocking tray. The system allows a wide latitude of placement of the blocks on the tray. The blocking system is cost-effective and allows rapid setup of treatment fields. It also allows daily blocking adjustment if required and has been shown to produce high-quality reproducible fields in clinical use.

Radiation protection considerations for endocavitary X ray units.

Application of a contact X ray therapy unit for endocavitary irradiation of selected rectal carcinomas is gaining acceptance as a treatment of choice. The patient is placed on a proctoscopic table in the surgical suite and the anus is anesthetized and dilated to allow insertion of a 3 cm diameter proctoscope designed to admit the X ray tube. The measured half-value layer for 50 kVp X rays filtered by 1.0 mm of aluminum was determined to be 0.65 mm of aluminium. The dose rate at the end of the 4.0 cm source-skin-distance (SSD) cone was measured to be on the order of 1000 rad/minute. Radiation surveys performed for several treatment geometries indicate that exposure rate levels in the environs immediately around the patient can be quite high. Radiation measurements were made for the following locations: where the radiotherapist stands holding the X ray tube; at the side of the patient where the technologist or any supporting personnel might stand; and at the patient's posterior surface in the direction where the anesthesiologist might stand. Radiation levels ranged from 0.001 to 1.0 roentgen (R) per hour and depend primarily on the depth and angle of the X ray tube inserted into the rectum.

Palliative radiation treatment of cutaneous mycosis fungoides--a dose response.

Between 1966 and 1981, 20 patients (191 lesions) underwent palliative radiation therapy for control of biopsy-proven cutaneous mycosis fungoides. Six patients (47 lesions) and an additional 34 lesions from the remaining 14 patients with complete response to treatment were excluded from the study because of follow-up of less than one year. Included in the remaining 110 lesions were all recurrences and all partial responses. The modalities for treatment included superficial X rays, Cobalt-60 or electron beam irradiation. The total tumor doses employed ranged from 600-4000 cGy. The 110 lesions (14 patients) were retrospectively analyzed to determine the dose required for local control of the lesions. Fifty-three percent of the lesions were classified as plaques, 20% as tumors less than or equal to 3 cm in diameter, and 27% as tumors greater than 3 cm in diameter. Complete response to treatment was observed in 95% of the plaque lesions, 95% of the tumors less than or equal to 3 cm in diameter and 93% of tumor greater than 3 cm in diameter. A complete response to treatment was noted in all lesions receiving greater than 2000 cGy. In the total population of lesions having a complete response, a local infield recurrence rate of 42% was noted in the group receiving less than or equal to 1000 cGy, 32% in those receiving 1001-2000 cGy, 21% in those receiving 2001-3000 cGy, and 0% in the group receiving greater than 3000 cGy. No infield recurrence was seen when the treated lesion received a total tumor dose greater than or equal to TDF of 49. Of those lesions which recurred, the mean time to recurrence for the first three dose ranges above were 5 months, 10 months and 16 months respectively. Eighty-three percent of the 30 recurrences were seen within one year of treatment; 100% of the recurrences occurred within two years of treatment. The data from this study indicate that tumor doses equivalent to at least 3000 cGy at 200 cGy per fraction, five fractions per week (TDF greater than or equal to 49) are needed for adequate local control of cutaneous mycosis fungoides lesions.