Dog Parvo Symptoms

Intrathoracic tumors:

Long-term tumor control has been obtained with surgical resection of Thymomas. However, about 50% are not resectable. Although limited data is available, tumor remission has been reported following radiation therapy alone or combined with surgery (either before or after). When both modalities are used in combination, it is suggested that radiation be performed before surgery to avoid possibly increasing the amount of hypoxic cells created by surgery-induced tumor vasculature damage.

Mediastinal lymphoma refractory to chemotherapy has been treated with radiation therapy with variable results. Many go on to developing systemic signs shortly after treatment. However, while limited data exists, some cases of primary mediastinal lymphoma have responded well to radiation therapy on initial diagnosis with adjuvant chemotherapy for potential systemic disease.

Other thoracic tumors such as Chemodectomas, imcompletely resected Right atrial hemangiosarcomas, incompletely resected primary Lung tumors, and other heart base or mediastinal tumors have been approached with combination of surgery and radiation +/- chemotherapy. Data on treating these tumors is very limited and the decision to treat with radiation alone, or as part of a combination, should be based on a case-by-case basis using the basic principles of radiation oncology.

Abdominal and Perianal tumors:

Very little data is available on radiation therapy of bladder tumors. Transitional cell carcinomasof the bladder have been successfully treated with a combination of radiation and chemotherapy (+/- surgery) with a median survival time of almost 1 year.

As with bladder tumors, data on radiation therapy of Anal sac adenocarcinomas is scarce. They are, however, commonly treated with a combination of radiation and chemotherapy with a median survival time of over1 year. These tumors have a relatively high metastatic potential, with approximately 50% of patients first presenting with evidence of iliac/sublumbar lymphatic metastasis. Therefore, the sublumbar region is included in the radiation treatment field. Chemotherapy is also recommended as an adjuvant to treat metastatic disease even if not clinically evident.

Other Perianal tumors such as Perianal gland adenomas and adenocarcinomas, most often occurring in males, are best treated with surgical resection (aggressive when malignant). When good margins cannot be obtained on adenocarcinomas, radiation therapy is recommended. Regional lymph node metastasis is common. Some 50% are successfully surgically resected, but radiation therapy in combination with chemotherapy should result in a prolonged remission interval in non-resectable cases.

Prostatic tumors and Testicular tumors of retained testicles or lymphatic metastasis of either type can be treated with radiation therapy. Primary testicular tumors and testicular tumor lymphatic metastasis has been successfully treated with radiation therapy. The prognosis greatly depends on the extent of the local invasion and the degree of metastasis at presentation. Prostatic tumors, on the other hand, usually have a poor prognosis no matter what treatment modality is used. Approximately 70-80% already have advanced skeletal metastatic disease of the lumbar spine, sacrum and/or pelvis on presentation, or extensive local invasion of the urethra, bladder or colon. Radiation therapy has been attempted on occasion, however data is limited. For the most part, treatment of these cases are usually geared toward a palliative intent.