Rhabdomysarcoma

Physical examination Complete blood cell count Liver function tests Renal function tests Urinalysis Chest xray Thoracic CT scan Bone scan MRI/CT of primary tumor Bone marrow biopsy Lumbar puncture Pelvic examination || T2 – Regional extension beyond site of organ of origin a - ≤ 5 cm b - > 5 cm  N0 – No evidence of regional node involvement N1 – Evidence of regional node involvement (enlargement of nodes on radiographic imaging is considered evidence of involvement, although histologic confirmation is recommended when possible) M0 – No distant metastasis M1 – Evidence of distant metastasis ||
 * **Epidemiolgy:** || Rhabdomyosarcoma is a rare form of cancer that commonly occurs in children younger than fifteen years old. In the United States, about 650 cases are reported annually. Rhabdomyosarcoma is the most common soft tissue sarcoma found in children.[1,2] ||
 * **Etiology:** || The major cause of rhabdomyosarcoma is unknown. Some research has shown that parental use of marijuana and cocaine before pregnancy is highly associated with the development of rhabdomyosarcoma.[2] ||
 * **Signs & Symptoms:** || Symptoms at the time of presentation are related to the primary site of the tumors. The symptoms of tumors that arise from the parameningeal area include; cranial nerve palsy, facial pain and swelling, nasal voice, mouth breathing, and trimus. Tumors that arise in the head and neck typically present as a palpable mass that can cause nerve palsy. The second most common site of rhabdomyosarcoma is the genitourinary area. A common symptom in this tumor site is bladder distension.[2] ||
 * **Diagnostic Procedures:** || The following are recommended diagnostic procedures for various sites: [1]
 * **Histology:** || The four histologic subtypes of rhabdomyosarcomas are: embryonal, botryoid, alveolar and pleomorphic. Patients with embryonal rhabdomyosarcoma have intermediate outcome. Embryonal histology occurs in 60% of cases and is found most commonly in the orbit, head and neck and genitourinary sites. The botryoid subtype has a grapelike appears and is usually noninvasive and localized. It presents in mucosal lined organs such as the vagina, urinary bladder, middle ear, biliary tree and nasopharynx. Alveolar and undifferentiated sarcomas usually have a poor prognosis. The pleomorphic type is extremely rare. [1] ||
 * **Lymph node drainage:** || Lymph node metastasis for orbital tumors are rare. Extremity tumors have a high probability of lymphatic metastasis. For paratesticular tumors, periaortic and ipsilateral iliac nodes may be involved. [1] ||
 * **Metastatic spread:** || It is most common for these patients to have hematogenous metastases. Lung is where this occurs most frequently. Both bone and bone marrow are common. Unusual sites such as the heart, breast, and cutaneous tissues can occur. Brain metastases at the time of diagnosis are rare. [1] ||
 * **Grading:** || In high-grade tumors, the cells look very abnormal. They are likely to grow more quickly and are more likely to spread. While there is no specific grading system for rhabdomyosarcomas., embryonal and alveolar types of rhabdomyosarcoma are always high-grade.[1] ||
 * **Staging:** || T1 – Tumor confined to site or organ of origin
 * **Radiation side effects:** || Side effects from radiation include radiation damage to: small bowel, kidneys, and liver. There is also a possibility that the patient will develop second malignancies from the radiation treatment.[1] ||
 * **Prognosis:** || Poor prognostic factors include tumor size greater than 5 cm, alveolar or undifferentiated histology, primary site and treatment modalities. [1] ||
 * **Treatments:** || Multidisciplinary approach with surgery, chemotherapy and radiation leads to the best treatment outcomes. [1]

Radiation ports should include soft tissue extent at presentation with margins. 3D conformal treatment is optimal field arrangement. [1]

Radiation doses: Residual disease: 50.4 - 55.8 Gy Combined chemoradiation: 40 - 41.4 Gy  Brain or spinal cord: 30 Gy [1]

Orbit: High dose radiation (45-50 Gy) provides good local control, the addition of chemotherapy improves outcomes. [1]

Head and Neck (nasopharynx, nasal cavity, paranasal sinuses, middle ear, pterygopalatine fossa and infratemporal fossa): Radiation to local fields with margins. Craniospinal irradiation is necessary with neuraxis dissemination. [1]

Head and Neck (scalp, parotid, oral cavity, larynx, oropharynx, and cheek): Complete surgical resection. Radiation use is based on the extent of residual disease. Draining lymph nodes are not typically irradiated unless metastatic. [1]

Bladder and Prostate: Anterior pelvic exenteration combined with chemotherapy and radiation for residual disease. [1,3] Partial cystectomy for small tumors arising from the dome of the bladder. [1]

Paratesticular: Early stage disease may be completely resected with good control rates. Regional lymph node irradiation to the periaortic and ipsilateral iliac nodes is recommended. Tumor extension to the scrotum is an indication for irradiation. [1]

Gynecological Tumors (vulva, vagina, cervix, and uterus): Surgery is primarily used for diagnosis, but resection may be possible. Very sensitive to chemotherapy and may not need irradiation for tumor control. Radiation is typically reserved for residual disease after surgical resection. Intracavitary and interstitial brachytherapy is very useful for these tumors. [1]

Other Pelvic Sites (perianal, perirectal, and perineal): Lymph node involvement is common. Chemotherapy and radiation are recommended when exenteration is needed. [1]

Extremities: Complete surgical resection with limb salvage is recommended. Chemotherapy and radiation are recommended for local control. [1] || Brainstem: 60 Gy Parotid: 32 Gy  Ear: 55 Gy  Larynx: 45 Gy  Lens: 10 Gy  Optic chiasm: 50 Gy  Optic nerve: 50 Gy  Kidney: 50 Gy  Liver: 50 Gy  Small bowel: 50 Gy  Colon: 55 Gy  Bladder: 65 Gy [4] || [2] Hoppe TR, Phillips LT, Roach M. //Leibel and Phillips Textbook of Radiation Oncology//. 3rd Edition. Philadelphia, PA: Elsevie;. 2010. [3] Pelvic Exenteration. http://en.wikipedia.org/wiki/Pelvic_exenteration. Accessed June 30, 2012. [4] Use of Normal Tissue Tolerance Doses into Linear Quadratic Equation to Estimate Normal Tissue Complication Probability. Sanchez Cancer Center. http://www.rooj.com/Radiation%20Tissue%20Tolerance.htm. Accessed June 30, 2012. || Back to Week 6
 * **TD 5/5:** || Brain: 60 Gy
 * **References:** || [1] Chao C. //Radiation Oncology Management Decisions//. 2nd ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2002.