surgery vs radiation

Radiation versus Surgery

* Surgery allows histopathologic analysis of the nodes, thus leading to more accurate staging of the cancer and determination of potential further treatment requirements.
* The choice of treatment of the primary tumor.
* If radiation therapy is used as the initial primary treatment modality
for early SCC of the oral cavity, this will exhaust its use in the event of
future recurrence.
* Surgical salvage for recurrent cancer in an irradiated field can be very challenging.

* Radiation therapy also has potentially significant morbidity associated with the treatment, including osteoradionecrosis, mucositis, xerostomia, dysphagia, subcutaneous fibrosis, and poor wound healing. This can lead to a more prolonged and difficult recovery than occurs with end

Postoperative follow up:

Postoperative visit Examination schedule
0-3 months Biweekly examination
3-12 months Monthly examination
1-2 years Examination every 2 months
2-4 years Examination every 4 months
4-5 years Examination every 6 months


Radiotherapy
It uses ionizing radiation; it is loco-regional treatment and should be considered as complementary to surgery rather than competitive. The rationale of radiotherapy:
*Cells are killed in mitosis.
*Cancer cells divide more frequently.
*Malignant cells repair less efficiently.
*It preserves function

The basic principle is to achieve high dose in the tumor while minimizing the dose to the normal tissues, this is difficult in the head and neck because:
1. SCC is less sensitive to radiation than other types of malignancies requiring higher dose.
2. Better technique precision is required due to the juxtaposition of critically radiosensitive organs like the eyes and the brainstem. So the therapeutic ratio, defined as the relationship between the dose that is required for cure and the dose that causes unacceptable changes, is low.
Radiotherapy can be used as a definitive treatment or combined with other modalities, surgery or chemotherapy. It is best at eradicating small volumes of disease but it is more likely to fail if there is a large bulky tumor.

Types of radiotherapy

1. External beam radiotherapy (Teletherapy ).
2. Brachytherapy.
3. Unsealed radionuclide radiotherapy

Preoperative radiotherapy:

Preoperative radiotherapy is infrequently used and should not be considered to be a standard of care. It can be considered in the following situations:

1. Fixed, inoperable neck nodes.

2. In situations where the initiation of postoperative radiotherapy is
likely to be delayed by more than 6-8 weeks due to the need for extensive surgical reconstruction.
3. Prior to surgical approaches that will occasion the use of the gastric pull-up for reconstruction.
4. In patients who have undergone an open, incisional biopsy of a
positive neck node.


Postoperative radiotherapy:
It should start no later than 6 weeks after surgery.
-Absolute indications for postoperative irradiation are; involved (positive) margins at the primary tumor resection site and extracapsular spread of involved lymph nodes.
- Near absolute indications include close (less than 5 mm) margins,
two or more involved cervical lymph nodes and invasion of the soft
tissues of the neck.
- The relative indications include: the presence of lympho-vascular
space invasion and peri-neural invasion.

Techniques of radiotherapy:

Brachytherapy (internal radiotherapy) Brachytherapy describes the situation in which radioactive sources are brought close to the tumor mass (or even implanted within it) to deliver a highly localized radiation dose, it uses radioactive isotopes e.g. Radium, Iridium or Radon. Its approaches include:

1. Interstitial brachytherapy: in which radioactive sources are inserted directly in to tumor-bearing tissues (e.g., the tongue).
2. Intraluminal brachytherapy: in which the radioactive source is placed within a hollow viscus (e.g., the nasopharynx)
3. Surface molds: in which the radioactive source is placed close to
disease on the skin surface or lip.

- Conventional (external beam or teletherapy) radiotherapy

the patient who is a distance away. It uses photons (like X-rays or In which a beam of radiation is directed toward the tumor bearing part of Gamma rays) or particles like protons.

- 3-Dimensional conformal radiotherapy

In this planning technique a CT scan is taken with the patient immobilized in the radiotherapy treatment position. Data from these scans provide the radiation oncologist with precise anatomical and electron density data on tumor and normal tissues


Intensity modulated radiotherapy (IMRT)
This is an advanced approach to three-dimensional conformal radiotherapy. It optimizes the delivery of irradiation to irregularly shaped volumes and has the ability to treat concave volumes. IMRT uses sophisticated computer software and hardware to vary the shape and intensity of radiation delivered to different parts of the treatment volume.

Fractionation of radiotherapy:

Since the maximum radiation in a single dose is limited by the normal tissue tolerance. the total dose is divided into a number of small doses (fractions):
- Conventional: 65 Gy (Gray) is given in protracted treatment course of 2 Gy x 30 fractions for 42 days (conventional).
- Hyperfractionation : when the number of fractions is increased beyond the conventional levels, so the ratio of dose/ fraction is reduced. The treatment should be given 2-3 times/day with 6 hours interval.

- Acceleration: is reduction in overall treatment time.

- Continuous hyperfractionated accelerated radiation therapy: (CHART): 12 days, 3 fractions/ day, 7 days/week. This is given to prevent repopulation of malignant cells.
- Split courses: designed to reduce the severity of mucosal reaction, so the radiotherapy course is divided into 2 halves separated by 2 weeks, but this may lead to repopulation of tumor cells so it is condemned.

Chemotherapy

In SCC of the head and neck chemotherapy is used in combination with radiotherapy and/or surgery in radical treatment or alone in palliative treatment. Failure of cancer treatment is due to inherent or acquired resistance of malignant cells

Classes of chemotherapeutic agents:

In general, they are grouped as:
Antimetabolites: this group predominantly interferes with synthesis and metabolism of DNA and to some extent, RNA. It includes:
Methotrexate, 5-fluorouracil (5-FU), cytarabine , gemcitabine and 6 mercaptopurine (6MP).

DNA damaging agents; these include:

Alkylating agents like cyclophosphamide and ifosfamide and melphalan.
Antibiotics like adriamycin, mitomycin, actinomycin D and bleomycin; nitrosoureas (such as BCNU and CCNU).
Platinum derivatives like cisplatin and carboplatin.


Mitosis inhibitors; this group includes Vinca alkaloids (like vincristine and vinblastine) and taxanes (Taxol).
Cancer cell enzyme inactivators; this is a new class, recently discovered and undergoing much research, e.g., Tyrosine kinase inhibitors code-named STI 571 (trade name Gleevec or Glivec).
Tyrosine kinase is an essential for malignant cell reproduction.

- Scheduling of Chemotherapy

Before radiotherapy (Neoadjuvant or Induction).
During radiotherapy (Synchronous or Concomitant).
After radiotherapy (Adjuvant or Subsequent).
Chemotherapy can be given as a single agent with reported response rate of 40% or in combination with response rate of 75% The main outcome measures are.
Local control.
Survival rate.

Concomitant ChemoradiationUse of concomitant chemo-radiotherapy is based on a belief thatchemotherapy synergistically acts with radiotherapy by:1. Inhibiting repair of DNA damage caused by radiotherapy, arresting cells in radiosensitive phases and possibly preventing regrowth between radiotherapy treatments.2. In addition it is thought that chemotherapy may treat radio-resistant tumor.The addition of concomitant chemotherapy to radiotherapy has beenshown to be superior to radiotherapy alone for loco-regional control and survival in head and neck SCC

Palliative treatment and terminal care:

Treatment is usually radical in intent; also any salvage treatment is
aimed to cure the patient. The treatment may progress to palliative and finally to terminal care which is a right to every patient and duty of every health professional. The aim of terminal care is to:
1. Make the patient free of pain.
2. Mobile.
3. Sufficiently alert.
It is usually home care, in a hospice or in the same hospital.